10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q

(Mark One)

ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2018

OR

¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from              to

________________________

Commission file number	Registrant, State of Incorporation or Organization, Address of Principal Executive Offices and Telephone Number	IRS Employer Identification No.
1-32853	DUKE ENERGY CORPORATION (a Delaware corporation) 550 South Tryon Street Charlotte, North Carolina 28202-1803 704-382-3853	20-2777218

Commission file number	Registrant, State of Incorporation or Organization, Address of Principal Executive Offices, Telephone Number and IRS Employer Identification Number	Commission file number	Registrant, State of Incorporation or Organization, Address of Principal Executive Offices, Telephone Number and IRS Employer Identification Number
1-4928	DUKE ENERGY CAROLINAS, LLC (a North Carolina limited liability company) 526 South Church Street Charlotte, North Carolina 28202-1803 704-382-3853 56-0205520	1-3274	DUKE ENERGY FLORIDA, LLC (a Florida limited liability company) 299 First Avenue North St. Petersburg, Florida 33701 704-382-3853 59-0247770
1-15929	PROGRESS ENERGY, INC. (a North Carolina corporation) 410 South Wilmington Street Raleigh, North Carolina 27601-1748 704-382-3853 56-2155481	1-1232	DUKE ENERGY OHIO, INC. (an Ohio corporation) 139 East Fourth Street Cincinnati, Ohio 45202 704-382-3853 31-0240030
1-3382	DUKE ENERGY PROGRESS, LLC (a North Carolina limited liability company) 410 South Wilmington Street Raleigh, North Carolina 27601-1748 704-382-3853 56-0165465	1-3543	DUKE ENERGY INDIANA, LLC (an Indiana limited liability company) 1000 East Main Street Plainfield, Indiana 46168 704-382-3853 35-0594457
1-6196	PIEDMONT NATURAL GAS COMPANY, INC. (a North Carolina corporation) 4720 Piedmont Row Drive Charlotte, North Carolina 28210 704-364-3120 56-0556998

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Duke Energy Corporation (Duke Energy)	Yesx	No ¨	Duke Energy Florida, LLC (Duke Energy Florida)	Yesx	No ¨
Duke Energy Carolinas, LLC (Duke Energy Carolinas)	Yesx	No ¨	Duke Energy Ohio, Inc. (Duke Energy Ohio)	Yesx	No ¨
Progress Energy, Inc. (Progress Energy)	Yesx	No ¨	Duke Energy Indiana, LLC (Duke Energy Indiana)	Yesx	No ¨
Duke Energy Progress, LLC (Duke Energy Progress)	Yesx	No ¨	Piedmont Natural Gas Company, Inc. (Piedmont)	Yesx	No ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).

Duke Energy	Yesx	No ¨	Duke Energy Florida	Yesx	No ¨
Duke Energy Carolinas	Yesx	No ¨	Duke Energy Ohio	Yesx	No ¨
Progress Energy	Yesx	No ¨	Duke Energy Indiana	Yesx	No ¨
Duke Energy Progress	Yesx	No ¨	Piedmont	Yesx	No ¨

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and "emerging growth company" in Rule 12b-2 of the Exchange Act.

Duke Energy	Large accelerated filerx	Accelerated filer ¨	Non-accelerated filer ¨	Smaller reporting company ¨	Emerging Growth Company ¨
Duke Energy Carolinas	Large accelerated filer ¨	Accelerated filer ¨	Non-accelerated filerx	Smaller reporting company ¨	Emerging Growth Company ¨
Progress Energy	Large accelerated filer ¨	Accelerated filer ¨	Non-accelerated filerx	Smaller reporting company ¨	Emerging Growth Company ¨
Duke Energy Progress	Large accelerated filer ¨	Accelerated filer ¨	Non-accelerated filerx	Smaller reporting company ¨	Emerging Growth Company ¨
Duke Energy Florida	Large accelerated filer ¨	Accelerated filer ¨	Non-accelerated filerx	Smaller reporting company ¨	Emerging Growth Company ¨
Duke Energy Ohio	Large accelerated filer ¨	Accelerated filer ¨	Non-accelerated filerx	Smaller reporting company ¨	Emerging Growth Company ¨
Duke Energy Indiana	Large accelerated filer ¨	Accelerated filer ¨	Non-accelerated filerx	Smaller reporting company ¨	Emerging Growth Company ¨
Piedmont	Large accelerated filer ¨	Accelerated filer ¨	Non-accelerated filerx	Smaller reporting company ¨	Emerging Growth Company ¨

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ¨

Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).

Duke Energy	Yes ¨	Nox	Duke Energy Florida	Yes ¨	Nox
Duke Energy Carolinas	Yes ¨	Nox	Duke Energy Ohio	Yes ¨	Nox
Progress Energy	Yes ¨	Nox	Duke Energy Indiana	Yes ¨	Nox
Duke Energy Progress	Yes ¨	Nox	Piedmont	Yes ¨	Nox

Number of shares of Common stock outstanding at March 31, 2018:

Registrant	Description	Shares
Duke Energy	Common stock, $0.001 par value	701,007,267

This combined Form 10-Q is filed separately by eight registrants: Duke Energy, Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, Duke Energy Indiana and Piedmont (collectively the Duke Energy Registrants). Information contained herein relating to any individual registrant is filed by such registrant solely on its own behalf. Each registrant makes no representation as to information relating exclusively to the other registrants.

Duke Energy Carolinas, Progress Energy, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, Duke Energy Indiana and Piedmont meet the conditions set forth in General Instructions H(1)(a) and (b) of Form 10-Q and are therefore filing this form with the reduced disclosure format specified in General Instructions H(2) of Form 10-Q.

TABLE OF CONTENTS

	Cautionary Statement Regarding Forward-Looking Information
PART I. FINANCIAL INFORMATION
Item 1.	Financial Statements
	Duke Energy Corporation Financial Statements	6
	Duke Energy Carolinas, LLC Financial Statements	11
	Progress Energy, Inc. Financial Statements	15
	Duke Energy Progress, LLC Financial Statements	19
	Duke Energy Florida, LLC Financial Statements	23
	Duke Energy Ohio, Inc. Financial Statements	27
	Duke Energy Indiana, LLC Financial Statements	31
	Piedmont Natural Gas Company, Inc. Financial Statements	35
	Combined Notes to Condensed Consolidated Financial Statements
	Note 1 – Organization and Basis of Presentation	39
	Note 2 – Business Segments	43
	Note 3 – Regulatory Matters	45
	Note 4 – Commitments and Contingencies	52
	Note 5 – Debt and Credit Facilities	57
	Note 6 – Goodwill	58
	Note 7 – Related Party Transactions	59
	Note 8 – Derivatives and Hedging	60
	Note 9 – Investments in Debt and Equity Securities	66
	Note 10 – Fair Value Measurements	72
	Note 11 – Variable Interest Entities	79
	Note 12 – Revenue	84
	Note 13 – Common Stock	87
	Note 14 – Stock-Based Compensation	88
	Note 15 – Employee Benefit Plans	89
	Note 16 – Income Taxes	91
	Note 17 – Subsequent Events	91
Item 2.	Management's Discussion and Analysis of Financial Condition and Results of Operations	92
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	115
Item 4.	Controls and Procedures	115
PART II. OTHER INFORMATION
Item 1.	Legal Proceedings	116
Item 1A.	Risk Factors	116
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	116
Item 6.	Exhibits	117
	Signatures	120

CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING INFORMATION

This document includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Forward-looking statements are based on management’s beliefs and assumptions and can often be identified by terms and phrases that include “anticipate,” “believe,” “intend,” “estimate,” “expect,” “continue,” “should,” “could,” “may,” “plan,” “project,” “predict,” “will,” “potential,” “forecast,” “target,” “guidance,” “outlook” or other similar terminology. Various factors may cause actual results to be materially different than the suggested outcomes within forward-looking statements; accordingly, there is no assurance that such results will be realized. These factors include, but are not limited to:

◦ State, federal and foreign legislative and regulatory initiatives, including costs of compliance with existing and future environmental requirements, including those related to climate change, as well as rulings that affect cost and investment recovery or have an impact on rate structures or market prices;

◦ The extent and timing of costs and liabilities to comply with federal and state laws, regulations and legal requirements related to coal ash remediation, including amounts for required closure of certain ash impoundments, are uncertain and difficult to estimate;

◦ The ability to recover eligible costs, including amounts associated with coal ash impoundment retirement obligations and costs related to significant weather events, and to earn an adequate return on investment through rate case proceedings and the regulatory process;

◦ The costs of decommissioning Crystal River Unit 3 and other nuclear facilities could prove to be more extensive than amounts estimated and all costs may not be fully recoverable through the regulatory process;

◦ Costs and effects of legal and administrative proceedings, settlements, investigations and claims;

◦ Industrial, commercial and residential growth or decline in service territories or customer bases resulting from sustained downturns of the economy and the economic health of our service territories or variations in customer usage patterns, including energy efficiency efforts and use of alternative energy sources, such as self-generation and distributed generation technologies;

◦ Federal and state regulations, laws and other efforts designed to promote and expand the use of energy efficiency measures and distributed generation technologies, such as private solar and battery storage, in Duke Energy service territories could result in customers leaving the electric distribution system, excess generation resources as well as stranded costs;

◦ Advancements in technology;

◦ Additional competition in electric and natural gas markets and continued industry consolidation;

◦ The influence of weather and other natural phenomena on operations, including the economic, operational and other effects of severe storms, hurricanes, droughts, earthquakes and tornadoes, including extreme weather associated with climate change;

◦ The ability to successfully operate electric generating facilities and deliver electricity to customers including direct or indirect effects to the company resulting from an incident that affects the U.S. electric grid or generating resources;

◦ The ability to complete necessary or desirable pipeline expansion or infrastructure projects in our natural gas business;

◦ Operational interruptions to our natural gas distribution and transmission activities;

◦ The availability of adequate interstate pipeline transportation capacity and natural gas supply;

◦ The impact on facilities and business from a terrorist attack, cybersecurity threats, data security breaches and other catastrophic events, such as fires, explosions, pandemic health events or other similar occurrences;

◦ The inherent risks associated with the operation of nuclear facilities, including environmental, health, safety, regulatory and financial risks, including the financial stability of third-party service providers;

◦ The timing and extent of changes in commodity prices and interest rates and the ability to recover such costs through the regulatory process, where appropriate, and their impact on liquidity positions and the value of underlying assets;

◦ The results of financing efforts, including the ability to obtain financing on favorable terms, which can be affected by various factors, including credit ratings, interest rate fluctuations, compliance with debt covenants and conditions and general market and economic conditions;

◦ Credit ratings of the Duke Energy Registrants may be different from what is expected;

◦ Declines in the market prices of equity and fixed-income securities and resultant cash funding requirements for defined benefit pension plans, other post-retirement benefit plans and nuclear decommissioning trust funds;

◦ Construction and development risks associated with the completion of the Duke Energy Registrants’ capital investment projects, including risks related to financing, obtaining and complying with terms of permits, meeting construction budgets and schedules and satisfying operating and environmental performance standards, as well as the ability to recover costs from customers in a timely manner, or at all;

◦ Changes in rules for regional transmission organizations, including changes in rate designs and new and evolving capacity markets, and risks related to obligations created by the default of other participants;

◦ The ability to control operation and maintenance costs;

◦ The level of creditworthiness of counterparties to transactions;

◦ Employee workforce factors, including the potential inability to attract and retain key personnel;

◦ The ability of subsidiaries to pay dividends or distributions to Duke Energy Corporation holding company (the Parent);

◦ The performance of projects undertaken by our nonregulated businesses and the success of efforts to invest in and develop new opportunities;

◦ The effect of accounting pronouncements issued periodically by accounting standard-setting bodies;

◦ The impact of new U.S. tax legislation to our financial condition, results of operations or cash flows and our credit ratings;

◦ The impacts from potential impairments of goodwill or equity method investment carrying values;

◦ The ability to successfully complete future merger, acquisition or divestiture plans; and

◦ The ability to implement our business strategy.

Additional risks and uncertainties are identified and discussed in the Duke Energy Registrants' reports filed with the SEC and available at the SEC's website at sec.gov. In light of these risks, uncertainties and assumptions, the events described in the forward-looking statements might not occur or might occur to a different extent or at a different time than described. Forward-looking statements speak only as of the date they are made and the Duke Energy Registrants expressly disclaim an obligation to publicly update or revise any forward-looking statements, whether as a result of new information, future events or otherwise.

PART I. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

DUKE ENERGY CORPORATION

Condensed Consolidated Statements of Operations

(Unaudited)

	Three Months Ended
	March 31,
(in millions, except per-share amounts)	2018			2017
Operating Revenues
Regulated electric	$	5,284		$	4,913
Regulated natural gas	700			646
Nonregulated electric and other	151			170
Total operating revenues	6,135			5,729
Operating Expenses
Fuel used in electric generation and purchased power	1,676			1,449
Cost of natural gas	313			258
Operation, maintenance and other	1,464			1,468
Depreciation and amortization	967			859
Property and other taxes	316			304
Impairment charges	43			—
Total operating expenses	4,779			4,338
(Loss) Gains on Sales of Other Assets and Other, net	(100		)	11
Operating Income	1,256			1,402
Other Income and Expenses
Equity in (losses) earnings of unconsolidated affiliates	(24		)	29
Other income and expenses, net	86			121
Total other income and expenses	62			150
Interest Expense	515			491
Income Before Income Taxes	803			1,061
Income Tax Expense	181			344
Net Income	622			717
Less: Net Income Attributable to Noncontrolling Interests	2			1
Net Income Attributable to Duke Energy Corporation	$	620		$	716
Earnings Per Share – Basic and Diluted
Net income attributable to Duke Energy Corporation common stockholders
Basic	$	0.88		$	1.02
Diluted	$	0.88		$	1.02
Weighted average shares outstanding
Basic	701			700
Diluted	701			700

See Notes to Condensed Consolidated Financial Statements

6

PART I

DUKE ENERGY CORPORATION

Condensed Consolidated Statements of Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
Net Income	$	622		$	717
Other Comprehensive Income, net of tax
Pension and OPEB adjustments	1			1
Net unrealized gains on cash flow hedges	12			2
Reclassification into earnings from cash flow hedges	1			1
Unrealized (losses) gains on available-for-sale securities	(3		)	4
Other Comprehensive Income, net of tax	11			8
Comprehensive Income	633			725
Less: Comprehensive Income Attributable to Noncontrolling Interests	2			1
Comprehensive Income Attributable to Duke Energy Corporation	$	631		$	724

See Notes to Condensed Consolidated Financial Statements

7

PART I

DUKE ENERGY CORPORATION

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	421		$	358
Receivables (net of allowance for doubtful accounts of $17 at 2018 and $14 at 2017)	759			779
Receivables of VIEs (net of allowance for doubtful accounts of $57 at 2018 and $54 at 2017)	1,984			1,995
Inventory	3,149			3,250
Regulatory assets (includes $51 at 2018 and 2017 related to VIEs)	1,544			1,437
Other	422			634
Total current assets	8,279			8,453
Property, Plant and Equipment
Cost	129,281			127,507
Accumulated depreciation and amortization	(42,307		)	(41,537		)
Generation facilities to be retired, net	399			421
Net property, plant and equipment	87,373			86,391
Other Noncurrent Assets
Goodwill	19,396			19,396
Regulatory assets (includes $1,082 at 2018 and $1,091 at 2017 related to VIEs)	12,218			12,442
Nuclear decommissioning trust funds	7,024			7,097
Investments in equity method unconsolidated affiliates	1,189			1,175
Other	3,062			2,960
Total other noncurrent assets	42,889			43,070
Total Assets	$	138,541		$	137,914
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	2,391		$	3,043
Notes payable and commercial paper	2,969			2,163
Taxes accrued	422			551
Interest accrued	542			525
Current maturities of long-term debt (includes $225 at 2018 and 2017 related to VIEs)	3,951			3,244
Asset retirement obligations	676			689
Regulatory liabilities	505			402
Other	1,542			1,865
Total current liabilities	12,998			12,482
Long-Term Debt (includes $4,275 at 2018 and $4,306 at 2017 related to VIEs)	49,030			49,035
Other Noncurrent Liabilities
Deferred income taxes	6,855			6,621
Asset retirement obligations	9,484			9,486
Regulatory liabilities	15,283			15,330
Accrued pension and other post-retirement benefit costs	1,018			1,103
Investment tax credits	537			539
Other	1,538			1,581
Total other noncurrent liabilities	34,715			34,660
Commitments and Contingencies
Equity
Common stock, $0.001 par value, 2 billion shares authorized; 701 million shares outstanding at 2018 and 700 million shares outstanding at 2017	1			1
Additional paid-in capital	38,839			38,792
Retained earnings	3,021			3,013
Accumulated other comprehensive loss	(69		)	(67		)
Total Duke Energy Corporation stockholders' equity	41,792			41,739
Noncontrolling interests	6			(2		)
Total equity	41,798			41,737
Total Liabilities and Equity	$	138,541		$	137,914

See Notes to Condensed Consolidated Financial Statements

8

PART I

DUKE ENERGY CORPORATION

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	622		$	717
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,089			991
Equity component of AFUDC	(55		)	(62		)
Losses (gains) on sales of other assets	100			(11		)
Impairment charges	43			—
Deferred income taxes	199			342
Equity in losses (earnings) of unconsolidated affiliates	24			(29		)
Accrued pension and other post-retirement benefit costs	15			6
Contributions to qualified pension plans	(141		)	—
Payments for asset retirement obligations	(122		)	(134		)
Payment for disposal of other assets	(105		)	—
Other rate case adjustments	37			—
Provision for rate refunds	158			—
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	4			(38		)
Receivables	64			343
Inventory	101			155
Other current assets	27			(22		)
Increase (decrease) in
Accounts payable	(327		)	(463		)
Taxes accrued	(107		)	(28		)
Other current liabilities	(171		)	(478		)
Other assets	(59		)	(45		)
Other liabilities	(5		)	2
Net cash provided by operating activities	1,391			1,246
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,087		)	(2,160		)
Cost of removal, net of salvage	(81		)	(39		)
Contributions to equity method investments	(74		)	(175		)
Purchases of debt and equity securities	(958		)	(1,386		)
Proceeds from sales and maturities of debt and equity securities	930			1,405
Other	6			(6		)
Net cash used in investing activities	(2,264		)	(2,361		)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the:
Issuance of long-term debt	1,240			1,563
Issuance of common stock	21			—
Payments for the redemption of long-term debt	(487		)	(408		)
Proceeds from the issuance of short-term debt with original maturities greater than 90 days	135			25
Payments for the redemption of short-term debt with original maturities greater than 90 days	(50		)	(7		)
Notes payable and commercial paper	706			1,045
Dividends paid	(599		)	(600		)
Other	(19		)	(22		)
Net cash provided by financing activities	947			1,596
Net increase in cash, cash equivalents and restricted cash	74			481
Cash, cash equivalents and restricted cash at beginning of period	505			541
Cash, cash equivalents and restricted cash at end of period	$	579		$	1,022
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	799		$	575
Non-cash dividends	26			—

See Notes to Condensed Consolidated Financial Statements

9

PART I

DUKE ENERGY CORPORATION

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

									Accumulated Other Comprehensive Loss
												Net Unrealized						Total
									Net Gains			(Losses) Gains						Duke Energy
	Common			Additional					(Losses) on			on Available-			Pension and			Corporation
	Stock	Common		Paid-in		Retained			Cash Flow			for-Sale-			OPEB			Stockholders'			Noncontrolling			Total
(in millions)	Shares	Stock		Capital		Earnings			Hedges			Securities			Adjustments			Equity			Interests			Equity
Balance at December 31, 2016	700	$	1	$	38,741	$	2,384		$	(20	)	$	(1	)	$	(72	)	$	41,033		$	8		$	41,041
Net income	—	—		—		716			—			—			—			716			1			717
Other comprehensive income	—	—		—		—			3			4			1			8			—			8
Common stock issuances, including dividend reinvestment and employee benefits	—	—		1		—			—			—			—			1			—			1
Common stock dividends	—	—		—		(600		)	—			—			—			(600		)	—			(600		)
Distributions to noncontrolling interest in subsidiaries	—	—		—		—			—			—			—			—			(2		)	(2		)
Other(a)	—	—		—		21			—			—			—			21			—			21
Balance at March 31, 2017	700	$	1	$	38,742	$	2,521		$	(17	)	$	3		$	(71	)	$	41,179		$	7		$	41,186
Balance at December 31, 2017	700	$	1	$	38,792	$	3,013		$	(10	)	$	12		$	(69	)	$	41,739		$	(2	)	$	41,737
Net income	—	—		—		620			—			—			—			620			2			622
Other comprehensive income (loss)	—	—		—		—			13			(3		)	1			11			—			11
Common stock issuances, including dividend reinvestment and employee benefits	1	—		47		—			—			—			—			47			—			47
Common stock dividends	—	—		—		(625		)	—			—			—			(625		)	—			(625		)
Distributions to noncontrolling interest in subsidiaries	—	—		—		—			—			—			—			—			(1		)	(1		)
Other(b)	—	—		—		13			—			(13		)	—			—			7			7
Balance at March 31, 2018	701	$	1	$	38,839	$	3,021		$	3		$	(4	)	$	(68	)	$	41,792		$	6		$	41,798

(a) Cumulative-effect adjustment due to implementation of a new accounting standard related to stock-based compensation and the associated income taxes.

(b) Amounts in Retained Earnings and Accumulated Other Comprehensive Loss represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement. See Note 1 for more information.

See Notes to Condensed Consolidated Financial Statements

10

PART I

DUKE ENERGY CAROLINAS, LLC

Condensed Consolidated Statements of Operations and Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018		2017
Operating Revenues	$	1,763	$	1,716
Operating Expenses
Fuel used in electric generation and purchased power	473		428
Operation, maintenance and other	451		495
Depreciation and amortization	272		254
Property and other taxes	72		68
Impairment charges	13		—
Total operating expenses	1,281		1,245
Operating Income	482		471
Other Income and Expenses, net	39		50
Interest Expense	107		103
Income Before Income Taxes	414		418
Income Tax Expense	91		148
Net Income	$	323	$	270
Other Comprehensive Income, net of tax
Reclassification into earnings from cash flow hedges	1		—
Comprehensive Income	$	324	$	270

See Notes to Condensed Consolidated Financial Statements

11

PART I

DUKE ENERGY CAROLINAS, LLC

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	3		$	16
Receivables (net of allowance for doubtful accounts of $2 at 2018 and 2017)	194			200
Receivables of VIEs (net of allowance for doubtful accounts of $7 at 2018 and 2017)	634			640
Receivables from affiliated companies	106			95
Inventory	980			971
Regulatory assets	331			299
Other	42			19
Total current assets	2,290			2,240
Property, Plant and Equipment
Cost	43,562			42,939
Accumulated depreciation and amortization	(15,404		)	(15,063		)
Net property, plant and equipment	28,158			27,876
Other Noncurrent Assets
Regulatory assets	2,825			2,853
Nuclear decommissioning trust funds	3,734			3,772
Other	1,023			979
Total other noncurrent assets	7,582			7,604
Total Assets	$	38,030		$	37,720
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	726		$	842
Accounts payable to affiliated companies	259			209
Notes payable to affiliated companies	45			104
Taxes accrued	84			234
Interest accrued	144			108
Current maturities of long-term debt	805			1,205
Asset retirement obligations	281			337
Regulatory liabilities	116			126
Other	369			486
Total current liabilities	2,829			3,651
Long-Term Debt	9,589			8,598
Long-Term Debt Payable to Affiliated Companies	300			300
Other Noncurrent Liabilities
Deferred income taxes	3,493			3,413
Asset retirement obligations	3,318			3,273
Regulatory liabilities	6,208			6,231
Accrued pension and other post-retirement benefit costs	95			95
Investment tax credits	231			232
Other	532			566
Total other noncurrent liabilities	13,877			13,810
Commitments and Contingencies
Equity
Member's equity	11,441			11,368
Accumulated other comprehensive loss	(6		)	(7		)
Total equity	11,435			11,361
Total Liabilities and Equity	$	38,030		$	37,720

See Notes to Condensed Consolidated Financial Statements

12

PART I

DUKE ENERGY CAROLINAS, LLC

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	323		$	270
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amortization of nuclear fuel)	347			339
Equity component of AFUDC	(21		)	(30		)
Impairment charges	13			—
Deferred income taxes	80			162
Accrued pension and other post-retirement benefit costs	1			—
Contributions to qualified pension plans	(46		)	—
Payments for asset retirement obligations	(55		)	(65		)
Provision for rate refunds	61			—
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	—			3
Receivables	19			66
Receivables from affiliated companies	(11		)	54
Inventory	(9		)	4
Other current assets	(144		)	(26		)
Increase (decrease) in
Accounts payable	(76		)	(131		)
Accounts payable to affiliated companies	50			3
Taxes accrued	(129		)	(53		)
Other current liabilities	(23		)	(125		)
Other assets	12			(3		)
Other liabilities	(43		)	(2		)
Net cash provided by operating activities	349			466
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(621		)	(563		)
Cost of removal, net of salvage	(17		)	(16		)
Purchases of debt and equity securities	(494		)	(722		)
Proceeds from sales and maturities of debt and equity securities	494			722
Notes receivable from affiliated companies	—			66
Other	(4		)	(4		)
Net cash used in investing activities	(642		)	(517		)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	991			—
Payments for the redemption of long-term debt	(401		)	(113		)
Notes payable to affiliated companies	(59		)	337
Distributions to parent	(250		)	(175		)
Other	(1		)	(1		)
Net cash provided by financing activities	280			48
Net decrease in cash and cash equivalents	(13		)	(3		)
Cash and cash equivalents at beginning of period	16			14
Cash and cash equivalents at end of period	$	3		$	11
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	267		$	164

See Notes to Condensed Consolidated Financial Statements

13

PART I

DUKE ENERGY CAROLINAS, LLC

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

				Accumulated Other
				Comprehensive
				Loss
				Net Losses on
	Member's			Cash Flow			Total
(in millions)	Equity			Hedges			Equity
Balance at December 31, 2016	$	10,781		$	(9	)	$	10,772
Net income	270			—			270
Distributions to parent	(175		)	—			(175		)
Balance at March 31, 2017	$	10,876		$	(9	)	$	10,867
Balance at December 31, 2017	$	11,368		$	(7	)	$	11,361
Net income	323			—			323
Other comprehensive income	—			1			1
Distributions to parent	(250		)	—			(250		)
Balance at March 31, 2018	$	11,441		$	(6	)	$	11,435

See Notes to Condensed Consolidated Financial Statements

14

PART I

PROGRESS ENERGY, INC.

Condensed Consolidated Statements of Operations and Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018		2017
Operating Revenues	$	2,576	$	2,179
Operating Expenses
Fuel used in electric generation and purchased power	976		726
Operation, maintenance and other	623		560
Depreciation and amortization	384		313
Property and other taxes	123		117
Impairment charges	29		—
Total operating expenses	2,135		1,716
Gains on Sales of Other Assets and Other, net	6		8
Operating Income	447		471
Other Income and Expenses, net	35		40
Interest Expense	209		206
Income Before Income Taxes	273		305
Income Tax Expense	36		104
Net Income	237		201
Less: Net Income Attributable to Noncontrolling Interests	2		2
Net Income Attributable to Parent	$	235	$	199
Net Income	$	237	$	201
Other Comprehensive Income, net of tax
Pension and OPEB adjustments	—		1
Net unrealized gain on cash flow hedges	2		—
Reclassification into earnings from cash flow hedges	—		1
Unrealized gains on available-for-sale securities	—		1
Other Comprehensive Income, net of tax	2		3
Comprehensive Income	239		204
Less: Comprehensive Income Attributable to Noncontrolling Interests	2		2
Comprehensive Income Attributable to Parent	$	237	$	202

See Notes to Condensed Consolidated Financial Statements

15

PART I

PROGRESS ENERGY, INC.

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	20		$	40
Receivables (net of allowance for doubtful accounts of $4 at 2018 and 2017)	122			123
Receivables of VIEs (net of allowance for doubtful accounts of $7 at 2018 and 2017)	815			780
Receivables from affiliated companies	2			31
Notes receivable from affiliated companies	113			240
Inventory	1,537			1,592
Regulatory assets (includes $51 at 2018 and 2017 related to VIEs)	869			741
Other	259			334
Total current assets	3,737			3,881
Property, Plant and Equipment
Cost	47,915			47,323
Accumulated depreciation and amortization	(16,060		)	(15,857		)
Generation facilities to be retired, net	399			421
Net property, plant and equipment	32,254			31,887
Other Noncurrent Assets
Goodwill	3,655			3,655
Regulatory assets (includes $1,082 at 2018 and $1,091 at 2017 related to VIEs)	5,872			6,010
Nuclear decommissioning trust funds	3,290			3,324
Other	990			931
Total other noncurrent assets	13,807			13,920
Total Assets	$	49,798		$	49,688
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	760		$	1,006
Accounts payable to affiliated companies	284			251
Notes payable to affiliated companies	982			805
Taxes accrued	109			101
Interest accrued	213			212
Current maturities of long-term debt (includes $53 at 2018 and 2017 related to VIEs)	1,820			771
Asset retirement obligations	326			295
Regulatory liabilities	272			213
Other	637			729
Total current liabilities	5,403			4,383
Long-Term Debt (includes $1,660 at 2018 and $1,689 at 2017 related to VIEs)	15,787			16,916
Long-Term Debt Payable to Affiliated Companies	150			150
Other Noncurrent Liabilities
Deferred income taxes	3,603			3,502
Asset retirement obligations	5,091			5,119
Regulatory liabilities	5,227			5,306
Accrued pension and other post-retirement benefit costs	527			545
Other	307			302
Total other noncurrent liabilities	14,755			14,774
Commitments and Contingencies
Equity
Common stock, $0.01 par value, 100 shares authorized and outstanding at 2018 and 2017	—			—
Additional paid-in capital	9,142			9,143
Retained earnings	4,591			4,350
Accumulated other comprehensive loss	(29		)	(25		)
Total Progress Energy, Inc. stockholders' equity	13,704			13,468
Noncontrolling interests	(1		)	(3		)
Total equity	13,703			13,465
Total Liabilities and Equity	$	49,798		$	49,688

See Notes to Condensed Consolidated Financial Statements

16

PART I

PROGRESS ENERGY, INC.

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	237		$	201
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	439			365
Equity component of AFUDC	(26		)	(24		)
Gains on sales of other assets	(6		)	(9		)
Impairment charges	29			—
Deferred income taxes	71			220
Accrued pension and other post-retirement benefit costs	6			(3		)
Contributions to qualified pension plans	(45		)	—
Payments for asset retirement obligations	(55		)	(60		)
Other rate case adjustments	37			—
Provision for rate refunds	33			—
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	4			(2		)
Receivables	(33		)	115
Receivables from affiliated companies	29			100
Inventory	55			65
Other current assets	(60		)	(212		)
Increase (decrease) in
Accounts payable	(53		)	(228		)
Accounts payable to affiliated companies	33			(32		)
Taxes accrued	8			12
Other current liabilities	(82		)	(121		)
Other assets	(86		)	(58		)
Other liabilities	(8		)	(14		)
Net cash provided by operating activities	527			315
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(762		)	(1,011		)
Cost of removal, net of salvage	(41		)	—
Purchases of debt and equity securities	(406		)	(629		)
Proceeds from sales and maturities of debt and equity securities	411			635
Notes receivable from affiliated companies	127			(104		)
Other	1			5
Net cash used in investing activities	(670		)	(1,104		)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	—			892
Payments for the redemption of long-term debt	(80		)	(288		)
Notes payable to affiliated companies	177			137
Other	(2		)	(4		)
Net cash provided by financing activities	95			737
Net decrease in cash, cash equivalents and restricted cash	(48		)	(52		)
Cash, cash equivalents and restricted cash at beginning of period	87			110
Cash, cash equivalents and restricted cash at end of period	$	39		$	58
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	316		$	219

See Notes to Condensed Consolidated Financial Statements

17

PART I

PROGRESS ENERGY, INC.

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

						Accumulated Other Comprehensive Loss
									Net Unrealized						Total Progress
	Additional					Net Losses on			Gains on			Pension and			Energy, Inc.
	Paid-in			Retained		Cash Flow			Available-for-			OPEB			Stockholders'			Noncontrolling			Total
(in millions)	Capital			Earnings		Hedges			Sale Securities			Adjustments			Equity			Interests			Equity
Balance at December 31, 2016	$	8,094		$	3,764	$	(23	)	$	1		$	(16	)	$	11,820		$	(13	)	$	11,807
Net income	—			199		—			—			—			199			2			201
Other comprehensive income	—			—		1			1			1			3			—			3
Other	—			—		—			—			—			—			1			1
Balance at March 31, 2017	$	8,094		$	3,963	$	(22	)	$	2		$	(15	)	$	12,022		$	(10	)	$	12,012
Balance at December 31, 2017	$	9,143		$	4,350	$	(18	)	$	5		$	(12	)	$	13,468		$	(3	)	$	13,465
Net income	—			235		—			—			—			235			2			237
Other comprehensive income	—			—		2			—			—			2			—			2
Other(a)	(1		)	6		—			(6		)	—			(1		)	—			(1		)
Balance at March 31, 2018	$	9,142		$	4,591	$	(16	)	$	(1	)	$	(12	)	$	13,704		$	(1	)	$	13,703

(a) Amounts in Retained Earnings and Accumulated Other Comprehensive Loss represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement. See Note 1 for more information.

See Notes to Condensed Consolidated Financial Statements

18

PART I

DUKE ENERGY PROGRESS, LLC

Condensed Consolidated Statements of Operations and Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018		2017
Operating Revenues	$	1,460	$	1,219
Operating Expenses
Fuel used in electric generation and purchased power	509		364
Operation, maintenance and other	381		362
Depreciation and amortization	235		181
Property and other taxes	35		40
Impairment charges	32		—
Total operating expenses	1,192		947
Gains on Sales of Other Assets and Other, net	1		2
Operating Income	269		274
Other Income and Expenses, net	18		31
Interest Expense	81		82
Income Before Income Taxes	206		223
Income Tax Expense	29		76
Net Income and Comprehensive Income	$	177	$	147

See Notes to Condensed Consolidated Financial Statements

19

PART I

DUKE ENERGY PROGRESS, LLC

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	8		$	20
Receivables (net of allowance for doubtful accounts of $2 at 2018 and $1 at 2017)	50			56
Receivables of VIEs (net of allowance for doubtful accounts of $5 at 2018 and 2017)	497			459
Receivables from affiliated companies	5			3
Inventory	1,002			1,017
Regulatory assets	476			352
Other	55			97
Total current assets	2,093			2,004
Property, Plant and Equipment
Cost	29,866			29,583
Accumulated depreciation and amortization	(11,012		)	(10,903		)
Generation facilities to be retired, net	399			421
Net property, plant and equipment	19,253			19,101
Other Noncurrent Assets
Regulatory assets	3,480			3,507
Nuclear decommissioning trust funds	2,568			2,588
Other	641			599
Total other noncurrent assets	6,689			6,694
Total Assets	$	28,035		$	27,799
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	342		$	402
Accounts payable to affiliated companies	208			179
Notes payable to affiliated companies	354			240
Taxes accrued	36			64
Interest accrued	86			102
Current maturities of long-term debt	603			3
Asset retirement obligations	323			295
Regulatory liabilities	184			139
Other	324			376
Total current liabilities	2,460			1,800
Long-Term Debt	6,604			7,204
Long-Term Debt Payable to Affiliated Companies	150			150
Other Noncurrent Liabilities
Deferred income taxes	1,932			1,883
Asset retirement obligations	4,356			4,378
Regulatory liabilities	3,973			3,999
Accrued pension and other post-retirement benefit costs	246			248
Investment tax credits	142			143
Other	46			45
Total other noncurrent liabilities	10,695			10,696
Commitments and Contingencies
Equity
Member's Equity	8,126			7,949
Total Liabilities and Equity	$	28,035		$	27,799

See Notes to Condensed Consolidated Financial Statements

20

PART I

DUKE ENERGY PROGRESS, LLC

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	177		$	147
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization (including amortization of nuclear fuel)	284			228
Equity component of AFUDC	(14		)	(13		)
Gains on sales of other assets	(1		)	(3		)
Impairment charges	32			—
Deferred income taxes	42			120
Accrued pension and other post-retirement benefit costs	4			(5		)
Contributions to qualified pension plans	(25		)	—
Payments for asset retirement obligations	(44		)	(47		)
Other rate case adjustments	37			—
Provision for rate refunds	33			—
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2			(2		)
Receivables	(31		)	65
Receivables from affiliated companies	(2		)	(1		)
Inventory	15			23
Other current assets	(88		)	(60		)
Increase (decrease) in
Accounts payable	(39		)	(192		)
Accounts payable to affiliated companies	29			17
Taxes accrued	(28		)	(68		)
Other current liabilities	(64		)	(81		)
Other assets	18			(44		)
Other liabilities	(5		)	(10		)
Net cash provided by operating activities	332			74
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(424		)	(474		)
Cost of removal, net of salvage	(31		)	(9		)
Purchases of debt and equity securities	(284		)	(476		)
Proceeds from sales and maturities of debt and equity securities	281			470
Notes receivable from affiliated companies	—			165
Other	1			—
Net cash used in investing activities	(457		)	(324		)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	—			(250		)
Notes payable to affiliated companies	114			502
Other	(1		)	(2		)
Net cash provided by financing activities	113			250
Net decrease in cash and cash equivalents	(12		)	—
Cash and cash equivalents at beginning of period	20			11
Cash and cash equivalents at end of period	$	8		$	11
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	137		$	66

See Notes to Condensed Consolidated Financial Statements

21

PART I

DUKE ENERGY PROGRESS, LLC

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

	Member's
(in millions)	Equity
Balance at December 31, 2016	$	7,358
Net income	147
Balance at March 31, 2017	$	7,505
Balance at December 31, 2017	$	7,949
Net income	177
Balance at March 31, 2018	$	8,126

See Notes to Condensed Consolidated Financial Statements

22

PART I

DUKE ENERGY FLORIDA, LLC

Condensed Consolidated Statements of Operations and Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018		2017
Operating Revenues	$	1,115	$	959
Operating Expenses
Fuel used in electric generation and purchased power	467		362
Operation, maintenance and other	237		195
Depreciation and amortization	150		132
Property and other taxes	88		77
Impairment charges	—		1
Total operating expenses	942		767
Operating Income	173		192
Other Income and Expenses, net	21		20
Interest Expense	71		70
Income Before Income Taxes	123		142
Income Tax Expense	20		52
Net Income	$	103	$	90
Other Comprehensive Income, net of tax
Unrealized gains on available-for-sale securities	—		1
Other Comprehensive Income, net of tax	$	—	$	1
Comprehensive Income	$	103	$	91

See Notes to Condensed Consolidated Financial Statements

23

PART I

DUKE ENERGY FLORIDA, LLC

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	6		$	13
Receivables (net of allowance for doubtful accounts of $3 at 2018 and 2017)	71			65
Receivables of VIEs (net of allowance for doubtful accounts of $2 at 2018 and 2017)	318			321
Receivables from affiliated companies	1			2
Notes receivable from affiliated companies	153			313
Inventory	535			574
Regulatory assets (includes $51 at 2018 and 2017 related to VIEs)	393			389
Other (includes $13 at 2018 and $40 at 2017 related to VIEs)	40			86
Total current assets	1,517			1,763
Property, Plant and Equipment
Cost	18,040			17,730
Accumulated depreciation and amortization	(5,042		)	(4,947		)
Net property, plant and equipment	12,998			12,783
Other Noncurrent Assets
Regulatory assets (includes $1,082 at 2018 and $1,091 at 2017 related to VIEs)	2,391			2,503
Nuclear decommissioning trust funds	722			736
Other	301			284
Total other noncurrent assets	3,414			3,523
Total Assets	$	17,929		$	18,069
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	416		$	602
Accounts payable to affiliated companies	82			74
Taxes accrued	72			34
Interest accrued	74			56
Current maturities of long-term debt (includes $53 at 2018 and 2017 related to VIEs)	768			768
Asset Retirement Obligations	3			—
Regulatory liabilities	88			74
Other	299			334
Total current liabilities	1,802			1,942
Long-Term Debt (includes $1,361 at 2018 and $1,389 at 2017 related to VIEs)	6,247			6,327
Other Noncurrent Liabilities
Deferred income taxes	1,812			1,761
Asset retirement obligations	735			742
Regulatory liabilities	1,254			1,307
Accrued pension and other post-retirement benefit costs	248			264
Other	110			108
Total other noncurrent liabilities	4,159			4,182
Commitments and Contingencies
Equity
Member's equity	5,723			5,614
Accumulated other comprehensive (loss) income	(2		)	4
Total equity	5,721			5,618
Total Liabilities and Equity	$	17,929		$	18,069

See Notes to Condensed Consolidated Financial Statements

24

PART I

DUKE ENERGY FLORIDA, LLC

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	103		$	90
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion	152			134
Equity component of AFUDC	(12		)	(11		)
Impairment charges	—			1
Deferred income taxes	29			100
Accrued pension and other post-retirement benefit costs	1			1
Contributions to qualified pension plans	(20		)	—
Payments for asset retirement obligations	(11		)	(14		)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2			—
Receivables	(2		)	51
Receivables from affiliated companies	—			(1		)
Inventory	39			42
Other current assets	42			(72		)
Increase (decrease) in
Accounts payable	(13		)	(35		)
Accounts payable to affiliated companies	8			(48		)
Taxes accrued	38			29
Other current liabilities	(17		)	(47		)
Other assets	(107		)	(13		)
Other liabilities	(5		)	(5		)
Net cash provided by operating activities	227			202
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(338		)	(538		)
Cost of removal, net of salvage	(10		)	9
Purchases of debt and equity securities	(122		)	(153		)
Proceeds from sales and maturities of debt and equity securities	129			165
Notes receivable from affiliated companies	160			(293		)
Other	—			4
Net cash used in investing activities	(181		)	(806		)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	—			892
Payments for the redemption of long-term debt	(80		)	(38		)
Notes payable to affiliated companies	—			(297		)
Other	—			(1		)
Net cash (used in) provided by financing activities	(80		)	556
Net decrease in cash, cash equivalents and restricted cash	(34		)	(48		)
Cash, cash equivalents and restricted cash at beginning of period	53			69
Cash, cash equivalents and restricted cash at end of period	$	19		$	21
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	179		$	153

See Notes to Condensed Consolidated Financial Statements

25

PART I

DUKE ENERGY FLORIDA, LLC

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

			Accumulated
			Other
			Comprehensive
			Income (Loss)
			Net Unrealized
			Gains on
	Member's		Available-for-Sale			Total
(in millions)	Equity		Securities			Equity
Balance at December 31, 2016	$	4,899	$	1		$	4,900
Net income	90		—			90
Other comprehensive income	—		1			1
Balance at March 31, 2017	$	4,989	$	2		$	4,991
Balance at December 31, 2017	$	5,614	$	4		$	5,618
Net income	103		—			103
Other(a)	6		(6		)	—
Balance at March 31, 2018	$	5,723	$	(2	)	$	5,721

(a) Amounts in Member's Equity and Accumulated Other Comprehensive Income (Loss) represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement. See Note 1 for more information.

See Notes to Condensed Consolidated Financial Statements

26

PART I

DUKE ENERGY OHIO, INC.

Condensed Consolidated Statements of Operations and Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
Operating Revenues
Regulated electric	$	336		$	337
Regulated natural gas	174			170
Nonregulated electric and other	14			11
Total operating revenues	524			518
Operating Expenses
Fuel used in electric generation and purchased power – regulated	92			97
Fuel used in electric generation and purchased power – nonregulated	15			15
Cost of natural gas	54			54
Operation, maintenance and other	131			131
Depreciation and amortization	70			67
Property and other taxes	77			72
Total operating expenses	439			436
Loss on Sales of Other Assets and Other, net	(106		)	—
Operating (Loss) Income	(21		)	82
Other Income and Expenses, net	6			5
Interest Expense	22			22
(Loss) Income Before Income Taxes	(37		)	65
Income Tax (Benefit) Expense	(12		)	23
Net (Loss) Income and Comprehensive (Loss) Income	$	(25	)	$	42

See Notes to Condensed Consolidated Financial Statements

27

PART I

DUKE ENERGY OHIO, INC.

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	12		$	12
Receivables (net of allowance for doubtful accounts of $3 at 2018 and 2017)	69			68
Receivables from affiliated companies	77			133
Notes receivable from affiliated companies	—			14
Inventory	108			133
Regulatory assets	43			49
Other	24			39
Total current assets	333			448
Property, Plant and Equipment
Cost	8,892			8,732
Accumulated depreciation and amortization	(2,729		)	(2,691		)
Net property, plant and equipment	6,163			6,041
Other Noncurrent Assets
Goodwill	920			920
Regulatory assets	432			445
Other	48			21
Total other noncurrent assets	1,400			1,386
Total Assets	$	7,896		$	7,875
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	269		$	313
Accounts payable to affiliated companies	72			62
Notes payable to affiliated companies	130			29
Taxes accrued	145			190
Interest accrued	33			21
Current maturities of long-term debt	3			3
Asset retirement obligations	4			3
Regulatory liabilities	53			36
Other	66			71
Total current liabilities	775			728
Long-Term Debt	2,039			2,039
Long-Term Debt Payable to Affiliated Companies	25			25
Other Noncurrent Liabilities
Deferred income taxes	766			781
Asset retirement obligations	79			81
Regulatory liabilities	888			891
Accrued pension and other post-retirement benefit costs	81			59
Other	105			108
Total other noncurrent liabilities	1,919			1,920
Commitments and Contingencies
Equity
Common stock, $8.50 par value, 120 million shares authorized; 90 million shares outstanding at 2018 and 2017	762			762
Additional paid-in capital	2,670			2,670
Accumulated deficit	(294		)	(269		)
Total equity	3,138			3,163
Total Liabilities and Equity	$	7,896		$	7,875

See Notes to Condensed Consolidated Financial Statements

28

PART I

DUKE ENERGY OHIO, INC.

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net (loss) income	$	(25	)	$	42
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	71			68
Equity component of AFUDC	(4		)	(2		)
Losses on sales of other assets	106			—
Deferred income taxes	(15		)	30
Accrued pension and other post-retirement benefit costs	1			1
Payments for asset retirement obligations	(1		)	(2		)
Provision for rate refunds	16			—
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	—			1
Receivables	(1		)	7
Receivables from affiliated companies	56			41
Inventory	25			19
Other current assets	19			9
Increase (decrease) in
Accounts payable	(27		)	(10		)
Accounts payable to affiliated companies	(95		)	1
Taxes accrued	(45		)	(52		)
Other current liabilities	20			9
Other assets	—			(6		)
Other liabilities	(13		)	(3		)
Net cash provided by operating activities	88			153
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(188		)	(143		)
Cost of removal, net of salvage	(14		)	(8		)
Notes receivable from affiliated companies	14			(85		)
Net cash used in investing activities	(188		)	(236		)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	—			93
Payments for the redemption of long-term debt	—			(1		)
Notes payable to affiliated companies	101			(8		)
Other	(1		)	(1		)
Net cash provided by financing activities	100			83
Net increase in cash and cash equivalents	—			—
Cash and cash equivalents at beginning of period	12			13
Cash and cash equivalents at end of period	$	12		$	13
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	64		$	57

See Notes to Condensed Consolidated Financial Statements

29

PART I

DUKE ENERGY OHIO, INC.

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

			Additional
	Common		Paid-in		Accumulated			Total
(in millions)	Stock		Capital		Deficit			Equity
Balance at December 31, 2016	$	762	$	2,695	$	(461	)	$	2,996
Net income	—		—		42			42
Balance at March 31, 2017	$	762	$	2,695	$	(419	)	$	3,038
Balance at December 31, 2017	$	762	$	2,670	$	(269	)	$	3,163
Net loss	—		—		(25		)	(25		)
Balance at March 31, 2018	$	762	$	2,670	$	(294	)	$	3,138

See Notes to Condensed Consolidated Financial Statements

30

PART I

DUKE ENERGY INDIANA, LLC

Condensed Consolidated Statements of Operations and Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018		2017
Operating Revenues	$	731	$	758
Operating Expenses
Fuel used in electric generation and purchased power	232		251
Operation, maintenance and other	181		176
Depreciation and amortization	130		125
Property and other taxes	20		22
Total operating expenses	563		574
Operating Income	168		184
Other Income and Expenses, net	7		10
Interest Expense	40		44
Income Before Income Taxes	135		150
Income Tax Expense	35		59
Net Income and Comprehensive Income	$	100	$	91

See Notes to Condensed Consolidated Financial Statements

31

PART I

DUKE ENERGY INDIANA, LLC

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	15		$	9
Receivables (net of allowance for doubtful accounts of $2 at 2018 and 2017)	56			57
Receivables from affiliated companies	99			125
Inventory	453			450
Regulatory assets	170			165
Other	30			30
Total current assets	823			836
Property, Plant and Equipment
Cost	15,104			14,948
Accumulated depreciation and amortization	(4,759		)	(4,662		)
Net property, plant and equipment	10,345			10,286
Other Noncurrent Assets
Regulatory assets	976			978
Other	234			189
Total other noncurrent assets	1,210			1,167
Total Assets	$	12,378		$	12,289
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	157		$	196
Accounts payable to affiliated companies	73			78
Notes payable to affiliated companies	149			161
Taxes accrued	94			95
Interest accrued	52			57
Current maturities of long-term debt	62			3
Asset retirement obligations	65			54
Regulatory liabilities	20			24
Other	83			104
Total current liabilities	755			772
Long-Term Debt	3,570			3,630
Long-Term Debt Payable to Affiliated Companies	150			150
Other Noncurrent Liabilities
Deferred income taxes	941			925
Asset retirement obligations	713			727
Regulatory liabilities	1,743			1,723
Accrued pension and other post-retirement benefit costs	110			76
Investment tax credits	147			147
Other	28			18
Total other noncurrent liabilities	3,682			3,616
Commitments and Contingencies
Equity
Member's Equity	4,221			4,121
Total Liabilities and Equity	$	12,378		$	12,289

See Notes to Condensed Consolidated Financial Statements

32

PART I

DUKE ENERGY INDIANA, LLC

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	100		$	91
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion	131			126
Equity component of AFUDC	(4		)	(6		)
Deferred income taxes	17			37
Accrued pension and other post-retirement benefit costs	2			1
Contributions to qualified pension plans	(8		)	—
Payments for asset retirement obligations	(11		)	(7		)
Provision for rate refunds	26			—
(Increase) decrease in
Receivables	—			44
Receivables from affiliated companies	26			26
Inventory	(3		)	26
Other current assets	(23		)	(2		)
Increase (decrease) in
Accounts payable	21			(32		)
Accounts payable to affiliated companies	(5		)	1
Taxes accrued	(1		)	41
Other current liabilities	(10		)	(15		)
Other assets	(1		)	(11		)
Other liabilities	—			(3		)
Net cash provided by operating activities	257			317
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(231		)	(189		)
Cost of removal, net of salvage	(7		)	(15		)
Purchases of debt and equity securities	(6		)	(4		)
Proceeds from sales and maturities of debt and equity securities	3			2
Notes receivable from affiliated companies	—			(113		)
Other	3			3
Net cash used in investing activities	(238		)	(316		)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt	—			(2		)
Notes payable to affiliated companies	(12		)	—
Other	(1		)	(1		)
Net cash used in financing activities	(13		)	(3		)
Net increase (decrease) in cash and cash equivalents	6			(2		)
Cash and cash equivalents at beginning of period	9			17
Cash and cash equivalents at end of period	$	15		$	15
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	64		$	84

See Notes to Condensed Consolidated Financial Statements

33

PART I

DUKE ENERGY INDIANA, LLC

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

	Member's
(in millions)	Equity
Balance at December 31, 2016	$	4,067
Net income	91
Balance at March 31, 2017	$	4,158
Balance at December 31, 2017	$	4,121
Net income	100
Balance at March 31, 2018	$	4,221

See Notes to Condensed Consolidated Financial Statements

34

PART I

PIEDMONT NATURAL GAS COMPANY, INC.

Condensed Consolidated Statements of Operations and Comprehensive Income

(Unaudited)

	Three Months Ended
	March 31,
	2018		2017
Operating Revenues	$	553	$	500
Operating Expenses
Cost of natural gas	259		205
Operation, maintenance and other	82		77
Depreciation and amortization	39		35
Property and other taxes	12		13
Total operating expenses	392		330
Operating Income	161		170
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	2		3
Other income and expenses, net	3		—
Total other income and expenses	5		3
Interest Expense	21		20
Income Before Income Taxes	145		153
Income Tax Expense	35		58
Net Income and Comprehensive Income	$	110	$	95

See Notes to Condensed Consolidated Financial Statements

35

PART I

PIEDMONT NATURAL GAS COMPANY, INC.

Condensed Consolidated Balance Sheets

(Unaudited)

(in millions)	March 31, 2018			December 31, 2017
ASSETS
Current Assets
Cash and cash equivalents	$	12		$	19
Receivables (net of allowance for doubtful accounts of $4 at 2018 and $2 at 2017)	251			275
Receivables from affiliated companies	7			7
Inventory	29			66
Regulatory assets	48			95
Other	21			52
Total current assets	368			514
Property, Plant and Equipment
Cost	6,861			6,725
Accumulated depreciation and amortization	(1,500		)	(1,479		)
Net property, plant and equipment	5,361			5,246
Other Noncurrent Assets
Goodwill	49			49
Regulatory assets	274			283
Investments in equity method unconsolidated affiliates	62			61
Other	66			65
Total other noncurrent assets	451			458
Total Assets	$	6,180		$	6,218
LIABILITIES AND EQUITY
Current Liabilities
Accounts payable	$	128		$	125
Accounts payable to affiliated companies	32			13
Notes payable to affiliated companies	107			364
Taxes accrued	65			19
Interest accrued	24			31
Current maturities of long-term debt	250			250
Regulatory liabilities	45			3
Other	55			69
Total current liabilities	706			874
Long-Term Debt	1,787			1,787
Other Noncurrent Liabilities
Deferred income taxes	558			564
Asset retirement obligations	15			15
Regulatory liabilities	1,179			1,141
Accrued pension and other post-retirement benefit costs	4			5
Other	159			170
Total other noncurrent liabilities	1,915			1,895
Commitments and Contingencies
Equity
Common stock, no par value: 100 shares authorized and outstanding at 2018 and 2017	860			860
Retained earnings	912			802
Total equity	1,772			1,662
Total Liabilities and Equity	$	6,180		$	6,218

See Notes to Condensed Consolidated Financial Statements

36

PART I

PIEDMONT NATURAL GAS COMPANY, INC.

Condensed Consolidated Statements of Cash Flows

(Unaudited)

	Three Months Ended
	March 31,
(in millions)	2018			2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$	110		$	95
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	39			37
Deferred income taxes	(7		)	50
Equity in earnings from unconsolidated affiliates	(2		)	(3		)
Accrued pension and other post-retirement benefit costs	(1		)	3
Provision for rate refunds	23			—
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	—			(41		)
Receivables	22			40
Inventory	37			37
Other current assets	79			24
Increase (decrease) in
Accounts payable	(15		)	(31		)
Accounts payable to affiliated companies	19			(5		)
Taxes accrued	46			2
Other current liabilities	18			(17		)
Other assets	4			25
Other liabilities	(1		)	(1		)
Net cash provided by operating activities	371			215
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(121		)	(141		)
Cost of removal, net of salvage	(2		)	(1		)
Contributions to equity method investments	—			(12		)
Other	2			(2		)
Net cash used in investing activities	(121		)	(156		)
CASH FLOWS FROM FINANCING ACTIVITIES
Notes payable and commercial paper	—			(330		)
Notes payable to affiliated companies	(257		)	261
Net cash used in financing activities	(257		)	(69		)
Net decrease in cash and cash equivalents	(7		)	(10		)
Cash and cash equivalents at beginning of period	19			25
Cash and cash equivalents at end of period	$	12		$	15
Supplemental Disclosures:
Significant non-cash transactions:
Accrued capital expenditures	$	52		$	24

See Notes to Condensed Consolidated Financial Statements

37

PART I

PIEDMONT NATURAL GAS COMPANY, INC.

Condensed Consolidated Statements of Changes in Equity

(Unaudited)

	Common		Retained		Total
(in millions)	Stock		Earnings		Equity
Balance at December 31, 2016	$	860	$	812	$	1,672
Net income	—		95		95
Balance at March 31, 2017	$	860	$	907	$	1,767
Balance at December 31, 2017	$	860	$	802	$	1,662
Net income	—		110		110
Balance at March 31, 2018	$	860	$	912	$	1,772

See Notes to Condensed Consolidated Financial Statements

38

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited)

Index to Combined Notes to Condensed Consolidated Financial Statements

The unaudited notes to the condensed consolidated financial statements that follow are a combined presentation. The following list indicates the registrants to which the footnotes apply.

Applicable Notes

Registrant

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

Duke Energy Corporation

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Carolinas, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Progress Energy, Inc.

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Progress, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Florida, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Ohio, Inc.

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Indiana, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Piedmont Natural Gas Company, Inc.

•

•

•

•

•

•

•

•

•

•

•

•

•

Tables within the notes may not sum across due to (i) Progress Energy's consolidation of Duke Energy Progress, Duke Energy Florida and other subsidiaries that are not registrants and (ii) subsidiaries that are not registrants but included in the consolidated Duke Energy balances.

1. ORGANIZATION AND BASIS OF PRESENTATION

NATURE OF OPERATIONS AND BASIS OF CONSOLIDATION

Duke Energy Corporation (collectively with its subsidiaries, Duke Energy) is an energy company headquartered in Charlotte, North Carolina, subject to regulation by the Federal Energy Regulatory Commission (FERC). Duke Energy operates in the United States (U.S.) primarily through its direct and indirect subsidiaries. Certain Duke Energy subsidiaries are also subsidiary registrants, including Duke Energy Carolinas, LLC (Duke Energy Carolinas); Progress Energy, Inc. (Progress Energy); Duke Energy Progress, LLC (Duke Energy Progress); Duke Energy Florida, LLC (Duke Energy Florida); Duke Energy Ohio, Inc. (Duke Energy Ohio), Duke Energy Indiana, LLC (Duke Energy Indiana) and Piedmont Natural Gas Company, Inc. (Piedmont). When discussing Duke Energy’s consolidated financial information, it necessarily includes the results of its separate subsidiary registrants (collectively referred to as the Subsidiary Registrants), which, along with Duke Energy, are collectively referred to as the Duke Energy Registrants.

These Condensed Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries where the respective Duke Energy Registrants have control. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. Substantially all of the Subsidiary Registrants' operations qualify for regulatory accounting.

Duke Energy Carolinas is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Carolinas is subject to the regulatory provisions of the North Carolina Utilities Commission (NCUC), Public Service Commission of South Carolina (PSCSC), U.S. Nuclear Regulatory Commission (NRC) and FERC.

Progress Energy is a public utility holding company headquartered in Raleigh, North Carolina, subject to regulation by FERC. Progress Energy conducts operations through its wholly owned subsidiaries, Duke Energy Progress and Duke Energy Florida.

Duke Energy Progress is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Progress is subject to the regulatory provisions of the NCUC, PSCSC, NRC and FERC.

Duke Energy Florida is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Florida. Duke Energy Florida is subject to the regulatory provisions of the Florida Public Service Commission (FPSC), NRC and FERC.

Duke Energy Ohio is a regulated public utility primarily engaged in the transmission and distribution of electricity in portions of Ohio and Kentucky, the generation and sale of electricity in portions of Kentucky and the transportation and sale of natural gas in portions of Ohio and Kentucky. Duke Energy Ohio conducts competitive auctions for retail electricity supply in Ohio whereby the energy price is recovered from retail customers and recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Operations in Kentucky are conducted through its wholly owned subsidiary, Duke Energy Kentucky, Inc. (Duke Energy Kentucky). References herein to Duke Energy Ohio collectively include Duke Energy Ohio and its subsidiaries, unless otherwise noted. Duke Energy Ohio is subject to the regulatory provisions of the Public Utilities Commission of Ohio (PUCO), Kentucky Public Service Commission (KPSC) and FERC.

Duke Energy Indiana is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Indiana. Duke Energy Indiana is subject to the regulatory provisions of the Indiana Utility Regulatory Commission (IURC) and FERC.

Piedmont is a regulated public utility primarily engaged in the distribution of natural gas in portions of North Carolina, South Carolina and Tennessee. Piedmont is subject to the regulatory provisions of the NCUC, PSCSC, Tennessee Public Utility Commission (TPUC) and FERC.

39

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

BASIS OF PRESENTATION

These Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles (GAAP) in the U.S. for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, these Condensed Consolidated Financial Statements do not include all information and notes required by GAAP in the U.S. for annual financial statements. Since the interim Condensed Consolidated Financial Statements and Notes do not include all information and notes required by GAAP in the U.S. for annual financial statements, the Condensed Consolidated Financial Statements and other information included in this quarterly report should be read in conjunction with the Consolidated Financial Statements and Notes in the Duke Energy Registrants’ combined Annual Report on Form 10-K/A for the year ended December 31, 2017.

The information in these combined notes relates to each of the Duke Energy Registrants as noted in the Index to Combined Notes to Condensed Consolidated Financial Statements. However, none of the registrants make any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself.

These Condensed Consolidated Financial Statements, in the opinion of the respective companies’ management, reflect all normal recurring adjustments necessary to fairly present the financial position and results of operations of each of the Duke Energy Registrants. Amounts reported in Duke Energy’s interim Condensed Consolidated Statements of Operations and each of the Subsidiary Registrants’ interim Condensed Consolidated Statements of Operations and Comprehensive Income are not necessarily indicative of amounts expected for the respective annual periods due to effects of seasonal temperature variations on energy consumption, regulatory rulings, timing of maintenance on electric generating units, changes in mark-to-market valuations, changing commodity prices and other factors.

In preparing financial statements that conform to GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses, and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.

Certain prior year amounts have been reclassified to conform to the current year presentation.

REVENUE

Duke Energy recognizes revenue as customers obtain control of promised goods and services in an amount that reflects consideration expected in exchange for those goods or services. Generally, the delivery of electricity and natural gas results in the transfer of control to customers at the time the commodity is delivered and the amount of revenue recognized is equal to the amount billed to each customer, including estimated volumes delivered when billings have not yet occurred. See Note 12 for further information.

CASH, CASH EQUIVALENTS AND RESTRICTED CASH

Duke Energy, Progress Energy and Duke Energy Florida have restricted cash balances related primarily to collateral assets, escrow deposits and variable interest entities (VIEs). See Note 11 for additional information. Restricted cash amounts are included in Other within Current Assets and Other Noncurrent Assets. The following table presents the components of Cash, cash equivalents and restricted cash included in the Condensed Consolidated Balance Sheets.

	March 31, 2018						December 31, 2017
					Duke						Duke
	Duke		Progress		Energy		Duke		Progress		Energy
	Energy		Energy		Florida		Energy		Energy		Florida
Current Assets
Cash and cash equivalents	$	421	$	20	$	6	$	358	$	40	$	13
Other	149		13		13		138		40		40
Other Noncurrent Assets
Other	9		6		—		9		7		—
Total Cash, cash equivalents and restricted cash	$	579	$	39	$	19	$	505	$	87	$	53

40

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

INVENTORY

Inventory is used for operations and is recorded primarily using the average cost method. Inventory related to regulated operations is valued at historical cost. Inventory related to nonregulated operations is valued at the lower of cost or market. Materials and supplies are recorded as inventory when purchased and subsequently charged to expense or capitalized to property, plant and equipment when installed. Inventory, including excess or obsolete inventory, is written-down to the lower of cost or market value. Once inventory has been written-down, it creates a new cost basis for the inventory that is not subsequently written-up. Provisions for inventory write-offs were not material at March 31, 2018, and December 31, 2017. The components of inventory are presented in the tables below.

	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Materials and supplies	$	2,293	$	763	$	1,095	$	767	$	329	$	82	$	310	$	1
Coal	551		176		221		125		96		13		141		—
Natural gas, oil and other fuel	305		41		221		110		110		13		2		28
Total inventory	$	3,149	$	980	$	1,537	$	1,002	$	535	$	108	$	453	$	29

	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Materials and supplies	$	2,293	$	744	$	1,118	$	774	$	343	$	82	$	309	$	2
Coal	603		192		255		139		116		17		139		—
Natural gas, oil and other fuel	354		35		219		104		115		34		2		64
Total inventory	$	3,250	$	971	$	1,592	$	1,017	$	574	$	133	$	450	$	66

EXCISE TAXES

Certain excise taxes levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis. Otherwise, excise taxes are accounted for on a net basis.

Excise taxes accounted for on a gross basis within both Operating revenues and Property and other taxes on the Condensed Consolidated Statements of Operations were as follows.

	Three Months Ended March 31,
(in millions)	2018		2017
Duke Energy	$	99	$	91
Duke Energy Carolinas	8		9
Progress Energy	54		46
Duke Energy Progress	5		5
Duke Energy Florida	49		41
Duke Energy Ohio	30		28
Duke Energy Indiana	6		7
Piedmont	1		1

NEW ACCOUNTING STANDARDS

The new accounting standards adopted for 2018 and 2017 had no material impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. While immaterial, adoption of the following accounting standards had the most significant impact on the Duke Energy results of operations, cash flows and financial position for the three months endedMarch 31, 2018.

Revenue from Contracts with Customers. In May 2014, the Financial Accounting Standards Board (FASB) issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration expected in exchange for those goods or services. The amendments also required disclosure of sufficient information to allow users to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The majority of Duke Energy’s revenue is in scope of the new guidance. Other revenue arrangements, such as alternative revenue programs and certain purchase power agreements (PPAs) and lighting tariffs accounted for as leases, are excluded from the scope of this guidance and, therefore, are accounted for and evaluated for separate presentation and disclosure under other relevant accounting guidance.

41

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Duke Energy elected the modified retrospective method of adoption effective January 1, 2018. Under the modified retrospective method of adoption, prior year reported results are not restated. Adoption of this standard did not result in a material change in the timing or pattern of revenue recognition and a cumulative-effect adjustment was not recorded at January 1, 2018. Duke Energy utilized certain practical expedients including applying this guidance to open contracts at the date of adoption, expensing costs to obtain a contract where the amortization period of the asset would have been one year or less, ignoring the effects of a significant financing when the period between transfer of the good or service and payment is one year or less and recognizing revenues for certain contracts under the invoice practical expedient, which allows revenue recognition to be consistent with invoiced amounts (including estimated billings) provided certain criteria are met, including consideration of whether the invoiced amounts reasonably represent the value provided to customers.

In preparation for adoption, Duke Energy identified material revenue streams and reviewed representative contracts and tariffs, including those associated with certain long-term customer contracts such as wholesale contracts, PPAs, and other customer arrangements. Duke Energy also monitored the activities of the power and utilities industry revenue recognition task force and has reviewed published positions on specific industry issues to evaluate the impact, if any, on Duke Energy’s specific contracts and conclusions.

Duke Energy applied the available practical expedient to portfolios of tariffs and contracts with similar characteristics. The vast majority of sales, including energy provided to retail customers, are from tariff offerings that provide natural gas or electricity without a defined contractual term ("at-will"). In most circumstances, revenue from contracts with customers is equivalent to the electricity or natural gas supplied and billed in that period (including estimated billings). As such, adoption of the new rules did not result in a shift in the timing or pattern of revenue recognition for such sales. While there have been changes to the captions and descriptions of revenues in Duke Energy’s financial statements, the most significant impact as a result of adopting the standard are additional disclosures around the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. See Note 12 for further information.

Financial Instruments Classification and Measurement. In January 2018, Duke Energy adopted FASB guidance, which revised the classification and measurement of certain financial instruments. The adopted guidance changes the presentation of realized and unrealized gains and losses in certain equity securities that were previously recorded in accumulated other comprehensive income (AOCI). These gains and losses are now recorded in net income. An entity's equity investments that are accounted for under the equity method of accounting are not included within the scope of the new guidance. This guidance had a minimal impact on the Duke Energy Registrant's Condensed Consolidated Statements of Operations and Comprehensive Income as changes in the fair value of most of the Duke Energy Registrants' equity securities are deferred as regulatory assets or liabilities pursuant to accounting guidance for regulated operations. The resulting adjustment of unrealized gains and losses in AOCI to retained earnings was immaterial. The primary impact to Duke Energy as a result of implementing this guidance is adding disclosure requirements to present separately the financial assets and financial liabilities by measurement category and form of financial asset. See Notes 9 and 10 for further information.

Statement of Cash Flows. In November 2016, the FASB issued revised accounting guidance to reduce diversity in practice for the presentation and classification of restricted cash on the Condensed Consolidated Statements of Cash Flows. Under the updated guidance, restricted cash and restricted cash equivalents are included within beginning-of-period and end-of-period cash and cash equivalents on the Condensed Consolidated Statements of Cash Flows. Duke Energy adopted this guidance on January 1, 2018. The guidance has been applied using a retrospective transition method to each period presented. The adoption by Duke Energy of the revised guidance resulted in a change to the amount of Cash, cash equivalents and restricted cash explained when reconciling the beginning-of-period and end-of-period total amounts shown on the Condensed Consolidated Statements of Cash Flows. In addition, a reconciliation has been provided of Cash, cash equivalents and restricted cash reported within the Condensed Consolidated Balance Sheets that sums to the total of the same such amounts in the Condensed Consolidated Statements of Cash Flows. Prior to adoption, the Duke Energy Registrants reflected changes in noncurrent restricted cash within Cash Flows from Investing Activities and changes in current restricted cash within Cash Flows from Operating Activities on the Condensed Consolidated Statement of Cash Flows.

In August 2016, the FASB issued accounting guidance addressing diversity in practice for eight separate cash flow issues. The guidance requires entities to classify distributions received from equity method investees using either the cumulative earnings approach or the nature of the distribution approach. Duke Energy adopted this guidance on January 1, 2018, and has elected the nature of distribution approach. Duke Energy will categorize all distributions received based on legal documentation describing the nature of the activities generating the distribution. Cash inflows resulting in a return on investment (surplus) will be reflected in Cash Flows from Operating Activities on the Condensed Consolidated Statements of Cash Flows, whereas cash inflows resulting in a return of investment (capital) will be reflected in Cash Flows from Investing Activities on the Condensed Consolidated Statements of Cash Flows. The guidance has been applied using the retrospective transition method to each period presented. There are no changes to the Condensed Consolidated Statements of Cash Flows for the periods presented as a result of this accounting change.

Retirement Benefits. In March 2017, the FASB issued revised accounting guidance for the presentation of net periodic costs related to benefit plans. Previous guidance required the aggregation of all the components of net periodic costs on the Condensed Consolidated Statement of Operations and did not require the disclosure of the location of net periodic costs on the Condensed Consolidated Statement of Operations. Under the amended guidance, the service cost component of net periodic costs is included within Operating Income within the same line as other compensation expenses. All other components of net periodic costs are outside of Operating Income. In addition, the updated guidance permits only the service cost component of net periodic costs to be capitalized to Inventory or Property, Plant and Equipment. This represents a change from previous guidance, which permitted all components of net periodic costs to be eligible for capitalization.

Duke Energy adopted this guidance on January 1, 2018. Under previous guidance, Duke Energy presented the total non-capitalized net periodic costs within Operation, maintenance and other on the Condensed Consolidated Statement of Operations. The adoption of this guidance resulted in a retrospective change to reclassify the presentation of the non-service cost (benefit) components of net periodic costs to Other income and expenses. Duke Energy utilized the practical expedient for retrospective presentation. The change in components of net periodic costs eligible for capitalization is applicable prospectively. Since Duke Energy’s service cost component is greater than the total net periodic costs, the change results in increased capitalization of net periodic costs, higher Operation, maintenance and other and higher Other income and expenses. The resulting prospective impact to Duke Energy is an immaterial increase in Net Income. See Note 15 for further information.

42

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

For Duke Energy, the retrospective change resulted in higher Operation, maintenance and other and higher Other income and expenses, net, of $156 million, $131 million and $96 million for the years ended December 31, 2017, 2016 and 2015, respectively. There was no change to Net Income for these prior periods.

The following new Accounting Standards Updates (ASUs) have been issued, but have not yet been adopted by Duke Energy, as of March 31, 2018.

Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet.

For Duke Energy, this guidance is effective for interim and annual periods beginning January 1, 2019. The guidance will be applied using a modified retrospective approach. Upon adoption, Duke Energy expects to elect certain of the practical expedients upon adoption:

Practical Expedient	Description
Package of transition practical expedients (for leases commenced prior to adoption date and must be adopted as a package)	Do not need to reassess whether any expired or existing contracts are/or contain leases, do not need to reassess the lease classification for any expired or existing leases and do not need to reassess initial direct costs for any existing leases.
Short-term lease expedient (elect by class of underlying asset)	Elect as an accounting policy to not apply the recognition requirements to short-term leases by asset class.
Lease and non-lease components (elect by class of underlying asset)	Duke Energy will likely elect as an accounting policy to not separate non-lease components from lease components and instead account for each lease and associated non-lease component as a single lease component.
Hindsight expedient (when determining lease term)	Elect to use hindsight to determine the lease term.
Easement expedient	Elect to carry forward current accounting treatment for existing easements.

Duke Energy is currently evaluating the financial statement impact of adopting this standard and is continuing to monitor industry implementation issues, including pipeline laterals, pole attachments and renewable PPAs. Other than an expected increase in assets and liabilities, the ultimate impact of the new standard has not yet been determined. Significant system enhancements, including additional processes and controls, will be required to facilitate the identification, tracking and reporting of potential leases based upon requirements of the new lease standard. Duke Energy has begun the implementation of a third-party software tool to help with the adoption and ongoing accounting under the new standard.

2. BUSINESS SEGMENTS

Operating segments are determined based on information used by the chief operating decision-maker in deciding how to allocate resources and evaluate the performance of the business. Duke Energy evaluates segment performance based on segment income. Segment income is defined as income from continuing operations net of income attributable to noncontrolling interests. Segment income includes intercompany revenues and expenses that are eliminated on the Condensed Consolidated Financial Statements. Certain governance costs are allocated to each segment. In addition, direct interest expense and income taxes are included in segment income.

Duke Energy

Duke Energy's segment structure includes the following segments: Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables.

The Electric Utilities and Infrastructure segment includes Duke Energy's regulated electric utilities in the Carolinas, Florida and the Midwest. The regulated electric utilities conduct operations through the Subsidiary Registrants that are substantially all regulated and, accordingly, qualify for regulatory accounting treatment. Electric Utilities and Infrastructure also includes Duke Energy's electric transmission infrastructure investments.

The Gas Utilities and Infrastructure segment includes Piedmont, Duke Energy's natural gas local distribution companies in Ohio and Kentucky, and Duke Energy's natural gas storage and midstream pipeline investments. Gas Utilities and Infrastructure's operations are substantially all regulated and, accordingly, qualify for regulatory accounting treatment.

Commercial Renewables is primarily comprised of nonregulated utility scale wind and solar generation assets located throughout the U.S.

The remainder of Duke Energy’s operations is presented as Other, which is primarily comprised of interest expense on holding company debt, unallocated corporate costs and Duke Energy’s wholly owned captive insurance company, Bison Insurance Company Limited (Bison). Other also includes Duke Energy's 17.5 percent interest in National Methanol Company (NMC), a large regional producer of methyl tertiary butyl ether located in Saudi Arabia. The investment in NMC is accounted for under the equity method of accounting.

43

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Business segment information is presented in the following tables. Segment assets presented exclude intercompany assets.

	Three Months Ended March 31, 2018
	Electric		Gas				Total
	Utilities and		Utilities and		Commercial		Reportable
(in millions)	Infrastructure		Infrastructure		Renewables		Segments		Other			Eliminations			Consolidated
Unaffiliated revenues	$	5,315	$	702	$	101	$	6,118	$	17		$	—		$	6,135
Intersegment revenues	8		25		—		33		18			(51		)	—
Total revenues	$	5,323	$	727	$	101	$	6,151	$	35		$	(51	)	$	6,135
Segment income (loss)(a)(b)(c)	$	750	$	116	$	20	$	886	$	(266	)	$	—		$	620
Add back noncontrolling interests															2
Net income															$	622
Segment assets	$	120,021	$	11,396	$	4,265	$	135,682	$	2,682		$	177		$	138,541

	Three Months Ended March 31, 2017
	Electric		Gas				Total
	Utilities and		Utilities and		Commercial		Reportable
(in millions)	Infrastructure		Infrastructure		Renewables		Segments		Other			Eliminations			Consolidated
Unaffiliated revenues	$	4,939	$	648	$	128	$	5,715	$	14		$	—		$	5,729
Intersegment revenues	8		22		—		30		19			(49		)	—
Total revenues	$	4,947	$	670	$	128	$	5,745	$	33		$	(49	)	$	5,729
Segment income (loss)	$	635	$	133	$	25	$	793	$	(77	)	$	—		$	716
Add back noncontrolling interests															1
Net income															$	717

(a) Electric Utilities and Infrastructure includes regulatory charges related to NCUC orders and settlements. See Note 3 for additional information.

(b) Gas Utilities and Infrastructure includes an impairment of the investment in Constitution Pipeline Company, LLC (Constitution). See Note 3 for additional information.

(c) Other includes the loss on the sale of the retired Beckjord generating station (Beckjord) described below and a valuation allowance recorded against the alternative minimum tax credits subject to sequestration. See Note 16 for additional information on the valuation allowance.

Beckjord, a nonregulated facility retired during 2014, was sold on February 26, 2018, at a pretax loss of $106 million recorded within (Loss) Gains on Sales of Other Assets and Other, net and $1 million recorded within Operation, maintenance and other on Duke Energy's Condensed Consolidated Statements of Operations. The sale included the transfer of coal ash basins and other real property and indemnification from any and all potential future claims related to the property, whether arising under environmental laws or otherwise.

Duke Energy Ohio

Duke Energy Ohio has two reportable operating segments, Electric Utilities and Infrastructure and Gas Utilities and Infrastructure.

Electric Utilities and Infrastructure transmits and distributes electricity in portions of Ohio and generates, distributes and sells electricity in portions of Northern Kentucky. Gas Utilities and Infrastructure transports and sells natural gas in portions of Ohio and Northern Kentucky. It conducts operations primarily through Duke Energy Ohio and its wholly owned subsidiary, Duke Energy Kentucky.

44

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The remainder of Duke Energy Ohio's operations is presented as Other, which is primarily comprised of governance costs allocated by its parent, Duke Energy, and revenues and expenses related to Duke Energy Ohio's contractual arrangement to buy power from the Ohio Valley Electric Corporation's (OVEC) power plants. See Note 7 for additional information on related party transactions.

	Three Months Ended March 31, 2018
	Electric		Gas		Total
	Utilities and		Utilities and		Reportable
(in millions)	Infrastructure		Infrastructure		Segments		Other			Eliminations			Consolidated
Total revenues	$	336	$	174	$	510	$	14		$	—		$	524
Segment income (loss)/Net income (loss)(a)	33		34		67		(92		)	—			(25		)
Segment assets	$	5,165	$	2,709	$	7,874	$	25		$	(3	)	$	7,896

	Three Months Ended March 31, 2017
	Electric		Gas		Total
	Utilities and		Utilities and		Reportable
(in millions)	Infrastructure		Infrastructure		Segments		Other			Consolidated
Total revenues	$	337	$	170	$	507	$	11		$	518
Segment income (loss)/Net income (loss)	24		26		50		(8		)	42

(a) Other includes the loss on the sale of the retired Beckjord generating station described above.

3. REGULATORY MATTERS

RATE-RELATED INFORMATION

The NCUC, PSCSC, FPSC, IURC, PUCO, TPUC and KPSC approve rates for retail electric and natural gas services within their states. The FERC approves rates for electric sales to wholesale customers served under cost-based rates (excluding Ohio and Indiana), as well as sales of transmission service. The FERC also regulates certification and siting of new interstate natural gas pipeline projects.

Duke Energy Carolinas and Duke Energy Progress

Ash Basin Closure Costs Deferral – North Carolina

On December 30, 2016, Duke Energy Carolinas and Duke Energy Progress filed a joint petition with the NCUC seeking an accounting order authorizing deferral of certain costs incurred in connection with federal and state environmental remediation requirements related to the permanent closure of ash basins and other ash storage units at coal-fired generating facilities that have provided or are providing generation to customers located in North Carolina. Initial comments were received in March 2017, and reply comments were filed on April 19, 2017. The NCUC has consolidated Duke Energy Carolinas' and Duke Energy Progress’ coal ash deferral requests into their respective general rate case dockets for decision. See "2017 North Carolina Rate Case" sections below for additional discussion. Duke Energy Carolinas is still awaiting an order in its case and, as such, cannot predict the outcome of this matter.

Duke Energy Carolinas

2017 North Carolina Rate Case

On August 25, 2017, Duke Energy Carolinas filed an application with the NCUC for a rate increase for retail customers of approximately $647 million, which represents an approximate 13.6 percent increase in annual base revenues. The rate increase is driven by capital investments subsequent to the previous base rate case, including the William States Lee Combined Cycle Facility discussed below, grid improvement projects, AMI, investments in customer service technologies, costs of complying with coal combustion residuals (CCR) regulations and the North Carolina Coal Ash Management Act of 2014 (Coal Ash Act) and recovery of costs related to licensing and development of the William States Lee III Nuclear Station (Lee Nuclear Station) discussed below. On February 28, 2018, Duke Energy Carolinas and the North Carolina Public Staff filed an Agreement and Stipulation of Partial Settlement resolving certain portions of the proceeding, pending NCUC approval. Terms of the settlement include a return on equity of 9.9 percent and a capital structure of 52 percent equity and 48 percent debt. As a result of the settlement, Duke Energy Carolinas recorded a pretax charge of approximately $4 million to Operations, maintenance and other on the Condensed Consolidated Statements of Operations. The settlement does not include agreement on portions of the rate case relating to recovery of costs for Lee Nuclear Station and coal ash basin deferred costs, a rider for recovery of grid improvement projects or the manner in which the Federal Tax Cut and Jobs Act (Tax Act) should be addressed in this case, which will be decided by the NCUC separately. Taking into consideration the settled portions and Duke Energy Carolinas’ requested recovery of the non-settled portions, the requested base rate increase is reduced to approximately $472 million. The evidentiary hearing for this matter concluded on March 22, 2018, and a decision and revised customer rates are expected by mid–2018. Duke Energy Carolinas cannot predict the outcome of this matter.

45

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

FERC Formula Rate Matter

On July 31, 2017, Piedmont Municipal Power Agency (PMPA) filed a complaint with FERC against Duke Energy Carolinas alleging that Duke Energy Carolinas misapplied the formula rate under the PPA between the parties by including in its rates amortization expense associated with regulatory assets and recorded in a certain account without FERC approval. Duke Energy Carolinas disagreed with PMPA as it believed it was properly applying its FERC filed rate. On February 15, 2018, FERC issued an order ruling in favor of PMPA and ordered Duke Energy Carolinas to refund to PMPA all amounts improperly collected under the PPA. Duke Energy Carolinas has issued to PMPA and similarly situated wholesale customers refunds of approximately $25 million.

William States Lee Combined Cycle Facility

On April 9, 2014, the PSCSC granted Duke Energy Carolinas and North Carolina Electric Membership Corporation (NCEMC) a Certificate of Environmental Compatibility and Public Convenience and Necessity for the construction and operation of a 750-megawatt (MW) combined-cycle natural gas-fired generating plant at Duke Energy Carolinas' existing William States Lee Generating Station in Anderson, South Carolina. Duke Energy Carolinas began construction in July 2015 and its share of the cost to build the facility was approximately $650 million, including allowance for funds used during construction (AFUDC). The project commenced commercial operation on April 5, 2018. NCEMC will own approximately 13 percent of the project.

Lee Nuclear Station

In December 2007, Duke Energy Carolinas applied to the NRC for combined operating licenses (COLs) for two Westinghouse Electric Company (Westinghouse) AP1000 reactors for the proposed William States Lee III Nuclear Station to be located at a site in Cherokee County, South Carolina. The NCUC and PSCSC concurred with the prudency of Duke Energy Carolinas incurring certain project development and preconstruction costs through several separately issued orders, although full cost recovery is not guaranteed. In December 2016, the NRC issued a COL for each reactor. Duke Energy Carolinas is not required to build the nuclear reactors as a result of the COLs being issued.

On March 29, 2017, Westinghouse filed for voluntary Chapter 11 bankruptcy in the U.S. Bankruptcy Court for the Southern District of New York. As part of its 2017 North Carolina Rate Case discussed above, Duke Energy Carolinas is seeking NCUC approval to cancel the development of the Lee Nuclear Station project due to the Westinghouse bankruptcy filing and other market activity and is requesting recovery of incurred licensing and development costs. Duke Energy Carolinas will maintain the license issued by the NRC in December 2016 as an option for potential future development. AFUDC was suspended effective January 1, 2018, as currently only immaterial costs to maintain the license are being incurred. As of March 31, 2018, Duke Energy Carolinas has incurred approximately $558 million of costs, including AFUDC, related to the project. These project costs are included in Net property, plant and equipment on Duke Energy Carolinas’ Condensed Consolidated Balance Sheets. Duke Energy Carolinas cannot predict the outcome of this matter.

Duke Energy Progress

2017 North Carolina Rate Case

On June 1, 2017, Duke Energy Progress filed an application with the NCUC for a rate increase for retail customers of approximately $477 million, which represented an approximate 14.9 percent increase in annual base revenues. Subsequent to the filing, Duke Energy Progress adjusted the requested amount to $420 million, representing an approximate 13 percent increase. The rate increase is driven by capital investments subsequent to the previous base rate case, costs of complying with CCR regulations and the Coal Ash Act, costs relating to storm recovery, investments in customer service technologies and recovery of costs associated with renewable purchased power.

On December 16, 2016, Duke Energy Progress filed a petition with the NCUC requesting an accounting order to defer certain costs incurred in connection with response to Hurricane Matthew and other significant storms in 2016. The final estimate of incremental operation and maintenance and capital costs of $116 million was filed with the NCUC in September 2017. On July 10, 2017, the NCUC consolidated Duke Energy Progress' storm deferral request into the Duke Energy Progress rate case docket for decision.

On November 22, 2017, Duke Energy Progress and the North Carolina Public Staff filed an Agreement and Stipulation of Partial Settlement resolving certain portions of the proceeding. Terms of the settlement included a return on equity of 9.9 percent and a capital structure of 52 percent equity and 48 percent debt. As a result of the settlement, in 2017 Duke Energy Progress recorded pretax charges totaling approximately $25 million to Impairment charges and Operation, maintenance and other on the Condensed Consolidated Statements of Operations, principally related to disallowances from rate base of certain projects at the Mayo and Sutton plants. On February 23, 2018, the NCUC issued an order approving the stipulation. The order also included the following material components not covered in the stipulation:

• recovery of the remaining $234 million of deferred coal ash basin closure costs over a five-year period with a return at Duke Energy Progress' weighted average cost of capital, excluding $9.5 million of retail deferred coal ash basin costs related to ash hauling at Duke Energy Progress' Asheville Plant;

• assessment of a $30 million management penalty ratably over a five-year period by reducing the annual recovery of the deferred coal ash costs;

• denial of Duke Energy Progress' request for recovery of future estimated ongoing annual coal ash costs of $129 million with approval to defer such costs with a return at Duke Energy Progress' weighted average cost of capital, to be considered for recovery in the next rate case;

• and approval to recover $51 million of the approximately $80 million deferred storm costs over a five-year period with amortization beginning in October 2016. The order did not allow the deferral of the associated capital costs or a return on the deferred balance during the deferral period.

46

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The order also impacted certain amounts that were similarly recorded on Duke Energy Carolinas' Condensed Consolidated Balance Sheets. As a result of the order, Duke Energy Progress and Duke Energy Carolinas recorded pretax charges of $68 million and $14 million, respectively, in the first quarter of 2018 to Impairment charges, Operation, maintenance and other and Interest Expense on the Condensed Consolidated Statements of Operations. These charges primarily related to the coal ash basin disallowance and management penalty and deferred storm cost adjustments. Revised customer rates became effective on March 16, 2018.

South Carolina Rate Case

In December 2016, the PSCSC approved a rate case settlement agreement among the Office of Regulatory Staff, intervenors and Duke Energy Progress. Terms of the settlement agreement included an approximate $56 million increase in revenues over a two-year period. An increase of approximately $38 million in revenues was effective January 1, 2017, and an additional increase of approximately $18.5 million in revenues was effective January 1, 2018. Duke Energy Progress amortized approximately $18.5 million from the cost of removal reserve in 2017. Other settlement terms included a rate of return on equity of 10.1 percent, recovery of coal ash costs incurred from January 1, 2015, through June 30, 2016, over a 15‑year period and ongoing deferral of allocated ash basin closure costs from July 1, 2016, until the next base rate case. The settlement also provides that Duke Energy Progress will not seek an increase in rates in South Carolina to occur prior to 2019, with limited exceptions.

Western Carolinas Modernization Plan

On November 4, 2015, Duke Energy Progress announced a Western Carolinas Modernization Plan, which included retirement of the existing Asheville coal-fired plant, the construction of two 280‑MW combined-cycle natural gas plants having dual-fuel capability, with the option to build a third natural gas simple cycle unit in 2023 based upon the outcome of initiatives to reduce the region's power demand. The plan also included upgrades to existing transmission lines and substations, installation of solar generation and a pilot battery storage project. These investments will be made within the next seven years. Duke Energy Progress is also working with the local natural gas distribution company to upgrade an existing natural gas pipeline to serve the natural gas plant.

On March 28, 2016, the NCUC issued an order approving a CPCN for the new combined-cycle natural gas plants, but denying the CPCN for the contingent simple cycle unit without prejudice to Duke Energy Progress to refile for approval in the future. On March 28, 2018, Duke Energy Progress filed an annual progress report for the construction of the combined-cycle plants with the NCUC, with an estimated cost of $893 million. Site preparation activities for the combined-cycle plants are complete and construction of these plants began in 2017, with an expected in-service date in late 2019. Duke Energy Progress plans to file for future approvals related to the proposed solar generation and pilot battery storage project.

The carrying value of the 376-MW Asheville coal-fired plant, including associated ash basin closure costs, of $365 million and $385 million is included in Generation facilities to be retired, net on Duke Energy Progress' Condensed Consolidated Balance Sheets as of March 31, 2018, and December 31, 2017, respectively. Duke Energy Progress' request for a regulatory asset at the time of retirement with amortization over a 10-year period was approved by the NCUC on February 23, 2018.

Shearon Harris Nuclear Plant Expansion

In 2006, Duke Energy Progress selected a site at Harris to evaluate for possible future nuclear expansion. On February 19, 2008, Duke Energy Progress filed its COL application with the NRC for two Westinghouse AP1000 reactors at Harris, which the NRC docketed for review. On May 2, 2013, Duke Energy Progress filed a letter with the NRC requesting the NRC to suspend its review activities associated with the COL at the Harris site. The NCUC and PSCSC approved deferral of retail costs. Total deferred costs were approximately $47 million as of December 31, 2017, and are recorded in Regulatory assets on Duke Energy Progress’ Condensed Consolidated Balance Sheets. On November 17, 2016, the FERC approved Duke Energy Progress’ rate recovery request filing for the wholesale ratepayers’ share of the abandonment costs, including a debt only return to be recovered through revised formula rates and amortized over a 15-year period beginning May 1, 2014. As part of the settlement agreement for the 2017 North Carolina Rate Case discussed above, Duke Energy Progress will amortize the regulatory asset over an eight-year period. NCUC approved the settlement on February 23, 2018.

Duke Energy Florida

Storm Restoration Cost Recovery

In September 2017, Duke Energy Florida’s service territory suffered significant damage from Hurricane Irma, resulting in approximately 1.3 million customers experiencing outages. In the fourth quarter of 2017, Duke Energy Florida also incurred preparation costs related to Hurricane Nate. On December 28, 2017, Duke Energy Florida filed a petition with the FPSC to recover incremental storm restoration costs for hurricanes Irma and Nate and to replenish the storm reserve. The estimated recovery amount is approximately $513 million, which includes reestablishment of a $132 million storm reserve. On February 6, 2018, the FPSC approved a stipulation that would apply tax savings resulting from the Tax Act toward storm costs effective January 2018 in lieu of implementing a storm surcharge. Storm costs are currently expected to be fully recovered by approximately mid-2021. The evidentiary hearing in this matter is scheduled for the week of October 15, 2018. At March 31, 2018, Duke Energy Florida's Condensed Consolidated Balance Sheets included approximately $338 million of recoverable costs under the FPSC's storm rule in Regulatory assets within Current Assets and Other Noncurrent Assets related to storm recovery.

47

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Citrus County Combined Cycle Facility

On October 2, 2014, the FPSC granted Duke Energy Florida a Determination of Need for the construction of a 1,640-MW combined-cycle natural gas plant in Citrus County, Florida. On May 5, 2015, the Florida Department of Environmental Protection approved Duke Energy Florida's Site Certification Application. The project has received all required permits and approvals and construction began in October 2015. The facility is expected to be commercially available by the end of 2018 at an estimated cost of $1.5 billion, including AFUDC. On April 2, 2018, Duke Energy Florida filed a petition seeking approval to include in base rates the revenue requirements associated with the new facility. The annual retail revenue requirement is approximately $200 million. The plant will receive natural gas from the Sabal Trail Transmission, LLC (Sabal Trail) pipeline discussed below.

Duke Energy Ohio

2017 Electric Security Plan Filing

On June 1, 2017, Duke Energy Ohio filed with the PUCO a request for a standard service offer in the form of an electric security plan (ESP). If approved by the PUCO, the term of the ESP would be from June 1, 2018, to May 31, 2024. Terms of the ESP include continuation of market-based customer rates through competitive procurement processes for generation, continuation and expansion of existing rider mechanisms and proposed new rider mechanisms relating to regulatory mandates, costs incurred to enhance the customer experience and transform the grid and a service reliability rider for vegetation management. On February 15, 2018, the procedural schedule was suspended to facilitate ongoing settlement discussions. On April 13, 2018, Duke Energy Ohio filed a Motion to consolidate this proceeding with several other cases currently pending before the Commission, including, but not limited to, its Electric Base Rate Case. Additionally, on April 13, 2018, Duke Energy Ohio, along with certain intervenors, filed a Stipulation and Recommendation (Stipulation) with the PUCO resolving certain issues in this proceeding. The Stipulation establishes a regulatory model for the next seven years via the approval of the ESP and continues the current model for procuring supply for non-shopping customers, including recovery mechanisms. The Stipulation is subject to the review and approval of PUCO. An evidentiary hearing to review the Stipulation and other issues in the cases will be scheduled at a later date. Duke Energy Ohio cannot predict the outcome of this matter.

Electric Base Rate Case

Duke Energy Ohio filed with the PUCO an electric distribution base rate case application and supporting testimony in March 2017. Duke Energy Ohio has requested an estimated annual increase of approximately $15 million and a return on equity of 10.4 percent. The application also includes requests to continue certain current riders and establish new riders. On September 26, 2017, the PUCO staff filed a report recommending a revenue decrease between approximately $18 million and $29 million and a return on equity between 9.22 percent and 10.24 percent. On February 15, 2018, the procedural schedule was suspended to facilitate ongoing settlement discussions. On April 13, 2018, Duke Energy Ohio filed a Motion to consolidate this proceeding with several other cases currently pending before the Commission. On April 13, 2018, Duke Energy Ohio, along with certain intervenors, filed the Stipulation with the PUCO resolving certain issues in this proceeding. Major components of the Stipulation include a $19 million annual base distribution rate decrease with a return on equity of 9.84 percent based upon a capital structure of 50.75 percent equity and 49.25 percent debt. Upon approval of new rates, Duke Energy Ohio's rider for recovering its initial SmartGrid implementation ends as the costs will be recovered through base rates. The Stipulation also renews 14 existing riders, some of which were included in the Company's ESP, and two new riders including the Enhanced Service Reliability Rider to recover vegetation management costs not included in base rates, up to $10 million per year (operation and maintenance only) and the Power Forward Rider to recover costs incurred to enhance the customer experience and further transform the grid (operation and maintenance and capital). The Stipulation is subject to the review and approval of PUCO. An evidentiary hearing to review the Stipulation and other issues in the cases will be scheduled at a later date. Duke Energy Ohio has requested new rates go into effect June 1, 2018. In addition to the changes in revenue attributable to the Stipulation, Duke Energy Ohio’s capital-related riders, including the Distribution Capital Investments Rider, will begin to reflect the lower federal income tax rate associated with the Tax Act beginning with updates to be reflected in customers’ bills beginning April 1, 2018. At that time, all impacts of the lower federal income tax rate will be incorporated into customer rates, resulting in lower electric revenue of approximately $20 million on an annualized basis. All other implications of the Tax Act, including the quantification and timing of any refunds associated with excess accumulated deferred income taxes, will be deferred to PUCO’s open investigation, which is pending. Duke Energy Ohio cannot predict the outcome of this matter.

Ohio Valley Electric Corporation

On March 31, 2017, Duke Energy Ohio filed for approval to adjust its existing price stabilization rider (Rider PSR), which is currently set at zero dollars, to pass through net costs related to its contractual entitlement to capacity and energy from the generating assets owned by OVEC. Duke Energy Ohio is seeking deferral authority for net costs incurred from January 1, 2018, until the new rates under Rider PSR are put into effect. Various intervenors have filed motions to dismiss or stay the proceeding and Duke Energy Ohio has opposed these filings. On April 13, 2018, Duke Energy Ohio filed a Motion to consolidate this proceeding with several other cases currently pending before the Commission. Also on April 13, 2018, Duke Energy Ohio, along with certain intervenors, filed a Stipulation with the PUCO resolving certain issues in this proceeding. The Stipulation, if approved, would activate Rider PSR for recovery of net costs incurred since January 1, 2018. The Stipulation is subject to the review and approval of PUCO. An evidentiary hearing to review the Stipulation and other issues in the cases will be scheduled at a later date. See Note 11 for additional discussion of Duke Energy Ohio's ownership interest in OVEC. Duke Energy Ohio cannot predict the outcome of this matter.

48

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Energy Efficiency Cost Recovery

On March 28, 2014, Duke Energy Ohio filed an application for recovery of program costs, lost distribution revenue and performance incentives related to its energy efficiency and peak demand reduction programs. These programs are undertaken to comply with environmental mandates set forth in Ohio law. The PUCO approved Duke Energy Ohio’s application but found that Duke Energy Ohio was not permitted to use banked energy savings from previous years in order to calculate the amount of allowed incentive. This conclusion represented a change to the cost recovery mechanism that had been agreed upon by intervenors and approved by the PUCO in previous cases. The PUCO granted the applications for rehearing filed by Duke Energy Ohio and an intervenor. On January 6, 2016, Duke Energy Ohio and the PUCO Staff entered into a stipulation, pending the PUCO's approval, to resolve issues related to performance incentives and the PUCO Staff audit of 2013 costs, among other issues. In December 2015, based upon the stipulation, Duke Energy Ohio re-established approximately $20 million of the revenues that had been previously reversed. On October 26, 2016, the PUCO issued an order approving the stipulation without modification. In December 2016, the PUCO granted the intervenors request for rehearing for the purpose of further review. Duke Energy Ohio cannot predict the outcome of this matter.

On June 15, 2016, Duke Energy Ohio filed an application for approval of a three-year energy efficiency and peak demand reduction portfolio of programs. A stipulation and modified stipulation were filed on December 22, 2016, and January 27, 2017, respectively. Under the terms of the stipulations, which included support for deferral authority of all costs and a cap on shared savings incentives, Duke Energy Ohio has offered its energy efficiency and peak demand reduction programs throughout 2017. On February 3, 2017, Duke Energy Ohio filed for deferral authority of its costs incurred in 2017 in respect of its proposed energy efficiency and peak demand reduction portfolio. On September 27, 2017, the PUCO issued an order approving a modified stipulation. The modifications impose an annual cap of approximately $38 million on program costs and shared savings incentives combined, but allowed for Duke Energy Ohio to file for a waiver of costs in excess of the cap in 2017. The PUCO approved the waiver request up to a total cost of $56 million. On November 21, 2017, the PUCO granted Duke Energy Ohio's and intervenor's applications for rehearing of the September 27, 2017, order. On January 10, 2018, the PUCO denied the Ohio Consumers' Counsel’s application for rehearing of the PUCO order granting Duke Energy Ohio's waiver request. Duke Energy Ohio cannot predict the outcome of this matter.

2014 Electric Security Plan

In April 2015, the PUCO modified and approved Duke Energy Ohio's proposed ESP, with a three-year term and an effective date of June 1, 2015. The PUCO approved a competitive procurement process for SSO load, a distribution capital investment rider and a tracking mechanism for incremental distribution expenses caused by major storms. The PUCO also approved a placeholder tariff for a price stabilization rider, but denied Duke Energy Ohio's specific request to include Duke Energy Ohio's entitlement to generation from OVEC in the rider at this time; however, the order allows Duke Energy Ohio to submit additional information to request recovery in the future. On May 4, 2015, Duke Energy Ohio filed an application for rehearing requesting the PUCO to modify or amend certain aspects of the order. On May 28, 2015, the PUCO granted all applications for rehearing filed in the case for future consideration. On March 21, 2018, the PUCO issued an order denying the Company's issues on rehearing. On April 20, 2018, Duke Energy Ohio filed a second application for rehearing based upon the Commission’s March 21, 2018, Order.

Natural Gas Pipeline Extension

Duke Energy Ohio is proposing to install a new natural gas pipeline (the Central Corridor Project) in its Ohio service territory to increase system reliability and enable the retirement of older infrastructure. The pipeline is expected to cost approximately $112 million, excluding AFUDC. On January 20, 2017, Duke Energy Ohio filed an amended application with the Ohio Power Siting Board (OPSB) for approval of one of two proposed routes. A public hearing was held on June 15, 2017, and an adjudicatory hearing was scheduled to begin September 11, 2017. On August 24, 2017, an administrative law judge (ALJ) granted a request made by Duke Energy Ohio to delay the procedural schedule while it works through various issues related to the pipeline route. In April 2018, Duke Energy Ohio filed a motion with OPSB to establish a procedural schedule and filed supplemental information supporting its application. If approved, construction of the pipeline extension is expected to be completed before the 2020/2021 winter season. Duke Energy Ohio cannot predict the outcome of this matter.

Duke Energy Kentucky Rate Case

On September 1, 2017, Duke Energy Kentucky filed a rate case with the KPSC requesting an increase in electric base rates of approximately $49 million, which represents an approximate 15 percent increase on the average customer bill. Subsequent to the filing, Duke Energy Kentucky adjusted the requested amount to $30.1 million, in part to reflect the benefits of the Tax Act, representing an approximate 9 percent increase on the average customer bill. The rate increase is driven by increased investment in utility plant, increased operations and maintenance expenses, and recovery of regulatory assets. The application also includes implementation of the Environmental Surcharge Mechanism to recover environmental costs not recovered in base rates, requests to establish a Distribution Capital Investment Rider to recover incremental costs of specific programs, requests to establish a FERC Transmission Cost Reconciliation Rider to recover escalating transmission costs and modification to the Profit Sharing Mechanism to increase customers' share of proceeds from the benefits of owning generation and to mitigate shareholder risks associated with that generation. An evidentiary hearing ended on March 8, 2018, and the KPSC issued an order on April 13, 2018. Major components of the Order include approval of an $8.4 million increase in base rates with a return on equity at 9.725 percent based upon a capital structure of 49 percent equity on a total allocable capitalization of approximately $650 million. The Order excludes $50 million of rate base being recovered with carrying costs elsewhere (e.g., through rider mechanisms). The Order approves the Environmental Surcharge Mechanism Rider to begin recovery in June 2018 of capital-related environmental costs, including costs related to ash and ash disposal and environmental operation and maintenance expenses formerly recovered in base rates, including expenses for environmental reagents and emission allowances. The incremental revenue from this rider will be approximately $13 million on an annualized basis. The order implements the impact of the Tax Act by lowering the income tax component of the revenue requirement, flowing back protected excess deferred income taxes (EDIT) under allowable normalization rules and unprotected EDIT over 10 years. The Order settles all matters related to the Tax Act. The Order denies requests to implement riders for certain transmission costs and distribution capital investments. Duke Energy Kentucky implemented new base rates on May 1, 2018.

49

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Duke Energy Indiana

FERC Transmission Return on Equity Complaint

Customer groups have filed with the FERC complaints against MISO and its transmission-owning members, including Duke Energy Indiana, alleging, among other things, that the current base rate of return on equity earned by MISO transmission owners of 12.38 percent is unjust and unreasonable. The complaints claim, among other things, that the current base rate of return on equity earned by MISO transmission owners should be reduced to 8.67 percent. On January 5, 2015, the FERC issued an order accepting the MISO transmission owners' adder of 0.50 percent to the base rate of return on equity based on participation in an RTO subject to it being applied to a return on equity that is shown to be just and reasonable in the pending return on equity complaints. On December 22, 2015, the presiding FERC ALJ in the first complaint issued an Initial Decision in which the base rate of return on equity was set at 10.32 percent. On September 28, 2016, the Initial Decision in the first complaint was affirmed by FERC, but is subject to rehearing requests. On June 30, 2016, the presiding FERC ALJ in the second complaint issued an Initial Decision setting the base rate of return on equity at 9.70 percent. The Initial Decision in the second complaint is pending FERC review. On April 14, 2017, the U.S. Court of Appeals for the District of Columbia Circuit, in Emera Maine v. FERC, reversed and remanded certain aspects of the methodology employed by FERC to establish rates of return on equity. This decision may affect the outcome of the complaints against Duke Energy Indiana. Duke Energy Indiana currently believes these matters will not have a material impact on its results of operations, cash flows and financial position.

Benton County Wind Farm Dispute

On December 16, 2013, Benton County Wind Farm LLC (BCWF) filed a lawsuit against Duke Energy Indiana seeking damages for past generation losses alleging Duke Energy Indiana violated its obligations under a 2006 PPA by refusing to offer electricity to the market at negative prices. Damage claims continue to increase during times that BCWF is not dispatched. Under 2013 revised MISO market rules, Duke Energy Indiana is required to make a price offer to MISO for the power it proposes to sell into MISO markets and MISO determines whether BCWF is dispatched. Because market prices would have been negative due to increased market participation, Duke Energy Indiana determined it would not bid at negative prices in order to balance customer needs against BCWF's need to run. BCWF contends Duke Energy Indiana must bid at the lowest negative price to ensure dispatch, while Duke Energy Indiana contends it is not obligated to bid at any particular price, that it cannot ensure dispatch with any bid and that it has reasonably balanced the parties' interests. On July 6, 2015, the U.S. District Court for the Southern District of Indiana entered judgment against BCWF on all claims. BCWF appealed the decision and on December 9, 2016, the appeals court ruled in favor of BCWF. Duke Energy Indiana recorded an obligation and a regulatory asset related to the settlement amount in fourth quarter 2016. On June 30, 2017, the parties finalized a settlement agreement. Terms of the settlement included Duke Energy Indiana paying $29 million for back damages. Additionally, the parties agreed on the method by which the contract will be bid into the market in the future. The settlement amount was paid in June 2017. The IURC issued an order on September 27, 2017, approving recovery of the settlement amount through Duke Energy Indiana's fuel clause. The IURC order has been appealed to the Indiana Court of Appeals. Duke Energy Indiana cannot predict the outcome of this matter.

Piedmont

Tennessee Integrity Management Rider Filing

In November 2017, Piedmont filed a petition with the TPUC under the IMR mechanism to collect an additional $3.3 million in annual revenues, effective January 2018, based on the eligible capital investments for integrity and safety projects through October 31, 2017. In January 2018, Piedmont filed an amended computation under the IMR mechanism, revising the proposed increase in annual revenues to approximately $0.4 million based on the decrease in the corporate federal income tax rate effective January 1, 2018. A hearing on this matter was held on April 9, 2018, and a decision is expected mid-2018. Piedmont cannot predict the outcome of this matter.

OTHER REGULATORY MATTERS

Atlantic Coast Pipeline, LLC

On September 2, 2014, Duke Energy, Dominion Resources (Dominion), Piedmont and Southern Company Gas announced the formation of Atlantic Coast Pipeline, LLC (ACP) to build and own the proposed Atlantic Coast Pipeline (ACP pipeline), an approximately 600-mile interstate natural gas pipeline running from West Virginia to North Carolina. The ACP pipeline is designed to meet, in part, the needs identified by Duke Energy Carolinas, Duke Energy Progress and Piedmont. Dominion will build and operate the ACP pipeline and holds a leading ownership percentage in ACP of 48 percent. Duke Energy owns a 47 percent interest through its Gas Utilities and Infrastructure segment. Southern Company Gas maintains a 5 percent interest. See Note 11 for additional information related to Duke Energy's ownership interest.

Duke Energy Carolinas, Duke Energy Progress and Piedmont, among others, will be customers of the pipeline. Purchases will be made under several 20-year supply contracts, subject to state regulatory approval. On September 18, 2015, ACP filed an application with the FERC requesting a CPCN authorizing ACP to construct the pipeline. ACP executed a construction agreement in September 2016. ACP also requested approval of an open access tariff and the precedent agreements it entered into with future pipeline customers. In December 2016, FERC issued a draft Environmental Impact Statement (EIS) indicating that the proposed pipeline would not cause significant harm to the environment or protected populations. The FERC issued the final EIS in July 2017. On October 13, 2017, FERC issued an order approving the CPCN, subject to conditions. On October 16, 2017, ACP accepted the FERC order subject to reserving its right to file a request for rehearing or clarification on a timely basis. On November 9, 2017, ACP filed a request for rehearing on several limited issues. On December 12, 2017, ACP filed an answer to intervenors’ request for rehearing of the certificate order and for stay of the certificate order.

50

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

In December 2017, West Virginia issued a waiver of the state water quality permit in reliance on the U.S. Army Corps of Engineers national water quality permit and Virginia issued a conditional water quality permit subject to completion of additional studies and stormwater plans. In 2018, the FERC issued a series of Partial Notices to Proceed, which authorized the project to begin limited construction-related activities along the pipeline route, including supply header and compressors. North Carolina issued the state water quality permit in January 2018. The project remains subject to other pending federal and state approvals, which will allow full construction activities to begin. The ACP pipeline project has a targeted in-service date of late 2019.

Due to delays in obtaining the required permits to commence construction and the conditions imposed upon the project by the permits, ACP's project manager estimates the project's pipeline development costs have increased from a range of $5.0 billion to $5.5 billion to a range of $6.0 billion and $6.5 billion, excluding financing costs. Project construction activities, schedule and final costs are still subject to uncertainty due to potential additional permitting delays, construction productivity and other conditions and risks which could result in potential higher project costs and a potential delay in the targeted in-service date.

Sabal Trail Transmission, LLC

On May 4, 2015, Duke Energy acquired a 7.5 percent ownership interest in Sabal Trail from Spectra Energy Partners, LP, a master limited partnership, formed by Enbridge Inc. (formerly Spectra Energy Corp.). Spectra Energy Partners, LP holds a 50 percent ownership interest in Sabal Trail and NextEra Energy has a 42.5 percent ownership interest. Sabal Trail is a joint venture to construct a 515-mile natural gas pipeline (Sabal Trail pipeline) to transport natural gas to Florida. Total estimated project costs are approximately $3.2 billion. The Sabal Trail pipeline traverses Alabama, Georgia and Florida. The primary customers of the Sabal Trail pipeline, Duke Energy Florida and Florida Power & Light Company (FP&L), have each contracted to buy pipeline capacity for 25-year initial terms. See Note 11 for additional information related to Duke Energy's ownership interest.

On February 3, 2016, the FERC issued an order granting the request for a CPCN to construct and operate the pipeline. The Sabal Trail pipeline received other required regulatory approvals and the Phase 1 mainline was placed in service in July 2017. On October 12, 2017, Sabal Trail filed a request with FERC to place in service a lateral line to Duke Energy Florida's Citrus County Combined Cycle facility. This request is required to support commissioning and testing activities at the facility. On March 16, 2018, FERC approved the Citrus lateral and it was placed in service.

On September 21, 2016, intervenors filed an appeal of FERC's CPCN orders to the U.S. Court of Appeals for the District of Columbia Circuit (D.C. Circuit Court of Appeals). On August 22, 2017, the appeals court ruled against FERC in the case for failing to include enough information on the impact of greenhouse-gas emissions carried by the pipeline, vacated the CPCN order and remanded the case to FERC. In response to the August 2017 court decision, the FERC issued a draft Supplemental Environmental Impact Statement (SEIS) on September 27, 2017. On October 6, 2017, FERC and a group of industry intervenors, including Sabal Trail and Duke Energy Florida, filed separate petitions with the D.C. Circuit Court of Appeals requesting rehearing regarding the court's decision to vacate the CPCN order. On January 31, 2018, the D.C. Circuit Court of Appeals denied the requests for rehearing. On February 2, 2018, Sabal Trail filed a request with FERC for expedited issuance of its order on remand and reissuance of the CPCN. In the alternative, the pipeline requested that FERC issue a temporary emergency CPCN to allow for continued operations. On February 5, 2018, FERC issued the final SEIS but did not issue the order on remand. On February 6, 2018, FERC and the intervenors in this case each filed motions for stay with the D.C. Circuit Court to stay the court's mandate. The February 6, 2018, motions automatically stay the issuance of the court’s mandate until the later of seven days after the court denies the motions or the expiration of any stay granted by the court. On March 7, 2018, the D.C. Circuit Court of Appeals granted Sabal Trail’s stay request. On March 14, 2018, FERC issued its final order on remand.

Constitution Pipeline Company, LLC

Duke Energy owns a 24 percent ownership interest in Constitution, which is accounted for as an equity method investment. Constitution is a natural gas pipeline project slated to transport natural gas supplies from the Marcellus supply region in northern Pennsylvania to major northeastern markets. The pipeline will be constructed and operated by Williams Partners L.P., which has a 41 percent ownership share. The remaining interest is held by Cabot Oil and Gas Corporation and WGL Holdings, Inc. Before the permitting delays discussed below, Duke Energy's total anticipated contributions were approximately $229 million. As a result of the permitting delays and project uncertainty, total anticipated contributions by Duke Energy can no longer be reasonably estimated. Since April 2016, with the actions of the New York State Department of Environmental Conservation (NYSDEC), Constitution stopped construction and discontinued capitalization of future development costs until the project's uncertainty is resolved.

In December 2014, Constitution received approval from the FERC to construct and operate the proposed pipeline. However, on April 22, 2016, the NYSDEC denied Constitution’s application for a necessary water quality certification for the New York portion of the Constitution pipeline. Constitution filed legal actions in the U.S. Court of Appeals for the Second Circuit (U.S. Court of Appeals) challenging the legality and appropriateness of the NYSDEC’s decision and on August 18, 2017, the petition was denied in part and dismissed in part. In September 2017, Constitution filed a petition for a rehearing of portions of the decision unrelated to the water quality certification, which was denied by the U.S. Court of Appeals. In January 2018, Constitution petitioned the Supreme Court of the United States to review the U.S. Court of Appeals decision, and on April 30, 2018, the Supreme Court denied Constitution's petition. In October 2017, Constitution filed a petition for declaratory order requesting FERC to find that the NYSDEC waived its rights to issue a Section 401 water quality certification by not acting on Constitution's application within a reasonable period of time as required by statute. This petition was based on precedent established by another pipeline’s successful petition with FERC following a District of Columbia Circuit Court ruling. On January 11, 2018, FERC denied Constitution's petition. In February 2018, Constitution filed a rehearing request with FERC of its finding that the NYSDEC did not waive the Section 401 certification requirement. Constitution is currently unable to approximate an in-service date for the project due to the NYSDEC's denial of the water quality certification. The Constitution partners remain committed to the project and are evaluating next steps to move the project forward. Duke Energy cannot predict the outcome of this matter.

51

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

During the three months endedMarch 31, 2018, Duke Energy recorded an other-than-temporary impairment (OTTI) of $55 million within Equity in (losses) earnings of unconsolidated affiliates on Duke Energy's Condensed Consolidated Statements of Income. The charge represents the excess carrying value over the estimated fair value of the project, which was based on a Level 3 Fair Value measurement that was determined from the income approach using discounted cash flows. The impairment was primarily due to the recent actions taken by the courts and regulators to uphold the NYSDEC's denial of the certification and uncertainty associated with the remaining legal and regulatory challenges.

See Note 11 for additional information related to ownership interest and carrying value of the investment.

Potential Coal Plant Retirements

The Subsidiary Registrants periodically file Integrated Resource Plans (IRP) with their state regulatory commissions. The IRPs provide a view of forecasted energy needs over a long term (10 to 20 years) and options being considered to meet those needs. Recent IRPs filed by the Subsidiary Registrants included planning assumptions to potentially retire certain coal-fired generating facilities in Florida and Indiana earlier than their current estimated useful lives primarily because facilities do not have the requisite emission control equipment to meet EPA regulations recently approved or proposed.

The table below contains the net carrying value of generating facilities planned for retirement or included in recent IRPs as evaluated for potential retirement due to a lack of requisite environmental control equipment. Dollar amounts in the table below are included in Net property, plant and equipment on the Condensed Consolidated Balance Sheets as of March 31, 2018, and exclude capitalized asset retirement costs.

		Remaining Net
	Capacity	Book Value
	(in MW)	(in millions)
Duke Energy Carolinas
Allen Steam Station Units 1-3(a)	585	$	161
Progress Energy and Duke Energy Florida
Crystal River Units 1 and 2(b)	873	104
Duke Energy Indiana
Gallagher Units 2 and 4(c)	280	126
Total Duke Energy	1,738	$	391

(a) Duke Energy Carolinas will retire Allen Steam Station Units 1 through 3 by December 31, 2024, as part of the resolution of a lawsuit involving alleged New Source Review violations.

(b) Duke Energy Florida expects to retire these coal units by the end of 2018 to comply with environmental regulations.

(c) Duke Energy Indiana committed to either retire or stop burning coal at Gallagher Units 2 and 4 by December 31, 2022, as part of the settlement of Edwardsport IGCC matters.

Refer to the "Western Carolinas Modernization Plan" discussion above for details of Duke Energy Progress' planned retirements.

4. COMMITMENTS AND CONTINGENCIES

ENVIRONMENTAL

The Duke Energy Registrants are subject to federal, state and local regulations regarding air and water quality, hazardous and solid waste disposal and other environmental matters. These regulations can be changed from time to time, imposing new obligations on the Duke Energy Registrants. The following environmental matters impact all of the Duke Energy Registrants.

Remediation Activities

In addition to asset retirement obligations (ARO) recorded as a result of various environmental regulations, the Duke Energy Registrants are responsible for environmental remediation at various sites. These include certain properties that are part of ongoing operations and sites formerly owned or used by Duke Energy entities. These sites are in various stages of investigation, remediation and monitoring. Managed in conjunction with relevant federal, state and local agencies, remediation activities vary based upon site conditions and location, remediation requirements, complexity and sharing of responsibility. If remediation activities involve joint and several liability provisions, strict liability, or cost recovery or contribution actions, the Duke Energy Registrants could potentially be held responsible for environmental impacts caused by other potentially responsible parties and may also benefit from insurance policies or contractual indemnities that cover some or all cleanup costs. Liabilities are recorded when losses become probable and are reasonably estimable. The total costs that may be incurred cannot be estimated because the extent of environmental impact, allocation among potentially responsible parties, remediation alternatives and/or regulatory decisions have not yet been determined at all sites. Additional costs associated with remediation activities are likely to be incurred in the future and could be significant. Costs are typically expensed as Operation, maintenance and other on the Condensed Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable.

52

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The following tables contain information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Accounts Payable within Current Liabilities and Other within Other Noncurrent Liabilities on the Condensed Consolidated Balance Sheets.

	Three Months Ended March 31, 2018
				Duke					Duke			Duke			Duke			Duke
	Duke			Energy		Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas		Energy			Progress			Florida			Ohio			Indiana		Piedmont
Balance at beginning of period	$	81		$	10	$	15		$	3		$	12		$	47		$	5	$	2
Provisions/adjustments	4			1		3			1			1			—			1		—
Cash reductions	(5		)	—		(2		)	(1		)	(1		)	(3		)	—		—
Balance at end of period	$	80		$	11	$	16		$	3		$	12		$	44		$	6	$	2

	Three Months Ended March 31, 2017
				Duke					Duke		Duke			Duke			Duke
	Duke			Energy		Progress			Energy		Energy			Energy			Energy
(in millions)	Energy			Carolinas		Energy			Progress		Florida			Ohio			Indiana			Piedmont
Balance at beginning of period	$	98		$	10	$	18		$	3	$	14		$	59		$	10		$	1
Provisions/adjustments	6			1		—			—		1			4			(1		)	1
Cash reductions	(6		)	—		(1		)	—		(1		)	(4		)	—			—
Balance at end of period	$	98		$	11	$	17		$	3	$	14		$	59		$	9		$	2

Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are not material except as presented in the table below.

(in millions)
Duke Energy	$	57
Duke Energy Carolinas	19
Duke Energy Ohio	30
Piedmont	2

LITIGATION

Duke Energy Carolinas and Duke Energy Progress

Coal Ash Insurance Coverage Litigation

In March 2017, Duke Energy Carolinas and Duke Energy Progress filed a civil action in North Carolina Superior Court against various insurance providers. The lawsuit seeks payment for coal ash-related liabilities covered by third-party liability insurance policies. The insurance policies were issued between 1971 and 1986 and provide third-party liability insurance for property damage. The civil action seeks damages for breach of contract and indemnification for costs arising from the Coal Ash Act and the EPA CCR rule at 15 coal-fired plants in North Carolina and South Carolina. The parties are engaged in discovery. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter.

NCDEQ State Enforcement Actions

In the first quarter of 2013, the Southern Environmental Law Center (SELC) sent notices of intent to sue Duke Energy Carolinas and Duke Energy Progress related to alleged Clean Water Act (CWA) violations from coal ash basins at two of their coal-fired power plants in North Carolina. The NCDEQ filed enforcement actions against Duke Energy Carolinas and Duke Energy Progress alleging violations of water discharge permits and North Carolina groundwater standards. The cases have been consolidated and are being heard before a single judge in the North Carolina Superior Court.

On August 16, 2013, the NCDEQ filed an enforcement action against Duke Energy Carolinas and Duke Energy Progress related to their remaining plants in North Carolina, alleging violations of the CWA and violations of the North Carolina groundwater standards. Both of these cases have been assigned to the judge handling the enforcement actions discussed above. SELC is representing several environmental groups who have been permitted to intervene in these cases.

53

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The court issued orders in 2016 granting Motions for Partial Summary Judgment for seven of the 14 North Carolina plants named in the enforcement actions. On February 13, 2017, the court issued an order denying motions for partial summary judgment brought by both the environmental groups and Duke Energy Carolinas and Duke Energy Progress for the remaining seven plants. On March 15, 2017, Duke Energy Carolinas and Duke Energy Progress filed a Notice of Appeal to challenge the trial court’s order. The parties were unable to reach an agreement at mediation in April 2017. The parties submitted briefs to the court on remaining issues to be tried and a ruling is pending. On August 22, 2017, Duke Energy Carolinas and Duke Energy Progress filed a Petition for Discretionary Review, requesting the North Carolina Supreme Court to accept the appeal. On August 24, 2017, SELC filed a motion to dismiss the appeal. Duke Energy Carolinas' and Duke Energy Progress’ opening appellate briefs were filed on October 12, 2017, and briefing is now complete. Argument was held on February 8, 2018.

It is not possible to predict any liability or estimate any damages Duke Energy Carolinas or Duke Energy Progress might incur in connection with these matters.

Federal Citizens Suits

On June 13, 2016, the Roanoke River Basin Association (RRBA) filed a federal citizen suit in the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Mayo Plant. On August 19, 2016, Duke Energy Progress filed a Motion to Dismiss. On April 26, 2017, the court entered an order dismissing four of the claims in the federal citizen suit. Two claims relating to alleged violations of National Pollutant Discharge Elimination System (NPDES) permit provisions survived the motion to dismiss, and Duke Energy Progress filed its response on May 10, 2017. Duke Energy Progress and RRBA each filed motions for summary judgment on March 23, 2018.

On May 16, 2017, RRBA filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina, which asserts two claims relating to alleged violations of NPDES permit provisions at the Roxboro plant and one claim relating to the use of nearby water bodies. Duke Energy Progress and RRBA each filed motions for summary judgment on April 17, 2018.

On May 8, 2018, on motion from Duke Energy Progress, the Court ordered trial in both of the above matters to be consolidated and has set a trial date for December 3, 2018.

On June 20, 2017, RRBA filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina challenging the closure plans at the Mayo Plant under the EPA CCR Rule. Duke Energy Progress filed a motion to dismiss, which was granted by the court on March 30, 2018. RRBA had until April 30, 2018 to file an appeal to the Fourth Circuit but did not do so.

On August 2, 2017, RRBA filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina challenging the closure plans at the Roxboro Plant under the EPA CCR Rule. Duke Energy Progress filed a motion to dismiss on October 2, 2017.

On December 6, 2017, various parties filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina for alleged violations at Duke Energy Carolinas' Belews Creek Steam Station (Belews Creek) under the CWA. Duke Energy Carolinas filed a motion to dismiss on February 5, 2018.

It is not possible to predict whether Duke Energy Carolinas or Duke Energy Progress will incur any liability or to estimate the damages, if any, they might incur in connection with these matters.

Groundwater Contamination Claims

Beginning in May 2015, a number of residents living in the vicinity of the North Carolina facilities with ash basins received letters from the NCDEQ advising them not to drink water from the private wells on their land tested by the NCDEQ as the samples were found to have certain substances at levels higher than the criteria set by the North Carolina Department of Health and Human Services (DHHS). Results of Comprehensive Site Assessments testing performed by Duke Energy under the Coal Ash Act have been consistent with historical data provided to state regulators over many years. The DHHS and NCDEQ sent follow-up letters on October 15, 2015, to residents near coal ash basins who had their wells tested, stating that private well samplings at a considerable distance from coal ash basins, as well as some municipal water supplies, contain similar levels of vanadium and hexavalent chromium, which led investigators to believe these constituents are naturally occurring. In March 2016, DHHS rescinded the advisories.

Duke Energy Carolinas and Duke Energy Progress have received formal demand letters from residents near Duke Energy Carolinas' and Duke Energy Progress' coal ash basins. The residents claim damages for nuisance and diminution in property value, among other things. The parties held three days of mediation discussions that ended at an impasse. On January 6, 2017, Duke Energy Carolinas and Duke Energy Progress received the plaintiffs' notice of their intent to file suits should the matter not settle. The NCDEQ preliminarily approved Duke Energy’s permanent water solution plans on January 13, 2017, and as a result shortly thereafter, Duke Energy issued a press release, providing additional details regarding the homeowner compensation package. This package consists of three components: (i) a $5,000 goodwill payment to each eligible well owner to support the transition to a new water supply, (ii) where a public water supply is available and selected by the eligible well owner, a stipend to cover 25 years of water bills and (iii) the Property Value Protection Plan. The Property Value Protection Plan is a program offered by Duke Energy designed to guarantee eligible plant neighbors the fair market value of their residential property should they decide to sell their property during the time that the plan is offered. Duke Energy Carolinas and Duke Energy Progress have recognized reserves of $16 million and $3 million, respectively.

54

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

On August 23, 2017, a class-action suit was filed in Wake County Superior Court, North Carolina, against Duke Energy Carolinas and Duke Energy Progress on behalf of certain property owners living near coal ash impoundments at Allen, Asheville, Belews Creek, Buck, Cliffside, Lee, Marshall, Mayo and Roxboro. The class is defined as those who are “well-eligible” under the Coal Ash Act or those to whom Duke Energy has promised a permanent replacement water supply and seeks declaratory and injunctive relief, along with compensatory damages. Plaintiffs allege that Duke Energy’s improper maintenance of coal ash impoundments caused harm, particularly through groundwater contamination. Despite NCDEQ’s preliminary approval, Plaintiffs contend that Duke Energy’s proposed permanent water solutions plan fails to comply with the Coal Ash Act. On September 28, 2017, Duke Energy Carolinas and Duke Energy Progress filed a Motion to Dismiss and Motion to Strike the class designation. The parties entered into a Settlement Agreement on January 24, 2018, which resulted in the dismissal of the underlying class action on January 25, 2018.

On September 14, 2017, a complaint was filed against Duke Energy Progress in New Hanover County Superior Court by a group of homeowners residing approximately one mile from Duke Energy Progress' Sutton Steam Plant (Sutton). The homeowners allege that coal ash constituents have been migrating from ash impoundments at Sutton into their groundwater for decades and that in 2015, Duke Energy Progress discovered these releases of coal ash, but failed to notify any officials or neighbors and failed to take remedial action. The homeowners claim unspecified physical and mental injuries as a result of consuming their well water and seek actual damages for personal injury, medical monitoring and punitive damages. On March 6, 2018, Plaintiffs' counsel voluntarily dismissed the action without prejudice.

It is not possible to estimate the maximum exposure of loss, if any, that may occur in connection with future claims that might be made by these residents.

Asbestos-related Injuries and Damages Claims

Duke Energy Carolinas has experienced numerous claims for indemnification and medical cost reimbursement related to asbestos exposure. These claims relate to damages for bodily injuries alleged to have arisen from exposure to or use of asbestos in connection with construction and maintenance activities conducted on its electric generation plants prior to 1985. As of March 31, 2018, there were 143 asserted claims for non-malignant cases with cumulative relief sought of up to $37 million, and 58 asserted claims for malignant cases with cumulative relief sought of up to $19 million. Based on Duke Energy Carolinas’ experience, it is expected that the ultimate resolution of most of these claims likely will be less than the amount claimed.

Duke Energy Carolinas has recognized asbestos-related reserves of $487 million at March 31, 2018, and $489 million at December 31, 2017. These reserves are classified in Other within Other Noncurrent Liabilities and Other within Current Liabilities on the Condensed Consolidated Balance Sheets. These reserves are based upon the minimum amount of the range of loss for current and future asbestos claims through 2037, are recorded on an undiscounted basis and incorporate anticipated inflation. In light of the uncertainties inherent in a longer-term forecast, management does not believe they can reasonably estimate the indemnity and medical costs that might be incurred after 2037 related to such potential claims. It is possible Duke Energy Carolinas may incur asbestos liabilities in excess of the recorded reserves.

Duke Energy Carolinas has third-party insurance to cover certain losses related to asbestos-related injuries and damages above an aggregate self-insured retention. Duke Energy Carolinas’ cumulative payments began to exceed the self-insurance retention in 2008. Future payments up to the policy limit will be reimbursed by the third-party insurance carrier. The insurance policy limit for potential future insurance recoveries indemnification and medical cost claim payments is $797 million in excess of the self-insured retention. Receivables for insurance recoveries were $585 million at March 31, 2018, and December 31, 2017. These amounts are classified in Other within Other Noncurrent Assets and Receivables within Current Assets on the Condensed Consolidated Balance Sheets. Duke Energy Carolinas is not aware of any uncertainties regarding the legal sufficiency of insurance claims. Duke Energy Carolinas believes the insurance recovery asset is probable of recovery as the insurance carrier continues to have a strong financial strength rating.

Duke Energy Progress and Duke Energy Florida

Spent Nuclear Fuel Matters

On October 16, 2014, Duke Energy Progress and Duke Energy Florida sued the U.S. in the U.S. Court of Federal Claims. The lawsuit claimed the Department of Energy breached a contract in failing to accept spent nuclear fuel under the Nuclear Waste Policy Act of 1982 and asserted damages for the cost of on-site storage. Duke Energy Progress and Duke Energy Florida asserted damages for the period January 1, 2011, through December 31, 2013, of $48 million and $25 million, respectively. On November 17, 2017, the Court awarded Duke Energy Progress and Duke Energy Florida $48 million and $21 million, respectively, subject to appeal. No appeals were filed and Duke Energy Progress and Duke Energy Florida recognized the recoveries in the first quarter of 2018. Claims for all periods through 2013 have been resolved. Additional claims will be filed in 2018.

Duke Energy Progress

Gypsum Supply Agreement Matter

On June 30, 2017, CertainTeed Gypsum NC, Inc. (CertainTeed) filed a declaratory judgment action against Duke Energy Progress in the North Carolina Business Court relating to a gypsum supply agreement. In its complaint, CertainTeed sought an order from the court declaring that the minimum amount of gypsum Duke Energy Progress must provide to CertainTeed under the supply agreement is 50,000 tons per month through 2029. On January 29, 2018, CertainTeed filed a request to amend its Complaint and seek a preliminary injunction requiring Duke Energy Progress to provide 50,000 tons of gypsum per month through the trial date. In advance of the hearing on the Motion for Preliminary Injunction, the parties reached an agreement under which Duke Energy Progress would deliver 50,000 tons of gypsum per month through June 2018. If the Court determines that Duke Energy Progress was not obligated to provide that amount per month, CertainTeed will reimburse Duke Energy Progress. Discovery is currently underway and trial is set for July 2018. If Duke Energy Progress does not prevail at trial, Duke Energy Progress will either have to purchase additional gypsum on the open market to fulfill its contractual obligation through 2029 or pay some amount of liquidated damages. Duke Energy Progress cannot predict the outcome of this matter.

55

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Duke Energy Florida

Class Action Lawsuit

On February 22, 2016, a lawsuit was filed in the U.S. District Court for the Southern District of Florida on behalf of a putative class of Duke Energy Florida and FP&L’s customers in Florida. The suit alleges the State of Florida’s nuclear power plant cost recovery statutes (NCRS) are unconstitutional and pre-empted by federal law. Plaintiffs claim they are entitled to repayment of all money paid by customers of Duke Energy Florida and FP&L as a result of the NCRS, as well as an injunction against any future charges under those statutes. The constitutionality of the NCRS has been challenged unsuccessfully in a number of prior cases on alternative grounds. Duke Energy Florida and FP&L filed motions to dismiss the complaint on May 5, 2016. On September 21, 2016, the Court granted the motions to dismiss with prejudice. Plaintiffs filed a motion for reconsideration, which was denied. On January 4, 2017, plaintiffs filed a notice of appeal to the Eleventh Circuit U.S. Court of Appeals. The appeal, which has been fully briefed, was heard on August 22, 2017, and a decision is pending. Duke Energy Florida cannot predict the outcome of this appeal.

Westinghouse Contract Litigation

On March 28, 2014, Duke Energy Florida filed a lawsuit against Westinghouse in the U.S. District Court for the Western District of North Carolina. The lawsuit seeks recovery of $54 million in milestone payments in excess of work performed under an EPC for Levy as well as a determination by the court of the amounts due to Westinghouse as a result of the termination of an EPC contract. Duke Energy Florida recognized an exit obligation as a result of the termination of the EPC. On March 31, 2014, Westinghouse filed a separate lawsuit against Duke Energy Florida in U.S. District Court for the Western District of Pennsylvania alleging damages under the same EPC contract in excess of $510 million for engineering and design work, costs to end supplier contracts and an alleged termination fee. On June 9, 2014, the judge in the North Carolina case ruled that the litigation would proceed in the Western District of North Carolina.

On July 11, 2016, Duke Energy Florida and Westinghouse filed separate Motions for Summary Judgment. On September 29, 2016, the court issued its ruling, granting Westinghouse a $30 million termination fee claim and dismissing Duke Energy Florida's $54 million refund claim. Westinghouse's claim for termination costs continued to trial. Following a trial on the matter, the court issued an order in December 2016 denying Westinghouse’s claim for termination costs and reaffirming its earlier ruling in favor of Westinghouse on the $30 million termination fee. Judgment was entered against Duke Energy Florida in the amount of approximately $34 million, which includes prejudgment interest. Westinghouse has appealed the trial court's order to the U.S. Court of Appeals for the Fourth Circuit (Fourth Circuit Court) and Duke Energy Florida has cross-appealed.

On March 29, 2017, Westinghouse filed Chapter 11 bankruptcy in the Southern District of New York, which automatically stayed the appeal. On May 23, 2017, the bankruptcy court entered an order lifting the stay with respect to the appeal. Briefing of the appeal concluded on October 20, 2017. Westinghouse and Duke Energy Florida executed a settlement agreement resolving this matter on April 5, 2018, which has been filed with the bankruptcy court for approval. The settlement provides that the appeal will be dismissed and Duke Energy Florida will pay the judgment amount of approximately $34 million. This reserve is classified in Other within Other Noncurrent Liabilities on the Condensed Consolidated Balance Sheet. In light of the settlement, the Fourth Circuit Court agreed to stay the appeal pending bankruptcy court approval of the settlement. Duke Energy cannot predict the ultimate outcome of this appeal or the bankruptcy court's approval of the pending settlement.

MGP Cost Recovery Action

On December 30, 2011, Duke Energy Florida filed a lawsuit against FirstEnergy Corp. (FirstEnergy) to recover investigation and remediation costs incurred by Duke Energy Florida in connection with the restoration of two former MGP sites in Florida. Duke Energy Florida alleged that FirstEnergy, as the successor to Associated Gas & Electric Co., owes past and future contribution and response costs of up to $43 million for the investigation and remediation of MGP sites. On December 6, 2016, the trial court entered judgment against Duke Energy Florida in the case. In January 2017, Duke Energy Florida appealed the decision to the U.S. Court of Appeals for the 6th Circuit, which affirmed the trial court's ruling on April 10, 2018. Duke Energy Florida cannot predict the outcome of this appeal.

Other Litigation and Legal Proceedings

The Duke Energy Registrants are involved in other legal, tax and regulatory proceedings arising in the ordinary course of business, some of which involve significant amounts. The Duke Energy Registrants believe the final disposition of these proceedings will not have a material effect on their results of operations, cash flows or financial position.

The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters, excluding asbestos-related reserves and the exit obligation related to the termination of an EPC contract discussed above. Reserves are classified on the Condensed Consolidated Balance Sheets in Other within Other Noncurrent Liabilities and Accounts payable and Other within Current Liabilities. The reasonably possible range of loss in excess of recorded reserves is not material, other than as described above.

(in millions)	March 31, 2018		December 31, 2017
Reserves for Legal Matters
Duke Energy	$	74	$	88
Duke Energy Carolinas	20		30
Progress Energy	51		55
Duke Energy Progress	10		13
Duke Energy Florida	24		24
Piedmont	2		2

56

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

OTHER COMMITMENTS AND CONTINGENCIES

General

As part of their normal business, the Duke Energy Registrants are party to various financial guarantees, performance guarantees and other contractual commitments to extend guarantees of credit and other assistance to various subsidiaries, investees and other third parties. These guarantees involve elements of performance and credit risk, which are not fully recognized on the Condensed Consolidated Balance Sheets and have unlimited maximum potential payments. However, the Duke Energy Registrants do not believe these guarantees will have a material effect on their results of operations, cash flows or financial position.

In addition, the Duke Energy Registrants enter into various fixed-price, noncancelable commitments to purchase or sell power or natural gas, take-or-pay arrangements, transportation, or throughput agreements and other contracts that may or may not be recognized on their respective Condensed Consolidated Balance Sheets. Some of these arrangements may be recognized at fair value on their respective Condensed Consolidated Balance Sheets if such contracts meet the definition of a derivative and the normal purchase/normal sale (NPNS) exception does not apply. In most cases, the Duke Energy Registrants’ purchase obligation contracts contain provisions for price adjustments, minimum purchase levels and other financial commitments.

5. DEBT AND CREDIT FACILITIES

SUMMARY OF SIGNIFICANT DEBT ISSUANCES

The following table summarizes significant debt issuances (in millions).

				Three Months Ended March 31, 2018
						Duke		Duke
	Maturity	Interest		Duke		Energy		Energy
Issuance Date	Date	Rate		Energy		(Parent)		Carolinas
Unsecured Debt
March 2018(a)	April 2025	3.950	%	$	250	$	250	$	—
First Mortgage Bonds
March 2018(b)	March 2023	3.050	%	500		—		500
March 2018(b)	March 2048	3.950	%	500		—		500
Total issuances				$	1,250	$	250	$	1,000

(a) Debt issued to pay down short-term debt.

(b) Debt issued to repay at maturity a $300 million first mortgage bond due April 2018, pay down intercompany short-term debt and for general corporate purposes.

CURRENT MATURITIES OF LONG-TERM DEBT

The following table shows the significant components of Current Maturities of Long-Term Debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings.

(in millions)	Maturity Date	Interest Rate			March 31, 2018
Unsecured Debt
Duke Energy (Parent)	June 2018	6.250	%		$	250
Duke Energy (Parent)	June 2018	2.100	%		500
Piedmont	December 2018	2.821	%	(b)	250
Progress Energy	March 2019	7.050	%		450
First Mortgage Bonds
Duke Energy Carolinas	April 2018	5.100	%		300
Duke Energy Florida	June 2018	5.650	%		500
Duke Energy Carolinas	November 2018	7.000	%		500
Duke Energy Progress	January 2019	5.300	%		600
Other(a)					601
Current maturities of long-term debt					$	3,951

(a)    Includes capital lease obligations, amortizing debt and small bullet maturities.

(b)    Debt issuance has a floating interest rate.

57

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

AVAILABLE CREDIT FACILITIES

Master Credit Facility

In January 2018, Duke Energy extended the termination date of substantially all of its existing $8 billion Master Credit Facility capacity from March 16, 2022 to March 16, 2023. In May 2018, Duke Energy completed the extension process with 100 percent of all commitments to the Master Credit Facility extending to March 16, 2023. The Duke Energy Registrants, excluding Progress Energy (Parent), have borrowing capacity under the Master Credit Facility up to a specified sublimit for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower. The amount available under the Master Credit Facility has been reduced to backstop issuances of commercial paper, certain letters of credit and variable-rate demand tax-exempt bonds that may be put to the Duke Energy Registrants at the option of the holder. Duke Energy Carolinas and Duke Energy Progress are also required to each maintain $250 million of available capacity under the Master Credit Facility as security to meet obligations under plea agreements reached with the U.S. Department of Justice in 2015 related to violations at North Carolina facilities with ash basins. The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility.

	March 31, 2018
				Duke			Duke			Duke			Duke			Duke			Duke
	Duke			Energy			Energy			Energy			Energy			Energy			Energy
(in millions)	Energy			(Parent)			Carolinas			Progress			Florida			Ohio			Indiana			Piedmont
Facility size(a)	$	8,000		$	2,650		$	1,550		$	1,250		$	800		$	450		$	600		$	700
Reduction to backstop issuances
Commercial paper(b)	(2,602		)	(1,281		)	(340		)	(464		)	—			(140		)	(282		)	(95		)
Outstanding letters of credit	(59		)	(50		)	(4		)	(2		)	(1		)	—			—			(2		)
Tax-exempt bonds	(81		)	—			—			—			—			—			(81		)	—
Coal ash set-aside	(500		)	—			(250		)	(250		)	—			—			—			—
Available capacity under the Master Credit Facility	$	4,758		$	1,319		$	956		$	534		$	799		$	310		$	237		$	603

(a) Represents the sublimit of each borrower.

(b) Duke Energy issued $625 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies on the Condensed Consolidated Balance Sheets.

Three-Year Revolving Credit Facility

Duke Energy (Parent) has a $1.0 billion revolving credit facility (the Three Year Revolver) through June 2020. As of March 31, 2018, $500 million has been drawn under the Three Year Revolver. This balance is classified as Long-Term Debt on Duke Energy's Condensed Consolidated Balance Sheets. Any undrawn commitments can be drawn, and borrowings can be prepaid, at any time throughout the term of the facility. The terms and conditions of the Three Year Revolver are generally consistent with those governing Duke Energy's Master Credit Facility.

6. GOODWILL

Duke Energy

The following table presents the goodwill by reportable operating segment included on Duke Energy's Condensed Consolidated Balance Sheets at March 31, 2018, and December 31, 2017.

	Electric Utilities		Gas Utilities		Commercial
(in millions)	and Infrastructure		and Infrastructure		Renewables			Total
Goodwill balance	$	17,379	$	1,924	$	122		$	19,425
Accumulated impairment charges	—		—		(29		)	(29		)
Goodwill, adjusted for accumulated impairment charges	$	17,379	$	1,924	$	93		$	19,396

Duke Energy Ohio

Duke Energy Ohio's Goodwill balance of $920 million, allocated $596 million to Electric Utilities and Infrastructure and $324 million to Gas Utilities and Infrastructure, is presented net of accumulated impairment charges of $216 million on the Condensed Consolidated Balance Sheets at March 31, 2018, and December 31, 2017.

Progress Energy

Progress Energy's Goodwill is included in the Electric Utilities and Infrastructure operating segment and there are no accumulated impairment charges.

Piedmont

Piedmont's Goodwill is included in the Gas Utilities and Infrastructure operating segment and there are no accumulated impairment charges.

58

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

7. RELATED PARTY TRANSACTIONS

The Subsidiary Registrants engage in related party transactions in accordance with applicable state and federal commission regulations. Refer to the Condensed Consolidated Balance Sheets of the Subsidiary Registrants for balances due to or due from related parties. Material amounts related to transactions with related parties included on the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table.

	Three Months Ended March 31,
(in millions)	2018		2017
Duke Energy Carolinas
Corporate governance and shared service expenses(a)	$	220	$	221
Indemnification coverages(b)	6		6
JDA revenue(c)	34		16
JDA expense(c)	54		31
Intercompany natural gas purchases(d)	4		1
Progress Energy
Corporate governance and shared service expenses(a)	$	191	$	170
Indemnification coverages(b)	8		10
JDA revenue(c)	54		31
JDA expense(c)	34		16
Intercompany natural gas purchases(d)	19		19
Duke Energy Progress
Corporate governance and shared service expenses(a)	$	118	$	100
Indemnification coverages(b)	3		4
JDA revenue(c)	54		31
JDA expense(c)	34		16
Intercompany natural gas purchases(d)	19		19
Duke Energy Florida
Corporate governance and shared service expenses(a)	$	73	$	70
Indemnification coverages(b)	5		6
Duke Energy Ohio
Corporate governance and shared service expenses(a)	$	89	$	92
Indemnification coverages(b)	1		1
Duke Energy Indiana
Corporate governance and shared service expenses(a)	$	101	$	95
Indemnification coverages(b)	2		2
Piedmont
Corporate governance and shared service expenses(a)	$	36	$	5
Indemnification coverages(b)	1		1
Intercompany natural gas sales(d)	23		20

(a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are primarily recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(c) Duke Energy Carolinas and Duke Energy Progress participate in a Joint Dispatch Agreement (JDA), which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power and expenses from the purchase of power pursuant to the JDA are recorded in Operating Revenues and Fuel used in electric generation and purchased power, respectively, on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(d) Piedmont provides long-term natural gas delivery service to certain Duke Energy Carolinas and Duke Energy Progress natural gas-fired generation facilities. Piedmont records the sales in Regulated natural gas revenues, and Duke Energy Carolinas and Duke Energy Progress record the related purchases in Fuel used in electric generation and purchased power on their respective Condensed Consolidated Statements of Operations and Comprehensive Income. The amounts are not eliminated in accordance with rate-based accounting regulations.

59

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

In addition to the amounts presented above, the Subsidiary Registrants have other affiliate transactions, including rental of office space, participation in a money pool arrangement, other operational transactions and their proportionate share of certain charged expenses. See Note 6 to the Consolidated Financial Statements in the Annual Report on Form 10-K/A for the year ended December 31, 2017, for more information regarding the money pool. These transactions of the Subsidiary Registrants were not material for the three months ended March 31, 2018, and 2017.

As discussed in Note 11, certain trade receivables have been sold by Duke Energy Ohio and Duke Energy Indiana to Cinergy Receivables Company LLC (CRC), an affiliate formed by a subsidiary of Duke Energy. The proceeds obtained from the sales of receivables are largely cash but also include a subordinated note from the affiliate for a portion of the purchase price.

Equity Method Investments

Piedmont has related party transactions as a customer of its equity method investments in natural gas storage and transportation facilities. The following table presents expenses for the three months ended March 31, 2018, and 2017, which are included in Cost of natural gas on Piedmont's Condensed Consolidated Statements of Operations and Comprehensive Income.

		Three Months Ended March 31,
(in millions)	Type of expense	2018		2017
Cardinal	Transportation Costs	$	2	$	2
Pine Needle	Natural Gas Storage Costs	2		2
Hardy Storage	Natural Gas Storage Costs	2		2
Total		$	6	$	6

Piedmont had accounts payable to its equity method investments of $2 million at March 31, 2018, and December 31, 2017, related to these transactions. These amounts are included in Accounts payable on the Condensed Consolidated Balance Sheets.

Intercompany Income Taxes

Duke Energy and the Subsidiary Registrants file a consolidated federal income tax return and other state and jurisdictional returns. The Subsidiary Registrants have a tax sharing agreement with Duke Energy for the allocation of consolidated tax liabilities and benefits. Income taxes recorded represent amounts the Subsidiary Registrants would incur as separate C-Corporations. The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants.

	Duke				Duke		Duke		Duke		Duke
	Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
March 31, 2018
Intercompany income tax receivable	$	—	$	183	$	13	$	9	$	—	$	—	$	—
Intercompany income tax payable	9		—		—		—		3		18		43
December 31, 2017
Intercompany income tax receivable	$	—	$	168	$	—	$	44	$	22	$	—	$	7
Intercompany income tax payable	44		—		21		—		—		35		—

8. DERIVATIVES AND HEDGING

The Duke Energy Registrants use commodity and interest rate contracts to manage commodity price risk and interest rate risk. The primary use of commodity derivatives is to hedge the generation portfolio against changes in the prices of electricity and natural gas. Piedmont enters into natural gas supply contracts to provide diversification, reliability and natural gas cost benefits to its customers. Interest rate swaps are used to manage interest rate risk associated with borrowings.

All derivative instruments not identified as NPNS are recorded at fair value as assets or liabilities on the Condensed Consolidated Balance Sheets. Cash collateral related to derivative instruments executed under master netting arrangements is offset against the collateralized derivatives on the Condensed Consolidated Balance Sheets. The cash impacts of settled derivatives are recorded as operating activities on the Condensed Consolidated Statements of Cash Flows.

INTEREST RATE RISK

The Duke Energy Registrants are exposed to changes in interest rates as a result of their issuance or anticipated issuance of variable-rate and fixed-rate debt and commercial paper. Interest rate risk is managed by limiting variable-rate exposures to a percentage of total debt and by monitoring changes in interest rates. To manage risk associated with changes in interest rates, the Duke Energy Registrants may enter into interest rate swaps, U.S. Treasury lock agreements and other financial contracts. In anticipation of certain fixed-rate debt issuances, a series of forward-starting interest rate swaps or Treasury locks may be executed to lock in components of current market interest rates. These instruments are later terminated prior to or upon the issuance of the corresponding debt.

60

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Cash Flow Hedges

For a derivative designated as hedging the exposure to variable cash flows of a future transaction, referred to as a cash flow hedge, the effective portion of the derivative's gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings once the future transaction impacts earnings. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt. Gains and losses reclassified out of AOCI for the three months ended March 31, 2018 and 2017 were not material. Duke Energy's interest rate derivatives designated as hedges include interest rate swaps used to hedge existing debt within the Commercial Renewables business.

Undesignated Contracts

Undesignated contracts include contracts not designated as a hedge because they are accounted for under regulatory accounting and contracts that do not qualify for hedge accounting.

Duke Energy’s interest rate swaps for its regulated operations employ regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the swaps are deferred as regulatory liabilities or regulatory assets, respectively. Regulatory assets and liabilities are amortized consistent with the treatment of the related costs in the ratemaking process. The accrual of interest on the swaps is recorded as Interest Expense.

The following table shows notional amounts of outstanding derivatives related to interest rate risk.

	March 31, 2018
			Duke				Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio
Cash flow hedges(a)	$	660	$	—	$	—	$	—	$	—	$	—
Undesignated contracts	527		—		500		250		250		27
Total notional amount	$	1,187	$	—	$	500	$	250	$	250	$	27

	December 31, 2017
			Duke				Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio
Cash flow hedges(a)	$	660	$	—	$	—	$	—	$	—	$	—
Undesignated contracts	927		400		500		250		250		27
Total notional amount	$	1,587	$	400	$	500	$	250	$	250	$	27

(a) Duke Energy includes amounts related to consolidated VIEs of $660 million as of March 31, 2018, and December 31, 2017.

COMMODITY PRICE RISK

The Duke Energy Registrants are exposed to the impact of changes in the prices of electricity purchased and sold in bulk power markets and coal and natural gas purchases, including Piedmont's natural gas supply contracts. Exposure to commodity price risk is influenced by a number of factors including the term of contracts, the liquidity of markets and delivery locations. For the Subsidiary Registrants, bulk power electricity and coal and natural gas purchases flow through fuel adjustment clauses, formula-based contracts or other cost-sharing mechanisms. Differences between the costs included in rates and the incurred costs, including undesignated derivative contracts, are largely deferred as regulatory assets or regulatory liabilities. Piedmont policies allow for the use of financial instruments to hedge commodity price risks. The strategy and objective of these hedging programs are to use the financial instruments to reduce natural gas costs volatility for customers.

61

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Volumes

The tables below include volumes of outstanding commodity derivatives. Amounts disclosed represent the absolute value of notional volumes of commodity contracts excluding NPNS. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown.

	March 31, 2018
		Duke		Duke	Duke	Duke
	Duke	Energy	Progress	Energy	Energy	Energy
	Energy	Carolinas	Energy	Progress	Florida	Indiana	Piedmont
Electricity (gigawatt-hours)	16	—	—	—	—	16	—
Natural gas (millions of dekatherms)	765	110	179	149	30	2	474

	December 31, 2017
		Duke		Duke	Duke	Duke
	Duke	Energy	Progress	Energy	Energy	Energy
	Energy	Carolinas	Energy	Progress	Florida	Indiana	Piedmont
Electricity (gigawatt-hours)	34	—	—	—	—	34	—
Natural gas (millions of dekatherms)	770	105	183	133	50	2	480

62

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

LOCATION AND FAIR VALUE OF DERIVATIVE ASSETS AND LIABILITIES RECOGNIZED ON THE CONDENSED CONSOLIDATED BALANCE SHEETS

The following tables show the fair value and balance sheet location of derivative instruments. Although derivatives subject to master netting arrangements are netted on the Condensed Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.

Derivative Assets	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	14	$	2	$	3	$	2	$	1	$	1	$	7	$	1
Noncurrent	1		—		—		—		—		—		—		—
Total Derivative Assets – Commodity Contracts	$	15	$	2	$	3	$	2	$	1	$	1	$	7	$	1
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	1	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	21		—		—		—		—		—		—		—
Total Derivative Assets – Interest Rate Contracts	$	22	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Total Derivative Assets	$	37	$	2	$	3	$	2	$	1	$	1	$	7	$	1

Derivative Liabilities	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	26	$	5	$	8	$	6	$	3	$	—	$	—	$	13
Noncurrent	140		6		15		6		—		—		—		119
Total Derivative Liabilities – Commodity Contracts	$	166	$	11	$	23	$	12	$	3	$	—	$	—	$	132
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	4	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	3		—		—		—		—		—		—		—
Not Designated as Hedging Instruments
Current	3		—		3		2		1		—		—		—
Noncurrent	14		—		11		7		3		4		—		—
Total Derivative Liabilities – Interest Rate Contracts	$	24	$	—	$	14	$	9	$	4	$	4	$	—	$	—
Total Derivative Liabilities	$	190	$	11	$	37	$	21	$	7	$	4	$	—	$	132

63

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Derivative Assets	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	34	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Noncurrent	1		—		1		1		—		—		—		—
Total Derivative Assets – Commodity Contracts	$	35	$	2	$	3	$	2	$	1	$	1	$	27	$	2
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	1	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	15		—		—		—		—		—		—		—
Total Derivative Assets – Interest Rate Contracts	$	16	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Total Derivative Assets	$	51	$	2	$	3	$	2	$	1	$	1	$	27	$	2

Derivative Liabilities	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	36	$	6	$	18	$	8	$	10	$	—	$	—	$	11
Noncurrent	146		4		10		4		—		—		—		131
Total Derivative Liabilities – Commodity Contracts	$	182	$	10	$	28	$	12	$	10	$	—	$	—	$	142
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	29	$	25	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	6		—		—		—		—		—		—		—
Not Designated as Hedging Instruments
Current	1		—		1		—		—		1		—		—
Noncurrent	12		—		7		6		2		4		—		—
Total Derivative Liabilities – Interest Rate Contracts	$	48	$	25	$	8	$	6	$	2	$	5	$	—	$	—
Total Derivative Liabilities	$	230	$	35	$	36	$	18	$	12	$	5	$	—	$	142

OFFSETTING ASSETS AND LIABILITIES

The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.

64

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Derivative Assets	March 31, 2018
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	15		$	2		$	3		$	2		$	1	$	1	$	7	$	1
Gross amounts offset	(2		)	(1		)	(1		)	(1		)	—		—		—		—
Net amounts presented in Current Assets: Other	$	13		$	1		$	2		$	1		$	1	$	1	$	7	$	1
Noncurrent
Gross amounts recognized	$	22		$	—		$	—		$	—		$	—	$	—	$	—	$	—
Gross amounts offset	—			—			—			—			—		—		—		—
Net amounts presented in Other Noncurrent Assets: Other	$	22		$	—		$	—		$	—		$	—	$	—	$	—	$	—

Derivative Liabilities	March 31, 2018
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	33		$	5		$	11		$	8		$	4	$	—	$	—	$	13
Gross amounts offset	(4		)	(2		)	(2		)	(2		)	—		—		—		—
Net amounts presented in Current Liabilities: Other	$	29		$	3		$	9		$	6		$	4	$	—	$	—	$	13
Noncurrent
Gross amounts recognized	$	157		$	6		$	26		$	13		$	3	$	4	$	—	$	119
Gross amounts offset	(1		)	—			(1		)	(1		)	—		—		—		—
Net amounts presented in Other Noncurrent Liabilities: Other	$	156		$	6		$	25		$	12		$	3	$	4	$	—	$	119

Derivative Assets	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	35	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Gross amounts offset	—		—		—		—		—		—		—		—
Net amounts presented in Current Assets: Other	$	35	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Noncurrent
Gross amounts recognized	$	16	$	—	$	1	$	1	$	—	$	—	$	—	$	—
Gross amounts offset	—		—		—		—		—		—		—		—
Net amounts presented in Other Noncurrent Assets: Other	$	16	$	—	$	1	$	1	$	—	$	—	$	—	$	—

65

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Derivative Liabilities	December 31, 2017
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	66		$	31		$	19		$	8		$	10	$	1	$	—	$	11
Gross amounts offset	(3		)	(2		)	(2		)	(2		)	—		—		—		—
Net amounts presented in Current Liabilities: Other	$	63		$	29		$	17		$	6		$	10	$	1	$	—	$	11
Noncurrent
Gross amounts recognized	$	164		$	4		$	17		$	10		$	2	$	4	$	—	$	131
Gross amounts offset	(1		)	—			(1		)	(1		)	—		—		—		—
Net amounts presented in Other Noncurrent Liabilities: Other	$	163		$	4		$	16		$	9		$	2	$	4	$	—	$	131

OBJECTIVE CREDIT CONTINGENT FEATURES

Certain derivative contracts contain objective credit contingent features. These features include the requirement to post cash collateral or letters of credit if specific events occur, such as a credit rating downgrade below investment grade. The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk-related payment provisions.

	March 31, 2018
			Duke				Duke		Duke
	Duke		Energy		Progress		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida
Aggregate fair value of derivatives in a net liability position	$	30	$	10	$	20	$	18	$	2
Fair value of collateral already posted	—		—		—		—		—
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	30		10		20		18		2

	December 31, 2017
			Duke				Duke		Duke
	Duke		Energy		Progress		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida
Aggregate fair value of derivatives in a net liability position	$	59	$	35	$	25	$	15	$	10
Fair value of collateral already posted	—		—		—		—		—
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	59		35		25		15		10

The Duke Energy Registrants have elected to offset cash collateral and fair values of derivatives. For amounts to be netted, the derivative and cash collateral must be executed with the same counterparty under the same master netting arrangement.

9.INVESTMENTS IN DEBT AND EQUITY SECURITIES

Duke Energy’s investments in debt and equity securities are primarily comprised of investments held in (i) the nuclear decommissioning trust fund (NDTF) at Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, (ii) grantor trusts at Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana related to Other Post-Retirement Benefit Obligations (OPEB) plans and (iii) Bison. The Duke Energy Registrants classify investments in debt securities as available-for-sale (AFS) and investments in equity securities as fair value through net income (FV-NI). 

For investments in debt securities classified as AFS, the unrealized gains and losses are included in other comprehensive income until realized, at which time, they are reported through net income. For investments in equity securities classified as FV-NI, both realized and unrealized gains and losses are reported through net income. Substantially all of Duke Energy’s investments in debt and equity securities qualify for regulatory accounting, and accordingly, all associated realized and unrealized gains and losses on these investments are deferred as a regulatory asset or liability.

Duke Energy classifies the majority of investments in debt and equity securities as long term, unless otherwise noted.

66

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Investment Trusts

The investments within the NDTF investments and the Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana grantor trusts (Investment Trusts) are managed by independent investment managers with discretion to buy, sell and invest pursuant to the objectives set forth by the trust agreements. The Duke Energy Registrants have limited oversight of the day-to-day management of these investments. As a result, the ability to hold investments in unrealized loss positions is outside the control of the Duke Energy Registrants. Accordingly, all unrealized losses associated with debt securities within the Investment Trusts are considered OTTIs and are recognized immediately and deferred to regulatory accounts where appropriate.

Other AFS Securities

Unrealized gains and losses on all other AFS securities are included in other comprehensive income until realized, unless it is determined the carrying value of an investment is other-than-temporarily impaired. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value should be considered other-than-temporary. If an OTTI exists, the unrealized credit loss is included in earnings. There were no material credit losses as of March 31, 2018, and December 31, 2017.

Other Investments amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

DUKE ENERGY

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	143	$	—	$	—	$	115
Equity securities	2,751		38		4,857		2,805		27		4,914
Corporate debt securities	7		8		549		17		2		570
Municipal bonds	1		5		333		4		3		344
U.S. government bonds	6		18		1,014		11		7		1,027
Other debt securities	—		2		130		—		1		118
Total NDTF Investments	$	2,765	$	71	$	7,026	$	2,837	$	40	$	7,088
Other Investments
Cash and cash equivalents	$	—	$	—	$	15	$	—	$	—	$	15
Equity securities	57		—		130		59		—		123
Corporate debt securities	—		1		64		1		—		57
Municipal bonds	1		1		80		2		1		83
U.S. government bonds	—		1		51		—		—		41
Other debt securities	—		—		48		—		1		44
Total Other Investments	$	58	$	3	$	388	$	62	$	2	$	363
Total Investments	$	2,823	$	74	$	7,414	$	2,899	$	42	$	7,451

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	100
Due after one through five years	535
Due after five through 10 years	530
Due after 10 years	1,104
Total	$	2,269

67

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	19
Realized losses	13
AFS:
Realized gains	5
Realized losses	13

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	93
Realized losses	62

DUKE ENERGY CAROLINAS

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	32
Equity securities	1,502		20		2,669		1,531		12		2,692
Corporate debt securities	3		5		333		9		2		359
Municipal bonds	—		1		69		—		1		60
U.S. government bonds	2		11		494		3		4		503
Other debt securities	—		2		122		—		1		112
Total NDTF Investments	$	1,507	$	39	$	3,737	$	1,543	$	20	$	3,758

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	11
Due after one through five years	178
Due after five through 10 years	285
Due after 10 years	544
Total	$	1,018

68

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	10
Realized losses	5
AFS:
Realized gains	5
Realized losses	10

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	66
Realized losses	40

PROGRESS ENERGY

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	93	$	—	$	—	$	83
Equity securities	1,249		18		2,188		1,274		15		2,222
Corporate debt securities	4		3		216		8		—		211
Municipal bonds	1		4		264		4		2		284
U.S. government bonds	4		7		520		8		3		524
Other debt securities	—		—		8		—		—		6
Total NDTF Investments	$	1,258	$	32	$	3,289	$	1,294	$	20	$	3,330
Other Investments
Cash and cash equivalents	$	—	$	—	$	10	$	—	$	—	$	12
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	57	$	2	$	—	$	59
Total Investments	$	1,259	$	32	$	3,346	$	1,296	$	20	$	3,389

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	75
Due after one through five years	300
Due after five through 10 years	198
Due after 10 years	482
Total	$	1,055

69

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	9
Realized losses	8
AFS:
Realized losses	3

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	27
Realized losses	21

DUKE ENERGY PROGRESS

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	59	$	—	$	—	$	50
Equity securities	959		14		1,765		980		12		1,795
Corporate debt securities	3		2		153		6		—		149
Municipal bonds	1		4		263		4		2		283
U.S. government bonds	3		5		326		5		2		310
Other debt securities	—		—		5		—		—		4
Total NDTF Investments	$	966	$	25	$	2,571	$	995	$	16	$	2,591
Other Investments
Cash and cash equivalents	$	—	$	—	$	1	$	—	$	—	$	1
Total Other Investments	$	—	$	—	$	1	$	—	$	—	$	1
Total Investments	$	966	$	25	$	2,572	$	995	$	16	$	2,592

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	19
Due after one through five years	216
Due after five through 10 years	144
Due after 10 years	368
Total	$	747

70

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	8
Realized losses	8
AFS:
Realized losses	2

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	24
Realized losses	19

DUKE ENERGY FLORIDA

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	34	$	—	$	—	$	33
Equity securities	290		4		423		294		3		427
Corporate debt securities	1		1		63		2		—		62
Municipal bonds	—		—		1		—		—		1
U.S. government bonds	1		2		194		3		1		214
Other debt securities	—		—		3		—		—		2
Total NDTF Investments(b)	$	292	$	7	$	718	$	299	$	4	$	739
Other Investments
Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	47	$	2	$	—	$	48
Total Investments	$	293	$	7	$	765	$	301	$	4	$	787

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

(b) During the three months endedMarch 31, 2018, Duke Energy Florida continued to receive reimbursements from the NDTF for costs related to ongoing decommissioning activity of the Crystal River Unit 3 nuclear plant.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	56
Due after one through five years	84
Due after five through 10 years	54
Due after 10 years	114
Total	$	308

71

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	1
AFS:
Realized losses	1

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	3
Realized losses	2

DUKE ENERGY INDIANA

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
Investments
Equity securities	$	48	$	—	$	96	$	49	$	—	$	97
Corporate debt securities	—		—		5		—		—		3
Municipal bonds	—		1		26		—		1		28
Total Investments	$	48	$	1	$	127	$	49	$	1	$	128

(a) Realized and unrealized gains and losses where regulatory accounting is applied are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	3
Due after one through five years	15
Due after five through 10 years	6
Due after 10 years	7
Total	$	31

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018, and from sales of AFS securities for the three months ended March 31, 2017, were insignificant.

10. FAIR VALUE MEASUREMENTS

Fair value is the exchange price to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. The fair value definition focuses on an exit price versus the acquisition cost. Fair value measurements use market data or assumptions market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs may be readily observable, corroborated by market data or generally unobservable. Valuation techniques maximize the use of observable inputs and minimize use of unobservable inputs. A midmarket pricing convention (the midpoint price between bid and ask prices) is permitted for use as a practical expedient.

Fair value measurements are classified in three levels based on the fair value hierarchy:

Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. An active market is one in which transactions for an asset or liability occur with sufficient frequency and volume to provide ongoing pricing information.

72

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Level 2 – A fair value measurement utilizing inputs other than quoted prices included in Level 1 that are observable, either directly or indirectly, for an asset or liability. Inputs include (i) quoted prices for similar assets or liabilities in active markets, (ii) quoted prices for identical or similar assets or liabilities in markets that are not active and (iii) inputs other than quoted market prices that are observable for the asset or liability, such as interest rate curves and yield curves observable at commonly quoted intervals, volatilities and credit spreads. A Level 2 measurement cannot have more than an insignificant portion of its valuation based on unobservable inputs. Instruments in this category include non-exchange-traded derivatives, such as over-the-counter forwards, swaps and options; certain marketable debt securities; and financial instruments traded in less-than-active markets.

Level 3 – Any fair value measurement that includes unobservable inputs for more than an insignificant portion of the valuation. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value. Level 3 measurements may include longer-term instruments that extend into periods in which observable inputs are not available.

Not Categorized – Certain investments are not categorized within the Fair Value hierarchy. These investments are measured at fair value using the net asset value (NAV) per share practical expedient. The NAV is derived based on the investment cost, less any impairment, plus or minus changes resulting from observable price changes for an identical or similar investment of the same issuer.

Fair value accounting guidance permits entities to elect to measure certain financial instruments that are not required to be accounted for at fair value, such as equity method investments or the company’s own debt, at fair value. The Duke Energy Registrants have not elected to record any of these items at fair value.

Transfers between levels represent assets or liabilities that were previously (i) categorized at a higher level for which the inputs to the estimate became less observable or (ii) classified at a lower level for which the inputs became more observable during the period. The Duke Energy Registrant’s policy is to recognize transfers between levels of the fair value hierarchy at the end of the period. There were no transfers between levels during the three months endedMarch 31, 2018, and 2017.

Valuation methods of the primary fair value measurements disclosed below are as follows.

Investments in equity securities

The majority of investments in equity securities are valued using Level 1 measurements. Investments in equity securities are typically valued at the closing price in the principal active market as of the last business day of the quarter. Principal active markets for equity prices include published exchanges such as New York Stock Exchange and Nasdaq Stock Market. Foreign equity prices are translated from their trading currency using the currency exchange rate in effect at the close of the principal active market. There was no after-hours market activity that was required to be reflected in the reported fair value measurements.

Investments in debt securities

Most investments in debt securities are valued using Level 2 measurements because the valuations use interest rate curves and credit spreads applied to the terms of the debt instrument (maturity and coupon interest rate) and consider the counterparty credit rating. If the market for a particular fixed-income security is relatively inactive or illiquid, the measurement is Level 3.

Commodity derivatives

Commodity derivatives with clearinghouses are classified as Level 1. Other commodity derivatives, including Piedmont's natural gas supply contracts, are primarily valued using internally developed discounted cash flow models that incorporate forward price, adjustments for liquidity (bid-ask spread) and credit or non-performance risk (after reflecting credit enhancements such as collateral), and are discounted to present value. Pricing inputs are derived from published exchange transaction prices and other observable data sources. In the absence of an active market, the last available price may be used. If forward price curves are not observable for the full term of the contract and the unobservable period had more than an insignificant impact on the valuation, the commodity derivative is classified as Level 3. In isolation, increases (decreases) in natural gas forward prices result in favorable (unfavorable) fair value adjustments for natural gas purchase contracts; and increases (decreases) in electricity forward prices result in unfavorable (favorable) fair value adjustments for electricity sales contracts. Duke Energy regularly evaluates and validates pricing inputs used to estimate the fair value of natural gas commodity contracts by a market participant price verification procedure. This procedure provides a comparison of internal forward commodity curves to market participant generated curves.

Interest rate derivatives

Most over-the-counter interest rate contract derivatives are valued using financial models that utilize observable inputs for similar instruments and are classified as Level 2. Inputs include forward interest rate curves, notional amounts, interest rates and credit quality of the counterparties.

Other fair value considerations

See Note 11 in Duke Energy's Annual Report on Form 10-K/A for the year ended December 31, 2017, for a discussion of the valuation of goodwill and intangible assets.

73

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

DUKE ENERGY

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the tables below for all Duke Energy Registrants exclude cash collateral, which is disclosed in Note 8. See Note 9 for additional information related to investments by major security type for the Duke Energy Registrants.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2			Level 3			Not Categorized
NDTF equity securities	$	4,857		$	4,785		$	—		$	—		$	72
NDTF debt securities	2,169			633			1,536			—			—
Other equity securities	130			130			—			—			—
Other debt securities	258			66			192			—			—
Derivative assets	37			2			27			8			—
Total assets	7,451			5,616			1,755			8			72
Derivative liabilities	(190		)	(1		)	(57		)	(132		)	—
Net assets (liabilities)	$	7,261		$	5,615		$	1,698		$	(124	)	$	72

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2			Level 3			Not Categorized
NDTF equity securities	$	4,914		$	4,840		$	—		$	—		$	74
NDTF debt securities	2,174			635			1,539			—			—
Other equity securities	123			123			—			—			—
Other debt securities	241			57			184			—			—
Derivative assets	51			3			20			28			—
Total assets	7,503			5,658			1,743			28			74
Derivative liabilities	(230		)	(2		)	(86		)	(142		)	—
Net assets (liabilities)	$	7,273		$	5,656		$	1,657		$	(114	)	$	74

The following table provides reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Amounts included in earnings for derivatives are primarily included in Cost of natural gas on the Duke Energy Registrants' Condensed Consolidated Statements of Operations and Comprehensive Income. Amounts included in changes of net assets on the Duke Energy Registrants' Condensed Consolidated Balance Sheets are included in regulatory assets or liabilities. All derivative assets and liabilities are presented on a net basis.

	Three Months Ended March 31, 2018								Three Months Ended March 31, 2017
(in millions)	Investments		Derivatives (net)			Total			Investments		Derivatives (net)			Total
Balance at beginning of period	$	—	$	(114	)	$	(114	)	$	5	$	(166	)	$	(161	)
Purchases, sales, issuances and settlements:
Settlements	—		(14		)	(14		)	—		(9		)	(9		)
Total gains included on the Condensed Consolidated Balance Sheet	—		4			4			—		40			40
Balance at end of period	$	—	$	(124	)	$	(124	)	$	5	$	(135	)	$	(130	)

74

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

DUKE ENERGY CAROLINAS

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2			Not Categorized
NDTF equity securities	$	2,669		$	2,597		$	—		$	72
NDTF debt securities	1,068			209			859			—
Derivative assets	2			—			2			—
Total assets	3,739			2,806			861			72
Derivative liabilities	(11		)	(1		)	(10		)	—
Net assets	$	3,728		$	2,805		$	851		$	72

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2			Not Categorized
NDTF equity securities	$	2,692		$	2,618		$	—		$	74
NDTF debt securities	1,066			204			862			—
Derivative assets	2			—			2			—
Total assets	3,760			2,822			864			74
Derivative liabilities	(35		)	(1		)	(34		)	—
Net assets	$	3,725		$	2,821		$	830		$	74

PROGRESS ENERGY

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	2,188		$	2,188		$	—
NDTF debt securities	1,101			424			677
Other debt securities	57			10			47
Derivative assets	3			—			3
Total assets	3,349			2,622			727
Derivative liabilities	(37		)	(1		)	(36		)
Net assets	$	3,312		$	2,621		$	691

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	2,222		$	2,222		$	—
NDTF debt securities	1,108			431			677
Other debt securities	59			12			47
Derivative assets	3			1			2
Total assets	3,392			2,666			726
Derivative liabilities	(36		)	(1		)	(35		)
Net assets	$	3,356		$	2,665		$	691

75

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

DUKE ENERGY PROGRESS

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	1,765		$	1,765		$	—
NDTF debt securities	806			254			552
Other debt securities	1			1			—
Derivative assets	2			—			2
Total assets	2,574			2,020			554
Derivative liabilities	(21		)	(1		)	(20		)
Net assets	$	2,553		$	2,019		$	534

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	1,795		$	1,795		$	—
NDTF debt securities	796			243			553
Other debt securities	1			1			—
Derivative assets	2			1			1
Total assets	2,594			2,040			554
Derivative liabilities	(18		)	(1		)	(17		)
Net assets	$	2,576		$	2,039		$	537

DUKE ENERGY FLORIDA

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1		Level 2
NDTF equity securities	$	423		$	423	$	—
NDTF debt securities	295			170		125
Other debt securities	47			—		47
Derivative assets	1			—		1
Total assets	766			593		173
Derivative liabilities	(7		)	—		(7		)
Net assets	$	759		$	593	$	166

	December 31, 2017
(in millions)	Total Fair Value			Level 1		Level 2
NDTF equity securities	$	427		$	427	$	—
NDTF debt securities	312			188		124
Other debt securities	48			1		47
Derivative assets	1			—		1
Total assets	788			616		172
Derivative liabilities	(12		)	—		(12		)
Net assets	$	776		$	616	$	160

76

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

DUKE ENERGY OHIO

The following table provides recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018								December 31, 2017
(in millions)	Total Fair Value			Level 2			Level 3		Total Fair Value			Level 2			Level 3
Derivative assets	$	1		$	—		$	1	$	1		$	—		$	1
Derivative liabilities	(4		)	(4		)	—		(5		)	(5		)	—
Net (liabilities) assets	$	(3	)	$	(4	)	$	1	$	(4	)	$	(5	)	$	1

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018		2017
Balance at beginning of period	$	1	$	5
Purchases, sales, issuances and settlements:
Settlements	—		(1		)
Total losses included on the Condensed Consolidated Balance Sheet	—		(3		)
Balance at end of period	$	1	$	1

DUKE ENERGY INDIANA

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value		Level 1		Level 2		Level 3
Other equity securities	$	96	$	96	$	—	$	—
Other debt securities	31		—		31		—
Derivative assets	7		—		—		7
Total assets	134		96		31		7
Derivative liabilities	—		—		—		—
Net assets	$	134	$	96	$	31	$	7

	December 31, 2017
(in millions)	Total Fair Value		Level 1		Level 2		Level 3
Other equity securities	$	97	$	97	$	—	$	—
Other debt securities	31		—		31		—
Derivative assets	27		—		—		27
Total assets	155		97		31		27
Derivative liabilities	—		—		—		—
Net assets	$	155	$	97	$	31	$	27

77

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018			2017
Balance at beginning of period	$	27		$	16
Purchases, sales, issuances and settlements:
Settlements	(14		)	(7		)
Total (losses) gains included on the Condensed Consolidated Balance Sheet	(6		)	—
Balance at end of period	$	7		$	9

PIEDMONT

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1		Level 3
Derivative assets	$	1		$	1	$	—
Derivative liabilities	(132		)	—		(132		)
Net (liabilities) assets	$	(131	)	$	1	$	(132	)

	December 31, 2017
(in millions)	Total Fair Value			Level 1		Level 3
Other debt securities	$	1		$	1	$	—
Derivative assets	2			2		—
Total assets	3			3		—
Derivative liabilities	(142		)	—		(142		)
Net (liabilities) assets	$	(139	)	$	3	$	(142	)

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018			2017
Balance at beginning of period	$	(142	)	$	(187	)
Total gains and settlements	10			42
Balance at end of period	$	(132	)	$	(145	)

78

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

QUANTITATIVE INFORMATION ABOUT UNOBSERVABLE INPUTS

The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3.

	March 31, 2018
	Fair Value
Investment Type	(in millions)			Valuation Technique	Unobservable Input	Range
Duke Energy Ohio
Financial Transmission Rights (FTRs)	$	1		RTO auction pricing	FTR price – per megawatt-hour (MWh)	$	—		-	$	2.88
Duke Energy Indiana
FTRs	7			RTO auction pricing	FTR price – per MWh	(5.09		)	-	7.58
Piedmont
Natural gas contracts	(132		)	Discounted cash flow	Forward natural gas curves – price per million British thermal unit (MMBtu)	2.15			-	3.65
Duke Energy
Total Level 3 derivatives	$	(124	)

	December 31, 2017
	Fair Value
Investment Type	(in millions)			Valuation Technique	Unobservable Input	Range
Duke Energy Ohio
FTRs	$	1		RTO auction pricing	FTR price – per MWh	$	0.07		-	$	1.41
Duke Energy Indiana
FTRs	27			RTO auction pricing	FTR price – per MWh	(0.77		)	-	7.44
Piedmont
Natural gas contracts	(142		)	Discounted cash flow	Forward natural gas curves – price per MMBtu	2.10			-	2.88
Duke Energy
Total Level 3 derivatives	$	(114	)

OTHER FAIR VALUE DISCLOSURES

The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements.

	March 31, 2018				December 31, 2017
(in millions)	Book Value		Fair Value		Book Value		Fair Value
Duke Energy	$	52,981	$	54,383	$	52,279	$	55,331
Duke Energy Carolinas	10,694		11,556		10,103		11,372
Progress Energy	17,757		19,270		17,837		20,000
Duke Energy Progress	7,357		7,687		7,357		7,992
Duke Energy Florida	7,015		7,632		7,095		7,953
Duke Energy Ohio	2,067		2,217		2,067		2,249
Duke Energy Indiana	3,782		4,322		3,783		4,464
Piedmont	2,037		2,209		2,037		2,209

At both March 31, 2018, and December 31, 2017, fair value of cash and cash equivalents, accounts and notes receivable, accounts payable, notes payable and commercial paper, and nonrecourse notes payable of VIEs are not materially different from their carrying amounts because of the short-term nature of these instruments and/or because the stated rates approximate market rates.

11. VARIABLE INTEREST ENTITIES

A VIE is an entity that is evaluated for consolidation using more than a simple analysis of voting control. The analysis to determine whether an entity is a VIE considers contracts with an entity, credit support for an entity, the adequacy of the equity investment of an entity and the relationship of voting power to the amount of equity invested in an entity. This analysis is performed either upon the creation of a legal entity or upon the occurrence of an event requiring re-evaluation, such as a significant change in an entity’s assets or activities. A qualitative analysis of control determines the party that consolidates a VIE. This assessment is based on (i) what party has the power to direct the activities of the VIE that most significantly impact its economic performance and (ii) what party has rights to receive benefits or is obligated to absorb losses that could potentially be significant to the VIE. The analysis of the party that consolidates a VIE is a continual reassessment.

79

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

CONSOLIDATED VIEs

The obligations of the consolidated VIEs discussed in the following paragraphs are nonrecourse to the Duke Energy registrants. The registrants have no requirement to provide liquidity to, purchase assets of or guarantee performance of these VIEs unless noted in the following paragraphs.

No financial support was provided to any of the consolidated VIEs during the three months ended March 31, 2018, and the year ended December 31, 2017, or is expected to be provided in the future, that was not previously contractually required.

Receivables Financing – DERF / DEPR / DEFR

Duke Energy Receivables Finance Company, LLC (DERF), Duke Energy Progress Receivables, LLC (DEPR) and Duke Energy Florida Receivables, LLC (DEFR) are bankruptcy remote, special purpose subsidiaries of Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, respectively. DERF, DEPR and DEFR are wholly owned limited liability companies with separate legal existence from their parent companies, and their assets are not generally available to creditors of their parent companies. On a revolving basis, DERF, DEPR and DEFR buy certain accounts receivable arising from the sale of electricity and related services from their parent companies.

DERF, DEPR and DEFR borrow amounts under credit facilities to buy these receivables. Borrowing availability from the credit facilities is limited to the amount of qualified receivables purchased. The sole source of funds to satisfy the related debt obligations is cash collections from the receivables. Amounts borrowed under the credit facilities are reflected on the Condensed Consolidated Balance Sheets as Long-Term Debt.

The most significant activity that impacts the economic performance of DERF, DEPR and DEFR are the decisions made to manage delinquent receivables. Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida consolidate DERF, DEPR and DEFR, respectively, as they make those decisions.

Receivables Financing – CRC

CRC is a bankruptcy remote, special purpose entity indirectly owned by Duke Energy. On a revolving basis, CRC buys certain accounts receivable arising from the sale of electricity, natural gas and related services from Duke Energy Ohio and Duke Energy Indiana. CRC borrows amounts under a credit facility to buy the receivables from Duke Energy Ohio and Duke Energy Indiana. Borrowing availability from the credit facility is limited to the amount of qualified receivables sold to CRC. The sole source of funds to satisfy the related debt obligation is cash collections from the receivables. Amounts borrowed under the credit facility are reflected on Duke Energy's Condensed Consolidated Balance Sheets as Long-Term Debt.

The proceeds Duke Energy Ohio and Duke Energy Indiana receive from the sale of receivables to CRC are typically 75 percent cash and 25 percent in the form of a subordinated note from CRC. The subordinated note is a retained interest in the receivables sold. Depending on collection experience, additional equity infusions to CRC may be required by Duke Energy to maintain a minimum equity balance of $3 million.

CRC is considered a VIE because (i) equity capitalization is insufficient to support its operations, (ii) power to direct the activities that most significantly impact the economic performance of the entity are not performed by the equity holder and (iii) deficiencies in net worth of CRC are funded by Duke Energy. The most significant activities that impact the economic performance of CRC are decisions made to manage delinquent receivables. Duke Energy consolidates CRC as it makes these decisions. Neither Duke Energy Ohio nor Duke Energy Indiana consolidate CRC.

Receivables Financing – Credit Facilities

The following table summarizes the amounts and expiration dates of the credit facilities and associated restricted receivables described above.

	Duke Energy
			Duke Energy		Duke Energy		Duke Energy
			Carolinas		Progress		Florida
(in millions)	CRC		DERF		DEPR		DEFR
Expiration date	December 2020		December 2020		February 2021		April 2019		(a)
Credit facility amount	$	325	$	450	$	300	$	225
Amounts borrowed at March 31, 2018	325		450		300		225
Amounts borrowed at December 31, 2017	325		450		300		225
Restricted Receivables at March 31, 2018	504		634		497		313
Restricted Receivables at December 31, 2017	545		640		459		317

(a)    In April 2018, the credit facility was extended through April 2021.

Nuclear Asset-Recovery Bonds – DEFPF

Duke Energy Florida Project Finance, LLC (DEFPF) is a bankruptcy remote, wholly owned special purpose subsidiary of Duke Energy Florida. DEFPF was formed in 2016 for the sole purpose of issuing nuclear asset-recovery bonds to finance Duke Energy Florida's unrecovered regulatory asset related to Crystal River Unit 3.

80

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

In June 2016, DEFPF issued senior secured bonds and used the proceeds to acquire nuclear asset-recovery property from Duke Energy Florida. The nuclear asset-recovery property acquired includes the right to impose, bill, collect and adjust a non-bypassable nuclear asset-recovery charge from all Duke Energy Florida retail customers until the bonds are paid in full and all financing costs have been recovered. The nuclear asset-recovery bonds are secured by the nuclear asset-recovery property, and cash collections from the nuclear asset-recovery charges are the sole source of funds to satisfy the debt obligation. The bondholders have no recourse to Duke Energy Florida.

DEFPF is considered a VIE primarily because the equity capitalization is insufficient to support its operations. Duke Energy Florida has the power to direct the significant activities of the VIE as described above, and therefore Duke Energy Florida is considered the primary beneficiary and consolidates DEFPF.

The following table summarizes the impact of DEFPF on Duke Energy Florida's Condensed Consolidated Balance Sheets.

(in millions)	March 31, 2018		December 31, 2017
Receivables of VIEs	$	4	$	4
Regulatory Assets: Current	51		51
Current Assets: Other	13		40
Other Noncurrent Assets: Regulatory assets	1,082		1,091
Current Liabilities: Other	3		10
Current maturities of long-term debt	53		53
Long-Term Debt	1,136		1,164

Commercial Renewables

Certain of Duke Energy’s renewable energy facilities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. Assets are restricted and cannot be pledged as collateral or sold to third parties without prior approval of debt holders. The activities that most significantly impact the economic performance of these renewable energy facilities were decisions associated with siting, negotiating PPAs, engineering, procurement and construction and decisions associated with ongoing operations and maintenance-related activities. Duke Energy consolidates the entities as it is responsible for all of these decisions.

The table below presents material balances reported on Duke Energy's Condensed Consolidated Balance Sheets related to renewables VIEs.

(in millions)	March 31, 2018			December 31, 2017
Current Assets: Other	$	217		$	174
Property, plant and equipment, cost	4,017			3,923
Other Noncurrent Assets: Other	227			50
Accumulated depreciation and amortization	(626		)	(591		)
Current maturities of long-term debt	171			170
Long-Term Debt	1,700			1,700
Other Noncurrent Liabilities: Deferred income taxes	—			(148		)
Other Noncurrent Liabilities: Other	236			241

NON-CONSOLIDATED VIEs

The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets.

	March 31, 2018
	Duke Energy										Duke		Duke
	Pipeline			Commercial		Other					Energy		Energy
(in millions)	Investments			Renewables		VIEs		Total			Ohio		Indiana
Receivables from affiliated companies	$	—		$	—	$	—	$	—		$	65	$	86
Investments in equity method unconsolidated affiliates	723			183		45		951			—		—
Other noncurrent assets	17			—		—		17			—		—
Total assets	$	740		$	183	$	45	$	968		$	65	$	86
Taxes accrued	(29		)	—		—		(29		)	—		—
Other current liabilities	—			—		3		3			—		—
Deferred income taxes	32			—		—		32			—		—
Other noncurrent liabilities	8			—		12		20			—		—
Total liabilities	$	11		$	—	$	15	$	26		$	—	$	—
Net assets	$	729		$	183	$	30	$	942		$	65	$	86

81

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

	December 31, 2017
	Duke Energy										Duke		Duke
	Pipeline			Commercial		Other					Energy		Energy
(in millions)	Investments			Renewables		VIEs		Total			Ohio		Indiana
Receivables from affiliated companies	$	—		$	—	$	—	$	—		$	87	$	106
Investments in equity method unconsolidated affiliates	697			180		42		919			—		—
Other noncurrent assets	17			—		—		17			—		—
Total assets	$	714		$	180	$	42	$	936		$	87	$	106
Taxes accrued	(29		)	—		—		(29		)	—		—
Other current liabilities	—			—		4		4			—		—
Deferred income taxes	42			—		—		42			—		—
Other noncurrent liabilities	—			—		12		12			—		—
Total liabilities	$	13		$	—	$	16	$	29		$	—	$	—
Net assets	$	701		$	180	$	26	$	907		$	87	$	106

The Duke Energy Registrants are not aware of any situations where the maximum exposure to loss significantly exceeds the carrying values shown above except for the power purchase agreement with OVEC, which is discussed below, and various guarantees, some of which are reflected in the table above as Other noncurrent liabilities. For more information on various guarantees, refer to Note 4.

Pipeline Investments

Duke Energy has investments in various joint ventures with pipeline projects currently under construction. These entities are considered VIEs due to having insufficient equity to finance their own activities without subordinated financial support. Duke Energy does not have the power to direct the activities that most significantly impact the economic performance, the obligation to absorb losses or the right to receive benefits of these VIEs and therefore does not consolidate these entities.

The table below presents Duke Energy's ownership interest and investment balances in these joint ventures.

			VIE Investment Amount (in millions)
	Ownership		March 31,		December 31,
Entity Name	Interest		2018		2017
ACP	47	%	$	474	$	397
Sabal Trail	7.5	%	223		219
Constitution(a)	24	%	26		81
Total			$	723	$	697

(a) During the three months ended March 31, 2018, Duke Energy recorded an OTTI of $55 million related to Constitution within Equity in (losses) earnings of unconsolidated affiliates on Duke Energy's Condensed Consolidated Statements of Income. See Note 3 for additional information.

In 2017, ACP executed a $3.4 billion revolving credit facility with a stated maturity date of October 2021. Duke Energy entered into a guarantee agreement to support its share of the ACP revolving credit facility. Duke Energy's maximum exposure to loss under the terms of the guarantee is limited to 47 percent of the outstanding borrowings under the credit facility, which was $346 million as of March 31, 2018.

On April 30, 2018, Sabal Trail closed on a $1.5 billion offering of senior notes. The notes were issued in three tranches due in 2028, 2038 and 2048. Duke Energy received $112 million of net proceeds as a result of the offering. As a result of the financing, Sabal Trail has sufficient equity to finance its own activities without additional subordinated financial support from other parties and will no longer be considered a VIE.

Commercial Renewables

Duke Energy has investments in various renewable energy project entities. Some of these entities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. Duke Energy does not consolidate these VIEs because power to direct and control key activities is shared jointly by Duke Energy and other owners.

Other VIEs

Duke Energy holds a 50 percent equity interest in Pioneer Transmission, LLC (Pioneer). Pioneer is considered a VIE due to having insufficient equity to finance its own activities without subordinated financial support. The activities that most significantly impact Pioneer's economic performance are decisions related to the development of new transmission facilities. The power to direct these activities is jointly and equally shared by Duke Energy and the other joint venture partner, American Electric Power; therefore, Duke Energy does not consolidate Pioneer.

82

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

OVEC

Duke Energy Ohio’s 9 percent ownership interest in OVEC is considered a non-consolidated VIE due to OVEC having insufficient equity to finance its activities without subordinated financial support. As a counterparty to an inter-company power agreement (ICPA), Duke Energy Ohio has a contractual arrangement to receive entitlements to capacity and energy from OVEC’s power plants through June 2040 commensurate with its power participation ratio, which is equivalent to Duke Energy Ohio's ownership interest. Costs, including fuel, operating expenses, fixed costs, debt amortization and interest expense, are allocated to counterparties to the ICPA based on their power participation ratio. The value of the ICPA is subject to variability due to fluctuation in power prices and changes in OVEC's cost of business. Deterioration in the credit quality or bankruptcy of one or more parties to the ICPA could increase the costs of OVEC. On March 31, 2018, FirstEnergy Solutions (FES), a subsidiary of FirstEnergy and counterparty to the ICPA, filed for Chapter 11 bankruptcy. FES has a power participation ratio of 4.85 percent. Duke Energy Ohio cannot predict the impact of the bankruptcy on its OVEC interests. In addition, certain proposed environmental rulemaking could result in future increased cost allocations.

CRC

See discussion under Consolidated VIEs for additional information related to CRC.

Amounts included in Receivables from affiliated companies in the above table for Duke Energy Ohio and Duke Energy Indiana reflect their retained interest in receivables sold to CRC. These subordinated notes held by Duke Energy Ohio and Duke Energy Indiana are stated at fair value. Carrying values of retained interests are determined by allocating carrying value of the receivables between assets sold and interests retained based on relative fair value. The allocated bases of the subordinated notes are not materially different than their face value because (i) the receivables generally turn over in less than two months, (ii) credit losses are reasonably predictable due to the broad customer base and lack of significant concentration and (iii) the equity in CRC is subordinate to all retained interests and thus would absorb losses first. The hypothetical effect on fair value of the retained interests assuming both a 10 percent and a 20 percent unfavorable variation in credit losses or discount rates is not material due to the short turnover of receivables and historically low credit loss history. Interest accrues to Duke Energy Ohio and Duke Energy Indiana on the retained interests using the acceptable yield method. This method generally approximates the stated rate on the notes since the allocated basis and the face value are nearly equivalent. An impairment charge is recorded against the carrying value of both retained interests and purchased beneficial interest whenever it is determined that an OTTI has occurred.

Key assumptions used in estimating fair value are detailed in the following table.

	Duke Energy Ohio				Duke Energy Indiana
	2018		2017		2018		2017
Anticipated credit loss ratio	0.5	%	0.5	%	0.3	%	0.3	%
Discount rate	2.6	%	2.1	%	2.6	%	2.1	%
Receivable turnover rate	13.6	%	13.5	%	10.8	%	10.7	%

The following table shows the gross and net receivables sold.

	Duke Energy Ohio				Duke Energy Indiana
(in millions)	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
Receivables sold	$	249	$	273	$	297	$	312
Less: Retained interests	65		87		86		106
Net receivables sold	$	184	$	186	$	211	$	206

The following table shows sales and cash flows related to receivables sold.

	Duke Energy Ohio				Duke Energy Indiana
	Three Months Ended				Three Months Ended
	March 31,				March 31,
(in millions)	2018		2017		2018		2017
Sales
Receivables sold	$	567	$	533	$	694	$	664
Loss recognized on sale	3		2		3		3
Cash flows
Cash proceeds from receivables sold	$	585	$	559	$	711	$	693
Return received on retained interests	2		1		2		2

Cash flows from sales of receivables are reflected within Operating Activities on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Cash Flows.

83

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Collection fees received in connection with servicing transferred accounts receivable are included in Operation, maintenance and other on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Operations and Comprehensive Income. The loss recognized on sales of receivables is calculated monthly by multiplying receivables sold during the month by the required discount. The required discount is derived monthly utilizing a three-year weighted average formula that considers charge-off history, late charge history and turnover history on the sold receivables, as well as a component for the time value of money. The discount rate, or component for the time value of money, is the prior month-end LIBOR plus a fixed rate of 1.00 percent.

12. REVENUE

As described in Note 1, Duke Energy adopted Revenue from Contracts with Customers effective January 1, 2018, using the modified retrospective method of adoption which does not require restatement of prior year reported results. No cumulative effect adjustment was recorded as the vast majority of Duke Energy’s revenues are at-will and without a defined contractual term. Additionally, comparative disclosures for 2018 operating results with the previous revenue recognition rules are not applicable as Duke Energy’s revenue recognition has not materially changed as a result of the new standard.

Duke Energy recognizes revenue consistent with amounts billed under tariff offerings or at contractually agreed upon rates based on actual physical delivery of electric or natural gas service, including estimated volumes delivered when billings have not yet occurred. As such, the majority of Duke Energy’s revenues have fixed pricing based on the contractual terms of the published tariffs, with variability in expected cash flows attributable to the customer’s volumetric demand and ultimate quantities of energy or natural gas supplied and used during the billing period. The stand-alone selling price of related sales are designed to support recovery of prudently incurred costs and an appropriate return on invested assets and are primarily governed by published tariff rates or contractual agreements approved by relevant regulatory bodies. As described in Note 1, certain excise taxes and franchise fees levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis as part of revenues. Duke Energy elects to account for all other taxes net of revenues.

Performance obligations are satisfied over time as energy or natural gas is delivered and consumed with billings generally occurring monthly and related payments due within 30 days, depending on regulatory requirements. In no event does the timing between payment and delivery of the goods and services exceed one year. Using this output method for revenue recognition provides a faithful depiction of the transfer of electric and natural gas service as customers obtain control of the commodity and benefit from its use at delivery. Additionally, Duke Energy has an enforceable right to consideration for energy or natural gas delivered at any discrete point in time, and will recognize revenue at an amount that reflects the consideration to which Duke Energy is entitled for the energy or natural gas delivered.

As described above, the majority of Duke Energy’s tariff revenues are at-will and, as such, related contracts with customers have an expected duration of one year or less and will not have future performance obligations for disclosure. Additionally, other long-term revenue streams, including wholesale contracts, generally provide services that are part of a single performance obligation, the delivery of electricity or natural gas. As such, other than material fixed consideration under long-term contract, related disclosures for future performance obligations are also not applicable.

Duke Energy earns substantially all of its revenues through its reportable segments, Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables.

Electric Utilities and Infrastructure

Electric Utilities and Infrastructure earns the majority of its revenues through retail and wholesale electric service through the generation, transmission, distribution and sale of electricity. Duke Energy generally provides retail and wholesale electric service customers with their full electric load requirements or with supplemental load requirements when the customer has other sources of electricity.

Retail electric service is generally marketed throughout Duke Energy's electric service territory through standard service offers. The standard service offers are through tariffs determined by regulators in Duke Energy's regulated service territory. Each tariff, which is assigned to customers based on customer class, has multiple components such as an energy charge, a demand charge, a basic facilities charge, and applicable riders. Duke Energy considers each of these components to be aggregated into a single performance obligation for providing electric service, or in the case of distribution only customers in Duke Energy Ohio, for delivering electricity. Electricity is considered a single performance obligation satisfied over time consistent with the series guidance and is provided and consumed over the billing period (generally one month). Retail electric service is typically provided to at-will customers that can cancel service at any time, without a substantive penalty. Additionally, Duke Energy adheres to applicable regulatory requirements in each jurisdiction to ensure the collectability of amounts billed and appropriate mitigating procedures are followed when necessary. As such, revenue from contracts with customers for such contracts is equivalent to the electricity supplied and billed in that period (including estimated billings).

Wholesale electric service is generally provided under long-term contracts using cost-based pricing. FERC regulates costs that may be recovered from customers and the amount of return companies are permitted to earn. Wholesale contracts include both energy and demand charges. For full requirements contracts, Duke Energy considers both charges as a single performance obligation for providing integrated electric service. For contracts where energy and demand charges are considered separate performance obligations, energy and demand are each a distinct performance obligation under the series guidance and are satisfied as energy is delivered and stand-ready service is provided on a monthly basis. This service represents consumption over the billing period and revenue is recognized consistent with billings and unbilled estimates, which generally occur monthly. Contractual amounts owed are typically trued up annually based upon incurred costs in accordance with FERC published filings and the specific customer’s actual peak demand. Estimates of variable consideration related to potential additional billings or refunds owed are updated quarterly.

84

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The majority of wholesale revenues are full requirements contracts where the customers purchase the substantial majority of their energy needs and do not have a fixed quantity of contractually required energy or capacity. As such, related forecasted revenues are considered optional purchases. Supplemental requirements contracts that include contracted blocks of energy and capacity at contractually fixed prices have the following estimated remaining performance obligations:

	Remaining Performance Obligations
(in millions)	2018		2019		2020		2021		2022		Thereafter		Total
Progress Energy	$	69	$	112	$	121	$	80	$	82	$	81	$	545
Duke Energy Progress	7		9		9		9		9		18		61
Duke Energy Florida	62		103		112		71		73		63		484
Duke Energy Indiana	6		9		10		5		—		—		30

Revenues for block sales are recognized monthly as energy is delivered and stand-ready service is provided, consistent with invoiced amounts and unbilled estimates.

Gas Utilities and Infrastructure

Gas Utilities and Infrastructure earns its revenue through retail and wholesale natural gas service through the transportation, distribution and sale of natural gas. Duke Energy generally provides retail and wholesale natural gas service customers with all natural gas load requirements. Additionally, while natural gas can be stored, substantially all natural gas provided by Duke Energy is consumed by customers simultaneously with receipt of delivery.

Retail natural gas service is marketed throughout Duke Energy's natural gas service territory using published tariff rates. The tariff rates are established by regulators in Duke Energy's service territories. Each tariff, which is assigned to customers based on customer class, have multiple components, such as a commodity charge, demand charge, customer or monthly charge, and transportation costs. Duke Energy considers each of these components to be aggregated into a single performance obligation for providing natural gas service. For contracts where Duke Energy provides all of the customer’s natural gas needs, the delivery of natural gas is considered a single performance obligation satisfied over time, and revenue is recognized monthly based on billings and unbilled estimates as service is provided and the commodity is consumed over the billing period. Additionally, natural gas service is typically at-will and customers can cancel service at any time, without a substantive penalty. Duke Energy also adheres to applicable regulatory requirements to ensure the collectability of amounts billed and receivable and appropriate mitigating procedures are followed when necessary.

Certain long-term individually negotiated contracts exist to provide natural gas service. These contracts are regulated and approved by state commissions. The negotiated contracts have multiple components, including a natural gas and a demand charge, similar to retail natural gas contracts. Duke Energy considers each of these components to be a single performance obligation for providing natural gas service. This service represents consumption over the billing period, generally one month.

Fixed capacity payments under long-term contracts for the Gas segment include minimum margin contracts and supply arrangements with municipalities and power generation facilities. Revenues for related sales are recognized monthly as natural gas is delivered and stand-ready service is provided, consistent with invoiced amounts and unbilled estimates. Estimated remaining performance obligations are as follows:

	Remaining Performance Obligations
(in millions)	2018		2019		2020		2021		2022		Thereafter		Total
Piedmont	$	55	$	72	$	70	$	65	$	64	$	482	$	808

Commercial Renewables

Commercial Renewables earns the majority of its revenues through long-term PPAs and generally sells all of its wind and solar facility output, electricity and Renewable Energy Credits (RECs) to customers. The majority of these PPAs have historically been accounted for as leases. For PPAs that are not accounted for as leases, the delivery of electricity and the delivery of RECs are considered separate performance obligations.

The delivery of electricity is a performance obligation satisfied over time and represents generation and consumption of the electricity over the billing period, generally one month. The delivery of RECs is a performance obligation satisfied at a point in time and represents delivery of each REC generated by the wind or solar facility. The majority of self-generated RECs are bundled with energy in Duke Energy’s contracts and, as such, related revenues are recognized as energy is generated and delivered as that pattern is consistent with Duke Energy’s performance. Commercial Renewables recognizes revenue based on the energy generated and billed for the period, generally one month, at contractual rates (including estimated billings) according to the invoice practical expedient. Amounts are typically due within 30 days of invoice.

Other

The remainder of Duke Energy’s operations is presented as Other, which does not include material revenues from contracts with customers.

85

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

Disaggregated Revenues

For the Electric and Gas segments, revenue by customer class is most meaningful to Duke Energy as each respective customer class collectively represents unique customer expectations of service, generally has different energy and demand requirements, and operates under tailored, regulatory approved pricing structures. Additionally, each customer class is impacted differently by weather and a variety of economic factors including the level of population growth, economic investment, employment levels, and regulatory activities in each of Duke Energy’s jurisdictions. As such, analyzing revenues disaggregated by customer class allows Duke Energy to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. For the Commercial Renewables segment, the majority of revenues from contracts with customers are from selling all of the unit-contingent output at contractually defined pricing under long-term PPAs with consistent expectations regarding the timing and certainty of cash flows. Disaggregated revenues are presented as follows:

	Three Months Ended March 31, 2018
			Duke				Duke		Duke		Duke		Duke
(in millions)	Duke		Energy		Progress		Energy		Energy		Energy		Energy
By market or type of customer	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Electric Utilities and Infrastructure
Residential	$	2,350	$	781	$	1,112	$	516	$	595	$	180	$	278	$	—
General	1,375		472		631		299		333		96		178		—
Industrial	664		255		208		145		62		30		173		—
Wholesale	633		119		446		397		50		—		68		—
Other revenues	139		67		129		85		43		14		17		—
Total Electric Utilities and Infrastructure revenue from contracts with customers	$	5,161	$	1,694	$	2,526	$	1,442	$	1,083	$	320	$	714	$	—
Gas Utilities and Infrastructure
Residential	$	413	$	—	$	—	$	—	$	—	$	111	$	—	$	302
Commercial	201		—		—		—		—		49		—		152
Industrial	48		—		—		—		—		7		—		41
Power Generation	—		—		—		—		—		—		—		13
Other revenues	55		—		—		—		—		6		—		49
Total Gas Utilities and Infrastructure revenue from contracts with customers	$	717	$	—	$	—	$	—	$	—	$	173	$	—	$	557
Commercial Renewables
Revenue from contracts with customers	$	33	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Other
Revenue from contracts with customers	$	17	$	—	$	—	$	—	$	—	$	14	$	—	$	—
Total revenue from contracts with customers	$	5,928	$	1,694	$	2,526	$	1,442	$	1,083	$	507	$	714	$	557
Other revenue sources (a)	$	207	$	69	$	50	$	18	$	32	$	17	$	17	$	(4	)
Total revenues	$	6,135	$	1,763	$	2,576	$	1,460	$	1,115	$	524	$	731	$	553

(a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Piedmont has regulatory mechanisms that periodically provide rate adjustments to refund any over-collection or to recover any under-collection of margin.

IMPACT OF WEATHER AND THE TIMING OF BILLING PERIODS

Revenues and costs are influenced by seasonal weather patterns. Peak sales of electricity occur during the summer and winter months, which results in higher revenue and cash flows during these periods. By contrast, lower sales of electricity occur during the spring and fall, allowing for scheduled plant maintenance. Residential and general service customers are more impacted by weather than industrial customers. Estimated weather impacts are based on actual current period weather compared to normal weather conditions. Normal weather conditions are defined as the long-term average of actual historical weather conditions. Heating-degree days measure the variation in weather based on the extent the average daily temperature falls below a base temperature. Cooling-degree days measure the variation in weather based on the extent the average daily temperature rises above the base temperature. Each degree of temperature below the base temperature counts as one heating-degree day and each degree of temperature above the base temperature counts as one cooling-degree day.

86

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The estimated impact of weather on earnings for Electric Utilities and Infrastructure is based on the temperature variances from a normal condition and customers' historic usage patterns. The methodology used to estimate the impact of weather does not consider all variables that may impact customer response to weather conditions, such as humidity in the summer or wind chill in the winter. The precision of this estimate may also be impacted by applying long-term weather trends to shorter-term periods.

Gas Utilities and Infrastructure's costs and revenues are influenced by seasonal patterns due to peak natural gas sales occurring during the winter months as a result of space heating requirements. Residential customers are the most impacted by weather. There are certain regulatory mechanisms for the North Carolina, South Carolina, Tennessee, and Ohio service territories that normalize the margins collected from certain customer classes during the winter. In North Carolina, rate design provides protection from both weather and other usage variations such as conservation, while South Carolina and Tennessee revenues are adjusted solely based on weather. Ohio primarily employs a fixed charge each month regardless of the season and usage.

UNBILLED REVENUE

Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy or natural gas delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes, timing of rendering customer bills and meter reading schedules, and the impact of weather normalization or margin decoupling mechanisms.

Unbilled revenues are included within Receivables and Receivables of variable interest entities (VIEs) on the Condensed Consolidated Balance Sheets as shown in the following table.

(in millions)	March 31, 2018		December 31, 2017
Duke Energy	$	823	$	944
Duke Energy Carolinas	310		342
Progress Energy	237		228
Duke Energy Progress	167		143
Duke Energy Florida	70		85
Duke Energy Ohio	2		4
Duke Energy Indiana	24		21
Piedmont	45		86

Additionally, Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, CRC and accounts for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 11 for further information. These receivables for unbilled revenues are shown in the table below.

(in millions)	March 31, 2018		December 31, 2017
Duke Energy Ohio	$	67	$	104
Duke Energy Indiana	108		132

13. COMMON STOCK

Basic Earnings Per Share (EPS) is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the diluted weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as stock options and equity forward sale agreements, were exercised or settled. Duke Energy’s participating securities are restricted stock units that are entitled to dividends declared on Duke Energy common stock during the restricted stock unit’s vesting periods.

87

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted average number of common shares outstanding to the diluted weighted average number of common shares outstanding.

	Three Months Ended March 31,
(in millions, except per-share amounts)	2018		2017
Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities	$	619	$	715
Weighted average shares outstanding – basic	701		700
Weighted average shares outstanding – diluted	701		700
Earnings per share from continuing operations attributable to Duke Energy common stockholders
Basic	$	0.88	$	1.02
Diluted	$	0.88	$	1.02
Potentially dilutive items excluded from the calculation(a)	2		2
Dividends declared per common share	$	0.89	$	0.855

(a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met.

Equity Forwards

On February 20, 2018, Duke Energy filed a prospectus supplement and executed an Equity Distribution Agreement (the EDA) under which it may sell up to $1 billion of its common stock through an at-the-market offering program, including an equity forward sales component. The EDA was entered into with Wells Fargo Securities, LLC, Citigroup Global Markets Inc., and J.P. Morgan Securities LLC (the Agents). Under the terms of the EDA, Duke Energy may issue and sell, through either of the Agents, shares of common stock through September 23, 2019. There were no transactions under the EDA during the three months ended March 31, 2018.

Separately, in March 2018, Duke Energy marketed an equity offering of 21.3 million shares of common stock through an Underwriting Agreement with Credit Suisse Securities (USA) LLC, J.P. Morgan Securities LLC, Barclays Capital Inc. and Goldman Sachs & Co. LLC, as representatives of several underwriters, Credit Suisse Capital LLC and J.P. Morgan Securities LLC as Forward Sellers, and Credit Suisse Capital LLC and JPMorgan Chase National Bank Associate, acting as forward purchasers. In connection with the offering, Duke Energy entered into equity forward sale agreements with Credit Suisse Securities (USA) LLC as Agent for Credit Suisse Capital LLC and J.P. Morgan Chase Bank, National Association. No amounts have or will be recorded in Duke Energy's Condensed Consolidated Financial Statements with respect to the equity offering until settlements of the Equity Forwards occur, which is expected by December 31, 2018. The Equity Forwards require Duke Energy to either physically settle the transactions by issuing 21.3 million shares in exchange for net proceeds at the then-applicable forward sale price specified by the agreements (initially $74.07 per share), or net settle in whole or in part through the delivery or receipt of cash or shares. If Duke Energy had elected to net share settle the contract as of March 31, 2018, Duke Energy would have been required to deliver 0.9 million shares. The initial forward sale price will be subject to adjustment on a daily basis based on a floating interest rate factor and will decrease by other fixed amounts specified in the relevant forward sale agreement. Until settlement of the Equity Forwards, earnings per share dilution resulting from the agreements, if any, will be determined under the treasury stock method. Share dilution occurs when the average market price of Duke Energy's stock is higher than the average forward sales price.

14. STOCK-BASED COMPENSATION

For employee awards, equity classified stock-based compensation cost is measured at the service inception date or the grant date, based on the estimated achievement of certain performance metrics or the fair value of the award, and is recognized as expense or capitalized as a component of property, plant and equipment over the requisite service period.

Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense and stock-based compensation costs capitalized are included in the following table.

	Three Months Ended
	March 31,
(in millions)	2018		2017
Restricted stock unit awards	$	10	$	8
Performance awards	7		7
Pretax stock-based compensation cost	$	17	$	15
Tax benefit associated with stock-based compensation expense	$	4	$	5
Stock-based compensation costs capitalized	1		1

88

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

15. EMPLOYEE BENEFIT PLANS

DEFINED BENEFIT RETIREMENT PLANS

Duke Energy maintains, and the Subsidiary Registrants participate in, qualified and non-qualified, non-contributory defined benefit retirement plans. Duke Energy’s policy is to fund amounts on an actuarial basis to provide assets sufficient to meet benefit payments to be paid to plan participants. The following table includes information related to the Duke Energy Registrants' contributions to its qualified defined benefit pension plans.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Total anticipated 2018 contributions	$	148	$	46	$	45	$	25	$	20	$	—	$	8	$	7
Contributions made during the three months ended March 31, 2018	141		46		45		25		20		—		8		—
Remaining estimated 2018 contributions	$	7	$	—	$	—	$	—	$	—	$	—	$	—	$	7

Duke Energy did not make any contributions to its qualified defined benefit pension plans during the three months ended March 31, 2017.

Duke Energy uses a December 31 measurement date for its defined benefit retirement plan assets and obligations.

Components of Net Periodic Benefit Costs

The tables below present total net periodic benefit costs prior to capitalization of amounts reflected as Net property, plant and equipment on the Condensed Consolidated Balance Sheets. Only the service cost component of net periodic benefit costs is eligible to be capitalized. The remaining non-capitalized portions of net periodic benefit costs are classified as either: (1) service cost, which is recorded in Operations, maintenance and other on the Condensed Consolidated Statements of Operations; or as (2) components of non-service cost, which is recorded in Other income and expenses, net on the Condensed Consolidated Statements of Operations. See Note 1 for further information on impacts of the retirement benefits accounting standard adopted by Duke Energy on January 1, 2018.

Pension and other post-retirement benefit costs presented in the tables below for the Subsidiary Registrants are amounts allocated from Duke Energy for the employees of the respective Subsidiary Registrants. The Condensed Consolidated Statements of Operations of the Subsidiary Registrants also include allocated net periodic benefit costs for their proportionate share of pension and post-retirement benefit costs related to employees of the Duke Energy shared services affiliate. However, in the tables below these amounts are only presented in the Duke Energy column. For additional information on the corporate governance and shared service expenses allocated from the Duke Energy shared service affiliate, see Note 7.

QUALIFIED PENSION PLANS

The following tables include the components of net periodic pension costs for qualified pension plans.

	Three Months Ended March 31, 2018
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	45		$	15		$	13		$	7		$	5		$	1		$	2		$	2
Interest cost on projected benefit obligation	75			18			24			11			13			5			6			3
Expected return on plan assets	(140		)	(37		)	(45		)	(21		)	(23		)	(7		)	(10		)	(6		)
Amortization of actuarial loss	33			7			11			5			6			1			2			3
Amortization of prior service credit	(8		)	(2		)	(1		)	—			—			—			—			(3		)
Net periodic pension costs	$	5		$	1		$	2		$	2		$	1		$	—		$	—		$	(1	)

	Three Months Ended March 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	40		$	12		$	12		$	6		$	5		$	1		$	2		$	3
Interest cost on projected benefit obligation	82			20			25			12			13			5			7			3
Expected return on plan assets	(136		)	(35		)	(43		)	(21		)	(21		)	(7		)	(11		)	(6		)
Amortization of actuarial loss	36			8			14			6			7			1			3			3
Amortization of prior service credit	(6		)	(2		)	(1		)	—			—			—			—			(1		)
Other	2			—			1			—			—			—			—			—
Net periodic pension costs	$	18		$	3		$	8		$	3		$	4		$	—		$	1		$	2

89

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

NON-QUALIFIED PENSION PLANS

Net periodic pension costs for non-qualified pension plans were not material for the three months ended March 31, 2018 and 2017.

OTHER POST-RETIREMENT BENEFIT PLANS

Duke Energy provides, and the Subsidiary Registrants participate in, some health care and life insurance benefits for retired employees on a contributory and non-contributory basis.

The following tables include the components of net periodic other post-retirement benefit costs.

	Three Months Ended March 31, 2018
				Duke						Duke		Duke			Duke		Duke
	Duke			Energy			Progress			Energy		Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress		Florida			Ohio		Indiana		Piedmont
Service cost	$	1		$	—		$	—		$	—	$	—		$	—	$	—	$	—
Interest cost on accumulated post-retirement benefit obligation	7			2			4			1		1			—		1		—
Expected return on plan assets	(2		)	(2		)	—			—		—			—		—		—
Amortization of actuarial loss	1			—			—			—		—			—		1		—
Amortization of prior service credit	(5		)	(1		)	(2		)	—		(1		)	—		—		—
Net periodic other post-retirement benefit costs	$	2		$	(1	)	$	2		$	1	$	—		$	—	$	2	$	—

	Three Months Ended March 31, 2017
				Duke						Duke			Duke			Duke		Duke
	Duke			Energy			Progress			Energy			Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio		Indiana		Piedmont
Service cost	$	1		$	—		$	—		$	—		$	—		$	—	$	—	$	—
Interest cost on accumulated post-retirement benefit obligation	9			2			4			2			2			—		—		—
Expected return on plan assets	(3		)	(2		)	—			—			—			—		—		—
Amortization of actuarial loss (gain)	2			(1		)	5			3			2			—		—		—
Amortization of prior service credit	(29		)	(2		)	(21		)	(14		)	(8		)	—		—		—
Net periodic other post-retirement benefit costs	$	(20	)	$	(3	)	$	(12	)	$	(9	)	$	(4	)	$	—	$	—	$	—

EMPLOYEE SAVINGS PLAN

Duke Energy sponsors, and the Subsidiary Registrants participate in, an employee savings plan that covers substantially all employees. The following table includes employer contributions made by Duke Energy and expensed by the Subsidiary Registrants.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Three Months Ended March 31,
2018	$	70	$	23	$	19	$	13	$	6	$	1	$	3	$	4
2017	65		22		18		13		5		1		3		2

90

PART I

DUKE ENERGY CORPORATION – DUKE ENERGY CAROLINAS, LLC – PROGRESS ENERGY, INC. –

DUKE ENERGY PROGRESS, LLC – DUKE ENERGY FLORIDA, LLC – DUKE ENERGY OHIO, INC. – DUKE ENERGY INDIANA, LLC – PIEDMONT NATURAL GAS COMPANY, INC.

Combined Notes to Condensed Consolidated Financial Statements – (Unaudited) – (Continued)

16. INCOME TAXES

Tax Act

On December 22, 2017, President Trump signed the Tax Act into law. Among other provisions, the Tax Act lowered the corporate federal income tax rate from 35 percent to 21 percent, limits interest deductions outside of regulated utility operations, requires the normalization of excess deferred taxes associated with property under the average rate assumption method as a prerequisite to qualifying for accelerated depreciation and repealed the federal manufacturing deduction. The Tax Act also repealed the corporate alternative minimum tax (AMT) and stipulates a refund of 50 percent of remaining AMT credit carryforwards (to the extent the credits exceed regular tax for the year) for tax years 2018, 2019 and 2020 with all remaining AMT credits to be refunded in tax year 2021.

At this time, AMT credits that are treated as refundable under the Tax Act are among the certain refundable tax credits that are subject to sequestration. During the three months ended March 31, 2018, the company has revised the December 31, 2017, estimate of the income tax effects of the Tax Act by recording a $76 million valuation allowance against these AMT credits based on additional interpretative guidance from the Internal Revenue Service related to the Tax Act. See Note 22 to the Consolidated Financial Statements in the Annual Report on Form 10-K/A for the year ended December 31, 2017, for information on the U.S. Securities and Exchange Commission staff's guidance on accounting for the Tax Act (Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act).

EFFECTIVE TAX RATES

The effective tax rates from continuing operations for each of the Duke Energy Registrants are included in the following table.

	Three Months Ended
	March 31,
	2018		2017
Duke Energy	22.5	%	32.4	%
Duke Energy Carolinas	22.0	%	35.4	%
Progress Energy	13.2	%	34.1	%
Duke Energy Progress	14.1	%	34.1	%
Duke Energy Florida	16.3	%	36.6	%
Duke Energy Ohio	32.4	%	35.4	%
Duke Energy Indiana	25.9	%	39.3	%
Piedmont	24.1	%	37.9	%

The decrease in the effective tax rate (ETR) for Duke Energy and the Subsidiary Registrants for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act partially offset by a valuation allowance against AMT credits discussed above.

The decrease in the ETR for Duke Energy Carolinas for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act.

The decrease in the ETR for Progress Energy for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act and the amortization of federal and state excess deferred taxes.

The decrease in the ETR for Duke Energy Progress for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act and the amortization of state excess deferred taxes.

The decrease in the ETR for Duke Energy Florida for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act and the amortization of federal excess deferred taxes.

The decrease in the ETR for Duke Energy Ohio for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act partially offset by tax levelization related to federal excess deferred taxes on a pretax loss for the three months ended March 31, 2018.

The decrease in the ETR for Duke Energy Indiana for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act.

The decrease in the ETR for Piedmont for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act.

17. SUBSEQUENT EVENTS

For information on subsequent events related to regulatory matters, commitments and contingencies, debt and credit facilities and variable interest entities see Notes 3, 4, 5 and 11, respectively.

91

PART I

ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

The following combined Management’s Discussion and Analysis of Financial Condition and Results of Operations is separately filed by Duke Energy Corporation (collectively with its subsidiaries, Duke Energy) and Duke Energy Carolinas, LLC (Duke Energy Carolinas), Progress Energy, Inc. (Progress Energy), Duke Energy Progress, LLC (Duke Energy Progress), Duke Energy Florida, LLC (Duke Energy Florida), Duke Energy Ohio, Inc. (Duke Energy Ohio), Duke Energy Indiana, LLC (Duke Energy Indiana) and Piedmont Natural Gas Company, Inc. (Piedmont) (collectively referred to as the Subsidiary Registrants). However, none of the registrants make any representation as to information related solely to Duke Energy or the Subsidiary Registrants of Duke Energy other than itself.

DUKE ENERGY

Duke Energy is an energy company headquartered in Charlotte, North Carolina. Duke Energy operates in the United States (U.S.) primarily through its wholly owned subsidiaries, Duke Energy Carolinas, Duke Energy Progress, Duke Energy Florida, Duke Energy Ohio, Duke Energy Indiana and Piedmont. When discussing Duke Energy’s consolidated financial information, it necessarily includes the results of the Subsidiary Registrants, which, along with Duke Energy, are collectively referred to as the Duke Energy Registrants.

Management’s Discussion and Analysis should be read in conjunction with the Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018 and 2017 and with Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

Executive Overview

Regulatory Activity

In 2018, Duke Energy advanced regulatory activity underway in multiple jurisdictions, achieving several key milestones.

Duke Energy Progress received an order on its rate case from the North Carolina Utilities Commission on February 23, 2018. Some of the major components of the order are: a return on equity of 9.9 percent; recovery of past coal ash remediation costs; recovery of deferred storm costs from 2016; and new rates in effect mid-March 2018.

Duke Energy Kentucky received an order on its rate case from the Kentucky Public Service Commission on April 13, 2018. The order granted an annual revenue increase of $21 million, incorporating customer benefits from the Tax Cuts and Jobs Act (Tax Act) as well as rider recovery of environmental costs, including coal ash. Duke Energy Kentucky implemented new base rates on May 1, 2018.

Duke Energy Ohio along with the Public Utilities Commission of Ohio (PUCO) Staff and others filed a Stipulation and Recommendation (Stipulation) with PUCO on April 13, 2018. The Stipulation, subject to approval by PUCO, is in connection with Duke Energy Ohio's rate case and other regulatory matters.

Hearings commenced and were concluded in first quarter for Duke Energy Carolinas base rate case with the North Carolina Utilities Commission. The rate request was driven by capital investments in new, highly efficient natural gas combined-cycle plants and other plant upgrades, coal ash basin closure activities, grid improvement projects, and Lee Nuclear Station project costs. An order is expected by mid-year 2018.

See Note 3 to the Condensed Consolidated Financial Statements, "Regulatory Matters" for additional information.

Results of Operations

Non-GAAP Measures

Management’s Discussion and Analysis includes financial information prepared in accordance with generally accepted accounting principles (GAAP) in the U.S., as well as certain non-GAAP financial measures. Generally, a non-GAAP financial measure is a numerical measure of financial performance, financial position or cash flows that excludes (or includes) amounts that are included in (or excluded from) the most directly comparable measure calculated and presented in accordance with GAAP. Non-GAAP financial measures should be viewed as a supplement to, and not a substitute for, financial measures presented in accordance with GAAP. Non-GAAP measures presented may not be comparable to similarly titled measures used by other companies because other companies may not calculate the measures in the same manner.

Management evaluates financial performance in part based on non-GAAP financial measures, including adjusted earnings and adjusted diluted earnings per share (EPS). Adjusted earnings and adjusted diluted EPS represent income from continuing operations attributable to Duke Energy, adjusted for the dollar and per-share impact of special items. As discussed below, special items represent certain charges and credits, which management believes are not indicative of Duke Energy's ongoing performance.

Management believes the presentation of adjusted earnings and adjusted diluted EPS provides useful information to investors, as it provides them with an additional relevant comparison of Duke Energy’s performance across periods. Management uses these non-GAAP financial measures for planning and forecasting and for reporting financial results to the Duke Energy Board of Directors, employees, stockholders, analysts and investors. Adjusted diluted EPS is also used as a basis for employee incentive bonuses. The most directly comparable GAAP measures for adjusted earnings and adjusted diluted EPS are Net Income Attributable to Duke Energy Corporation (GAAP Reported Earnings) and Diluted EPS Attributable to Duke Energy Corporation common stockholders (GAAP Reported EPS), respectively.

Special items included in the periods presented include the following items, which management believes do not reflect ongoing costs:

• Costs to Achieve Piedmont Merger represent charges that result from the Piedmont acquisition.

• Regulatory Settlements represent costs related to rate case orders, settlements or other actions of regulators.

92

PART I

• Sale of Retired Plant represents the loss associated with selling Beckjord, a nonregulated generating facility in Ohio.

• Impairment of Equity Method Investment represents an other-than-temporary impairment (OTTI) of an investment in Constitution Pipeline Company, LLC.

• Impacts of the Tax Act represents an alternative minimum tax (AMT) valuation allowance recognized related to the Tax Act.

Reconciliation of GAAP Reported Amounts to Adjusted Amounts

The following table reconciles non-GAAP measures, including adjusted diluted EPS, to their most directly comparable GAAP measures.

	Three Months Ended March 31,
	2018				2017
(in millions, except per-share amounts)	Earnings		EPS		Earnings		EPS
GAAP Reported Earnings/GAAP Reported EPS	$	620	$	0.88	$	716	$	1.02
Adjustments:
Costs to Achieve Piedmont Merger(a)	13		0.02		10		0.02
Regulatory Settlements(b)	66		0.09		—		—
Sale of Retired Plant(c)	82		0.12		—		—
Impairment of Equity Method Investment(d)	42		0.06		—		—
Impacts of the Tax Act (AMT valuation allowance)	76		0.11		—		—
Adjusted Earnings/Adjusted Diluted EPS	$	899	$	1.28	$	726	$	1.04

(a) Net of $4 million tax benefit in 2018 and $6 million tax benefit in 2017.

(b) Net of $20 million tax benefit.

(c) Net of $25 million tax benefit.

(d) Net of $13 million tax benefit.

Three Months Ended March 31, 2018, as compared to March 31, 2017

GAAP Reported EPS was $0.88 for the first quarter of 2018 compared to $1.02 for the first quarter of 2017.

The decrease in GAAP Reported EPS was primarily due to the special items listed above as well as increased depreciation expense due to higher depreciable base, partially offset by the following variances in Electric Utilities and Infrastructure:

• Return to normal weather this year compared to the significantly warmer winter weather in the prior year;

• Higher retail revenues from increased volumes and pricing and riders due to increased investments; and

• Lower operation and maintenance expense driven by a Nuclear Electric Insurance Limited (NEIL) tax reform distribution, lower storm costs, receipt of a U.S. Department of Energy settlement and favorable timing across jurisdictions.

As discussed above, management also evaluates financial performance based on adjusted diluted EPS. Duke Energy’s first quarter 2018 adjusted diluted EPS was $1.28 compared to $1.04 for the first quarter of 2017.

SEGMENT RESULTS

The remaining information presented in this discussion of results of operations is on a GAAP basis. Management evaluates segment performance based on segment income. Segment income is defined as income from continuing operations net of income attributable to noncontrolling interests. Segment income includes intercompany revenues and expenses that are eliminated in the Condensed Consolidated Financial Statements.

Duke Energy's segment structure includes the following segments: Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables. The remainder of Duke Energy’s operations is presented as Other. See Note 2 to the Condensed Consolidated Financial Statements, “Business Segments,” for additional information on Duke Energy’s segment structure.

Tax Act

On December 22, 2017, President Trump signed the Tax Act into law. Among other provisions, the Tax Act lowered the corporate federal income tax rate from 35 percent to 21 percent, limits interest deductions outside of regulated utility operations, requires the normalization of excess deferred taxes associated with property under the average rate assumption method as a prerequisite to qualifying for accelerated depreciation and repealed the federal manufacturing deduction. The Tax Act also repealed the corporate AMT and stipulates a refund of 50 percent of remaining AMT credit carryforwards (to the extent the credits exceed regular tax for the year) for tax years 2018, 2019 and 2020 with all remaining AMT credits to be refunded in tax year 2021. The Tax Act also could be amended or subject to technical correction, which could change the financial impacts that were recorded since December 31, 2017, or are expected to be recorded in future periods. The FERC and state utility commissions will determine the regulatory treatment of the impacts of the Tax Act for the Subsidiary Registrants. Duke Energy's segments’ future results of operations, financial condition and cash flows could be adversely impacted by the Tax Act, subsequent amendments or corrections, or the actions of the FERC, state utility commissions or credit rating agencies related to the Tax Act. Duke Energy is addressing the rate treatment of the Tax Act by each state utility commission in which the Subsidiary Registrants operate. In January 2018, the Subsidiary Registrants began deferring the estimated ongoing impacts of the Tax Act that are expected to be returned to customers. See Note 16 to the Condensed Consolidated Financial Statements, “Income Taxes,” for additional information on the Tax Act. See the Credit Ratings section below for additional information on the impact of the Tax Act on the Duke Energy Registrants' credit ratings.

93

PART I

Electric Utilities and Infrastructure

	Three Months Ended March 31,
(in millions)	2018		2017		Variance
Operating Revenues	$	5,323	$	4,947	$	376
Operating Expenses
Fuel used in electric generation and purchased power	1,685		1,454		231
Operation, maintenance and other	1,325		1,304		21
Depreciation and amortization	835		737		98
Property and other taxes	274		261		13
Impairment charges	43		—		43
Total operating expenses	4,162		3,756		406
Gains on Sales of Other Assets and Other, net	1		3		(2		)
Operating Income	1,162		1,194		(32		)
Other Income and Expenses	88		112		(24		)
Interest Expense	317		315		2
Income Before Income Taxes	933		991		(58		)
Income Tax Expense	183		356		(173		)
Segment Income	$	750	$	635	$	115
Duke Energy Carolinas gigawatt-hours (GWh) sales	22,627		20,781		1,846
Duke Energy Progress GWh sales	17,226		15,637		1,589
Duke Energy Florida GWh sales	9,119		8,305		814
Duke Energy Ohio GWh sales	6,072		6,059		13
Duke Energy Indiana GWh sales	8,485		8,208		277
Total Electric Utilities and Infrastructure GWh sales	63,529		58,990		4,539
Net proportional megawatt (MW) capacity in operation	48,831		48,964		(133		)

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Electric Utilities and Infrastructure’s results were impacted by a return to normal weather this year compared to the significantly warmer winter weather in the prior year, higher weather-normal retail sales volumes and retail pricing, partially offset by impacts from the Tax Act. The following is a detailed discussion of the variance drivers by line item.

Operating Revenues. The variance was driven primarily by:

• a $225 million increase in fuel related revenues due to higher sales volumes and increases in fuel rates billed to customers;

• a $178 million increase in retail sales, net of fuel revenues, due to normal weather in the current year;

• a $24 million increase in weather-normal retail sales volumes;

• a $24 million increase in wholesale power revenues, net of sharing and fuel, primarily due to coal ash recovery at Duke Energy Carolinas and Duke Energy Progress, partially offset by customer refunds in the current year related to a FERC order on a complaint filed by the Piedmont Municipal Power Agency (PMPA) at Duke Energy Carolinas; and

• a $20 million increase in retail pricing due to the Duke Energy Progress North Carolina and South Carolina rate cases, and Duke Energy Florida base rate adjustments for the Osprey acquisition and the completion of the Hines Energy Complex Chiller Uprate Project.

Partially offset by:

• a $131 million decrease due to revenues subject to refund to customers associated with the lower statutory corporate tax rate under the Tax Act.

Operating Expenses. The variance was driven primarily by:

• a $231 million increase in fuel used in electric generation and purchased power due to higher sales and higher deferred fuel expenses;

• a $98 million increase in depreciation and amortization expense primarily due to additional plant in service, higher amortization of deferred coal ash costs and new depreciation rates per the Duke Energy Progress North Carolina rate case;

• a $43 million increase in impairment charges primarily due to the impacts associated with the Duke Energy Progress North Carolina rate case; and

94

PART I

• a $21 million increase in operation, maintenance and other expense primarily due to storm cost amortization, partially offset by lower expenses at generating plants.

Other Income and Expenses. The decrease was primarily due to lower allowance for funds used during construction (AFUDC) equity and a decrease in recognition of post in-service equity returns for projects that had been completed prior to being reflected in customer rates at Duke Energy Carolinas and lower income from non-service components of employee benefit costs in the current year at Duke Energy Progress. For additional information on employee benefit costs, see Note 15 to the Condensed Consolidated Financial Statements, "Employee Benefit Plans."

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The effective tax rates (ETRs) for the three months ended March 31, 2018, and 2017 were 19.6 percent and 35.9 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act and the amortization of excess deferred taxes. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Electric Utilities and Infrastructure Results

On May 18, 2016, the North Carolina Department of Environmental Quality (NCDEQ) issued proposed risk classifications for all coal ash surface impoundments in North Carolina. All ash impoundments not previously designated as high priority by the North Carolina Coal Ash Management Act of 2014 (Coal Ash Act) were designated as intermediate risk. Certain impoundments classified as intermediate risk, however, may be reassessed in the future as low risk pursuant to legislation enacted on July 14, 2016. Electric Utilities and Infrastructure's estimated asset retirement obligations (AROs) related to the closure of North Carolina ash impoundments are based upon the mandated closure method or a probability weighting of potential closure methods for the impoundments that may be reassessed to low risk. As the final risk ranking classifications in North Carolina are delineated, final closure plans and corrective action measures are developed and approved for each site, the closure work progresses and the closure method scope and remedial methods are determined, the complexity of work and the amount of coal combustion material could be different than originally estimated and, therefore, could materially impact Electric Utilities and Infrastructure's financial position.

On March 2, 2017, Duke Energy Ohio filed an electric distribution base rate application with the PUCO to address recovery of electric distribution system capital investments and any increase in expenditures subsequent to previous rate cases. On April 13, 2018, DEO along with the PUCO Staff and others filed a Stipulation with PUCO. The Stipulation is subject to approval by PUCO. Duke Energy Ohio's earnings could be adversely impacted if the Stipulation is denied by the PUCO. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

Duke Energy Carolinas filed a general rate case on August 25, 2017, to recover costs of complying with CCR regulations and the Coal Ash Act, as well as costs of capital investments in generation, transmission and distribution systems and any increase in expenditures subsequent to previous rate cases. Duke Energy Carolinas' earnings could be adversely impacted if the rate increase is delayed or denied by the NCUC. Hearings have concluded and a decision from the NCUC is expected by mid-2018. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

Duke Energy is a party to multiple lawsuits and could be subject to fines and other penalties related to operations at certain North Carolina facilities with ash basins. The outcome of these lawsuits and potential fines and penalties could have an adverse impact on Electric Utilities and Infrastructure's financial position, results of operations and cash flows. See Note 4 to the Condensed Consolidated Financial Statements, “Commitments and Contingencies,” for additional information.

Duke Energy Florida is constructing the 1,640-MW combined-cycle natural gas plant in Citrus County, Florida and expects it to be commercially available in 2018. Failure to complete the construction and achieve commercial operations by the end of 2018 could materially impact Duke Energy Florida’s financial position.

On February 6, 2018, the Florida Public Service Commission (FPSC) approved a stipulation that would apply tax savings resulting from the Tax Act toward storm costs effective January 2018 in lieu of implementing a storm surcharge. Storm costs are currently expected to be fully recovered by approximately mid-2021. The evidentiary hearing in this storm cost matter is scheduled for the week of October 15, 2018. An order disallowing recovery of these costs could have an adverse impact on Electric Utilities and Infrastructure's financial position. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

95

PART I

Gas Utilities and Infrastructure

	Three Months Ended March 31,
(in millions)	2018			2017		Variance
Operating Revenues	$	727		$	670	$	57
Operating Expenses
Cost of natural gas	313			258		55
Operation, maintenance and other	108			105		3
Depreciation and amortization	61			57		4
Property and other taxes	31			30		1
Total operating expenses	513			450		63
Operating Income	214			220		(6		)
Other Income and Expenses	(35		)	18		(53		)
Interest Expense	27			26		1
Income Before Income Taxes	152			212		(60		)
Income Tax Expense	36			79		(43		)
Segment Income	$	116		$	133	$	(17	)
Piedmont local distribution company (LDC) throughput (dekatherms)	154,901,379			133,276,787		21,624,592
Duke Energy Midwest LDC throughput (Mcf)	37,126,065			30,830,999		6,295,066

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Gas Utilities and Infrastructure’s results were primarily impacted by the OTTI recorded on the Constitution investment. The following is a detailed discussion of the variance drivers by line item.

Operating Revenues.The variance was driven by:

• a $54 million increase due to higher natural gas costs passed through to customers due to higher volumes sold and higher natural gas prices at Piedmont;

• a $22 million increase primarily due to residential and commercial customer revenue, net of natural gas costs passed through to customers, due to customer growth and Integrity Management Rider (IMR) rate adjustments at Piedmont; and

• a $10 million increase primarily due to favorable weather and higher volumes in the Midwest.

Partially offset by:

• a $29 million decrease due to revenues subject to refund to customers associated with the lower statutory corporate tax rates under the Tax Act.

Operating Expenses.The variance was driven by:

• a $55 million increase in cost of natural gas primarily due to higher volumes sold and higher natural gas prices at Piedmont.

Other Income and Expenses. The variance was driven by the OTTI recorded for the investment in Constitution in the current year.

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 23.7 percent and 37.3 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Gas Utilities and Infrastructure Results

Gas Utilities and Infrastructure has a 47 percent ownership interest in ACP, which is building an approximately 600-mile interstate natural gas pipeline intended to transport diverse natural gas supplies into southeastern markets. Affected states (West Virginia, Virginia and North Carolina) have issued certain necessary permits; the project remains subject to other pending federal and state approvals, which will allow full construction activities to begin. In early 2018, the FERC issued series of Partial Notices to Proceed, which authorized the project to begin limited construction-related activities along the pipeline route. The project has a targeted in-service date of late 2019. Due to delays in obtaining the required permits to commence construction and the conditions imposed upon the project by the permits, ACP's project manager estimates the project pipeline development costs have increased from a range of $5.0 billion to $5.5 billion to a range of $6.0 billion to $6.5 billion, excluding financing costs. Project construction activities, schedule and final costs are still subject to uncertainty due to potential additional permitting delays, construction productivity and other conditions and risks that could result in potential higher project costs and a potential delay in the targeted in-service date. See Note 3 to the Condensed Consolidated Financial Statements, "Regulatory Matters," for additional information.

Rapidly rising interest rates without timely or adequate updates to the regulated allowed return on equity or failure to achieve the anticipated benefits of the Piedmont merger, including cost savings and growth targets, could significantly impact the estimated fair value of reporting units in Gas Utilities and Infrastructure. In the event of a significant decline in the estimated fair value of the reporting units, goodwill impairment charges could be recorded. The carrying value of goodwill within Gas Utilities and Infrastructure was approximately $1,924 million at March 31, 2018.

96

PART I

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

Commercial Renewables

	Three Months Ended March 31,
(in millions)	2018			2017			Variance
Operating Revenues	$	101		$	128		$	(27	)
Operating Expenses
Operation, maintenance and other	55			78			(23		)
Depreciation and amortization	38			39			(1		)
Property and other taxes	7			9			(2		)
Total operating expenses	100			126			(26		)
Gains on Sales of Other Assets and Other, net	—			2			(2		)
Operating Income	1			4			(3		)
Other Income and Expenses	2			—			2
Interest Expense	22			19			3
Loss Before Income Taxes	(19		)	(15		)	(4		)
Income Tax Benefit	(39		)	(39		)	—
Less: Loss Attributable to Noncontrolling Interests	—			(1		)	1
Segment Income	$	20		$	25		$	(5	)
Renewable plant production, GWh	2,180			2,285			(105		)
Net proportional MW capacity in operation	2,943			2,943			—

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Commercial Renewables' results were impacted by lower wind resource in the current year. The following is a detailed discussion of the variance drivers by line item.

Operating Revenues. The decrease in revenues was primarily due to a reduction in the number of engineering, procurement and construction contracts at REC Solar, a California-based provider of solar installations owned by Duke Energy, and lower wind resource in the current year.

Operating Expenses. The decrease in operation, maintenance and other was primarily due to a reduction in the number of engineering, procurement and construction contracts at REC Solar in the current year.

Matters Impacting Future Commercial Renewables Results

Changes or variability in assumptions used in calculating the fair value of the Commercial Renewables reporting units for goodwill testing purposes, including but not limited to legislative actions related to tax credit extensions, long-term growth rates and discount rates could significantly impact the estimated fair value of the Commercial Renewables reporting units. In the event of a significant decline in the estimated fair value of the Commercial Renewables reporting units, goodwill or other asset impairment charges could be recorded. The carrying value of goodwill within Commercial Renewables was approximately $93 million at March 31, 2018.

Persistently low market pricing for wind resources, primarily in the Electric Reliability Council of Texas West market and the future expiration of tax incentives including investment tax credits and production tax credits could result in adverse impacts to the future results of Commercial Renewables.

Deterioration in credit quality resulting in bankruptcy of an offtaker of power from contracted wind or solar assets could result in adverse impacts to the future results of Commercial Renewables. On March 31, 2018, First Energy Solutions (FES), a subsidiary of First Energy and counterparty to two power purchase agreements with North Allegheny Windfarm, filed for Chapter 11 bankruptcy. Commercial Renewables cannot predict the impact of the bankruptcy on its financial results.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

97

PART I

Other

	Three Months Ended March 31,
(in millions)	2018			2017			Variance
Operating Revenues	$	35		$	33		$	2
Operating Expenses
Fuel used in electric generation and purchased power	14			15			(1		)
Operation, maintenance and other	3			8			(5		)
Depreciation and amortization	33			26			7
Property and other taxes	4			3			1
Total operating expenses	54			52			2
(Loss) Gains on Sales of Other Assets and Other, net	(101		)	5			(106		)
Operating Loss	(120		)	(14		)	(106		)
Other Income and Expenses	14			21			(7		)
Interest Expense	157			134			23
Loss Before Income Taxes	(263		)	(127		)	(136		)
Income Tax Expense (Benefit)	1			(52		)	53
Less: Income Attributable to Noncontrolling Interests	2			2			—
Net Loss	$	(266	)	$	(77	)	$	(189	)

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Other's higher net loss was driven by the loss on sale of the retired Beckjord generating station (Beckjord), higher interest expense and lower income tax benefit. The following is a detailed discussion of the variance drivers by line item.

(Loss) Gains on Sales of Other Assets and Other, net. The variance was driven by the loss on sale of Beckjord, a nonregulated facility retired during 2014, including the transfer of coal ash basins and other real property and indemnification from any and all potential future claims related to the property, whether arising under environmental laws or otherwise.

Interest Expense. The variance was primarily due to an increase in long-term debt as well as higher short-term interest rates.

Income Tax Expense (Benefit). The variance was primarily due to the valuation allowance against AMT credits partially offset by the lower statutory corporate tax rate associated with the Tax Act. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

98

PART I

Matters Impacting Future Other Results

Included in Other is Duke Energy Ohio's 9 percent ownership interest in the Ohio Valley Electric Corporation (OVEC), which owns 2,256 MW of coal-fired generation capacity. As a counterparty to an inter-company power agreement (ICPA), Duke Energy Ohio has a contractual arrangement to receive entitlements to capacity and energy from OVEC’s power plants through June 2040 commensurate with its power participation ratio, which is equivalent to Duke Energy Ohio's ownership interest. Costs, including fuel, operating expenses, fixed costs, debt amortization and interest expense, are allocated to counterparties to the ICPA, including Duke Energy Ohio, based on their power participation ratio. The value of the ICPA is subject to variability due to fluctuations in power prices and changes in OVEC’s costs of business. Deterioration in the credit quality or bankruptcy of one or more parties to the ICPA could increase the costs of OVEC. On March 31, 2018, FirstEnergy Solutions (FES), a subsidiary of FirstEnergy and counterparty to ICPA, filed for Chapter 11 bankruptcy. FES has a power participation ratio of 4.85 percent. Duke Energy cannot predict the impact of the bankruptcy on its OVEC interests. In addition, certain proposed environmental rulemaking costs could result in future increased cost allocations.

On March 2, 2017, Duke Energy Ohio filed an electric distribution base rate application with the PUCO to address recovery of electric distribution system capital investments and any increase in expenditures subsequent to previous rate cases. On April 13, 2018, Duke Energy Ohio filed a Stipulation with the PUCO to resolve issues in the electric distribution base rate case and other regulatory matters. If approved by PUCO, the Stipulation would allow for Duke Energy Ohio to recover gains and losses incurred on and after January 1, 2018 related to OVEC, through the Price Stabilization Rider and, as a result, Duke Energy Ohio may move its ownership interest to the Electric Utilities and Infrastructure segment. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters” for additional information.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

DUKE ENERGY CAROLINAS

Management’s Discussion and Analysis should be read in conjunction with the accompanying Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018, and 2017 and the Annual Report on Form 10-K/A for the year ended December 31, 2017.

Results of Operations

	Three Months Ended March 31,
(in millions)	2018		2017		Variance
Operating Revenues	$	1,763	$	1,716	$	47
Operating Expenses
Fuel used in electric generation and purchased power	473		428		45
Operation, maintenance and other	451		495		(44		)
Depreciation and amortization	272		254		18
Property and other taxes	72		68		4
Impairment charges	13		—		13
Total operating expenses	1,281		1,245		36
Operating Income	482		471		11
Other Income and Expenses, net	39		50		(11		)
Interest Expense	107		103		4
Income Before Income Taxes	414		418		(4		)
Income Tax Expense	91		148		(57		)
Net Income	$	323	$	270	$	53

The following table shows the percent changes in GWh sales and average number of customers. The percentages for retail customer classes represent billed sales only. Total sales includes billed and unbilled retail sales and wholesale sales to incorporated municipalities, public and private utilities and power marketers. Amounts are not weather-normalized.

Increase (Decrease) over prior year	2018
Residential sales	20.6	%
General service sales	6.4	%
Industrial sales	(1.5	)%
Wholesale power sales	19.7	%
Joint dispatch sales	(3.0	)%
Total sales	8.9	%
Average number of customers	1.5	%

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Operating Revenues.The variance was driven primarily by:

• an $84 million increase in retail sales, net of fuel revenues, due to a return to normal weather this year compared to the significantly warmer winter weather in the prior year;

• a $36 million increase in fuel related revenues primarily due to higher sales; and

99

PART I

• a $13 million increase in weather-normal retail sales volumes;

Partially offset by:

• a $61 million decrease in retail sales due to revenues subject to refund to customers associated with the lower statutory corporate tax rate under the Tax Act;

• a $12 million decrease in rider revenues primarily related to energy efficiency programs; and

• an $11 million decrease in wholesale power revenues, net of sharing and fuel, primarily due to customer refunds in the current year related to a FERC order on a complaint filed by the PMPA, partially offset by coal ash recovery.

Operating Expenses. The variance was driven primarily by:

• a $45 million increase in fuel used in electric generation and purchased power primarily due to higher sales;

• an $18 million increase in depreciation and amortization primarily due to additional plant in service and higher amortization of deferred coal ash costs; and

• a $13 million increase in impairment charges related to coal ash costs in South Carolina.

Partially offset by:

• a $44 million decrease in operation, maintenance and other expense primarily due to lower expenses at generating plants and lower storm restoration costs.

Other Income and Expenses. The variance was primarily due to lower AFUDC equity and a decrease in recognition of post in-service equity returns for projects that had been completed prior to being reflected in customer rates.

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 22.0 percent and 35.4 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Results

An order from regulatory authorities disallowing recovery of costs related to closure of ash impoundments could have an adverse impact on Duke Energy Carolinas' financial position, results of operations and cash flows. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

On May 18, 2016, the NCDEQ issued proposed risk classifications for all coal ash surface impoundments in North Carolina. All ash impoundments not previously designated as high priority by the Coal Ash Act were designated as intermediate risk. Certain impoundments classified as intermediate risk, however, may be reassessed in the future as low risk pursuant to legislation enacted on July 14, 2016. Duke Energy Carolinas' estimated AROs related to the closure of North Carolina ash impoundments are based upon the mandated closure method or a probability weighting of potential closure methods for the impoundments that may be reassessed to low risk. As the final risk ranking classifications in North Carolina are delineated, final closure plans and corrective action measures are developed and approved for each site, the closure work progresses, and the closure method scope and remedial action methods are determined, the complexity of work and the amount of coal combustion material could be different than originally estimated and, therefore, could materially impact Duke Energy Carolinas' financial position.

Duke Energy Carolinas is a party to multiple lawsuits and subject to fines and other penalties related to operations at certain North Carolina facilities with ash basins. The outcome of these lawsuits, fines and penalties could have an adverse impact on Duke Energy Carolinas’ financial position, results of operations and cash flows. See Note 4 to the Condensed Consolidated Financial Statements, “Commitments and Contingencies,” for additional information.

Duke Energy Carolinas filed a general rate case on August 25, 2017, to recover costs of complying with CCR regulations and the Coal Ash Act, as well as costs of capital investments in generation, transmission and distribution systems and any increase in expenditures subsequent to previous rate cases. Duke Energy Carolinas' earnings could be adversely impacted if the rate increase is delayed or denied by the NCUC. Hearings have concluded and a decision from the NCUC is expected by mid-2018. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

100

PART I

PROGRESS ENERGY

Management’s Discussion and Analysis should be read in conjunction with the accompanying Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018, and 2017 and the Annual Report on Form 10-K/A for the year ended December 31, 2017.

Results of Operations

	Three Months Ended March 31,
(in millions)	2018		2017		Variance
Operating Revenues	$	2,576	$	2,179	$	397
Operating Expenses
Fuel used in electric generation and purchased power	976		726		250
Operation, maintenance and other	623		560		63
Depreciation and amortization	384		313		71
Property and other taxes	123		117		6
Impairment charges	29		—		29
Total operating expenses	2,135		1,716		419
Gains on Sales of Other Assets and Other, net	6		8		(2		)
Operating Income	447		471		(24		)
Other Income and Expenses, net	35		40		(5		)
Interest Expense	209		206		3
Income Before Income Taxes	273		305		(32		)
Income Tax Expense	36		104		(68		)
Net Income	237		201		36
Less: Net Income Attributable to Noncontrolling Interests	2		2		—
Net Income Attributable to Parent	$	235	$	199	$	36

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Operating Revenues. The variance was driven primarily by:

• a $254 million increase in fuel related revenues due to higher sales and increases in fuel and capacity rates billed to customers;

• a $75 million increase in retail sales, net of fuel revenues, due to a return to normal weather this year compared to the significantly warmer winter weather in the prior year;

• a $47 million increase in wholesale power revenues, net of fuel, primarily due to coal ash recovery and higher peak demand in the current year at Duke Energy Progress;

• a $20 million increase in retail pricing due to the impacts of the Duke Energy Progress North Carolina and South Carolina rate cases, and Duke Energy Florida base rate adjustments for the Osprey acquisition and the completion of the Hines Energy Complex Chiller Uprate Project; and

• a $14 million increase in weather-normal retail sales volumes.

Partially offset by:

• a $33 million decrease due to revenues subject to refund to customers associated with the lower statutory corporate tax rate under the Tax Act at Duke Energy Progress.

Operating Expenses. The variance was driven primarily by:

• a $250 million increase in fuel used in electric generation and purchased power primarily due to higher sales, higher deferred fuel and capacity expenses, and increased purchased power partially offset by lower generation costs at Duke Energy Florida;

• a $71 million increase in depreciation and amortization primarily due to higher amortization of deferred coal ash costs and new depreciation rates per the North Carolina rate case at Duke Energy Progress, and accelerated depreciation of Crystal River Units 4 and 5 and additional plant in service at Duke Energy Florida;

• a $63 million increase in operation, maintenance and other primarily due to storm cost amortization at Duke Energy Florida and impacts associated with the North Carolina rate case at Duke Energy Progress; and

• a $29 million increase in impairment charges primarily due to the impacts associated with the North Carolina rate case at Duke Energy Progress.

101

PART I

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 13.2 percent and 34.1 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act and the amortization of federal and state excess deferred taxes. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Results

An order from regulatory authorities disallowing recovery of costs related to closure of ash impoundments could have an adverse impact on Progress Energy’s financial position, results of operations and cash flows. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

On May 18, 2016, the NCDEQ issued proposed risk classifications for all coal ash surface impoundments in North Carolina. All ash impoundments not previously designated as high priority by the Coal Ash Act were designated as intermediate risk. Certain impoundments classified as intermediate risk, however, may be reassessed in the future as low risk pursuant to legislation enacted on July 14, 2016. Progress Energy's estimated AROs related to the closure of North Carolina ash impoundments are based upon the mandated closure method or a probability weighting of potential closure methods for the impoundments that may be reassessed to low risk. As the final risk ranking classifications in North Carolina are delineated, final closure plans and corrective action measures are developed and approved for each site, the closure work progresses, and the closure method scope and remedial action methods are determined, the complexity of work and the amount of coal combustion material could be different than originally estimated and, therefore, could materially impact Progress Energy's financial position.

Duke Energy Progress is a party to multiple lawsuits and subject to fines and other penalties related to operations at certain North Carolina facilities with ash basins. The outcome of these lawsuits, fines and penalties could have an adverse impact on Progress Energy’s financial position, results of operations and cash flows. See Note 4 to the Condensed Consolidated Financial Statements, “Commitments and Contingencies,” for additional information.

Duke Energy Florida is constructing the 1,640-MW combined-cycle natural gas plant in Citrus County, Florida and expects it to be commercially available in 2018. Failure to complete the construction and achieve commercial operations by the end of 2018 could materially impact Duke Energy Florida’s financial position.

On February 6, 2018, the FPSC approved a stipulation that would apply tax savings resulting from the Tax Act toward storm costs effective January 2018 in lieu of implementing a storm surcharge. Storm costs are currently expected to be fully recovered by approximately mid-2021. The evidentiary hearing in this storm cost matter is scheduled for the week of October 15, 2018. An order disallowing recovery of these costs could have an adverse impact on Progress Energy's financial position. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

DUKE ENERGY PROGRESS

Management’s Discussion and Analysis should be read in conjunction with the accompanying Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018, and 2017 and the Annual Report on Form 10-K/A for the year ended December 31, 2017.

Results of Operations

	Three Months Ended March 31,
(in millions)	2018		2017		Variance
Operating Revenues	$	1,460	$	1,219	$	241
Operating Expenses
Fuel used in electric generation and purchased power	509		364		145
Operation, maintenance and other	381		362		19
Depreciation and amortization	235		181		54
Property and other taxes	35		40		(5		)
Impairment charges	32		—		32
Total operating expenses	1,192		947		245
Gains on Sales of Other Assets and Other, net	1		2		(1		)
Operating Income	269		274		(5		)
Other Income and Expenses, net	18		31		(13		)
Interest Expense	81		82		(1		)
Income Before Income Taxes	206		223		(17		)
Income Tax Expense	29		76		(47		)
Net Income	$	177	$	147	$	30

102

PART I

The following table shows the percent changes in GWh sales and average number of customers. The percentages for retail customer classes represent billed sales only. Total sales includes billed and unbilled retail sales, and wholesale sales to incorporated municipalities, public and private utilities and power marketers. Amounts are not weather-normalized.

Increase (Decrease) over prior period	2018
Residential sales	18.7	%
General service sales	5.2	%
Industrial sales	(2.1	)%
Wholesale power sales	15.9	%
Joint dispatch sales	(0.9	)%
Total sales	10.2	%
Average number of customers	1.5	%

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Operating Revenues. The variance was driven primarily by:

• a $150 million increase in fuel related revenues due to higher sales and increases in fuel rates billed to customers;

• a $50 million increase in retail sales, net of fuel revenues, due to a return to normal weather this year compared to the significantly warmer winter weather in the prior year;

• a $47 million increase in wholesale power revenues, net of fuel, primarily due to coal ash recovery and higher peak demand in the current year;

• a $12 million increase in retail pricing due to the impacts of the North Carolina and South Carolina rate cases; and

• a $9 million increase in weather-normal retail sales volumes.

Partially offset by:

• a $33 million decrease due to revenues subject to refund to customers associated with the lower statutory corporate tax rate under the Tax Act.

Operating Expenses. The variance was driven primarily by:

• a $145 million increase in fuel used in electric generation and purchased power primarily due to higher sales and higher deferred fuel expenses;

• a $54 million increase in depreciation and amortization primarily due to higher amortization of deferred coal ash costs and new depreciation rates per the North Carolina rate case;

• a $32 million increase in impairment charges due to the impacts associated with the North Carolina rate case; and

• a $19 million increase in operation, maintenance and other expense primarily due to impacts associated with the North Carolina rate case.

Other Income and Expenses. The variance was primarily driven by lower income from non-service components of employment benefit costs. For additional information on employee benefit costs, see Note 15 to the Condensed Consolidated Financial Statements, "Employee Benefit Plans."

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 14.1 percent and 34.1 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act and the amortization of state excess deferred taxes. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Results

An order from regulatory authorities disallowing recovery of costs related to closure of ash impoundments could have an adverse impact on Duke Energy Progress’ financial position, results of operations and cash flows. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

On May 18, 2016, the NCDEQ issued proposed risk classifications for all coal ash surface impoundments in North Carolina. All ash impoundments not previously designated as high priority by the Coal Ash Act were designated as intermediate risk. Certain impoundments classified as intermediate risk, however, may be reassessed in the future as low risk pursuant to legislation enacted on July 14, 2016. Duke Energy Progress' estimated AROs related to the closure of North Carolina ash impoundments are based upon the mandated closure method or a probability weighting of potential closure methods for the impoundments that may be reassessed to low risk. As the final risk ranking classifications in North Carolina are delineated, final closure plans and corrective action measures are developed and approved for each site, the closure work progresses, and the closure method scope and remedial action methods are determined, the complexity of work and the amount of coal combustion material could be different than originally estimated and, therefore, could materially impact Duke Energy Progress' financial position.

103

PART I

Duke Energy Progress is a party to multiple lawsuits and subject to fines and other penalties related to operations at certain North Carolina facilities with ash basins. The outcome of these lawsuits, fines and penalties could have an adverse impact on Duke Energy Progress’ financial position, results of operations and cash flows. See Note 4 to the Condensed Consolidated Financial Statements, “Commitments and Contingencies,” for additional information.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

DUKE ENERGY FLORIDA

Management’s Discussion and Analysis should be read in conjunction with the accompanying Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018, and 2017 and the Annual Report on Form 10-K/A for the year ended December 31, 2017.

Results of Operations

	Three Months Ended March 31,
(in millions)	2018		2017		Variance
Operating Revenues	$	1,115	$	959	$	156
Operating Expenses
Fuel used in electric generation and purchased power	467		362		105
Operation, maintenance and other	237		195		42
Depreciation and amortization	150		132		18
Property and other taxes	88		77		11
Impairment charges	—		1		(1		)
Total operating expenses	942		767		175
Operating Income	173		192		(19		)
Other Income and Expenses, net	21		20		1
Interest Expense	71		70		1
Income Before Income Taxes	123		142		(19		)
Income Tax Expense	20		52		(32		)
Net Income	$	103	$	90	$	13

The following table shows the percent changes in GWh sales and average number of customers. The percentages for retail customer classes represent billed sales only. Wholesale power sales include both billed and unbilled sales. Total sales includes billed and unbilled retail sales, and wholesale sales to incorporated municipalities, public and private utilities and power marketers. Amounts are not weather-normalized.

Increase (Decrease) over prior period	2018
Residential sales	18.4	%
General service sales	5.7	%
Industrial sales	0.4	%
Wholesale and other	84.5	%
Total sales	9.8	%
Average number of customers	1.6	%

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Operating Revenues. The variance was driven primarily by:

• a $104 million increase in fuel and capacity revenues primarily due to an increase in fuel and capacity rates billed to retail customers, as well as increased demand;

• a $25 million increase in retail sales, net of fuel revenues, due to a return to normal weather this year compared to the significantly warmer winter weather in the prior year;

• a $9 million increase in rider revenues primarily related to energy efficiency programs and franchise tax revenues; and

• an $8 million increase in retail pricing primarily due to the base rate adjustments for the Osprey acquisition and the completion of the Hines Energy Complex Chiller Uprate Project.

Operating Expenses. The variance was driven primarily by:

• a $105 million increase in fuel used in electric generation and purchased power primarily due to higher deferred fuel and capacity expenses, increased purchased power and increased demand partially offset by lower generation costs;

• a $42 million increase in operation, maintenance and other expense primarily due to storm cost amortization;

• an $18 million increase in depreciation and amortization primarily due to accelerated depreciation of Crystal River Units 4 and 5 and additional plant in service; and

104

PART I

• an $11 million increase in property and other taxes primarily due to higher revenue related taxes.

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 16.3 percent and 36.6 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act and the amortization of federal excess deferred taxes. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Results

Duke Energy Florida is constructing the 1,640-MW combined-cycle natural gas plant in Citrus County, Florida and expects it to be commercially available in 2018. Failure to complete the construction and achieve commercial operations by the end of 2018 could materially impact Duke Energy Florida’s financial position.

On February 6, 2018, the FPSC approved a stipulation that would apply tax savings resulting from the Tax Act toward storm costs effective January 2018 in lieu of implementing a storm surcharge. Storm costs are currently expected to be fully recovered by approximately mid-2021. The evidentiary hearing in this storm cost matter is scheduled for the week of October 15, 2018. An order disallowing recovery of these costs could have an adverse impact on Duke Florida's financial position. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

DUKE ENERGY OHIO

Management’s Discussion and Analysis should be read in conjunction with the accompanying Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018, and 2017 and the Annual Report on Form 10-K/A for the year ended December 31, 2017.

Results of Operations

	Three Months Ended March 31,
(in millions)	2018			2017		Variance
Operating Revenues
Regulated electric	$	336		$	337	$	(1	)
Regulated natural gas	174			170		4
Nonregulated electric and other	14			11		3
Total operating revenues	524			518		6
Operating Expenses
Fuel used in electric generation and purchased power – regulated	92			97		(5		)
Fuel used in electric generation and purchased power – nonregulated	15			15		—
Cost of natural gas	54			54		—
Operation, maintenance and other	131			131		—
Depreciation and amortization	70			67		3
Property and other taxes	77			72		5
Total operating expenses	439			436		3
Loss on Sales of Other Assets and Other, net	(106		)	—		(106		)
Operating (Loss) Income	(21		)	82		(103		)
Other Income and Expenses, net	6			5		1
Interest Expense	22			22		—
(Loss) Income Before Income Taxes	(37		)	65		(102		)
Income Tax (Benefit) Expense	(12		)	23		(35		)
Net (Loss) Income	$	(25	)	$	42	$	(67	)

The following table shows the percent changes in GWh sales and average number of customers. The percentages for retail customer classes represent billed sales only. Total sales includes billed and unbilled retail sales and wholesale sales to incorporated municipalities, public and private utilities and power marketers. Amounts are not weather-normalized.

	Electric		Natural Gas
Increase (Decrease) over prior year	2018		2018
Residential sales	13.8	%	26.9	%
General service sales	2.7	%	23.5	%
Industrial sales	(3.7	)%	14.0	%
Wholesale electric power sales	(64.4	)%	n/a
Other natural gas sales	n/a		2.8	%
Total sales	0.2	%	20.4	%
Average number of customers	0.9	%	0.9	%

105

PART I

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Operating Revenues. The variance was driven primarily by:

• a $14 million increase in electric and natural gas retail sales, net of fuel revenues, due to a return to normal weather this year compared to the significantly warmer winter weather in the prior year;

• an $11 million increase in financial transmission rights revenues;

• a $5 million increase in rider revenues primarily due to increased rates; and

• a $3 million increase in other revenues related to OVEC.

Partially offset by:

• a $16 million decrease in regulated revenues due to revenues subject to refund to customers associated with the lower statutory corporate tax rate under the Tax Act; and

•a $10 million decrease in fuel related revenues primarily due to lower fuel prices.

Operating Expenses. The variance was driven primarily by:

•a $5 million increase in property and other taxes primarily due to higher property taxes; and

• a $3 million increase in depreciation and amortization primarily due to additional plant in service.

Partially offset by:

• a $5 million decrease in fuel used in electric generation and purchased power due to lower fuel costs.

Loss on Sales of Other Assets and Other, net. The decrease was driven by the loss on the sale of Beckjord, a nonregulated facility retired during 2014, including the transfer of coal ash basins and other real property and indemnification from any and all potential future claims related to the property, whether arising under environmental laws or otherwise.

Income Tax (Benefit) Expense. The variance was primarily due to a decrease in pretax income and the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 32.4 percent and 35.4 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act, partially offset by tax levelization related to federal excess deferred taxes on a pretax loss in the current year. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Results

An order from regulatory authorities disallowing recovery of costs related to closure of ash basins could have an adverse impact on Duke Energy Ohio's financial position, results of operations and cash flows. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

Duke Energy Ohio has a 9 percent ownership interest in OVEC, which owns 2,256 MW of coal-fired generation capacity. As a counterparty to an ICPA, Duke Energy Ohio has a contractual arrangement to receive entitlements to capacity and energy from OVEC’s power plants through June 2040 commensurate with its power participation ratio, which is equivalent to Duke Energy Ohio’s ownership interest. Costs, including fuel, operating expenses, fixed costs, debt amortization and interest expense, are allocated to counterparties to the ICPA, including Duke Energy Ohio, based on their power participation ratio. The value of the ICPA is subject to variability due to fluctuations in power prices and changes in OVEC’s costs of business. Deterioration in the credit quality or bankruptcy of one or more parties to the ICPA could increase the costs of OVEC. On March 31, 2018, FES, a subsidiary of FirstEnergy and counterparty to ICPA, filed for Chapter 11 bankruptcy. FES has a power participation ratio of 4.85 percent. Duke Energy cannot predict the impact of the bankruptcy on its OVEC interests. In addition, certain proposed environmental rulemaking costs could result in future increased cost allocations.

On March 2, 2017, Duke Energy Ohio filed an electric distribution base rate application with the PUCO to address recovery of electric distribution system capital investments and any increase in expenditures subsequent to previous rate cases. On April 13, 2018, Duke Energy Ohio filed a Stipulation with the PUCO to resolve issues in the electric distribution base rate case and other regulatory matters. If approved by PUCO, the Stipulation would allow for Duke Energy Ohio to recover gains and losses incurred on and after January 1, 2018 related to OVEC, through the Price Stabilization Rider. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

DUKE ENERGY INDIANA

Management’s Discussion and Analysis should be read in conjunction with the accompanying Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018, and 2017 and the Annual Report on Form 10-K/A for the year ended December 31, 2017.

106

PART I

Results of Operations

	Three Months Ended March 31,
(in millions)	2018		2017		Variance
Operating Revenues	$	731	$	758	$	(27	)
Operating Expenses
Fuel used in electric generation and purchased power	232		251		(19		)
Operation, maintenance and other	181		176		5
Depreciation and amortization	130		125		5
Property and other taxes	20		22		(2		)
Total operating expenses	563		574		(11		)
Operating Income	168		184		(16		)
Other Income and Expenses, net	7		10		(3		)
Interest Expense	40		44		(4		)
Income Before Income Taxes	135		150		(15		)
Income Tax Expense	35		59		(24		)
Net Income	$	100	$	91	$	9

The following table shows the percent changes in GWh sales and average number of customers. The percentages for retail customer classes represent billed sales only. Total sales includes billed and unbilled retail sales and wholesale sales to incorporated municipalities, public and private utilities and power marketers. Amounts are not weather-normalized.

Increase (Decrease) over prior year	2018
Residential sales	15.4	%
General service sales	2.1	%
Industrial sales	(0.8	)%
Wholesale power sales	(0.6	)%
Total sales	3.4	%
Average number of customers	0.8	%

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Operating Revenues.The variance was driven primarily by:

• a $27 million decrease due to revenues subject to refund to customers associated with the lower statutory corporate tax rate under the Tax Act; and

• a $10 million decrease in fuel related revenues primarily due to lower purchased power costs passed through to customers and lower financial transmission rights revenues.

Partially offset by:

• a $12 million increase in rate rider revenues primarily related to the Edwardsport IGCC plant and the Transmission, Distribution and Storage System Improvement Charge.

Operating Expenses.The variance was driven primarily by:

• a $19 million decrease in fuel used in electric generation and purchased power primarily due to the net benefit to expense of reduced purchased power and increased internal generation and lower fuel prices.

Partially offset by:

• a $5 million increase in operation, maintenance and other expense primarily due to higher transmission costs; and

• a $5 million increase in depreciation and amortization primarily due to additional plant in service and higher deferred coal ash costs; partially offset by the completion of the amortization of a regulated asset for costs associated with the termination of a gasification services agreement in 2000.

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 25.9 percent and 39.3 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

107

PART I

Matters Impacting Future Results

On April 17, 2015, the EPA published in the Federal Register a rule to regulate the disposal of CCR from electric utilities as solid waste. Duke Energy Indiana has interpreted the rule to identify the coal ash basin sites impacted and has assessed the amounts of coal ash subject to the rule and a method of compliance. Duke Energy Indiana's interpretation of the requirements of the CCR rule is subject to potential legal challenges and further regulatory approvals, which could result in additional ash basin closure requirements, higher costs of compliance and greater AROs. Additionally, Duke Energy Indiana has retired facilities that are not subject to the CCR rule. Duke Energy Indiana may incur costs at these facilities to comply with environmental regulations or to mitigate risks associated with on-site storage of coal ash. An order from regulatory authorities disallowing recovery of costs related to closure of ash basins could have an adverse impact on Duke Energy Indiana's financial position, results of operations and cash flows. See Note 3 to the Condensed Consolidated Financial Statements, “Regulatory Matters,” for additional information.

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

PIEDMONT

Management’s Discussion and Analysis should be read in conjunction with the Condensed Consolidated Financial Statements and Notes for the three months ended March 31, 2018 and 2017 and the Annual Report on Form 10-K/A for the year ended December 31, 2017.

Results of Operations

	Three Months Ended March 31,
(in millions)	2018		2017		Variance
Operating Revenues	$	553	$	500	$	53
Operating Expenses
Cost of natural gas	259		205		54
Operation, maintenance and other	82		77		5
Depreciation and amortization	39		35		4
Property and other taxes	12		13		(1		)
Total operating expenses	392		330		62
Operating Income	161		170		(9		)
Other Income and Expenses
Equity in earnings of unconsolidated affiliates	2		3		(1		)
Other income and expenses, net	3		—		3
Total other income and expenses	5		3		2
Interest Expense	21		20		1
Income Before Income Taxes	145		153		(8		)
Income Tax Expense	35		58		(23		)
Net Income	$	110	$	95	$	15

The following table shows the percent changes in dekatherms delivered and average number of customers. The percentages for all throughput deliveries represent billed and unbilled sales. Amounts are not weather-normalized.

Increase (Decrease) over prior year	2018
Residential deliveries	39.4	%
Commercial deliveries	33.9	%
Industrial deliveries	4.5	%
Power generation deliveries	8.9	%
For resale	28.0	%
Total throughput deliveries	16.2	%
Secondary market volumes	(13.7	)%
Average number of customers	1.8	%

Due to the margin decoupling mechanism in North Carolina and weather normalization adjustment (WNA) mechanisms in South Carolina and Tennessee, changes in throughput deliveries do not have a material impact on Piedmont's revenues or earnings. The margin decoupling mechanism adjusts for variations in residential and commercial use per customer, including those due to weather and conservation. The WNA mechanisms mostly offset the impact of weather on bills rendered, but do not ensure full recovery of approved margin during periods when winter weather is significantly warmer or colder than normal.

Three Months Ended March 31, 2018, as Compared to March 31, 2017

Operating Revenues.The variance was driven primarily by:

• a $54 million increase due to higher natural gas costs passed through to customers due to higher volumes sold and higher natural gas prices; and

108

PART I

• a $22 million increase primarily due to residential and commercial customer revenue, net of natural gas costs passed through to customers, due to customer growth and IMR rate adjustments.

Partially offset by:

• a $23 million decrease due to revenues subject to refund to customers associated with the lower statutory corporate tax rate under the Tax Act.

Operating Expenses.The variance was driven by:

• a $54 million increase in cost of natural gas due to higher volumes sold and higher natural gas prices;

• a $5 million increase in operation, maintenance and other primarily due to increased corporate, customer operations and costs to achieve merger expenses; and

• a $4 million increase in depreciation and amortization due to additional plant in service.

Income Tax Expense. The variance was primarily due to the lower statutory corporate tax rate associated with the Tax Act. The ETRs for the three months ended March 31, 2018, and 2017 were 24.1 percent and 37.9 percent, respectively. The decrease in the ETR was primarily due to the lower statutory corporate tax rate associated with the Tax Act. For additional information, see Note 16 to the Condensed Consolidated Financial Statements, "Income Taxes."

Matters Impacting Future Results

See "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations," in the Duke Energy Registrants' Annual Reports on Form 10-K/A for the year ended December 31, 2017, for discussion of risks associated with the Tax Act.

LIQUIDITY AND CAPITAL RESOURCES

Sources and Uses of Cash

Duke Energy relies primarily upon cash flows from operations, debt issuances and its existing cash and cash equivalents to fund its liquidity and capital requirements. Duke Energy’s capital requirements arise primarily from capital and investment expenditures, repaying long-term debt and paying dividends to shareholders. See Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017, for a summary and detailed discussion of projected primary sources and uses of cash for 2018 to 2020.

The Subsidiary Registrants generally maintain minimal cash balances and use short-term borrowings to meet their working capital needs and other cash requirements. The Subsidiary Registrants, excluding Progress Energy (Parent), support their short-term borrowing needs through participation with Duke Energy and certain of its other subsidiaries in a money pool arrangement. The companies with short-term funds may provide short-term loans to affiliates participating under this arrangement.

Duke Energy and the Subsidiary Registrants, excluding Progress Energy (Parent), may also use short-term debt, including commercial paper and the money pool, as a bridge to long-term debt financings. The levels of borrowing may vary significantly over the course of the year due to the timing of long-term debt financings and the impact of fluctuations in cash flows from operations. From time to time, Duke Energy’s current liabilities may exceed current assets resulting from the use of short-term debt as a funding source to meet scheduled maturities of long-term debt, as well as cash needs, which can fluctuate due to the seasonality of its business.

CREDIT FACILITIES AND REGISTRATION STATEMENTS

Refer to Note 5 to the Condensed Consolidated Financial Statements, "Debt and Credit Facilities," for further information regarding Duke Energy's available credit facilities, including the Master Credit Facility.

Shelf Registration

In September 2016, Duke Energy filed a registration statement (Form S-3) with the U.S. Securities and Exchange Commission. Under this Form S-3, which is uncapped, the Duke Energy Registrants, excluding Progress Energy (Parent), may issue debt and other securities in the future at amounts, prices and with terms to be determined at the time of future offerings. The registration statement also allows for the issuance of common stock by Duke Energy.

In January 2017, Duke Energy amended its Form S-3 to add Piedmont as a registrant and included in the amendment a prospectus for Piedmont under which it may issue debt securities in the same manner as other Duke Energy Registrants.

DEBT MATURITIES

Refer to Note 5 to the Condensed Consolidated Financial Statements, "Debt and Credit Facilities," for further information regarding significant components of Current Maturities of Long-Term Debt on the Condensed Consolidated Balance Sheets.

CASH FLOWS FROM OPERATING ACTIVITIES

Cash flows from operations of Electric Utilities and Infrastructure and Gas Utilities and Infrastructure are primarily driven by sales of electricity and natural gas, respectively, and costs of operations. These cash flows from operations are relatively stable and comprise a substantial portion of Duke Energy’s operating cash flows. Weather conditions, working capital and commodity price fluctuations, and unanticipated expenses including unplanned plant outages, storms, legal costs and related settlements, and regulatory orders can affect the timing and level of cash flows from operations.

109

PART I

Duke Energy believes it has sufficient liquidity resources through the commercial paper markets, and ultimately the Master Credit and Revolving Facilities, to support these operations. Cash flows from operations are subject to a number of other factors, including but not limited to regulatory constraints, economic trends and market volatility (see “Item 1A. Risk Factors,” in the Duke Energy Registrants’ Annual Reports on Form 10-K/A for additional information).

Restrictive Debt Covenants

The Duke Energy Registrants’ debt and credit agreements contain various financial and other covenants. The Master Credit Facility contains a covenant requiring the debt-to-total capitalization ratio not to exceed 65 percent for all borrowers except Piedmont, and 70 percent for Piedmont. Failure to meet those covenants beyond applicable grace periods could result in accelerated due dates and/or termination of the agreements or sublimits thereto. As of March 31, 2018, each of the Duke Energy Registrants was in compliance with all covenants related to their debt agreements. In addition, some credit agreements may allow for acceleration of payments or termination of the agreements due to nonpayment or acceleration of other significant indebtedness of the borrower or some of its subsidiaries. None of the debt or credit agreements contain material adverse change clauses.

Credit Ratings

Credit ratings are intended to provide credit lenders a framework for comparing the credit quality of securities and are not a recommendation to buy, sell or hold. The Duke Energy Registrants’ credit ratings are dependent on the rating agencies’ assessments of their ability to meet their debt principal and interest obligations when they come due. If, as a result of market conditions or other factors, the Duke Energy Registrants are unable to maintain current balance sheet strength or if earnings and cash flow outlook materially deteriorate, credit ratings could be negatively impacted.

Moody’s Investors Service, Inc. (Moody’s), Standard & Poor’s Rating Services and Fitch Ratings, Inc. provide credit ratings for various Duke Energy Registrants.

In January 2018, Moody's revised the ratings outlook for Duke Energy Corporation and Piedmont from stable to negative, principally due to risk of deterioration in credit metrics resulting from the Tax Act.

Cash Flow Information

The following table summarizes Duke Energy’s cash flows.

	Three Months Ended
	March 31,
(in millions)	2018			2017
Cash flows provided by (used in):
Operating activities	$	1,391		$	1,246
Investing activities	(2,264		)	(2,361		)
Financing activities	947			1,596
Net increase in cash, cash equivalents and restricted cash	74			481
Cash, cash equivalents and restricted cash at beginning of period	505			541
Cash, cash equivalents and restricted cash at end of period	$	579		$	1,022

OPERATING CASH FLOWS

The following table summarizes key components of Duke Energy’s operating cash flows.

	Three Months Ended
	March 31,
(in millions)	2018			2017
Net income	$	622		$	717
Non-cash adjustments to net income	1,610			1,237
Contributions to qualified pension plans	(141		)	—
Payments for asset retirement obligations	(122		)	(134		)
Payment for disposal of other assets	(105		)	—
Working capital	(473		)	(574		)
Net cash provided by operating activities	$	1,391		$	1,246

The variance was primarily due to:

• a $278 million increase in net income after adjustment for non-cash items primarily due to a return to normal weather this year compared to the significantly warmer winter weather in the prior year, increased pricing and increased rider revenue; and

• a $101 million decrease in cash outflows from working capital due primarily to timing of payment of accruals;

110

PART I

Partially offset by:

• a $141 million increase in contributions to qualified pension plans; and

• a $105 million payment for disposal of Beckjord.

INVESTING CASH FLOWS

The following table summarizes key components of Duke Energy’s investing cash flows.

	Three Months Ended
	March 31,
(in millions)	2018			2017
Capital, investment and acquisition expenditures	$	(2,161	)	$	(2,335	)
Other investing items	(103		)	(26		)
Net cash used in investing activities	$	(2,264	)	$	(2,361	)

The variance was primarily due to:

• a $101 million decrease in contributions to equity investments due to projects self funding as they near completion and projects placed in service in 2017; and

• a $73 million decrease due to lower overall investments in regulated generation and natural gas, partially offset by increased investments in commercial renewables;

Partially offset by:

• a $47 million increase in cash used for other investing items related to debt and equity securities; and

• a $42 million increase in cash used for cost of removal, net of salvage value primarily due to increased spending for replacement projects in the Electric Utilities and Infrastructure segment.

FINANCING CASH FLOWS

The following table summarizes key components of Duke Energy’s financing cash flows.

	Three Months Ended
	March 31,
(in millions)	2018			2017
Issuances of long-term debt, net	$	753		$	1,155
Issuances of common stock	21			—
Notes payable and commercial paper	791			1,063
Dividends paid	(599		)	(600		)
Other financing items	(19		)	(22		)
Net cash provided by financing activities	$	947		$	1,596

The variance was primarily due to:

• a $402 million decrease in proceeds from net issuances of long-term debt mainly due to the timing of issuances and redemptions of long-term debt; and

• a $272 million decrease in net proceeds from issuances of notes payable and commercial paper primarily due to lower capital spending in the current period and an increase in commercial paper in prior year to fund repayment of debt.

Summary of Significant Debt Issuances

Refer to Note 5 to the Condensed Consolidated Financial Statements, "Debt and Credit Facilities," for further information regarding significant debt issuances.

OTHER MATTERS

Environmental Regulations

The Duke Energy Registrants are subject to federal, state and local regulations regarding air and water quality, hazardous and solid waste disposal and other environmental matters. These regulations can be changed from time to time and result in new obligations of the Duke Energy Registrants.

The following sections outline various proposed and recently enacted regulations that may impact the Duke Energy Registrants. Refer to Note 3 to the Condensed Consolidated Financial Statements, "Regulatory Matters," for further information regarding potential plant retirements and regulatory filings related to the Duke Energy Registrants.

111

PART I

Coal Combustion Residuals

In April 2015, the EPA published a rule to regulate the disposal of CCR from electric utilities as solid waste. The federal regulation classifies CCR as nonhazardous waste and allows for beneficial use of CCR with some restrictions. The regulation applies to all new and existing landfills, new and existing surface impoundments receiving CCR and existing surface impoundments that are no longer receiving CCR but contain liquid located at stations currently generating electricity (regardless of fuel source). The rule establishes requirements regarding landfill design, structural integrity design and assessment criteria for surface impoundments, groundwater monitoring, protection and remedial procedures and other operational and reporting procedures to ensure the safe disposal and management of CCR. Various industry and environmental parties have appealed the EPA's CCR rule in the U.S. Court of Appeals for the District of Columbia (D.C. Circuit Court). On April 18, 2016, the EPA filed a motion with the federal court to settle five issues raised in litigation. On June 14, 2016, the court approved the motion with respect to all of those issues. Duke Energy does not expect a material impact from the settlement or that it will result in additional ARO adjustments. On September 13, 2017, EPA responded to a petition by the Utility Solid Waste Activities Group that the agency would reconsider certain provisions of the final rule, and asked the D.C. Circuit Court to suspend the litigation. The D.C. Circuit Court denied EPA’s petition to suspend the litigation and oral argument was held on November 20, 2017. The court has not issued an order in the matter. Duke Energy cannot predict the outcome of the litigation.

On March 15, 2018, EPA published proposed amendments to the federal CCR rule, including revisions that were required as part of a CCR litigation settlement, as well as changes that the agency considers warranted due to the passage of the Water Infrastructure Improvements for the Nation Act, which provides statutory authority for state and federal permit programs. The proposed amendments do not repeal the CCR rule, and the rule’s major requirements for groundwater monitoring, location restrictions, operating criteria, and design standards remain in place. Duke Energy does not expect any significant changes to our coal ash basin closure plans or compliance requirements under the CCR rule.

In addition to the requirements of the federal CCR regulation, CCR landfills and surface impoundments will continue to be independently regulated by most states. Cost recovery for future expenditures will be pursued through the normal ratemaking process with federal and state utility commissions and via wholesale contracts, which permit recovery of necessary and prudently incurred costs associated with Duke Energy’s regulated operations. For more information, see Note 9, “Asset Retirement Obligations,” in Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

Coal Ash Management Act of 2014

Asset retirement obligations recorded on the Duke Energy Carolinas and Duke Energy Progress Condensed Consolidated Balance Sheets at March 31, 2018, and December 31, 2017, include the legal obligation for closure of coal ash basins and the disposal of related ash as a result of the Coal Ash Act, the EPA CCR rule and other agreements. The Coal Ash Act requires Duke Energy to undertake dam improvement projects and to provide access to a permanent alternative drinking water source to certain residents within a half-mile of coal ash basin compliance boundaries and to certain other potentially impacted residents. The legislation requires excavation of the Sutton, Riverbend and Dan River basins by August 1, 2019, and Asheville basins by August 1, 2022. Excavation at these sites may include a combination of transfer of coal ash to an engineered landfill or conversion for beneficial use. Basins at the H.F. Lee, Cape Fear and Weatherspoon sites are required to be closed through excavation no later than August 1, 2028. Excavation at these sites can include conversion of the basin to a lined industrial landfill, transfer of ash to an engineered landfill or conversion for beneficial use. The remaining basins are required to be closed no later than December 31, 2024, through conversion to a lined industrial landfill, transfer to an engineered landfill or conversion for beneficial use, unless certain dam improvement projects and alternative drinking water source projects are completed by October 15, 2018. Upon satisfactory completion of these projects, the closure deadline would be extended to December 31, 2029, and could include closure through the combination of a cap system and a groundwater monitoring system.

Additionally, the Coal Ash Act requires the installation and operation of three large-scale coal ash beneficiation projects to produce reprocessed ash for use in the concrete industry. Duke Energy selected the Buck, H.F. Lee and Cape Fear plants for these projects. Closure at these sites is required to be completed no later than December 31, 2029.

The Coal Ash Act includes a variance procedure for compliance deadlines and other issues surrounding the management of CCR and CCR surface impoundments and prohibits cost recovery in customer rates for unlawful discharge of ash impoundment waters occurring after January 1, 2014. The Coal Ash Act leaves the decision on cost recovery determinations related to closure of ash impoundments to the normal ratemaking processes before utility regulatory commissions. Consistent with the requirements of the Coal Ash Act, Duke Energy has submitted comprehensive site assessments and groundwater corrective plans to NCDEQ and will submit to NCDEQ site-specific coal ash impoundment closure plans in advance of closure. These plans and all associated permits must be approved by NCDEQ before closure work can begin.

For more information, see Note 9, “Asset Retirement Obligations,” in Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

Clean Water Act 316(b)

The EPA published the final 316(b) cooling water intake structure rule on August 15, 2014, with an effective date of October 14, 2014. The rule applies to 26 of the electric generating facilities the Duke Energy Registrants own and operate. The rule allows for several options to demonstrate compliance and provides flexibility to the state environmental permitting agencies to make determinations on controls, if any, that will be required for cooling water intake structures. Any required intake structure modifications and/or retrofits are expected to be installed in the 2019 to 2023 time frame. Petitions challenging the rule have been filed by several groups. Oral argument was held on September 14, 2017. It is unknown when the courts will rule on the petitions. The Duke Energy Registrants cannot predict the outcome of these matters.

112

PART I

Steam Electric Effluent Limitations Guidelines

On January 4, 2016, the final Steam Electric Effluent Limitations Guidelines (ELG) rule became effective. The rule establishes new requirements for wastewater streams associated with steam electric power generation and includes more stringent controls for any new coal plants that may be built in the future. As originally written, affected facilities were required to comply between 2018 and 2023, depending on the timing of Clean Water Act (CWA) discharge permits. Most of the steam electric generating facilities the Duke Energy Registrants own are affected sources. The Duke Energy Registrants are well-positioned to meet the majority of the requirements of the rule due to current efforts to convert to dry ash handling. Petitions challenging the rule have been filed by several groups. On March 16, 2015, Duke Energy Indiana filed its own legal challenge to the rule with the Seventh Circuit Court of Appeals specific to the ELG rule focused on the limits imposed on IGCC facilities (gasification wastewater). All challenges to the rule were consolidated in the Fifth Circuit Court of Appeals. On August 22, 2017, the Fifth Circuit Court of Appeals granted EPA’s Motion to Govern Further Proceedings, thereby severing and suspending the claims related to flue gas desulfurization wastewater, bottom ash transport water and gasification wastewater. Claims regarding gasification wastewater were stayed, pending the issuance of the variance to Duke Energy Indiana. Duke Energy Indiana’s federal court challenge to EPA’s Effluent Limitations Guidelines and Standards for the Steam Electric Power Generating Point Source Category remains in abeyance. After a long delay, EPA issued a variance for discharges at Edwardsport of wastewater associated with the gasification process. The variance will be incorporated by the state agency into a new wastewater discharge permit. Once the permit has issued and the time limit for a third-party challenge expires, Duke Energy Indiana will voluntarily dismiss the federal court challenge. The litigation will continue as to claims related to other waste streams.

Separate from the litigation, EPA finalized a rule on September 18, 2017, postponing the earliest applicability date for bottom ash transport water and flue gas desulfurization wastewater from 2018 to 2020 and retaining the end applicability date of 2023. Also, as part of the rule, EPA reiterated its intent to conduct a new rulemaking to review the effluent limitation guidelines for bottom ash transport water and flue gas desulfurization wastewater. EPA projects that a new rule on these two issues will be finalized by late 2020.

The Duke Energy Registrants cannot predict the outcome of these matters.

Estimated Cost and Impacts of Rulemakings

Duke Energy will incur capital expenditures to comply with the environmental regulations and rules discussed above. The following table provides five-year estimated costs, excluding AFUDC, of new control equipment that may need to be installed on existing power plants primarily to comply with the Coal Ash Act requirements for conversion to dry disposal of bottom ash and fly ash, CWA 316(b) and ELGs through December 31, 2022. The table excludes ash basin closure costs recorded in Asset retirement obligations on the Condensed Consolidated Balance Sheets. For more information related to AROs, see Note 9, “Asset Retirement Obligations” in Duke Energy’s Annual Report on Form 10‑K/A for the year ended December 31, 2017.

(in millions)	Estimated Cost
Duke Energy	$	850
Duke Energy Carolinas	370
Progress Energy	360
Duke Energy Progress	230
Duke Energy Florida	130
Duke Energy Ohio	70
Duke Energy Indiana	50

The Duke Energy Registrants also expect to incur increased fuel, purchased power, operation and maintenance and other expenses, in addition to costs for replacement generation for potential coal-fired power plant retirements, as a result of these regulations. Actual compliance costs incurred may be materially different from these estimates due to reasons such as the timing and requirements of EPA regulations and the resolution of legal challenges to the rules. The Duke Energy Registrants intend to seek rate recovery of necessary and prudently incurred costs associated with regulated operations to comply with these regulations.

Cross-State Air Pollution Rule

On September 7, 2016, EPA finalized a revision to the Cross-State Air Pollution Rule (CSAPR); the revised rule is known as the CSAPR Update Rule. The CSAPR Update Rule reduces the CSAPR Phase 2 state ozone season NOX emission budgets for 22 eastern states, including Ohio, Kentucky and Indiana. In the final CSAPR Update Rule, the EPA removed Florida, South Carolina and North Carolina from the ozone season NOx program. Beginning in 2017, Duke Energy Registrants in these states will not be subject to any CSAPR ozone season NOx emission limitations. For the states that remain in the program, the reduced state ozone season NOx emission budgets took effect on May 1, 2017. In Kentucky and Indiana, where Duke Energy Registrants own and operate coal-fired electric generating units (EGUs) subject to the final rule requirements, near-term responses include changing unit dispatch to run certain generating units less frequently and/or purchasing NOx allowances from the trading market. Longer term, upgrading the performance of existing NOx controls is an option. The Indiana Utility Group and the Indiana Energy Association jointly filed a petition for reconsideration asking that the EPA correct errors it made in calculating the Indiana budget and increase the budget accordingly. EPA has yet to act on the petition. Numerous parties have filed petitions with the D.C. Circuit Court challenging various aspects of the CSAPR Update Rule. Final briefs in the case were due April 9, 2018. The date for oral argument has not been established. The Duke Energy Registrants cannot predict the outcome of these matters.

113

PART I

Carbon Pollution Standards for New, Modified and Reconstructed Power Plants

On October 23, 2015, the EPA published a final rule in the Federal Register establishing carbon dioxide (CO2) emissions limits for new, modified and reconstructed power plants. The requirements for new plants apply to plants that commenced construction after January 8, 2014. The EPA set an emissions standard for coal units of 1,400 pounds of CO₂ per gross MWh, which would require the application of partial carbon capture and storage (CCS) technology for a coal unit to be able to meet the limit. Utility-scale CCS is not currently a demonstrated and commercially available technology for coal-fired EGUs, and therefore the final standard effectively prevents the development of new coal-fired generation. The EPA set a final standard of 1,000 pounds of CO2 per gross MWh for new natural gas combined-cycle units.

On March 28, 2017, President Trump signed an executive order directing EPA to review the rule and determine whether to suspend, revise or rescind it. On the same day, the Department of Justice (DOJ) filed a motion with the D.C. Circuit Court requesting that the court stay the litigation of the rule while it is reviewed by EPA. Subsequent to the DOJ motion, the D.C. Circuit Court canceled oral argument in the case. On August 10, 2017, the court ordered that the litigation be suspended indefinitely. The rule remains in effect pending the outcome of litigation and EPA’s review. EPA has not announced a schedule for completing its review. The Duke Energy Registrants cannot predict the outcome of these matters but do not expect the impacts of the current final standards will be material to Duke Energy's financial position, results of operations or cash flows.

Clean Power Plan

On October 23, 2015, the EPA published in the Federal Register the final Clean Power Plan (CPP) rule to regulate CO₂ emissions from existing fossil fuel-fired EGUs. The CPP established CO₂ emission rates and mass cap goals that apply to existing fossil fuel-fired EGUs. Petitions challenging the rule have been filed by numerous groups and on February 9, 2016, the Supreme Court issued a stay of the final CPP rule, halting implementation of the CPP until legal challenges are resolved. States in which the Duke Energy Registrants operate have suspended work on the CPP in response to the stay. Oral arguments before 10 of the 11 judges on D.C. Circuit Court were heard on September 27, 2016. The court has not issued its opinion in the case.

On March 28, 2017, President Trump signed an executive order directing EPA to review the CPP and determine whether to suspend, revise or rescind the rule. On the same day, the DOJ filed a motion with the D.C. Circuit Court requesting that the court stay the litigation of the rule while it is reviewed by EPA. On April 28, 2017, the court issued an order to suspend the litigation for 60 days. On August 8, 2017, the court, on its own motion, extended the suspension of the litigation for an additional 60 days. On October 16, 2017, EPA issued a Notice of Proposed Rulemaking (NPR) to repeal the CPP based on a change to EPA’s legal interpretation of the section of the Clean Air Act on which the CPP was based. In the proposal, EPA indicates that it has not determined whether it will issue a rule to replace the CPP, and if it will do so, when and what form that rule will take. The comment period on EPA's NPR ended April 26, 2018. On December 28, 2017, EPA issued an Advance Notice of Proposed Rulemaking (ANPRM) in which it seeks public comment on various aspects of a potential CPP replacement rule. The comment period on the ANPRM ended February 26, 2018. If EPA decides to move forward with a CPP replacement rule, it will need to issue a formal proposal for public comment. Litigation of the CPP remains on hold in the D.C. Circuit Court and the February 2016 U.S. Supreme Court stay of the CPP remains in effect. The Duke Energy Registrants cannot predict the outcome of these matters.

Section 126 Petitions

On November 16, 2016, the State of Maryland filed a petition with EPA under Section 126 of the Clean Air Act alleging that 19 power plants, including two that Duke Energy Registrants own and operate, contribute to violations of EPA’s National Ambient Air Quality Standards (NAAQS) for ozone in the State of Maryland. On March 12, 2018, the State of New York filed a petition with EPA, also under Section 126 of the Clean Air Act alleging that over 60 power plants, including four that Duke Energy Registrants own and operate, contribute to violations of EPA’s ozone NAAQS in the State of New York. Both Maryland and New York seek EPA orders requiring the states in which the named power plants operate impose more stringent nitrogen oxide (NO_x) emission limitations on the plants. EPA has yet to act on these petitions; litigation has been filed by the State of Maryland in federal district court to compel EPA action. EPA has proposed to the court that it will act on the Maryland petition by the end of 2018. The impact of these petitions could be more stringent requirements for the operation of NO_x emission controls at these plants. The Duke Energy Registrants cannot predict the outcome of these matters.

Global Climate Change

For other information on global climate change and the potential impacts on Duke Energy, see “Other Matters” in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

North Carolina Legislation

For other information on North Carolina legislation and the potential impacts on Duke Energy, see “Other Matters” in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

Nuclear Matters

For other information on nuclear matters and the potential impacts on Duke Energy, see “Other Matters” in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

New Accounting Standards

See Note 1 to the Condensed Consolidated Financial Statements, “Organization and Basis of Presentation,” for a discussion of the impact of new accounting standards.

114

PART I

Off-Balance Sheet Arrangements

During the three months ended March 31, 2018, there were no material changes to Duke Energy’s off-balance sheet arrangements. See Note 11 to the Condensed Consolidated Financial Statements, "Variable Interest Entities," for a discussion of off-balance sheet arrangements regarding Atlantic Coast Pipeline. For additional information on Duke Energy’s off-balance sheet arrangements, see “Off-Balance Sheet Arrangements” in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

Contractual Obligations

Duke Energy enters into contracts that require payment of cash at certain specified periods, based on certain specified minimum quantities and prices. During the three months ended March 31, 2018, there were no material changes in Duke Energy's contractual obligations. For an in-depth discussion of Duke Energy’s contractual obligations, see “Contractual Obligations” and “Quantitative and Qualitative Disclosures about Market Risk” in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Duke Energy’s Annual Report on Form 10-K/A for the year ended December 31, 2017.

Subsequent Events

See Note 17 to the Condensed Consolidated Financial Statements, “Subsequent Events,” for a discussion of subsequent events.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

During the three months ended March 31, 2018, there were no material changes to the Duke Energy Registrants' disclosures about market risk. For an in-depth discussion of the Duke Energy Registrants' market risks, see “Quantitative and Qualitative Disclosures about Market Risk” in Item 7 of the Annual Report on Form 10-K/A for the Duke Energy Registrants.

ITEM 4. CONTROLS AND PROCEDURES

Disclosure Controls and Procedures

Disclosure controls and procedures are controls and other procedures that are designed to ensure that information required to be disclosed by the Duke Energy Registrants in the reports they file or submit under the Securities Exchange Act of 1934 (Exchange Act) are recorded, processed, summarized and reported within the time periods specified by the U.S. Securities and Exchange Commission rules and forms.

Disclosure controls and procedures include, without limitation, controls and procedures designed to provide reasonable assurance that information required to be disclosed by the Duke Energy Registrants in the reports they file or submit under the Exchange Act are accumulated and communicated to management, including the Chief Executive Officer and Chief Financial Officer, as appropriate, to allow timely decisions regarding required disclosure.

Under the supervision and with the participation of management, including the Chief Executive Officer and Chief Financial Officer, the Duke Energy Registrants have evaluated the effectiveness of their disclosure controls and procedures (as such term is defined in Rule 13a-15(e) and 15d-15(e) under the Exchange Act) as of March 31, 2018, and, based upon this evaluation, the Chief Executive Officer and Chief Financial Officer have concluded that these controls and procedures are effective in providing reasonable assurance of compliance.

Changes in Internal Control over Financial Reporting

Under the supervision and with the participation of management, including the Chief Executive Officer and Chief Financial Officer, the Duke Energy Registrants have evaluated changes in internal control over financial reporting (as such term is defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) that occurred during the fiscal quarter ended March 31, 2018, and have concluded no change has materially affected, or is reasonably likely to materially affect, internal control over financial reporting.

115

PART II. OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

For information regarding material legal proceedings, including regulatory and environmental matters, see Note 3, "Regulatory Matters," and Note 4, "Commitments and Contingencies," to the Condensed Consolidated Financial Statements.

Methyl tertiary butyl ether (MTBE) Litigation

On June 19, 2014, the Commonwealth of Pennsylvania filed suit against, among others, Duke Energy Merchants, alleging contamination of waters of the state by MTBE from leaking gasoline storage tanks. MTBE is a gasoline additive intended to increase the oxygen level in gasoline and make it burn cleaner. The lawsuit was moved to federal court and consolidated into an existing multidistrict litigation docket of pending MTBE cases. This suit was settled for an immaterial amount in December 2017 and dismissed in January 2018.

In December 2017, the state of Maryland filed a lawsuit in Baltimore City Circuit Court against Duke Energy Merchants and other defendants alleging contamination of its water supplies from MTBE. Duke Energy cannot predict the outcome of this matter.

ITEM 1A. RISK FACTORS

In addition to the other information set forth in this report, careful consideration should be given to the factors discussed in Part I, “Item 1A. Risk Factors” in the Duke Energy Registrants' Annual Report on Form 10-K/A, which could materially affect the Duke Energy Registrants’ financial condition or future results.

ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

None.

116

PART II

ITEM 6. EXHIBITS

Exhibits filed herein are designated by an asterisk (*). All exhibits not so designated are incorporated by reference to a prior filing, as indicated. Items constituting management contracts or compensatory plans or arrangements are designated by a double asterisk (**). The Company agrees to furnish upon request to the Commission a copy of any omitted schedules or exhibits upon request on all items designated by a triple asterisk (***).

			Duke		Duke	Duke	Duke	Duke
Exhibit		Duke	Energy	Progress	Energy	Energy	Energy	Energy
Number		Energy	Carolinas	Energy	Progress	Florida	Ohio	Indiana	Piedmont
4.1	One Hundredth Supplemental Indenture, dated as of March 1, 2018 (incorporated by reference to Exhibit 4.1 to Registrant's Current Report on Form 8-K filed on March 1, 2018, File No. 1-04928).		X
*4.2	Eighteenth Supplemental Indenture, dated as of March 29, 2018.	X
10.1	Confirmation of Forward Sale Transaction, dated March 6, 2018, between the Company and Credit Suisse Securities (USA) LLC, acting as agent for Credit Suisse Capital LLC (incorporated by reference to Exhibit 10.1 to Registrant's Current Report on Form 8-K filed on March 9, 2018, File No. 1-32853).	X
10.2	Confirmation of Forward Sale Transaction, dated March 6, 2018, between the Company and JPMorgan Chase Bank, National Association, London Branch (incorporated by reference to Exhibit 10.2 to Registrant's Current Report on Form 8-K filed on March 9, 2018, File No. 1-32853).	X
10.3	Additional Confirmation of Forward Sale Transaction, dated March 7, 2018, between the Company and Credit Suisse Securities (USA) LLC, acting as agent for Credit Suisse Capital LLC (incorporated by reference to Exhibit 10.3 to Registrant's Current Report on Form 8-K filed on March 9, 2018, File No. 1-32853).	X
10.4	Additional Confirmation of Forward Sale Transaction, dated March 7, 2018, between the Company and JPMorgan Chase Bank, National Association, London Branch (incorporated by reference to Exhibit 10.4 to Registrant's Current Report on Form 8-K filed on March 9, 2018, File No. 1-32853).	X
*12	Computation of Ratio of Earnings to Fixed Charges – DUKE ENERGY CORPORATION.	X
*31.1.1	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.	X
*31.1.2	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.		X
*31.1.3	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.			X
*31.1.4	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.				X
*31.1.5	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.					X

117

PART II

*31.1.6	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.						X
*31.1.7	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.							X
*31.1.8	Certification of the Chief Executive Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.								X
*31.2.1	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.	X
*31.2.2	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.		X
*31.2.3	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.			X
*31.2.4	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.				X
*31.2.5	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.					X
*31.2.6	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.						X
*31.2.7	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.							X
*31.2.8	Certification of the Chief Financial Officer Pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.								X
*32.1.1	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.	X
*32.1.2	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.		X
*32.1.3	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.			X
*32.1.4	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.				X
*32.1.5	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.					X
*32.1.6	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.						X
*32.1.7	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.							X
*32.1.8	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.								X
*32.2.1	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.	X
*32.2.2	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.		X

118

PART II

*32.2.3	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.			X
*32.2.4	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.				X
*32.2.5	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.					X
*32.2.6	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.						X
*32.2.7	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.							X
*32.2.8	Certification Pursuant to 18 U.S.C. Section 1350, as Adopted Pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.								X
*101.INS	XBRL Instance Document.	X	X	X	X	X	X	X	X
*101.SCH	XBRL Taxonomy Extension Schema Document.	X	X	X	X	X	X	X	X
*101.CAL	XBRL Taxonomy Calculation Linkbase Document.	X	X	X	X	X	X	X	X
*101.LAB	XBRL Taxonomy Label Linkbase Document.	X	X	X	X	X	X	X	X
*101.PRE	XBRL Taxonomy Presentation Linkbase Document.	X	X	X	X	X	X	X	X
*101.DEF	XBRL Taxonomy Definition Linkbase Document.	X	X	X	X	X	X	X	X

The total amount of securities of the registrant or its subsidiaries authorized under any instrument with respect to long-term debt not filed as an exhibit does not exceed 10 percent of the total assets of the registrant and its subsidiaries on a consolidated basis. The registrant agrees, upon request of the SEC, to furnish copies of any or all of such instruments to it.

119

PART II

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrants have duly caused this report to be signed on their behalf by the undersigned thereunto duly authorized.

		DUKE ENERGY CORPORATION DUKE ENERGY CAROLINAS, LLC PROGRESS ENERGY, INC. DUKE ENERGY PROGRESS, LLC DUKE ENERGY FLORIDA, LLC DUKE ENERGY OHIO, INC. DUKE ENERGY INDIANA, LLC PIEDMONT NATURAL GAS COMPANY, INC.
Date:	May 10, 2018	/s/ STEVEN K. YOUNG
		Steven K. Young Executive Vice President and Chief Financial Officer (Principal Financial Officer)
Date:	May 10, 2018	/s/ WILLIAM E. CURRENS JR.
		William E. Currens Jr. Senior Vice President, Chief Accounting Officer and Controller (Principal Accounting Officer)

120

EX-4.2

EXHIBIT 4.2

DUKE ENERGY CORPORATION

TO

THE BANK OF NEW YORK MELLON TRUST COMPANY, N.A.

Trustee

Eighteenth Supplemental Indenture Dated as of March 29, 2018

$250,000,000 3.95% SENIOR NOTES DUE 2025

EXHIBIT 4.2

TABLE OF CONTENTS¹ 

ARTICLE I

3.95% SENIOR NOTES DUE 2025

Section 1.01.    Establishment.    1

Section 1.02.    Definitions    2

Section 1.03.    Payment of Principal and Interest    2

Section 1.04.    Denominations    3

Section 1.05.    Global Securities    3

Section 1.06.    Redemption    4

Section 1.07.    Paying Agent    6

Section 1.08.    Legends    6

ARTICLE II MISCELLANEOUS PROVISIONS

Section 2.01.    Recitals by the Corporation    6

Section 2.02.    Ratification and Incorporation of Original Indenture    6

Section 2.03.    Executed in Counterparts    6

Exhibit A – Form of 3.95% Senior Note Due 2025 Exhibit B – Certificate of Authentication

Exhibit C – Certificate of Transfer

Exhibit D – Schedule of Increases or Decreases in Global Security

1 This Table of Contents does not constitute part of the Indenture or have any bearing upon the interpretation of any of its terms and provisions.

i

EXHIBIT 4.2

THIS EIGHTEENTH SUPPLEMENTAL INDENTURE is made as of the 29^th day of March, 2018, by and among DUKE ENERGY CORPORATION, a Delaware corporation, having its principal office at 550 South Tryon Street, Charlotte, North Carolina 28202-1803 (the “Corporation”), and The Bank of New York Mellon Trust Company, N.A. (formerly known as The Bank of New York Trust Company, N.A.), a national banking association, as Trustee (herein called the “Trustee”).

WITNESSETH:

WHEREAS, the Corporation has heretofore entered into an Indenture, dated as of June 3, 2008 (the “Original Indenture”), with The Bank of New York Mellon Trust Company, N.A., as Trustee;

WHEREAS, the Original Indenture is incorporated herein by this reference and the Original Indenture, as it may be amended and supplemented to the date hereof, including by this Eighteenth Supplemental Indenture, is herein called the “Indenture”;

WHEREAS, under the Indenture, a new series of Securities may at any time be established in accordance with the provisions of the Indenture and the terms of such series may be described by a supplemental indenture executed by the Corporation and the Trustee;

WHEREAS, the Corporation hereby proposes to create under the Indenture one additional series of Securities;

WHEREAS, additional Securities of other series hereafter established, except as may be limited in the Indenture as at the time supplemented and modified, may be issued from time to time pursuant to the Indenture as at the time supplemented and modified; and

WHEREAS, all conditions necessary to authorize the execution and delivery of this Eighteenth Supplemental Indenture and to make it a valid and binding obligation of the Corporation have been done or performed.

NOW, THEREFORE, in consideration of the agreements and obligations set forth herein and for other good and valuable consideration, the sufficiency of which is hereby acknowledged, the parties hereto hereby agree as follows:

ARTICLE I

3.95% SENIOR NOTES DUE 2025

Section 1.01. Establishment. There is hereby established a new series of Securities to be issued under the Indenture, to be designated as the Corporation’s 3.95% Senior Notes due 2025 (the “2025 Notes”).

There are to be authenticated and delivered initially $250,000,000 principal amount of the 2025 Notes, and no further 2025 Notes shall be authenticated and delivered except as provided by Section 304, 305, 306, 906 or 1106 of the Original Indenture and the last paragraph of Section 301 thereof. The 2025 Notes shall be issued in fully registered form without coupons.

The 2025 Notes shall be in substantially the form set out in Exhibit A hereto, and the form of the Trustee’s Certificate of Authentication for the 2025 Notes shall be in substantially the form set forth in Exhibit B hereto.

EXHIBIT 4.2

Each 2025 Note shall be dated the date of authentication thereof and shall bear interest from the date of original issuance thereof or from the most recent Interest Payment Date to which interest has been paid or duly provided for.

Section 1.02. Definitions. The following defined terms used in this Article I shall, unless the context otherwise requires, have the meanings specified below for purposes of the 2025 Notes. Capitalized terms used herein for which no definition is provided herein shall have the meanings set forth in the Original Indenture.

“Business Day” means any day other than a Saturday or Sunday that is neither a Legal Holiday nor a day on which banking institutions in New York, New York are authorized or required by law, regulation or executive order to close, or a day on which the Corporate Trust Office is closed for business.

“Interest Payment Date” means each April 15 and October 15 of each year, commencing on October 15, 2018.

“Legal Holiday” means any day that is a legal holiday in New York, New York. “Original Issue Date” means March 29, 2018.

“Regular Record Date” means, with respect to each Interest Payment Date, the close of business on the 15th calendar day prior to such Interest Payment Date (whether or not a Business Day).

“Stated Maturity” means April 15, 2025.

Section 1.03. Payment of Principal and Interest. The principal of the 2025 Notes shall be due at Stated Maturity (unless earlier redeemed). The unpaid principal amount of the 2025 Notes shall bear interest at the rate of 3.95% per annum until paid or duly provided for, such interest to accrue from March 29, 2018 or from the most recent Interest Payment Date to which interest has been paid or duly provided for. Interest shall be paid semi-annually in arrears on each Interest Payment Date to the Person or Persons in whose name the 2025 Notes are registered on the Regular Record Date for such Interest Payment Date; provided that interest payable at the Stated Maturity or on a Redemption Date as provided herein shall be paid to the Person to whom principal is payable. Any such interest that is not so punctually paid or duly provided for shall forthwith cease to be payable to the Holders on such Regular Record Date and may either be paid to the Person or Persons in whose name the 2025 Notes are registered at the close of business on a Special Record Date for the payment of such defaulted interest to be fixed by the Trustee (“Special Record Date”), notice whereof shall be given to Holders of the 2025 Notes not less than ten

(10) days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange, if any, on which the 2025 Notes may be listed, and upon such notice as may be required by any such exchange, all as more fully provided in the Original Indenture.

Payments of interest on the 2025 Notes shall include interest accrued to but excluding the respective Interest Payment Dates. Interest payments for the 2025 Notes shall be computed and paid on the basis of a 360-day year consisting of twelve 30-day months. In the event that any date on which interest is payable on the 2025 Notes is not a Business Day, then payment of the interest payable on such date shall be made on the next succeeding day that is a Business Day (and without any interest or payment in respect of any such delay) with the same force and effect as if made on the date the payment was originally payable.

2

EXHIBIT 4.2

Payment of principal of, premium, if any, and interest on the 2025 Notes shall be made in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts. Payments of principal of, premium, if any, and interest on 2025 Notes represented by a Global Security shall be made by wire transfer of immediately available funds to the Holder of such Global Security. If any of the 2025 Notes are no longer represented by a Global Security,

(i)payments of principal, premium, if any, and interest due at the Stated Maturity or earlier redemption of such 2025 Notes shall be made at the office of the Paying Agent upon surrender of such 2025 Notes to the Paying Agent and (ii) payments of interest shall be made, at the option of the Corporation, subject to such surrender where applicable, by (A) check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register or (B) wire transfer at such place and to such account at a banking institution in the United States as may be designated in writing to the Trustee at least sixteen (16) days prior to the date for payment by the Person entitled thereto.

Section 1.04. Denominations. The 2025 Notes shall be issued in denominations of $2,000 or any integral multiple of $1,000 in excess thereof.

Section 1.05. Global Securities. The 2025 Notes shall initially be issued in the form of one or more Global Securities registered in the name of the Depositary (which initially shall be The Depository Trust Company) or its nominee. The 2025 Notes will be initially issued pursuant to an exemption or exemptions from the registration requirements of the Securities Act of 1933, as amended (the “Securities Act”). Beneficial interests in the 2025 Notes offered and sold to “qualified institutional buyers” (as defined in Rule 144A under the Securities Act) in reliance upon Rule 144A under the Securities Act shall be represented by one or more separate Global Securities (each, a “Rule 144A Global Note”). Each Rule 144A Global Note shall bear the non-registration legend in substantially the form set forth in Exhibit A hereto (the “Rule 144A Legend”). Beneficial interests in the 2025 Notes offered and sold to purchasers outside of the United States pursuant to Regulation S under the Securities Act shall be represented by one or more separate Global Securities (each, a “Regulation S Global Note”) and shall bear the Regulation S legend in substantially the form set forth in Exhibit A hereto (the “Regulation S Legend”).

Except under the limited circumstances described below, 2025 Notes represented by such Global Security or Global Securities shall not be exchangeable for, and shall not otherwise be issuable as, 2025 Notes in definitive form. The Global Securities described in this Article I may not be transferred except by the Depositary to a nominee of the Depositary or by a nominee of the Depositary to the Depositary or another nominee of the Depositary or to a successor Depositary or its nominee. Nothing in the Indenture or the 2025 Notes shall be construed to require the Corporation to register any 2025 Note under the Securities Act, or to make any transfer of such 2025 Note in violation of applicable law.

A Global Security representing the 2025 Notes shall be exchangeable for 2025 Notes registered in the names of persons other than the Depositary or its nominee only if (i) the Depositary notifies the Corporation that it is unwilling or unable to continue as a Depositary for such Global Security and no successor Depositary shall have been appointed by the Corporation within 90 days of receipt by the Corporation of such notification, or if at any time the Depositary ceases to be a clearing agency registered under the Exchange Act at a time when the Depositary is required to be so registered to act as such Depositary and no successor Depositary shall have been appointed by the Corporation within 90 days after it becomes aware of such cessation, (ii) an Event of Default has occurred and is continuing with respect to the 2025 Notes and beneficial owners of a majority in aggregate principal amount of the 2025 Notes represented by Global Securities advise the Depositary to cease acting as Depositary, or (iii) the Corporation in its sole discretion, and subject to the procedures of the Depositary, determines that such Global Security shall be so exchangeable. Any Global Security that is exchangeable pursuant to the preceding sentence shall be exchangeable for 2025 Notes registered in such names as the Depositary shall direct.

3

EXHIBIT 4.2

A Rule 144A Global Note may not be transferred on the Security Register except in compliance with the restrictions on transfer contained in the Rule 144A Legend and upon receipt by the Security Registrar of a completed and executed Certificate of Transfer in the form contained in Exhibit C hereto. Prior to the expiration of 40 days beginning on and including the later of (i) the day on which the offering of the 2025 Notes commences and (ii) the Original Issue Date of the 2025 Notes, a Regulation S Global Note may not be transferred on the Security Register except in compliance with the restrictions on transfer contained in the Regulation S Legend and upon receipt by the Security Registrar of a completed and executed Certificate of Transfer in the form contained in Exhibit C hereto.

Any beneficial interest in one of the Global Securities that is transferred to a person who takes delivery in the form of an interest in another Global Security of that series will, upon transfer, cease to be an interest in the initial Global Security of that series and will become an interest in the other Global Security of that series and, accordingly, will thereafter be subject to all transfer restrictions, if any, and other procedures applicable to beneficial interests in such other Global Security of that series for as long as it remains such an interest.

Neither the Trustee or the Security Registrar shall have any obligation or duty to monitor, determine or inquire as to compliance with any restrictions on transfer imposed under the Indenture or under applicable law with respect to any transfer of any interest in any Global Security (including any transfers between or among Depositary participants, members or holders of any Global Security) other than, in connection with a registration of transfer of the 2025 Note on the Security Register, to require delivery of such certificates and other documentation or evidence as are expressly required by, and to do so if and when expressly required by, the terms of the Indenture, and to examine the same to determine substantial compliance as to form with the express requirements hereof. Transfers of beneficial interests between a Rule 144A Global Note and a Regulation S Global Note, and other transfers relating to beneficial interests in the Global Securities, shall be reflected by endorsements of the Trustee, as custodian for DTC, on the schedule attached to such Rule 144A Global Note and Regulation S Global Note. Accordingly, in connection with any such transfer, appropriate adjustments will be made to reflect a decrease in the principal amount of a Regulation S Global Note and a corresponding increase in the principal amount of a Rule 144A Global Note or vice versa, as applicable. Neither the Corporation nor the Trustee shall have any liability for acts or omissions of any Depositary, for any Depositary records of beneficial interest, for any transactions between the Depositary, any participant member of the Depositary and/or beneficial owner of any interest in any 2025 Notes, or in respect of any transfers effected by the Depositary or by any participant member of the Depositary or any beneficial owner of any interest in any 2025 Notes held through any such participant member of the Depositary.

No service charge shall be made for any registration of transfer or exchange of the 2025 Notes, but the Corporation may require payment of a sum sufficient to cover any tax or other governmental charge that may be imposed in connection therewith.

Section 1.06. Redemption. At any time before February 15, 2025 (the “Par Call Date”), the 2025 Notes shall be redeemable, in whole or in part and from time to time, at the option of the Corporation, on any date (a “Redemption Date”), at a redemption price equal to the greater of (i) 100% of the principal amount of the 2025 Notes being redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest on the 2025 Notes being redeemed that would be due if the 2025 Notes matured on the Par Call Date (exclusive of interest accrued to such Redemption Date) discounted to such Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 20 basis points, plus, in either case, accrued and unpaid interest on the principal amount of the 2025 Notes being redeemed to, but excluding, such Redemption Date.

4

EXHIBIT 4.2

At any time on or after the Par Call Date, the 2025 Notes shall be redeemable, in whole or in part and from time to time, at the option of the Corporation, at a redemption price equal to 100% of the principal amount of the 2025 Notes being redeemed plus accrued and unpaid interest on the principal amount being redeemed to, but excluding, such Redemption Date.

For purposes of the first paragraph of this Section 1.06, the following terms have the following meanings:

“Comparable Treasury Issue” means the United States Treasury security selected by the Quotation Agent as having an actual or interpolated maturity comparable to the remaining term of the 2025 Notes to be redeemed (assuming, for this purpose, that the 2025 Notes matured on the Par Call Date), that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such 2025 Notes.

“Comparable Treasury Price” means, with respect to any Redemption Date for the 2025 Notes,

(1)the average of the Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and lowest of such Reference Treasury Dealer Quotations, or (2) if fewer than four of such Reference Treasury Dealer Quotations are obtained, the average of all such Reference Treasury Dealer Quotations as determined by the Corporation.

“Quotation Agent” means a Reference Treasury Dealer appointed by the Corporation.

“Reference Treasury Dealer” means Morgan Stanley & Co. LLC, plus four other financial institutions appointed by the Corporation at the time of any redemption of the 2025 Notes, or their respective affiliates or successors, each of which is a primary U.S. Government securities dealer in the United States (a “Primary Treasury Dealer”); provided, however, that if any of the foregoing or their affiliates or successors shall cease to be a Primary Treasury Dealer, the Corporation will substitute therefor another Primary Treasury Dealer.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date for the 2025 Notes, the average, as determined by the Quotation Agent, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Quotation Agent by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.

“Treasury Rate” means, with respect to any Redemption Date for the 2025 Notes, the rate per annum equal to the semi-annual equivalent yield to maturity or interpolated maturity (on a day count basis) of the Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such Redemption Date. The Treasury Rate shall be calculated by the Corporation on the third Business Day preceding the Redemption Date.

The Corporation shall notify the Trustee of the redemption price with respect to any redemption of the 2025 Notes occurring before the Par Call Date promptly after the calculation thereof. The Trustee shall not be responsible for calculating said redemption price.

If less than all of the 2025 Notes are to be redeemed, the Trustee shall select the 2025 Notes or portions of 2025 Notes to be redeemed by such method as the Trustee shall deem fair and appropriate. The Trustee may select for redemption 2025 Notes and portions of 2025 Notes in amounts of

$2,000 or any integral multiple of $1,000 in excess thereof. As long as the 2025 Notes are represented by

5

EXHIBIT 4.2

Global Securities, beneficial interests in such Notes shall be selected for redemption by the Depositary in accordance with its standard procedures therefor.

The 2025 Notes shall not have a sinking fund.

Section 1.07. Paying Agent. The Trustee shall initially serve as Paying Agent with respect to the 2025 Notes, with the Place of Payment initially being the Corporate Trust Office.

Section 1.08. Legends. Each 2025 Note, whether in a global form or in a definitive form, shall bear the Rule 144A Legend, or the Regulation S Legend, as applicable, in substantially the form set forth in Exhibit A hereto.

ARTICLE II MISCELLANEOUS PROVISIONS

Section 2.01.    Recitals by the Corporation.    The recitals in this Eighteenth Supplemental

Indenture are made by the Corporation only and not by the Trustee, and all of the provisions contained in the Original Indenture in respect of the rights, privileges, immunities, powers and duties of the Trustee shall be applicable in respect of the 2025 Notes and this Eighteenth Supplemental Indenture as fully and with like effect as if set forth herein in full.

Section 2.02. Ratification and Incorporation of Original Indenture. As supplemented hereby, the Original Indenture is in all respects ratified and confirmed, and the Original Indenture and this Eighteenth Supplemental Indenture shall be read, taken and construed as one and the same instrument.

Section 2.03. Executed in Counterparts. This Eighteenth Supplemental Indenture may be executed in several counterparts, each of which shall be deemed to be an original, and such counterparts shall together constitute but one and the same instrument.

6

EXHIBIT 4.2

IN WITNESS WHEREOF, each party hereto has caused this instrument to be signed in its name and behalf by its duly authorized officer, all as of the day and year first above written.

Duke Energy Corporation

By: /s/ JOHN L. SULLIVAN, III

Name: John L. Sullivan, III

Title: Assistant Treasurer

The Bank of New York Mellon Trust Company,

N.A as Trustee

By: /s/ LAWRENCE M. KUSCH

Name: Lawrence M. Kusch

Title: Vice President

[Signature Page to Eighteenth Supplemental Indenture]

EXHIBIT 4.2

EXHIBIT A [DEPOSITARY LEGEND]

[UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY (55 WATER STREET, NEW YORK, NEW YORK) TO THE CORPORATION OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT AND ANY SECURITY ISSUED IS REGISTERED IN THE NAME OF CEDE & CO. OR SUCH OTHER NAME AS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY AND ANY PAYMENT HEREON IS MADE TO CEDE & CO., ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY A PERSON IS WRONGFUL SINCE THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.]

[RULE 144 A LEGEND]

[NEITHER THIS SECURITY NOR ANY BENEFICIAL INTEREST HEREIN HAS BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”). EACH HOLDER HEREOF, AND EACH OWNER OF A BENEFICIAL INTEREST HEREIN, BY PURCHASING THIS SECURITY, AGREES FOR THE BENEFIT OF DUKE ENERGY CORPORATION (THE “CORPORATION”) THAT THIS SECURITY MAY NOT BE RESOLD, PLEDGED OR OTHERWISE TRANSFERRED PRIOR TO THE DATE WHICH IS SIX MONTHS (IF ALL APPLICABLE CONDITIONS TO SUCH RESALE UNDER RULE 144 UNDER THE SECURITIES ACT (“RULE 144A”) (OR ANY SUCCESSOR PROVISION THEREOF) ARE SATISFIED) AFTER THE LATER OF THE ORIGINAL ISSUANCE DATE THEREOF, THE ISSUANCE DATE OF ANY SUBSEQUENT ISSUANCE OF ADDITIONAL SECURITIES OF THE SAME SERIES AND THE LAST DATE ON WHICH THE CORPORATION OR ANY AFFILIATE THEREOF WAS THE OWNER OF THIS SECURITY OR THE EXPIRATION OF SUCH SHORTER PERIOD AS MAY BE PRESCRIBED BY SUCH RULE 144 (OR SUCH SUCCESSOR PROVISION) PERMITTING RESALES OF THIS SECURITY WITHOUT ANY CONDITIONS (THE “RESALE RESTRICTION TERMINATION DATE”) OTHER THAN (A)(1) TO THE CORPORATION, (2) IN A TRANSACTION ENTITLED TO AN EXEMPTION FROM REGISTRATION PROVIDED BY RULE

144 UNDER THE SECURITIES ACT, (3) SO LONG AS THIS SECURITY IS ELIGIBLE FOR RESALE PURSUANT TO RULE 144A, TO A PERSON WHOM THE SELLER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL BUYER WITHIN THE MEANING OF RULE 144A PURCHASING FOR ITS OWN ACCOUNT OR FOR THE ACCOUNT OF A QUALIFIED INSTITUTIONAL BUYER TO WHOM NOTICE IS GIVEN THAT THE RESALE, PLEDGE OR OTHER TRANSFER IS BEING MADE IN RELIANCE ON RULE 144A (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE CERTIFICATE OF TRANSFER ATTACHED TO THIS SECURITY), (4) IN AN OFFSHORE TRANSACTION IN ACCORDANCE WITH RULE 903 OR 904 OF REGULATION S UNDER THE SECURITIES ACT (AS INDICATED BY THE BOX CHECKED BY THE TRANSFEROR ON THE CERTIFICATE OF TRANSFER ATTACHED TO THIS SECURITY), (5) IN ACCORDANCE WITH ANOTHER APPLICABLE EXEMPTION FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT (AND BASED UPON AN OPINION OF COUNSEL ACCEPTABLE TO THE CORPORATION), OR (6) PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT AND (B) IN EACH CASE IN ACCORDANCE WITH ANY APPLICABLE SECURITIES LAWS OF ANY STATE OF THE UNITED STATES. THE FOREGOING RESTRICTIONS ON RESALE WILL NOT APPLY SUBSEQUENT TO THE RESALE RESTRICTION TERMINATION DATE. THE HOLDER HEREOF, BY PURCHASING THIS SECURITY, REPRESENTS AND AGREES FOR THE BENEFIT OF THE CORPORATION THAT IT IS (i) A QUALIFIED INSTITUTIONAL BUYER WITHIN THE MEANING OF RULE 144A

A-1

EXHIBIT 4.2

OR (ii) A NON-U.S. PERSON OUTSIDE THE UNITED STATES WITHIN THE MEANING OF, OR AN ACCOUNT SATISFYING THE REQUIREMENTS OF, PARAGRAPH (k)(2) OF RULE 902 UNDER REGULATION S UNDER THE SECURITIES ACT. THE HOLDER OF THIS SECURITY ACKNOWLEDGES THAT THE CORPORATION RESERVES THE RIGHT PRIOR TO ANY OFFER, SALE OR OTHER TRANSFER (1) PURSUANT TO CLAUSE (A)(2) PRIOR TO THE RESALE RESTRICTION TERMINATION DATE TO REQUIRE THE DELIVERY OF AN OPINION OF COUNSEL, CERTIFICATIONS OR OTHER INFORMATION SATISFACTORY TO THE CORPORATION AND (2) IN EACH OF THE FOREGOING CASES, TO REQUIRE THAT A CERTIFICATE AS TO COMPLIANCE WITH CERTAIN CONDITIONS TO TRANSFER IS COMPLETED AND DELIVERED BY THE TRANSFEROR TO THE CORPORATION.]

[REGULATION S LEGEND]

[THE SECURITIES COVERED HEREBY HAVE NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), AND MAY NOT BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR BENEFIT OF, U.S. PERSONS (I) AS PART OF THEIR DISTRIBUTION AT ANY TIME OR

(II) OTHERWISE UNTIL 40 DAYS AFTER THE LATER OF THE DATE OF THE COMMENCEMENT OF THE OFFERING OF THE SECURITIES AND THE DATE OF ORIGINAL ISSUANCE OF THE SECURITIES, EXCEPT IN EITHER CASE IN ACCORDANCE WITH REGULATION S OR RULE 144A UNDER THE SECURITIES ACT OR ANY OTHER AVAILABLE EXEMPTION FROM REGISTRATION UNDER THE SECURITIES ACT. TERMS USED ABOVE HAVE THE MEANINGS GIVEN TO THEM BY REGULATION S.]

FORM OF

3.95% SENIOR NOTE DUE 2025

No.    Rule 144A CUSIP No. 26441C AZ8

Regulation S CUSIP No. U2648M AD4

DUKE ENERGY CORPORATION 3.95% SENIOR NOTE DUE 2025

Principal Amount: $

Regular Record Date: Close of business on the 15th calendar day prior to the relevant Interest Payment Date (whether or not a Business Day)

Original Issue Date: March 29, 2018

Stated Maturity: April 15, 2025

Interest Payment Dates: Semi-annually on April 15 and October 15 of each year, commencing on October 15, 2018

Interest Rate: 3.95% per annum

Authorized Denomination: $2,000 or any integral multiple of $1,000 in excess thereof

Duke Energy Corporation, a Delaware corporation (the “Corporation”, which term includes any successor corporation under the Indenture referred to on the reverse hereof), for value received, hereby

A-2

EXHIBIT 4.2

promises to pay to        , or registered assigns, the principal sum of    DOLLARS ($    ) on the Stated Maturity shown above and to pay interest thereon from the Original Issue Date shown above, or from the most recent Interest Payment Date to which interest has been paid or duly provided for, semi-annually in arrears on each Interest Payment Date as specified above, commencing on October 15, 2018 and on the Stated Maturity at the rate per annum shown above until the principal hereof is paid or made available for payment and at such rate on any overdue principal and on any overdue installment of interest. The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date (other than an Interest Payment Date that is the Stated Maturity or a Redemption Date) will, as provided in the Indenture, be paid to the Person in whose name this 3.95% Senior Note due 2025 (this “Security”) is registered on the Regular Record Date as specified above next preceding such Interest Payment Date; provided that any interest payable at Stated Maturity or on a Redemption Date will be paid to the Person to whom principal is payable. Except as otherwise provided in the Indenture, any such interest not so punctually paid or duly provided for will forthwith cease to be payable to the Holder on such Regular Record Date and may either be paid to the Person in whose name this Security is registered at the close of business on a Special Record Date for the payment of such Defaulted Interest to be fixed by the Trustee, notice whereof shall be given to Holders of Securities of this series not less than 10 days prior to such Special Record Date, or be paid at any time in any other lawful manner not inconsistent with the requirements of any securities exchange, if any, on which the Securities shall be listed, and upon such notice as may be required by any such exchange, all as more fully provided in the Indenture.

Payments of interest on this Security will include interest accrued to but excluding the respective Interest Payment Dates. Interest payments for this Security shall be computed and paid on the basis of a 360-day year consisting of twelve 30-day months and will accrue from March 29, 2018 or from the most recent Interest Payment Date to which interest has been paid or duly provided for. In the event that any date on which interest is payable on this Security is not a Business Day, then payment of the interest payable on such date will be made on the next succeeding day that is a Business Day (and without any interest or payment in respect of any such delay) with the same force and effect as if made on the date the payment was originally payable. “Business Day” means any day other than a Saturday or Sunday that is neither a Legal Holiday nor a day on which banking institutions in New York, New York are authorized or required by law, regulation or executive order to close, or a day on which the Corporate Trust Office is closed for business. “Legal Holiday” means any day that is a legal holiday in New York, New York.

Payment of principal of, premium, if any, and interest on the Securities of this series shall be made in such coin or currency of the United States of America as at the time of payment is legal tender for payment of public and private debts. Payments of principal of, premium, if any, and interest on the Securities of this series represented by a Global Security shall be made by wire transfer of immediately available funds to the Holder of such Global Security. If any of the Securities of this series are no longer represented by a Global Security, (i) payments of principal, premium, if any, and interest due at the Stated Maturity or earlier redemption of such Securities shall be made at the office of the Paying Agent upon surrender of such Securities to the Paying Agent, and (ii) payments of interest shall be made, at the option of the Corporation, subject to such surrender where applicable, by (A) check mailed to the address of the Person entitled thereto as such address shall appear in the Security Register or (B) wire transfer at such place and to such account at a banking institution in the United States as may be designated in writing to the Trustee at least sixteen (16) days prior to the date for payment by the Person entitled thereto.

At any time before February 15, 2025 (the “Par Call Date”), the Securities of this series shall be redeemable, in whole or in part and from time to time, at the option of the Corporation, on any date (a “Redemption Date”), at a redemption price equal to the greater of (i) 100% of the principal amount of the Securities of this series being redeemed and (ii) the sum of the present values of the remaining scheduled payments of principal and interest on the Securities of this series being redeemed that would be due if this

A-3

EXHIBIT 4.2

Security matured on the Par Call Date (exclusive of interest accrued to such Redemption Date), discounted to such Redemption Date on a semi-annual basis (assuming a 360-day year consisting of twelve 30-day months) at the Treasury Rate plus 20 basis points, plus, in either case, accrued and unpaid interest on the principal amount being redeemed to, but excluding, such Redemption Date.

At any time on or after the Par Call Date, the Securities of this series shall be redeemable, in whole or in part and from time to time, at the option of the Corporation, at a redemption price equal to 100% of the principal amount of the Securities of this series being redeemed plus accrued and unpaid interest on the principal amount being redeemed to, but excluding, such Redemption Date.

For purposes of the second preceding paragraph, the following terms have the following meanings:

“Comparable Treasury Issue” means the United States Treasury security selected by the Quotation Agent as having an actual or interpolated maturity comparable to the remaining term of the Securities of this series to be redeemed (assuming, for this purpose, that this Security matured on the Par Call Date), that would be utilized, at the time of selection and in accordance with customary financial practice, in pricing new issues of corporate debt securities of comparable maturity to the remaining term of such Securities of this series.

“Comparable Treasury Price” means, with respect to any Redemption Date for the Securities of this series, (1) the average of the Reference Treasury Dealer Quotations for such Redemption Date, after excluding the highest and lowest of such Reference Treasury Dealer Quotations, or (2) if fewer than four of such Reference Treasury Dealer Quotations are obtained, the average of all such Reference Treasury Dealer Quotations as determined by the Corporation.

“Quotation Agent” means a Reference Treasury Dealer appointed by the Corporation.

“Reference Treasury Dealer” means Morgan Stanley & Co. LLC, plus four other financial institutions appointed by the Corporation at the time of any redemption of the Securities of this series, or their respective affiliates or successors, each of which is a primary U.S. Government securities dealer in the United States (a “Primary Treasury Dealer”); provided, however, that if any of the foregoing or their affiliates or successors shall cease to be a Primary Treasury Dealer, the Corporation will substitute therefor another Primary Treasury Dealer.

“Reference Treasury Dealer Quotations” means, with respect to each Reference Treasury Dealer and any Redemption Date for the Securities of this series, the average, as determined by the Quotation Agent, of the bid and asked prices for the Comparable Treasury Issue (expressed in each case as a percentage of its principal amount) quoted in writing to the Quotation Agent by such Reference Treasury Dealer at 5:00 p.m., New York City time, on the third Business Day preceding such Redemption Date.

“Treasury Rate” means, with respect to any Redemption Date for the Securities of this series, the rate per annum equal to the semi-annual equivalent yield to maturity or interpolated maturity (on a day count basis) of the Comparable Treasury Issue, assuming a price for the Comparable Treasury Issue (expressed as a percentage of its principal amount) equal to the Comparable Treasury Price for such Redemption Date. The Treasury Rate shall be calculated by the Corporation on the third Business Day preceding the Redemption Date.

The Corporation shall notify the Trustee of the redemption price with respect to any redemption of the Securities of this series occurring before the Par Call Date promptly after the calculation thereof. The Trustee shall not be responsible for calculating said redemption price.

A-4

EXHIBIT 4.2

Notice of any redemption by the Corporation will be mailed (or, as long as the Securities of this series are represented by one or more Global Securities, transmitted in accordance with the Depositary’s standard procedures therefor) at least 10 days but not more than 60 days before any Redemption Date to each Holder of Securities of this series to be redeemed. If Notice of a redemption is provided and funds are deposited as required, interest will cease to accrue on and after the Redemption Date on the Securities of this series or portions of Securities of this series called for redemption. In the event that any Redemption Date is not a Business Day, the Corporation will pay the redemption price on the next Business Day without any interest or other payment in respect of any such delay. If less than all the Securities of this series are to be redeemed at the option of the Corporation, the Trustee shall select, in such manner as it shall deem fair and appropriate, the Securities of this series to be redeemed in whole or in part. The Trustee may select for redemption Securities of this series and portions of the Securities of this series in amounts of $2,000 or any integral multiple of $1,000 in excess thereof. As long as the Securities of this series are represented by Global Securities, beneficial interests in such Securities shall be selected for redemption by the Depositary in accordance with its standard procedures therefor.

In the event of redemption of this Security in part only, a new Security or Securities of this series and of like tenor for the unredeemed portion hereof will be issued in the name of the Holder hereof upon the surrender hereof.

The Securities of this series shall not have a sinking fund.

The Securities of this series shall constitute the direct unsecured and unsubordinated debt obligations of the Corporation and shall rank equally in priority with the Corporation’s existing and future unsecured and unsubordinated indebtedness.

REFERENCE IS HEREBY MADE TO THE FURTHER PROVISIONS OF THIS SECURITY SET FORTH ON THE REVERSE HEREOF, WHICH FURTHER PROVISIONS SHALL FOR ALL PURPOSES HAVE THE SAME EFFECT AS IF SET FORTH AT THIS PLACE.

Unless the certificate of authentication hereon has been executed by the Trustee by manual signature, this Security shall not be entitled to any benefit under the Indenture or be valid or obligatory for any purpose.

A-5

EXHIBIT 4.2

IN WITNESS WHEREOF, the Corporation has caused this instrument to be duly executed as of March 29, 2018.

Duke Energy Corporation

By:

Name:

Title:

A-6

EXHIBIT 4.2

CERTIFICATE OF AUTHENTICATION

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture.

Dated: March 29, 2018	The Bank of New York Mellon Trust Company,
	N.A., as Trustee
	By:
	Authorized Signatory

A-7

EXHIBIT 4.2

(Reverse Side of Security)

This 3.95% Senior Note due 2025 is one of a duly authorized issue of Securities of the Corporation (the “Securities”), issued and issuable in one or more series under an Indenture, dated as of June 3, 2008, as supplemented (the “Indenture”), between the Corporation and The Bank of New York Mellon Trust Company, N.A. (formerly known as The Bank of New York Trust Company, N.A.), as Trustee (the “Trustee,” which term includes any successor trustee under the Indenture), to which Indenture and all indentures supplemental thereto reference is hereby made for a statement of the respective rights, limitation of rights, duties and immunities thereunder of the Corporation, the Trustee and the Holders of the Securities issued thereunder and of the terms upon which said Securities are, and are to be, authenticated and delivered. This Security is one of the series designated on the face hereof as 3.95% Senior Notes due 2025 initially in the aggregate principal amount of $250,000,000. Capitalized terms used herein for which no definition is provided herein shall have the meanings set forth in the Indenture.

If an Event of Default with respect to the Securities of this series shall occur and be continuing, the principal of the Securities of this series may be declared due and payable in the manner, with the effect and subject to the conditions provided in the Indenture.

The Indenture permits, with certain exceptions as therein provided, the amendment thereof and the modification of the rights and obligations of the Corporation and the rights of the Holders of the Securities of all series affected under the Indenture at any time by the Corporation and the Trustee with the consent of the Holders of not less than a majority in principal amount of the Outstanding Securities of all series affected thereby (voting as one class). The Indenture contains provisions permitting the Holders of not less than a majority in principal amount of the Outstanding Securities of all series with respect to which a default under the Indenture shall have occurred and be continuing (voting as one class), on behalf of the Holders of the Securities of all such series, to waive, with certain exceptions, such default under the Indenture and its consequences. The Indenture also permits the Holders of not less than a majority in principal amount of the Securities of each series at the time Outstanding, on behalf of the Holders of all Securities of such series, to waive compliance by the Corporation with certain provisions of the Indenture affecting such series. Any such consent or waiver by the Holder of this Security shall be conclusive and binding upon such Holder and upon all future Holders of this Security and of any Security issued upon the registration of transfer hereof or in exchange hereof or in lieu hereof, whether or not notation of such consent or waiver is made upon this Security.

No reference herein to the Indenture and no provision of this Security or of the Indenture shall alter or impair the obligation of the Corporation, which is absolute and unconditional, to pay the principal of and interest on this Security at the times, place and rate, and in the coin or currency, herein prescribed.

As provided in the Indenture and subject to certain limitations therein set forth, the transfer of this Security is registrable in the Security Register, upon surrender of this Security for registration of transfer at the office or agency of the Corporation for such purpose, duly endorsed by, or accompanied by a written instrument of transfer in form satisfactory to the Corporation and the Security Registrar and duly executed by, the Holder hereof or his attorney duly authorized in writing, together with the completed and executed Certificate of Transfer attached hereto, and thereupon one or more new Securities of this series, of authorized denominations and of like tenor and for the same aggregate principal amount, will be issued to the designated transferee or transferees. No service charge shall be made for any such registration of transfer or exchange, but the Corporation may require payment of a sum sufficient to cover any tax or other governmental charge payable in connection therewith.

A-8

EXHIBIT 4.2

The Indenture contains provisions for defeasance at any time of the entire indebtedness of the Securities of this series and for covenant defeasance at any time of certain covenants in the Indenture upon compliance with certain conditions set forth in the Indenture.

Prior to due presentment of this Security for registration of transfer, the Corporation, the Trustee and any agent of the Corporation or the Trustee may treat the Person in whose name this Security is registered as the owner hereof for all purposes, whether or not this Security be overdue, and neither the Corporation, the Trustee nor any such agent shall be affected by notice to the contrary.

The Securities of this series are issuable only in registered form without coupons in denominations of $2,000 or any integral multiple of $1,000 in excess thereof. As provided in the Indenture and subject to the limitations therein set forth, Securities of this series are exchangeable for a like aggregate principal amount of Securities of this series of a different authorized denomination, as requested by the Holder surrendering the same upon surrender of the Security or Securities to be exchanged at the office or agency of the Corporation.

This Security shall be governed by, and construed in accordance with, the laws of the State of New York.

A-9

EXHIBIT 4.2

ABBREVIATIONS

The following abbreviations, when used in the inscription on the face of this instrument, shall be construed as though they were written out in full according to applicable laws or regulations:

TEN COM — as tenants in common	UNIF GIFT MIN ACT -		Custodian
		(Cust)		(Minor)
TEN ENT — as tenants by the entireties
JT TEN — as joint tenants with rights of		under Uniform Gifts to
survivorship and not as tenants in common		Minors Act
		(State)

Additional abbreviations may also be used though not on the above list.

FOR VALUE RECEIVED, the undersigned hereby sell(s) and transfer(s) unto (please insert Social Security or other identifying number of assignee)

PLEASE PRINT OR TYPEWRITE NAME AND ADDRESS, INCLUDING POSTAL ZIP CODE OF ASSIGNEE

the within Security and all rights thereunder, hereby irrevocably constituting and

appointing     agent     to transfer said Security on the books     of the Corporation,     with full power of

substitution in the premises.

Dated:
	NOTICE: The signature to this assignment must
	correspond with the name written upon the face of
	the within instrument in every particular without
	alteration or enlargement, or any change whatever.
	Signature
	Guarantee:

A-10

EXHIBIT 4.2

SIGNATURE GUARANTEE

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Security Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Security Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

A-11

EXHIBIT 4.2

EXHIBIT B CERTIFICATE OF AUTHENTICATION

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture.

Dated:	The Bank of New York Mellon Trust Company,
	N.A., as Trustee
	By:
	Authorized Signatory

B-1

EXHIBIT 4.2

EXHIBIT C CERTIFICATE OF TRANSFER

Re:    DUKE ENERGY CORPORATION 3.95% SENIOR NOTE DUE 2025 (the “Securities”)

This Certificate relates to $principal amount of the Securities held in ^*book-entry or *definitive form by(the “Transferor”).

The Transferor certifies that said beneficial interest in said Security is being resold, pledged or otherwise transferred as follows:*

1¨    to the Corporation; or

2¨    pursuant to an exemption from registration provided by Rule 144 under the Securities Act of 1933, as amended (the “Securities Act”); or

3¨ to a person whom the Transferor reasonably believes is a “qualified institutional buyer” within the meaning of Rule 144A under the Securities Act that purchases for its own account or for the account of a qualified institutional buyer to whom notice is given that the resale, pledge or other transfer is being made in reliance on Rule 144A under the Securities Act; or

4¨    pursuant to an offshore transaction in accordance with Rule 903 or 904 of Regulation S under the Securities Act; or

5¨    pursuant to another applicable exemption from the registration requirements of the Securities Act (and based upon an opinion of counsel acceptable to the Corporation); or

6¨    pursuant to an effective registration statement under the Securities Act.

Unless one of the boxes is checked, the Trustee may refuse to register any of the Securities evidenced by this certificate in the name of any person other than the registered holder thereof; provided, however, that if box (2) is checked, the Corporation or the Trustee, prior to registering any such transfer of the Securities, reserves the right to require the delivery of an opinion of counsel, certifications or other information satisfactory to the Corporation and the Trustee.

Dated:
	NOTICE: The signature to this assignment must
	correspond with the name written upon the face of
	the within instrument in every particular without
	alteration or enlargement, or any change whatever.
	Signature
	Guarantee:

* Fill in blank or check appropriate box, as applicable.

C-1

EXHIBIT 4.2

SIGNATURE GUARANTEE

Signatures must be guaranteed by an “eligible guarantor institution” meeting the requirements of the Security Registrar, which requirements include membership or participation in the Security Transfer Agent Medallion Program (“STAMP”) or such other “signature guarantee program” as may be determined by the Security Registrar in addition to, or in substitution for, STAMP, all in accordance with the Securities Exchange Act of 1934, as amended.

C-2

EXHIBIT 4.2

EXHIBIT D

SCHEDULE I TO GLOBAL SECURITY

The initial amount of the Global Securities evidenced by this certificate is $.

SCHEDULE OF INCREASES OR DECREASES IN GLOBAL SECURITY

The following increases or decreases in this Global Security have been made

	Amount of increase	Amount of decrease	Principal Amount of	Signature of
	in Principal Amount	in Principal Amount	this Global Security	authorized signatory
	of this Global	of this Global	following each	of Trustee or
Date	Security	Security	decrease or increase	Securities Registrar

D-1

EX-12

EXHIBIT 12

COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES - DUKE ENERGY CORPORATION

The ratio of earnings to fixed charges is calculated using the Securities and Exchange Commission guidelines.

	Three Months Ended March 31,		Years Ended December 31,
(in millions)	2018		2017		2016		2015		2014		2013
Earnings as defined for fixed charges calculation
Add:
Pretax income from continuing operations(a)	$	825	$	4,142	$	3,668	$	3,832	$	3,636	$	3,204
Fixed charges	580		2,205		2,170		1,859		1,871		1,886
Distributed income of equity investees	4		16		30		104		136		109
Deduct:
Interest capitalized	1		4		10		18		7		8
Total earnings	$	1,408	$	6,359	$	5,858	$	5,777	$	5,636	$	5,191
Fixed charges:
Interest on debt, including capitalized portions	$	556	$	2,104	$	2,066	$	1,733	$	1,733	$	1,760
Estimate of interest within rental expense	24		101		104		126		138		126
Total fixed charges	$	580	$	2,205	$	2,170	$	1,859	$	1,871	$	1,886
Ratio of earnings to fixed charges	2.4		2.9		2.7		3.1		3.0		2.8

(a)    Excludes amounts attributable to noncontrolling interests and income or loss from equity investees.

EX-31.1.1

EXHIBIT 31.1.1

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Corporation;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chairman, President and

Chief Executive Officer

EX-31.1.2

EXHIBIT 31.1.2

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Carolinas, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

EX-31.1.3

EXHIBIT 31.1.3

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Progress Energy, Inc.;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

EX-31.1.4

EXHIBIT 31.1.4

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Progress, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

EX-31.1.5

EXHIBIT 31.1.5

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Florida, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

EX-31.1.6

EXHIBIT 31.1.6

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Ohio, Inc.;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

EX-31.1.7

EXHIBIT 31.1.7

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Indiana, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

EX-31.1.8

EXHIBIT 31.1.8

CERTIFICATION OF THE CHIEF EXECUTIVE OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Lynn J. Good, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Piedmont Natural Gas Company, Inc.;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

EX-31.2.1

EXHIBIT 31.2.1

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Corporation;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

EX-31.2.2

EXHIBIT 31.2.2

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Carolinas, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

EX-31.2.3

EXHIBIT 31.2.3

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Progress Energy, Inc.;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer 

EX-31.2.4

EXHIBIT 31.2.4

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Progress, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

EX-31.2.5

EXHIBIT 31.2.5

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Florida, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

EX-31.2.6

EXHIBIT 31.2.6

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Ohio, Inc.;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

EX-31.2.7

EXHIBIT 31.2.7

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Duke Energy Indiana, LLC;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a-15(f) and 15d-15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

EX-31.2.8

EXHIBIT 31.2.8

CERTIFICATION OF THE CHIEF FINANCIAL OFFICER

PURSUANT TO SECTION 302 OF THE SARBANES-OXLEY ACT OF 2002

I, Steven K. Young, certify that:

1) I have reviewed this quarterly report on Form 10-Q of Piedmont Natural Gas Company, Inc.;

2) Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3) Based on my knowledge, the financial statements, and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4) The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Acts Rules 13a–15(f) and 15d–15(f)) for the registrant and have:

a) Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

b) Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

c) Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

d) Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting; and

5) The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

a) All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

b) Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 10, 2018

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer 

EX-32.1.1

EXHIBIT 32.1.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Corporation (“Duke Energy”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chairman, President and Chief Executive Officer of Duke Energy, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy.

/s/ LYNN J. GOOD

Lynn J. Good

Chairman, President and

Chief Executive Officer

May 10, 2018

EX-32.1.2

EXHIBIT 32.1.2

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Carolinas, LLC (“Duke Energy Carolinas”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chief Executive Officer of Duke Energy Carolinas, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Carolinas.

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

May 10, 2018

EX-32.1.3

EXHIBIT 32.1.3

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Progress Energy, Inc. (“Progress Energy”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chief Executive Officer of Progress Energy, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Progress Energy.

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

May 10, 2018

EX-32.1.4

EXHIBIT 32.1.4

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Progress, LLC (“Duke Energy Progress”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chief Executive Officer of Duke Energy Progress, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Progress.

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

May 10, 2018

EX-32.1.5

EXHIBIT 32.1.5

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Florida, LLC (“Duke Energy Florida”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chief Executive Officer of Duke Energy Florida, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Florida.

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

May 10, 2018

EX-32.1.6

EXHIBIT 32.1.6

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Ohio, Inc. (“Duke Energy Ohio”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chief Executive Officer of Duke Energy Ohio, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Ohio.

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

May 10, 2018

EX-32.1.7

EXHIBIT 32.1.7

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Indiana, LLC (“Duke Energy Indiana”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chief Executive Officer of Duke Energy Indiana, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Indiana.

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

May 10, 2018

EX-32.1.8

EXHIBIT 32.1.8

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Piedmont Natural Gas Company, Inc. (“Piedmont”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Lynn J. Good, Chief Executive Officer of Piedmont, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Piedmont.

/s/ LYNN J. GOOD

Lynn J. Good

Chief Executive Officer

May 10, 2018

EX-32.2.1

EXHIBIT 32.2.1

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Corporation (“Duke Energy”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Duke Energy, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

EX-32.2.2

EXHIBIT 32.2.2

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Carolinas, LLC (“Duke Energy Carolinas”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Duke Energy Carolinas, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Carolinas.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

EX-32.2.3

EXHIBIT 32.2.3

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Progress Energy, Inc. (“Progress Energy”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Progress Energy, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Progress Energy.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

EX-32.2.4

EXHIBIT 32.2.4

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Progress, LLC (“Duke Energy Progress”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Duke Energy Progress, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Progress.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

EX-32.2.5

EXHIBIT 32.2.5

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Florida, LLC (“Duke Energy Florida”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Duke Energy Florida, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Florida.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

EX-32.2.6

EXHIBIT 32.2.6

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Ohio, Inc. (“Duke Energy Ohio”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Duke Energy Ohio, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Ohio.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

EX-32.2.7

EXHIBIT 32.2.7

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Duke Energy Indiana, LLC (“Duke Energy Indiana”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Duke Energy Indiana, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Duke Energy Indiana.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

EX-32.2.8

EXHIBIT 32.2.8

CERTIFICATION PURSUANT TO

18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report of Piedmont Natural Gas Company, Inc. (“Piedmont”) on Form 10-Q for the period ending March 31, 2018, as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Steven K. Young, Executive Vice President and Chief Financial Officer of Piedmont, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:

(1) The Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of Piedmont.

/s/ STEVEN K. YOUNG

Steven K. Young

Executive Vice President and Chief Financial Officer

May 10, 2018

XML

Document and Entity Information	3 Months Ended
	Mar. 31, 2018 shares
Document Information [Line Items]
Entity Registrant Name	Duke Energy Corporation
Entity Central Index Key	0001326160
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-Q
Document Period End Date	Mar. 31, 2018
Document Fiscal Year Focus	2018
Document Fiscal Period Focus	Q1
Amendment Flag	false
Entity Common Stock, Shares Outstanding	701,007,267
Trading Symbol	DUK
Duke Energy Carolinas [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Carolinas, LLC
Entity Central Index Key	0000030371
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Progress Energy [Member]
Document Information [Line Items]
Entity Registrant Name	Progress Energy, Inc
Entity Central Index Key	0001094093
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Progress [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Progress, LLC
Entity Central Index Key	0000017797
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Florida [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Florida, LLC
Entity Central Index Key	0000037637
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Ohio [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Ohio, Inc.
Entity Central Index Key	0000020290
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Duke Energy Indiana [Member]
Document Information [Line Items]
Entity Registrant Name	Duke Energy Indiana, LLC
Entity Central Index Key	0000081020
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer
Piedmont Natural Gas [Member]
Document Information [Line Items]
Entity Registrant Name	Piedmont Natural Gas Company, Inc.
Entity Central Index Key	0000078460
Current Fiscal Year End Date	--12-31
Entity Filer Category	Non-accelerated Filer

XML

Condensed Consolidated Statements of Operations and Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Operating Revenues
Regulated electric	$ 5,284	$ 4,913
Regulated natural gas	700	646
Nonregulated electric and other	151	170
Total operating revenues	6,135	5,729
Operating Expenses
Fuel used in electric generation and purchased power	1,676	1,449
Cost of natural gas	313	258
Operation, maintenance and other	1,464	1,468
Depreciation and amortization	967	859
Property and other taxes	316	304
Impairment charges	43
Total operating expenses	4,779	4,338
(Loss) Gains on Sales of Other Assets and Other, net	(100)	11
Operating Income	1,256	1,402
Other Income and Expenses
Equity in (losses) earnings of unconsolidated affiliates	(24)	29
Other income and expenses, net	86	121
Total other income and expenses	62	150
Interest Expense	515	491
Income Before Income Taxes	803	1,061
Income Tax Expense	181	344
Net income	622	717
Less: Net Income Attributable to Noncontrolling Interests	2	1
Net Income Attributable to Parent	620	716
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments	1	1
Net unrealized gain on cash flow hedges	12	2
Reclassification into earnings from cash flow hedges	1	1
Unrealized gains on available-for-sale securities	(3)	4
Other Comprehensive Income, net of tax	11	8
Comprehensive Income	633	725
Less: Comprehensive Income Attributable to Noncontrolling Interests	2	1
Comprehensive Income Attributable to Parent	$ 631	$ 724
Net income attributable to Duke Energy Corporation common stockholders
Basic (usd per share)	$ 0.88	$ 1.02
Diluted (usd per share)	$ 0.88	$ 1.02
Weighted average shares outstanding
Basic (shares)	701	700
Diluted (shares)	701	700
Duke Energy Carolinas [Member]
Operating Revenues
Total operating revenues	$ 1,763	$ 1,716
Operating Expenses
Fuel used in electric generation and purchased power	473	428
Operation, maintenance and other	451	495
Depreciation and amortization	272	254
Property and other taxes	72	68
Impairment charges	13
Total operating expenses	1,281	1,245
Operating Income	482	471
Other Income and Expenses
Total other income and expenses	39	50
Interest Expense	107	103
Income Before Income Taxes	414	418
Income Tax Expense	91	148
Net Income Attributable to Parent	323	270
Other Comprehensive Income (Loss), net of tax
Reclassification into earnings from cash flow hedges	1
Other Comprehensive Income, net of tax	1
Comprehensive Income Attributable to Parent	324	270
Progress Energy [Member]
Operating Revenues
Total operating revenues	2,576	2,179
Operating Expenses
Fuel used in electric generation and purchased power	976	726
Operation, maintenance and other	623	560
Depreciation and amortization	384	313
Property and other taxes	123	117
Impairment charges	29
Total operating expenses	2,135	1,716
(Loss) Gains on Sales of Other Assets and Other, net	6	8
Operating Income	447	471
Other Income and Expenses
Total other income and expenses	35	40
Interest Expense	209	206
Income Before Income Taxes	273	305
Income Tax Expense	36	104
Net income	237	201
Less: Net Income Attributable to Noncontrolling Interests	2	2
Net Income Attributable to Parent	235	199
Other Comprehensive Income (Loss), net of tax
Pension and OPEB adjustments		1
Net unrealized gain on cash flow hedges	2
Reclassification into earnings from cash flow hedges		1
Unrealized gains on available-for-sale securities		1
Other Comprehensive Income, net of tax	2	3
Comprehensive Income	239	204
Less: Comprehensive Income Attributable to Noncontrolling Interests	2	2
Comprehensive Income Attributable to Parent	237	202
Duke Energy Progress [Member]
Operating Revenues
Total operating revenues	1,460	1,219
Operating Expenses
Fuel used in electric generation and purchased power	509	364
Operation, maintenance and other	381	362
Depreciation and amortization	235	181
Property and other taxes	35	40
Impairment charges	32
Total operating expenses	1,192	947
(Loss) Gains on Sales of Other Assets and Other, net	1	2
Operating Income	269	274
Other Income and Expenses
Total other income and expenses	18	31
Interest Expense	81	82
Income Before Income Taxes	206	223
Income Tax Expense	29	76
Net Income Attributable to Parent	177	147
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Parent	177	147
Duke Energy Florida [Member]
Operating Revenues
Total operating revenues	1,115	959
Operating Expenses
Fuel used in electric generation and purchased power	467	362
Operation, maintenance and other	237	195
Depreciation and amortization	150	132
Property and other taxes	88	77
Impairment charges		1
Total operating expenses	942	767
Operating Income	173	192
Other Income and Expenses
Total other income and expenses	21	20
Interest Expense	71	70
Income Before Income Taxes	123	142
Income Tax Expense	20	52
Net Income Attributable to Parent	103	90
Other Comprehensive Income (Loss), net of tax
Unrealized gains on available-for-sale securities		1
Other Comprehensive Income, net of tax		1
Comprehensive Income Attributable to Parent	103	91
Duke Energy Ohio [Member]
Operating Revenues
Regulated electric	336	337
Regulated natural gas	174	170
Nonregulated electric and other	14	11
Total operating revenues	524	518
Operating Expenses
Fuel used in electric generation and purchased power	92	97
Fuel used in electric generation and purchased power – nonregulated	15	15
Cost of natural gas	54	54
Operation, maintenance and other	131	131
Depreciation and amortization	70	67
Property and other taxes	77	72
Total operating expenses	439	436
(Loss) Gains on Sales of Other Assets and Other, net	(106)
Operating Income	(21)	82
Other Income and Expenses
Total other income and expenses	6	5
Interest Expense	22	22
Income Before Income Taxes	(37)	65
Income Tax Expense	(12)	23
Net Income Attributable to Parent	(25)	42
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Parent	(25)	42
Duke Energy Indiana [Member]
Operating Revenues
Total operating revenues	731	758
Operating Expenses
Fuel used in electric generation and purchased power	232	251
Operation, maintenance and other	181	176
Depreciation and amortization	130	125
Property and other taxes	20	22
Total operating expenses	563	574
Operating Income	168	184
Other Income and Expenses
Total other income and expenses	7	10
Interest Expense	40	44
Income Before Income Taxes	135	150
Income Tax Expense	35	59
Net Income Attributable to Parent	100	91
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Parent	100	91
Piedmont Natural Gas [Member]
Operating Revenues
Total operating revenues	553	500
Operating Expenses
Cost of natural gas	259	205
Operation, maintenance and other	82	77
Depreciation and amortization	39	35
Property and other taxes	12	13
Total operating expenses	392	330
Operating Income	161	170
Other Income and Expenses
Equity in (losses) earnings of unconsolidated affiliates	2	3
Other income and expenses, net	3
Total other income and expenses	5	3
Interest Expense	21	20
Income Before Income Taxes	145	153
Income Tax Expense	35	58
Net Income Attributable to Parent	110	95
Other Comprehensive Income (Loss), net of tax
Comprehensive Income Attributable to Parent	$ 110	$ 95

XML

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Comprehensive Income (Loss), Net of Tax, Including Portion Attributable to Noncontrolling Interest [Abstract]
Net income	$ 622	$ 717
Other Comprehensive Income, net of tax
Pension and OPEB adjustments	1	1
Net unrealized gains on cash flow hedges	12	2
Reclassification into earnings from cash flow hedges	1	1
Unrealized (losses) gains on available-for-sale securities	(3)	4
Other Comprehensive Income, net of tax	11	8
Comprehensive Income	633	725
Less: Comprehensive Income Attributable to Noncontrolling Interests	2	1
Comprehensive Income Attributable to Parent	$ 631	$ 724

XML

Condensed Consolidated Balance Sheets - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Current Assets
Cash and cash equivalents	$ 421	$ 358
Receivables (net of allowance for doubtful accounts)	759	779
Receivables of VIEs (net of allowance for doubtful accounts)	1,984	1,995
Inventory	3,149	3,250
Regulatory assets	1,544	1,437
Other	422	634
Total current assets	8,279	8,453
Property, Plant and Equipment
Cost	129,281	127,507
Accumulated depreciation and amortization	(42,307)	(41,537)
Generation facilities to be retired, net	399	421
Net property, plant and equipment	87,373	86,391
Other Noncurrent Assets
Goodwill	19,396	19,396
Regulatory assets	12,218	12,442
Nuclear decommissioning trust funds	7,024	7,097
Investments in equity method unconsolidated affiliates	1,189	1,175
Other	3,062	2,960
Total other noncurrent assets	42,889	43,070
Total Assets	138,541	137,914
Current Liabilities
Accounts payable	2,391	3,043
Notes payable and commercial paper	2,969	2,163
Taxes accrued	422	551
Interest accrued	542	525
Current maturities of long-term debt	3,951	3,244
Asset retirement obligations	676	689
Regulatory liabilities	505	402
Other	1,542	1,865
Total current liabilities	12,998	12,482
Long-Term Debt	49,030	49,035
Other Noncurrent Liabilities
Deferred income taxes	6,855	6,621
Asset retirement obligations	9,484	9,486
Regulatory liabilities	15,283	15,330
Accrued pension and other post-retirement benefit costs	1,018	1,103
Investment tax credits	537	539
Other	1,538	1,581
Total other noncurrent liabilities	34,715	34,660
Commitments and Contingencies
Equity
Common stock	1	1
Additional paid-in capital	38,839	38,792
Retained earnings	3,021	3,013
Accumulated other comprehensive loss	(69)	(67)
Total Parent stockholders' equity	41,792	41,739
Noncontrolling interests	6	(2)
Total equity	41,798	41,737
Total Liabilities and Equity	138,541	137,914
Duke Energy Carolinas [Member]
Current Assets
Cash and cash equivalents	3	16
Receivables (net of allowance for doubtful accounts)	194	200
Receivables of VIEs (net of allowance for doubtful accounts)	634	640
Receivables from affiliated companies	106	95
Inventory	980	971
Regulatory assets	331	299
Other	42	19
Total current assets	2,290	2,240
Property, Plant and Equipment
Cost	43,562	42,939
Accumulated depreciation and amortization	(15,404)	(15,063)
Net property, plant and equipment	28,158	27,876
Other Noncurrent Assets
Regulatory assets	2,825	2,853
Nuclear decommissioning trust funds	3,734	3,772
Other	1,023	979
Total other noncurrent assets	7,582	7,604
Total Assets	38,030	37,720
Current Liabilities
Accounts payable	726	842
Accounts payable to affiliated companies	259	209
Notes payable to affiliated companies	45	104
Taxes accrued	84	234
Interest accrued	144	108
Current maturities of long-term debt	805	1,205
Asset retirement obligations	281	337
Regulatory liabilities	116	126
Other	369	486
Total current liabilities	2,829	3,651
Long-Term Debt	9,589	8,598
Long-Term Debt Payable to Affiliated Companies	300	300
Other Noncurrent Liabilities
Deferred income taxes	3,493	3,413
Asset retirement obligations	3,318	3,273
Regulatory liabilities	6,208	6,231
Accrued pension and other post-retirement benefit costs	95	95
Investment tax credits	231	232
Other	532	566
Total other noncurrent liabilities	13,877	13,810
Commitments and Contingencies
Equity
Member's equity	11,441	11,368
Accumulated other comprehensive loss	(6)	(7)
Total member's equity	11,435	11,361
Total Liabilities and Equity	38,030	37,720
Progress Energy [Member]
Current Assets
Cash and cash equivalents	20	40
Receivables (net of allowance for doubtful accounts)	122	123
Receivables of VIEs (net of allowance for doubtful accounts)	815	780
Receivables from affiliated companies	2	31
Notes receivable from affiliated companies	113	240
Inventory	1,537	1,592
Regulatory assets	869	741
Other	259	334
Total current assets	3,737	3,881
Property, Plant and Equipment
Cost	47,915	47,323
Accumulated depreciation and amortization	(16,060)	(15,857)
Generation facilities to be retired, net	399	421
Net property, plant and equipment	32,254	31,887
Other Noncurrent Assets
Goodwill	3,655	3,655
Regulatory assets	5,872	6,010
Nuclear decommissioning trust funds	3,290	3,324
Other	990	931
Total other noncurrent assets	13,807	13,920
Total Assets	49,798	49,688
Current Liabilities
Accounts payable	760	1,006
Accounts payable to affiliated companies	284	251
Notes payable to affiliated companies	982	805
Taxes accrued	109	101
Interest accrued	213	212
Current maturities of long-term debt	1,820	771
Asset retirement obligations	326	295
Regulatory liabilities	272	213
Other	637	729
Total current liabilities	5,403	4,383
Long-Term Debt	15,787	16,916
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	3,603	3,502
Asset retirement obligations	5,091	5,119
Regulatory liabilities	5,227	5,306
Accrued pension and other post-retirement benefit costs	527	545
Other	307	302
Total other noncurrent liabilities	14,755	14,774
Commitments and Contingencies
Equity
Additional paid-in capital	9,142	9,143
Retained earnings	4,591	4,350
Accumulated other comprehensive loss	(29)	(25)
Total Parent stockholders' equity	13,704	13,468
Noncontrolling interests	(1)	(3)
Total equity	13,703	13,465
Total Liabilities and Equity	49,798	49,688
Duke Energy Progress [Member]
Current Assets
Cash and cash equivalents	8	20
Receivables (net of allowance for doubtful accounts)	50	56
Receivables of VIEs (net of allowance for doubtful accounts)	497	459
Receivables from affiliated companies	5	3
Inventory	1,002	1,017
Regulatory assets	476	352
Other	55	97
Total current assets	2,093	2,004
Property, Plant and Equipment
Cost	29,866	29,583
Accumulated depreciation and amortization	(11,012)	(10,903)
Generation facilities to be retired, net	399	421
Net property, plant and equipment	19,253	19,101
Other Noncurrent Assets
Regulatory assets	3,480	3,507
Nuclear decommissioning trust funds	2,568	2,588
Other	641	599
Total other noncurrent assets	6,689	6,694
Total Assets	28,035	27,799
Current Liabilities
Accounts payable	342	402
Accounts payable to affiliated companies	208	179
Notes payable to affiliated companies	354	240
Taxes accrued	36	64
Interest accrued	86	102
Current maturities of long-term debt	603	3
Asset retirement obligations	323	295
Regulatory liabilities	184	139
Other	324	376
Total current liabilities	2,460	1,800
Long-Term Debt	6,604	7,204
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	1,932	1,883
Asset retirement obligations	4,356	4,378
Regulatory liabilities	3,973	3,999
Accrued pension and other post-retirement benefit costs	246	248
Investment tax credits	142	143
Other	46	45
Total other noncurrent liabilities	10,695	10,696
Commitments and Contingencies
Equity
Total member's equity	8,126	7,949
Total Liabilities and Equity	28,035	27,799
Duke Energy Florida [Member]
Current Assets
Cash and cash equivalents	6	13
Receivables (net of allowance for doubtful accounts)	71	65
Receivables of VIEs (net of allowance for doubtful accounts)	318	321
Receivables from affiliated companies	1	2
Notes receivable from affiliated companies	153	313
Inventory	535	574
Regulatory assets	393	389
Other	40	86
Total current assets	1,517	1,763
Property, Plant and Equipment
Cost	18,040	17,730
Accumulated depreciation and amortization	(5,042)	(4,947)
Net property, plant and equipment	12,998	12,783
Other Noncurrent Assets
Regulatory assets	2,391	2,503
Nuclear decommissioning trust funds	722	736
Other	301	284
Total other noncurrent assets	3,414	3,523
Total Assets	17,929	18,069
Current Liabilities
Accounts payable	416	602
Accounts payable to affiliated companies	82	74
Taxes accrued	72	34
Interest accrued	74	56
Current maturities of long-term debt	768	768
Asset retirement obligations	3	0
Regulatory liabilities	88	74
Other	299	334
Total current liabilities	1,802	1,942
Long-Term Debt	6,247	6,327
Other Noncurrent Liabilities
Deferred income taxes	1,812	1,761
Asset retirement obligations	735	742
Regulatory liabilities	1,254	1,307
Accrued pension and other post-retirement benefit costs	248	264
Other	110	108
Total other noncurrent liabilities	4,159	4,182
Commitments and Contingencies
Equity
Member's equity	5,723	5,614
Accumulated other comprehensive loss	(2)	4
Total member's equity	5,721	5,618
Total Liabilities and Equity	17,929	18,069
Duke Energy Ohio [Member]
Current Assets
Cash and cash equivalents	12	12
Receivables (net of allowance for doubtful accounts)	69	68
Receivables from affiliated companies	77	133
Notes receivable from affiliated companies		14
Inventory	108	133
Regulatory assets	43	49
Other	24	39
Total current assets	333	448
Property, Plant and Equipment
Cost	8,892	8,732
Accumulated depreciation and amortization	(2,729)	(2,691)
Net property, plant and equipment	6,163	6,041
Other Noncurrent Assets
Goodwill	920	920
Regulatory assets	432	445
Other	48	21
Total other noncurrent assets	1,400	1,386
Total Assets	7,896	7,875
Current Liabilities
Accounts payable	269	313
Accounts payable to affiliated companies	72	62
Notes payable to affiliated companies	130	29
Taxes accrued	145	190
Interest accrued	33	21
Current maturities of long-term debt	3	3
Asset retirement obligations	4	3
Regulatory liabilities	53	36
Other	66	71
Total current liabilities	775	728
Long-Term Debt	2,039	2,039
Long-Term Debt Payable to Affiliated Companies	25	25
Other Noncurrent Liabilities
Deferred income taxes	766	781
Asset retirement obligations	79	81
Regulatory liabilities	888	891
Accrued pension and other post-retirement benefit costs	81	59
Other	105	108
Total other noncurrent liabilities	1,919	1,920
Commitments and Contingencies
Equity
Common stock	762	762
Additional paid-in capital	2,670	2,670
Retained earnings	(294)	(269)
Total Parent stockholders' equity	3,138	3,163
Total Liabilities and Equity	7,896	7,875
Duke Energy Indiana [Member]
Current Assets
Cash and cash equivalents	15	9
Receivables (net of allowance for doubtful accounts)	56	57
Receivables from affiliated companies	99	125
Inventory	453	450
Regulatory assets	170	165
Other	30	30
Total current assets	823	836
Property, Plant and Equipment
Cost	15,104	14,948
Accumulated depreciation and amortization	(4,759)	(4,662)
Net property, plant and equipment	10,345	10,286
Other Noncurrent Assets
Regulatory assets	976	978
Other	234	189
Total other noncurrent assets	1,210	1,167
Total Assets	12,378	12,289
Current Liabilities
Accounts payable	157	196
Accounts payable to affiliated companies	73	78
Notes payable to affiliated companies	149	161
Taxes accrued	94	95
Interest accrued	52	57
Current maturities of long-term debt	62	3
Asset retirement obligations	65	54
Regulatory liabilities	20	24
Other	83	104
Total current liabilities	755	772
Long-Term Debt	3,570	3,630
Long-Term Debt Payable to Affiliated Companies	150	150
Other Noncurrent Liabilities
Deferred income taxes	941	925
Asset retirement obligations	713	727
Regulatory liabilities	1,743	1,723
Accrued pension and other post-retirement benefit costs	110	76
Investment tax credits	147	147
Other	28	18
Total other noncurrent liabilities	3,682	3,616
Commitments and Contingencies
Equity
Total member's equity	4,221	4,121
Total Liabilities and Equity	12,378	12,289
Piedmont Natural Gas [Member]
Current Assets
Cash and cash equivalents	12	19
Receivables (net of allowance for doubtful accounts)	251	275
Receivables from affiliated companies	7	7
Inventory	29	66
Regulatory assets	48	95
Other	21	52
Total current assets	368	514
Property, Plant and Equipment
Cost	6,861	6,725
Accumulated depreciation and amortization	(1,500)	(1,479)
Net property, plant and equipment	5,361	5,246
Other Noncurrent Assets
Goodwill	49	49
Regulatory assets	274	283
Investments in equity method unconsolidated affiliates	62	61
Other	66	65
Total other noncurrent assets	451	458
Total Assets	6,180	6,218
Current Liabilities
Accounts payable	128	125
Accounts payable to affiliated companies	32	13
Notes payable to affiliated companies	107	364
Taxes accrued	65	19
Interest accrued	24	31
Current maturities of long-term debt	250	250
Regulatory liabilities	45	3
Other	55	69
Total current liabilities	706	874
Long-Term Debt	1,787	1,787
Other Noncurrent Liabilities
Deferred income taxes	558	564
Asset retirement obligations	15	15
Regulatory liabilities	1,179	1,141
Accrued pension and other post-retirement benefit costs	4	5
Other	159	170
Total other noncurrent liabilities	1,915	1,895
Commitments and Contingencies
Equity
Common stock	860	860
Retained earnings	912	802
Total Parent stockholders' equity	1,772	1,662
Total Liabilities and Equity	$ 6,180	$ 6,218

XML

Condensed Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Allowance for doubtful accounts - receivables	$ 17	$ 14
Regulatory assets, current	1,544	1,437
Other, current assets	422	634
Regulatory assets, noncurrent	12,218	12,442
Current maturities of long-term debt	3,951	3,244
Long-Term Debt	$ 49,030	$ 49,035
Common stock, par value	$ 0.001	$ 0.001
Common stock, shares authorized	2,000,000,000	2,000,000,000
Common stock, shares outstanding	701,000,000	700,000,000
Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	$ 57	$ 54
Regulatory assets, current	51	51
Regulatory assets, noncurrent	1,082	1,091
Current maturities of long-term debt	225	225
Long-Term Debt	4,275	4,306
Duke Energy Carolinas [Member]
Allowance for doubtful accounts - receivables	2	2
Regulatory assets, current	331	299
Other, current assets	42	19
Regulatory assets, noncurrent	2,825	2,853
Current maturities of long-term debt	805	1,205
Long-Term Debt	9,589	8,598
Duke Energy Carolinas [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	7	7
Progress Energy [Member]
Allowance for doubtful accounts - receivables	4	4
Regulatory assets, current	869	741
Other, current assets	259	334
Regulatory assets, noncurrent	5,872	6,010
Current maturities of long-term debt	1,820	771
Long-Term Debt	$ 15,787	$ 16,916
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100
Progress Energy [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	$ 7	$ 7
Regulatory assets, current	51	51
Regulatory assets, noncurrent	1,082	1,091
Current maturities of long-term debt	53	53
Long-Term Debt	1,660	1,689
Duke Energy Progress [Member]
Allowance for doubtful accounts - receivables	2	1
Regulatory assets, current	476	352
Other, current assets	55	97
Regulatory assets, noncurrent	3,480	3,507
Current maturities of long-term debt	603	3
Long-Term Debt	6,604	7,204
Duke Energy Progress [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	5	5
Duke Energy Florida [Member]
Allowance for doubtful accounts - receivables	3	3
Regulatory assets, current	393	389
Other, current assets	40	86
Regulatory assets, noncurrent	2,391	2,503
Current maturities of long-term debt	768	768
Long-Term Debt	6,247	6,327
Duke Energy Florida [Member] | Variable Interest Entity [Member]
Allowance for doubtful accounts - receivables of VIEs	2	2
Regulatory assets, current	51	51
Other, current assets	13	40
Regulatory assets, noncurrent	1,082	1,091
Current maturities of long-term debt	53	53
Long-Term Debt	1,361	1,389
Duke Energy Ohio [Member]
Allowance for doubtful accounts - receivables	3	3
Regulatory assets, current	43	49
Other, current assets	24	39
Regulatory assets, noncurrent	432	445
Current maturities of long-term debt	3	3
Long-Term Debt	$ 2,039	$ 2,039
Common stock, par value	$ 8.50	$ 8.50
Common stock, shares authorized	120,000,000	120,000,000
Common stock, shares outstanding	90,000,000	90,000,000
Duke Energy Indiana [Member]
Allowance for doubtful accounts - receivables	$ 2	$ 2
Regulatory assets, current	170	165
Other, current assets	30	30
Regulatory assets, noncurrent	976	978
Current maturities of long-term debt	62	3
Long-Term Debt	3,570	3,630
Piedmont Natural Gas [Member]
Allowance for doubtful accounts - receivables	4	2
Regulatory assets, current	48	95
Other, current assets	21	52
Regulatory assets, noncurrent	274	283
Current maturities of long-term debt	250	250
Long-Term Debt	$ 1,787	$ 1,787
Common stock, shares authorized	100	100
Common stock, shares outstanding	100	100

XML

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 622	$ 717
Net income (attributable to parent)	620	716
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	1,089	991
Equity component of AFUDC	(55)	(62)
Losses (gains) on sales of other assets	100	(11)
Impairment charges	43
Deferred income taxes	199	342
Equity in losses (earnings) of unconsolidated affiliates	24	(29)
Accrued pension and other post-retirement benefit costs	15	6
Contributions to qualified pension plans	(141)
Payments for asset retirement obligations	(122)	(134)
Payment for disposal of other assets	(105)
Other rate case adjustments	37
Provision for rate refunds	158
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	4	(38)
Receivables	64	343
Inventory	101	155
Other current assets	27	(22)
Increase (decrease) in
Accounts payable	(327)	(463)
Taxes accrued	(107)	(28)
Other current liabilities	(171)	(478)
Other assets	(59)	(45)
Other liabilities	(5)	2
Net cash provided by operating activities	1,391	1,246
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(2,087)	(2,160)
Cost of removal, net of salvage	(81)	(39)
Contributions to equity method investments	(74)	(175)
Purchases of debt and equity securities	(958)	(1,386)
Proceeds from sales and maturities of debt and equity securities	930	1,405
Other	6	(6)
Net cash used in investing activities	(2,264)	(2,361)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	1,240	1,563
Proceeds from the issuance of common stock	21
Payments for the redemption of long-term debt	(487)	(408)
Proceeds from issuance of short-term debt with original maturities greater than 90 days	135	25
Payments for the redemption of short-term debt with original maturities greater than 90 days	(50)	(7)
Notes payable and commercial paper	706	1,045
Dividends paid	(599)	(600)
Other	(19)	(22)
Net cash provided by financing activities	947	1,596
Net increase in cash, cash equivalents and restricted cash	74	481
Cash, cash equivalents and restricted cash at beginning of period	505	541
Cash, cash equivalents and restricted cash at end of period	579	1,022
Cash and cash equivalents at beginning of period	358
Cash and cash equivalents at end of period	421
Significant non-cash transactions:
Accrued capital expenditures	799	575
Non-cash dividends	26
Duke Energy Carolinas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	323	270
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	347	339
Equity component of AFUDC	(21)	(30)
Impairment charges	13
Deferred income taxes	80	162
Accrued pension and other post-retirement benefit costs	1
Contributions to qualified pension plans	(46)
Payments for asset retirement obligations	(55)	(65)
Provision for rate refunds	61
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		3
Receivables	19	66
Receivable from affiliated companies	(11)	54
Inventory	(9)	4
Other current assets	(144)	(26)
Increase (decrease) in
Accounts payable	(76)	(131)
Accounts payable to affiliated companies	50	3
Taxes accrued	(129)	(53)
Other current liabilities	(23)	(125)
Other assets	12	(3)
Other liabilities	(43)	(2)
Net cash provided by operating activities	349	466
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(621)	(563)
Cost of removal, net of salvage	(17)	(16)
Purchases of debt and equity securities	(494)	(722)
Proceeds from sales and maturities of debt and equity securities	494	722
Notes receivable from affiliated companies		66
Other	(4)	(4)
Net cash used in investing activities	(642)	(517)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt	991
Payments for the redemption of long-term debt	(401)	(113)
Notes payable to affiliated companies	(59)	337
Distributions to parent	(250)	(175)
Other	(1)	(1)
Net cash provided by financing activities	280	48
Net increase (decrease) in cash and cash equivalents	(13)	(3)
Cash and cash equivalents at beginning of period	16	14
Cash and cash equivalents at end of period	3	11
Significant non-cash transactions:
Accrued capital expenditures	267	164
Progress Energy [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	237	201
Net income (attributable to parent)	235	199
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	439	365
Equity component of AFUDC	(26)	(24)
Losses (gains) on sales of other assets	(6)	(9)
Impairment charges	29
Deferred income taxes	71	220
Accrued pension and other post-retirement benefit costs	6	(3)
Contributions to qualified pension plans	(45)
Payments for asset retirement obligations	(55)	(60)
Other rate case adjustments	37
Provision for rate refunds	33
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	4	(2)
Receivables	(33)	115
Receivable from affiliated companies	29	100
Inventory	55	65
Other current assets	(60)	(212)
Increase (decrease) in
Accounts payable	(53)	(228)
Accounts payable to affiliated companies	33	(32)
Taxes accrued	8	12
Other current liabilities	(82)	(121)
Other assets	(86)	(58)
Other liabilities	(8)	(14)
Net cash provided by operating activities	527	315
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(762)	(1,011)
Cost of removal, net of salvage	(41)
Purchases of debt and equity securities	(406)	(629)
Proceeds from sales and maturities of debt and equity securities	411	635
Notes receivable from affiliated companies	127	(104)
Other	1	5
Net cash used in investing activities	(670)	(1,104)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		892
Payments for the redemption of long-term debt	(80)	(288)
Notes payable to affiliated companies	177	137
Other	(2)	(4)
Net cash provided by financing activities	95	737
Net increase in cash, cash equivalents and restricted cash	(48)	(52)
Cash, cash equivalents and restricted cash at beginning of period	87	110
Cash, cash equivalents and restricted cash at end of period	39	58
Cash and cash equivalents at beginning of period	40
Cash and cash equivalents at end of period	20
Significant non-cash transactions:
Accrued capital expenditures	316	219
Duke Energy Progress [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	177	147
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	284	228
Equity component of AFUDC	(14)	(13)
Losses (gains) on sales of other assets	(1)	(3)
Impairment charges	32
Deferred income taxes	42	120
Accrued pension and other post-retirement benefit costs	4	(5)
Contributions to qualified pension plans	(25)
Payments for asset retirement obligations	(44)	(47)
Other rate case adjustments	37
Provision for rate refunds	33
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2	(2)
Receivables	(31)	65
Receivable from affiliated companies	(2)	(1)
Inventory	15	23
Other current assets	(88)	(60)
Increase (decrease) in
Accounts payable	(39)	(192)
Accounts payable to affiliated companies	29	17
Taxes accrued	(28)	(68)
Other current liabilities	(64)	(81)
Other assets	18	(44)
Other liabilities	(5)	(10)
Net cash provided by operating activities	332	74
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(424)	(474)
Cost of removal, net of salvage	(31)	(9)
Purchases of debt and equity securities	(284)	(476)
Proceeds from sales and maturities of debt and equity securities	281	470
Notes receivable from affiliated companies		165
Other	1
Net cash used in investing activities	(457)	(324)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt		(250)
Notes payable to affiliated companies	114	502
Other	(1)	(2)
Net cash provided by financing activities	113	250
Net increase (decrease) in cash and cash equivalents	(12)
Cash and cash equivalents at beginning of period	20	11
Cash and cash equivalents at end of period	8	11
Significant non-cash transactions:
Accrued capital expenditures	137	66
Duke Energy Florida [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	103	90
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	152	134
Equity component of AFUDC	(12)	(11)
Impairment charges		1
Deferred income taxes	29	100
Accrued pension and other post-retirement benefit costs	1	1
Contributions to qualified pension plans	(20)
Payments for asset retirement obligations	(11)	(14)
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions	2
Receivables	(2)	51
Receivable from affiliated companies		(1)
Inventory	39	42
Other current assets	42	(72)
Increase (decrease) in
Accounts payable	(13)	(35)
Accounts payable to affiliated companies	8	(48)
Taxes accrued	38	29
Other current liabilities	(17)	(47)
Other assets	(107)	(13)
Other liabilities	(5)	(5)
Net cash provided by operating activities	227	202
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(338)	(538)
Cost of removal, net of salvage	(10)	9
Purchases of debt and equity securities	(122)	(153)
Proceeds from sales and maturities of debt and equity securities	129	165
Notes receivable from affiliated companies	160	(293)
Other		4
Net cash used in investing activities	(181)	(806)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		892
Payments for the redemption of long-term debt	(80)	(38)
Notes payable to affiliated companies		(297)
Other		(1)
Net cash provided by financing activities	(80)	556
Net increase in cash, cash equivalents and restricted cash	(34)	(48)
Cash, cash equivalents and restricted cash at beginning of period	53	69
Cash, cash equivalents and restricted cash at end of period	19	21
Cash and cash equivalents at beginning of period	13
Cash and cash equivalents at end of period	6
Significant non-cash transactions:
Accrued capital expenditures	179	153
Duke Energy Ohio [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	(25)	42
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	71	68
Equity component of AFUDC	(4)	(2)
Losses (gains) on sales of other assets	106
Deferred income taxes	(15)	30
Accrued pension and other post-retirement benefit costs	1	1
Payments for asset retirement obligations	(1)	(2)
Provision for rate refunds	16
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		1
Receivables	(1)	7
Receivable from affiliated companies	56	41
Inventory	25	19
Other current assets	19	9
Increase (decrease) in
Accounts payable	(27)	(10)
Accounts payable to affiliated companies	(95)	1
Taxes accrued	(45)	(52)
Other current liabilities	20	9
Other assets		(6)
Other liabilities	(13)	(3)
Net cash provided by operating activities	88	153
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(188)	(143)
Cost of removal, net of salvage	(14)	(8)
Notes receivable from affiliated companies	14	(85)
Net cash used in investing activities	(188)	(236)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from the issuance of long-term debt		93
Payments for the redemption of long-term debt		(1)
Notes payable to affiliated companies	101	(8)
Other	(1)	(1)
Net cash provided by financing activities	100	83
Cash and cash equivalents at beginning of period	12	13
Cash and cash equivalents at end of period	12	13
Significant non-cash transactions:
Accrued capital expenditures	64	57
Duke Energy Indiana [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	100	91
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	131	126
Equity component of AFUDC	(4)	(6)
Deferred income taxes	17	37
Accrued pension and other post-retirement benefit costs	2	1
Contributions to qualified pension plans	(8)
Payments for asset retirement obligations	(11)	(7)
Provision for rate refunds	26
(Increase) decrease in
Receivables		44
Receivable from affiliated companies	26	26
Inventory	(3)	26
Other current assets	(23)	(2)
Increase (decrease) in
Accounts payable	21	(32)
Accounts payable to affiliated companies	(5)	1
Taxes accrued	(1)	41
Other current liabilities	(10)	(15)
Other assets	(1)	(11)
Other liabilities		(3)
Net cash provided by operating activities	257	317
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(231)	(189)
Cost of removal, net of salvage	(7)	(15)
Purchases of debt and equity securities	(6)	(4)
Proceeds from sales and maturities of debt and equity securities	3	2
Notes receivable from affiliated companies		(113)
Other	3	3
Net cash used in investing activities	(238)	(316)
CASH FLOWS FROM FINANCING ACTIVITIES
Payments for the redemption of long-term debt		(2)
Notes payable to affiliated companies	(12)
Other	(1)	(1)
Net cash provided by financing activities	(13)	(3)
Net increase (decrease) in cash and cash equivalents	6	(2)
Cash and cash equivalents at beginning of period	9	17
Cash and cash equivalents at end of period	15	15
Significant non-cash transactions:
Accrued capital expenditures	64	84
Piedmont Natural Gas [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (attributable to parent)	110	95
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and accretion (including amortization of nuclear fuel)	39	37
Deferred income taxes	(7)	50
Equity in losses (earnings) of unconsolidated affiliates	(2)	(3)
Accrued pension and other post-retirement benefit costs	(1)	3
Provision for rate refunds	23
(Increase) decrease in
Net realized and unrealized mark-to-market and hedging transactions		(41)
Receivables	22	40
Inventory	37	37
Other current assets	79	24
Increase (decrease) in
Accounts payable	(15)	(31)
Accounts payable to affiliated companies	19	(5)
Taxes accrued	46	2
Other current liabilities	18	(17)
Other assets	4	25
Other liabilities	(1)	(1)
Net cash provided by operating activities	371	215
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures	(121)	(141)
Cost of removal, net of salvage	(2)	(1)
Contributions to equity method investments		(12)
Other	2	(2)
Net cash used in investing activities	(121)	(156)
CASH FLOWS FROM FINANCING ACTIVITIES
Notes payable and commercial paper		(330)
Notes payable to affiliated companies	(257)	261
Net cash provided by financing activities	(257)	(69)
Net increase (decrease) in cash and cash equivalents	(7)	(10)
Cash and cash equivalents at beginning of period	19	25
Cash and cash equivalents at end of period	12	15
Significant non-cash transactions:
Accrued capital expenditures	$ 52	$ 24

XML

Condensed Consolidated Statements of Changes in Equity - USD ($) $ in Millions	Total		Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]		Net Gains (Losses) on Cash Flow Hedges [Member]	Net Unrealized Gains (Losses) on Available for Sale Securities [Member]		Pension and OPEB Adjustments [Member]	Common Stockholders' Equity [Member]		Noncontrolling Interest [Member]	Duke Energy Carolinas [Member]	Duke Energy Carolinas [Member] Members Equity [Member]	Duke Energy Carolinas [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Progress Energy [Member]		Progress Energy [Member] Additional Paid-in Capital [Member]		Progress Energy [Member] Retained Earnings [Member]		Progress Energy [Member] Net Gains (Losses) on Cash Flow Hedges [Member]	Progress Energy [Member] Net Unrealized Gains (Losses) on Available for Sale Securities [Member]		Progress Energy [Member] Pension and OPEB Adjustments [Member]	Progress Energy [Member] Common Stockholders' Equity [Member]		Progress Energy [Member] Noncontrolling Interest [Member]	Duke Energy Progress [Member]	Duke Energy Florida [Member]	Duke Energy Florida [Member] Members Equity [Member]		Duke Energy Florida [Member] Net Unrealized Gains (Losses) on Available for Sale Securities [Member]		Duke Energy Ohio [Member]	Duke Energy Ohio [Member] Common Stock [Member]	Duke Energy Ohio [Member] Additional Paid-in Capital [Member]	Duke Energy Ohio [Member] Retained Earnings [Member]	Duke Energy Indiana [Member]	Piedmont Natural Gas [Member]	Piedmont Natural Gas [Member] Common Stock [Member]	Piedmont Natural Gas [Member] Retained Earnings [Member]
Beginning Balance at Dec. 31, 2016	$ 41,041		$ 1	$ 38,741	$ 2,384		$ (20)	$ (1)		$ (72)	$ 41,033		$ 8				$ 11,807		$ 8,094		$ 3,764		$ (23)	$ 1		$ (16)	$ 11,820		$ (13)
Beginning Balance, in shares at Dec. 31, 2016			700,000,000
Beginning Balance (member's equity) at Dec. 31, 2016														$ 10,772	$ 10,781	$ (9)														$ 7,358	$ 4,900	$ 4,899		$ 1						$ 4,067
Beginning Balance (parent) at Dec. 31, 2016																																				$ 2,996	$ 762	$ 2,695	$ (461)		$ 1,672	$ 860	$ 812
Net income	717				716						716		1				201				199						199		2
Net income (attributable to parent)	716													270	270		199													147	90	90				42			42	91	95		95
Other comprehensive income (loss)	8						3	4		1	8						3						1	1		1	3				1			1
Common stock issuances, including dividend reinvestment and employee benefits, shares			0
Common stock issuances, including dividend reinvestment and employee benefits	1			1							1
Distributions to noncontrolling interest in subsidiaries	(2)												(2)
Distributions/dividends to parent	(600)				(600)						(600)			(175)	(175)
Other	21	[1]			21	[1]					21	[1]					1		0								0		1
Ending Balance at Mar. 31, 2017	41,186		$ 1	38,742	2,521		(17)	3		(71)	41,179		7				12,012		8,094		3,963		(22)	2		(15)	12,022		(10)
Ending Balance, in shares at Mar. 31, 2017			700,000,000
Ending Balance (member's equity) at Mar. 31, 2017														10,867	10,876	(9)														7,505	4,991	4,989		2						4,158
Ending Balance (parent) at Mar. 31, 2017																																				$ 3,038	762	2,695	(419)		$ 1,767	860	907
Beginning Balance at Dec. 31, 2017	$ 41,737		$ 1	38,792	3,013		(10)	12		(69)	41,739		(2)				$ 13,465		9,143		4,350		(18)	5		(12)	13,468		(3)
Beginning Balance, in shares at Dec. 31, 2017	700,000,000		700,000,000														100																			90,000,000					100
Beginning Balance (member's equity) at Dec. 31, 2017														11,361	11,368	(7)														7,949	5,618	5,614		4						4,121
Beginning Balance (parent) at Dec. 31, 2017	$ 41,739																$ 13,468																			$ 3,163	762	2,670	(269)		$ 1,662	860	802
Net income	622				620						620		2				237				235						235		2
Net income (attributable to parent)	620													323	323		235													177	103	103				$ (25)			(25)	100	$ 110		110
Other comprehensive income (loss)	11						13	(3)		1	11			1		1	2						2				2
Common stock issuances, including dividend reinvestment and employee benefits, shares			1,000,000
Common stock issuances, including dividend reinvestment and employee benefits	47			47							47
Distributions to noncontrolling interest in subsidiaries	(1)												(1)
Distributions/dividends to parent	(625)				(625)						(625)			(250)	(250)
Other	7				13	[2]		(13)	[2]				7				(1)	[2]	(1)	[2]	6	[2]		(6)	[2]		(1)	[2]				6	[3]	(6)	[3]
Ending Balance at Mar. 31, 2018	$ 41,798		$ 1	$ 38,839	$ 3,021		$ 3	$ (4)		$ (68)	$ 41,792		$ 6				$ 13,703		$ 9,142		$ 4,591		$ (16)	$ (1)		$ (12)	$ 13,704		$ (1)
Ending Balance, in shares at Mar. 31, 2018	701,000,000		701,000,000														100																			90,000,000					100
Ending Balance (member's equity) at Mar. 31, 2018														$ 11,435	$ 11,441	$ (6)														$ 8,126	$ 5,721	$ 5,723		$ (2)						$ 4,221
Ending Balance (parent) at Mar. 31, 2018	$ 41,792																$ 13,704																			$ 3,138	$ 762	$ 2,670	$ (294)		$ 1,772	$ 860	$ 912

[1] Cumulative-effect adjustment due to implementation of a new accounting standard related to stock-based compensation and the associated income taxes.

[2] Amounts in Retained Earnings and Accumulated Other Comprehensive Loss represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement. See Note 1 for more information.

[3] Amounts in Member's Equity and Accumulated Other Comprehensive Income (Loss) represent a cumulative-effect adjustment due to implementation of a new accounting standard related to Financial Instruments Classification and Measurement. See Note 1 for more information.

XML

Organization and Basis of Presentation

3 Months Ended

Mar. 31, 2018

Accounting Policies [Abstract]

Organization and Basis of Presentation

Index to Combined Notes to Condensed Consolidated Financial Statements

The unaudited notes to the condensed consolidated financial statements that follow are a combined presentation. The following list indicates the registrants to which the footnotes apply.

Applicable Notes

Registrant

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

Duke Energy Corporation

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Carolinas, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Progress Energy, Inc.

•

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Progress, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Florida, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Ohio, Inc.

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Duke Energy Indiana, LLC

•

•

•

•

•

•

•

•

•

•

•

•

•

•

Piedmont Natural Gas Company, Inc.

•

•

•

•

•

•

•

•

•

•

•

•

•

Tables within the notes may not sum across due to (i) Progress Energy's consolidation of Duke Energy Progress, Duke Energy Florida and other subsidiaries that are not registrants and (ii) subsidiaries that are not registrants but included in the consolidated Duke Energy balances.

ORGANIZATION AND BASIS OF PRESENTATION

NATURE OF OPERATIONS AND BASIS OF CONSOLIDATION

Duke Energy Corporation (collectively with its subsidiaries, Duke Energy) is an energy company headquartered in Charlotte, North Carolina, subject to regulation by the Federal Energy Regulatory Commission (FERC). Duke Energy operates in the United States (U.S.) primarily through its direct and indirect subsidiaries. Certain Duke Energy subsidiaries are also subsidiary registrants, including Duke Energy Carolinas, LLC (Duke Energy Carolinas); Progress Energy, Inc. (Progress Energy); Duke Energy Progress, LLC (Duke Energy Progress); Duke Energy Florida, LLC (Duke Energy Florida); Duke Energy Ohio, Inc. (Duke Energy Ohio), Duke Energy Indiana, LLC (Duke Energy Indiana) and Piedmont Natural Gas Company, Inc. (Piedmont). When discussing Duke Energy’s consolidated financial information, it necessarily includes the results of its separate subsidiary registrants (collectively referred to as the Subsidiary Registrants), which, along with Duke Energy, are collectively referred to as the Duke Energy Registrants.

These Condensed Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries where the respective Duke Energy Registrants have control. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities. Substantially all of the Subsidiary Registrants' operations qualify for regulatory accounting.

Duke Energy Carolinas is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Carolinas is subject to the regulatory provisions of the North Carolina Utilities Commission (NCUC), Public Service Commission of South Carolina (PSCSC), U.S. Nuclear Regulatory Commission (NRC) and FERC.

Progress Energy is a public utility holding company headquartered in Raleigh, North Carolina, subject to regulation by FERC. Progress Energy conducts operations through its wholly owned subsidiaries, Duke Energy Progress and Duke Energy Florida.

Duke Energy Progress is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of North Carolina and South Carolina. Duke Energy Progress is subject to the regulatory provisions of the NCUC, PSCSC, NRC and FERC.

Duke Energy Florida is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Florida. Duke Energy Florida is subject to the regulatory provisions of the Florida Public Service Commission (FPSC), NRC and FERC.

Duke Energy Ohio is a regulated public utility primarily engaged in the transmission and distribution of electricity in portions of Ohio and Kentucky, the generation and sale of electricity in portions of Kentucky and the transportation and sale of natural gas in portions of Ohio and Kentucky. Duke Energy Ohio conducts competitive auctions for retail electricity supply in Ohio whereby the energy price is recovered from retail customers and recorded in Operating Revenues on the Condensed Consolidated Statements of Operations and Comprehensive Income. Operations in Kentucky are conducted through its wholly owned subsidiary, Duke Energy Kentucky, Inc. (Duke Energy Kentucky). References herein to Duke Energy Ohio collectively include Duke Energy Ohio and its subsidiaries, unless otherwise noted. Duke Energy Ohio is subject to the regulatory provisions of the Public Utilities Commission of Ohio (PUCO), Kentucky Public Service Commission (KPSC) and FERC.

Duke Energy Indiana is a regulated public utility primarily engaged in the generation, transmission, distribution and sale of electricity in portions of Indiana. Duke Energy Indiana is subject to the regulatory provisions of the Indiana Utility Regulatory Commission (IURC) and FERC.

Piedmont is a regulated public utility primarily engaged in the distribution of natural gas in portions of North Carolina, South Carolina and Tennessee. Piedmont is subject to the regulatory provisions of the NCUC, PSCSC, Tennessee Public Utility Commission (TPUC) and FERC.

BASIS OF PRESENTATION

These Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles (GAAP) in the U.S. for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, these Condensed Consolidated Financial Statements do not include all information and notes required by GAAP in the U.S. for annual financial statements. Since the interim Condensed Consolidated Financial Statements and Notes do not include all information and notes required by GAAP in the U.S. for annual financial statements, the Condensed Consolidated Financial Statements and other information included in this quarterly report should be read in conjunction with the Consolidated Financial Statements and Notes in the Duke Energy Registrants’ combined Annual Report on Form 10-K/A for the year ended December 31, 2017.

The information in these combined notes relates to each of the Duke Energy Registrants as noted in the Index to Combined Notes to Condensed Consolidated Financial Statements. However, none of the registrants make any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself.

These Condensed Consolidated Financial Statements, in the opinion of the respective companies’ management, reflect all normal recurring adjustments necessary to fairly present the financial position and results of operations of each of the Duke Energy Registrants. Amounts reported in Duke Energy’s interim Condensed Consolidated Statements of Operations and each of the Subsidiary Registrants’ interim Condensed Consolidated Statements of Operations and Comprehensive Income are not necessarily indicative of amounts expected for the respective annual periods due to effects of seasonal temperature variations on energy consumption, regulatory rulings, timing of maintenance on electric generating units, changes in mark-to-market valuations, changing commodity prices and other factors.

In preparing financial statements that conform to GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses, and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.

Certain prior year amounts have been reclassified to conform to the current year presentation.

REVENUE

Duke Energy recognizes revenue as customers obtain control of promised goods and services in an amount that reflects consideration expected in exchange for those goods or services. Generally, the delivery of electricity and natural gas results in the transfer of control to customers at the time the commodity is delivered and the amount of revenue recognized is equal to the amount billed to each customer, including estimated volumes delivered when billings have not yet occurred. See Note 12 for further information.

CASH, CASH EQUIVALENTS AND RESTRICTED CASH

Duke Energy, Progress Energy and Duke Energy Florida have restricted cash balances related primarily to collateral assets, escrow deposits and variable interest entities (VIEs). See Note 11 for additional information. Restricted cash amounts are included in Other within Current Assets and Other Noncurrent Assets. The following table presents the components of Cash, cash equivalents and restricted cash included in the Condensed Consolidated Balance Sheets.

	March 31, 2018						December 31, 2017
					Duke						Duke
	Duke		Progress		Energy		Duke		Progress		Energy
	Energy		Energy		Florida		Energy		Energy		Florida
Current Assets
Cash and cash equivalents	$	421	$	20	$	6	$	358	$	40	$	13
Other	149		13		13		138		40		40
Other Noncurrent Assets
Other	9		6		—		9		7		—
Total Cash, cash equivalents and restricted cash	$	579	$	39	$	19	$	505	$	87	$	53

INVENTORY

Inventory is used for operations and is recorded primarily using the average cost method. Inventory related to regulated operations is valued at historical cost. Inventory related to nonregulated operations is valued at the lower of cost or market. Materials and supplies are recorded as inventory when purchased and subsequently charged to expense or capitalized to property, plant and equipment when installed. Inventory, including excess or obsolete inventory, is written-down to the lower of cost or market value. Once inventory has been written-down, it creates a new cost basis for the inventory that is not subsequently written-up. Provisions for inventory write-offs were not material at March 31, 2018, and December 31, 2017. The components of inventory are presented in the tables below.

	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Materials and supplies	$	2,293	$	763	$	1,095	$	767	$	329	$	82	$	310	$	1
Coal	551		176		221		125		96		13		141		—
Natural gas, oil and other fuel	305		41		221		110		110		13		2		28
Total inventory	$	3,149	$	980	$	1,537	$	1,002	$	535	$	108	$	453	$	29

	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Materials and supplies	$	2,293	$	744	$	1,118	$	774	$	343	$	82	$	309	$	2
Coal	603		192		255		139		116		17		139		—
Natural gas, oil and other fuel	354		35		219		104		115		34		2		64
Total inventory	$	3,250	$	971	$	1,592	$	1,017	$	574	$	133	$	450	$	66

EXCISE TAXES

Certain excise taxes levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis. Otherwise, excise taxes are accounted for on a net basis.

Excise taxes accounted for on a gross basis within both Operating revenues and Property and other taxes on the Condensed Consolidated Statements of Operations were as follows.

	Three Months Ended March 31,
(in millions)	2018		2017
Duke Energy	$	99	$	91
Duke Energy Carolinas	8		9
Progress Energy	54		46
Duke Energy Progress	5		5
Duke Energy Florida	49		41
Duke Energy Ohio	30		28
Duke Energy Indiana	6		7
Piedmont	1		1

NEW ACCOUNTING STANDARDS

The new accounting standards adopted for 2018 and 2017 had no material impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. While immaterial, adoption of the following accounting standards had the most significant impact on the Duke Energy results of operations, cash flows and financial position for the three months endedMarch 31, 2018.

Revenue from Contracts with Customers. In May 2014, the Financial Accounting Standards Board (FASB) issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration expected in exchange for those goods or services. The amendments also required disclosure of sufficient information to allow users to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The majority of Duke Energy’s revenue is in scope of the new guidance. Other revenue arrangements, such as alternative revenue programs and certain purchase power agreements (PPAs) and lighting tariffs accounted for as leases, are excluded from the scope of this guidance and, therefore, are accounted for and evaluated for separate presentation and disclosure under other relevant accounting guidance.

Duke Energy elected the modified retrospective method of adoption effective January 1, 2018. Under the modified retrospective method of adoption, prior year reported results are not restated. Adoption of this standard did not result in a material change in the timing or pattern of revenue recognition and a cumulative-effect adjustment was not recorded at January 1, 2018. Duke Energy utilized certain practical expedients including applying this guidance to open contracts at the date of adoption, expensing costs to obtain a contract where the amortization period of the asset would have been one year or less, ignoring the effects of a significant financing when the period between transfer of the good or service and payment is one year or less and recognizing revenues for certain contracts under the invoice practical expedient, which allows revenue recognition to be consistent with invoiced amounts (including estimated billings) provided certain criteria are met, including consideration of whether the invoiced amounts reasonably represent the value provided to customers.

In preparation for adoption, Duke Energy identified material revenue streams and reviewed representative contracts and tariffs, including those associated with certain long-term customer contracts such as wholesale contracts, PPAs, and other customer arrangements. Duke Energy also monitored the activities of the power and utilities industry revenue recognition task force and has reviewed published positions on specific industry issues to evaluate the impact, if any, on Duke Energy’s specific contracts and conclusions.

Duke Energy applied the available practical expedient to portfolios of tariffs and contracts with similar characteristics. The vast majority of sales, including energy provided to retail customers, are from tariff offerings that provide natural gas or electricity without a defined contractual term ("at-will"). In most circumstances, revenue from contracts with customers is equivalent to the electricity or natural gas supplied and billed in that period (including estimated billings). As such, adoption of the new rules did not result in a shift in the timing or pattern of revenue recognition for such sales. While there have been changes to the captions and descriptions of revenues in Duke Energy’s financial statements, the most significant impact as a result of adopting the standard are additional disclosures around the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. See Note 12 for further information.

Financial Instruments Classification and Measurement. In January 2018, Duke Energy adopted FASB guidance, which revised the classification and measurement of certain financial instruments. The adopted guidance changes the presentation of realized and unrealized gains and losses in certain equity securities that were previously recorded in accumulated other comprehensive income (AOCI). These gains and losses are now recorded in net income. An entity's equity investments that are accounted for under the equity method of accounting are not included within the scope of the new guidance. This guidance had a minimal impact on the Duke Energy Registrant's Condensed Consolidated Statements of Operations and Comprehensive Income as changes in the fair value of most of the Duke Energy Registrants' equity securities are deferred as regulatory assets or liabilities pursuant to accounting guidance for regulated operations. The resulting adjustment of unrealized gains and losses in AOCI to retained earnings was immaterial. The primary impact to Duke Energy as a result of implementing this guidance is adding disclosure requirements to present separately the financial assets and financial liabilities by measurement category and form of financial asset. See Notes 9 and 10 for further information.

Statement of Cash Flows. In November 2016, the FASB issued revised accounting guidance to reduce diversity in practice for the presentation and classification of restricted cash on the Condensed Consolidated Statements of Cash Flows. Under the updated guidance, restricted cash and restricted cash equivalents are included within beginning-of-period and end-of-period cash and cash equivalents on the Condensed Consolidated Statements of Cash Flows. Duke Energy adopted this guidance on January 1, 2018. The guidance has been applied using a retrospective transition method to each period presented. The adoption by Duke Energy of the revised guidance resulted in a change to the amount of Cash, cash equivalents and restricted cash explained when reconciling the beginning-of-period and end-of-period total amounts shown on the Condensed Consolidated Statements of Cash Flows. In addition, a reconciliation has been provided of Cash, cash equivalents and restricted cash reported within the Condensed Consolidated Balance Sheets that sums to the total of the same such amounts in the Condensed Consolidated Statements of Cash Flows. Prior to adoption, the Duke Energy Registrants reflected changes in noncurrent restricted cash within Cash Flows from Investing Activities and changes in current restricted cash within Cash Flows from Operating Activities on the Condensed Consolidated Statement of Cash Flows.

In August 2016, the FASB issued accounting guidance addressing diversity in practice for eight separate cash flow issues. The guidance requires entities to classify distributions received from equity method investees using either the cumulative earnings approach or the nature of the distribution approach. Duke Energy adopted this guidance on January 1, 2018, and has elected the nature of distribution approach. Duke Energy will categorize all distributions received based on legal documentation describing the nature of the activities generating the distribution. Cash inflows resulting in a return on investment (surplus) will be reflected in Cash Flows from Operating Activities on the Condensed Consolidated Statements of Cash Flows, whereas cash inflows resulting in a return of investment (capital) will be reflected in Cash Flows from Investing Activities on the Condensed Consolidated Statements of Cash Flows. The guidance has been applied using the retrospective transition method to each period presented. There are no changes to the Condensed Consolidated Statements of Cash Flows for the periods presented as a result of this accounting change.

Retirement Benefits. In March 2017, the FASB issued revised accounting guidance for the presentation of net periodic costs related to benefit plans. Previous guidance required the aggregation of all the components of net periodic costs on the Condensed Consolidated Statement of Operations and did not require the disclosure of the location of net periodic costs on the Condensed Consolidated Statement of Operations. Under the amended guidance, the service cost component of net periodic costs is included within Operating Income within the same line as other compensation expenses. All other components of net periodic costs are outside of Operating Income. In addition, the updated guidance permits only the service cost component of net periodic costs to be capitalized to Inventory or Property, Plant and Equipment. This represents a change from previous guidance, which permitted all components of net periodic costs to be eligible for capitalization.

Duke Energy adopted this guidance on January 1, 2018. Under previous guidance, Duke Energy presented the total non-capitalized net periodic costs within Operation, maintenance and other on the Condensed Consolidated Statement of Operations. The adoption of this guidance resulted in a retrospective change to reclassify the presentation of the non-service cost (benefit) components of net periodic costs to Other income and expenses. Duke Energy utilized the practical expedient for retrospective presentation. The change in components of net periodic costs eligible for capitalization is applicable prospectively. Since Duke Energy’s service cost component is greater than the total net periodic costs, the change results in increased capitalization of net periodic costs, higher Operation, maintenance and other and higher Other income and expenses. The resulting prospective impact to Duke Energy is an immaterial increase in Net Income. See Note 15 for further information.

For Duke Energy, the retrospective change resulted in higher Operation, maintenance and other and higher Other income and expenses, net, of $156 million, $131 million and $96 million for the years ended December 31, 2017, 2016 and 2015, respectively. There was no change to Net Income for these prior periods.

The following new Accounting Standards Updates (ASUs) have been issued, but have not yet been adopted by Duke Energy, as of March 31, 2018.

Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet.

For Duke Energy, this guidance is effective for interim and annual periods beginning January 1, 2019. The guidance will be applied using a modified retrospective approach. Upon adoption, Duke Energy expects to elect certain of the practical expedients upon adoption:

Practical Expedient	Description
Package of transition practical expedients (for leases commenced prior to adoption date and must be adopted as a package)	Do not need to reassess whether any expired or existing contracts are/or contain leases, do not need to reassess the lease classification for any expired or existing leases and do not need to reassess initial direct costs for any existing leases.
Short-term lease expedient (elect by class of underlying asset)	Elect as an accounting policy to not apply the recognition requirements to short-term leases by asset class.
Lease and non-lease components (elect by class of underlying asset)	Duke Energy will likely elect as an accounting policy to not separate non-lease components from lease components and instead account for each lease and associated non-lease component as a single lease component.
Hindsight expedient (when determining lease term)	Elect to use hindsight to determine the lease term.
Easement expedient	Elect to carry forward current accounting treatment for existing easements.

Duke Energy is currently evaluating the financial statement impact of adopting this standard and is continuing to monitor industry implementation issues, including pipeline laterals, pole attachments and renewable PPAs. Other than an expected increase in assets and liabilities, the ultimate impact of the new standard has not yet been determined. Significant system enhancements, including additional processes and controls, will be required to facilitate the identification, tracking and reporting of potential leases based upon requirements of the new lease standard. Duke Energy has begun the implementation of a third-party software tool to help with the adoption and ongoing accounting under the new standard.

XML

Business Segments

3 Months Ended

Mar. 31, 2018

Segment Reporting [Abstract]

Business Segments

BUSINESS SEGMENTS

Operating segments are determined based on information used by the chief operating decision-maker in deciding how to allocate resources and evaluate the performance of the business. Duke Energy evaluates segment performance based on segment income. Segment income is defined as income from continuing operations net of income attributable to noncontrolling interests. Segment income includes intercompany revenues and expenses that are eliminated on the Condensed Consolidated Financial Statements. Certain governance costs are allocated to each segment. In addition, direct interest expense and income taxes are included in segment income.

Duke Energy

Duke Energy's segment structure includes the following segments: Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables.

The Electric Utilities and Infrastructure segment includes Duke Energy's regulated electric utilities in the Carolinas, Florida and the Midwest. The regulated electric utilities conduct operations through the Subsidiary Registrants that are substantially all regulated and, accordingly, qualify for regulatory accounting treatment. Electric Utilities and Infrastructure also includes Duke Energy's electric transmission infrastructure investments.

The Gas Utilities and Infrastructure segment includes Piedmont, Duke Energy's natural gas local distribution companies in Ohio and Kentucky, and Duke Energy's natural gas storage and midstream pipeline investments. Gas Utilities and Infrastructure's operations are substantially all regulated and, accordingly, qualify for regulatory accounting treatment.

Commercial Renewables is primarily comprised of nonregulated utility scale wind and solar generation assets located throughout the U.S.

The remainder of Duke Energy’s operations is presented as Other, which is primarily comprised of interest expense on holding company debt, unallocated corporate costs and Duke Energy’s wholly owned captive insurance company, Bison Insurance Company Limited (Bison). Other also includes Duke Energy's 17.5 percent interest in National Methanol Company (NMC), a large regional producer of methyl tertiary butyl ether located in Saudi Arabia. The investment in NMC is accounted for under the equity method of accounting.

Business segment information is presented in the following tables. Segment assets presented exclude intercompany assets.

	Three Months Ended March 31, 2018
	Electric		Gas				Total
	Utilities and		Utilities and		Commercial		Reportable
(in millions)	Infrastructure		Infrastructure		Renewables		Segments		Other			Eliminations			Consolidated
Unaffiliated revenues	$	5,315	$	702	$	101	$	6,118	$	17		$	—		$	6,135
Intersegment revenues	8		25		—		33		18			(51		)	—
Total revenues	$	5,323	$	727	$	101	$	6,151	$	35		$	(51	)	$	6,135
Segment income (loss)(a)(b)(c)	$	750	$	116	$	20	$	886	$	(266	)	$	—		$	620
Add back noncontrolling interests															2
Net income															$	622
Segment assets	$	120,021	$	11,396	$	4,265	$	135,682	$	2,682		$	177		$	138,541

	Three Months Ended March 31, 2017
	Electric		Gas				Total
	Utilities and		Utilities and		Commercial		Reportable
(in millions)	Infrastructure		Infrastructure		Renewables		Segments		Other			Eliminations			Consolidated
Unaffiliated revenues	$	4,939	$	648	$	128	$	5,715	$	14		$	—		$	5,729
Intersegment revenues	8		22		—		30		19			(49		)	—
Total revenues	$	4,947	$	670	$	128	$	5,745	$	33		$	(49	)	$	5,729
Segment income (loss)	$	635	$	133	$	25	$	793	$	(77	)	$	—		$	716
Add back noncontrolling interests															1
Net income															$	717

(a) Electric Utilities and Infrastructure includes regulatory charges related to NCUC orders and settlements. See Note 3 for additional information.

(b) Gas Utilities and Infrastructure includes an impairment of the investment in Constitution Pipeline Company, LLC (Constitution). See Note 3 for additional information.

(c) Other includes the loss on the sale of the retired Beckjord generating station (Beckjord) described below and a valuation allowance recorded against the alternative minimum tax credits subject to sequestration. See Note 16 for additional information on the valuation allowance.

Beckjord, a nonregulated facility retired during 2014, was sold on February 26, 2018, at a pretax loss of $106 million recorded within (Loss) Gains on Sales of Other Assets and Other, net and $1 million recorded within Operation, maintenance and other on Duke Energy's Condensed Consolidated Statements of Operations. The sale included the transfer of coal ash basins and other real property and indemnification from any and all potential future claims related to the property, whether arising under environmental laws or otherwise.

Duke Energy Ohio

Duke Energy Ohio has two reportable operating segments, Electric Utilities and Infrastructure and Gas Utilities and Infrastructure.

Electric Utilities and Infrastructure transmits and distributes electricity in portions of Ohio and generates, distributes and sells electricity in portions of Northern Kentucky. Gas Utilities and Infrastructure transports and sells natural gas in portions of Ohio and Northern Kentucky. It conducts operations primarily through Duke Energy Ohio and its wholly owned subsidiary, Duke Energy Kentucky.

The remainder of Duke Energy Ohio's operations is presented as Other, which is primarily comprised of governance costs allocated by its parent, Duke Energy, and revenues and expenses related to Duke Energy Ohio's contractual arrangement to buy power from the Ohio Valley Electric Corporation's (OVEC) power plants. See Note 7 for additional information on related party transactions.

	Three Months Ended March 31, 2018
	Electric		Gas		Total
	Utilities and		Utilities and		Reportable
(in millions)	Infrastructure		Infrastructure		Segments		Other			Eliminations			Consolidated
Total revenues	$	336	$	174	$	510	$	14		$	—		$	524
Segment income (loss)/Net income (loss)(a)	33		34		67		(92		)	—			(25		)
Segment assets	$	5,165	$	2,709	$	7,874	$	25		$	(3	)	$	7,896

	Three Months Ended March 31, 2017
	Electric		Gas		Total
	Utilities and		Utilities and		Reportable
(in millions)	Infrastructure		Infrastructure		Segments		Other			Consolidated
Total revenues	$	337	$	170	$	507	$	11		$	518
Segment income (loss)/Net income (loss)	24		26		50		(8		)	42

(a) Other includes the loss on the sale of the retired Beckjord generating station described above.

XML

Regulatory Matters

3 Months Ended

Mar. 31, 2018

Regulated Operations [Abstract]

Regulatory Matters

REGULATORY MATTERS

RATE-RELATED INFORMATION

The NCUC, PSCSC, FPSC, IURC, PUCO, TPUC and KPSC approve rates for retail electric and natural gas services within their states. The FERC approves rates for electric sales to wholesale customers served under cost-based rates (excluding Ohio and Indiana), as well as sales of transmission service. The FERC also regulates certification and siting of new interstate natural gas pipeline projects.

Duke Energy Carolinas and Duke Energy Progress

Ash Basin Closure Costs Deferral – North Carolina

On December 30, 2016, Duke Energy Carolinas and Duke Energy Progress filed a joint petition with the NCUC seeking an accounting order authorizing deferral of certain costs incurred in connection with federal and state environmental remediation requirements related to the permanent closure of ash basins and other ash storage units at coal-fired generating facilities that have provided or are providing generation to customers located in North Carolina. Initial comments were received in March 2017, and reply comments were filed on April 19, 2017. The NCUC has consolidated Duke Energy Carolinas' and Duke Energy Progress’ coal ash deferral requests into their respective general rate case dockets for decision. See "2017 North Carolina Rate Case" sections below for additional discussion. Duke Energy Carolinas is still awaiting an order in its case and, as such, cannot predict the outcome of this matter.

Duke Energy Carolinas

2017 North Carolina Rate Case

On August 25, 2017, Duke Energy Carolinas filed an application with the NCUC for a rate increase for retail customers of approximately $647 million, which represents an approximate 13.6 percent increase in annual base revenues. The rate increase is driven by capital investments subsequent to the previous base rate case, including the William States Lee Combined Cycle Facility discussed below, grid improvement projects, AMI, investments in customer service technologies, costs of complying with coal combustion residuals (CCR) regulations and the North Carolina Coal Ash Management Act of 2014 (Coal Ash Act) and recovery of costs related to licensing and development of the William States Lee III Nuclear Station (Lee Nuclear Station) discussed below. On February 28, 2018, Duke Energy Carolinas and the North Carolina Public Staff filed an Agreement and Stipulation of Partial Settlement resolving certain portions of the proceeding, pending NCUC approval. Terms of the settlement include a return on equity of 9.9 percent and a capital structure of 52 percent equity and 48 percent debt. As a result of the settlement, Duke Energy Carolinas recorded a pretax charge of approximately $4 million to Operations, maintenance and other on the Condensed Consolidated Statements of Operations. The settlement does not include agreement on portions of the rate case relating to recovery of costs for Lee Nuclear Station and coal ash basin deferred costs, a rider for recovery of grid improvement projects or the manner in which the Federal Tax Cut and Jobs Act (Tax Act) should be addressed in this case, which will be decided by the NCUC separately. Taking into consideration the settled portions and Duke Energy Carolinas’ requested recovery of the non-settled portions, the requested base rate increase is reduced to approximately $472 million. The evidentiary hearing for this matter concluded on March 22, 2018, and a decision and revised customer rates are expected by mid–2018. Duke Energy Carolinas cannot predict the outcome of this matter.

FERC Formula Rate Matter

On July 31, 2017, Piedmont Municipal Power Agency (PMPA) filed a complaint with FERC against Duke Energy Carolinas alleging that Duke Energy Carolinas misapplied the formula rate under the PPA between the parties by including in its rates amortization expense associated with regulatory assets and recorded in a certain account without FERC approval. Duke Energy Carolinas disagreed with PMPA as it believed it was properly applying its FERC filed rate. On February 15, 2018, FERC issued an order ruling in favor of PMPA and ordered Duke Energy Carolinas to refund to PMPA all amounts improperly collected under the PPA. Duke Energy Carolinas has issued to PMPA and similarly situated wholesale customers refunds of approximately $25 million.

William States Lee Combined Cycle Facility

On April 9, 2014, the PSCSC granted Duke Energy Carolinas and North Carolina Electric Membership Corporation (NCEMC) a Certificate of Environmental Compatibility and Public Convenience and Necessity for the construction and operation of a 750-megawatt (MW) combined-cycle natural gas-fired generating plant at Duke Energy Carolinas' existing William States Lee Generating Station in Anderson, South Carolina. Duke Energy Carolinas began construction in July 2015 and its share of the cost to build the facility was approximately $650 million, including allowance for funds used during construction (AFUDC). The project commenced commercial operation on April 5, 2018. NCEMC will own approximately 13 percent of the project.

Lee Nuclear Station

In December 2007, Duke Energy Carolinas applied to the NRC for combined operating licenses (COLs) for two Westinghouse Electric Company (Westinghouse) AP1000 reactors for the proposed William States Lee III Nuclear Station to be located at a site in Cherokee County, South Carolina. The NCUC and PSCSC concurred with the prudency of Duke Energy Carolinas incurring certain project development and preconstruction costs through several separately issued orders, although full cost recovery is not guaranteed. In December 2016, the NRC issued a COL for each reactor. Duke Energy Carolinas is not required to build the nuclear reactors as a result of the COLs being issued.

On March 29, 2017, Westinghouse filed for voluntary Chapter 11 bankruptcy in the U.S. Bankruptcy Court for the Southern District of New York. As part of its 2017 North Carolina Rate Case discussed above, Duke Energy Carolinas is seeking NCUC approval to cancel the development of the Lee Nuclear Station project due to the Westinghouse bankruptcy filing and other market activity and is requesting recovery of incurred licensing and development costs. Duke Energy Carolinas will maintain the license issued by the NRC in December 2016 as an option for potential future development. AFUDC was suspended effective January 1, 2018, as currently only immaterial costs to maintain the license are being incurred. As of March 31, 2018, Duke Energy Carolinas has incurred approximately $558 million of costs, including AFUDC, related to the project. These project costs are included in Net property, plant and equipment on Duke Energy Carolinas’ Condensed Consolidated Balance Sheets. Duke Energy Carolinas cannot predict the outcome of this matter.

Duke Energy Progress

2017 North Carolina Rate Case

On June 1, 2017, Duke Energy Progress filed an application with the NCUC for a rate increase for retail customers of approximately $477 million, which represented an approximate 14.9 percent increase in annual base revenues. Subsequent to the filing, Duke Energy Progress adjusted the requested amount to $420 million, representing an approximate 13 percent increase. The rate increase is driven by capital investments subsequent to the previous base rate case, costs of complying with CCR regulations and the Coal Ash Act, costs relating to storm recovery, investments in customer service technologies and recovery of costs associated with renewable purchased power.

On December 16, 2016, Duke Energy Progress filed a petition with the NCUC requesting an accounting order to defer certain costs incurred in connection with response to Hurricane Matthew and other significant storms in 2016. The final estimate of incremental operation and maintenance and capital costs of $116 million was filed with the NCUC in September 2017. On July 10, 2017, the NCUC consolidated Duke Energy Progress' storm deferral request into the Duke Energy Progress rate case docket for decision.

On November 22, 2017, Duke Energy Progress and the North Carolina Public Staff filed an Agreement and Stipulation of Partial Settlement resolving certain portions of the proceeding. Terms of the settlement included a return on equity of 9.9 percent and a capital structure of 52 percent equity and 48 percent debt. As a result of the settlement, in 2017 Duke Energy Progress recorded pretax charges totaling approximately $25 million to Impairment charges and Operation, maintenance and other on the Condensed Consolidated Statements of Operations, principally related to disallowances from rate base of certain projects at the Mayo and Sutton plants. On February 23, 2018, the NCUC issued an order approving the stipulation. The order also included the following material components not covered in the stipulation:

• recovery of the remaining $234 million of deferred coal ash basin closure costs over a five-year period with a return at Duke Energy Progress' weighted average cost of capital, excluding $9.5 million of retail deferred coal ash basin costs related to ash hauling at Duke Energy Progress' Asheville Plant;

• assessment of a $30 million management penalty ratably over a five-year period by reducing the annual recovery of the deferred coal ash costs;

• denial of Duke Energy Progress' request for recovery of future estimated ongoing annual coal ash costs of $129 million with approval to defer such costs with a return at Duke Energy Progress' weighted average cost of capital, to be considered for recovery in the next rate case;

• and approval to recover $51 million of the approximately $80 million deferred storm costs over a five-year period with amortization beginning in October 2016. The order did not allow the deferral of the associated capital costs or a return on the deferred balance during the deferral period.

The order also impacted certain amounts that were similarly recorded on Duke Energy Carolinas' Condensed Consolidated Balance Sheets. As a result of the order, Duke Energy Progress and Duke Energy Carolinas recorded pretax charges of $68 million and $14 million, respectively, in the first quarter of 2018 to Impairment charges, Operation, maintenance and other and Interest Expense on the Condensed Consolidated Statements of Operations. These charges primarily related to the coal ash basin disallowance and management penalty and deferred storm cost adjustments. Revised customer rates became effective on March 16, 2018.

South Carolina Rate Case

In December 2016, the PSCSC approved a rate case settlement agreement among the Office of Regulatory Staff, intervenors and Duke Energy Progress. Terms of the settlement agreement included an approximate $56 million increase in revenues over a two-year period. An increase of approximately $38 million in revenues was effective January 1, 2017, and an additional increase of approximately $18.5 million in revenues was effective January 1, 2018. Duke Energy Progress amortized approximately $18.5 million from the cost of removal reserve in 2017. Other settlement terms included a rate of return on equity of 10.1 percent, recovery of coal ash costs incurred from January 1, 2015, through June 30, 2016, over a 15‑year period and ongoing deferral of allocated ash basin closure costs from July 1, 2016, until the next base rate case. The settlement also provides that Duke Energy Progress will not seek an increase in rates in South Carolina to occur prior to 2019, with limited exceptions.

Western Carolinas Modernization Plan

On November 4, 2015, Duke Energy Progress announced a Western Carolinas Modernization Plan, which included retirement of the existing Asheville coal-fired plant, the construction of two 280‑MW combined-cycle natural gas plants having dual-fuel capability, with the option to build a third natural gas simple cycle unit in 2023 based upon the outcome of initiatives to reduce the region's power demand. The plan also included upgrades to existing transmission lines and substations, installation of solar generation and a pilot battery storage project. These investments will be made within the next seven years. Duke Energy Progress is also working with the local natural gas distribution company to upgrade an existing natural gas pipeline to serve the natural gas plant.

On March 28, 2016, the NCUC issued an order approving a CPCN for the new combined-cycle natural gas plants, but denying the CPCN for the contingent simple cycle unit without prejudice to Duke Energy Progress to refile for approval in the future. On March 28, 2018, Duke Energy Progress filed an annual progress report for the construction of the combined-cycle plants with the NCUC, with an estimated cost of $893 million. Site preparation activities for the combined-cycle plants are complete and construction of these plants began in 2017, with an expected in-service date in late 2019. Duke Energy Progress plans to file for future approvals related to the proposed solar generation and pilot battery storage project.

The carrying value of the 376-MW Asheville coal-fired plant, including associated ash basin closure costs, of $365 million and $385 million is included in Generation facilities to be retired, net on Duke Energy Progress' Condensed Consolidated Balance Sheets as of March 31, 2018, and December 31, 2017, respectively. Duke Energy Progress' request for a regulatory asset at the time of retirement with amortization over a 10-year period was approved by the NCUC on February 23, 2018.

Shearon Harris Nuclear Plant Expansion

In 2006, Duke Energy Progress selected a site at Harris to evaluate for possible future nuclear expansion. On February 19, 2008, Duke Energy Progress filed its COL application with the NRC for two Westinghouse AP1000 reactors at Harris, which the NRC docketed for review. On May 2, 2013, Duke Energy Progress filed a letter with the NRC requesting the NRC to suspend its review activities associated with the COL at the Harris site. The NCUC and PSCSC approved deferral of retail costs. Total deferred costs were approximately $47 million as of December 31, 2017, and are recorded in Regulatory assets on Duke Energy Progress’ Condensed Consolidated Balance Sheets. On November 17, 2016, the FERC approved Duke Energy Progress’ rate recovery request filing for the wholesale ratepayers’ share of the abandonment costs, including a debt only return to be recovered through revised formula rates and amortized over a 15-year period beginning May 1, 2014. As part of the settlement agreement for the 2017 North Carolina Rate Case discussed above, Duke Energy Progress will amortize the regulatory asset over an eight-year period. NCUC approved the settlement on February 23, 2018.

Duke Energy Florida

Storm Restoration Cost Recovery

In September 2017, Duke Energy Florida’s service territory suffered significant damage from Hurricane Irma, resulting in approximately 1.3 million customers experiencing outages. In the fourth quarter of 2017, Duke Energy Florida also incurred preparation costs related to Hurricane Nate. On December 28, 2017, Duke Energy Florida filed a petition with the FPSC to recover incremental storm restoration costs for hurricanes Irma and Nate and to replenish the storm reserve. The estimated recovery amount is approximately $513 million, which includes reestablishment of a $132 million storm reserve. On February 6, 2018, the FPSC approved a stipulation that would apply tax savings resulting from the Tax Act toward storm costs effective January 2018 in lieu of implementing a storm surcharge. Storm costs are currently expected to be fully recovered by approximately mid-2021. The evidentiary hearing in this matter is scheduled for the week of October 15, 2018. At March 31, 2018, Duke Energy Florida's Condensed Consolidated Balance Sheets included approximately $338 million of recoverable costs under the FPSC's storm rule in Regulatory assets within Current Assets and Other Noncurrent Assets related to storm recovery.

Citrus County Combined Cycle Facility

On October 2, 2014, the FPSC granted Duke Energy Florida a Determination of Need for the construction of a 1,640-MW combined-cycle natural gas plant in Citrus County, Florida. On May 5, 2015, the Florida Department of Environmental Protection approved Duke Energy Florida's Site Certification Application. The project has received all required permits and approvals and construction began in October 2015. The facility is expected to be commercially available by the end of 2018 at an estimated cost of $1.5 billion, including AFUDC. On April 2, 2018, Duke Energy Florida filed a petition seeking approval to include in base rates the revenue requirements associated with the new facility. The annual retail revenue requirement is approximately $200 million. The plant will receive natural gas from the Sabal Trail Transmission, LLC (Sabal Trail) pipeline discussed below.

Duke Energy Ohio

2017 Electric Security Plan Filing

On June 1, 2017, Duke Energy Ohio filed with the PUCO a request for a standard service offer in the form of an electric security plan (ESP). If approved by the PUCO, the term of the ESP would be from June 1, 2018, to May 31, 2024. Terms of the ESP include continuation of market-based customer rates through competitive procurement processes for generation, continuation and expansion of existing rider mechanisms and proposed new rider mechanisms relating to regulatory mandates, costs incurred to enhance the customer experience and transform the grid and a service reliability rider for vegetation management. On February 15, 2018, the procedural schedule was suspended to facilitate ongoing settlement discussions. On April 13, 2018, Duke Energy Ohio filed a Motion to consolidate this proceeding with several other cases currently pending before the Commission, including, but not limited to, its Electric Base Rate Case. Additionally, on April 13, 2018, Duke Energy Ohio, along with certain intervenors, filed a Stipulation and Recommendation (Stipulation) with the PUCO resolving certain issues in this proceeding. The Stipulation establishes a regulatory model for the next seven years via the approval of the ESP and continues the current model for procuring supply for non-shopping customers, including recovery mechanisms. The Stipulation is subject to the review and approval of PUCO. An evidentiary hearing to review the Stipulation and other issues in the cases will be scheduled at a later date. Duke Energy Ohio cannot predict the outcome of this matter.

Electric Base Rate Case

Duke Energy Ohio filed with the PUCO an electric distribution base rate case application and supporting testimony in March 2017. Duke Energy Ohio has requested an estimated annual increase of approximately $15 million and a return on equity of 10.4 percent. The application also includes requests to continue certain current riders and establish new riders. On September 26, 2017, the PUCO staff filed a report recommending a revenue decrease between approximately $18 million and $29 million and a return on equity between 9.22 percent and 10.24 percent. On February 15, 2018, the procedural schedule was suspended to facilitate ongoing settlement discussions. On April 13, 2018, Duke Energy Ohio filed a Motion to consolidate this proceeding with several other cases currently pending before the Commission. On April 13, 2018, Duke Energy Ohio, along with certain intervenors, filed the Stipulation with the PUCO resolving certain issues in this proceeding. Major components of the Stipulation include a $19 million annual base distribution rate decrease with a return on equity of 9.84 percent based upon a capital structure of 50.75 percent equity and 49.25 percent debt. Upon approval of new rates, Duke Energy Ohio's rider for recovering its initial SmartGrid implementation ends as the costs will be recovered through base rates. The Stipulation also renews 14 existing riders, some of which were included in the Company's ESP, and two new riders including the Enhanced Service Reliability Rider to recover vegetation management costs not included in base rates, up to $10 million per year (operation and maintenance only) and the Power Forward Rider to recover costs incurred to enhance the customer experience and further transform the grid (operation and maintenance and capital). The Stipulation is subject to the review and approval of PUCO. An evidentiary hearing to review the Stipulation and other issues in the cases will be scheduled at a later date. Duke Energy Ohio has requested new rates go into effect June 1, 2018. In addition to the changes in revenue attributable to the Stipulation, Duke Energy Ohio’s capital-related riders, including the Distribution Capital Investments Rider, will begin to reflect the lower federal income tax rate associated with the Tax Act beginning with updates to be reflected in customers’ bills beginning April 1, 2018. At that time, all impacts of the lower federal income tax rate will be incorporated into customer rates, resulting in lower electric revenue of approximately $20 million on an annualized basis. All other implications of the Tax Act, including the quantification and timing of any refunds associated with excess accumulated deferred income taxes, will be deferred to PUCO’s open investigation, which is pending. Duke Energy Ohio cannot predict the outcome of this matter.

Ohio Valley Electric Corporation

On March 31, 2017, Duke Energy Ohio filed for approval to adjust its existing price stabilization rider (Rider PSR), which is currently set at zero dollars, to pass through net costs related to its contractual entitlement to capacity and energy from the generating assets owned by OVEC. Duke Energy Ohio is seeking deferral authority for net costs incurred from January 1, 2018, until the new rates under Rider PSR are put into effect. Various intervenors have filed motions to dismiss or stay the proceeding and Duke Energy Ohio has opposed these filings. On April 13, 2018, Duke Energy Ohio filed a Motion to consolidate this proceeding with several other cases currently pending before the Commission. Also on April 13, 2018, Duke Energy Ohio, along with certain intervenors, filed a Stipulation with the PUCO resolving certain issues in this proceeding. The Stipulation, if approved, would activate Rider PSR for recovery of net costs incurred since January 1, 2018. The Stipulation is subject to the review and approval of PUCO. An evidentiary hearing to review the Stipulation and other issues in the cases will be scheduled at a later date. See Note 11 for additional discussion of Duke Energy Ohio's ownership interest in OVEC. Duke Energy Ohio cannot predict the outcome of this matter.

Energy Efficiency Cost Recovery

On March 28, 2014, Duke Energy Ohio filed an application for recovery of program costs, lost distribution revenue and performance incentives related to its energy efficiency and peak demand reduction programs. These programs are undertaken to comply with environmental mandates set forth in Ohio law. The PUCO approved Duke Energy Ohio’s application but found that Duke Energy Ohio was not permitted to use banked energy savings from previous years in order to calculate the amount of allowed incentive. This conclusion represented a change to the cost recovery mechanism that had been agreed upon by intervenors and approved by the PUCO in previous cases. The PUCO granted the applications for rehearing filed by Duke Energy Ohio and an intervenor. On January 6, 2016, Duke Energy Ohio and the PUCO Staff entered into a stipulation, pending the PUCO's approval, to resolve issues related to performance incentives and the PUCO Staff audit of 2013 costs, among other issues. In December 2015, based upon the stipulation, Duke Energy Ohio re-established approximately $20 million of the revenues that had been previously reversed. On October 26, 2016, the PUCO issued an order approving the stipulation without modification. In December 2016, the PUCO granted the intervenors request for rehearing for the purpose of further review. Duke Energy Ohio cannot predict the outcome of this matter.

On June 15, 2016, Duke Energy Ohio filed an application for approval of a three-year energy efficiency and peak demand reduction portfolio of programs. A stipulation and modified stipulation were filed on December 22, 2016, and January 27, 2017, respectively. Under the terms of the stipulations, which included support for deferral authority of all costs and a cap on shared savings incentives, Duke Energy Ohio has offered its energy efficiency and peak demand reduction programs throughout 2017. On February 3, 2017, Duke Energy Ohio filed for deferral authority of its costs incurred in 2017 in respect of its proposed energy efficiency and peak demand reduction portfolio. On September 27, 2017, the PUCO issued an order approving a modified stipulation. The modifications impose an annual cap of approximately $38 million on program costs and shared savings incentives combined, but allowed for Duke Energy Ohio to file for a waiver of costs in excess of the cap in 2017. The PUCO approved the waiver request up to a total cost of $56 million. On November 21, 2017, the PUCO granted Duke Energy Ohio's and intervenor's applications for rehearing of the September 27, 2017, order. On January 10, 2018, the PUCO denied the Ohio Consumers' Counsel’s application for rehearing of the PUCO order granting Duke Energy Ohio's waiver request. Duke Energy Ohio cannot predict the outcome of this matter.

2014 Electric Security Plan

In April 2015, the PUCO modified and approved Duke Energy Ohio's proposed ESP, with a three-year term and an effective date of June 1, 2015. The PUCO approved a competitive procurement process for SSO load, a distribution capital investment rider and a tracking mechanism for incremental distribution expenses caused by major storms. The PUCO also approved a placeholder tariff for a price stabilization rider, but denied Duke Energy Ohio's specific request to include Duke Energy Ohio's entitlement to generation from OVEC in the rider at this time; however, the order allows Duke Energy Ohio to submit additional information to request recovery in the future. On May 4, 2015, Duke Energy Ohio filed an application for rehearing requesting the PUCO to modify or amend certain aspects of the order. On May 28, 2015, the PUCO granted all applications for rehearing filed in the case for future consideration. On March 21, 2018, the PUCO issued an order denying the Company's issues on rehearing. On April 20, 2018, Duke Energy Ohio filed a second application for rehearing based upon the Commission’s March 21, 2018, Order.

Natural Gas Pipeline Extension

Duke Energy Ohio is proposing to install a new natural gas pipeline (the Central Corridor Project) in its Ohio service territory to increase system reliability and enable the retirement of older infrastructure. The pipeline is expected to cost approximately $112 million, excluding AFUDC. On January 20, 2017, Duke Energy Ohio filed an amended application with the Ohio Power Siting Board (OPSB) for approval of one of two proposed routes. A public hearing was held on June 15, 2017, and an adjudicatory hearing was scheduled to begin September 11, 2017. On August 24, 2017, an administrative law judge (ALJ) granted a request made by Duke Energy Ohio to delay the procedural schedule while it works through various issues related to the pipeline route. In April 2018, Duke Energy Ohio filed a motion with OPSB to establish a procedural schedule and filed supplemental information supporting its application. If approved, construction of the pipeline extension is expected to be completed before the 2020/2021 winter season. Duke Energy Ohio cannot predict the outcome of this matter.

Duke Energy Kentucky Rate Case

On September 1, 2017, Duke Energy Kentucky filed a rate case with the KPSC requesting an increase in electric base rates of approximately $49 million, which represents an approximate 15 percent increase on the average customer bill. Subsequent to the filing, Duke Energy Kentucky adjusted the requested amount to $30.1 million, in part to reflect the benefits of the Tax Act, representing an approximate 9 percent increase on the average customer bill. The rate increase is driven by increased investment in utility plant, increased operations and maintenance expenses, and recovery of regulatory assets. The application also includes implementation of the Environmental Surcharge Mechanism to recover environmental costs not recovered in base rates, requests to establish a Distribution Capital Investment Rider to recover incremental costs of specific programs, requests to establish a FERC Transmission Cost Reconciliation Rider to recover escalating transmission costs and modification to the Profit Sharing Mechanism to increase customers' share of proceeds from the benefits of owning generation and to mitigate shareholder risks associated with that generation. An evidentiary hearing ended on March 8, 2018, and the KPSC issued an order on April 13, 2018. Major components of the Order include approval of an $8.4 million increase in base rates with a return on equity at 9.725 percent based upon a capital structure of 49 percent equity on a total allocable capitalization of approximately $650 million. The Order excludes $50 million of rate base being recovered with carrying costs elsewhere (e.g., through rider mechanisms). The Order approves the Environmental Surcharge Mechanism Rider to begin recovery in June 2018 of capital-related environmental costs, including costs related to ash and ash disposal and environmental operation and maintenance expenses formerly recovered in base rates, including expenses for environmental reagents and emission allowances. The incremental revenue from this rider will be approximately $13 million on an annualized basis. The order implements the impact of the Tax Act by lowering the income tax component of the revenue requirement, flowing back protected excess deferred income taxes (EDIT) under allowable normalization rules and unprotected EDIT over 10 years. The Order settles all matters related to the Tax Act. The Order denies requests to implement riders for certain transmission costs and distribution capital investments. Duke Energy Kentucky implemented new base rates on May 1, 2018.

Duke Energy Indiana

FERC Transmission Return on Equity Complaint

Customer groups have filed with the FERC complaints against MISO and its transmission-owning members, including Duke Energy Indiana, alleging, among other things, that the current base rate of return on equity earned by MISO transmission owners of 12.38 percent is unjust and unreasonable. The complaints claim, among other things, that the current base rate of return on equity earned by MISO transmission owners should be reduced to 8.67 percent. On January 5, 2015, the FERC issued an order accepting the MISO transmission owners' adder of 0.50 percent to the base rate of return on equity based on participation in an RTO subject to it being applied to a return on equity that is shown to be just and reasonable in the pending return on equity complaints. On December 22, 2015, the presiding FERC ALJ in the first complaint issued an Initial Decision in which the base rate of return on equity was set at 10.32 percent. On September 28, 2016, the Initial Decision in the first complaint was affirmed by FERC, but is subject to rehearing requests. On June 30, 2016, the presiding FERC ALJ in the second complaint issued an Initial Decision setting the base rate of return on equity at 9.70 percent. The Initial Decision in the second complaint is pending FERC review. On April 14, 2017, the U.S. Court of Appeals for the District of Columbia Circuit, in Emera Maine v. FERC, reversed and remanded certain aspects of the methodology employed by FERC to establish rates of return on equity. This decision may affect the outcome of the complaints against Duke Energy Indiana. Duke Energy Indiana currently believes these matters will not have a material impact on its results of operations, cash flows and financial position.

Benton County Wind Farm Dispute

On December 16, 2013, Benton County Wind Farm LLC (BCWF) filed a lawsuit against Duke Energy Indiana seeking damages for past generation losses alleging Duke Energy Indiana violated its obligations under a 2006 PPA by refusing to offer electricity to the market at negative prices. Damage claims continue to increase during times that BCWF is not dispatched. Under 2013 revised MISO market rules, Duke Energy Indiana is required to make a price offer to MISO for the power it proposes to sell into MISO markets and MISO determines whether BCWF is dispatched. Because market prices would have been negative due to increased market participation, Duke Energy Indiana determined it would not bid at negative prices in order to balance customer needs against BCWF's need to run. BCWF contends Duke Energy Indiana must bid at the lowest negative price to ensure dispatch, while Duke Energy Indiana contends it is not obligated to bid at any particular price, that it cannot ensure dispatch with any bid and that it has reasonably balanced the parties' interests. On July 6, 2015, the U.S. District Court for the Southern District of Indiana entered judgment against BCWF on all claims. BCWF appealed the decision and on December 9, 2016, the appeals court ruled in favor of BCWF. Duke Energy Indiana recorded an obligation and a regulatory asset related to the settlement amount in fourth quarter 2016. On June 30, 2017, the parties finalized a settlement agreement. Terms of the settlement included Duke Energy Indiana paying $29 million for back damages. Additionally, the parties agreed on the method by which the contract will be bid into the market in the future. The settlement amount was paid in June 2017. The IURC issued an order on September 27, 2017, approving recovery of the settlement amount through Duke Energy Indiana's fuel clause. The IURC order has been appealed to the Indiana Court of Appeals. Duke Energy Indiana cannot predict the outcome of this matter.

Piedmont

Tennessee Integrity Management Rider Filing

In November 2017, Piedmont filed a petition with the TPUC under the IMR mechanism to collect an additional $3.3 million in annual revenues, effective January 2018, based on the eligible capital investments for integrity and safety projects through October 31, 2017. In January 2018, Piedmont filed an amended computation under the IMR mechanism, revising the proposed increase in annual revenues to approximately $0.4 million based on the decrease in the corporate federal income tax rate effective January 1, 2018. A hearing on this matter was held on April 9, 2018, and a decision is expected mid-2018. Piedmont cannot predict the outcome of this matter.

OTHER REGULATORY MATTERS

Atlantic Coast Pipeline, LLC

On September 2, 2014, Duke Energy, Dominion Resources (Dominion), Piedmont and Southern Company Gas announced the formation of Atlantic Coast Pipeline, LLC (ACP) to build and own the proposed Atlantic Coast Pipeline (ACP pipeline), an approximately 600-mile interstate natural gas pipeline running from West Virginia to North Carolina. The ACP pipeline is designed to meet, in part, the needs identified by Duke Energy Carolinas, Duke Energy Progress and Piedmont. Dominion will build and operate the ACP pipeline and holds a leading ownership percentage in ACP of 48 percent. Duke Energy owns a 47 percent interest through its Gas Utilities and Infrastructure segment. Southern Company Gas maintains a 5 percent interest. See Note 11 for additional information related to Duke Energy's ownership interest.

Duke Energy Carolinas, Duke Energy Progress and Piedmont, among others, will be customers of the pipeline. Purchases will be made under several 20-year supply contracts, subject to state regulatory approval. On September 18, 2015, ACP filed an application with the FERC requesting a CPCN authorizing ACP to construct the pipeline. ACP executed a construction agreement in September 2016. ACP also requested approval of an open access tariff and the precedent agreements it entered into with future pipeline customers. In December 2016, FERC issued a draft Environmental Impact Statement (EIS) indicating that the proposed pipeline would not cause significant harm to the environment or protected populations. The FERC issued the final EIS in July 2017. On October 13, 2017, FERC issued an order approving the CPCN, subject to conditions. On October 16, 2017, ACP accepted the FERC order subject to reserving its right to file a request for rehearing or clarification on a timely basis. On November 9, 2017, ACP filed a request for rehearing on several limited issues. On December 12, 2017, ACP filed an answer to intervenors’ request for rehearing of the certificate order and for stay of the certificate order.

In December 2017, West Virginia issued a waiver of the state water quality permit in reliance on the U.S. Army Corps of Engineers national water quality permit and Virginia issued a conditional water quality permit subject to completion of additional studies and stormwater plans. In 2018, the FERC issued a series of Partial Notices to Proceed, which authorized the project to begin limited construction-related activities along the pipeline route, including supply header and compressors. North Carolina issued the state water quality permit in January 2018. The project remains subject to other pending federal and state approvals, which will allow full construction activities to begin. The ACP pipeline project has a targeted in-service date of late 2019.

Due to delays in obtaining the required permits to commence construction and the conditions imposed upon the project by the permits, ACP's project manager estimates the project's pipeline development costs have increased from a range of $5.0 billion to $5.5 billion to a range of $6.0 billion and $6.5 billion, excluding financing costs. Project construction activities, schedule and final costs are still subject to uncertainty due to potential additional permitting delays, construction productivity and other conditions and risks which could result in potential higher project costs and a potential delay in the targeted in-service date.

Sabal Trail Transmission, LLC

On May 4, 2015, Duke Energy acquired a 7.5 percent ownership interest in Sabal Trail from Spectra Energy Partners, LP, a master limited partnership, formed by Enbridge Inc. (formerly Spectra Energy Corp.). Spectra Energy Partners, LP holds a 50 percent ownership interest in Sabal Trail and NextEra Energy has a 42.5 percent ownership interest. Sabal Trail is a joint venture to construct a 515-mile natural gas pipeline (Sabal Trail pipeline) to transport natural gas to Florida. Total estimated project costs are approximately $3.2 billion. The Sabal Trail pipeline traverses Alabama, Georgia and Florida. The primary customers of the Sabal Trail pipeline, Duke Energy Florida and Florida Power & Light Company (FP&L), have each contracted to buy pipeline capacity for 25-year initial terms. See Note 11 for additional information related to Duke Energy's ownership interest.

On February 3, 2016, the FERC issued an order granting the request for a CPCN to construct and operate the pipeline. The Sabal Trail pipeline received other required regulatory approvals and the Phase 1 mainline was placed in service in July 2017. On October 12, 2017, Sabal Trail filed a request with FERC to place in service a lateral line to Duke Energy Florida's Citrus County Combined Cycle facility. This request is required to support commissioning and testing activities at the facility. On March 16, 2018, FERC approved the Citrus lateral and it was placed in service.

On September 21, 2016, intervenors filed an appeal of FERC's CPCN orders to the U.S. Court of Appeals for the District of Columbia Circuit (D.C. Circuit Court of Appeals). On August 22, 2017, the appeals court ruled against FERC in the case for failing to include enough information on the impact of greenhouse-gas emissions carried by the pipeline, vacated the CPCN order and remanded the case to FERC. In response to the August 2017 court decision, the FERC issued a draft Supplemental Environmental Impact Statement (SEIS) on September 27, 2017. On October 6, 2017, FERC and a group of industry intervenors, including Sabal Trail and Duke Energy Florida, filed separate petitions with the D.C. Circuit Court of Appeals requesting rehearing regarding the court's decision to vacate the CPCN order. On January 31, 2018, the D.C. Circuit Court of Appeals denied the requests for rehearing. On February 2, 2018, Sabal Trail filed a request with FERC for expedited issuance of its order on remand and reissuance of the CPCN. In the alternative, the pipeline requested that FERC issue a temporary emergency CPCN to allow for continued operations. On February 5, 2018, FERC issued the final SEIS but did not issue the order on remand. On February 6, 2018, FERC and the intervenors in this case each filed motions for stay with the D.C. Circuit Court to stay the court's mandate. The February 6, 2018, motions automatically stay the issuance of the court’s mandate until the later of seven days after the court denies the motions or the expiration of any stay granted by the court. On March 7, 2018, the D.C. Circuit Court of Appeals granted Sabal Trail’s stay request. On March 14, 2018, FERC issued its final order on remand.

Constitution Pipeline Company, LLC

Duke Energy owns a 24 percent ownership interest in Constitution, which is accounted for as an equity method investment. Constitution is a natural gas pipeline project slated to transport natural gas supplies from the Marcellus supply region in northern Pennsylvania to major northeastern markets. The pipeline will be constructed and operated by Williams Partners L.P., which has a 41 percent ownership share. The remaining interest is held by Cabot Oil and Gas Corporation and WGL Holdings, Inc. Before the permitting delays discussed below, Duke Energy's total anticipated contributions were approximately $229 million. As a result of the permitting delays and project uncertainty, total anticipated contributions by Duke Energy can no longer be reasonably estimated. Since April 2016, with the actions of the New York State Department of Environmental Conservation (NYSDEC), Constitution stopped construction and discontinued capitalization of future development costs until the project's uncertainty is resolved.

In December 2014, Constitution received approval from the FERC to construct and operate the proposed pipeline. However, on April 22, 2016, the NYSDEC denied Constitution’s application for a necessary water quality certification for the New York portion of the Constitution pipeline. Constitution filed legal actions in the U.S. Court of Appeals for the Second Circuit (U.S. Court of Appeals) challenging the legality and appropriateness of the NYSDEC’s decision and on August 18, 2017, the petition was denied in part and dismissed in part. In September 2017, Constitution filed a petition for a rehearing of portions of the decision unrelated to the water quality certification, which was denied by the U.S. Court of Appeals. In January 2018, Constitution petitioned the Supreme Court of the United States to review the U.S. Court of Appeals decision, and on April 30, 2018, the Supreme Court denied Constitution's petition. In October 2017, Constitution filed a petition for declaratory order requesting FERC to find that the NYSDEC waived its rights to issue a Section 401 water quality certification by not acting on Constitution's application within a reasonable period of time as required by statute. This petition was based on precedent established by another pipeline’s successful petition with FERC following a District of Columbia Circuit Court ruling. On January 11, 2018, FERC denied Constitution's petition. In February 2018, Constitution filed a rehearing request with FERC of its finding that the NYSDEC did not waive the Section 401 certification requirement. Constitution is currently unable to approximate an in-service date for the project due to the NYSDEC's denial of the water quality certification. The Constitution partners remain committed to the project and are evaluating next steps to move the project forward. Duke Energy cannot predict the outcome of this matter.

During the three months endedMarch 31, 2018, Duke Energy recorded an other-than-temporary impairment (OTTI) of $55 million within Equity in (losses) earnings of unconsolidated affiliates on Duke Energy's Condensed Consolidated Statements of Income. The charge represents the excess carrying value over the estimated fair value of the project, which was based on a Level 3 Fair Value measurement that was determined from the income approach using discounted cash flows. The impairment was primarily due to the recent actions taken by the courts and regulators to uphold the NYSDEC's denial of the certification and uncertainty associated with the remaining legal and regulatory challenges.

See Note 11 for additional information related to ownership interest and carrying value of the investment.

Potential Coal Plant Retirements

The Subsidiary Registrants periodically file Integrated Resource Plans (IRP) with their state regulatory commissions. The IRPs provide a view of forecasted energy needs over a long term (10 to 20 years) and options being considered to meet those needs. Recent IRPs filed by the Subsidiary Registrants included planning assumptions to potentially retire certain coal-fired generating facilities in Florida and Indiana earlier than their current estimated useful lives primarily because facilities do not have the requisite emission control equipment to meet EPA regulations recently approved or proposed.

The table below contains the net carrying value of generating facilities planned for retirement or included in recent IRPs as evaluated for potential retirement due to a lack of requisite environmental control equipment. Dollar amounts in the table below are included in Net property, plant and equipment on the Condensed Consolidated Balance Sheets as of March 31, 2018, and exclude capitalized asset retirement costs.

		Remaining Net
	Capacity	Book Value
	(in MW)	(in millions)
Duke Energy Carolinas
Allen Steam Station Units 1-3(a)	585	$	161
Progress Energy and Duke Energy Florida
Crystal River Units 1 and 2(b)	873	104
Duke Energy Indiana
Gallagher Units 2 and 4(c)	280	126
Total Duke Energy	1,738	$	391

(a) Duke Energy Carolinas will retire Allen Steam Station Units 1 through 3 by December 31, 2024, as part of the resolution of a lawsuit involving alleged New Source Review violations.

(b) Duke Energy Florida expects to retire these coal units by the end of 2018 to comply with environmental regulations.

(c) Duke Energy Indiana committed to either retire or stop burning coal at Gallagher Units 2 and 4 by December 31, 2022, as part of the settlement of Edwardsport IGCC matters.

Refer to the "Western Carolinas Modernization Plan" discussion above for details of Duke Energy Progress' planned retirements.

XML

Commitments and Contingencies

3 Months Ended

Mar. 31, 2018

Commitments and Contingencies Disclosure [Abstract]

Commitments And Contingencies

COMMITMENTS AND CONTINGENCIES

ENVIRONMENTAL

The Duke Energy Registrants are subject to federal, state and local regulations regarding air and water quality, hazardous and solid waste disposal and other environmental matters. These regulations can be changed from time to time, imposing new obligations on the Duke Energy Registrants. The following environmental matters impact all of the Duke Energy Registrants.

Remediation Activities

In addition to asset retirement obligations (ARO) recorded as a result of various environmental regulations, the Duke Energy Registrants are responsible for environmental remediation at various sites. These include certain properties that are part of ongoing operations and sites formerly owned or used by Duke Energy entities. These sites are in various stages of investigation, remediation and monitoring. Managed in conjunction with relevant federal, state and local agencies, remediation activities vary based upon site conditions and location, remediation requirements, complexity and sharing of responsibility. If remediation activities involve joint and several liability provisions, strict liability, or cost recovery or contribution actions, the Duke Energy Registrants could potentially be held responsible for environmental impacts caused by other potentially responsible parties and may also benefit from insurance policies or contractual indemnities that cover some or all cleanup costs. Liabilities are recorded when losses become probable and are reasonably estimable. The total costs that may be incurred cannot be estimated because the extent of environmental impact, allocation among potentially responsible parties, remediation alternatives and/or regulatory decisions have not yet been determined at all sites. Additional costs associated with remediation activities are likely to be incurred in the future and could be significant. Costs are typically expensed as Operation, maintenance and other on the Condensed Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable.

The following tables contain information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Accounts Payable within Current Liabilities and Other within Other Noncurrent Liabilities on the Condensed Consolidated Balance Sheets.

	Three Months Ended March 31, 2018
				Duke					Duke			Duke			Duke			Duke
	Duke			Energy		Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas		Energy			Progress			Florida			Ohio			Indiana		Piedmont
Balance at beginning of period	$	81		$	10	$	15		$	3		$	12		$	47		$	5	$	2
Provisions/adjustments	4			1		3			1			1			—			1		—
Cash reductions	(5		)	—		(2		)	(1		)	(1		)	(3		)	—		—
Balance at end of period	$	80		$	11	$	16		$	3		$	12		$	44		$	6	$	2

	Three Months Ended March 31, 2017
				Duke					Duke		Duke			Duke			Duke
	Duke			Energy		Progress			Energy		Energy			Energy			Energy
(in millions)	Energy			Carolinas		Energy			Progress		Florida			Ohio			Indiana			Piedmont
Balance at beginning of period	$	98		$	10	$	18		$	3	$	14		$	59		$	10		$	1
Provisions/adjustments	6			1		—			—		1			4			(1		)	1
Cash reductions	(6		)	—		(1		)	—		(1		)	(4		)	—			—
Balance at end of period	$	98		$	11	$	17		$	3	$	14		$	59		$	9		$	2

Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are not material except as presented in the table below.

(in millions)
Duke Energy	$	57
Duke Energy Carolinas	19
Duke Energy Ohio	30
Piedmont	2

LITIGATION

Duke Energy Carolinas and Duke Energy Progress

Coal Ash Insurance Coverage Litigation

In March 2017, Duke Energy Carolinas and Duke Energy Progress filed a civil action in North Carolina Superior Court against various insurance providers. The lawsuit seeks payment for coal ash-related liabilities covered by third-party liability insurance policies. The insurance policies were issued between 1971 and 1986 and provide third-party liability insurance for property damage. The civil action seeks damages for breach of contract and indemnification for costs arising from the Coal Ash Act and the EPA CCR rule at 15 coal-fired plants in North Carolina and South Carolina. The parties are engaged in discovery. Duke Energy Carolinas and Duke Energy Progress cannot predict the outcome of this matter.

NCDEQ State Enforcement Actions

In the first quarter of 2013, the Southern Environmental Law Center (SELC) sent notices of intent to sue Duke Energy Carolinas and Duke Energy Progress related to alleged Clean Water Act (CWA) violations from coal ash basins at two of their coal-fired power plants in North Carolina. The NCDEQ filed enforcement actions against Duke Energy Carolinas and Duke Energy Progress alleging violations of water discharge permits and North Carolina groundwater standards. The cases have been consolidated and are being heard before a single judge in the North Carolina Superior Court.

On August 16, 2013, the NCDEQ filed an enforcement action against Duke Energy Carolinas and Duke Energy Progress related to their remaining plants in North Carolina, alleging violations of the CWA and violations of the North Carolina groundwater standards. Both of these cases have been assigned to the judge handling the enforcement actions discussed above. SELC is representing several environmental groups who have been permitted to intervene in these cases.

The court issued orders in 2016 granting Motions for Partial Summary Judgment for seven of the 14 North Carolina plants named in the enforcement actions. On February 13, 2017, the court issued an order denying motions for partial summary judgment brought by both the environmental groups and Duke Energy Carolinas and Duke Energy Progress for the remaining seven plants. On March 15, 2017, Duke Energy Carolinas and Duke Energy Progress filed a Notice of Appeal to challenge the trial court’s order. The parties were unable to reach an agreement at mediation in April 2017. The parties submitted briefs to the court on remaining issues to be tried and a ruling is pending. On August 22, 2017, Duke Energy Carolinas and Duke Energy Progress filed a Petition for Discretionary Review, requesting the North Carolina Supreme Court to accept the appeal. On August 24, 2017, SELC filed a motion to dismiss the appeal. Duke Energy Carolinas' and Duke Energy Progress’ opening appellate briefs were filed on October 12, 2017, and briefing is now complete. Argument was held on February 8, 2018.

It is not possible to predict any liability or estimate any damages Duke Energy Carolinas or Duke Energy Progress might incur in connection with these matters.

Federal Citizens Suits

On June 13, 2016, the Roanoke River Basin Association (RRBA) filed a federal citizen suit in the Middle District of North Carolina alleging unpermitted discharges to surface water and groundwater violations at the Mayo Plant. On August 19, 2016, Duke Energy Progress filed a Motion to Dismiss. On April 26, 2017, the court entered an order dismissing four of the claims in the federal citizen suit. Two claims relating to alleged violations of National Pollutant Discharge Elimination System (NPDES) permit provisions survived the motion to dismiss, and Duke Energy Progress filed its response on May 10, 2017. Duke Energy Progress and RRBA each filed motions for summary judgment on March 23, 2018.

On May 16, 2017, RRBA filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina, which asserts two claims relating to alleged violations of NPDES permit provisions at the Roxboro plant and one claim relating to the use of nearby water bodies. Duke Energy Progress and RRBA each filed motions for summary judgment on April 17, 2018.

On May 8, 2018, on motion from Duke Energy Progress, the Court ordered trial in both of the above matters to be consolidated and has set a trial date for December 3, 2018.

On June 20, 2017, RRBA filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina challenging the closure plans at the Mayo Plant under the EPA CCR Rule. Duke Energy Progress filed a motion to dismiss, which was granted by the court on March 30, 2018. RRBA had until April 30, 2018 to file an appeal to the Fourth Circuit but did not do so.

On August 2, 2017, RRBA filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina challenging the closure plans at the Roxboro Plant under the EPA CCR Rule. Duke Energy Progress filed a motion to dismiss on October 2, 2017.

On December 6, 2017, various parties filed a federal citizen suit in the U.S. District Court for the Middle District of North Carolina for alleged violations at Duke Energy Carolinas' Belews Creek Steam Station (Belews Creek) under the CWA. Duke Energy Carolinas filed a motion to dismiss on February 5, 2018.

It is not possible to predict whether Duke Energy Carolinas or Duke Energy Progress will incur any liability or to estimate the damages, if any, they might incur in connection with these matters.

Groundwater Contamination Claims

Beginning in May 2015, a number of residents living in the vicinity of the North Carolina facilities with ash basins received letters from the NCDEQ advising them not to drink water from the private wells on their land tested by the NCDEQ as the samples were found to have certain substances at levels higher than the criteria set by the North Carolina Department of Health and Human Services (DHHS). Results of Comprehensive Site Assessments testing performed by Duke Energy under the Coal Ash Act have been consistent with historical data provided to state regulators over many years. The DHHS and NCDEQ sent follow-up letters on October 15, 2015, to residents near coal ash basins who had their wells tested, stating that private well samplings at a considerable distance from coal ash basins, as well as some municipal water supplies, contain similar levels of vanadium and hexavalent chromium, which led investigators to believe these constituents are naturally occurring. In March 2016, DHHS rescinded the advisories.

Duke Energy Carolinas and Duke Energy Progress have received formal demand letters from residents near Duke Energy Carolinas' and Duke Energy Progress' coal ash basins. The residents claim damages for nuisance and diminution in property value, among other things. The parties held three days of mediation discussions that ended at an impasse. On January 6, 2017, Duke Energy Carolinas and Duke Energy Progress received the plaintiffs' notice of their intent to file suits should the matter not settle. The NCDEQ preliminarily approved Duke Energy’s permanent water solution plans on January 13, 2017, and as a result shortly thereafter, Duke Energy issued a press release, providing additional details regarding the homeowner compensation package. This package consists of three components: (i) a $5,000 goodwill payment to each eligible well owner to support the transition to a new water supply, (ii) where a public water supply is available and selected by the eligible well owner, a stipend to cover 25 years of water bills and (iii) the Property Value Protection Plan. The Property Value Protection Plan is a program offered by Duke Energy designed to guarantee eligible plant neighbors the fair market value of their residential property should they decide to sell their property during the time that the plan is offered. Duke Energy Carolinas and Duke Energy Progress have recognized reserves of $16 million and $3 million, respectively.

On August 23, 2017, a class-action suit was filed in Wake County Superior Court, North Carolina, against Duke Energy Carolinas and Duke Energy Progress on behalf of certain property owners living near coal ash impoundments at Allen, Asheville, Belews Creek, Buck, Cliffside, Lee, Marshall, Mayo and Roxboro. The class is defined as those who are “well-eligible” under the Coal Ash Act or those to whom Duke Energy has promised a permanent replacement water supply and seeks declaratory and injunctive relief, along with compensatory damages. Plaintiffs allege that Duke Energy’s improper maintenance of coal ash impoundments caused harm, particularly through groundwater contamination. Despite NCDEQ’s preliminary approval, Plaintiffs contend that Duke Energy’s proposed permanent water solutions plan fails to comply with the Coal Ash Act. On September 28, 2017, Duke Energy Carolinas and Duke Energy Progress filed a Motion to Dismiss and Motion to Strike the class designation. The parties entered into a Settlement Agreement on January 24, 2018, which resulted in the dismissal of the underlying class action on January 25, 2018.

On September 14, 2017, a complaint was filed against Duke Energy Progress in New Hanover County Superior Court by a group of homeowners residing approximately one mile from Duke Energy Progress' Sutton Steam Plant (Sutton). The homeowners allege that coal ash constituents have been migrating from ash impoundments at Sutton into their groundwater for decades and that in 2015, Duke Energy Progress discovered these releases of coal ash, but failed to notify any officials or neighbors and failed to take remedial action. The homeowners claim unspecified physical and mental injuries as a result of consuming their well water and seek actual damages for personal injury, medical monitoring and punitive damages. On March 6, 2018, Plaintiffs' counsel voluntarily dismissed the action without prejudice.

It is not possible to estimate the maximum exposure of loss, if any, that may occur in connection with future claims that might be made by these residents.

Asbestos-related Injuries and Damages Claims

Duke Energy Carolinas has experienced numerous claims for indemnification and medical cost reimbursement related to asbestos exposure. These claims relate to damages for bodily injuries alleged to have arisen from exposure to or use of asbestos in connection with construction and maintenance activities conducted on its electric generation plants prior to 1985. As of March 31, 2018, there were 143 asserted claims for non-malignant cases with cumulative relief sought of up to $37 million, and 58 asserted claims for malignant cases with cumulative relief sought of up to $19 million. Based on Duke Energy Carolinas’ experience, it is expected that the ultimate resolution of most of these claims likely will be less than the amount claimed.

Duke Energy Carolinas has recognized asbestos-related reserves of $487 million at March 31, 2018, and $489 million at December 31, 2017. These reserves are classified in Other within Other Noncurrent Liabilities and Other within Current Liabilities on the Condensed Consolidated Balance Sheets. These reserves are based upon the minimum amount of the range of loss for current and future asbestos claims through 2037, are recorded on an undiscounted basis and incorporate anticipated inflation. In light of the uncertainties inherent in a longer-term forecast, management does not believe they can reasonably estimate the indemnity and medical costs that might be incurred after 2037 related to such potential claims. It is possible Duke Energy Carolinas may incur asbestos liabilities in excess of the recorded reserves.

Duke Energy Carolinas has third-party insurance to cover certain losses related to asbestos-related injuries and damages above an aggregate self-insured retention. Duke Energy Carolinas’ cumulative payments began to exceed the self-insurance retention in 2008. Future payments up to the policy limit will be reimbursed by the third-party insurance carrier. The insurance policy limit for potential future insurance recoveries indemnification and medical cost claim payments is $797 million in excess of the self-insured retention. Receivables for insurance recoveries were $585 million at March 31, 2018, and December 31, 2017. These amounts are classified in Other within Other Noncurrent Assets and Receivables within Current Assets on the Condensed Consolidated Balance Sheets. Duke Energy Carolinas is not aware of any uncertainties regarding the legal sufficiency of insurance claims. Duke Energy Carolinas believes the insurance recovery asset is probable of recovery as the insurance carrier continues to have a strong financial strength rating.

Duke Energy Progress and Duke Energy Florida

Spent Nuclear Fuel Matters

On October 16, 2014, Duke Energy Progress and Duke Energy Florida sued the U.S. in the U.S. Court of Federal Claims. The lawsuit claimed the Department of Energy breached a contract in failing to accept spent nuclear fuel under the Nuclear Waste Policy Act of 1982 and asserted damages for the cost of on-site storage. Duke Energy Progress and Duke Energy Florida asserted damages for the period January 1, 2011, through December 31, 2013, of $48 million and $25 million, respectively. On November 17, 2017, the Court awarded Duke Energy Progress and Duke Energy Florida $48 million and $21 million, respectively, subject to appeal. No appeals were filed and Duke Energy Progress and Duke Energy Florida recognized the recoveries in the first quarter of 2018. Claims for all periods through 2013 have been resolved. Additional claims will be filed in 2018.

Duke Energy Progress

Gypsum Supply Agreement Matter

On June 30, 2017, CertainTeed Gypsum NC, Inc. (CertainTeed) filed a declaratory judgment action against Duke Energy Progress in the North Carolina Business Court relating to a gypsum supply agreement. In its complaint, CertainTeed sought an order from the court declaring that the minimum amount of gypsum Duke Energy Progress must provide to CertainTeed under the supply agreement is 50,000 tons per month through 2029. On January 29, 2018, CertainTeed filed a request to amend its Complaint and seek a preliminary injunction requiring Duke Energy Progress to provide 50,000 tons of gypsum per month through the trial date. In advance of the hearing on the Motion for Preliminary Injunction, the parties reached an agreement under which Duke Energy Progress would deliver 50,000 tons of gypsum per month through June 2018. If the Court determines that Duke Energy Progress was not obligated to provide that amount per month, CertainTeed will reimburse Duke Energy Progress. Discovery is currently underway and trial is set for July 2018. If Duke Energy Progress does not prevail at trial, Duke Energy Progress will either have to purchase additional gypsum on the open market to fulfill its contractual obligation through 2029 or pay some amount of liquidated damages. Duke Energy Progress cannot predict the outcome of this matter.

Duke Energy Florida

Class Action Lawsuit

On February 22, 2016, a lawsuit was filed in the U.S. District Court for the Southern District of Florida on behalf of a putative class of Duke Energy Florida and FP&L’s customers in Florida. The suit alleges the State of Florida’s nuclear power plant cost recovery statutes (NCRS) are unconstitutional and pre-empted by federal law. Plaintiffs claim they are entitled to repayment of all money paid by customers of Duke Energy Florida and FP&L as a result of the NCRS, as well as an injunction against any future charges under those statutes. The constitutionality of the NCRS has been challenged unsuccessfully in a number of prior cases on alternative grounds. Duke Energy Florida and FP&L filed motions to dismiss the complaint on May 5, 2016. On September 21, 2016, the Court granted the motions to dismiss with prejudice. Plaintiffs filed a motion for reconsideration, which was denied. On January 4, 2017, plaintiffs filed a notice of appeal to the Eleventh Circuit U.S. Court of Appeals. The appeal, which has been fully briefed, was heard on August 22, 2017, and a decision is pending. Duke Energy Florida cannot predict the outcome of this appeal.

Westinghouse Contract Litigation

On March 28, 2014, Duke Energy Florida filed a lawsuit against Westinghouse in the U.S. District Court for the Western District of North Carolina. The lawsuit seeks recovery of $54 million in milestone payments in excess of work performed under an EPC for Levy as well as a determination by the court of the amounts due to Westinghouse as a result of the termination of an EPC contract. Duke Energy Florida recognized an exit obligation as a result of the termination of the EPC. On March 31, 2014, Westinghouse filed a separate lawsuit against Duke Energy Florida in U.S. District Court for the Western District of Pennsylvania alleging damages under the same EPC contract in excess of $510 million for engineering and design work, costs to end supplier contracts and an alleged termination fee. On June 9, 2014, the judge in the North Carolina case ruled that the litigation would proceed in the Western District of North Carolina.

On July 11, 2016, Duke Energy Florida and Westinghouse filed separate Motions for Summary Judgment. On September 29, 2016, the court issued its ruling, granting Westinghouse a $30 million termination fee claim and dismissing Duke Energy Florida's $54 million refund claim. Westinghouse's claim for termination costs continued to trial. Following a trial on the matter, the court issued an order in December 2016 denying Westinghouse’s claim for termination costs and reaffirming its earlier ruling in favor of Westinghouse on the $30 million termination fee. Judgment was entered against Duke Energy Florida in the amount of approximately $34 million, which includes prejudgment interest. Westinghouse has appealed the trial court's order to the U.S. Court of Appeals for the Fourth Circuit (Fourth Circuit Court) and Duke Energy Florida has cross-appealed.

On March 29, 2017, Westinghouse filed Chapter 11 bankruptcy in the Southern District of New York, which automatically stayed the appeal. On May 23, 2017, the bankruptcy court entered an order lifting the stay with respect to the appeal. Briefing of the appeal concluded on October 20, 2017. Westinghouse and Duke Energy Florida executed a settlement agreement resolving this matter on April 5, 2018, which has been filed with the bankruptcy court for approval. The settlement provides that the appeal will be dismissed and Duke Energy Florida will pay the judgment amount of approximately $34 million. This reserve is classified in Other within Other Noncurrent Liabilities on the Condensed Consolidated Balance Sheet. In light of the settlement, the Fourth Circuit Court agreed to stay the appeal pending bankruptcy court approval of the settlement. Duke Energy cannot predict the ultimate outcome of this appeal or the bankruptcy court's approval of the pending settlement.

MGP Cost Recovery Action

On December 30, 2011, Duke Energy Florida filed a lawsuit against FirstEnergy Corp. (FirstEnergy) to recover investigation and remediation costs incurred by Duke Energy Florida in connection with the restoration of two former MGP sites in Florida. Duke Energy Florida alleged that FirstEnergy, as the successor to Associated Gas & Electric Co., owes past and future contribution and response costs of up to $43 million for the investigation and remediation of MGP sites. On December 6, 2016, the trial court entered judgment against Duke Energy Florida in the case. In January 2017, Duke Energy Florida appealed the decision to the U.S. Court of Appeals for the 6th Circuit, which affirmed the trial court's ruling on April 10, 2018. Duke Energy Florida cannot predict the outcome of this appeal.

Other Litigation and Legal Proceedings

The Duke Energy Registrants are involved in other legal, tax and regulatory proceedings arising in the ordinary course of business, some of which involve significant amounts. The Duke Energy Registrants believe the final disposition of these proceedings will not have a material effect on their results of operations, cash flows or financial position.

The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters, excluding asbestos-related reserves and the exit obligation related to the termination of an EPC contract discussed above. Reserves are classified on the Condensed Consolidated Balance Sheets in Other within Other Noncurrent Liabilities and Accounts payable and Other within Current Liabilities. The reasonably possible range of loss in excess of recorded reserves is not material, other than as described above.

(in millions)	March 31, 2018		December 31, 2017
Reserves for Legal Matters
Duke Energy	$	74	$	88
Duke Energy Carolinas	20		30
Progress Energy	51		55
Duke Energy Progress	10		13
Duke Energy Florida	24		24
Piedmont	2		2

OTHER COMMITMENTS AND CONTINGENCIES

General

As part of their normal business, the Duke Energy Registrants are party to various financial guarantees, performance guarantees and other contractual commitments to extend guarantees of credit and other assistance to various subsidiaries, investees and other third parties. These guarantees involve elements of performance and credit risk, which are not fully recognized on the Condensed Consolidated Balance Sheets and have unlimited maximum potential payments. However, the Duke Energy Registrants do not believe these guarantees will have a material effect on their results of operations, cash flows or financial position.

In addition, the Duke Energy Registrants enter into various fixed-price, noncancelable commitments to purchase or sell power or natural gas, take-or-pay arrangements, transportation, or throughput agreements and other contracts that may or may not be recognized on their respective Condensed Consolidated Balance Sheets. Some of these arrangements may be recognized at fair value on their respective Condensed Consolidated Balance Sheets if such contracts meet the definition of a derivative and the normal purchase/normal sale (NPNS) exception does not apply. In most cases, the Duke Energy Registrants’ purchase obligation contracts contain provisions for price adjustments, minimum purchase levels and other financial commitments.

XML

Debt and Credit Facilities

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Debt And Credit Facilities

DEBT AND CREDIT FACILITIES

SUMMARY OF SIGNIFICANT DEBT ISSUANCES

The following table summarizes significant debt issuances (in millions).

				Three Months Ended March 31, 2018
						Duke		Duke
	Maturity	Interest		Duke		Energy		Energy
Issuance Date	Date	Rate		Energy		(Parent)		Carolinas
Unsecured Debt
March 2018(a)	April 2025	3.950	%	$	250	$	250	$	—
First Mortgage Bonds
March 2018(b)	March 2023	3.050	%	500		—		500
March 2018(b)	March 2048	3.950	%	500		—		500
Total issuances				$	1,250	$	250	$	1,000

(a) Debt issued to pay down short-term debt.

(b) Debt issued to repay at maturity a $300 million first mortgage bond due April 2018, pay down intercompany short-term debt and for general corporate purposes.

CURRENT MATURITIES OF LONG-TERM DEBT

The following table shows the significant components of Current Maturities of Long-Term Debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings.

(in millions)	Maturity Date	Interest Rate			March 31, 2018
Unsecured Debt
Duke Energy (Parent)	June 2018	6.250	%		$	250
Duke Energy (Parent)	June 2018	2.100	%		500
Piedmont	December 2018	2.821	%	(b)	250
Progress Energy	March 2019	7.050	%		450
First Mortgage Bonds
Duke Energy Carolinas	April 2018	5.100	%		300
Duke Energy Florida	June 2018	5.650	%		500
Duke Energy Carolinas	November 2018	7.000	%		500
Duke Energy Progress	January 2019	5.300	%		600
Other(a)					601
Current maturities of long-term debt					$	3,951

(a)    Includes capital lease obligations, amortizing debt and small bullet maturities.

(b)    Debt issuance has a floating interest rate.

AVAILABLE CREDIT FACILITIES

Master Credit Facility

In January 2018, Duke Energy extended the termination date of substantially all of its existing $8 billion Master Credit Facility capacity from March 16, 2022 to March 16, 2023. In May 2018, Duke Energy completed the extension process with 100 percent of all commitments to the Master Credit Facility extending to March 16, 2023. The Duke Energy Registrants, excluding Progress Energy (Parent), have borrowing capacity under the Master Credit Facility up to a specified sublimit for each borrower. Duke Energy has the unilateral ability at any time to increase or decrease the borrowing sublimits of each borrower, subject to a maximum sublimit for each borrower. The amount available under the Master Credit Facility has been reduced to backstop issuances of commercial paper, certain letters of credit and variable-rate demand tax-exempt bonds that may be put to the Duke Energy Registrants at the option of the holder. Duke Energy Carolinas and Duke Energy Progress are also required to each maintain $250 million of available capacity under the Master Credit Facility as security to meet obligations under plea agreements reached with the U.S. Department of Justice in 2015 related to violations at North Carolina facilities with ash basins. The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility.

	March 31, 2018
				Duke			Duke			Duke			Duke			Duke			Duke
	Duke			Energy			Energy			Energy			Energy			Energy			Energy
(in millions)	Energy			(Parent)			Carolinas			Progress			Florida			Ohio			Indiana			Piedmont
Facility size(a)	$	8,000		$	2,650		$	1,550		$	1,250		$	800		$	450		$	600		$	700
Reduction to backstop issuances
Commercial paper(b)	(2,602		)	(1,281		)	(340		)	(464		)	—			(140		)	(282		)	(95		)
Outstanding letters of credit	(59		)	(50		)	(4		)	(2		)	(1		)	—			—			(2		)
Tax-exempt bonds	(81		)	—			—			—			—			—			(81		)	—
Coal ash set-aside	(500		)	—			(250		)	(250		)	—			—			—			—
Available capacity under the Master Credit Facility	$	4,758		$	1,319		$	956		$	534		$	799		$	310		$	237		$	603

(a) Represents the sublimit of each borrower.

(b) Duke Energy issued $625 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies on the Condensed Consolidated Balance Sheets.

Three-Year Revolving Credit Facility

Duke Energy (Parent) has a $1.0 billion revolving credit facility (the Three Year Revolver) through June 2020. As of March 31, 2018, $500 million has been drawn under the Three Year Revolver. This balance is classified as Long-Term Debt on Duke Energy's Condensed Consolidated Balance Sheets. Any undrawn commitments can be drawn, and borrowings can be prepaid, at any time throughout the term of the facility. The terms and conditions of the Three Year Revolver are generally consistent with those governing Duke Energy's Master Credit Facility.

XML

Goodwill

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill

GOODWILL

Duke Energy

The following table presents the goodwill by reportable operating segment included on Duke Energy's Condensed Consolidated Balance Sheets at March 31, 2018, and December 31, 2017.

	Electric Utilities		Gas Utilities		Commercial
(in millions)	and Infrastructure		and Infrastructure		Renewables			Total
Goodwill balance	$	17,379	$	1,924	$	122		$	19,425
Accumulated impairment charges	—		—		(29		)	(29		)
Goodwill, adjusted for accumulated impairment charges	$	17,379	$	1,924	$	93		$	19,396

Duke Energy Ohio

Duke Energy Ohio's Goodwill balance of $920 million, allocated $596 million to Electric Utilities and Infrastructure and $324 million to Gas Utilities and Infrastructure, is presented net of accumulated impairment charges of $216 million on the Condensed Consolidated Balance Sheets at March 31, 2018, and December 31, 2017.

Progress Energy

Progress Energy's Goodwill is included in the Electric Utilities and Infrastructure operating segment and there are no accumulated impairment charges.

Piedmont

Piedmont's Goodwill is included in the Gas Utilities and Infrastructure operating segment and there are no accumulated impairment charges.

XML

Related Party Transactions

3 Months Ended

Mar. 31, 2018

Related Party Transactions [Abstract]

Related Party Transactions

RELATED PARTY TRANSACTIONS

The Subsidiary Registrants engage in related party transactions in accordance with applicable state and federal commission regulations. Refer to the Condensed Consolidated Balance Sheets of the Subsidiary Registrants for balances due to or due from related parties. Material amounts related to transactions with related parties included on the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table.

	Three Months Ended March 31,
(in millions)	2018		2017
Duke Energy Carolinas
Corporate governance and shared service expenses(a)	$	220	$	221
Indemnification coverages(b)	6		6
JDA revenue(c)	34		16
JDA expense(c)	54		31
Intercompany natural gas purchases(d)	4		1
Progress Energy
Corporate governance and shared service expenses(a)	$	191	$	170
Indemnification coverages(b)	8		10
JDA revenue(c)	54		31
JDA expense(c)	34		16
Intercompany natural gas purchases(d)	19		19
Duke Energy Progress
Corporate governance and shared service expenses(a)	$	118	$	100
Indemnification coverages(b)	3		4
JDA revenue(c)	54		31
JDA expense(c)	34		16
Intercompany natural gas purchases(d)	19		19
Duke Energy Florida
Corporate governance and shared service expenses(a)	$	73	$	70
Indemnification coverages(b)	5		6
Duke Energy Ohio
Corporate governance and shared service expenses(a)	$	89	$	92
Indemnification coverages(b)	1		1
Duke Energy Indiana
Corporate governance and shared service expenses(a)	$	101	$	95
Indemnification coverages(b)	2		2
Piedmont
Corporate governance and shared service expenses(a)	$	36	$	5
Indemnification coverages(b)	1		1
Intercompany natural gas sales(d)	23		20

(a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are primarily recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(c) Duke Energy Carolinas and Duke Energy Progress participate in a Joint Dispatch Agreement (JDA), which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power and expenses from the purchase of power pursuant to the JDA are recorded in Operating Revenues and Fuel used in electric generation and purchased power, respectively, on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(d) Piedmont provides long-term natural gas delivery service to certain Duke Energy Carolinas and Duke Energy Progress natural gas-fired generation facilities. Piedmont records the sales in Regulated natural gas revenues, and Duke Energy Carolinas and Duke Energy Progress record the related purchases in Fuel used in electric generation and purchased power on their respective Condensed Consolidated Statements of Operations and Comprehensive Income. The amounts are not eliminated in accordance with rate-based accounting regulations.

In addition to the amounts presented above, the Subsidiary Registrants have other affiliate transactions, including rental of office space, participation in a money pool arrangement, other operational transactions and their proportionate share of certain charged expenses. See Note 6 to the Consolidated Financial Statements in the Annual Report on Form 10-K/A for the year ended December 31, 2017, for more information regarding the money pool. These transactions of the Subsidiary Registrants were not material for the three months ended March 31, 2018, and 2017.

As discussed in Note 11, certain trade receivables have been sold by Duke Energy Ohio and Duke Energy Indiana to Cinergy Receivables Company LLC (CRC), an affiliate formed by a subsidiary of Duke Energy. The proceeds obtained from the sales of receivables are largely cash but also include a subordinated note from the affiliate for a portion of the purchase price.

Equity Method Investments

Piedmont has related party transactions as a customer of its equity method investments in natural gas storage and transportation facilities. The following table presents expenses for the three months ended March 31, 2018, and 2017, which are included in Cost of natural gas on Piedmont's Condensed Consolidated Statements of Operations and Comprehensive Income.

		Three Months Ended March 31,
(in millions)	Type of expense	2018		2017
Cardinal	Transportation Costs	$	2	$	2
Pine Needle	Natural Gas Storage Costs	2		2
Hardy Storage	Natural Gas Storage Costs	2		2
Total		$	6	$	6

Piedmont had accounts payable to its equity method investments of $2 million at March 31, 2018, and December 31, 2017, related to these transactions. These amounts are included in Accounts payable on the Condensed Consolidated Balance Sheets.

Intercompany Income Taxes

Duke Energy and the Subsidiary Registrants file a consolidated federal income tax return and other state and jurisdictional returns. The Subsidiary Registrants have a tax sharing agreement with Duke Energy for the allocation of consolidated tax liabilities and benefits. Income taxes recorded represent amounts the Subsidiary Registrants would incur as separate C-Corporations. The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants.

	Duke				Duke		Duke		Duke		Duke
	Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
March 31, 2018
Intercompany income tax receivable	$	—	$	183	$	13	$	9	$	—	$	—	$	—
Intercompany income tax payable	9		—		—		—		3		18		43
December 31, 2017
Intercompany income tax receivable	$	—	$	168	$	—	$	44	$	22	$	—	$	7
Intercompany income tax payable	44		—		21		—		—		35		—

XML

Derivatives and Hedging

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivatives and Hedging

DERIVATIVES AND HEDGING

The Duke Energy Registrants use commodity and interest rate contracts to manage commodity price risk and interest rate risk. The primary use of commodity derivatives is to hedge the generation portfolio against changes in the prices of electricity and natural gas. Piedmont enters into natural gas supply contracts to provide diversification, reliability and natural gas cost benefits to its customers. Interest rate swaps are used to manage interest rate risk associated with borrowings.

All derivative instruments not identified as NPNS are recorded at fair value as assets or liabilities on the Condensed Consolidated Balance Sheets. Cash collateral related to derivative instruments executed under master netting arrangements is offset against the collateralized derivatives on the Condensed Consolidated Balance Sheets. The cash impacts of settled derivatives are recorded as operating activities on the Condensed Consolidated Statements of Cash Flows.

INTEREST RATE RISK

The Duke Energy Registrants are exposed to changes in interest rates as a result of their issuance or anticipated issuance of variable-rate and fixed-rate debt and commercial paper. Interest rate risk is managed by limiting variable-rate exposures to a percentage of total debt and by monitoring changes in interest rates. To manage risk associated with changes in interest rates, the Duke Energy Registrants may enter into interest rate swaps, U.S. Treasury lock agreements and other financial contracts. In anticipation of certain fixed-rate debt issuances, a series of forward-starting interest rate swaps or Treasury locks may be executed to lock in components of current market interest rates. These instruments are later terminated prior to or upon the issuance of the corresponding debt.

Cash Flow Hedges

For a derivative designated as hedging the exposure to variable cash flows of a future transaction, referred to as a cash flow hedge, the effective portion of the derivative's gain or loss is initially reported as a component of other comprehensive income and subsequently reclassified into earnings once the future transaction impacts earnings. Amounts for interest rate contracts are reclassified to earnings as interest expense over the term of the related debt. Gains and losses reclassified out of AOCI for the three months ended March 31, 2018 and 2017 were not material. Duke Energy's interest rate derivatives designated as hedges include interest rate swaps used to hedge existing debt within the Commercial Renewables business.

Undesignated Contracts

Undesignated contracts include contracts not designated as a hedge because they are accounted for under regulatory accounting and contracts that do not qualify for hedge accounting.

Duke Energy’s interest rate swaps for its regulated operations employ regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the swaps are deferred as regulatory liabilities or regulatory assets, respectively. Regulatory assets and liabilities are amortized consistent with the treatment of the related costs in the ratemaking process. The accrual of interest on the swaps is recorded as Interest Expense.

The following table shows notional amounts of outstanding derivatives related to interest rate risk.

	March 31, 2018
			Duke				Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio
Cash flow hedges(a)	$	660	$	—	$	—	$	—	$	—	$	—
Undesignated contracts	527		—		500		250		250		27
Total notional amount	$	1,187	$	—	$	500	$	250	$	250	$	27

	December 31, 2017
			Duke				Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio
Cash flow hedges(a)	$	660	$	—	$	—	$	—	$	—	$	—
Undesignated contracts	927		400		500		250		250		27
Total notional amount	$	1,587	$	400	$	500	$	250	$	250	$	27

(a) Duke Energy includes amounts related to consolidated VIEs of $660 million as of March 31, 2018, and December 31, 2017.

COMMODITY PRICE RISK

The Duke Energy Registrants are exposed to the impact of changes in the prices of electricity purchased and sold in bulk power markets and coal and natural gas purchases, including Piedmont's natural gas supply contracts. Exposure to commodity price risk is influenced by a number of factors including the term of contracts, the liquidity of markets and delivery locations. For the Subsidiary Registrants, bulk power electricity and coal and natural gas purchases flow through fuel adjustment clauses, formula-based contracts or other cost-sharing mechanisms. Differences between the costs included in rates and the incurred costs, including undesignated derivative contracts, are largely deferred as regulatory assets or regulatory liabilities. Piedmont policies allow for the use of financial instruments to hedge commodity price risks. The strategy and objective of these hedging programs are to use the financial instruments to reduce natural gas costs volatility for customers.

Volumes

The tables below include volumes of outstanding commodity derivatives. Amounts disclosed represent the absolute value of notional volumes of commodity contracts excluding NPNS. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown.

	March 31, 2018
		Duke		Duke	Duke	Duke
	Duke	Energy	Progress	Energy	Energy	Energy
	Energy	Carolinas	Energy	Progress	Florida	Indiana	Piedmont
Electricity (gigawatt-hours)	16	—	—	—	—	16	—
Natural gas (millions of dekatherms)	765	110	179	149	30	2	474

	December 31, 2017
		Duke		Duke	Duke	Duke
	Duke	Energy	Progress	Energy	Energy	Energy
	Energy	Carolinas	Energy	Progress	Florida	Indiana	Piedmont
Electricity (gigawatt-hours)	34	—	—	—	—	34	—
Natural gas (millions of dekatherms)	770	105	183	133	50	2	480

LOCATION AND FAIR VALUE OF DERIVATIVE ASSETS AND LIABILITIES RECOGNIZED ON THE CONDENSED CONSOLIDATED BALANCE SHEETS

The following tables show the fair value and balance sheet location of derivative instruments. Although derivatives subject to master netting arrangements are netted on the Condensed Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.

Derivative Assets	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	14	$	2	$	3	$	2	$	1	$	1	$	7	$	1
Noncurrent	1		—		—		—		—		—		—		—
Total Derivative Assets – Commodity Contracts	$	15	$	2	$	3	$	2	$	1	$	1	$	7	$	1
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	1	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	21		—		—		—		—		—		—		—
Total Derivative Assets – Interest Rate Contracts	$	22	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Total Derivative Assets	$	37	$	2	$	3	$	2	$	1	$	1	$	7	$	1

Derivative Liabilities	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	26	$	5	$	8	$	6	$	3	$	—	$	—	$	13
Noncurrent	140		6		15		6		—		—		—		119
Total Derivative Liabilities – Commodity Contracts	$	166	$	11	$	23	$	12	$	3	$	—	$	—	$	132
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	4	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	3		—		—		—		—		—		—		—
Not Designated as Hedging Instruments
Current	3		—		3		2		1		—		—		—
Noncurrent	14		—		11		7		3		4		—		—
Total Derivative Liabilities – Interest Rate Contracts	$	24	$	—	$	14	$	9	$	4	$	4	$	—	$	—
Total Derivative Liabilities	$	190	$	11	$	37	$	21	$	7	$	4	$	—	$	132

Derivative Assets	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	34	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Noncurrent	1		—		1		1		—		—		—		—
Total Derivative Assets – Commodity Contracts	$	35	$	2	$	3	$	2	$	1	$	1	$	27	$	2
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	1	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	15		—		—		—		—		—		—		—
Total Derivative Assets – Interest Rate Contracts	$	16	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Total Derivative Assets	$	51	$	2	$	3	$	2	$	1	$	1	$	27	$	2

Derivative Liabilities	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	36	$	6	$	18	$	8	$	10	$	—	$	—	$	11
Noncurrent	146		4		10		4		—		—		—		131
Total Derivative Liabilities – Commodity Contracts	$	182	$	10	$	28	$	12	$	10	$	—	$	—	$	142
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	29	$	25	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	6		—		—		—		—		—		—		—
Not Designated as Hedging Instruments
Current	1		—		1		—		—		1		—		—
Noncurrent	12		—		7		6		2		4		—		—
Total Derivative Liabilities – Interest Rate Contracts	$	48	$	25	$	8	$	6	$	2	$	5	$	—	$	—
Total Derivative Liabilities	$	230	$	35	$	36	$	18	$	12	$	5	$	—	$	142

OFFSETTING ASSETS AND LIABILITIES

The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.

Derivative Assets	March 31, 2018
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	15		$	2		$	3		$	2		$	1	$	1	$	7	$	1
Gross amounts offset	(2		)	(1		)	(1		)	(1		)	—		—		—		—
Net amounts presented in Current Assets: Other	$	13		$	1		$	2		$	1		$	1	$	1	$	7	$	1
Noncurrent
Gross amounts recognized	$	22		$	—		$	—		$	—		$	—	$	—	$	—	$	—
Gross amounts offset	—			—			—			—			—		—		—		—
Net amounts presented in Other Noncurrent Assets: Other	$	22		$	—		$	—		$	—		$	—	$	—	$	—	$	—

Derivative Liabilities	March 31, 2018
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	33		$	5		$	11		$	8		$	4	$	—	$	—	$	13
Gross amounts offset	(4		)	(2		)	(2		)	(2		)	—		—		—		—
Net amounts presented in Current Liabilities: Other	$	29		$	3		$	9		$	6		$	4	$	—	$	—	$	13
Noncurrent
Gross amounts recognized	$	157		$	6		$	26		$	13		$	3	$	4	$	—	$	119
Gross amounts offset	(1		)	—			(1		)	(1		)	—		—		—		—
Net amounts presented in Other Noncurrent Liabilities: Other	$	156		$	6		$	25		$	12		$	3	$	4	$	—	$	119

Derivative Assets	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	35	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Gross amounts offset	—		—		—		—		—		—		—		—
Net amounts presented in Current Assets: Other	$	35	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Noncurrent
Gross amounts recognized	$	16	$	—	$	1	$	1	$	—	$	—	$	—	$	—
Gross amounts offset	—		—		—		—		—		—		—		—
Net amounts presented in Other Noncurrent Assets: Other	$	16	$	—	$	1	$	1	$	—	$	—	$	—	$	—

Derivative Liabilities	December 31, 2017
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	66		$	31		$	19		$	8		$	10	$	1	$	—	$	11
Gross amounts offset	(3		)	(2		)	(2		)	(2		)	—		—		—		—
Net amounts presented in Current Liabilities: Other	$	63		$	29		$	17		$	6		$	10	$	1	$	—	$	11
Noncurrent
Gross amounts recognized	$	164		$	4		$	17		$	10		$	2	$	4	$	—	$	131
Gross amounts offset	(1		)	—			(1		)	(1		)	—		—		—		—
Net amounts presented in Other Noncurrent Liabilities: Other	$	163		$	4		$	16		$	9		$	2	$	4	$	—	$	131

OBJECTIVE CREDIT CONTINGENT FEATURES

Certain derivative contracts contain objective credit contingent features. These features include the requirement to post cash collateral or letters of credit if specific events occur, such as a credit rating downgrade below investment grade. The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk-related payment provisions.

	March 31, 2018
			Duke				Duke		Duke
	Duke		Energy		Progress		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida
Aggregate fair value of derivatives in a net liability position	$	30	$	10	$	20	$	18	$	2
Fair value of collateral already posted	—		—		—		—		—
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	30		10		20		18		2

	December 31, 2017
			Duke				Duke		Duke
	Duke		Energy		Progress		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida
Aggregate fair value of derivatives in a net liability position	$	59	$	35	$	25	$	15	$	10
Fair value of collateral already posted	—		—		—		—		—
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	59		35		25		15		10

The Duke Energy Registrants have elected to offset cash collateral and fair values of derivatives. For amounts to be netted, the derivative and cash collateral must be executed with the same counterparty under the same master netting arrangement.

XML

Investments in Debt and Equity Securities

3 Months Ended

Mar. 31, 2018

Investments, Debt and Equity Securities [Abstract]

Investments In Debt And Equity Securities

INVESTMENTS IN DEBT AND EQUITY SECURITIES

Duke Energy’s investments in debt and equity securities are primarily comprised of investments held in (i) the nuclear decommissioning trust fund (NDTF) at Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, (ii) grantor trusts at Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana related to Other Post-Retirement Benefit Obligations (OPEB) plans and (iii) Bison. The Duke Energy Registrants classify investments in debt securities as available-for-sale (AFS) and investments in equity securities as fair value through net income (FV-NI). 

For investments in debt securities classified as AFS, the unrealized gains and losses are included in other comprehensive income until realized, at which time, they are reported through net income. For investments in equity securities classified as FV-NI, both realized and unrealized gains and losses are reported through net income. Substantially all of Duke Energy’s investments in debt and equity securities qualify for regulatory accounting, and accordingly, all associated realized and unrealized gains and losses on these investments are deferred as a regulatory asset or liability.

Duke Energy classifies the majority of investments in debt and equity securities as long term, unless otherwise noted.

Investment Trusts

The investments within the NDTF investments and the Duke Energy Progress, Duke Energy Florida and Duke Energy Indiana grantor trusts (Investment Trusts) are managed by independent investment managers with discretion to buy, sell and invest pursuant to the objectives set forth by the trust agreements. The Duke Energy Registrants have limited oversight of the day-to-day management of these investments. As a result, the ability to hold investments in unrealized loss positions is outside the control of the Duke Energy Registrants. Accordingly, all unrealized losses associated with debt securities within the Investment Trusts are considered OTTIs and are recognized immediately and deferred to regulatory accounts where appropriate.

Other AFS Securities

Unrealized gains and losses on all other AFS securities are included in other comprehensive income until realized, unless it is determined the carrying value of an investment is other-than-temporarily impaired. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value should be considered other-than-temporary. If an OTTI exists, the unrealized credit loss is included in earnings. There were no material credit losses as of March 31, 2018, and December 31, 2017.

Other Investments amounts are recorded in Other within Other Noncurrent Assets on the Condensed Consolidated Balance Sheets.

DUKE ENERGY

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	143	$	—	$	—	$	115
Equity securities	2,751		38		4,857		2,805		27		4,914
Corporate debt securities	7		8		549		17		2		570
Municipal bonds	1		5		333		4		3		344
U.S. government bonds	6		18		1,014		11		7		1,027
Other debt securities	—		2		130		—		1		118
Total NDTF Investments	$	2,765	$	71	$	7,026	$	2,837	$	40	$	7,088
Other Investments
Cash and cash equivalents	$	—	$	—	$	15	$	—	$	—	$	15
Equity securities	57		—		130		59		—		123
Corporate debt securities	—		1		64		1		—		57
Municipal bonds	1		1		80		2		1		83
U.S. government bonds	—		1		51		—		—		41
Other debt securities	—		—		48		—		1		44
Total Other Investments	$	58	$	3	$	388	$	62	$	2	$	363
Total Investments	$	2,823	$	74	$	7,414	$	2,899	$	42	$	7,451

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	100
Due after one through five years	535
Due after five through 10 years	530
Due after 10 years	1,104
Total	$	2,269

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	19
Realized losses	13
AFS:
Realized gains	5
Realized losses	13

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	93
Realized losses	62

DUKE ENERGY CAROLINAS

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	32
Equity securities	1,502		20		2,669		1,531		12		2,692
Corporate debt securities	3		5		333		9		2		359
Municipal bonds	—		1		69		—		1		60
U.S. government bonds	2		11		494		3		4		503
Other debt securities	—		2		122		—		1		112
Total NDTF Investments	$	1,507	$	39	$	3,737	$	1,543	$	20	$	3,758

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	11
Due after one through five years	178
Due after five through 10 years	285
Due after 10 years	544
Total	$	1,018

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	10
Realized losses	5
AFS:
Realized gains	5
Realized losses	10

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	66
Realized losses	40

PROGRESS ENERGY

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	93	$	—	$	—	$	83
Equity securities	1,249		18		2,188		1,274		15		2,222
Corporate debt securities	4		3		216		8		—		211
Municipal bonds	1		4		264		4		2		284
U.S. government bonds	4		7		520		8		3		524
Other debt securities	—		—		8		—		—		6
Total NDTF Investments	$	1,258	$	32	$	3,289	$	1,294	$	20	$	3,330
Other Investments
Cash and cash equivalents	$	—	$	—	$	10	$	—	$	—	$	12
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	57	$	2	$	—	$	59
Total Investments	$	1,259	$	32	$	3,346	$	1,296	$	20	$	3,389

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	75
Due after one through five years	300
Due after five through 10 years	198
Due after 10 years	482
Total	$	1,055

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	9
Realized losses	8
AFS:
Realized losses	3

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	27
Realized losses	21

DUKE ENERGY PROGRESS

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	59	$	—	$	—	$	50
Equity securities	959		14		1,765		980		12		1,795
Corporate debt securities	3		2		153		6		—		149
Municipal bonds	1		4		263		4		2		283
U.S. government bonds	3		5		326		5		2		310
Other debt securities	—		—		5		—		—		4
Total NDTF Investments	$	966	$	25	$	2,571	$	995	$	16	$	2,591
Other Investments
Cash and cash equivalents	$	—	$	—	$	1	$	—	$	—	$	1
Total Other Investments	$	—	$	—	$	1	$	—	$	—	$	1
Total Investments	$	966	$	25	$	2,572	$	995	$	16	$	2,592

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	19
Due after one through five years	216
Due after five through 10 years	144
Due after 10 years	368
Total	$	747

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	8
Realized losses	8
AFS:
Realized losses	2

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	24
Realized losses	19

DUKE ENERGY FLORIDA

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	34	$	—	$	—	$	33
Equity securities	290		4		423		294		3		427
Corporate debt securities	1		1		63		2		—		62
Municipal bonds	—		—		1		—		—		1
U.S. government bonds	1		2		194		3		1		214
Other debt securities	—		—		3		—		—		2
Total NDTF Investments(b)	$	292	$	7	$	718	$	299	$	4	$	739
Other Investments
Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	47	$	2	$	—	$	48
Total Investments	$	293	$	7	$	765	$	301	$	4	$	787

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

(b) During the three months endedMarch 31, 2018, Duke Energy Florida continued to receive reimbursements from the NDTF for costs related to ongoing decommissioning activity of the Crystal River Unit 3 nuclear plant.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	56
Due after one through five years	84
Due after five through 10 years	54
Due after 10 years	114
Total	$	308

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	1
AFS:
Realized losses	1

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	3
Realized losses	2

DUKE ENERGY INDIANA

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
Investments
Equity securities	$	48	$	—	$	96	$	49	$	—	$	97
Corporate debt securities	—		—		5		—		—		3
Municipal bonds	—		1		26		—		1		28
Total Investments	$	48	$	1	$	127	$	49	$	1	$	128

(a) Realized and unrealized gains and losses where regulatory accounting is applied are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	3
Due after one through five years	15
Due after five through 10 years	6
Due after 10 years	7
Total	$	31

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018, and from sales of AFS securities for the three months ended March 31, 2017, were insignificant.

XML

Fair Value Measurements

3 Months Ended

Mar. 31, 2018

Fair Value Disclosures [Abstract]

Fair Value Measurements

FAIR VALUE MEASUREMENTS

Fair value is the exchange price to sell an asset or transfer a liability in an orderly transaction between market participants at the measurement date. The fair value definition focuses on an exit price versus the acquisition cost. Fair value measurements use market data or assumptions market participants would use in pricing the asset or liability, including assumptions about risk and the risks inherent in the inputs to the valuation technique. These inputs may be readily observable, corroborated by market data or generally unobservable. Valuation techniques maximize the use of observable inputs and minimize use of unobservable inputs. A midmarket pricing convention (the midpoint price between bid and ask prices) is permitted for use as a practical expedient.

Fair value measurements are classified in three levels based on the fair value hierarchy:

Level 1 – Unadjusted quoted prices in active markets for identical assets or liabilities that the reporting entity can access at the measurement date. An active market is one in which transactions for an asset or liability occur with sufficient frequency and volume to provide ongoing pricing information.

Level 2 – A fair value measurement utilizing inputs other than quoted prices included in Level 1 that are observable, either directly or indirectly, for an asset or liability. Inputs include (i) quoted prices for similar assets or liabilities in active markets, (ii) quoted prices for identical or similar assets or liabilities in markets that are not active and (iii) inputs other than quoted market prices that are observable for the asset or liability, such as interest rate curves and yield curves observable at commonly quoted intervals, volatilities and credit spreads. A Level 2 measurement cannot have more than an insignificant portion of its valuation based on unobservable inputs. Instruments in this category include non-exchange-traded derivatives, such as over-the-counter forwards, swaps and options; certain marketable debt securities; and financial instruments traded in less-than-active markets.

Level 3 – Any fair value measurement that includes unobservable inputs for more than an insignificant portion of the valuation. These inputs may be used with internally developed methodologies that result in management’s best estimate of fair value. Level 3 measurements may include longer-term instruments that extend into periods in which observable inputs are not available.

Not Categorized – Certain investments are not categorized within the Fair Value hierarchy. These investments are measured at fair value using the net asset value (NAV) per share practical expedient. The NAV is derived based on the investment cost, less any impairment, plus or minus changes resulting from observable price changes for an identical or similar investment of the same issuer.

Fair value accounting guidance permits entities to elect to measure certain financial instruments that are not required to be accounted for at fair value, such as equity method investments or the company’s own debt, at fair value. The Duke Energy Registrants have not elected to record any of these items at fair value.

Transfers between levels represent assets or liabilities that were previously (i) categorized at a higher level for which the inputs to the estimate became less observable or (ii) classified at a lower level for which the inputs became more observable during the period. The Duke Energy Registrant’s policy is to recognize transfers between levels of the fair value hierarchy at the end of the period. There were no transfers between levels during the three months endedMarch 31, 2018, and 2017.

Valuation methods of the primary fair value measurements disclosed below are as follows.

Investments in equity securities

The majority of investments in equity securities are valued using Level 1 measurements. Investments in equity securities are typically valued at the closing price in the principal active market as of the last business day of the quarter. Principal active markets for equity prices include published exchanges such as New York Stock Exchange and Nasdaq Stock Market. Foreign equity prices are translated from their trading currency using the currency exchange rate in effect at the close of the principal active market. There was no after-hours market activity that was required to be reflected in the reported fair value measurements.

Investments in debt securities

Most investments in debt securities are valued using Level 2 measurements because the valuations use interest rate curves and credit spreads applied to the terms of the debt instrument (maturity and coupon interest rate) and consider the counterparty credit rating. If the market for a particular fixed-income security is relatively inactive or illiquid, the measurement is Level 3.

Commodity derivatives

Commodity derivatives with clearinghouses are classified as Level 1. Other commodity derivatives, including Piedmont's natural gas supply contracts, are primarily valued using internally developed discounted cash flow models that incorporate forward price, adjustments for liquidity (bid-ask spread) and credit or non-performance risk (after reflecting credit enhancements such as collateral), and are discounted to present value. Pricing inputs are derived from published exchange transaction prices and other observable data sources. In the absence of an active market, the last available price may be used. If forward price curves are not observable for the full term of the contract and the unobservable period had more than an insignificant impact on the valuation, the commodity derivative is classified as Level 3. In isolation, increases (decreases) in natural gas forward prices result in favorable (unfavorable) fair value adjustments for natural gas purchase contracts; and increases (decreases) in electricity forward prices result in unfavorable (favorable) fair value adjustments for electricity sales contracts. Duke Energy regularly evaluates and validates pricing inputs used to estimate the fair value of natural gas commodity contracts by a market participant price verification procedure. This procedure provides a comparison of internal forward commodity curves to market participant generated curves.

Interest rate derivatives

Most over-the-counter interest rate contract derivatives are valued using financial models that utilize observable inputs for similar instruments and are classified as Level 2. Inputs include forward interest rate curves, notional amounts, interest rates and credit quality of the counterparties.

Other fair value considerations

See Note 11 in Duke Energy's Annual Report on Form 10-K/A for the year ended December 31, 2017, for a discussion of the valuation of goodwill and intangible assets.

DUKE ENERGY

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the tables below for all Duke Energy Registrants exclude cash collateral, which is disclosed in Note 8. See Note 9 for additional information related to investments by major security type for the Duke Energy Registrants.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2			Level 3			Not Categorized
NDTF equity securities	$	4,857		$	4,785		$	—		$	—		$	72
NDTF debt securities	2,169			633			1,536			—			—
Other equity securities	130			130			—			—			—
Other debt securities	258			66			192			—			—
Derivative assets	37			2			27			8			—
Total assets	7,451			5,616			1,755			8			72
Derivative liabilities	(190		)	(1		)	(57		)	(132		)	—
Net assets (liabilities)	$	7,261		$	5,615		$	1,698		$	(124	)	$	72

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2			Level 3			Not Categorized
NDTF equity securities	$	4,914		$	4,840		$	—		$	—		$	74
NDTF debt securities	2,174			635			1,539			—			—
Other equity securities	123			123			—			—			—
Other debt securities	241			57			184			—			—
Derivative assets	51			3			20			28			—
Total assets	7,503			5,658			1,743			28			74
Derivative liabilities	(230		)	(2		)	(86		)	(142		)	—
Net assets (liabilities)	$	7,273		$	5,656		$	1,657		$	(114	)	$	74

The following table provides reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Amounts included in earnings for derivatives are primarily included in Cost of natural gas on the Duke Energy Registrants' Condensed Consolidated Statements of Operations and Comprehensive Income. Amounts included in changes of net assets on the Duke Energy Registrants' Condensed Consolidated Balance Sheets are included in regulatory assets or liabilities. All derivative assets and liabilities are presented on a net basis.

	Three Months Ended March 31, 2018								Three Months Ended March 31, 2017
(in millions)	Investments		Derivatives (net)			Total			Investments		Derivatives (net)			Total
Balance at beginning of period	$	—	$	(114	)	$	(114	)	$	5	$	(166	)	$	(161	)
Purchases, sales, issuances and settlements:
Settlements	—		(14		)	(14		)	—		(9		)	(9		)
Total gains included on the Condensed Consolidated Balance Sheet	—		4			4			—		40			40
Balance at end of period	$	—	$	(124	)	$	(124	)	$	5	$	(135	)	$	(130	)

DUKE ENERGY CAROLINAS

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2			Not Categorized
NDTF equity securities	$	2,669		$	2,597		$	—		$	72
NDTF debt securities	1,068			209			859			—
Derivative assets	2			—			2			—
Total assets	3,739			2,806			861			72
Derivative liabilities	(11		)	(1		)	(10		)	—
Net assets	$	3,728		$	2,805		$	851		$	72

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2			Not Categorized
NDTF equity securities	$	2,692		$	2,618		$	—		$	74
NDTF debt securities	1,066			204			862			—
Derivative assets	2			—			2			—
Total assets	3,760			2,822			864			74
Derivative liabilities	(35		)	(1		)	(34		)	—
Net assets	$	3,725		$	2,821		$	830		$	74

PROGRESS ENERGY

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	2,188		$	2,188		$	—
NDTF debt securities	1,101			424			677
Other debt securities	57			10			47
Derivative assets	3			—			3
Total assets	3,349			2,622			727
Derivative liabilities	(37		)	(1		)	(36		)
Net assets	$	3,312		$	2,621		$	691

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	2,222		$	2,222		$	—
NDTF debt securities	1,108			431			677
Other debt securities	59			12			47
Derivative assets	3			1			2
Total assets	3,392			2,666			726
Derivative liabilities	(36		)	(1		)	(35		)
Net assets	$	3,356		$	2,665		$	691

DUKE ENERGY PROGRESS

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	1,765		$	1,765		$	—
NDTF debt securities	806			254			552
Other debt securities	1			1			—
Derivative assets	2			—			2
Total assets	2,574			2,020			554
Derivative liabilities	(21		)	(1		)	(20		)
Net assets	$	2,553		$	2,019		$	534

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	1,795		$	1,795		$	—
NDTF debt securities	796			243			553
Other debt securities	1			1			—
Derivative assets	2			1			1
Total assets	2,594			2,040			554
Derivative liabilities	(18		)	(1		)	(17		)
Net assets	$	2,576		$	2,039		$	537

DUKE ENERGY FLORIDA

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1		Level 2
NDTF equity securities	$	423		$	423	$	—
NDTF debt securities	295			170		125
Other debt securities	47			—		47
Derivative assets	1			—		1
Total assets	766			593		173
Derivative liabilities	(7		)	—		(7		)
Net assets	$	759		$	593	$	166

	December 31, 2017
(in millions)	Total Fair Value			Level 1		Level 2
NDTF equity securities	$	427		$	427	$	—
NDTF debt securities	312			188		124
Other debt securities	48			1		47
Derivative assets	1			—		1
Total assets	788			616		172
Derivative liabilities	(12		)	—		(12		)
Net assets	$	776		$	616	$	160

DUKE ENERGY OHIO

The following table provides recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018								December 31, 2017
(in millions)	Total Fair Value			Level 2			Level 3		Total Fair Value			Level 2			Level 3
Derivative assets	$	1		$	—		$	1	$	1		$	—		$	1
Derivative liabilities	(4		)	(4		)	—		(5		)	(5		)	—
Net (liabilities) assets	$	(3	)	$	(4	)	$	1	$	(4	)	$	(5	)	$	1

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018		2017
Balance at beginning of period	$	1	$	5
Purchases, sales, issuances and settlements:
Settlements	—		(1		)
Total losses included on the Condensed Consolidated Balance Sheet	—		(3		)
Balance at end of period	$	1	$	1

DUKE ENERGY INDIANA

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value		Level 1		Level 2		Level 3
Other equity securities	$	96	$	96	$	—	$	—
Other debt securities	31		—		31		—
Derivative assets	7		—		—		7
Total assets	134		96		31		7
Derivative liabilities	—		—		—		—
Net assets	$	134	$	96	$	31	$	7

	December 31, 2017
(in millions)	Total Fair Value		Level 1		Level 2		Level 3
Other equity securities	$	97	$	97	$	—	$	—
Other debt securities	31		—		31		—
Derivative assets	27		—		—		27
Total assets	155		97		31		27
Derivative liabilities	—		—		—		—
Net assets	$	155	$	97	$	31	$	27

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018			2017
Balance at beginning of period	$	27		$	16
Purchases, sales, issuances and settlements:
Settlements	(14		)	(7		)
Total (losses) gains included on the Condensed Consolidated Balance Sheet	(6		)	—
Balance at end of period	$	7		$	9

PIEDMONT

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1		Level 3
Derivative assets	$	1		$	1	$	—
Derivative liabilities	(132		)	—		(132		)
Net (liabilities) assets	$	(131	)	$	1	$	(132	)

	December 31, 2017
(in millions)	Total Fair Value			Level 1		Level 3
Other debt securities	$	1		$	1	$	—
Derivative assets	2			2		—
Total assets	3			3		—
Derivative liabilities	(142		)	—		(142		)
Net (liabilities) assets	$	(139	)	$	3	$	(142	)

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018			2017
Balance at beginning of period	$	(142	)	$	(187	)
Total gains and settlements	10			42
Balance at end of period	$	(132	)	$	(145	)

QUANTITATIVE INFORMATION ABOUT UNOBSERVABLE INPUTS

The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3.

	March 31, 2018
	Fair Value
Investment Type	(in millions)			Valuation Technique	Unobservable Input	Range
Duke Energy Ohio
Financial Transmission Rights (FTRs)	$	1		RTO auction pricing	FTR price – per megawatt-hour (MWh)	$	—		-	$	2.88
Duke Energy Indiana
FTRs	7			RTO auction pricing	FTR price – per MWh	(5.09		)	-	7.58
Piedmont
Natural gas contracts	(132		)	Discounted cash flow	Forward natural gas curves – price per million British thermal unit (MMBtu)	2.15			-	3.65
Duke Energy
Total Level 3 derivatives	$	(124	)

	December 31, 2017
	Fair Value
Investment Type	(in millions)			Valuation Technique	Unobservable Input	Range
Duke Energy Ohio
FTRs	$	1		RTO auction pricing	FTR price – per MWh	$	0.07		-	$	1.41
Duke Energy Indiana
FTRs	27			RTO auction pricing	FTR price – per MWh	(0.77		)	-	7.44
Piedmont
Natural gas contracts	(142		)	Discounted cash flow	Forward natural gas curves – price per MMBtu	2.10			-	2.88
Duke Energy
Total Level 3 derivatives	$	(114	)

OTHER FAIR VALUE DISCLOSURES

The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements.

	March 31, 2018				December 31, 2017
(in millions)	Book Value		Fair Value		Book Value		Fair Value
Duke Energy	$	52,981	$	54,383	$	52,279	$	55,331
Duke Energy Carolinas	10,694		11,556		10,103		11,372
Progress Energy	17,757		19,270		17,837		20,000
Duke Energy Progress	7,357		7,687		7,357		7,992
Duke Energy Florida	7,015		7,632		7,095		7,953
Duke Energy Ohio	2,067		2,217		2,067		2,249
Duke Energy Indiana	3,782		4,322		3,783		4,464
Piedmont	2,037		2,209		2,037		2,209

At both March 31, 2018, and December 31, 2017, fair value of cash and cash equivalents, accounts and notes receivable, accounts payable, notes payable and commercial paper, and nonrecourse notes payable of VIEs are not materially different from their carrying amounts because of the short-term nature of these instruments and/or because the stated rates approximate market rates.

XML

Variable Interest Entities

3 Months Ended

Mar. 31, 2018

Variable Interest Entities [Abstract]

Variable Interest Entities

VARIABLE INTEREST ENTITIES

A VIE is an entity that is evaluated for consolidation using more than a simple analysis of voting control. The analysis to determine whether an entity is a VIE considers contracts with an entity, credit support for an entity, the adequacy of the equity investment of an entity and the relationship of voting power to the amount of equity invested in an entity. This analysis is performed either upon the creation of a legal entity or upon the occurrence of an event requiring re-evaluation, such as a significant change in an entity’s assets or activities. A qualitative analysis of control determines the party that consolidates a VIE. This assessment is based on (i) what party has the power to direct the activities of the VIE that most significantly impact its economic performance and (ii) what party has rights to receive benefits or is obligated to absorb losses that could potentially be significant to the VIE. The analysis of the party that consolidates a VIE is a continual reassessment.

CONSOLIDATED VIEs

The obligations of the consolidated VIEs discussed in the following paragraphs are nonrecourse to the Duke Energy registrants. The registrants have no requirement to provide liquidity to, purchase assets of or guarantee performance of these VIEs unless noted in the following paragraphs.

No financial support was provided to any of the consolidated VIEs during the three months ended March 31, 2018, and the year ended December 31, 2017, or is expected to be provided in the future, that was not previously contractually required.

Receivables Financing – DERF / DEPR / DEFR

Duke Energy Receivables Finance Company, LLC (DERF), Duke Energy Progress Receivables, LLC (DEPR) and Duke Energy Florida Receivables, LLC (DEFR) are bankruptcy remote, special purpose subsidiaries of Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida, respectively. DERF, DEPR and DEFR are wholly owned limited liability companies with separate legal existence from their parent companies, and their assets are not generally available to creditors of their parent companies. On a revolving basis, DERF, DEPR and DEFR buy certain accounts receivable arising from the sale of electricity and related services from their parent companies.

DERF, DEPR and DEFR borrow amounts under credit facilities to buy these receivables. Borrowing availability from the credit facilities is limited to the amount of qualified receivables purchased. The sole source of funds to satisfy the related debt obligations is cash collections from the receivables. Amounts borrowed under the credit facilities are reflected on the Condensed Consolidated Balance Sheets as Long-Term Debt.

The most significant activity that impacts the economic performance of DERF, DEPR and DEFR are the decisions made to manage delinquent receivables. Duke Energy Carolinas, Duke Energy Progress and Duke Energy Florida consolidate DERF, DEPR and DEFR, respectively, as they make those decisions.

Receivables Financing – CRC

CRC is a bankruptcy remote, special purpose entity indirectly owned by Duke Energy. On a revolving basis, CRC buys certain accounts receivable arising from the sale of electricity, natural gas and related services from Duke Energy Ohio and Duke Energy Indiana. CRC borrows amounts under a credit facility to buy the receivables from Duke Energy Ohio and Duke Energy Indiana. Borrowing availability from the credit facility is limited to the amount of qualified receivables sold to CRC. The sole source of funds to satisfy the related debt obligation is cash collections from the receivables. Amounts borrowed under the credit facility are reflected on Duke Energy's Condensed Consolidated Balance Sheets as Long-Term Debt.

The proceeds Duke Energy Ohio and Duke Energy Indiana receive from the sale of receivables to CRC are typically 75 percent cash and 25 percent in the form of a subordinated note from CRC. The subordinated note is a retained interest in the receivables sold. Depending on collection experience, additional equity infusions to CRC may be required by Duke Energy to maintain a minimum equity balance of $3 million.

CRC is considered a VIE because (i) equity capitalization is insufficient to support its operations, (ii) power to direct the activities that most significantly impact the economic performance of the entity are not performed by the equity holder and (iii) deficiencies in net worth of CRC are funded by Duke Energy. The most significant activities that impact the economic performance of CRC are decisions made to manage delinquent receivables. Duke Energy consolidates CRC as it makes these decisions. Neither Duke Energy Ohio nor Duke Energy Indiana consolidate CRC.

Receivables Financing – Credit Facilities

The following table summarizes the amounts and expiration dates of the credit facilities and associated restricted receivables described above.

	Duke Energy
			Duke Energy		Duke Energy		Duke Energy
			Carolinas		Progress		Florida
(in millions)	CRC		DERF		DEPR		DEFR
Expiration date	December 2020		December 2020		February 2021		April 2019		(a)
Credit facility amount	$	325	$	450	$	300	$	225
Amounts borrowed at March 31, 2018	325		450		300		225
Amounts borrowed at December 31, 2017	325		450		300		225
Restricted Receivables at March 31, 2018	504		634		497		313
Restricted Receivables at December 31, 2017	545		640		459		317

(a)    In April 2018, the credit facility was extended through April 2021.

Nuclear Asset-Recovery Bonds – DEFPF

Duke Energy Florida Project Finance, LLC (DEFPF) is a bankruptcy remote, wholly owned special purpose subsidiary of Duke Energy Florida. DEFPF was formed in 2016 for the sole purpose of issuing nuclear asset-recovery bonds to finance Duke Energy Florida's unrecovered regulatory asset related to Crystal River Unit 3.

In June 2016, DEFPF issued senior secured bonds and used the proceeds to acquire nuclear asset-recovery property from Duke Energy Florida. The nuclear asset-recovery property acquired includes the right to impose, bill, collect and adjust a non-bypassable nuclear asset-recovery charge from all Duke Energy Florida retail customers until the bonds are paid in full and all financing costs have been recovered. The nuclear asset-recovery bonds are secured by the nuclear asset-recovery property, and cash collections from the nuclear asset-recovery charges are the sole source of funds to satisfy the debt obligation. The bondholders have no recourse to Duke Energy Florida.

DEFPF is considered a VIE primarily because the equity capitalization is insufficient to support its operations. Duke Energy Florida has the power to direct the significant activities of the VIE as described above, and therefore Duke Energy Florida is considered the primary beneficiary and consolidates DEFPF.

The following table summarizes the impact of DEFPF on Duke Energy Florida's Condensed Consolidated Balance Sheets.

(in millions)	March 31, 2018		December 31, 2017
Receivables of VIEs	$	4	$	4
Regulatory Assets: Current	51		51
Current Assets: Other	13		40
Other Noncurrent Assets: Regulatory assets	1,082		1,091
Current Liabilities: Other	3		10
Current maturities of long-term debt	53		53
Long-Term Debt	1,136		1,164

Commercial Renewables

Certain of Duke Energy’s renewable energy facilities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. Assets are restricted and cannot be pledged as collateral or sold to third parties without prior approval of debt holders. The activities that most significantly impact the economic performance of these renewable energy facilities were decisions associated with siting, negotiating PPAs, engineering, procurement and construction and decisions associated with ongoing operations and maintenance-related activities. Duke Energy consolidates the entities as it is responsible for all of these decisions.

The table below presents material balances reported on Duke Energy's Condensed Consolidated Balance Sheets related to renewables VIEs.

(in millions)	March 31, 2018			December 31, 2017
Current Assets: Other	$	217		$	174
Property, plant and equipment, cost	4,017			3,923
Other Noncurrent Assets: Other	227			50
Accumulated depreciation and amortization	(626		)	(591		)
Current maturities of long-term debt	171			170
Long-Term Debt	1,700			1,700
Other Noncurrent Liabilities: Deferred income taxes	—			(148		)
Other Noncurrent Liabilities: Other	236			241

NON-CONSOLIDATED VIEs

The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets.

	March 31, 2018
	Duke Energy										Duke		Duke
	Pipeline			Commercial		Other					Energy		Energy
(in millions)	Investments			Renewables		VIEs		Total			Ohio		Indiana
Receivables from affiliated companies	$	—		$	—	$	—	$	—		$	65	$	86
Investments in equity method unconsolidated affiliates	723			183		45		951			—		—
Other noncurrent assets	17			—		—		17			—		—
Total assets	$	740		$	183	$	45	$	968		$	65	$	86
Taxes accrued	(29		)	—		—		(29		)	—		—
Other current liabilities	—			—		3		3			—		—
Deferred income taxes	32			—		—		32			—		—
Other noncurrent liabilities	8			—		12		20			—		—
Total liabilities	$	11		$	—	$	15	$	26		$	—	$	—
Net assets	$	729		$	183	$	30	$	942		$	65	$	86

	December 31, 2017
	Duke Energy										Duke		Duke
	Pipeline			Commercial		Other					Energy		Energy
(in millions)	Investments			Renewables		VIEs		Total			Ohio		Indiana
Receivables from affiliated companies	$	—		$	—	$	—	$	—		$	87	$	106
Investments in equity method unconsolidated affiliates	697			180		42		919			—		—
Other noncurrent assets	17			—		—		17			—		—
Total assets	$	714		$	180	$	42	$	936		$	87	$	106
Taxes accrued	(29		)	—		—		(29		)	—		—
Other current liabilities	—			—		4		4			—		—
Deferred income taxes	42			—		—		42			—		—
Other noncurrent liabilities	—			—		12		12			—		—
Total liabilities	$	13		$	—	$	16	$	29		$	—	$	—
Net assets	$	701		$	180	$	26	$	907		$	87	$	106

The Duke Energy Registrants are not aware of any situations where the maximum exposure to loss significantly exceeds the carrying values shown above except for the power purchase agreement with OVEC, which is discussed below, and various guarantees, some of which are reflected in the table above as Other noncurrent liabilities. For more information on various guarantees, refer to Note 4.

Pipeline Investments

Duke Energy has investments in various joint ventures with pipeline projects currently under construction. These entities are considered VIEs due to having insufficient equity to finance their own activities without subordinated financial support. Duke Energy does not have the power to direct the activities that most significantly impact the economic performance, the obligation to absorb losses or the right to receive benefits of these VIEs and therefore does not consolidate these entities.

The table below presents Duke Energy's ownership interest and investment balances in these joint ventures.

			VIE Investment Amount (in millions)
	Ownership		March 31,		December 31,
Entity Name	Interest		2018		2017
ACP	47	%	$	474	$	397
Sabal Trail	7.5	%	223		219
Constitution(a)	24	%	26		81
Total			$	723	$	697

(a) During the three months ended March 31, 2018, Duke Energy recorded an OTTI of $55 million related to Constitution within Equity in (losses) earnings of unconsolidated affiliates on Duke Energy's Condensed Consolidated Statements of Income. See Note 3 for additional information.

In 2017, ACP executed a $3.4 billion revolving credit facility with a stated maturity date of October 2021. Duke Energy entered into a guarantee agreement to support its share of the ACP revolving credit facility. Duke Energy's maximum exposure to loss under the terms of the guarantee is limited to 47 percent of the outstanding borrowings under the credit facility, which was $346 million as of March 31, 2018.

On April 30, 2018, Sabal Trail closed on a $1.5 billion offering of senior notes. The notes were issued in three tranches due in 2028, 2038 and 2048. Duke Energy received $112 million of net proceeds as a result of the offering. As a result of the financing, Sabal Trail has sufficient equity to finance its own activities without additional subordinated financial support from other parties and will no longer be considered a VIE.

Commercial Renewables

Duke Energy has investments in various renewable energy project entities. Some of these entities are VIEs due to Duke Energy issuing guarantees for debt service and operations and maintenance reserves in support of debt financings. Duke Energy does not consolidate these VIEs because power to direct and control key activities is shared jointly by Duke Energy and other owners.

Other VIEs

Duke Energy holds a 50 percent equity interest in Pioneer Transmission, LLC (Pioneer). Pioneer is considered a VIE due to having insufficient equity to finance its own activities without subordinated financial support. The activities that most significantly impact Pioneer's economic performance are decisions related to the development of new transmission facilities. The power to direct these activities is jointly and equally shared by Duke Energy and the other joint venture partner, American Electric Power; therefore, Duke Energy does not consolidate Pioneer.

OVEC

Duke Energy Ohio’s 9 percent ownership interest in OVEC is considered a non-consolidated VIE due to OVEC having insufficient equity to finance its activities without subordinated financial support. As a counterparty to an inter-company power agreement (ICPA), Duke Energy Ohio has a contractual arrangement to receive entitlements to capacity and energy from OVEC’s power plants through June 2040 commensurate with its power participation ratio, which is equivalent to Duke Energy Ohio's ownership interest. Costs, including fuel, operating expenses, fixed costs, debt amortization and interest expense, are allocated to counterparties to the ICPA based on their power participation ratio. The value of the ICPA is subject to variability due to fluctuation in power prices and changes in OVEC's cost of business. Deterioration in the credit quality or bankruptcy of one or more parties to the ICPA could increase the costs of OVEC. On March 31, 2018, FirstEnergy Solutions (FES), a subsidiary of FirstEnergy and counterparty to the ICPA, filed for Chapter 11 bankruptcy. FES has a power participation ratio of 4.85 percent. Duke Energy Ohio cannot predict the impact of the bankruptcy on its OVEC interests. In addition, certain proposed environmental rulemaking could result in future increased cost allocations.

CRC

See discussion under Consolidated VIEs for additional information related to CRC.

Amounts included in Receivables from affiliated companies in the above table for Duke Energy Ohio and Duke Energy Indiana reflect their retained interest in receivables sold to CRC. These subordinated notes held by Duke Energy Ohio and Duke Energy Indiana are stated at fair value. Carrying values of retained interests are determined by allocating carrying value of the receivables between assets sold and interests retained based on relative fair value. The allocated bases of the subordinated notes are not materially different than their face value because (i) the receivables generally turn over in less than two months, (ii) credit losses are reasonably predictable due to the broad customer base and lack of significant concentration and (iii) the equity in CRC is subordinate to all retained interests and thus would absorb losses first. The hypothetical effect on fair value of the retained interests assuming both a 10 percent and a 20 percent unfavorable variation in credit losses or discount rates is not material due to the short turnover of receivables and historically low credit loss history. Interest accrues to Duke Energy Ohio and Duke Energy Indiana on the retained interests using the acceptable yield method. This method generally approximates the stated rate on the notes since the allocated basis and the face value are nearly equivalent. An impairment charge is recorded against the carrying value of both retained interests and purchased beneficial interest whenever it is determined that an OTTI has occurred.

Key assumptions used in estimating fair value are detailed in the following table.

	Duke Energy Ohio				Duke Energy Indiana
	2018		2017		2018		2017
Anticipated credit loss ratio	0.5	%	0.5	%	0.3	%	0.3	%
Discount rate	2.6	%	2.1	%	2.6	%	2.1	%
Receivable turnover rate	13.6	%	13.5	%	10.8	%	10.7	%

The following table shows the gross and net receivables sold.

	Duke Energy Ohio				Duke Energy Indiana
(in millions)	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
Receivables sold	$	249	$	273	$	297	$	312
Less: Retained interests	65		87		86		106
Net receivables sold	$	184	$	186	$	211	$	206

The following table shows sales and cash flows related to receivables sold.

	Duke Energy Ohio				Duke Energy Indiana
	Three Months Ended				Three Months Ended
	March 31,				March 31,
(in millions)	2018		2017		2018		2017
Sales
Receivables sold	$	567	$	533	$	694	$	664
Loss recognized on sale	3		2		3		3
Cash flows
Cash proceeds from receivables sold	$	585	$	559	$	711	$	693
Return received on retained interests	2		1		2		2

Cash flows from sales of receivables are reflected within Operating Activities on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Cash Flows.

Collection fees received in connection with servicing transferred accounts receivable are included in Operation, maintenance and other on Duke Energy Ohio’s and Duke Energy Indiana’s Condensed Consolidated Statements of Operations and Comprehensive Income. The loss recognized on sales of receivables is calculated monthly by multiplying receivables sold during the month by the required discount. The required discount is derived monthly utilizing a three-year weighted average formula that considers charge-off history, late charge history and turnover history on the sold receivables, as well as a component for the time value of money. The discount rate, or component for the time value of money, is the prior month-end LIBOR plus a fixed rate of 1.00 percent.

XML

Revenue

3 Months Ended

Mar. 31, 2018

Revenue from Contract with Customer [Abstract]

Revenue

REVENUE

As described in Note 1, Duke Energy adopted Revenue from Contracts with Customers effective January 1, 2018, using the modified retrospective method of adoption which does not require restatement of prior year reported results. No cumulative effect adjustment was recorded as the vast majority of Duke Energy’s revenues are at-will and without a defined contractual term. Additionally, comparative disclosures for 2018 operating results with the previous revenue recognition rules are not applicable as Duke Energy’s revenue recognition has not materially changed as a result of the new standard.

Duke Energy recognizes revenue consistent with amounts billed under tariff offerings or at contractually agreed upon rates based on actual physical delivery of electric or natural gas service, including estimated volumes delivered when billings have not yet occurred. As such, the majority of Duke Energy’s revenues have fixed pricing based on the contractual terms of the published tariffs, with variability in expected cash flows attributable to the customer’s volumetric demand and ultimate quantities of energy or natural gas supplied and used during the billing period. The stand-alone selling price of related sales are designed to support recovery of prudently incurred costs and an appropriate return on invested assets and are primarily governed by published tariff rates or contractual agreements approved by relevant regulatory bodies. As described in Note 1, certain excise taxes and franchise fees levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis as part of revenues. Duke Energy elects to account for all other taxes net of revenues.

Performance obligations are satisfied over time as energy or natural gas is delivered and consumed with billings generally occurring monthly and related payments due within 30 days, depending on regulatory requirements. In no event does the timing between payment and delivery of the goods and services exceed one year. Using this output method for revenue recognition provides a faithful depiction of the transfer of electric and natural gas service as customers obtain control of the commodity and benefit from its use at delivery. Additionally, Duke Energy has an enforceable right to consideration for energy or natural gas delivered at any discrete point in time, and will recognize revenue at an amount that reflects the consideration to which Duke Energy is entitled for the energy or natural gas delivered.

As described above, the majority of Duke Energy’s tariff revenues are at-will and, as such, related contracts with customers have an expected duration of one year or less and will not have future performance obligations for disclosure. Additionally, other long-term revenue streams, including wholesale contracts, generally provide services that are part of a single performance obligation, the delivery of electricity or natural gas. As such, other than material fixed consideration under long-term contract, related disclosures for future performance obligations are also not applicable.

Duke Energy earns substantially all of its revenues through its reportable segments, Electric Utilities and Infrastructure, Gas Utilities and Infrastructure and Commercial Renewables.

Electric Utilities and Infrastructure

Electric Utilities and Infrastructure earns the majority of its revenues through retail and wholesale electric service through the generation, transmission, distribution and sale of electricity. Duke Energy generally provides retail and wholesale electric service customers with their full electric load requirements or with supplemental load requirements when the customer has other sources of electricity.

Retail electric service is generally marketed throughout Duke Energy's electric service territory through standard service offers. The standard service offers are through tariffs determined by regulators in Duke Energy's regulated service territory. Each tariff, which is assigned to customers based on customer class, has multiple components such as an energy charge, a demand charge, a basic facilities charge, and applicable riders. Duke Energy considers each of these components to be aggregated into a single performance obligation for providing electric service, or in the case of distribution only customers in Duke Energy Ohio, for delivering electricity. Electricity is considered a single performance obligation satisfied over time consistent with the series guidance and is provided and consumed over the billing period (generally one month). Retail electric service is typically provided to at-will customers that can cancel service at any time, without a substantive penalty. Additionally, Duke Energy adheres to applicable regulatory requirements in each jurisdiction to ensure the collectability of amounts billed and appropriate mitigating procedures are followed when necessary. As such, revenue from contracts with customers for such contracts is equivalent to the electricity supplied and billed in that period (including estimated billings).

Wholesale electric service is generally provided under long-term contracts using cost-based pricing. FERC regulates costs that may be recovered from customers and the amount of return companies are permitted to earn. Wholesale contracts include both energy and demand charges. For full requirements contracts, Duke Energy considers both charges as a single performance obligation for providing integrated electric service. For contracts where energy and demand charges are considered separate performance obligations, energy and demand are each a distinct performance obligation under the series guidance and are satisfied as energy is delivered and stand-ready service is provided on a monthly basis. This service represents consumption over the billing period and revenue is recognized consistent with billings and unbilled estimates, which generally occur monthly. Contractual amounts owed are typically trued up annually based upon incurred costs in accordance with FERC published filings and the specific customer’s actual peak demand. Estimates of variable consideration related to potential additional billings or refunds owed are updated quarterly.

The majority of wholesale revenues are full requirements contracts where the customers purchase the substantial majority of their energy needs and do not have a fixed quantity of contractually required energy or capacity. As such, related forecasted revenues are considered optional purchases. Supplemental requirements contracts that include contracted blocks of energy and capacity at contractually fixed prices have the following estimated remaining performance obligations:

	Remaining Performance Obligations
(in millions)	2018		2019		2020		2021		2022		Thereafter		Total
Progress Energy	$	69	$	112	$	121	$	80	$	82	$	81	$	545
Duke Energy Progress	7		9		9		9		9		18		61
Duke Energy Florida	62		103		112		71		73		63		484
Duke Energy Indiana	6		9		10		5		—		—		30

Revenues for block sales are recognized monthly as energy is delivered and stand-ready service is provided, consistent with invoiced amounts and unbilled estimates.

Gas Utilities and Infrastructure

Gas Utilities and Infrastructure earns its revenue through retail and wholesale natural gas service through the transportation, distribution and sale of natural gas. Duke Energy generally provides retail and wholesale natural gas service customers with all natural gas load requirements. Additionally, while natural gas can be stored, substantially all natural gas provided by Duke Energy is consumed by customers simultaneously with receipt of delivery.

Retail natural gas service is marketed throughout Duke Energy's natural gas service territory using published tariff rates. The tariff rates are established by regulators in Duke Energy's service territories. Each tariff, which is assigned to customers based on customer class, have multiple components, such as a commodity charge, demand charge, customer or monthly charge, and transportation costs. Duke Energy considers each of these components to be aggregated into a single performance obligation for providing natural gas service. For contracts where Duke Energy provides all of the customer’s natural gas needs, the delivery of natural gas is considered a single performance obligation satisfied over time, and revenue is recognized monthly based on billings and unbilled estimates as service is provided and the commodity is consumed over the billing period. Additionally, natural gas service is typically at-will and customers can cancel service at any time, without a substantive penalty. Duke Energy also adheres to applicable regulatory requirements to ensure the collectability of amounts billed and receivable and appropriate mitigating procedures are followed when necessary.

Certain long-term individually negotiated contracts exist to provide natural gas service. These contracts are regulated and approved by state commissions. The negotiated contracts have multiple components, including a natural gas and a demand charge, similar to retail natural gas contracts. Duke Energy considers each of these components to be a single performance obligation for providing natural gas service. This service represents consumption over the billing period, generally one month.

Fixed capacity payments under long-term contracts for the Gas segment include minimum margin contracts and supply arrangements with municipalities and power generation facilities. Revenues for related sales are recognized monthly as natural gas is delivered and stand-ready service is provided, consistent with invoiced amounts and unbilled estimates. Estimated remaining performance obligations are as follows:

	Remaining Performance Obligations
(in millions)	2018		2019		2020		2021		2022		Thereafter		Total
Piedmont	$	55	$	72	$	70	$	65	$	64	$	482	$	808

Commercial Renewables

Commercial Renewables earns the majority of its revenues through long-term PPAs and generally sells all of its wind and solar facility output, electricity and Renewable Energy Credits (RECs) to customers. The majority of these PPAs have historically been accounted for as leases. For PPAs that are not accounted for as leases, the delivery of electricity and the delivery of RECs are considered separate performance obligations.

The delivery of electricity is a performance obligation satisfied over time and represents generation and consumption of the electricity over the billing period, generally one month. The delivery of RECs is a performance obligation satisfied at a point in time and represents delivery of each REC generated by the wind or solar facility. The majority of self-generated RECs are bundled with energy in Duke Energy’s contracts and, as such, related revenues are recognized as energy is generated and delivered as that pattern is consistent with Duke Energy’s performance. Commercial Renewables recognizes revenue based on the energy generated and billed for the period, generally one month, at contractual rates (including estimated billings) according to the invoice practical expedient. Amounts are typically due within 30 days of invoice.

Other

The remainder of Duke Energy’s operations is presented as Other, which does not include material revenues from contracts with customers.

Disaggregated Revenues

For the Electric and Gas segments, revenue by customer class is most meaningful to Duke Energy as each respective customer class collectively represents unique customer expectations of service, generally has different energy and demand requirements, and operates under tailored, regulatory approved pricing structures. Additionally, each customer class is impacted differently by weather and a variety of economic factors including the level of population growth, economic investment, employment levels, and regulatory activities in each of Duke Energy’s jurisdictions. As such, analyzing revenues disaggregated by customer class allows Duke Energy to understand the nature, amount, timing, and uncertainty of revenue and cash flows arising from contracts with customers. For the Commercial Renewables segment, the majority of revenues from contracts with customers are from selling all of the unit-contingent output at contractually defined pricing under long-term PPAs with consistent expectations regarding the timing and certainty of cash flows. Disaggregated revenues are presented as follows:

	Three Months Ended March 31, 2018
			Duke				Duke		Duke		Duke		Duke
(in millions)	Duke		Energy		Progress		Energy		Energy		Energy		Energy
By market or type of customer	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Electric Utilities and Infrastructure
Residential	$	2,350	$	781	$	1,112	$	516	$	595	$	180	$	278	$	—
General	1,375		472		631		299		333		96		178		—
Industrial	664		255		208		145		62		30		173		—
Wholesale	633		119		446		397		50		—		68		—
Other revenues	139		67		129		85		43		14		17		—
Total Electric Utilities and Infrastructure revenue from contracts with customers	$	5,161	$	1,694	$	2,526	$	1,442	$	1,083	$	320	$	714	$	—
Gas Utilities and Infrastructure
Residential	$	413	$	—	$	—	$	—	$	—	$	111	$	—	$	302
Commercial	201		—		—		—		—		49		—		152
Industrial	48		—		—		—		—		7		—		41
Power Generation	—		—		—		—		—		—		—		13
Other revenues	55		—		—		—		—		6		—		49
Total Gas Utilities and Infrastructure revenue from contracts with customers	$	717	$	—	$	—	$	—	$	—	$	173	$	—	$	557
Commercial Renewables
Revenue from contracts with customers	$	33	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Other
Revenue from contracts with customers	$	17	$	—	$	—	$	—	$	—	$	14	$	—	$	—
Total revenue from contracts with customers	$	5,928	$	1,694	$	2,526	$	1,442	$	1,083	$	507	$	714	$	557
Other revenue sources (a)	$	207	$	69	$	50	$	18	$	32	$	17	$	17	$	(4	)
Total revenues	$	6,135	$	1,763	$	2,576	$	1,460	$	1,115	$	524	$	731	$	553

(a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Piedmont has regulatory mechanisms that periodically provide rate adjustments to refund any over-collection or to recover any under-collection of margin.

IMPACT OF WEATHER AND THE TIMING OF BILLING PERIODS

Revenues and costs are influenced by seasonal weather patterns. Peak sales of electricity occur during the summer and winter months, which results in higher revenue and cash flows during these periods. By contrast, lower sales of electricity occur during the spring and fall, allowing for scheduled plant maintenance. Residential and general service customers are more impacted by weather than industrial customers. Estimated weather impacts are based on actual current period weather compared to normal weather conditions. Normal weather conditions are defined as the long-term average of actual historical weather conditions. Heating-degree days measure the variation in weather based on the extent the average daily temperature falls below a base temperature. Cooling-degree days measure the variation in weather based on the extent the average daily temperature rises above the base temperature. Each degree of temperature below the base temperature counts as one heating-degree day and each degree of temperature above the base temperature counts as one cooling-degree day.

The estimated impact of weather on earnings for Electric Utilities and Infrastructure is based on the temperature variances from a normal condition and customers' historic usage patterns. The methodology used to estimate the impact of weather does not consider all variables that may impact customer response to weather conditions, such as humidity in the summer or wind chill in the winter. The precision of this estimate may also be impacted by applying long-term weather trends to shorter-term periods.

Gas Utilities and Infrastructure's costs and revenues are influenced by seasonal patterns due to peak natural gas sales occurring during the winter months as a result of space heating requirements. Residential customers are the most impacted by weather. There are certain regulatory mechanisms for the North Carolina, South Carolina, Tennessee, and Ohio service territories that normalize the margins collected from certain customer classes during the winter. In North Carolina, rate design provides protection from both weather and other usage variations such as conservation, while South Carolina and Tennessee revenues are adjusted solely based on weather. Ohio primarily employs a fixed charge each month regardless of the season and usage.

UNBILLED REVENUE

Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy or natural gas delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes, timing of rendering customer bills and meter reading schedules, and the impact of weather normalization or margin decoupling mechanisms.

Unbilled revenues are included within Receivables and Receivables of variable interest entities (VIEs) on the Condensed Consolidated Balance Sheets as shown in the following table.

(in millions)	March 31, 2018		December 31, 2017
Duke Energy	$	823	$	944
Duke Energy Carolinas	310		342
Progress Energy	237		228
Duke Energy Progress	167		143
Duke Energy Florida	70		85
Duke Energy Ohio	2		4
Duke Energy Indiana	24		21
Piedmont	45		86

Additionally, Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, CRC and accounts for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana. See Note 11 for further information. These receivables for unbilled revenues are shown in the table below.

(in millions)	March 31, 2018		December 31, 2017
Duke Energy Ohio	$	67	$	104
Duke Energy Indiana	108		132

XML

Common Stock

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Common Stock

COMMON STOCK

Basic Earnings Per Share (EPS) is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the diluted weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as stock options and equity forward sale agreements, were exercised or settled. Duke Energy’s participating securities are restricted stock units that are entitled to dividends declared on Duke Energy common stock during the restricted stock unit’s vesting periods.

The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted average number of common shares outstanding to the diluted weighted average number of common shares outstanding.

	Three Months Ended March 31,
(in millions, except per-share amounts)	2018		2017
Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities	$	619	$	715
Weighted average shares outstanding – basic	701		700
Weighted average shares outstanding – diluted	701		700
Earnings per share from continuing operations attributable to Duke Energy common stockholders
Basic	$	0.88	$	1.02
Diluted	$	0.88	$	1.02
Potentially dilutive items excluded from the calculation(a)	2		2
Dividends declared per common share	$	0.89	$	0.855

(a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met.

Equity Forwards

On February 20, 2018, Duke Energy filed a prospectus supplement and executed an Equity Distribution Agreement (the EDA) under which it may sell up to $1 billion of its common stock through an at-the-market offering program, including an equity forward sales component. The EDA was entered into with Wells Fargo Securities, LLC, Citigroup Global Markets Inc., and J.P. Morgan Securities LLC (the Agents). Under the terms of the EDA, Duke Energy may issue and sell, through either of the Agents, shares of common stock through September 23, 2019. There were no transactions under the EDA during the three months ended March 31, 2018.

Separately, in March 2018, Duke Energy marketed an equity offering of 21.3 million shares of common stock through an Underwriting Agreement with Credit Suisse Securities (USA) LLC, J.P. Morgan Securities LLC, Barclays Capital Inc. and Goldman Sachs & Co. LLC, as representatives of several underwriters, Credit Suisse Capital LLC and J.P. Morgan Securities LLC as Forward Sellers, and Credit Suisse Capital LLC and JPMorgan Chase National Bank Associate, acting as forward purchasers. In connection with the offering, Duke Energy entered into equity forward sale agreements with Credit Suisse Securities (USA) LLC as Agent for Credit Suisse Capital LLC and J.P. Morgan Chase Bank, National Association. No amounts have or will be recorded in Duke Energy's Condensed Consolidated Financial Statements with respect to the equity offering until settlements of the Equity Forwards occur, which is expected by December 31, 2018. The Equity Forwards require Duke Energy to either physically settle the transactions by issuing 21.3 million shares in exchange for net proceeds at the then-applicable forward sale price specified by the agreements (initially $74.07 per share), or net settle in whole or in part through the delivery or receipt of cash or shares. If Duke Energy had elected to net share settle the contract as of March 31, 2018, Duke Energy would have been required to deliver 0.9 million shares. The initial forward sale price will be subject to adjustment on a daily basis based on a floating interest rate factor and will decrease by other fixed amounts specified in the relevant forward sale agreement. Until settlement of the Equity Forwards, earnings per share dilution resulting from the agreements, if any, will be determined under the treasury stock method. Share dilution occurs when the average market price of Duke Energy's stock is higher than the average forward sales price.

Common Stock

COMMON STOCK

Basic Earnings Per Share (EPS) is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the diluted weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as stock options and equity forward sale agreements, were exercised or settled. Duke Energy’s participating securities are restricted stock units that are entitled to dividends declared on Duke Energy common stock during the restricted stock unit’s vesting periods.

The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted average number of common shares outstanding to the diluted weighted average number of common shares outstanding.

	Three Months Ended March 31,
(in millions, except per-share amounts)	2018		2017
Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities	$	619	$	715
Weighted average shares outstanding – basic	701		700
Weighted average shares outstanding – diluted	701		700
Earnings per share from continuing operations attributable to Duke Energy common stockholders
Basic	$	0.88	$	1.02
Diluted	$	0.88	$	1.02
Potentially dilutive items excluded from the calculation(a)	2		2
Dividends declared per common share	$	0.89	$	0.855

(a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met.

Equity Forwards

On February 20, 2018, Duke Energy filed a prospectus supplement and executed an Equity Distribution Agreement (the EDA) under which it may sell up to $1 billion of its common stock through an at-the-market offering program, including an equity forward sales component. The EDA was entered into with Wells Fargo Securities, LLC, Citigroup Global Markets Inc., and J.P. Morgan Securities LLC (the Agents). Under the terms of the EDA, Duke Energy may issue and sell, through either of the Agents, shares of common stock through September 23, 2019. There were no transactions under the EDA during the three months ended March 31, 2018.

Separately, in March 2018, Duke Energy marketed an equity offering of 21.3 million shares of common stock through an Underwriting Agreement with Credit Suisse Securities (USA) LLC, J.P. Morgan Securities LLC, Barclays Capital Inc. and Goldman Sachs & Co. LLC, as representatives of several underwriters, Credit Suisse Capital LLC and J.P. Morgan Securities LLC as Forward Sellers, and Credit Suisse Capital LLC and JPMorgan Chase National Bank Associate, acting as forward purchasers. In connection with the offering, Duke Energy entered into equity forward sale agreements with Credit Suisse Securities (USA) LLC as Agent for Credit Suisse Capital LLC and J.P. Morgan Chase Bank, National Association. No amounts have or will be recorded in Duke Energy's Condensed Consolidated Financial Statements with respect to the equity offering until settlements of the Equity Forwards occur, which is expected by December 31, 2018. The Equity Forwards require Duke Energy to either physically settle the transactions by issuing 21.3 million shares in exchange for net proceeds at the then-applicable forward sale price specified by the agreements (initially $74.07 per share), or net settle in whole or in part through the delivery or receipt of cash or shares. If Duke Energy had elected to net share settle the contract as of March 31, 2018, Duke Energy would have been required to deliver 0.9 million shares. The initial forward sale price will be subject to adjustment on a daily basis based on a floating interest rate factor and will decrease by other fixed amounts specified in the relevant forward sale agreement. Until settlement of the Equity Forwards, earnings per share dilution resulting from the agreements, if any, will be determined under the treasury stock method. Share dilution occurs when the average market price of Duke Energy's stock is higher than the average forward sales price.

XML

Stock-Based Compensation

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Stock-Based Compensation

STOCK-BASED COMPENSATION

For employee awards, equity classified stock-based compensation cost is measured at the service inception date or the grant date, based on the estimated achievement of certain performance metrics or the fair value of the award, and is recognized as expense or capitalized as a component of property, plant and equipment over the requisite service period.

Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense and stock-based compensation costs capitalized are included in the following table.

	Three Months Ended
	March 31,
(in millions)	2018		2017
Restricted stock unit awards	$	10	$	8
Performance awards	7		7
Pretax stock-based compensation cost	$	17	$	15
Tax benefit associated with stock-based compensation expense	$	4	$	5
Stock-based compensation costs capitalized	1		1

XML

Employee Benefit Plans

3 Months Ended

Mar. 31, 2018

Retirement Benefits [Abstract]

Employee Benefit Plans

EMPLOYEE BENEFIT PLANS

DEFINED BENEFIT RETIREMENT PLANS

Duke Energy maintains, and the Subsidiary Registrants participate in, qualified and non-qualified, non-contributory defined benefit retirement plans. Duke Energy’s policy is to fund amounts on an actuarial basis to provide assets sufficient to meet benefit payments to be paid to plan participants. The following table includes information related to the Duke Energy Registrants' contributions to its qualified defined benefit pension plans.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Total anticipated 2018 contributions	$	148	$	46	$	45	$	25	$	20	$	—	$	8	$	7
Contributions made during the three months ended March 31, 2018	141		46		45		25		20		—		8		—
Remaining estimated 2018 contributions	$	7	$	—	$	—	$	—	$	—	$	—	$	—	$	7

Duke Energy did not make any contributions to its qualified defined benefit pension plans during the three months ended March 31, 2017.

Duke Energy uses a December 31 measurement date for its defined benefit retirement plan assets and obligations.

Components of Net Periodic Benefit Costs

The tables below present total net periodic benefit costs prior to capitalization of amounts reflected as Net property, plant and equipment on the Condensed Consolidated Balance Sheets. Only the service cost component of net periodic benefit costs is eligible to be capitalized. The remaining non-capitalized portions of net periodic benefit costs are classified as either: (1) service cost, which is recorded in Operations, maintenance and other on the Condensed Consolidated Statements of Operations; or as (2) components of non-service cost, which is recorded in Other income and expenses, net on the Condensed Consolidated Statements of Operations. See Note 1 for further information on impacts of the retirement benefits accounting standard adopted by Duke Energy on January 1, 2018.

Pension and other post-retirement benefit costs presented in the tables below for the Subsidiary Registrants are amounts allocated from Duke Energy for the employees of the respective Subsidiary Registrants. The Condensed Consolidated Statements of Operations of the Subsidiary Registrants also include allocated net periodic benefit costs for their proportionate share of pension and post-retirement benefit costs related to employees of the Duke Energy shared services affiliate. However, in the tables below these amounts are only presented in the Duke Energy column. For additional information on the corporate governance and shared service expenses allocated from the Duke Energy shared service affiliate, see Note 7.

QUALIFIED PENSION PLANS

The following tables include the components of net periodic pension costs for qualified pension plans.

	Three Months Ended March 31, 2018
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	45		$	15		$	13		$	7		$	5		$	1		$	2		$	2
Interest cost on projected benefit obligation	75			18			24			11			13			5			6			3
Expected return on plan assets	(140		)	(37		)	(45		)	(21		)	(23		)	(7		)	(10		)	(6		)
Amortization of actuarial loss	33			7			11			5			6			1			2			3
Amortization of prior service credit	(8		)	(2		)	(1		)	—			—			—			—			(3		)
Net periodic pension costs	$	5		$	1		$	2		$	2		$	1		$	—		$	—		$	(1	)

	Three Months Ended March 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	40		$	12		$	12		$	6		$	5		$	1		$	2		$	3
Interest cost on projected benefit obligation	82			20			25			12			13			5			7			3
Expected return on plan assets	(136		)	(35		)	(43		)	(21		)	(21		)	(7		)	(11		)	(6		)
Amortization of actuarial loss	36			8			14			6			7			1			3			3
Amortization of prior service credit	(6		)	(2		)	(1		)	—			—			—			—			(1		)
Other	2			—			1			—			—			—			—			—
Net periodic pension costs	$	18		$	3		$	8		$	3		$	4		$	—		$	1		$	2

NON-QUALIFIED PENSION PLANS

Net periodic pension costs for non-qualified pension plans were not material for the three months ended March 31, 2018 and 2017.

OTHER POST-RETIREMENT BENEFIT PLANS

Duke Energy provides, and the Subsidiary Registrants participate in, some health care and life insurance benefits for retired employees on a contributory and non-contributory basis.

The following tables include the components of net periodic other post-retirement benefit costs.

	Three Months Ended March 31, 2018
				Duke						Duke		Duke			Duke		Duke
	Duke			Energy			Progress			Energy		Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress		Florida			Ohio		Indiana		Piedmont
Service cost	$	1		$	—		$	—		$	—	$	—		$	—	$	—	$	—
Interest cost on accumulated post-retirement benefit obligation	7			2			4			1		1			—		1		—
Expected return on plan assets	(2		)	(2		)	—			—		—			—		—		—
Amortization of actuarial loss	1			—			—			—		—			—		1		—
Amortization of prior service credit	(5		)	(1		)	(2		)	—		(1		)	—		—		—
Net periodic other post-retirement benefit costs	$	2		$	(1	)	$	2		$	1	$	—		$	—	$	2	$	—

	Three Months Ended March 31, 2017
				Duke						Duke			Duke			Duke		Duke
	Duke			Energy			Progress			Energy			Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio		Indiana		Piedmont
Service cost	$	1		$	—		$	—		$	—		$	—		$	—	$	—	$	—
Interest cost on accumulated post-retirement benefit obligation	9			2			4			2			2			—		—		—
Expected return on plan assets	(3		)	(2		)	—			—			—			—		—		—
Amortization of actuarial loss (gain)	2			(1		)	5			3			2			—		—		—
Amortization of prior service credit	(29		)	(2		)	(21		)	(14		)	(8		)	—		—		—
Net periodic other post-retirement benefit costs	$	(20	)	$	(3	)	$	(12	)	$	(9	)	$	(4	)	$	—	$	—	$	—

EMPLOYEE SAVINGS PLAN

Duke Energy sponsors, and the Subsidiary Registrants participate in, an employee savings plan that covers substantially all employees. The following table includes employer contributions made by Duke Energy and expensed by the Subsidiary Registrants.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Three Months Ended March 31,
2018	$	70	$	23	$	19	$	13	$	6	$	1	$	3	$	4
2017	65		22		18		13		5		1		3		2

XML

Income Taxes

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Income Taxes

INCOME TAXES

Tax Act

On December 22, 2017, President Trump signed the Tax Act into law. Among other provisions, the Tax Act lowered the corporate federal income tax rate from 35 percent to 21 percent, limits interest deductions outside of regulated utility operations, requires the normalization of excess deferred taxes associated with property under the average rate assumption method as a prerequisite to qualifying for accelerated depreciation and repealed the federal manufacturing deduction. The Tax Act also repealed the corporate alternative minimum tax (AMT) and stipulates a refund of 50 percent of remaining AMT credit carryforwards (to the extent the credits exceed regular tax for the year) for tax years 2018, 2019 and 2020 with all remaining AMT credits to be refunded in tax year 2021.

At this time, AMT credits that are treated as refundable under the Tax Act are among the certain refundable tax credits that are subject to sequestration. During the three months ended March 31, 2018, the company has revised the December 31, 2017, estimate of the income tax effects of the Tax Act by recording a $76 million valuation allowance against these AMT credits based on additional interpretative guidance from the Internal Revenue Service related to the Tax Act. See Note 22 to the Consolidated Financial Statements in the Annual Report on Form 10-K/A for the year ended December 31, 2017, for information on the U.S. Securities and Exchange Commission staff's guidance on accounting for the Tax Act (Staff Accounting Bulletin No. 118, Income Tax Accounting Implications of the Tax Cuts and Jobs Act).

EFFECTIVE TAX RATES

The effective tax rates from continuing operations for each of the Duke Energy Registrants are included in the following table.

	Three Months Ended
	March 31,
	2018		2017
Duke Energy	22.5	%	32.4	%
Duke Energy Carolinas	22.0	%	35.4	%
Progress Energy	13.2	%	34.1	%
Duke Energy Progress	14.1	%	34.1	%
Duke Energy Florida	16.3	%	36.6	%
Duke Energy Ohio	32.4	%	35.4	%
Duke Energy Indiana	25.9	%	39.3	%
Piedmont	24.1	%	37.9	%

The decrease in the effective tax rate (ETR) for Duke Energy and the Subsidiary Registrants for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act partially offset by a valuation allowance against AMT credits discussed above.

The decrease in the ETR for Duke Energy Carolinas for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act.

The decrease in the ETR for Progress Energy for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act and the amortization of federal and state excess deferred taxes.

The decrease in the ETR for Duke Energy Progress for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act and the amortization of state excess deferred taxes.

The decrease in the ETR for Duke Energy Florida for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act and the amortization of federal excess deferred taxes.

The decrease in the ETR for Duke Energy Ohio for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act partially offset by tax levelization related to federal excess deferred taxes on a pretax loss for the three months ended March 31, 2018.

The decrease in the ETR for Duke Energy Indiana for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act.

The decrease in the ETR for Piedmont for the three months endedMarch 31, 2018, is primarily due to the lower statutory federal corporate tax rate under the Tax Act.

XML

Subsequent Events

3 Months Ended

Mar. 31, 2018

Subsequent Events [Abstract]

Subsequent Events

SUBSEQUENT EVENTS

For information on subsequent events related to regulatory matters, commitments and contingencies, debt and credit facilities and variable interest entities see Notes 3, 4, 5 and 11, respectively.

XML

Organization and Basis of Presentation (Policy)

3 Months Ended

Mar. 31, 2018

Policy Text Block [Line Items]

Basis of Presentation

BASIS OF PRESENTATION

These Condensed Consolidated Financial Statements have been prepared in accordance with generally accepted accounting principles (GAAP) in the U.S. for interim financial information and with the instructions to Form 10-Q and Regulation S-X. Accordingly, these Condensed Consolidated Financial Statements do not include all information and notes required by GAAP in the U.S. for annual financial statements. Since the interim Condensed Consolidated Financial Statements and Notes do not include all information and notes required by GAAP in the U.S. for annual financial statements, the Condensed Consolidated Financial Statements and other information included in this quarterly report should be read in conjunction with the Consolidated Financial Statements and Notes in the Duke Energy Registrants’ combined Annual Report on Form 10-K/A for the year ended December 31, 2017.

The information in these combined notes relates to each of the Duke Energy Registrants as noted in the Index to Combined Notes to Condensed Consolidated Financial Statements. However, none of the registrants make any representations as to information related solely to Duke Energy or the subsidiaries of Duke Energy other than itself.

These Condensed Consolidated Financial Statements, in the opinion of the respective companies’ management, reflect all normal recurring adjustments necessary to fairly present the financial position and results of operations of each of the Duke Energy Registrants. Amounts reported in Duke Energy’s interim Condensed Consolidated Statements of Operations and each of the Subsidiary Registrants’ interim Condensed Consolidated Statements of Operations and Comprehensive Income are not necessarily indicative of amounts expected for the respective annual periods due to effects of seasonal temperature variations on energy consumption, regulatory rulings, timing of maintenance on electric generating units, changes in mark-to-market valuations, changing commodity prices and other factors.

Consolidation

These Condensed Consolidated Financial Statements include, after eliminating intercompany transactions and balances, the accounts of the Duke Energy Registrants and subsidiaries where the respective Duke Energy Registrants have control. These Condensed Consolidated Financial Statements also reflect the Duke Energy Registrants’ proportionate share of certain jointly owned generation and transmission facilities.

Use of Estimates

In preparing financial statements that conform to GAAP, management must make estimates and assumptions that affect the reported amounts of assets and liabilities, the reported amounts of revenues and expenses, and the disclosure of contingent assets and liabilities at the date of the financial statements. Actual results could differ from those estimates.

Cash and Cash Equivalents, Restricted Cash and Cash Equivalents

CASH, CASH EQUIVALENTS AND RESTRICTED CASH

Duke Energy, Progress Energy and Duke Energy Florida have restricted cash balances related primarily to collateral assets, escrow deposits and variable interest entities (VIEs). See Note 11 for additional information. Restricted cash amounts are included in Other within Current Assets and Other Noncurrent Assets.

Inventory

INVENTORY

Inventory is used for operations and is recorded primarily using the average cost method. Inventory related to regulated operations is valued at historical cost. Inventory related to nonregulated operations is valued at the lower of cost or market. Materials and supplies are recorded as inventory when purchased and subsequently charged to expense or capitalized to property, plant and equipment when installed. Inventory, including excess or obsolete inventory, is written-down to the lower of cost or market value. Once inventory has been written-down, it creates a new cost basis for the inventory that is not subsequently written-up.

New Accounting Standards

NEW ACCOUNTING STANDARDS

The new accounting standards adopted for 2018 and 2017 had no material impact on the presentation or results of operations, cash flows or financial position of the Duke Energy Registrants. While immaterial, adoption of the following accounting standards had the most significant impact on the Duke Energy results of operations, cash flows and financial position for the three months endedMarch 31, 2018.

Revenue from Contracts with Customers. In May 2014, the Financial Accounting Standards Board (FASB) issued revised accounting guidance for revenue recognition from contracts with customers. The core principle of this guidance is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration expected in exchange for those goods or services. The amendments also required disclosure of sufficient information to allow users to understand the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. The majority of Duke Energy’s revenue is in scope of the new guidance. Other revenue arrangements, such as alternative revenue programs and certain purchase power agreements (PPAs) and lighting tariffs accounted for as leases, are excluded from the scope of this guidance and, therefore, are accounted for and evaluated for separate presentation and disclosure under other relevant accounting guidance.

Duke Energy elected the modified retrospective method of adoption effective January 1, 2018. Under the modified retrospective method of adoption, prior year reported results are not restated. Adoption of this standard did not result in a material change in the timing or pattern of revenue recognition and a cumulative-effect adjustment was not recorded at January 1, 2018. Duke Energy utilized certain practical expedients including applying this guidance to open contracts at the date of adoption, expensing costs to obtain a contract where the amortization period of the asset would have been one year or less, ignoring the effects of a significant financing when the period between transfer of the good or service and payment is one year or less and recognizing revenues for certain contracts under the invoice practical expedient, which allows revenue recognition to be consistent with invoiced amounts (including estimated billings) provided certain criteria are met, including consideration of whether the invoiced amounts reasonably represent the value provided to customers.

In preparation for adoption, Duke Energy identified material revenue streams and reviewed representative contracts and tariffs, including those associated with certain long-term customer contracts such as wholesale contracts, PPAs, and other customer arrangements. Duke Energy also monitored the activities of the power and utilities industry revenue recognition task force and has reviewed published positions on specific industry issues to evaluate the impact, if any, on Duke Energy’s specific contracts and conclusions.

Duke Energy applied the available practical expedient to portfolios of tariffs and contracts with similar characteristics. The vast majority of sales, including energy provided to retail customers, are from tariff offerings that provide natural gas or electricity without a defined contractual term ("at-will"). In most circumstances, revenue from contracts with customers is equivalent to the electricity or natural gas supplied and billed in that period (including estimated billings). As such, adoption of the new rules did not result in a shift in the timing or pattern of revenue recognition for such sales. While there have been changes to the captions and descriptions of revenues in Duke Energy’s financial statements, the most significant impact as a result of adopting the standard are additional disclosures around the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. See Note 12 for further information.

Financial Instruments Classification and Measurement. In January 2018, Duke Energy adopted FASB guidance, which revised the classification and measurement of certain financial instruments. The adopted guidance changes the presentation of realized and unrealized gains and losses in certain equity securities that were previously recorded in accumulated other comprehensive income (AOCI). These gains and losses are now recorded in net income. An entity's equity investments that are accounted for under the equity method of accounting are not included within the scope of the new guidance. This guidance had a minimal impact on the Duke Energy Registrant's Condensed Consolidated Statements of Operations and Comprehensive Income as changes in the fair value of most of the Duke Energy Registrants' equity securities are deferred as regulatory assets or liabilities pursuant to accounting guidance for regulated operations. The resulting adjustment of unrealized gains and losses in AOCI to retained earnings was immaterial. The primary impact to Duke Energy as a result of implementing this guidance is adding disclosure requirements to present separately the financial assets and financial liabilities by measurement category and form of financial asset. See Notes 9 and 10 for further information.

Statement of Cash Flows. In November 2016, the FASB issued revised accounting guidance to reduce diversity in practice for the presentation and classification of restricted cash on the Condensed Consolidated Statements of Cash Flows. Under the updated guidance, restricted cash and restricted cash equivalents are included within beginning-of-period and end-of-period cash and cash equivalents on the Condensed Consolidated Statements of Cash Flows. Duke Energy adopted this guidance on January 1, 2018. The guidance has been applied using a retrospective transition method to each period presented. The adoption by Duke Energy of the revised guidance resulted in a change to the amount of Cash, cash equivalents and restricted cash explained when reconciling the beginning-of-period and end-of-period total amounts shown on the Condensed Consolidated Statements of Cash Flows. In addition, a reconciliation has been provided of Cash, cash equivalents and restricted cash reported within the Condensed Consolidated Balance Sheets that sums to the total of the same such amounts in the Condensed Consolidated Statements of Cash Flows. Prior to adoption, the Duke Energy Registrants reflected changes in noncurrent restricted cash within Cash Flows from Investing Activities and changes in current restricted cash within Cash Flows from Operating Activities on the Condensed Consolidated Statement of Cash Flows.

In August 2016, the FASB issued accounting guidance addressing diversity in practice for eight separate cash flow issues. The guidance requires entities to classify distributions received from equity method investees using either the cumulative earnings approach or the nature of the distribution approach. Duke Energy adopted this guidance on January 1, 2018, and has elected the nature of distribution approach. Duke Energy will categorize all distributions received based on legal documentation describing the nature of the activities generating the distribution. Cash inflows resulting in a return on investment (surplus) will be reflected in Cash Flows from Operating Activities on the Condensed Consolidated Statements of Cash Flows, whereas cash inflows resulting in a return of investment (capital) will be reflected in Cash Flows from Investing Activities on the Condensed Consolidated Statements of Cash Flows. The guidance has been applied using the retrospective transition method to each period presented. There are no changes to the Condensed Consolidated Statements of Cash Flows for the periods presented as a result of this accounting change.

Retirement Benefits. In March 2017, the FASB issued revised accounting guidance for the presentation of net periodic costs related to benefit plans. Previous guidance required the aggregation of all the components of net periodic costs on the Condensed Consolidated Statement of Operations and did not require the disclosure of the location of net periodic costs on the Condensed Consolidated Statement of Operations. Under the amended guidance, the service cost component of net periodic costs is included within Operating Income within the same line as other compensation expenses. All other components of net periodic costs are outside of Operating Income. In addition, the updated guidance permits only the service cost component of net periodic costs to be capitalized to Inventory or Property, Plant and Equipment. This represents a change from previous guidance, which permitted all components of net periodic costs to be eligible for capitalization.

Duke Energy adopted this guidance on January 1, 2018. Under previous guidance, Duke Energy presented the total non-capitalized net periodic costs within Operation, maintenance and other on the Condensed Consolidated Statement of Operations. The adoption of this guidance resulted in a retrospective change to reclassify the presentation of the non-service cost (benefit) components of net periodic costs to Other income and expenses. Duke Energy utilized the practical expedient for retrospective presentation. The change in components of net periodic costs eligible for capitalization is applicable prospectively. Since Duke Energy’s service cost component is greater than the total net periodic costs, the change results in increased capitalization of net periodic costs, higher Operation, maintenance and other and higher Other income and expenses. The resulting prospective impact to Duke Energy is an immaterial increase in Net Income. See Note 15 for further information.

For Duke Energy, the retrospective change resulted in higher Operation, maintenance and other and higher Other income and expenses, net, of $156 million, $131 million and $96 million for the years ended December 31, 2017, 2016 and 2015, respectively. There was no change to Net Income for these prior periods.

The following new Accounting Standards Updates (ASUs) have been issued, but have not yet been adopted by Duke Energy, as of March 31, 2018.

Leases. In February 2016, the FASB issued revised accounting guidance for leases. The core principle of this guidance is that a lessee should recognize the assets and liabilities that arise from leases on the balance sheet.

For Duke Energy, this guidance is effective for interim and annual periods beginning January 1, 2019. The guidance will be applied using a modified retrospective approach. Upon adoption, Duke Energy expects to elect certain of the practical expedients upon adoption:

Practical Expedient	Description
Package of transition practical expedients (for leases commenced prior to adoption date and must be adopted as a package)	Do not need to reassess whether any expired or existing contracts are/or contain leases, do not need to reassess the lease classification for any expired or existing leases and do not need to reassess initial direct costs for any existing leases.
Short-term lease expedient (elect by class of underlying asset)	Elect as an accounting policy to not apply the recognition requirements to short-term leases by asset class.
Lease and non-lease components (elect by class of underlying asset)	Duke Energy will likely elect as an accounting policy to not separate non-lease components from lease components and instead account for each lease and associated non-lease component as a single lease component.
Hindsight expedient (when determining lease term)	Elect to use hindsight to determine the lease term.
Easement expedient	Elect to carry forward current accounting treatment for existing easements.

Duke Energy is currently evaluating the financial statement impact of adopting this standard and is continuing to monitor industry implementation issues, including pipeline laterals, pole attachments and renewable PPAs. Other than an expected increase in assets and liabilities, the ultimate impact of the new standard has not yet been determined. Significant system enhancements, including additional processes and controls, will be required to facilitate the identification, tracking and reporting of potential leases based upon requirements of the new lease standard. Duke Energy has begun the implementation of a third-party software tool to help with the adoption and ongoing accounting under the new standard.

Environmental Costs

Costs are typically expensed as Operation, maintenance and other on the Condensed Consolidated Statements of Operations unless regulatory recovery of the costs is deemed probable.

Liabilities are recorded when losses become probable and are reasonably estimable.

Derivatives

For the Subsidiary Registrants, bulk power electricity and coal and natural gas purchases flow through fuel adjustment clauses, formula-based contracts or other cost-sharing mechanisms. Differences between the costs included in rates and the incurred costs, including undesignated derivative contracts, are largely deferred as regulatory assets or regulatory liabilities.

Duke Energy’s interest rate swaps for its regulated operations employ regulatory accounting. With regulatory accounting, the mark-to-market gains or losses on the swaps are deferred as regulatory liabilities or regulatory assets, respectively. Regulatory assets and liabilities are amortized consistent with the treatment of the related costs in the ratemaking process. The accrual of interest on the swaps is recorded as Interest Expense.

Investments

Unrealized gains and losses on all other AFS securities are included in other comprehensive income until realized, unless it is determined the carrying value of an investment is other-than-temporarily impaired. The Duke Energy Registrants analyze all investment holdings each reporting period to determine whether a decline in fair value should be considered other-than-temporary. If an OTTI exists, the unrealized credit loss is included in earnings.

As a result, the ability to hold investments in unrealized loss positions is outside the control of the Duke Energy Registrants. Accordingly, all unrealized losses associated with debt securities within the Investment Trusts are considered OTTIs and are recognized immediately and deferred to regulatory accounts where appropriate.

Earnings Per Share

Basic Earnings Per Share (EPS) is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the weighted average number of common shares outstanding during the period. Diluted EPS is computed by dividing net income attributable to Duke Energy common stockholders, as adjusted for distributed and undistributed earnings allocated to participating securities, by the diluted weighted average number of common shares outstanding during the period. Diluted EPS reflects the potential dilution that could occur if securities or other agreements to issue common stock, such as stock options and equity forward sale agreements, were exercised or settled.

Stock-based Compensation

For employee awards, equity classified stock-based compensation cost is measured at the service inception date or the grant date, based on the estimated achievement of certain performance metrics or the fair value of the award, and is recognized as expense or capitalized as a component of property, plant and equipment over the requisite service period.

Revenue

certain excise taxes and franchise fees levied by state or local governments are required to be paid even if not collected from the customer. These taxes are recognized on a gross basis as part of revenues. Duke Energy elects to account for all other taxes net of revenues.

Duke Energy recognizes revenue consistent with amounts billed under tariff offerings or at contractually agreed upon rates based on actual physical delivery of electric or natural gas service, including estimated volumes delivered when billings have not yet occurred.

Additionally, Duke Energy Ohio and Duke Energy Indiana sell, on a revolving basis, nearly all of their retail accounts receivable, including receivables for unbilled revenues, to an affiliate, CRC and accounts for the transfers of receivables as sales. Accordingly, the receivables sold are not reflected on the Condensed Consolidated Balance Sheets of Duke Energy Ohio and Duke Energy Indiana.

UNBILLED REVENUE

Unbilled revenues are recognized by applying customer billing rates to the estimated volumes of energy or natural gas delivered but not yet billed. Unbilled revenues can vary significantly from period to period as a result of seasonality, weather, customer usage patterns, customer mix, average price in effect for customer classes, timing of rendering customer bills and meter reading schedules, and the impact of weather normalization or margin decoupling mechanisms.

XML

Organization and Basis of Presentation (Tables)

3 Months Ended

Mar. 31, 2018

Organization And Basis Of Presentation [Line Items]

Schedule of Cash, Cash Equivalents and Restricted Cash

The following table presents the components of Cash, cash equivalents and restricted cash included in the Condensed Consolidated Balance Sheets.

	March 31, 2018						December 31, 2017
					Duke						Duke
	Duke		Progress		Energy		Duke		Progress		Energy
	Energy		Energy		Florida		Energy		Energy		Florida
Current Assets
Cash and cash equivalents	$	421	$	20	$	6	$	358	$	40	$	13
Other	149		13		13		138		40		40
Other Noncurrent Assets
Other	9		6		—		9		7		—
Total Cash, cash equivalents and restricted cash	$	579	$	39	$	19	$	505	$	87	$	53

Schedule of Utility Inventory

The components of inventory are presented in the tables below.

	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Materials and supplies	$	2,293	$	763	$	1,095	$	767	$	329	$	82	$	310	$	1
Coal	551		176		221		125		96		13		141		—
Natural gas, oil and other fuel	305		41		221		110		110		13		2		28
Total inventory	$	3,149	$	980	$	1,537	$	1,002	$	535	$	108	$	453	$	29

	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Materials and supplies	$	2,293	$	744	$	1,118	$	774	$	343	$	82	$	309	$	2
Coal	603		192		255		139		116		17		139		—
Natural gas, oil and other fuel	354		35		219		104		115		34		2		64
Total inventory	$	3,250	$	971	$	1,592	$	1,017	$	574	$	133	$	450	$	66

Schedule of Excise Taxes

Excise taxes accounted for on a gross basis within both Operating revenues and Property and other taxes on the Condensed Consolidated Statements of Operations were as follows.

	Three Months Ended March 31,
(in millions)	2018		2017
Duke Energy	$	99	$	91
Duke Energy Carolinas	8		9
Progress Energy	54		46
Duke Energy Progress	5		5
Duke Energy Florida	49		41
Duke Energy Ohio	30		28
Duke Energy Indiana	6		7
Piedmont	1		1

XML

Business Segments (Tables)

3 Months Ended

Mar. 31, 2018

Segment Reporting Information [Line Items]

Business Segment Data

Business segment information is presented in the following tables. Segment assets presented exclude intercompany assets.

	Three Months Ended March 31, 2018
	Electric		Gas				Total
	Utilities and		Utilities and		Commercial		Reportable
(in millions)	Infrastructure		Infrastructure		Renewables		Segments		Other			Eliminations			Consolidated
Unaffiliated revenues	$	5,315	$	702	$	101	$	6,118	$	17		$	—		$	6,135
Intersegment revenues	8		25		—		33		18			(51		)	—
Total revenues	$	5,323	$	727	$	101	$	6,151	$	35		$	(51	)	$	6,135
Segment income (loss)(a)(b)(c)	$	750	$	116	$	20	$	886	$	(266	)	$	—		$	620
Add back noncontrolling interests															2
Net income															$	622
Segment assets	$	120,021	$	11,396	$	4,265	$	135,682	$	2,682		$	177		$	138,541

	Three Months Ended March 31, 2017
	Electric		Gas				Total
	Utilities and		Utilities and		Commercial		Reportable
(in millions)	Infrastructure		Infrastructure		Renewables		Segments		Other			Eliminations			Consolidated
Unaffiliated revenues	$	4,939	$	648	$	128	$	5,715	$	14		$	—		$	5,729
Intersegment revenues	8		22		—		30		19			(49		)	—
Total revenues	$	4,947	$	670	$	128	$	5,745	$	33		$	(49	)	$	5,729
Segment income (loss)	$	635	$	133	$	25	$	793	$	(77	)	$	—		$	716
Add back noncontrolling interests															1
Net income															$	717

(a) Electric Utilities and Infrastructure includes regulatory charges related to NCUC orders and settlements. See Note 3 for additional information.

(b) Gas Utilities and Infrastructure includes an impairment of the investment in Constitution Pipeline Company, LLC (Constitution). See Note 3 for additional information.

(c) Other includes the loss on the sale of the retired Beckjord generating station (Beckjord) described below and a valuation allowance recorded against the alternative minimum tax credits subject to sequestration. See Note 16 for additional information on the valuation allowance.

Duke Energy Ohio [Member]

Segment Reporting Information [Line Items]

Business Segment Data

	Three Months Ended March 31, 2018
	Electric		Gas		Total
	Utilities and		Utilities and		Reportable
(in millions)	Infrastructure		Infrastructure		Segments		Other			Eliminations			Consolidated
Total revenues	$	336	$	174	$	510	$	14		$	—		$	524
Segment income (loss)/Net income (loss)(a)	33		34		67		(92		)	—			(25		)
Segment assets	$	5,165	$	2,709	$	7,874	$	25		$	(3	)	$	7,896

	Three Months Ended March 31, 2017
	Electric		Gas		Total
	Utilities and		Utilities and		Reportable
(in millions)	Infrastructure		Infrastructure		Segments		Other			Consolidated
Total revenues	$	337	$	170	$	507	$	11		$	518
Segment income (loss)/Net income (loss)	24		26		50		(8		)	42

(a) Other includes the loss on the sale of the retired Beckjord generating station described above.

XML

Regulatory Matters (Tables)

3 Months Ended

Mar. 31, 2018

Regulated Operations [Abstract]

Schedule of Potential Plant Retirements

The table below contains the net carrying value of generating facilities planned for retirement or included in recent IRPs as evaluated for potential retirement due to a lack of requisite environmental control equipment. Dollar amounts in the table below are included in Net property, plant and equipment on the Condensed Consolidated Balance Sheets as of March 31, 2018, and exclude capitalized asset retirement costs.

		Remaining Net
	Capacity	Book Value
	(in MW)	(in millions)
Duke Energy Carolinas
Allen Steam Station Units 1-3(a)	585	$	161
Progress Energy and Duke Energy Florida
Crystal River Units 1 and 2(b)	873	104
Duke Energy Indiana
Gallagher Units 2 and 4(c)	280	126
Total Duke Energy	1,738	$	391

(a) Duke Energy Carolinas will retire Allen Steam Station Units 1 through 3 by December 31, 2024, as part of the resolution of a lawsuit involving alleged New Source Review violations.

(b) Duke Energy Florida expects to retire these coal units by the end of 2018 to comply with environmental regulations.

(c) Duke Energy Indiana committed to either retire or stop burning coal at Gallagher Units 2 and 4 by December 31, 2022, as part of the settlement of Edwardsport IGCC matters.

XML

Commitments and Contingencies (Table)

3 Months Ended

Mar. 31, 2018

Valuation and Qualifying Accounts Disclosure [Line Items]

Schedule of Additional Possible Losses in Excess of Recorded Environmental Reserves

Additional losses in excess of recorded reserves that could be incurred for the stages of investigation, remediation and monitoring for environmental sites that have been evaluated at this time are not material except as presented in the table below.

(in millions)
Duke Energy	$	57
Duke Energy Carolinas	19
Duke Energy Ohio	30
Piedmont	2

Reserve for Environmental Costs [Member]

Valuation and Qualifying Accounts Disclosure [Line Items]

Schedule of Legal Reserves

The following tables contain information regarding reserves for probable and estimable costs related to the various environmental sites. These reserves are recorded in Accounts Payable within Current Liabilities and Other within Other Noncurrent Liabilities on the Condensed Consolidated Balance Sheets.

	Three Months Ended March 31, 2018
				Duke					Duke			Duke			Duke			Duke
	Duke			Energy		Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas		Energy			Progress			Florida			Ohio			Indiana		Piedmont
Balance at beginning of period	$	81		$	10	$	15		$	3		$	12		$	47		$	5	$	2
Provisions/adjustments	4			1		3			1			1			—			1		—
Cash reductions	(5		)	—		(2		)	(1		)	(1		)	(3		)	—		—
Balance at end of period	$	80		$	11	$	16		$	3		$	12		$	44		$	6	$	2

	Three Months Ended March 31, 2017
				Duke					Duke		Duke			Duke			Duke
	Duke			Energy		Progress			Energy		Energy			Energy			Energy
(in millions)	Energy			Carolinas		Energy			Progress		Florida			Ohio			Indiana			Piedmont
Balance at beginning of period	$	98		$	10	$	18		$	3	$	14		$	59		$	10		$	1
Provisions/adjustments	6			1		—			—		1			4			(1		)	1
Cash reductions	(6		)	—		(1		)	—		(1		)	(4		)	—			—
Balance at end of period	$	98		$	11	$	17		$	3	$	14		$	59		$	9		$	2

Legal Reserve [Member]

Valuation and Qualifying Accounts Disclosure [Line Items]

Schedule of Legal Reserves

The table below presents recorded reserves based on management’s best estimate of probable loss for legal matters, excluding asbestos-related reserves and the exit obligation related to the termination of an EPC contract discussed above. Reserves are classified on the Condensed Consolidated Balance Sheets in Other within Other Noncurrent Liabilities and Accounts payable and Other within Current Liabilities. The reasonably possible range of loss in excess of recorded reserves is not material, other than as described above.

(in millions)	March 31, 2018		December 31, 2017
Reserves for Legal Matters
Duke Energy	$	74	$	88
Duke Energy Carolinas	20		30
Progress Energy	51		55
Duke Energy Progress	10		13
Duke Energy Florida	24		24
Piedmont	2		2

XML

Debt and Credit Facilities (Tables)

3 Months Ended

Mar. 31, 2018

Debt Disclosure [Abstract]

Schedule of Long-term Debt Instruments

The following table summarizes significant debt issuances (in millions).

				Three Months Ended March 31, 2018
						Duke		Duke
	Maturity	Interest		Duke		Energy		Energy
Issuance Date	Date	Rate		Energy		(Parent)		Carolinas
Unsecured Debt
March 2018(a)	April 2025	3.950	%	$	250	$	250	$	—
First Mortgage Bonds
March 2018(b)	March 2023	3.050	%	500		—		500
March 2018(b)	March 2048	3.950	%	500		—		500
Total issuances				$	1,250	$	250	$	1,000

(a) Debt issued to pay down short-term debt.

(b) Debt issued to repay at maturity a $300 million first mortgage bond due April 2018, pay down intercompany short-term debt and for general corporate purposes.

The following table shows the significant components of Current Maturities of Long-Term Debt on the Condensed Consolidated Balance Sheets. The Duke Energy Registrants currently anticipate satisfying these obligations with cash on hand and proceeds from additional borrowings.

(in millions)	Maturity Date	Interest Rate			March 31, 2018
Unsecured Debt
Duke Energy (Parent)	June 2018	6.250	%		$	250
Duke Energy (Parent)	June 2018	2.100	%		500
Piedmont	December 2018	2.821	%	(b)	250
Progress Energy	March 2019	7.050	%		450
First Mortgage Bonds
Duke Energy Carolinas	April 2018	5.100	%		300
Duke Energy Florida	June 2018	5.650	%		500
Duke Energy Carolinas	November 2018	7.000	%		500
Duke Energy Progress	January 2019	5.300	%		600
Other(a)					601
Current maturities of long-term debt					$	3,951

(a)    Includes capital lease obligations, amortizing debt and small bullet maturities.

(b)    Debt issuance has a floating interest rate.

Schedule Of Line Of Credit Facilities

The table below includes the current borrowing sublimits and available capacity under the Master Credit Facility.

	March 31, 2018
				Duke			Duke			Duke			Duke			Duke			Duke
	Duke			Energy			Energy			Energy			Energy			Energy			Energy
(in millions)	Energy			(Parent)			Carolinas			Progress			Florida			Ohio			Indiana			Piedmont
Facility size(a)	$	8,000		$	2,650		$	1,550		$	1,250		$	800		$	450		$	600		$	700
Reduction to backstop issuances
Commercial paper(b)	(2,602		)	(1,281		)	(340		)	(464		)	—			(140		)	(282		)	(95		)
Outstanding letters of credit	(59		)	(50		)	(4		)	(2		)	(1		)	—			—			(2		)
Tax-exempt bonds	(81		)	—			—			—			—			—			(81		)	—
Coal ash set-aside	(500		)	—			(250		)	(250		)	—			—			—			—
Available capacity under the Master Credit Facility	$	4,758		$	1,319		$	956		$	534		$	799		$	310		$	237		$	603

(a) Represents the sublimit of each borrower.

(b) Duke Energy issued $625 million of commercial paper and loaned the proceeds through the money pool to Duke Energy Carolinas, Duke Energy Progress, Duke Energy Ohio and Duke Energy Indiana. The balances are classified as Long-Term Debt Payable to Affiliated Companies on the Condensed Consolidated Balance Sheets.

XML

Goodwill (Tables)

3 Months Ended

Mar. 31, 2018

Goodwill and Intangible Assets Disclosure [Abstract]

Goodwill By Reportable Operating Segment

The following table presents the goodwill by reportable operating segment included on Duke Energy's Condensed Consolidated Balance Sheets at March 31, 2018, and December 31, 2017.

	Electric Utilities		Gas Utilities		Commercial
(in millions)	and Infrastructure		and Infrastructure		Renewables			Total
Goodwill balance	$	17,379	$	1,924	$	122		$	19,425
Accumulated impairment charges	—		—		(29		)	(29		)
Goodwill, adjusted for accumulated impairment charges	$	17,379	$	1,924	$	93		$	19,396

XML

Related Party Transactions (Tables)

3 Months Ended

Mar. 31, 2018

Related Party Transaction [Line Items]

Schedule of Related Party Transactions, Other Revenue and Expense

Material amounts related to transactions with related parties included on the Condensed Consolidated Statements of Operations and Comprehensive Income are presented in the following table.

	Three Months Ended March 31,
(in millions)	2018		2017
Duke Energy Carolinas
Corporate governance and shared service expenses(a)	$	220	$	221
Indemnification coverages(b)	6		6
JDA revenue(c)	34		16
JDA expense(c)	54		31
Intercompany natural gas purchases(d)	4		1
Progress Energy
Corporate governance and shared service expenses(a)	$	191	$	170
Indemnification coverages(b)	8		10
JDA revenue(c)	54		31
JDA expense(c)	34		16
Intercompany natural gas purchases(d)	19		19
Duke Energy Progress
Corporate governance and shared service expenses(a)	$	118	$	100
Indemnification coverages(b)	3		4
JDA revenue(c)	54		31
JDA expense(c)	34		16
Intercompany natural gas purchases(d)	19		19
Duke Energy Florida
Corporate governance and shared service expenses(a)	$	73	$	70
Indemnification coverages(b)	5		6
Duke Energy Ohio
Corporate governance and shared service expenses(a)	$	89	$	92
Indemnification coverages(b)	1		1
Duke Energy Indiana
Corporate governance and shared service expenses(a)	$	101	$	95
Indemnification coverages(b)	2		2
Piedmont
Corporate governance and shared service expenses(a)	$	36	$	5
Indemnification coverages(b)	1		1
Intercompany natural gas sales(d)	23		20

(a) The Subsidiary Registrants are charged their proportionate share of corporate governance and other shared services costs, primarily related to human resources, employee benefits, information technology, legal and accounting fees, as well as other third-party costs. These amounts are primarily recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(b) The Subsidiary Registrants incur expenses related to certain indemnification coverages through Bison, Duke Energy’s wholly owned captive insurance subsidiary. These expenses are recorded in Operation, maintenance and other on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(c) Duke Energy Carolinas and Duke Energy Progress participate in a Joint Dispatch Agreement (JDA), which allows the collective dispatch of power plants between the service territories to reduce customer rates. Revenues from the sale of power and expenses from the purchase of power pursuant to the JDA are recorded in Operating Revenues and Fuel used in electric generation and purchased power, respectively, on the Condensed Consolidated Statements of Operations and Comprehensive Income.

(d) Piedmont provides long-term natural gas delivery service to certain Duke Energy Carolinas and Duke Energy Progress natural gas-fired generation facilities. Piedmont records the sales in Regulated natural gas revenues, and Duke Energy Carolinas and Duke Energy Progress record the related purchases in Fuel used in electric generation and purchased power on their respective Condensed Consolidated Statements of Operations and Comprehensive Income. The amounts are not eliminated in accordance with rate-based accounting regulations.

The following table presents expenses for the three months ended March 31, 2018, and 2017, which are included in Cost of natural gas on Piedmont's Condensed Consolidated Statements of Operations and Comprehensive Income.

		Three Months Ended March 31,
(in millions)	Type of expense	2018		2017
Cardinal	Transportation Costs	$	2	$	2
Pine Needle	Natural Gas Storage Costs	2		2
Hardy Storage	Natural Gas Storage Costs	2		2
Total		$	6	$	6

The following table includes the balance of intercompany income tax receivables and payables for the Subsidiary Registrants.

	Duke				Duke		Duke		Duke		Duke
	Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
March 31, 2018
Intercompany income tax receivable	$	—	$	183	$	13	$	9	$	—	$	—	$	—
Intercompany income tax payable	9		—		—		—		3		18		43
December 31, 2017
Intercompany income tax receivable	$	—	$	168	$	—	$	44	$	22	$	—	$	7
Intercompany income tax payable	44		—		21		—		—		35		—

XML

Derivatives and Hedging (Tables)

3 Months Ended

Mar. 31, 2018

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Notional Amounts of Outstanding Derivative Positions

The following table shows notional amounts of outstanding derivatives related to interest rate risk.

	March 31, 2018
			Duke				Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio
Cash flow hedges(a)	$	660	$	—	$	—	$	—	$	—	$	—
Undesignated contracts	527		—		500		250		250		27
Total notional amount	$	1,187	$	—	$	500	$	250	$	250	$	27

	December 31, 2017
			Duke				Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio
Cash flow hedges(a)	$	660	$	—	$	—	$	—	$	—	$	—
Undesignated contracts	927		400		500		250		250		27
Total notional amount	$	1,587	$	400	$	500	$	250	$	250	$	27

(a) Duke Energy includes amounts related to consolidated VIEs of $660 million as of March 31, 2018, and December 31, 2017.

The tables below include volumes of outstanding commodity derivatives. Amounts disclosed represent the absolute value of notional volumes of commodity contracts excluding NPNS. The Duke Energy Registrants have netted contractual amounts where offsetting purchase and sale contracts exist with identical delivery locations and times of delivery. Where all commodity positions are perfectly offset, no quantities are shown.

	March 31, 2018
		Duke		Duke	Duke	Duke
	Duke	Energy	Progress	Energy	Energy	Energy
	Energy	Carolinas	Energy	Progress	Florida	Indiana	Piedmont
Electricity (gigawatt-hours)	16	—	—	—	—	16	—
Natural gas (millions of dekatherms)	765	110	179	149	30	2	474

	December 31, 2017
		Duke		Duke	Duke	Duke
	Duke	Energy	Progress	Energy	Energy	Energy
	Energy	Carolinas	Energy	Progress	Florida	Indiana	Piedmont
Electricity (gigawatt-hours)	34	—	—	—	—	34	—
Natural gas (millions of dekatherms)	770	105	183	133	50	2	480

Location And Fair Value Of Derivatives Recognized in the Condensed Consolidated Balance Sheets

The following tables show the fair value and balance sheet location of derivative instruments. Although derivatives subject to master netting arrangements are netted on the Condensed Consolidated Balance Sheets, the fair values presented below are shown gross and cash collateral on the derivatives has not been netted against the fair values shown.

Derivative Assets	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	14	$	2	$	3	$	2	$	1	$	1	$	7	$	1
Noncurrent	1		—		—		—		—		—		—		—
Total Derivative Assets – Commodity Contracts	$	15	$	2	$	3	$	2	$	1	$	1	$	7	$	1
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	1	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	21		—		—		—		—		—		—		—
Total Derivative Assets – Interest Rate Contracts	$	22	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Total Derivative Assets	$	37	$	2	$	3	$	2	$	1	$	1	$	7	$	1

Derivative Liabilities	March 31, 2018
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	26	$	5	$	8	$	6	$	3	$	—	$	—	$	13
Noncurrent	140		6		15		6		—		—		—		119
Total Derivative Liabilities – Commodity Contracts	$	166	$	11	$	23	$	12	$	3	$	—	$	—	$	132
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	4	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	3		—		—		—		—		—		—		—
Not Designated as Hedging Instruments
Current	3		—		3		2		1		—		—		—
Noncurrent	14		—		11		7		3		4		—		—
Total Derivative Liabilities – Interest Rate Contracts	$	24	$	—	$	14	$	9	$	4	$	4	$	—	$	—
Total Derivative Liabilities	$	190	$	11	$	37	$	21	$	7	$	4	$	—	$	132

Derivative Assets	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	34	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Noncurrent	1		—		1		1		—		—		—		—
Total Derivative Assets – Commodity Contracts	$	35	$	2	$	3	$	2	$	1	$	1	$	27	$	2
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	1	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	15		—		—		—		—		—		—		—
Total Derivative Assets – Interest Rate Contracts	$	16	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Total Derivative Assets	$	51	$	2	$	3	$	2	$	1	$	1	$	27	$	2

Derivative Liabilities	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Commodity Contracts
Not Designated as Hedging Instruments
Current	$	36	$	6	$	18	$	8	$	10	$	—	$	—	$	11
Noncurrent	146		4		10		4		—		—		—		131
Total Derivative Liabilities – Commodity Contracts	$	182	$	10	$	28	$	12	$	10	$	—	$	—	$	142
Interest Rate Contracts
Designated as Hedging Instruments
Current	$	29	$	25	$	—	$	—	$	—	$	—	$	—	$	—
Noncurrent	6		—		—		—		—		—		—		—
Not Designated as Hedging Instruments
Current	1		—		1		—		—		1		—		—
Noncurrent	12		—		7		6		2		4		—		—
Total Derivative Liabilities – Interest Rate Contracts	$	48	$	25	$	8	$	6	$	2	$	5	$	—	$	—
Total Derivative Liabilities	$	230	$	35	$	36	$	18	$	12	$	5	$	—	$	142

Offsetting Assets

The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.

Derivative Assets	March 31, 2018
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	15		$	2		$	3		$	2		$	1	$	1	$	7	$	1
Gross amounts offset	(2		)	(1		)	(1		)	(1		)	—		—		—		—
Net amounts presented in Current Assets: Other	$	13		$	1		$	2		$	1		$	1	$	1	$	7	$	1
Noncurrent
Gross amounts recognized	$	22		$	—		$	—		$	—		$	—	$	—	$	—	$	—
Gross amounts offset	—			—			—			—			—		—		—		—
Net amounts presented in Other Noncurrent Assets: Other	$	22		$	—		$	—		$	—		$	—	$	—	$	—	$	—

Derivative Assets	December 31, 2017
			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	35	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Gross amounts offset	—		—		—		—		—		—		—		—
Net amounts presented in Current Assets: Other	$	35	$	2	$	2	$	1	$	1	$	1	$	27	$	2
Noncurrent
Gross amounts recognized	$	16	$	—	$	1	$	1	$	—	$	—	$	—	$	—
Gross amounts offset	—		—		—		—		—		—		—		—
Net amounts presented in Other Noncurrent Assets: Other	$	16	$	—	$	1	$	1	$	—	$	—	$	—	$	—

Offsetting Liabilities

Derivative Liabilities	December 31, 2017
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	66		$	31		$	19		$	8		$	10	$	1	$	—	$	11
Gross amounts offset	(3		)	(2		)	(2		)	(2		)	—		—		—		—
Net amounts presented in Current Liabilities: Other	$	63		$	29		$	17		$	6		$	10	$	1	$	—	$	11
Noncurrent
Gross amounts recognized	$	164		$	4		$	17		$	10		$	2	$	4	$	—	$	131
Gross amounts offset	(1		)	—			(1		)	(1		)	—		—		—		—
Net amounts presented in Other Noncurrent Liabilities: Other	$	163		$	4		$	16		$	9		$	2	$	4	$	—	$	131

Derivative Liabilities	March 31, 2018
				Duke						Duke			Duke		Duke		Duke
	Duke			Energy			Progress			Energy			Energy		Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida		Ohio		Indiana		Piedmont
Current
Gross amounts recognized	$	33		$	5		$	11		$	8		$	4	$	—	$	—	$	13
Gross amounts offset	(4		)	(2		)	(2		)	(2		)	—		—		—		—
Net amounts presented in Current Liabilities: Other	$	29		$	3		$	9		$	6		$	4	$	—	$	—	$	13
Noncurrent
Gross amounts recognized	$	157		$	6		$	26		$	13		$	3	$	4	$	—	$	119
Gross amounts offset	(1		)	—			(1		)	(1		)	—		—		—		—
Net amounts presented in Other Noncurrent Liabilities: Other	$	156		$	6		$	25		$	12		$	3	$	4	$	—	$	119

The following tables present the line items on the Condensed Consolidated Balance Sheets where derivatives are reported. Substantially all of Duke Energy's outstanding derivative contracts are subject to enforceable master netting arrangements. The gross amounts offset in the tables below show the effect of these netting arrangements on financial position, and include collateral posted to offset the net position. The amounts shown are calculated by counterparty. Accounts receivable or accounts payable may also be available to offset exposures in the event of bankruptcy. These amounts are not included in the tables below.

Derivative Contracts with Contingent Credit Features

The following tables show information with respect to derivative contracts that are in a net liability position and contain objective credit-risk-related payment provisions.

	March 31, 2018
			Duke				Duke		Duke
	Duke		Energy		Progress		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida
Aggregate fair value of derivatives in a net liability position	$	30	$	10	$	20	$	18	$	2
Fair value of collateral already posted	—		—		—		—		—
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	30		10		20		18		2

	December 31, 2017
			Duke				Duke		Duke
	Duke		Energy		Progress		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida
Aggregate fair value of derivatives in a net liability position	$	59	$	35	$	25	$	15	$	10
Fair value of collateral already posted	—		—		—		—		—
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	59		35		25		15		10

XML

Investments in Debt and Equity Securities (Tables)

3 Months Ended

Mar. 31, 2018

Schedule of Available-for-sale Securities [Line Items]

Debt Securities, Trading, and Equity Securities, FV-NI

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	143	$	—	$	—	$	115
Equity securities	2,751		38		4,857		2,805		27		4,914
Corporate debt securities	7		8		549		17		2		570
Municipal bonds	1		5		333		4		3		344
U.S. government bonds	6		18		1,014		11		7		1,027
Other debt securities	—		2		130		—		1		118
Total NDTF Investments	$	2,765	$	71	$	7,026	$	2,837	$	40	$	7,088
Other Investments
Cash and cash equivalents	$	—	$	—	$	15	$	—	$	—	$	15
Equity securities	57		—		130		59		—		123
Corporate debt securities	—		1		64		1		—		57
Municipal bonds	1		1		80		2		1		83
U.S. government bonds	—		1		51		—		—		41
Other debt securities	—		—		48		—		1		44
Total Other Investments	$	58	$	3	$	388	$	62	$	2	$	363
Total Investments	$	2,823	$	74	$	7,414	$	2,899	$	42	$	7,451

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Debt Securities, Available-for-sale

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	143	$	—	$	—	$	115
Equity securities	2,751		38		4,857		2,805		27		4,914
Corporate debt securities	7		8		549		17		2		570
Municipal bonds	1		5		333		4		3		344
U.S. government bonds	6		18		1,014		11		7		1,027
Other debt securities	—		2		130		—		1		118
Total NDTF Investments	$	2,765	$	71	$	7,026	$	2,837	$	40	$	7,088
Other Investments
Cash and cash equivalents	$	—	$	—	$	15	$	—	$	—	$	15
Equity securities	57		—		130		59		—		123
Corporate debt securities	—		1		64		1		—		57
Municipal bonds	1		1		80		2		1		83
U.S. government bonds	—		1		51		—		—		41
Other debt securities	—		—		48		—		1		44
Total Other Investments	$	58	$	3	$	388	$	62	$	2	$	363
Total Investments	$	2,823	$	74	$	7,414	$	2,899	$	42	$	7,451

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Available-for-sale Securities

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	143	$	—	$	—	$	115
Equity securities	2,751		38		4,857		2,805		27		4,914
Corporate debt securities	7		8		549		17		2		570
Municipal bonds	1		5		333		4		3		344
U.S. government bonds	6		18		1,014		11		7		1,027
Other debt securities	—		2		130		—		1		118
Total NDTF Investments	$	2,765	$	71	$	7,026	$	2,837	$	40	$	7,088
Other Investments
Cash and cash equivalents	$	—	$	—	$	15	$	—	$	—	$	15
Equity securities	57		—		130		59		—		123
Corporate debt securities	—		1		64		1		—		57
Municipal bonds	1		1		80		2		1		83
U.S. government bonds	—		1		51		—		—		41
Other debt securities	—		—		48		—		1		44
Total Other Investments	$	58	$	3	$	388	$	62	$	2	$	363
Total Investments	$	2,823	$	74	$	7,414	$	2,899	$	42	$	7,451

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	100
Due after one through five years	535
Due after five through 10 years	530
Due after 10 years	1,104
Total	$	2,269

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	19
Realized losses	13
AFS:
Realized gains	5
Realized losses	13

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	93
Realized losses	62

Duke Energy Carolinas [Member]

Schedule of Available-for-sale Securities [Line Items]

Debt Securities, Trading, and Equity Securities, FV-NI

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	32
Equity securities	1,502		20		2,669		1,531		12		2,692
Corporate debt securities	3		5		333		9		2		359
Municipal bonds	—		1		69		—		1		60
U.S. government bonds	2		11		494		3		4		503
Other debt securities	—		2		122		—		1		112
Total NDTF Investments	$	1,507	$	39	$	3,737	$	1,543	$	20	$	3,758

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Debt Securities, Available-for-sale

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	32
Equity securities	1,502		20		2,669		1,531		12		2,692
Corporate debt securities	3		5		333		9		2		359
Municipal bonds	—		1		69		—		1		60
U.S. government bonds	2		11		494		3		4		503
Other debt securities	—		2		122		—		1		112
Total NDTF Investments	$	1,507	$	39	$	3,737	$	1,543	$	20	$	3,758

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Available-for-sale Securities

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	50	$	—	$	—	$	32
Equity securities	1,502		20		2,669		1,531		12		2,692
Corporate debt securities	3		5		333		9		2		359
Municipal bonds	—		1		69		—		1		60
U.S. government bonds	2		11		494		3		4		503
Other debt securities	—		2		122		—		1		112
Total NDTF Investments	$	1,507	$	39	$	3,737	$	1,543	$	20	$	3,758

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	11
Due after one through five years	178
Due after five through 10 years	285
Due after 10 years	544
Total	$	1,018

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	10
Realized losses	5
AFS:
Realized gains	5
Realized losses	10

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	66
Realized losses	40

Progress Energy [Member]

Schedule of Available-for-sale Securities [Line Items]

Debt Securities, Trading, and Equity Securities, FV-NI

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	93	$	—	$	—	$	83
Equity securities	1,249		18		2,188		1,274		15		2,222
Corporate debt securities	4		3		216		8		—		211
Municipal bonds	1		4		264		4		2		284
U.S. government bonds	4		7		520		8		3		524
Other debt securities	—		—		8		—		—		6
Total NDTF Investments	$	1,258	$	32	$	3,289	$	1,294	$	20	$	3,330
Other Investments
Cash and cash equivalents	$	—	$	—	$	10	$	—	$	—	$	12
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	57	$	2	$	—	$	59
Total Investments	$	1,259	$	32	$	3,346	$	1,296	$	20	$	3,389

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Debt Securities, Available-for-sale

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	93	$	—	$	—	$	83
Equity securities	1,249		18		2,188		1,274		15		2,222
Corporate debt securities	4		3		216		8		—		211
Municipal bonds	1		4		264		4		2		284
U.S. government bonds	4		7		520		8		3		524
Other debt securities	—		—		8		—		—		6
Total NDTF Investments	$	1,258	$	32	$	3,289	$	1,294	$	20	$	3,330
Other Investments
Cash and cash equivalents	$	—	$	—	$	10	$	—	$	—	$	12
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	57	$	2	$	—	$	59
Total Investments	$	1,259	$	32	$	3,346	$	1,296	$	20	$	3,389

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Available-for-sale Securities

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	93	$	—	$	—	$	83
Equity securities	1,249		18		2,188		1,274		15		2,222
Corporate debt securities	4		3		216		8		—		211
Municipal bonds	1		4		264		4		2		284
U.S. government bonds	4		7		520		8		3		524
Other debt securities	—		—		8		—		—		6
Total NDTF Investments	$	1,258	$	32	$	3,289	$	1,294	$	20	$	3,330
Other Investments
Cash and cash equivalents	$	—	$	—	$	10	$	—	$	—	$	12
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	57	$	2	$	—	$	59
Total Investments	$	1,259	$	32	$	3,346	$	1,296	$	20	$	3,389

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	75
Due after one through five years	300
Due after five through 10 years	198
Due after 10 years	482
Total	$	1,055

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	9
Realized losses	8
AFS:
Realized losses	3

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	27
Realized losses	21

Duke Energy Progress [Member]

Schedule of Available-for-sale Securities [Line Items]

Debt Securities, Trading, and Equity Securities, FV-NI

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	59	$	—	$	—	$	50
Equity securities	959		14		1,765		980		12		1,795
Corporate debt securities	3		2		153		6		—		149
Municipal bonds	1		4		263		4		2		283
U.S. government bonds	3		5		326		5		2		310
Other debt securities	—		—		5		—		—		4
Total NDTF Investments	$	966	$	25	$	2,571	$	995	$	16	$	2,591
Other Investments
Cash and cash equivalents	$	—	$	—	$	1	$	—	$	—	$	1
Total Other Investments	$	—	$	—	$	1	$	—	$	—	$	1
Total Investments	$	966	$	25	$	2,572	$	995	$	16	$	2,592

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Debt Securities, Available-for-sale

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	59	$	—	$	—	$	50
Equity securities	959		14		1,765		980		12		1,795
Corporate debt securities	3		2		153		6		—		149
Municipal bonds	1		4		263		4		2		283
U.S. government bonds	3		5		326		5		2		310
Other debt securities	—		—		5		—		—		4
Total NDTF Investments	$	966	$	25	$	2,571	$	995	$	16	$	2,591
Other Investments
Cash and cash equivalents	$	—	$	—	$	1	$	—	$	—	$	1
Total Other Investments	$	—	$	—	$	1	$	—	$	—	$	1
Total Investments	$	966	$	25	$	2,572	$	995	$	16	$	2,592

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Available-for-sale Securities

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	59	$	—	$	—	$	50
Equity securities	959		14		1,765		980		12		1,795
Corporate debt securities	3		2		153		6		—		149
Municipal bonds	1		4		263		4		2		283
U.S. government bonds	3		5		326		5		2		310
Other debt securities	—		—		5		—		—		4
Total NDTF Investments	$	966	$	25	$	2,571	$	995	$	16	$	2,591
Other Investments
Cash and cash equivalents	$	—	$	—	$	1	$	—	$	—	$	1
Total Other Investments	$	—	$	—	$	1	$	—	$	—	$	1
Total Investments	$	966	$	25	$	2,572	$	995	$	16	$	2,592

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	19
Due after one through five years	216
Due after five through 10 years	144
Due after 10 years	368
Total	$	747

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	8
Realized losses	8
AFS:
Realized losses	2

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	24
Realized losses	19

Duke Energy Florida [Member]

Schedule of Available-for-sale Securities [Line Items]

Debt Securities, Trading, and Equity Securities, FV-NI

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	34	$	—	$	—	$	33
Equity securities	290		4		423		294		3		427
Corporate debt securities	1		1		63		2		—		62
Municipal bonds	—		—		1		—		—		1
U.S. government bonds	1		2		194		3		1		214
Other debt securities	—		—		3		—		—		2
Total NDTF Investments(b)	$	292	$	7	$	718	$	299	$	4	$	739
Other Investments
Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	47	$	2	$	—	$	48
Total Investments	$	293	$	7	$	765	$	301	$	4	$	787

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

(b) During the three months endedMarch 31, 2018, Duke Energy Florida continued to receive reimbursements from the NDTF for costs related to ongoing decommissioning activity of the Crystal River Unit 3 nuclear plant.

Debt Securities, Available-for-sale

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	34	$	—	$	—	$	33
Equity securities	290		4		423		294		3		427
Corporate debt securities	1		1		63		2		—		62
Municipal bonds	—		—		1		—		—		1
U.S. government bonds	1		2		194		3		1		214
Other debt securities	—		—		3		—		—		2
Total NDTF Investments(b)	$	292	$	7	$	718	$	299	$	4	$	739
Other Investments
Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	47	$	2	$	—	$	48
Total Investments	$	293	$	7	$	765	$	301	$	4	$	787

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

(b) During the three months endedMarch 31, 2018, Duke Energy Florida continued to receive reimbursements from the NDTF for costs related to ongoing decommissioning activity of the Crystal River Unit 3 nuclear plant.

Available-for-sale Securities

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are classified as FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
NDTF
Cash and cash equivalents	$	—	$	—	$	34	$	—	$	—	$	33
Equity securities	290		4		423		294		3		427
Corporate debt securities	1		1		63		2		—		62
Municipal bonds	—		—		1		—		—		1
U.S. government bonds	1		2		194		3		1		214
Other debt securities	—		—		3		—		—		2
Total NDTF Investments(b)	$	292	$	7	$	718	$	299	$	4	$	739
Other Investments
Cash and cash equivalents	$	—	$	—	$	—	$	—	$	—	$	1
Municipal bonds	1		—		47		2		—		47
Total Other Investments	$	1	$	—	$	47	$	2	$	—	$	48
Total Investments	$	293	$	7	$	765	$	301	$	4	$	787

(a) Where regulatory accounting is applied, realized and unrealized gains and losses are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

(b) During the three months endedMarch 31, 2018, Duke Energy Florida continued to receive reimbursements from the NDTF for costs related to ongoing decommissioning activity of the Crystal River Unit 3 nuclear plant.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	56
Due after one through five years	84
Due after five through 10 years	54
Due after 10 years	114
Total	$	308

Schedule of Realized Gain (Loss)

Realized gains and losses, which were determined on a specific identification basis, from sales of FV-NI and AFS securities for the three months ended March 31, 2018 and from sales of AFS securities for the three months ended March 31, 2017 were as follows.

	Three Months Ended
(in millions)	March 31, 2018
FV-NI:
Realized gains	$	1
AFS:
Realized losses	1

	Three Months Ended
(in millions)	March 31, 2017
Realized gains	$	3
Realized losses	2

Duke Energy Indiana [Member]

Schedule of Available-for-sale Securities [Line Items]

Debt Securities, Trading, and Equity Securities, FV-NI

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
Investments
Equity securities	$	48	$	—	$	96	$	49	$	—	$	97
Corporate debt securities	—		—		5		—		—		3
Municipal bonds	—		1		26		—		1		28
Total Investments	$	48	$	1	$	127	$	49	$	1	$	128

(a) Realized and unrealized gains and losses where regulatory accounting is applied are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Debt Securities, Available-for-sale

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
Investments
Equity securities	$	48	$	—	$	96	$	49	$	—	$	97
Corporate debt securities	—		—		5		—		—		3
Municipal bonds	—		1		26		—		1		28
Total Investments	$	48	$	1	$	127	$	49	$	1	$	128

(a) Realized and unrealized gains and losses where regulatory accounting is applied are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Available-for-sale Securities

The following table presents the estimated fair value of investments in debt and equity securities; equity investments are measured at FV-NI and debt investments are classified as AFS.

	March 31, 2018(a)						December 31, 2017
	Gross		Gross				Gross		Gross
	Unrealized		Unrealized		Estimated		Unrealized		Unrealized		Estimated
	Holding		Holding		Fair		Holding		Holding		Fair
(in millions)	Gains		Losses		Value		Gains		Losses		Value
Investments
Equity securities	$	48	$	—	$	96	$	49	$	—	$	97
Corporate debt securities	—		—		5		—		—		3
Municipal bonds	—		1		26		—		1		28
Total Investments	$	48	$	1	$	127	$	49	$	1	$	128

(a) Realized and unrealized gains and losses where regulatory accounting is applied are deferred as regulatory assets or liabilities, and there is no impact to net income or other comprehensive income until the gain or loss is amortized or collected.

Investments Classified by Contractual Maturity Date

The table below summarizes the maturity date for debt securities.

(in millions)	March 31, 2018
Due in one year or less	$	3
Due after one through five years	15
Due after five through 10 years	6
Due after 10 years	7
Total	$	31

XML

Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2018

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets. Derivative amounts in the tables below for all Duke Energy Registrants exclude cash collateral, which is disclosed in Note 8. See Note 9 for additional information related to investments by major security type for the Duke Energy Registrants.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2			Level 3			Not Categorized
NDTF equity securities	$	4,857		$	4,785		$	—		$	—		$	72
NDTF debt securities	2,169			633			1,536			—			—
Other equity securities	130			130			—			—			—
Other debt securities	258			66			192			—			—
Derivative assets	37			2			27			8			—
Total assets	7,451			5,616			1,755			8			72
Derivative liabilities	(190		)	(1		)	(57		)	(132		)	—
Net assets (liabilities)	$	7,261		$	5,615		$	1,698		$	(124	)	$	72

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2			Level 3			Not Categorized
NDTF equity securities	$	4,914		$	4,840		$	—		$	—		$	74
NDTF debt securities	2,174			635			1,539			—			—
Other equity securities	123			123			—			—			—
Other debt securities	241			57			184			—			—
Derivative assets	51			3			20			28			—
Total assets	7,503			5,658			1,743			28			74
Derivative liabilities	(230		)	(2		)	(86		)	(142		)	—
Net assets (liabilities)	$	7,273		$	5,656		$	1,657		$	(114	)	$	74

Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs

The following table provides reconciliations of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements. Amounts included in earnings for derivatives are primarily included in Cost of natural gas on the Duke Energy Registrants' Condensed Consolidated Statements of Operations and Comprehensive Income. Amounts included in changes of net assets on the Duke Energy Registrants' Condensed Consolidated Balance Sheets are included in regulatory assets or liabilities. All derivative assets and liabilities are presented on a net basis.

	Three Months Ended March 31, 2018								Three Months Ended March 31, 2017
(in millions)	Investments		Derivatives (net)			Total			Investments		Derivatives (net)			Total
Balance at beginning of period	$	—	$	(114	)	$	(114	)	$	5	$	(166	)	$	(161	)
Purchases, sales, issuances and settlements:
Settlements	—		(14		)	(14		)	—		(9		)	(9		)
Total gains included on the Condensed Consolidated Balance Sheet	—		4			4			—		40			40
Balance at end of period	$	—	$	(124	)	$	(124	)	$	5	$	(135	)	$	(130	)

Quantitative Information Table - Level 3

The following tables include quantitative information about the Duke Energy Registrants' derivatives classified as Level 3.

	March 31, 2018
	Fair Value
Investment Type	(in millions)			Valuation Technique	Unobservable Input	Range
Duke Energy Ohio
Financial Transmission Rights (FTRs)	$	1		RTO auction pricing	FTR price – per megawatt-hour (MWh)	$	—		-	$	2.88
Duke Energy Indiana
FTRs	7			RTO auction pricing	FTR price – per MWh	(5.09		)	-	7.58
Piedmont
Natural gas contracts	(132		)	Discounted cash flow	Forward natural gas curves – price per million British thermal unit (MMBtu)	2.15			-	3.65
Duke Energy
Total Level 3 derivatives	$	(124	)

	December 31, 2017
	Fair Value
Investment Type	(in millions)			Valuation Technique	Unobservable Input	Range
Duke Energy Ohio
FTRs	$	1		RTO auction pricing	FTR price – per MWh	$	0.07		-	$	1.41
Duke Energy Indiana
FTRs	27			RTO auction pricing	FTR price – per MWh	(0.77		)	-	7.44
Piedmont
Natural gas contracts	(142		)	Discounted cash flow	Forward natural gas curves – price per MMBtu	2.10			-	2.88
Duke Energy
Total Level 3 derivatives	$	(114	)

Schedule Of Long Term Debt Fair Value

The fair value and book value of long-term debt, including current maturities, is summarized in the following table. Estimates determined are not necessarily indicative of amounts that could have been settled in current markets. Fair value of long-term debt uses Level 2 measurements.

	March 31, 2018				December 31, 2017
(in millions)	Book Value		Fair Value		Book Value		Fair Value
Duke Energy	$	52,981	$	54,383	$	52,279	$	55,331
Duke Energy Carolinas	10,694		11,556		10,103		11,372
Progress Energy	17,757		19,270		17,837		20,000
Duke Energy Progress	7,357		7,687		7,357		7,992
Duke Energy Florida	7,015		7,632		7,095		7,953
Duke Energy Ohio	2,067		2,217		2,067		2,249
Duke Energy Indiana	3,782		4,322		3,783		4,464
Piedmont	2,037		2,209		2,037		2,209

Duke Energy Carolinas [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2			Not Categorized
NDTF equity securities	$	2,669		$	2,597		$	—		$	72
NDTF debt securities	1,068			209			859			—
Derivative assets	2			—			2			—
Total assets	3,739			2,806			861			72
Derivative liabilities	(11		)	(1		)	(10		)	—
Net assets	$	3,728		$	2,805		$	851		$	72

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2			Not Categorized
NDTF equity securities	$	2,692		$	2,618		$	—		$	74
NDTF debt securities	1,066			204			862			—
Derivative assets	2			—			2			—
Total assets	3,760			2,822			864			74
Derivative liabilities	(35		)	(1		)	(34		)	—
Net assets	$	3,725		$	2,821		$	830		$	74

Progress Energy [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	2,188		$	2,188		$	—
NDTF debt securities	1,101			424			677
Other debt securities	57			10			47
Derivative assets	3			—			3
Total assets	3,349			2,622			727
Derivative liabilities	(37		)	(1		)	(36		)
Net assets	$	3,312		$	2,621		$	691

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	2,222		$	2,222		$	—
NDTF debt securities	1,108			431			677
Other debt securities	59			12			47
Derivative assets	3			1			2
Total assets	3,392			2,666			726
Derivative liabilities	(36		)	(1		)	(35		)
Net assets	$	3,356		$	2,665		$	691

Duke Energy Progress [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	1,765		$	1,765		$	—
NDTF debt securities	806			254			552
Other debt securities	1			1			—
Derivative assets	2			—			2
Total assets	2,574			2,020			554
Derivative liabilities	(21		)	(1		)	(20		)
Net assets	$	2,553		$	2,019		$	534

	December 31, 2017
(in millions)	Total Fair Value			Level 1			Level 2
NDTF equity securities	$	1,795		$	1,795		$	—
NDTF debt securities	796			243			553
Other debt securities	1			1			—
Derivative assets	2			1			1
Total assets	2,594			2,040			554
Derivative liabilities	(18		)	(1		)	(17		)
Net assets	$	2,576		$	2,039		$	537

Duke Energy Florida [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1		Level 2
NDTF equity securities	$	423		$	423	$	—
NDTF debt securities	295			170		125
Other debt securities	47			—		47
Derivative assets	1			—		1
Total assets	766			593		173
Derivative liabilities	(7		)	—		(7		)
Net assets	$	759		$	593	$	166

	December 31, 2017
(in millions)	Total Fair Value			Level 1		Level 2
NDTF equity securities	$	427		$	427	$	—
NDTF debt securities	312			188		124
Other debt securities	48			1		47
Derivative assets	1			—		1
Total assets	788			616		172
Derivative liabilities	(12		)	—		(12		)
Net assets	$	776		$	616	$	160

Duke Energy Ohio [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following table provides recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018								December 31, 2017
(in millions)	Total Fair Value			Level 2			Level 3		Total Fair Value			Level 2			Level 3
Derivative assets	$	1		$	—		$	1	$	1		$	—		$	1
Derivative liabilities	(4		)	(4		)	—		(5		)	(5		)	—
Net (liabilities) assets	$	(3	)	$	(4	)	$	1	$	(4	)	$	(5	)	$	1

Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018		2017
Balance at beginning of period	$	1	$	5
Purchases, sales, issuances and settlements:
Settlements	—		(1		)
Total losses included on the Condensed Consolidated Balance Sheet	—		(3		)
Balance at end of period	$	1	$	1

Duke Energy Indiana [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value		Level 1		Level 2		Level 3
Other equity securities	$	96	$	96	$	—	$	—
Other debt securities	31		—		31		—
Derivative assets	7		—		—		7
Total assets	134		96		31		7
Derivative liabilities	—		—		—		—
Net assets	$	134	$	96	$	31	$	7

	December 31, 2017
(in millions)	Total Fair Value		Level 1		Level 2		Level 3
Other equity securities	$	97	$	97	$	—	$	—
Other debt securities	31		—		31		—
Derivative assets	27		—		—		27
Total assets	155		97		31		27
Derivative liabilities	—		—		—		—
Net assets	$	155	$	97	$	31	$	27

Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018			2017
Balance at beginning of period	$	27		$	16
Purchases, sales, issuances and settlements:
Settlements	(14		)	(7		)
Total (losses) gains included on the Condensed Consolidated Balance Sheet	(6		)	—
Balance at end of period	$	7		$	9

Piedmont Natural Gas [Member]

Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]

Fair Value Measurement Amounts For Assets And Liabilities

The following tables provide recorded balances for assets and liabilities measured at fair value on a recurring basis on the Condensed Consolidated Balance Sheets.

	March 31, 2018
(in millions)	Total Fair Value			Level 1		Level 3
Derivative assets	$	1		$	1	$	—
Derivative liabilities	(132		)	—		(132		)
Net (liabilities) assets	$	(131	)	$	1	$	(132	)

	December 31, 2017
(in millions)	Total Fair Value			Level 1		Level 3
Other debt securities	$	1		$	1	$	—
Derivative assets	2			2		—
Total assets	3			3		—
Derivative liabilities	(142		)	—		(142		)
Net (liabilities) assets	$	(139	)	$	3	$	(142	)

Reconciliation Of Assets And Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs

The following table provides a reconciliation of beginning and ending balances of assets and liabilities measured at fair value using Level 3 measurements.

	Derivatives (net)
	Three Months Ended March 31,
(in millions)	2018			2017
Balance at beginning of period	$	(142	)	$	(187	)
Total gains and settlements	10			42
Balance at end of period	$	(132	)	$	(145	)

XML

Variable Interest Entities (Tables)

3 Months Ended

Mar. 31, 2018

Variable Interest Entity, Primary Beneficiary [Member]

Variable Interest Entities [Line Items]

Schedule Of Variable Interest Entities

The following table summarizes the amounts and expiration dates of the credit facilities and associated restricted receivables described above.

	Duke Energy
			Duke Energy		Duke Energy		Duke Energy
			Carolinas		Progress		Florida
(in millions)	CRC		DERF		DEPR		DEFR
Expiration date	December 2020		December 2020		February 2021		April 2019		(a)
Credit facility amount	$	325	$	450	$	300	$	225
Amounts borrowed at March 31, 2018	325		450		300		225
Amounts borrowed at December 31, 2017	325		450		300		225
Restricted Receivables at March 31, 2018	504		634		497		313
Restricted Receivables at December 31, 2017	545		640		459		317

(a)    In April 2018, the credit facility was extended through April 2021.

Variable Interest Entity, Not Primary Beneficiary [Member]

Variable Interest Entities [Line Items]

Schedule Of Variable Interest Entities

The following tables summarize the impact of non-consolidated VIEs on the Condensed Consolidated Balance Sheets.

	March 31, 2018
	Duke Energy										Duke		Duke
	Pipeline			Commercial		Other					Energy		Energy
(in millions)	Investments			Renewables		VIEs		Total			Ohio		Indiana
Receivables from affiliated companies	$	—		$	—	$	—	$	—		$	65	$	86
Investments in equity method unconsolidated affiliates	723			183		45		951			—		—
Other noncurrent assets	17			—		—		17			—		—
Total assets	$	740		$	183	$	45	$	968		$	65	$	86
Taxes accrued	(29		)	—		—		(29		)	—		—
Other current liabilities	—			—		3		3			—		—
Deferred income taxes	32			—		—		32			—		—
Other noncurrent liabilities	8			—		12		20			—		—
Total liabilities	$	11		$	—	$	15	$	26		$	—	$	—
Net assets	$	729		$	183	$	30	$	942		$	65	$	86

	December 31, 2017
	Duke Energy										Duke		Duke
	Pipeline			Commercial		Other					Energy		Energy
(in millions)	Investments			Renewables		VIEs		Total			Ohio		Indiana
Receivables from affiliated companies	$	—		$	—	$	—	$	—		$	87	$	106
Investments in equity method unconsolidated affiliates	697			180		42		919			—		—
Other noncurrent assets	17			—		—		17			—		—
Total assets	$	714		$	180	$	42	$	936		$	87	$	106
Taxes accrued	(29		)	—		—		(29		)	—		—
Other current liabilities	—			—		4		4			—		—
Deferred income taxes	42			—		—		42			—		—
Other noncurrent liabilities	—			—		12		12			—		—
Total liabilities	$	13		$	—	$	16	$	29		$	—	$	—
Net assets	$	701		$	180	$	26	$	907		$	87	$	106

DEFPF [Member] | Variable Interest Entity, Primary Beneficiary [Member]

Variable Interest Entities [Line Items]

Schedule Of Variable Interest Entities

The following table summarizes the impact of DEFPF on Duke Energy Florida's Condensed Consolidated Balance Sheets.

(in millions)	March 31, 2018		December 31, 2017
Receivables of VIEs	$	4	$	4
Regulatory Assets: Current	51		51
Current Assets: Other	13		40
Other Noncurrent Assets: Regulatory assets	1,082		1,091
Current Liabilities: Other	3		10
Current maturities of long-term debt	53		53
Long-Term Debt	1,136		1,164

Commercial Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]

Variable Interest Entities [Line Items]

Schedule Of Variable Interest Entities

The table below presents material balances reported on Duke Energy's Condensed Consolidated Balance Sheets related to renewables VIEs.

(in millions)	March 31, 2018			December 31, 2017
Current Assets: Other	$	217		$	174
Property, plant and equipment, cost	4,017			3,923
Other Noncurrent Assets: Other	227			50
Accumulated depreciation and amortization	(626		)	(591		)
Current maturities of long-term debt	171			170
Long-Term Debt	1,700			1,700
Other Noncurrent Liabilities: Deferred income taxes	—			(148		)
Other Noncurrent Liabilities: Other	236			241

Pipeline Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]

Variable Interest Entities [Line Items]

Schedule Of Variable Interest Entities

The table below presents Duke Energy's ownership interest and investment balances in these joint ventures.

			VIE Investment Amount (in millions)
	Ownership		March 31,		December 31,
Entity Name	Interest		2018		2017
ACP	47	%	$	474	$	397
Sabal Trail	7.5	%	223		219
Constitution(a)	24	%	26		81
Total			$	723	$	697

(a) During the three months ended March 31, 2018, Duke Energy recorded an OTTI of $55 million related to Constitution within Equity in (losses) earnings of unconsolidated affiliates on Duke Energy's Condensed Consolidated Statements of Income. See Note 3 for additional information.

Cinergy Receivables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]

Variable Interest Entities [Line Items]

Schedule Of Variable Interest Entities

Key assumptions used in estimating fair value are detailed in the following table.

	Duke Energy Ohio				Duke Energy Indiana
	2018		2017		2018		2017
Anticipated credit loss ratio	0.5	%	0.5	%	0.3	%	0.3	%
Discount rate	2.6	%	2.1	%	2.6	%	2.1	%
Receivable turnover rate	13.6	%	13.5	%	10.8	%	10.7	%

The following table shows the gross and net receivables sold.

	Duke Energy Ohio				Duke Energy Indiana
(in millions)	March 31, 2018		December 31, 2017		March 31, 2018		December 31, 2017
Receivables sold	$	249	$	273	$	297	$	312
Less: Retained interests	65		87		86		106
Net receivables sold	$	184	$	186	$	211	$	206

The following table shows sales and cash flows related to receivables sold.

	Duke Energy Ohio				Duke Energy Indiana
	Three Months Ended				Three Months Ended
	March 31,				March 31,
(in millions)	2018		2017		2018		2017
Sales
Receivables sold	$	567	$	533	$	694	$	664
Loss recognized on sale	3		2		3		3
Cash flows
Cash proceeds from receivables sold	$	585	$	559	$	711	$	693
Return received on retained interests	2		1		2		2

XML

Revenue (Tables)

3 Months Ended

Mar. 31, 2018

Revenue from Contract with Customer [Abstract]

Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction

Estimated remaining performance obligations are as follows:

	Remaining Performance Obligations
(in millions)	2018		2019		2020		2021		2022		Thereafter		Total
Piedmont	$	55	$	72	$	70	$	65	$	64	$	482	$	808

Supplemental requirements contracts that include contracted blocks of energy and capacity at contractually fixed prices have the following estimated remaining performance obligations:

	Remaining Performance Obligations
(in millions)	2018		2019		2020		2021		2022		Thereafter		Total
Progress Energy	$	69	$	112	$	121	$	80	$	82	$	81	$	545
Duke Energy Progress	7		9		9		9		9		18		61
Duke Energy Florida	62		103		112		71		73		63		484
Duke Energy Indiana	6		9		10		5		—		—		30

Disaggregation of Revenue

Disaggregated revenues are presented as follows:

	Three Months Ended March 31, 2018
			Duke				Duke		Duke		Duke		Duke
(in millions)	Duke		Energy		Progress		Energy		Energy		Energy		Energy
By market or type of customer	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Electric Utilities and Infrastructure
Residential	$	2,350	$	781	$	1,112	$	516	$	595	$	180	$	278	$	—
General	1,375		472		631		299		333		96		178		—
Industrial	664		255		208		145		62		30		173		—
Wholesale	633		119		446		397		50		—		68		—
Other revenues	139		67		129		85		43		14		17		—
Total Electric Utilities and Infrastructure revenue from contracts with customers	$	5,161	$	1,694	$	2,526	$	1,442	$	1,083	$	320	$	714	$	—
Gas Utilities and Infrastructure
Residential	$	413	$	—	$	—	$	—	$	—	$	111	$	—	$	302
Commercial	201		—		—		—		—		49		—		152
Industrial	48		—		—		—		—		7		—		41
Power Generation	—		—		—		—		—		—		—		13
Other revenues	55		—		—		—		—		6		—		49
Total Gas Utilities and Infrastructure revenue from contracts with customers	$	717	$	—	$	—	$	—	$	—	$	173	$	—	$	557
Commercial Renewables
Revenue from contracts with customers	$	33	$	—	$	—	$	—	$	—	$	—	$	—	$	—
Other
Revenue from contracts with customers	$	17	$	—	$	—	$	—	$	—	$	14	$	—	$	—
Total revenue from contracts with customers	$	5,928	$	1,694	$	2,526	$	1,442	$	1,083	$	507	$	714	$	557
Other revenue sources (a)	$	207	$	69	$	50	$	18	$	32	$	17	$	17	$	(4	)
Total revenues	$	6,135	$	1,763	$	2,576	$	1,460	$	1,115	$	524	$	731	$	553

(a) Other revenue sources include revenues from leases, derivatives and alternative revenue programs that are not considered revenues from contracts with customers. Piedmont has regulatory mechanisms that periodically provide rate adjustments to refund any over-collection or to recover any under-collection of margin.

Schedule Of Unbilled Revenues With Restricted Receivables

These receivables for unbilled revenues are shown in the table below.

(in millions)	March 31, 2018		December 31, 2017
Duke Energy Ohio	$	67	$	104
Duke Energy Indiana	108		132

Unbilled revenues are included within Receivables and Receivables of variable interest entities (VIEs) on the Condensed Consolidated Balance Sheets as shown in the following table.

(in millions)	March 31, 2018		December 31, 2017
Duke Energy	$	823	$	944
Duke Energy Carolinas	310		342
Progress Energy	237		228
Duke Energy Progress	167		143
Duke Energy Florida	70		85
Duke Energy Ohio	2		4
Duke Energy Indiana	24		21
Piedmont	45		86

XML

Common Stock (Tables)

3 Months Ended

Mar. 31, 2018

Earnings Per Share [Abstract]

Schedule Of Earnings Per Share

The following table presents Duke Energy’s basic and diluted EPS calculations and reconciles the weighted average number of common shares outstanding to the diluted weighted average number of common shares outstanding.

	Three Months Ended March 31,
(in millions, except per-share amounts)	2018		2017
Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities	$	619	$	715
Weighted average shares outstanding – basic	701		700
Weighted average shares outstanding – diluted	701		700
Earnings per share from continuing operations attributable to Duke Energy common stockholders
Basic	$	0.88	$	1.02
Diluted	$	0.88	$	1.02
Potentially dilutive items excluded from the calculation(a)	2		2
Dividends declared per common share	$	0.89	$	0.855

(a) Performance stock awards were not included in the dilutive securities calculation because the performance measures related to the awards had not been met.

XML

Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2018

Disclosure of Compensation Related Costs, Share-based Payments [Abstract]

Schedule Of Stock-Based Compensation Expense

Pretax stock-based compensation costs, the tax benefit associated with stock-based compensation expense and stock-based compensation costs capitalized are included in the following table.

	Three Months Ended
	March 31,
(in millions)	2018		2017
Restricted stock unit awards	$	10	$	8
Performance awards	7		7
Pretax stock-based compensation cost	$	17	$	15
Tax benefit associated with stock-based compensation expense	$	4	$	5
Stock-based compensation costs capitalized	1		1

XML

Employee Benefit Plans (Tables)

3 Months Ended

Mar. 31, 2018

Defined Benefit Plan Disclosure [Line Items]

Defined Contribution Plan Disclosures

The following table includes employer contributions made by Duke Energy and expensed by the Subsidiary Registrants.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Three Months Ended March 31,
2018	$	70	$	23	$	19	$	13	$	6	$	1	$	3	$	4
2017	65		22		18		13		5		1		3		2

Qualified Pension Plan [Member]

Defined Benefit Plan Disclosure [Line Items]

Schedule of Defined Benefit Plans Disclosures

The following table includes information related to the Duke Energy Registrants' contributions to its qualified defined benefit pension plans.

			Duke				Duke		Duke		Duke		Duke
	Duke		Energy		Progress		Energy		Energy		Energy		Energy
(in millions)	Energy		Carolinas		Energy		Progress		Florida		Ohio		Indiana		Piedmont
Total anticipated 2018 contributions	$	148	$	46	$	45	$	25	$	20	$	—	$	8	$	7
Contributions made during the three months ended March 31, 2018	141		46		45		25		20		—		8		—
Remaining estimated 2018 contributions	$	7	$	—	$	—	$	—	$	—	$	—	$	—	$	7

Components of Net Periodic Pension Costs

The following tables include the components of net periodic pension costs for qualified pension plans.

	Three Months Ended March 31, 2018
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	45		$	15		$	13		$	7		$	5		$	1		$	2		$	2
Interest cost on projected benefit obligation	75			18			24			11			13			5			6			3
Expected return on plan assets	(140		)	(37		)	(45		)	(21		)	(23		)	(7		)	(10		)	(6		)
Amortization of actuarial loss	33			7			11			5			6			1			2			3
Amortization of prior service credit	(8		)	(2		)	(1		)	—			—			—			—			(3		)
Net periodic pension costs	$	5		$	1		$	2		$	2		$	1		$	—		$	—		$	(1	)

	Three Months Ended March 31, 2017
				Duke						Duke			Duke			Duke			Duke
	Duke			Energy			Progress			Energy			Energy			Energy			Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio			Indiana			Piedmont
Service cost	$	40		$	12		$	12		$	6		$	5		$	1		$	2		$	3
Interest cost on projected benefit obligation	82			20			25			12			13			5			7			3
Expected return on plan assets	(136		)	(35		)	(43		)	(21		)	(21		)	(7		)	(11		)	(6		)
Amortization of actuarial loss	36			8			14			6			7			1			3			3
Amortization of prior service credit	(6		)	(2		)	(1		)	—			—			—			—			(1		)
Other	2			—			1			—			—			—			—			—
Net periodic pension costs	$	18		$	3		$	8		$	3		$	4		$	—		$	1		$	2

Other Post-Retirement Benefit Plans [Member]

Defined Benefit Plan Disclosure [Line Items]

Components of Net Periodic Pension Costs

The following tables include the components of net periodic other post-retirement benefit costs.

	Three Months Ended March 31, 2018
				Duke						Duke		Duke			Duke		Duke
	Duke			Energy			Progress			Energy		Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress		Florida			Ohio		Indiana		Piedmont
Service cost	$	1		$	—		$	—		$	—	$	—		$	—	$	—	$	—
Interest cost on accumulated post-retirement benefit obligation	7			2			4			1		1			—		1		—
Expected return on plan assets	(2		)	(2		)	—			—		—			—		—		—
Amortization of actuarial loss	1			—			—			—		—			—		1		—
Amortization of prior service credit	(5		)	(1		)	(2		)	—		(1		)	—		—		—
Net periodic other post-retirement benefit costs	$	2		$	(1	)	$	2		$	1	$	—		$	—	$	2	$	—

	Three Months Ended March 31, 2017
				Duke						Duke			Duke			Duke		Duke
	Duke			Energy			Progress			Energy			Energy			Energy		Energy
(in millions)	Energy			Carolinas			Energy			Progress			Florida			Ohio		Indiana		Piedmont
Service cost	$	1		$	—		$	—		$	—		$	—		$	—	$	—	$	—
Interest cost on accumulated post-retirement benefit obligation	9			2			4			2			2			—		—		—
Expected return on plan assets	(3		)	(2		)	—			—			—			—		—		—
Amortization of actuarial loss (gain)	2			(1		)	5			3			2			—		—		—
Amortization of prior service credit	(29		)	(2		)	(21		)	(14		)	(8		)	—		—		—
Net periodic other post-retirement benefit costs	$	(20	)	$	(3	)	$	(12	)	$	(9	)	$	(4	)	$	—	$	—	$	—

XML

Income Taxes (Tables)

3 Months Ended

Mar. 31, 2018

Income Tax Disclosure [Abstract]

Summary of Effective Tax Rates

The effective tax rates from continuing operations for each of the Duke Energy Registrants are included in the following table.

	Three Months Ended
	March 31,
	2018		2017
Duke Energy	22.5	%	32.4	%
Duke Energy Carolinas	22.0	%	35.4	%
Progress Energy	13.2	%	34.1	%
Duke Energy Progress	14.1	%	34.1	%
Duke Energy Florida	16.3	%	36.6	%
Duke Energy Ohio	32.4	%	35.4	%
Duke Energy Indiana	25.9	%	39.3	%
Piedmont	24.1	%	37.9	%

XML

Organization and Basis of Presentation (Schedule of Cash and Cash Equivalents) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017	Mar. 31, 2017	Dec. 31, 2016
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents, at Carrying Value	$ 421	$ 358
Restricted Cash and Cash Equivalents, Current	149	138
Restricted Cash and Cash Equivalents, Noncurrent	9	9
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	579	505	$ 1,022	$ 541
Progress Energy [Member]
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents, at Carrying Value	20	40
Restricted Cash and Cash Equivalents, Current	13	40
Restricted Cash and Cash Equivalents, Noncurrent	6	7
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	39	87	58	110
Duke Energy Florida [Member]
Cash and Cash Equivalents [Line Items]
Cash and Cash Equivalents, at Carrying Value	6	13
Restricted Cash and Cash Equivalents, Current	13	40
Restricted Cash and Cash Equivalents, Noncurrent	0	0
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	$ 19	$ 53	$ 21	$ 69

XML

Organization and Basis of Presentation (Schedule of Inventory) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Public Utilities, Inventory [Line Items]
Inventory	$ 3,149	$ 3,250
Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	2,293	2,293
Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	551	603
Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	305	354
Duke Energy Carolinas [Member]
Public Utilities, Inventory [Line Items]
Inventory	980	971
Duke Energy Carolinas [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	763	744
Duke Energy Carolinas [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	176	192
Duke Energy Carolinas [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	41	35
Progress Energy [Member]
Public Utilities, Inventory [Line Items]
Inventory	1,537	1,592
Progress Energy [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	1,095	1,118
Progress Energy [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	221	255
Progress Energy [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	221	219
Duke Energy Progress [Member]
Public Utilities, Inventory [Line Items]
Inventory	1,002	1,017
Duke Energy Progress [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	767	774
Duke Energy Progress [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	125	139
Duke Energy Progress [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	110	104
Duke Energy Florida [Member]
Public Utilities, Inventory [Line Items]
Inventory	535	574
Duke Energy Florida [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	329	343
Duke Energy Florida [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	96	116
Duke Energy Florida [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	110	115
Duke Energy Ohio [Member]
Public Utilities, Inventory [Line Items]
Inventory	108	133
Duke Energy Ohio [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	82	82
Duke Energy Ohio [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	13	17
Duke Energy Ohio [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	13	34
Duke Energy Indiana [Member]
Public Utilities, Inventory [Line Items]
Inventory	453	450
Duke Energy Indiana [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	310	309
Duke Energy Indiana [Member] | Coal [Member]
Public Utilities, Inventory [Line Items]
Inventory	141	139
Duke Energy Indiana [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	2	2
Piedmont Natural Gas [Member]
Public Utilities, Inventory [Line Items]
Inventory	29	66
Piedmont Natural Gas [Member] | Materials and supplies [Member]
Public Utilities, Inventory [Line Items]
Inventory	1	2
Piedmont Natural Gas [Member] | Natural gas, oil and other fuel [Member]
Public Utilities, Inventory [Line Items]
Inventory	$ 28	$ 64

XML

Organization and Basis of Presentation (Schedule of Excise Taxes) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 99	$ 91
Duke Energy Carolinas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	8	9
Progress Energy [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	54	46
Duke Energy Progress [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	5	5
Duke Energy Florida [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	49	41
Duke Energy Ohio [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	30	28
Duke Energy Indiana [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	6	7
Piedmont Natural Gas [Member]
Organization And Basis Of Presentation [Line Items]
Excise taxes collected	$ 1	$ 1

XML

Organization and Basis of Presentation (New Accounting Standards) (Details) - Accounting Standards Update 2017-07 (1) [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Expense [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 156	$ 131	$ 96
Nonoperating Income (Expense) [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Effect of Adoption, Quantification	$ 156	$ 131	$ 96

XML

Business Segments (Narrative) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) segment	Mar. 31, 2017 USD ($)
Segment Reporting Information [Line Items]
Loss on Sales of Other Assets and Other, net	$ 100	$ (11)
Operation, maintenance and other	1,464	1,468
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Loss on Sales of Other Assets and Other, net	106
Operation, maintenance and other	$ 131	$ 131
Number of Reportable Segments | segment	2
Beckjord [Member]
Segment Reporting Information [Line Items]
Loss on Sales of Other Assets and Other, net	$ 106
Operation, maintenance and other	$ 1
National Methanol Company [Member]
Segment Reporting Information [Line Items]
Equity Method Investment, Ownership Percentage	17.50%

XML

Business Segments (Business Segment Data) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Segment Reporting Information [Line Items]
Operating revenues	$ 6,135	$ 5,729
Segment income (loss)	620	716
Net Income (Loss) Attributable to Noncontrolling Interest	2	1
Net income	622	717
Segment assets	138,541		$ 137,914
Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,315	4,939
Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	702	648
Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	101	128
Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	6,118	5,715
Other Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	17	14
Operating Segments [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	886	793
Segment assets	135,682
Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	5,323	4,947
Segment income (loss)	750	635
Segment assets	120,021
Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	727	670
Segment income (loss)	116	133
Segment assets	11,396
Operating Segments [Member] | Commercial Renewables [Member]
Segment Reporting Information [Line Items]
Operating revenues	101	128
Segment income (loss)	20	25
Segment assets	4,265
Operating Segments [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	6,151	5,745
Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	(51)	(49)
Segment assets	177
Intersegment Eliminations [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	8	8
Intersegment Eliminations [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	25	22
Intersegment Eliminations [Member] | Total Reportable Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	33	30
Intersegment Eliminations [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	18	19
Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Segment income (loss)	(266)	(77)
Segment assets	2,682
Corporate, Non-Segment [Member] | Other Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	35	33
Duke Energy Ohio [Member]
Segment Reporting Information [Line Items]
Operating revenues	524	518
Segment income (loss)	(25)	42
Segment assets	7,896		$ 7,875
Duke Energy Ohio [Member] | Operating Segments [Member]
Segment Reporting Information [Line Items]
Operating revenues	510	507
Segment income (loss)	67	50
Segment assets	7,874
Duke Energy Ohio [Member] | Operating Segments [Member] | Electric Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	336	337
Segment income (loss)	33	24
Segment assets	5,165
Duke Energy Ohio [Member] | Operating Segments [Member] | Gas Utilities and Infrastructure [Member]
Segment Reporting Information [Line Items]
Operating revenues	174	170
Segment income (loss)	34	26
Segment assets	2,709
Duke Energy Ohio [Member] | Intersegment Eliminations [Member]
Segment Reporting Information [Line Items]
Segment assets	(3)
Duke Energy Ohio [Member] | Corporate, Non-Segment [Member]
Segment Reporting Information [Line Items]
Operating revenues	14	11
Segment income (loss)	(92)	$ (8)
Segment assets	$ 25

XML

Regulatory Matters (Narrative) (Details) Customers in Millions, $ in Millions			1 Months Ended			3 Months Ended		12 Months Ended
	Apr. 13, 2018 USD ($)	Apr. 02, 2018 USD ($)	Feb. 28, 2018 USD ($)	Jun. 30, 2017 USD ($)	Dec. 31, 2015 USD ($)	Mar. 31, 2018 USD ($) Customers MW	Mar. 31, 2017 USD ($)	Dec. 31, 2017 USD ($)
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						$ 1,464.0	$ 1,468.0
Public Utilities, Property, Plant and Equipment, Net						87,373.0		$ 86,391.0
Loss Before Income Taxes						(803.0)	(1,061.0)
Electric Domestic Regulated Revenue						5,284.0	4,913.0
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net						$ 391.0
Capacity (in MW) | MW						1,738
Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						47.00%
Long-term Purchase Commitment, Period						20 years
Sabal Trail Transmission Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						7.50%
Estimated capital cost						$ 3,200.0
Long-term Purchase Commitment, Period						25 years
Constitution Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						24.00%
Estimated Contributions						$ 229.0
Equity Method Investment, Other than Temporary Impairment						$ 55.0
Dominion Resources [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						48.00%
Southern Company Gas [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						5.00%
Spectra Energy Partners [Member] | Sabal Trail Transmission Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						50.00%
NextEra Energy [Member] | Sabal Trail Transmission Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						42.50%
Williams Partners L.P. [Member] | Constitution Pipeline [Member]
Public Utilities, General Disclosures [Line Items]
Joint owner ownership percentage						41.00%
Minimum [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost						$ 6,000.0
Original estimated capital cost						5,000.0
Maximum [Member] | Atlantic Coast Pipeline (ACP) [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost						6,500.0
Original estimated capital cost						5,500.0
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						451.0	495.0
Public Utilities, Property, Plant and Equipment, Net						28,158.0		27,876.0
Loss Before Income Taxes						(414.0)	(418.0)
Duke Energy Carolinas [Member] | William States Lee Combined Cycle Facility [Member] | NCEMC [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC						$ 650.0
Joint owner ownership percentage						13.00%
Duke Energy Carolinas [Member] | William State Lee III Nuclear Station [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net						$ 558.0
Duke Energy Carolinas [Member] | 2017 North Carolina Rate Case [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						$ 647.0
Requested Rate Increase, Percentage						13.60%
Requested Return on Equity, Percentage						9.90%
Public Utilities, Requested Equity Capital Structure, Percentage						52.00%
Public Utilities, Requested Debt Capital Structure, Percentage						48.00%
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses			$ 4.0
Requested Rate Increase (Decrease), Amended, Amount						$ 472.0
Loss Before Income Taxes						14.0
Duke Energy Carolinas [Member] | FERC Formula Rate Matter [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Customer Refundable Fees, Refund Payments						25.0
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						623.0	560.0
Public Utilities, Property, Plant and Equipment, Net						32,254.0		31,887.0
Loss Before Income Taxes						(273.0)	(305.0)
Duke Energy Progress [Member]
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						381.0	362.0
Public Utilities, Property, Plant and Equipment, Net						19,253.0		19,101.0
Loss Before Income Taxes						(206.0)	(223.0)
Duke Energy Progress [Member] | Asheville Plant [Member] | Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net						$ 365.0		385.0
Capacity (in MW) | MW						376
Duke Energy Progress [Member] | 2017 North Carolina Rate Case [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						$ 477.0
Requested Rate Increase, Percentage						14.90%
Requested Return on Equity, Percentage						9.90%
Public Utilities, Requested Equity Capital Structure, Percentage						52.00%
Public Utilities, Requested Debt Capital Structure, Percentage						48.00%
Requested Rate Increase (Decrease), Amended, Amount						$ 420.0
Requested Rate Increase (Decrease), Amended, Percentage						13.00%
Estimated Storm Costs - Capital and Operation Maintenance						$ 116.0
Utilities Operating Expense, Impairments								25.0
Penalty assessed						30.0
Estimated future coal ash costs						129.0
Loss Before Income Taxes						$ 68.0
Duke Energy Progress [Member] | 2017 North Carolina Rate Case [Member] | NCUC [Member] | Asset retirement obligations - coal ash [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Asset, Amortization Period						5 years
Excluded deferred coal ash costs						$ 9.5
Regulatory Assets						234.0
Duke Energy Progress [Member] | 2017 North Carolina Rate Case [Member] | NCUC [Member] | Storm Costs [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						$ 80.0
Regulatory Asset, Amortization Period						5 years
Approved Rate Increase (Decrease), Amount						$ 51.0
Duke Energy Progress [Member] | 2016 South Carolina Rate Case Settlement [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount						$ 56.0
Asset Retirement Obligation, Accretion Expense								18.5
Approved return on equity percentage						10.10%
Duke Energy Progress [Member] | 2016 South Carolina Rate Case Settlement Year 1 Increase [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount						$ 38.0
Duke Energy Progress [Member] | 2016 South Carolina Rate Case Settlement Year 2 Increase [Member] | PSCSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount						$ 18.5
Duke Energy Progress [Member] | Western Carolinas Modernization Plan [Member] | NCUC [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Asset, Amortization Period						10 years
Estimated capital cost						$ 893.0
Duke Energy Progress [Member] | Shearon Harris Nuclear Expansion [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Asset, Amortization Period						8 years
Wholesale Debt Return Amortization Period						15 years
Regulatory Assets								47.0
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						$ 237.0	195.0
Public Utilities, Property, Plant and Equipment, Net						12,998.0		12,783.0
Loss Before Income Taxes						(123.0)	(142.0)
Duke Energy Florida [Member] | Storm Costs [Member]
Public Utilities, General Disclosures [Line Items]
Regulatory Assets						338.0
Duke Energy Florida [Member] | Citrus County Station [Member]
Public Utilities, General Disclosures [Line Items]
Estimated capital cost of new utility plant, including AFUDC						1,500.0
Duke Energy Florida [Member] | Storm Restoration Cost Recovery [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Storm Costs - Capital and Operation Maintenance						$ 513.0
Customers Experiencing Outages | Customers						1.3
Duke Energy Florida [Member] | Citrus County Combined Cycle Facility [Member] | Subsequent Event [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount		$ 200.0
Duke Energy Ohio [Member]
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						$ 131.0	131.0
Public Utilities, Property, Plant and Equipment, Net						6,163.0		6,041.0
Loss Before Income Taxes						37.0	(65.0)
Electric Domestic Regulated Revenue						336.0	337.0
Duke Energy Ohio [Member] | 2017 Ohio Electric Base Rate Case [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						$ 15.0
Requested Return on Equity, Percentage						10.40%
Approved Rate Increase (Decrease), Amount						$ (20.0)
Duke Energy Ohio [Member] | 2017 Ohio Electric Base Rate Case [Member] | PUCO [Member] | Minimum [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						$ (18.0)
Requested Return on Equity, Percentage						9.22%
Duke Energy Ohio [Member] | 2017 Ohio Electric Base Rate Case [Member] | PUCO [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						$ (29.0)
Requested Return on Equity, Percentage						10.24%
Duke Energy Ohio [Member] | 2017 Ohio Electric Base Rate Case [Member] | Subsequent Event [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity, Percentage	9.84%
Public Utilities, Requested Equity Capital Structure, Percentage	50.75%
Public Utilities, Requested Debt Capital Structure, Percentage	49.25%
Requested Rate Increase (Decrease), Amended, Amount	$ (19.0)
Duke Energy Ohio [Member] | 2017 Ohio Electric Base Rate Case [Member] | Subsequent Event [Member] | PUCO [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rider Revenue Increase	10.0
Duke Energy Ohio [Member] | Energy Efficiency Cost Recovery [Member] | PUCO [Member]
Public Utilities, General Disclosures [Line Items]
Electric Domestic Regulated Revenue					$ 20.0
Duke Energy Ohio [Member] | Energy Efficiency Cost Recovery [Member] | PUCO [Member] | Maximum [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount						$ 38.0
Approved Rate Increase (Decrease), One Time Waiver Amount						56.0
Duke Energy Ohio [Member] | Natural Gas Pipeline Extension [Member] | OPSB [Member]
Public Utilities, General Disclosures [Line Items]
Estimated Capital Cost Excluding AFUDC						112.0
Duke Energy Ohio [Member] | Duke Energy Kentucky Rate Case [Member] | KPSC [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						$ 49.0
Requested Rate Increase, Percentage						15.00%
Requested Rate Increase (Decrease), Amended, Amount						$ 30.1
Requested Rate Increase (Decrease), Amended, Percentage						9.00%
Duke Energy Ohio [Member] | Duke Energy Kentucky Rate Case [Member] | Subsequent Event [Member] | KPSC [Member]
Public Utilities, General Disclosures [Line Items]
Approved Rate Increase (Decrease), Amount	$ 8.4
Approved return on equity percentage	9.725%
Public Utilities, Approved Equity Capital Structure, Percentage	49.00%
Total Allocable Capitalization	$ 650.0
Costs recovered through existing riders	50.0
Incremental Rider Revenue	$ 13.0
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						$ 181.0	176.0
Public Utilities, Property, Plant and Equipment, Net						10,345.0		10,286.0
Loss Before Income Taxes						$ (135.0)	(150.0)
Duke Energy Indiana [Member] | Benton County Wind Farm Dispute [Member]
Public Utilities, General Disclosures [Line Items]
Litigation Settlement, Amount Awarded to Other Party				$ 29.0
Duke Energy Indiana [Member] | FERC Transmission Rates [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage						12.38%
Approved Return on Equity Percentage Adder						0.50%
Duke Energy Indiana [Member] | FERC Complaint [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity, Percentage						8.67%
Duke Energy Indiana [Member] | FERC Complaint 1 [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Approved return on equity percentage						10.32%
Duke Energy Indiana [Member] | FERC Complaint 2 [Member] | FERC [Member]
Public Utilities, General Disclosures [Line Items]
Requested Return on Equity, Percentage						9.70%
Piedmont Natural Gas [Member]
Public Utilities, General Disclosures [Line Items]
Utilities Operating Expense, Maintenance, Operations, and Other Costs and Expenses						$ 82.0	77.0
Public Utilities, Property, Plant and Equipment, Net						5,361.0		$ 5,246.0
Loss Before Income Taxes						(145.0)	$ (153.0)
Piedmont Natural Gas [Member] | TPUC IMR Petition Filed November 2017 [Member] | TPUC [Member]
Public Utilities, General Disclosures [Line Items]
Requested Rate Increase (Decrease), Amount						3.3
Requested Rate Increase (Decrease), Amended, Amount						0.4
Storm Costs [Member] | Duke Energy Florida [Member] | Storm Restoration Cost Recovery [Member] | FPSC [Member]
Public Utilities, General Disclosures [Line Items]
Allowed Storm Reserve						$ 132.0

XML

Regulatory Matters (Schedule of Net Carrying Value Of Facilities and Megawatt Capacity) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) MW	Dec. 31, 2017 USD ($)
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net	$ 87,373	$ 86,391
Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net	28,158	27,876
Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net	32,254	31,887
Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net	12,998	12,783
Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Public Utilities, Property, Plant and Equipment, Net	$ 10,345	$ 10,286
Generation Facilities To Be Retired [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	1,738
Public Utilities, Property, Plant and Equipment, Net	$ 391
Allen Steam Station Units 1-3 [Member] | Generation Facilities To Be Retired [Member] | Duke Energy Carolinas [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	585
Public Utilities, Property, Plant and Equipment, Net	$ 161
Crystal River Units 1 and 2 [Member] | Generation Facilities To Be Retired [Member] | Progress Energy [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Public Utilities, Property, Plant and Equipment, Net	$ 104
Crystal River Units 1 and 2 [Member] | Generation Facilities To Be Retired [Member] | Duke Energy Florida [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	873
Public Utilities, Property, Plant and Equipment, Net	$ 104
Gallagher Units 2 and 4 [Member] | Generation Facilities To Be Retired [Member] | Duke Energy Indiana [Member]
Public Utilities, General Disclosures [Line Items]
Capacity (in MW) | MW	280
Public Utilities, Property, Plant and Equipment, Net	$ 126

XML

Commitments and Contingencies (Narrative) (Details)	3 Months Ended
	Mar. 31, 2018 USD ($) plant claim T	Dec. 31, 2017 USD ($)
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual	$ 74,000,000	$ 88,000,000
Coal Ash Insurance Coverage Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Number of NC and SC Plants with Ash Basins | plant	15
NCDEQ State Enforcement Actions [Member]
Valuation and Qualifying Accounts [Abstract]
Number of Plants with No Disputed Facts | plant	7
Number of NC Plants with Ash Basins | plant	14
Number of Plants with Disputed Facts | plant	7
Groundwater Contamination Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Goodwill Payment	$ 5,000
Water Bill Stipend Period	25 years
Duke Energy Carolinas [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual	$ 20,000,000	30,000,000
Duke Energy Carolinas [Member] | Groundwater Contamination Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual	16,000,000
Duke Energy Carolinas [Member] | Asbestos-related Injuries and Damages Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Asbestos-related injuries and damages reserves	487,000,000	489,000,000
Reinsurance retention policy, excess retention, amount reinsured	797,000,000
Probable insurance recoveries	$ 585,000,000	585,000,000
Duke Energy Carolinas [Member] | Asbestos-related Injuries and Damages Claims [Member] | Non-Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim	143
Asbestos-related injuries and damages reserves	$ 37,000,000
Duke Energy Carolinas [Member] | Asbestos-related Injuries and Damages Claims [Member] | Malignant Asbestos Claim [Member]
Valuation and Qualifying Accounts [Abstract]
Loss contingency, pending claims, number | claim	58
Asbestos-related injuries and damages reserves	$ 19,000,000
Progress Energy [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual	51,000,000	55,000,000
Duke Energy Progress [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual	10,000,000	13,000,000
Duke Energy Progress [Member] | Groundwater Contamination Claims [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual	3,000,000
Duke Energy Progress [Member] | Spent Nuclear Fuels [Member]
Valuation and Qualifying Accounts [Abstract]
Gain Contingency, Unrecorded Amount	48,000,000
Litigation Settlement, Amount Awarded from Other Party	$ 48,000,000
Duke Energy Progress [Member] | Gypsum Supply Agreements [Member]
Valuation and Qualifying Accounts [Abstract]
Minimum Amount of Gypsum To Be Supplied | T	50,000
Duke Energy Florida [Member]
Valuation and Qualifying Accounts [Abstract]
Loss Contingency Accrual	$ 24,000,000	$ 24,000,000
Duke Energy Florida [Member] | Spent Nuclear Fuels [Member]
Valuation and Qualifying Accounts [Abstract]
Gain Contingency, Unrecorded Amount	25,000,000
Litigation Settlement, Amount Awarded from Other Party	21,000,000
Duke Energy Florida [Member] | Westinghouse Electric Company Litigation [Member]
Valuation and Qualifying Accounts [Abstract]
Gain Contingency, Unrecorded Amount	54,000,000
Loss Contingency, Damages Sought, Original Amount	510,000,000
Loss Contingency, Damages Awarded, Value	30,000,000
Gain Contingency, Dismissed Amount	54,000,000
Loss Contingency Damages Awarded and Interest, Value	34,000,000
Duke Energy Florida [Member] | MGP Cost Recovery Action [Member]
Valuation and Qualifying Accounts [Abstract]
Gain Contingency, Unrecorded Amount	$ 43,000,000

XML

Commitments and Contingencies (Schedule of Environmental Loss Contingencies) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	$ 57
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	81	$ 98
Provisions/adjustments	4	6
Cash reductions	(5)	(6)
Ending balance	80	98
Duke Energy Carolinas [Member]
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	19
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	10	10
Provisions/adjustments	1	1
Cash reductions	0
Ending balance	11	11
Progress Energy [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	15	18
Provisions/adjustments	3
Cash reductions	(2)	(1)
Ending balance	16	17
Duke Energy Progress [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	3	3
Provisions/adjustments	1
Cash reductions	(1)
Ending balance	3	3
Duke Energy Florida [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	12	14
Provisions/adjustments	1	1
Cash reductions	(1)	(1)
Ending balance	12	14
Duke Energy Ohio [Member]
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	30
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	47	59
Provisions/adjustments		4
Cash reductions	(3)	(4)
Ending balance	44	59
Duke Energy Indiana [Member]
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	5	10
Provisions/adjustments	1	(1)
Cash reductions	0
Ending balance	6	9
Piedmont Natural Gas [Member]
Environmental Matters Details [Line Items]
Environmental Exit Costs, Reasonably Possible Additional Loss	2
Accrual for Environmental Loss Contingencies [Roll Forward]
Beginning balance	2	1
Provisions/adjustments		1
Cash reductions	0
Ending balance	$ 2	$ 2

XML

Commitments and Contingencies (Schedule of Legal Reserves) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Loss Contingencies [Line Items]
Reserves for legal matters	$ 74	$ 88
Duke Energy Carolinas [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	20	30
Progress Energy [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	51	55
Duke Energy Progress [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	10	13
Duke Energy Florida [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	24	24
Piedmont Natural Gas [Member]
Loss Contingencies [Line Items]
Reserves for legal matters	$ 2	$ 2

XML

Debt and Credit Facilities (Narrative) (Details) - USD ($)	May 10, 2018	Mar. 31, 2018
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		$ 8,000,000,000
Revolving Credit Facility [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Expiration Date	Mar. 16, 2023
Three Year Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		1,000,000,000.0
Long-term Line of Credit		500,000,000
Duke Energy Carolinas [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		1,550,000,000
Duke Energy Carolinas [Member] | USDOJ [Member] | North Carolina Ash Basins [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required		250,000,000
Duke Energy Progress [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Facility size		1,250,000,000
Duke Energy Progress [Member] | USDOJ [Member] | North Carolina Ash Basins [Member] | Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Minimum Master Credit Facility Balance Required		$ 250,000,000

XML

Debt and Credit Facilities (Summary of Debt Issuances) (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Debt issuances	$ 1,250,000,000
Current maturities of long-term debt	3,951,000,000	$ 3,244,000,000
Parent Company [Member]
Debt Instrument [Line Items]
Debt issuances	250,000,000
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Debt issuances	1,000,000,000
Current maturities of long-term debt	805,000,000	$ 1,205,000,000
Duke Energy Carolinas [Member] | Bonds Maturing April 2018, 5.100% Coupon [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	300,000,000
Unsecured Debt [Member] | March 2018 Debt Issuance 3.950% Coupon Due 2025 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 250,000,000
Interest rate	3.95%
Unsecured Debt [Member] | Parent Company [Member] | March 2018 Debt Issuance 3.950% Coupon Due 2025 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 250,000,000
First Mortgage [Member] | March 2018 Debt Issuance 3.050% Coupon [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
Interest rate	3.05%
First Mortgage [Member] | March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
Interest rate	3.95%
First Mortgage [Member] | Duke Energy Carolinas [Member] | March 2018 Debt Issuance 3.050% Coupon [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
First Mortgage [Member] | Duke Energy Carolinas [Member] | March 2018 Debt Issuance 3.950% Coupon Due 2048 [Member]
Debt Instrument [Line Items]
Debt issuances	$ 500,000,000
First Mortgage [Member] | Duke Energy Carolinas [Member] | Bonds Maturing April 2018, 5.100% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	5.10%
Current maturities of long-term debt	$ 300,000,000

XML

Debt and Credit Facilities (Summary of Current Maturities of Long-term Debt)(Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 3,951,000,000	$ 3,244,000,000
Other Debt Obligations [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 601,000,000
Parent Company [Member] | Unsecured Debt [Member] | Debt Maturing June 2018, 6.250% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	6.25%
Current maturities of long-term debt	$ 250,000,000
Parent Company [Member] | Unsecured Debt [Member] | Debt Maturing June 2018, 2.100% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	2.10%
Current maturities of long-term debt	$ 500,000,000
Piedmont Natural Gas [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 250,000,000	250,000,000
Piedmont Natural Gas [Member] | Unsecured Debt [Member] | Debt Maturing December 2018, Floating Rate [Member]
Debt Instrument [Line Items]
Interest rate	2.821%
Current maturities of long-term debt	$ 250,000,000
Progress Energy [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 1,820,000,000	771,000,000
Progress Energy [Member] | Unsecured Debt [Member] | Debt Maturing March 2019, 7.050% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	7.05%
Current maturities of long-term debt	$ 450,000,000
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	805,000,000	1,205,000,000
Duke Energy Carolinas [Member] | Bonds Maturing April 2018, 5.100% Coupon [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 300,000,000
Duke Energy Carolinas [Member] | First Mortgage Bonds [Member] | Bonds Maturing April 2018, 5.100% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	5.10%
Current maturities of long-term debt	$ 300,000,000
Duke Energy Carolinas [Member] | First Mortgage Bonds [Member] | Bonds Maturing November 2018, 7.000% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	7.00%
Current maturities of long-term debt	$ 500,000,000
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 768,000,000	768,000,000
Duke Energy Florida [Member] | First Mortgage Bonds [Member] | Bonds Maturing June 2018, 5.650% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	5.65%
Current maturities of long-term debt	$ 500,000,000
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Current maturities of long-term debt	$ 603,000,000	$ 3,000,000
Duke Energy Progress [Member] | First Mortgage Bonds [Member] | Bonds Maturing January 2019, 5.300% Coupon [Member]
Debt Instrument [Line Items]
Interest rate	5.30%
Current maturities of long-term debt	$ 600,000,000

XML

Debt and Credit Facilities (Schedule of Line of Credit Facilities) (Details) - Revolving Credit Facility [Member]	Mar. 31, 2018 USD ($)
Line of Credit Facility [Line Items]
Facility size	$ 8,000,000,000
Commercial paper	(2,602,000,000)
Outstanding letters of credit	(59,000,000)
Tax exempt bonds	(81,000,000)
Coal ash set-aside	(500,000,000)
Available capacity	4,758,000,000
Parent Company [Member]
Line of Credit Facility [Line Items]
Facility size	2,650,000,000
Commercial paper	(1,281,000,000)
Outstanding letters of credit	(50,000,000)
Available capacity	1,319,000,000
Duke Energy Carolinas [Member]
Line of Credit Facility [Line Items]
Facility size	1,550,000,000
Commercial paper	(340,000,000)
Outstanding letters of credit	(4,000,000)
Coal ash set-aside	(250,000,000)
Available capacity	956,000,000
Duke Energy Progress [Member]
Line of Credit Facility [Line Items]
Facility size	1,250,000,000
Commercial paper	(464,000,000)
Outstanding letters of credit	(2,000,000)
Coal ash set-aside	(250,000,000)
Available capacity	534,000,000
Duke Energy Florida [Member]
Line of Credit Facility [Line Items]
Facility size	800,000,000
Outstanding letters of credit	(1,000,000)
Available capacity	799,000,000
Duke Energy Ohio [Member]
Line of Credit Facility [Line Items]
Facility size	450,000,000
Commercial paper	(140,000,000)
Available capacity	310,000,000
Duke Energy Indiana [Member]
Line of Credit Facility [Line Items]
Facility size	600,000,000
Commercial paper	(282,000,000)
Tax exempt bonds	(81,000,000)
Available capacity	237,000,000
Piedmont Natural Gas [Member]
Line of Credit Facility [Line Items]
Facility size	700,000,000
Commercial paper	(95,000,000)
Outstanding letters of credit	(2,000,000)
Available capacity	603,000,000
Proceeds Loaned To Subsidiary Registrants [Member] | Parent Company [Member]
Line of Credit Facility [Line Items]
Commercial paper	$ (625,000,000)

XML

Goodwill (Details) - USD ($)	Mar. 31, 2018	Dec. 31, 2017
Goodwill [Line Items]
Goodwill balance	$ 19,425,000,000	$ 19,425,000,000
Accumulated impairment charges	(29,000,000)	(29,000,000)
Goodwill, adjusted for accumulated impairment charges	19,396,000,000	19,396,000,000
Electric Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill balance	17,379,000,000	17,379,000,000
Goodwill, adjusted for accumulated impairment charges	17,379,000,000	17,379,000,000
Gas Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill balance	1,924,000,000	1,924,000,000
Goodwill, adjusted for accumulated impairment charges	1,924,000,000	1,924,000,000
Commercial Renewables [Member]
Goodwill [Line Items]
Goodwill balance	122,000,000	122,000,000
Accumulated impairment charges	(29,000,000)	(29,000,000)
Goodwill, adjusted for accumulated impairment charges	93,000,000	93,000,000
Duke Energy Ohio [Member]
Goodwill [Line Items]
Accumulated impairment charges	(216,000,000)	(216,000,000)
Goodwill, adjusted for accumulated impairment charges	920,000,000	920,000,000
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill, adjusted for accumulated impairment charges	596,000,000	596,000,000
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Goodwill [Line Items]
Goodwill, adjusted for accumulated impairment charges	324,000,000	324,000,000
Progress Energy [Member]
Goodwill [Line Items]
Accumulated impairment charges	0	0
Goodwill, adjusted for accumulated impairment charges	3,655,000,000	3,655,000,000
Piedmont Natural Gas [Member]
Goodwill [Line Items]
Accumulated impairment charges	0	0
Goodwill, adjusted for accumulated impairment charges	$ 49,000,000	$ 49,000,000

XML

Related Party Transactions (Other Revenue and Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Duke Energy Carolinas [Member] | Corporate Governance And Shared Service Expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 220	$ 221
Duke Energy Carolinas [Member] | Indemnification Coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	6	6
Duke Energy Carolinas [Member] | Joint Dispatch Agreement [Member] | Duke Energy Progress [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	34	16
Related party transaction, expenses from transactions with related party	54	31
Duke Energy Carolinas [Member] | Intercompany Natural Gas Transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	4	1
Progress Energy [Member] | Corporate Governance And Shared Service Expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	191	170
Progress Energy [Member] | Indemnification Coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	8	10
Progress Energy [Member] | Joint Dispatch Agreement [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	54	31
Related party transaction, expenses from transactions with related party	34	16
Progress Energy [Member] | Intercompany Natural Gas Transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	19
Duke Energy Progress [Member] | Corporate Governance And Shared Service Expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	118	100
Duke Energy Progress [Member] | Indemnification Coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	3	4
Duke Energy Progress [Member] | Joint Dispatch Agreement [Member] | Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	54	31
Related party transaction, expenses from transactions with related party	34	16
Duke Energy Progress [Member] | Intercompany Natural Gas Transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	19	19
Duke Energy Florida [Member] | Corporate Governance And Shared Service Expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	73	70
Duke Energy Florida [Member] | Indemnification Coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	5	6
Duke Energy Ohio [Member] | Corporate Governance And Shared Service Expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	89	92
Duke Energy Ohio [Member] | Indemnification Coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1
Duke Energy Indiana [Member] | Corporate Governance And Shared Service Expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	101	95
Duke Energy Indiana [Member] | Indemnification Coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	2	2
Piedmont Natural Gas [Member] | Corporate Governance And Shared Service Expenses [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	36	5
Piedmont Natural Gas [Member] | Indemnification Coverages [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	1	1
Piedmont Natural Gas [Member] | Intercompany Natural Gas Transactions [Member] | Affiliated Entity [Member]
Related Party Transaction [Line Items]
Related party transaction, other revenues from transactions with related party	$ 23	$ 20

XML

Related Party Transactions (Equity Method Investments) (Details) - Piedmont Natural Gas [Member] - Equity Method Investee [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 6	$ 6
Accounts Payable, Related Parties, Current	2		$ 2
Cardinal Pipeline Company, LLC [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	2	2
Pine Needle LNG Company, LLC [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	2	2
Hardy Storage Company, LLC [Member]
Related Party Transaction [Line Items]
Related party transaction, expenses from transactions with related party	$ 2	$ 2

XML

Related Party Transactions (Intercompany Income Taxes) (Details) - Affiliated Entity [Member] - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Duke Energy Carolinas [Member]
Related Party Transaction [Line Items]
Income tax payable	$ 9	$ 44
Progress Energy [Member]
Related Party Transaction [Line Items]
Income taxes receivable	183	168
Duke Energy Progress [Member]
Related Party Transaction [Line Items]
Income taxes receivable	13
Income tax payable		21
Duke Energy Florida [Member]
Related Party Transaction [Line Items]
Income taxes receivable	9	44
Duke Energy Ohio [Member]
Related Party Transaction [Line Items]
Income taxes receivable		22
Income tax payable	3
Duke Energy Indiana [Member]
Related Party Transaction [Line Items]
Income tax payable	18	35
Piedmont Natural Gas [Member]
Related Party Transaction [Line Items]
Income taxes receivable		$ 7
Income tax payable	$ 43

XML

Derivatives and Hedging (Notional Amounts of Derivative Instruments) (Details) Mcf in Millions, $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018 USD ($) GWh Mcf	Dec. 31, 2017 USD ($) GWh Mcf
Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	16	34
Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Mcf	765	770
Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 1,187	$ 1,587
Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	660	660
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	527	927
Variable Interest Entity, Primary Beneficiary [Member] | Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 660	$ 660
Duke Energy Carolinas [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Mcf	110	105
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount		$ 400
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount		$ 400
Progress Energy [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Mcf	179	183
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 500	$ 500
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 500	$ 500
Duke Energy Progress [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Mcf	149	133
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 250	$ 250
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 250	$ 250
Duke Energy Florida [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Mcf	30	50
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 250	$ 250
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	250	250
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	27	27
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member]
Derivative [Line Items]
Notional amount	$ 27	$ 27
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Electricity [Member]
Derivative [Line Items]
Notional amount, energy measure, in gigawatt-hours | GWh	16	34
Duke Energy Indiana [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Mcf	2	2
Piedmont Natural Gas [Member] | Commodity Contracts [Member] | Natural Gas [Member]
Derivative [Line Items]
Notional amount, volume, in millions of decatherms | Mcf	474	480

XML

Derivatives and Hedging (Location and Fair Value Amounts of Derivatives Reflected in the Condensed Consolidated Balance Sheets) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	$ 37	$ 51
Location and fair value amounts of derivatives (Liability)	190	230
Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15	35
Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	22	16
Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	33	66
Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	157	164
Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	15	35
Location and fair value amounts of derivatives (Liability)	166	182
Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	22	16
Location and fair value amounts of derivatives (Liability)	24	48
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	21	15
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	29
Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	6
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	14	34
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	26	36
Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	140	146
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	1
Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	14	12
Duke Energy Carolinas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Location and fair value amounts of derivatives (Liability)	11	35
Duke Energy Carolinas [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Duke Energy Carolinas [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5	31
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6	4
Duke Energy Carolinas [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Location and fair value amounts of derivatives (Liability)	11	10
Duke Energy Carolinas [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		25
Duke Energy Carolinas [Member] | Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		25
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	5	6
Duke Energy Carolinas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6	4
Progress Energy [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	3
Location and fair value amounts of derivatives (Liability)	37	36
Progress Energy [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	2
Progress Energy [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Progress Energy [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	11	19
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	26	17
Progress Energy [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	3
Location and fair value amounts of derivatives (Liability)	23	28
Progress Energy [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	14	8
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	3	2
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	18
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	15	10
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	1
Progress Energy [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	11	7
Duke Energy Progress [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Location and fair value amounts of derivatives (Liability)	21	18
Duke Energy Progress [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	1
Duke Energy Progress [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		1
Duke Energy Progress [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	8	8
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	13	10
Duke Energy Progress [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	2
Location and fair value amounts of derivatives (Liability)	12	12
Duke Energy Progress [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	9	6
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	2	1
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Noncurrent Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	0	1
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6	8
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	6	4
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	2
Duke Energy Progress [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	7	6
Duke Energy Florida [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Location and fair value amounts of derivatives (Liability)	7	12
Duke Energy Florida [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Duke Energy Florida [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	10
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	2
Duke Energy Florida [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Location and fair value amounts of derivatives (Liability)	3	10
Duke Energy Florida [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	2
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	10
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	1
Duke Energy Florida [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	3	2
Duke Energy Ohio [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Location and fair value amounts of derivatives (Liability)	4	5
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Duke Energy Ohio [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	4
Duke Energy Ohio [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Duke Energy Ohio [Member] | Interest Rate Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	5
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	1
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)		1
Duke Energy Ohio [Member] | Not Designated as Hedging Instrument [Member] | Interest Rate Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	4	4
Duke Energy Indiana [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	27
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	27
Duke Energy Indiana [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	27
Duke Energy Indiana [Member] | Designated As Hedging Instrument [Member] | Interest Rate Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)		0
Duke Energy Indiana [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	7	27
Piedmont Natural Gas [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Location and fair value amounts of derivatives (Liability)	132	142
Piedmont Natural Gas [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Piedmont Natural Gas [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	13	11
Piedmont Natural Gas [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	119	131
Piedmont Natural Gas [Member] | Commodity Contracts [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Location and fair value amounts of derivatives (Liability)	132	142
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Assets, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Asset)	1	2
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Current Liabilities, Other [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	13	11
Piedmont Natural Gas [Member] | Not Designated as Hedging Instrument [Member] | Commodity Contracts [Member] | Other Noncurrent Liabilities [Member]
Derivatives, Fair Value [Line Items]
Location and fair value amounts of derivatives (Liability)	$ 119	$ 131

XML

Derivatives and Hedging (Schedule of Offsetting Assets) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	$ 37	$ 51
Net amounts recognized on the Condensed Consolidated Balance Sheet	37	51
Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	15	35
Gross amounts offset	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	13	35
Noncurrent Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	22	16
Net amounts recognized on the Condensed Consolidated Balance Sheet	22	16
Duke Energy Carolinas [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	2
Duke Energy Carolinas [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	2
Gross amounts offset	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	2
Progress Energy [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3	3
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	3
Progress Energy [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	3	2
Gross amounts offset	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	2
Progress Energy [Member] | Noncurrent Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Duke Energy Progress [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	2	2
Duke Energy Progress [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	2	1
Gross amounts offset	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Progress [Member] | Noncurrent Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Duke Energy Florida [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Florida [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Ohio [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Ohio [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	1
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	1
Duke Energy Indiana [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	27
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	27
Duke Energy Indiana [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	7	27
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	27
Piedmont Natural Gas [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	1	2
Piedmont Natural Gas [Member] | Current Assets, Other [Member]
Offsetting Derivative Assets [Abstract]
Gross amounts recognized	1	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 1	$ 2

XML

Derivatives and Hedging (Schedule of Offsetting Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	$ 190	$ 230
Net amounts recognized on the Condensed Consolidated Balance Sheet	190	230
Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	33	66
Gross amounts offset	(4)	(3)
Net amounts recognized on the Condensed Consolidated Balance Sheet	29	63
Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	157	164
Gross amounts offset	(1)	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	156	163
Duke Energy Carolinas [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	11	35
Net amounts recognized on the Condensed Consolidated Balance Sheet	11	35
Duke Energy Carolinas [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	5	31
Gross amounts offset	(2)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	29
Duke Energy Carolinas [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	6	4
Net amounts recognized on the Condensed Consolidated Balance Sheet	6	4
Progress Energy [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	37	36
Net amounts recognized on the Condensed Consolidated Balance Sheet	37	36
Progress Energy [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	11	19
Gross amounts offset	(2)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	9	17
Progress Energy [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	26	17
Gross amounts offset	(1)	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	25	16
Duke Energy Progress [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	21	18
Net amounts recognized on the Condensed Consolidated Balance Sheet	21	18
Duke Energy Progress [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	8	8
Gross amounts offset	(2)	(2)
Net amounts recognized on the Condensed Consolidated Balance Sheet	6	6
Duke Energy Progress [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	13	10
Gross amounts offset	(1)	(1)
Net amounts recognized on the Condensed Consolidated Balance Sheet	12	9
Duke Energy Florida [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	7	12
Net amounts recognized on the Condensed Consolidated Balance Sheet	7	12
Duke Energy Florida [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	4	10
Net amounts recognized on the Condensed Consolidated Balance Sheet	4	10
Duke Energy Florida [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	3	2
Net amounts recognized on the Condensed Consolidated Balance Sheet	3	2
Duke Energy Ohio [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	4	5
Net amounts recognized on the Condensed Consolidated Balance Sheet	4	5
Duke Energy Ohio [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized		1
Net amounts recognized on the Condensed Consolidated Balance Sheet		1
Duke Energy Ohio [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	4	4
Net amounts recognized on the Condensed Consolidated Balance Sheet	4	4
Piedmont Natural Gas [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	132	142
Net amounts recognized on the Condensed Consolidated Balance Sheet	132	142
Piedmont Natural Gas [Member] | Other Current Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	13	11
Net amounts recognized on the Condensed Consolidated Balance Sheet	13	11
Piedmont Natural Gas [Member] | Other Noncurrent Liabilities [Member]
Offsetting Derivative Liabilities [Abstract]
Gross amounts recognized	119	131
Net amounts recognized on the Condensed Consolidated Balance Sheet	$ 119	$ 131

XML

Derivatives and Hedging (Derivative Instruments with Credit-Risk Related Contingent Features and Cash Collateral) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	$ 30	$ 59
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	30	59
Duke Energy Carolinas [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	10	35
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	10	35
Progress Energy [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	20	25
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	20	25
Duke Energy Progress [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	18	15
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	18	15
Duke Energy Florida [Member]
Schedule of Information Regarding Derivative Instruments That Contain Credit-Risk Related Contingent Features
Aggregate fair value amounts of derivative instruments in a net liability position	2	10
Additional cash collateral or letters of credit in the event credit-risk-related contingent features were triggered	$ 2	$ 10

XML

Investments in Debt and Equity Securities (All Debt and Equity Securities Through OCI and FV-NI - ASU 2016-01) (Details) $ in Millions	Mar. 31, 2018 USD ($)
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	$ 2,823
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	74
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	7,414
Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	2,765
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	71
Cash and cash equivalents	143
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	7,026
Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	58
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	3
Cash and cash equivalents	15
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	388
Duke Energy Carolinas [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,507
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	39
Cash and cash equivalents	50
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	3,737
Progress Energy [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,259
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	32
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	3,346
Progress Energy [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1,258
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	32
Cash and cash equivalents	93
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	3,289
Progress Energy [Member] | Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1
Cash and cash equivalents	10
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	57
Duke Energy Progress [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	966
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	25
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2,572
Duke Energy Progress [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	966
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	25
Cash and cash equivalents	59
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	2,571
Duke Energy Progress [Member] | Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Cash and cash equivalents	1
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	1
Duke Energy Florida [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	293
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	7
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	765
Duke Energy Florida [Member] | Ndtf [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	292
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	7
Cash and cash equivalents	34
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	718
Duke Energy Florida [Member] | Other Classification [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	1
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	47
Duke Energy Indiana [Member]
Schedule Of Available For Sale Securities And Other Trading Assets [Line Items]
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Gain	48
Debt Securities, Available-for-sale, and Equity Securities, FV-NI, Unrealized Loss	1
Debt Securities, Available-for-sale, and Equity Securities, FV-NI	$ 127

XML

Investments in Debt and Equity Securities (Equity Securities, FV-NI - ASU 2016-01) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Realized Gain	$ 19
Equity Securities, FV-NI, Realized Loss	13
Ndtf [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI, Unrealized Gain	2,751
Equity Securities, FV-NI, Unrealized Loss	38
Equity Securities, FV-NI	4,857
Other Classification [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI, Unrealized Gain	57
Equity Securities, FV-NI	130
Duke Energy Carolinas [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Realized Gain	10
Equity Securities, FV-NI, Realized Loss	5
Duke Energy Carolinas [Member] | Ndtf [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI, Unrealized Gain	1,502
Equity Securities, FV-NI, Unrealized Loss	20
Equity Securities, FV-NI	2,669
Progress Energy [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Realized Gain	9
Equity Securities, FV-NI, Realized Loss	8
Progress Energy [Member] | Ndtf [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI, Unrealized Gain	1,249
Equity Securities, FV-NI, Unrealized Loss	18
Equity Securities, FV-NI	2,188
Duke Energy Progress [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Realized Gain	8
Equity Securities, FV-NI, Realized Loss	8
Duke Energy Progress [Member] | Ndtf [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI, Unrealized Gain	959
Equity Securities, FV-NI, Unrealized Loss	14
Equity Securities, FV-NI	1,765
Duke Energy Florida [Member]
Equity Securities, FV-NI, Realized Gain (Loss) [Abstract]
Equity Securities, FV-NI, Realized Gain	1
Duke Energy Florida [Member] | Ndtf [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI, Unrealized Gain	290
Equity Securities, FV-NI, Unrealized Loss	4
Equity Securities, FV-NI	423
Duke Energy Indiana [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI, Unrealized Gain	48
Equity Securities, FV-NI	96
Duke Energy Indiana [Member] | Other Classification [Member]
EquitySecuritiesFvNiAccumulatedUnrealizedGainLoss [Abstract]
Equity Securities, FV-NI	$ 96

XML

Investments in Debt Securities and Equity Securities (Available-for-sale, OCI - ASU 2016-01) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	$ 2,269
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt Securities, Available-for-Sale, Realized Gain	5
Debt Securities, Available-for-sale, Realized Loss	13
Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	2,169
Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	258
Corporate Debt Securities [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	7
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	8
Available-for-sale Securities, Debt Securities	549
Corporate Debt Securities [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1
Available-for-sale Securities, Debt Securities	64
Municipal Bonds [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	5
Available-for-sale Securities, Debt Securities	333
Municipal Bonds [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1
Available-for-sale Securities, Debt Securities	80
US Treasury and Government [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	6
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	18
Available-for-sale Securities, Debt Securities	1,014
US Treasury and Government [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1
Available-for-sale Securities, Debt Securities	51
Other Debt Obligations [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2
Available-for-sale Securities, Debt Securities	130
Other Debt Obligations [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	48
Duke Energy Carolinas [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	1,018
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt Securities, Available-for-Sale, Realized Gain	5
Debt Securities, Available-for-sale, Realized Loss	10
Duke Energy Carolinas [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	1,068
Duke Energy Carolinas [Member] | Corporate Debt Securities [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	5
Available-for-sale Securities, Debt Securities	333
Duke Energy Carolinas [Member] | Municipal Bonds [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1
Available-for-sale Securities, Debt Securities	69
Duke Energy Carolinas [Member] | US Treasury and Government [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	2
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	11
Available-for-sale Securities, Debt Securities	494
Duke Energy Carolinas [Member] | Other Debt Obligations [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2
Available-for-sale Securities, Debt Securities	122
Progress Energy [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	1,055
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt Securities, Available-for-sale, Realized Loss	3
Progress Energy [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	1,101
Progress Energy [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	57
Progress Energy [Member] | Corporate Debt Securities [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	4
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	3
Available-for-sale Securities, Debt Securities	216
Progress Energy [Member] | Municipal Bonds [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	4
Available-for-sale Securities, Debt Securities	264
Progress Energy [Member] | Municipal Bonds [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Available-for-sale Securities, Debt Securities	47
Progress Energy [Member] | US Treasury and Government [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	4
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	7
Available-for-sale Securities, Debt Securities	520
Progress Energy [Member] | Other Debt Obligations [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	8
Duke Energy Progress [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	747
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt Securities, Available-for-sale, Realized Loss	2
Duke Energy Progress [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	806
Duke Energy Progress [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	1
Duke Energy Progress [Member] | Corporate Debt Securities [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2
Available-for-sale Securities, Debt Securities	153
Duke Energy Progress [Member] | Municipal Bonds [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	4
Available-for-sale Securities, Debt Securities	263
Duke Energy Progress [Member] | US Treasury and Government [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	3
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	5
Available-for-sale Securities, Debt Securities	326
Duke Energy Progress [Member] | Other Debt Obligations [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	5
Duke Energy Florida [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	308
Debt Securities, Available-for-sale, Realized Gain (Loss) [Abstract]
Debt Securities, Available-for-sale, Realized Loss	1
Duke Energy Florida [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	295
Duke Energy Florida [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	47
Duke Energy Florida [Member] | Corporate Debt Securities [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1
Available-for-sale Securities, Debt Securities	63
Duke Energy Florida [Member] | Municipal Bonds [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	1
Duke Energy Florida [Member] | Municipal Bonds [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Available-for-sale Securities, Debt Securities	47
Duke Energy Florida [Member] | US Treasury and Government [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain, before Tax	1
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	2
Available-for-sale Securities, Debt Securities	194
Duke Energy Florida [Member] | Other Debt Obligations [Member] | Ndtf [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	3
Duke Energy Indiana [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	31
Duke Energy Indiana [Member] | Other Classification [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	31
Duke Energy Indiana [Member] | Corporate Debt Securities [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Available-for-sale Securities, Debt Securities	5
Duke Energy Indiana [Member] | Municipal Bonds [Member]
Available-for-sale Securities, Accumulated Gross Unrealized Gain (Loss), before Tax [Abstract]
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Loss, before Tax	1
Available-for-sale Securities, Debt Securities	$ 26

XML

Investments in Debt and Equity Securities (Available-For-Sale Investments) (Details) $ in Millions	Dec. 31, 2017 USD ($)
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	$ 2,899
Gross Unrealized Holding Losses	42
Estimated Fair Value	7,451
Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2,837
Gross Unrealized Holding Losses	40
Estimated Fair Value	7,088
Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	115
Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2,805
Gross Unrealized Holding Losses	27
Estimated Fair Value	4,914
Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	17
Gross Unrealized Holding Losses	2
Estimated Fair Value	570
Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4
Gross Unrealized Holding Losses	3
Estimated Fair Value	344
Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	11
Gross Unrealized Holding Losses	7
Estimated Fair Value	1,027
Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1
Estimated Fair Value	118
Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	62
Gross Unrealized Holding Losses	2
Estimated Fair Value	363
Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	15
Other Classification [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	59
Estimated Fair Value	123
Other Classification [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1
Estimated Fair Value	57
Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2
Gross Unrealized Holding Losses	1
Estimated Fair Value	83
Other Classification [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	41
Other Classification [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1
Estimated Fair Value	44
Duke Energy Carolinas [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,543
Gross Unrealized Holding Losses	20
Estimated Fair Value	3,758
Duke Energy Carolinas [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	32
Duke Energy Carolinas [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,531
Gross Unrealized Holding Losses	12
Estimated Fair Value	2,692
Duke Energy Carolinas [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	9
Gross Unrealized Holding Losses	2
Estimated Fair Value	359
Duke Energy Carolinas [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1
Estimated Fair Value	60
Duke Energy Carolinas [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3
Gross Unrealized Holding Losses	4
Estimated Fair Value	503
Duke Energy Carolinas [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1
Estimated Fair Value	112
Progress Energy [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,296
Gross Unrealized Holding Losses	20
Estimated Fair Value	3,389
Progress Energy [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,294
Gross Unrealized Holding Losses	20
Estimated Fair Value	3,330
Progress Energy [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	83
Progress Energy [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	1,274
Gross Unrealized Holding Losses	15
Estimated Fair Value	2,222
Progress Energy [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	8
Estimated Fair Value	211
Progress Energy [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4
Gross Unrealized Holding Losses	2
Estimated Fair Value	284
Progress Energy [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	8
Gross Unrealized Holding Losses	3
Estimated Fair Value	524
Progress Energy [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	6
Progress Energy [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2
Estimated Fair Value	59
Progress Energy [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	12
Progress Energy [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2
Estimated Fair Value	47
Duke Energy Progress [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	995
Gross Unrealized Holding Losses	16
Estimated Fair Value	2,592
Duke Energy Progress [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	995
Gross Unrealized Holding Losses	16
Estimated Fair Value	2,591
Duke Energy Progress [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	50
Duke Energy Progress [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	980
Gross Unrealized Holding Losses	12
Estimated Fair Value	1,795
Duke Energy Progress [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	6
Estimated Fair Value	149
Duke Energy Progress [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	4
Gross Unrealized Holding Losses	2
Estimated Fair Value	283
Duke Energy Progress [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	5
Gross Unrealized Holding Losses	2
Estimated Fair Value	310
Duke Energy Progress [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	4
Duke Energy Progress [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1
Duke Energy Progress [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1
Duke Energy Florida [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	301
Gross Unrealized Holding Losses	4
Estimated Fair Value	787
Duke Energy Florida [Member] | Ndtf [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	299
Gross Unrealized Holding Losses	4
Estimated Fair Value	739
Duke Energy Florida [Member] | Ndtf [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	33
Duke Energy Florida [Member] | Ndtf [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	294
Gross Unrealized Holding Losses	3
Estimated Fair Value	427
Duke Energy Florida [Member] | Ndtf [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2
Estimated Fair Value	62
Duke Energy Florida [Member] | Ndtf [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1
Duke Energy Florida [Member] | Ndtf [Member] | US Treasury and Government [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	3
Gross Unrealized Holding Losses	1
Estimated Fair Value	214
Duke Energy Florida [Member] | Ndtf [Member] | Other Debt Obligations [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	2
Duke Energy Florida [Member] | Other Classification [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2
Estimated Fair Value	48
Duke Energy Florida [Member] | Other Classification [Member] | Cash and Cash Equivalents [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	1
Duke Energy Florida [Member] | Other Classification [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	2
Estimated Fair Value	47
Duke Energy Indiana [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	49
Gross Unrealized Holding Losses	1
Estimated Fair Value	128
Duke Energy Indiana [Member] | Equity Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Gains	49
Estimated Fair Value	97
Duke Energy Indiana [Member] | Corporate Debt Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Estimated Fair Value	3
Duke Energy Indiana [Member] | Municipal Bonds [Member]
Schedule of Available-for-sale Securities [Line Items]
Gross Unrealized Holding Losses	1
Estimated Fair Value	$ 28

XML

Investments in Debt and Equity Securities (Maturities) (Details) $ in Millions	Mar. 31, 2018 USD ($)
Debt Instrument [Line Items]
Due in one year or less	$ 100
Due after one through five years	535
Due after five through 10 years	530
Due after 10 years	1,104
Total	2,269
Duke Energy Carolinas [Member]
Debt Instrument [Line Items]
Due in one year or less	11
Due after one through five years	178
Due after five through 10 years	285
Due after 10 years	544
Total	1,018
Progress Energy [Member]
Debt Instrument [Line Items]
Due in one year or less	75
Due after one through five years	300
Due after five through 10 years	198
Due after 10 years	482
Total	1,055
Duke Energy Progress [Member]
Debt Instrument [Line Items]
Due in one year or less	19
Due after one through five years	216
Due after five through 10 years	144
Due after 10 years	368
Total	747
Duke Energy Florida [Member]
Debt Instrument [Line Items]
Due in one year or less	56
Due after one through five years	84
Due after five through 10 years	54
Due after 10 years	114
Total	308
Duke Energy Indiana [Member]
Debt Instrument [Line Items]
Due in one year or less	3
Due after one through five years	15
Due after five through 10 years	6
Due after 10 years	7
Total	$ 31

XML

Investments in Debt and Equity Securities (Realized Gains and Losses)(Details) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($)
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	$ 93
Realized losses	62
Duke Energy Carolinas [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	66
Realized losses	40
Progress Energy [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	27
Realized losses	21
Duke Energy Progress [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	24
Realized losses	19
Duke Energy Florida [Member]
Available-for-sale Securities, Gross Realized Gain (Loss) [Abstract]
Realized gains	3
Realized losses	$ 2

XML

Fair Value Measurements (Fair Value Measurement Amounts for Assets and Liabilities) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative Investment, Fair Value Disclosure	$ 72	$ 74
Available-for-sale Securities, Debt Securities	2,269
Derivative assets	37	51
Total assets	7,451	7,503
Derivative liabilities	(190)	(230)
Net assets (liabilities)	7,261	7,273
Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	3
Total assets	5,616	5,658
Derivative liabilities	(1)	(2)
Net assets (liabilities)	5,615	5,656
Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	27	20
Total assets	1,755	1,743
Derivative liabilities	(57)	(86)
Net assets (liabilities)	1,698	1,657
Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	8	28
Total assets	8	28
Derivative liabilities	(132)	(142)
Net assets (liabilities)	(124)	(114)
Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	4,857
Available-for-sale Securities, Debt Securities	2,169
Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	4,785
Available-for-sale Securities, Debt Securities	633
Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	1,536
Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	130
Available-for-sale Securities, Debt Securities	258
Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	130
Available-for-sale Securities, Debt Securities	66
Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	192
Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative Investment, Fair Value Disclosure	72	74
Investments, Fair Value Disclosure		4,914
Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		4,840
Equity Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		123
Equity Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		123
Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		2,174
Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		635
Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1,539
Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		241
Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		57
Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		184
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative Investment, Fair Value Disclosure	72	74
Available-for-sale Securities, Debt Securities	1,018
Derivative assets	2	2
Total assets	3,739	3,760
Derivative liabilities	(11)	(35)
Net assets (liabilities)	3,728	3,725
Duke Energy Carolinas [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0
Total assets	2,806	2,822
Derivative liabilities	(1)	(1)
Net assets (liabilities)	2,805	2,821
Duke Energy Carolinas [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	2
Total assets	861	864
Derivative liabilities	(10)	(34)
Net assets (liabilities)	851	830
Duke Energy Carolinas [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	2,669
Available-for-sale Securities, Debt Securities	1,068
Duke Energy Carolinas [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	2,597
Available-for-sale Securities, Debt Securities	209
Duke Energy Carolinas [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	859
Duke Energy Carolinas [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Alternative Investment, Fair Value Disclosure	72	74
Investments, Fair Value Disclosure		2,692
Duke Energy Carolinas [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		2,618
Duke Energy Carolinas [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1,066
Duke Energy Carolinas [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		204
Duke Energy Carolinas [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		862
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	1,055
Derivative assets	3	3
Total assets	3,349	3,392
Derivative liabilities	(37)	(36)
Net assets (liabilities)	3,312	3,356
Progress Energy [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	1
Total assets	2,622	2,666
Derivative liabilities	(1)	(1)
Net assets (liabilities)	2,621	2,665
Progress Energy [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	3	2
Total assets	727	726
Derivative liabilities	(36)	(35)
Net assets (liabilities)	691	691
Progress Energy [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	2,188
Available-for-sale Securities, Debt Securities	1,101
Progress Energy [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	2,188
Available-for-sale Securities, Debt Securities	424
Progress Energy [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	677
Progress Energy [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	57
Progress Energy [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	10
Progress Energy [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	47
Progress Energy [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		2,222
Progress Energy [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		2,222
Progress Energy [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1,108
Progress Energy [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		431
Progress Energy [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		677
Progress Energy [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		59
Progress Energy [Member] | Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		12
Progress Energy [Member] | Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		47
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	747
Derivative assets	2	2
Total assets	2,574	2,594
Derivative liabilities	(21)	(18)
Net assets (liabilities)	2,553	2,576
Duke Energy Progress [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0	1
Total assets	2,020	2,040
Derivative liabilities	(1)	(1)
Net assets (liabilities)	2,019	2,039
Duke Energy Progress [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	2	1
Total assets	554	554
Derivative liabilities	(20)	(17)
Net assets (liabilities)	534	537
Duke Energy Progress [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	1,765
Available-for-sale Securities, Debt Securities	806
Duke Energy Progress [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	1,765
Available-for-sale Securities, Debt Securities	254
Duke Energy Progress [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	552
Duke Energy Progress [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	1
Duke Energy Progress [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	1
Duke Energy Progress [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1,795
Duke Energy Progress [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1,795
Duke Energy Progress [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		796
Duke Energy Progress [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		243
Duke Energy Progress [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		553
Duke Energy Progress [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1
Duke Energy Progress [Member] | Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	308
Derivative assets	1	1
Total assets	766	788
Derivative liabilities	(7)	(12)
Net assets (liabilities)	759	776
Duke Energy Florida [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	593	616
Net assets (liabilities)	593	616
Duke Energy Florida [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Total assets	173	172
Derivative liabilities	(7)	(12)
Net assets (liabilities)	166	160
Duke Energy Florida [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	423
Available-for-sale Securities, Debt Securities	295
Duke Energy Florida [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	423
Available-for-sale Securities, Debt Securities	170
Duke Energy Florida [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	125
Duke Energy Florida [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	47
Duke Energy Florida [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	47
Duke Energy Florida [Member] | Equity Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		427
Duke Energy Florida [Member] | Equity Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		427
Duke Energy Florida [Member] | Debt Securities [Member] | Ndtf [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		312
Duke Energy Florida [Member] | Debt Securities [Member] | Ndtf [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		188
Duke Energy Florida [Member] | Debt Securities [Member] | Ndtf [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		124
Duke Energy Florida [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		48
Duke Energy Florida [Member] | Debt Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1
Duke Energy Florida [Member] | Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		47
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Derivative liabilities	(4)	(5)
Net assets (liabilities)	(3)	(4)
Duke Energy Ohio [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(4)	(5)
Net assets (liabilities)	(4)	(5)
Duke Energy Ohio [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	1
Net assets (liabilities)	1	1
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	96
Available-for-sale Securities, Debt Securities	31
Derivative assets	7	27
Total assets	134	155
Net assets (liabilities)	134	155
Duke Energy Indiana [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	0
Total assets	96	97
Derivative liabilities	0
Net assets (liabilities)	96	97
Duke Energy Indiana [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total assets	31	31
Net assets (liabilities)	31	31
Duke Energy Indiana [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	7	27
Total assets	7	27
Net assets (liabilities)	7	27
Duke Energy Indiana [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	96
Available-for-sale Securities, Debt Securities	31
Duke Energy Indiana [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Equity Securities, FV-NI	96
Duke Energy Indiana [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Available-for-sale Securities, Debt Securities	31
Duke Energy Indiana [Member] | Equity Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		97
Duke Energy Indiana [Member] | Equity Securities [Member] | Other Classification [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		97
Duke Energy Indiana [Member] | Debt Securities [Member] | Other Classification [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		31
Duke Energy Indiana [Member] | Debt Securities [Member] | Other Classification [Member] | Level 2 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		31
Piedmont Natural Gas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	2
Total assets		3
Derivative liabilities	(132)	(142)
Net assets (liabilities)	(131)	(139)
Piedmont Natural Gas [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative assets	1	2
Total assets		3
Net assets (liabilities)	1	3
Piedmont Natural Gas [Member] | Level 3 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative liabilities	(132)	(142)
Net assets (liabilities)	$ (132)	(142)
Piedmont Natural Gas [Member] | Debt Securities [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		1
Piedmont Natural Gas [Member] | Debt Securities [Member] | Level 1 [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments, Fair Value Disclosure		$ 1

XML

Fair Value Measurements (Reconciliation of Assets and Liabilities Measured At Fair Value On A Recurring Basis Using Unobservable Inputs) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair Value Measurement Transfers Between Activity Levels	$ 0	$ 0
Derivatives (net)
Beginning balance	(114,000,000)	(166,000,000)
Settlements	(14,000,000)	(9,000,000)
Total gains (losses) included on the Condensed Consolidated Balance Sheet	4,000,000	40,000,000
Ending balance	(124,000,000)	(135,000,000)
Investments and Derivatives, Net
Beginning balance	(114,000,000)	(161,000,000)
Settlements	(14,000,000)	(9,000,000)
Total gains (losses) included on the Condensed Consolidated Balance Sheet	4,000,000	40,000,000
Ending balance	(124,000,000)	(130,000,000)
Investments [Member]
Investments
Beginning balance		5,000,000
Ending balance		5,000,000
Duke Energy Ohio [Member]
Derivatives (net)
Beginning balance	1,000,000	5,000,000
Settlements	0	(1,000,000)
Total gains (losses) included on the Condensed Consolidated Balance Sheet	0	(3,000,000)
Ending balance	1,000,000	1,000,000
Duke Energy Indiana [Member]
Derivatives (net)
Beginning balance	27,000,000	16,000,000
Settlements	(14,000,000)	(7,000,000)
Total gains (losses) included on the Condensed Consolidated Balance Sheet	(6,000,000)	0
Ending balance	7,000,000	9,000,000
Piedmont Natural Gas [Member]
Derivatives (net)
Beginning balance	(142,000,000)	(187,000,000)
Total gains (losses) and settlements	10,000,000	42,000,000
Ending balance	$ (132,000,000)	$ (145,000,000)

XML

Fair Value Measurements (Quantitative Level 3 Fair Value Disclosure - Assets) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) $ / MWh	Mar. 31, 2017 USD ($) $ / MWh	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net derivative asset (liability)	$ (124)	$ (135)	$ (114)	$ (166)
Duke Energy Ohio [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net derivative asset (liability)	1	$ 1	1	5
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net derivative asset (liability)	$ 1		1
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input Price Per Unit | $ / MWh		0.07
Duke Energy Ohio [Member] | Financial Transmission Rights [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input Price Per Unit | $ / MWh	2.88	1.41
Duke Energy Indiana [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net derivative asset (liability)	$ 7	$ 9	27	$ 16
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Net derivative asset (liability)	$ 7		$ 27
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Minimum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input Price Per Unit | $ / MWh	(5.09)	(0.77)
Duke Energy Indiana [Member] | Financial Transmission Rights [Member] | Maximum [Member] | Market Approach Valuation Technique [Member]
Fair Value Inputs, Assets, Quantitative Information [Line Items]
Fair Value Input Price Per Unit | $ / MWh	7.58	7.44

XML

Fair Value Measurements (Quantitative Level 3 Fair Value Disclosure - Liabilities) (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) $ / MMBTU	Mar. 31, 2017 USD ($) $ / MMBTU	Dec. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Net derivative asset (liability)	$ (124)	$ (135)	$ (114)	$ (166)
Piedmont Natural Gas [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Net derivative asset (liability)	(132)	$ (145)	(142)	$ (187)
Derivative Financial Instruments, Liabilities [Member] | Discounted Cash Flow [Member] | Piedmont Natural Gas [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Net derivative asset (liability)	$ (132)		$ (142)
Derivative Financial Instruments, Liabilities [Member] | Minimum [Member] | Discounted Cash Flow [Member] | Piedmont Natural Gas [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Input Price Per Unit | $ / MMBTU	2.15	2.10
Derivative Financial Instruments, Liabilities [Member] | Maximum [Member] | Discounted Cash Flow [Member] | Piedmont Natural Gas [Member]
Fair Value Inputs, Liabilities, Quantitative Information [Line Items]
Fair Value Input Price Per Unit | $ / MMBTU	3.65	2.88

XML

Fair Value Measurements (Additional Fair Value Disclosure) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	$ 52,981	$ 52,279
Long-term debt, fair value	54,383	55,331
Duke Energy Carolinas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	10,694	10,103
Long-term debt, fair value	11,556	11,372
Progress Energy [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	17,757	17,837
Long-term debt, fair value	19,270	20,000
Duke Energy Progress [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	7,357	7,357
Long-term debt, fair value	7,687	7,992
Duke Energy Florida [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	7,015	7,095
Long-term debt, fair value	7,632	7,953
Duke Energy Ohio [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	2,067	2,067
Long-term debt, fair value	2,217	2,249
Duke Energy Indiana [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	3,782	3,783
Long-term debt, fair value	4,322	4,464
Piedmont Natural Gas [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term debt, book value	2,037	2,037
Long-term debt, fair value	$ 2,209	$ 2,209

XML

Variable Interest Entities (Narrative) (Details) - USD ($)	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2016
Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Financial or Other Support, Amount	$ 0	$ 0
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Percent of proceeds received as cash	75.00%
Percent of proceeds received as subordinated note	25.00%
Minimum equity balance required by Cinergy Receivables	$ 3,000,000
Pioneer Transmission [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	50.00%
OVEC [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest	9.00%
Duke Energy Ohio [Member] | Cinergy Receivables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Fixed interest rate added to LIBOR to compute variable rate	1.00%
Duke Energy Indiana [Member] | Cinergy Receivables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Fixed interest rate added to LIBOR to compute variable rate	1.00%

XML

Variable Interest Entities (Schedule of Accounts Receivable Securitizations) (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Apr. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entities [Line Items]
Long-Term Debt		$ 49,030	$ 49,035
Duke Energy Carolinas [Member]
Variable Interest Entities [Line Items]
Long-Term Debt		9,589	8,598
Duke Energy Progress [Member]
Variable Interest Entities [Line Items]
Long-Term Debt		6,604	7,204
Duke Energy Florida [Member]
Variable Interest Entities [Line Items]
Long-Term Debt		$ 6,247	6,327
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date		Dec. 01, 2020
Facility size		$ 325
Long-Term Debt		325	325
Accounts Receivable from Securitization		$ 504	545
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date		Dec. 01, 2020
Facility size		$ 450
Long-Term Debt		450	450
Accounts Receivable from Securitization		$ 634	640
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date		Feb. 01, 2021
Facility size		$ 300
Long-Term Debt		300	300
Accounts Receivable from Securitization		$ 497	459
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date		Apr. 01, 2019
Facility size		$ 225
Long-Term Debt		225	225
Accounts Receivable from Securitization		$ 313	$ 317
Subsequent Event [Member] | DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Line of Credit Facility, Expiration Date	Apr. 01, 2021

XML

Variable Interest Entities (Schedule of Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	$ 1,544	$ 1,437
Other, current assets	422	634
Regulatory assets, noncurrent	12,218	12,442
Property, plant and equipment, cost	129,281	127,507
Other noncurrent assets	3,062	2,960
Accumulated depreciation and amortization	(42,307)	(41,537)
Current Liabilities: Other	1,542	1,865
Current maturities of long-term debt	3,951	3,244
Long-Term Debt	49,030	49,035
Deferred income taxes	6,855	6,621
Noncurrent Liabilities: Other	1,538	1,581
Duke Energy Carolinas [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	331	299
Other, current assets	42	19
Regulatory assets, noncurrent	2,825	2,853
Property, plant and equipment, cost	43,562	42,939
Other noncurrent assets	1,023	979
Accumulated depreciation and amortization	(15,404)	(15,063)
Current Liabilities: Other	369	486
Current maturities of long-term debt	805	1,205
Long-Term Debt	9,589	8,598
Deferred income taxes	3,493	3,413
Noncurrent Liabilities: Other	532	566
Duke Energy Progress [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	476	352
Other, current assets	55	97
Regulatory assets, noncurrent	3,480	3,507
Property, plant and equipment, cost	29,866	29,583
Other noncurrent assets	641	599
Accumulated depreciation and amortization	(11,012)	(10,903)
Current Liabilities: Other	324	376
Current maturities of long-term debt	603	3
Long-Term Debt	6,604	7,204
Deferred income taxes	1,932	1,883
Noncurrent Liabilities: Other	46	45
Duke Energy Florida [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Regulatory assets, current	393	389
Other, current assets	40	86
Regulatory assets, noncurrent	2,391	2,503
Property, plant and equipment, cost	18,040	17,730
Other noncurrent assets	301	284
Accumulated depreciation and amortization	(5,042)	(4,947)
Current Liabilities: Other	299	334
Current maturities of long-term debt	768	768
Long-Term Debt	6,247	6,327
Deferred income taxes	1,812	1,761
Noncurrent Liabilities: Other	110	108
DEFPF [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	4	4
Regulatory assets, current	51	51
Other, current assets	13	40
Regulatory assets, noncurrent	1,082	1,091
Current Liabilities: Other	3	10
Current maturities of long-term debt	53	53
Long-Term Debt	1,136	1,164
DERF [Member] | Duke Energy Carolinas [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	634	640
Long-Term Debt	450	450
DEPR [Member] | Duke Energy Progress [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	497	459
Long-Term Debt	300	300
DEFR [Member] | Duke Energy Florida [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	313	317
Long-Term Debt	225	225
Cinergy Receivables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Receivables of VIEs	504	545
Long-Term Debt	325	325
Commercial Renewables [Member] | Variable Interest Entity, Primary Beneficiary [Member]
Variable Interest Entity, Consolidated, Carrying Amount, Assets and Liabilities, Net [Abstract]
Other, current assets	217	174
Property, plant and equipment, cost	4,017	3,923
Other noncurrent assets	227	50
Accumulated depreciation and amortization	(626)	(591)
Current maturities of long-term debt	171	170
Long-Term Debt	1,700	1,700
Deferred income taxes		(148)
Noncurrent Liabilities: Other	$ 236	$ 241

XML

Variable Interest Entities (Schedule of Non-Consolidated VIEs) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	$ 1,189	$ 1,175
Other noncurrent assets	3,062	2,960
Taxes accrued	422	551
Current Liabilities: Other	1,542	1,865
Deferred income taxes	6,855	6,621
Noncurrent Liabilities: Other	1,538	1,581
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	951	919
Other noncurrent assets	17	17
Total assets	968	936
Taxes accrued	(29)	(29)
Current Liabilities: Other	3	4
Deferred income taxes	32	42
Noncurrent Liabilities: Other	20	12
Total liabilities	26	29
Net assets	942	907
Pipeline Investments [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	723	697
Other noncurrent assets	17	17
Total assets	740	714
Taxes accrued	(29)	(29)
Deferred income taxes	32	42
Noncurrent Liabilities: Other	8
Total liabilities	11	13
Net assets	729	701
Commercial Renewables [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	183	180
Total assets	183	180
Net assets	183	180
Other VIEs [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Investments in equity method unconsolidated affiliates	45	42
Total assets	45	42
Current Liabilities: Other	3	4
Noncurrent Liabilities: Other	12	12
Total liabilities	15	16
Net assets	30	26
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	77	133
Other noncurrent assets	48	21
Taxes accrued	145	190
Current Liabilities: Other	66	71
Deferred income taxes	766	781
Noncurrent Liabilities: Other	105	108
Duke Energy Ohio [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	65	87
Total assets	65	87
Net assets	65	87
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	99	125
Other noncurrent assets	234	189
Taxes accrued	94	95
Current Liabilities: Other	83	104
Deferred income taxes	941	925
Noncurrent Liabilities: Other	28	18
Duke Energy Indiana [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Receivables from affiliated companies	86	106
Total assets	86	106
Net assets	$ 86	$ 106

XML

Variable Interest Entities (Pipeline Investments) (Details) - USD ($) $ in Millions		3 Months Ended
	Apr. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
Variable Interest Entities [Line Items]
Investments in Joint Ventures		$ 1,189	$ 1,175
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities		26	29
Investments in Joint Ventures		$ 951	919
Variable Interest Entity, Not Primary Beneficiary [Member] | Atlantic Coast Pipeline [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest		47.00%
Equity Method Investment Line Of Credit Facility Maximum Borrowing Capacity			3,400
Investments in Joint Ventures		$ 474	397
Variable Interest Entity, Not Primary Beneficiary [Member] | Atlantic Coast Pipeline [Member] | Revolving Credit Facility [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Entity Maximum Loss Exposure Percent		47.00%
Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities		$ 346
Variable Interest Entity, Not Primary Beneficiary [Member] | Sabal Trail Transmission Pipeline [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity Ownership Interest		7.50%
Investments in Joint Ventures		$ 223	219
Variable Interest Entity, Not Primary Beneficiary [Member] | Constitution Pipeline [Member]
Variable Interest Entities [Line Items]
Equity Method Investment, Other than Temporary Impairment		$ 55
Variable Interest Entity Ownership Interest		24.00%
Investments in Joint Ventures		$ 26	81
Variable Interest Entity, Not Primary Beneficiary [Member] | Pipeline Investments [Member]
Variable Interest Entities [Line Items]
Variable Interest Entity, Nonconsolidated, Carrying Amount, Liabilities		11	13
Investments in Joint Ventures		723	697
Piedmont Natural Gas [Member]
Variable Interest Entities [Line Items]
Investments in Joint Ventures		$ 62	$ 61
Subsequent Event [Member] | Variable Interest Entity, Not Primary Beneficiary [Member] | Sabal Trail Transmission Pipeline [Member]
Variable Interest Entities [Line Items]
Equity Method Investment Long Term Debt	$ 1,500
Proceeds from Equity Method Investment, Distribution, Return of Capital	$ 112

XML

Variable Interest Entities (Fair Value Assumptions)(Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - Cinergy Receivables [Member]	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Anticipated credit loss ratio	0.50%	0.50%
Discount rate	2.60%	2.10%
Receivable turnover rate	13.60%	13.50%
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Anticipated credit loss ratio	0.30%	0.30%
Discount rate	2.60%	2.10%
Receivable turnover rate	10.80%	10.70%

XML

Variable Interest Entities (Receivables Sold)(Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - Cinergy Receivables [Member] - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables sold	$ 249	$ 273
Less: Retained interests	65	87
Net receivables sold	184	186
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables sold	297	312
Less: Retained interests	86	106
Net receivables sold	$ 211	$ 206

XML

Variable Interest Entities (Sales and Cash Flows)(Details) - Variable Interest Entity, Not Primary Beneficiary [Member] - Cinergy Receivables [Member] - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Duke Energy Ohio [Member]
Variable Interest Entities [Line Items]
Receivables sold	$ 567	$ 533
Loss recognized on sale	3	2
Cash proceeds from receivables sold	585	559
Return received on retained interests	2	1
Duke Energy Indiana [Member]
Variable Interest Entities [Line Items]
Receivables sold	694	664
Loss recognized on sale	3	3
Cash proceeds from receivables sold	711	693
Return received on retained interests	$ 2	$ 2

XML

Revenue (Details)	3 Months Ended
	Mar. 31, 2018 USD ($)
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 5,928,000,000
Difference between Revenue Guidance in Effect before and after Topic 606 [Member] | Accounting Standards Update 2014-09 [Member]
Revenue, Initial Application Period Cumulative Effect Transition [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 0

XML

Revenue Remaining Performance Obligations (Details) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($)
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 69
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 112
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 121
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 80
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 82
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 81
Progress Energy [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	545
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 18
Duke Energy Progress [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	61
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 62
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 103
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 112
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 71
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 73
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 63
Duke Energy Florida [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	484
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 6
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 9
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 10
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 5
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 0
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 0
Duke Energy Indiana [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	30
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 55
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	9 months
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 72
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 70
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 65
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 64
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	1 year
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 482
Piedmont Natural Gas [Member] | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: (nil)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation	$ 808

XML

Revenue Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 5,928
Revenue from Sources other than Contracts with Customers	207
Operating revenues	6,135	$ 5,729
Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	5,161
Operating revenues	5,315	4,939
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,350
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,375
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	664
Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	633
Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	139
Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	717
Operating revenues	702	648
Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	55
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	413
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	48
Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	201
Commercial Renewables [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	33
Operating revenues	101	128
Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	17
Duke Energy Carolinas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,694
Revenue from Sources other than Contracts with Customers	69
Operating revenues	1,763	1,716
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,694
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	781
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	472
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	255
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	119
Duke Energy Carolinas [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	67
Progress Energy [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,526
Revenue from Sources other than Contracts with Customers	50
Operating revenues	2,576	2,179
Progress Energy [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	2,526
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,112
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	631
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	208
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	446
Progress Energy [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	129
Duke Energy Progress [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,442
Revenue from Sources other than Contracts with Customers	18
Operating revenues	1,460	1,219
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,442
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	516
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	299
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	145
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	397
Duke Energy Progress [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	85
Duke Energy Florida [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,083
Revenue from Sources other than Contracts with Customers	32
Operating revenues	1,115	959
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	1,083
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	595
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	333
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	62
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	50
Duke Energy Florida [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	43
Duke Energy Ohio [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	507
Revenue from Sources other than Contracts with Customers	17
Operating revenues	524	518
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	320
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	180
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	96
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	30
Duke Energy Ohio [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	14
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	173
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	6
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	111
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	7
Duke Energy Ohio [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	49
Duke Energy Ohio [Member] | Other [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	14
Duke Energy Indiana [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	714
Revenue from Sources other than Contracts with Customers	17
Operating revenues	731	758
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	714
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	278
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | General [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	178
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	173
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Electricity, US Regulated [Member] | Wholesale [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	68
Duke Energy Indiana [Member] | Electric Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	17
Piedmont Natural Gas [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	557
Revenue from Sources other than Contracts with Customers	(4)
Operating revenues	553	$ 500
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	557
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Other Revenues [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	49
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Residential [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	302
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Industrial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	41
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Commercial [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	152
Piedmont Natural Gas [Member] | Gas Utilities and Infrastructure [Member] | Natural Gas, US Regulated [Member] | Power Generation [Member]
Disaggregation of Revenue [Line Items]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 13

XML

Revenue Unbilled Revenues (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	$ 823	$ 944
Duke Energy Carolinas [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	310	342
Progress Energy [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	237	228
Duke Energy Progress [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	167	143
Duke Energy Florida [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	70	85
Duke Energy Ohio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	2	4
Duke Energy Indiana [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	24	21
Piedmont Natural Gas [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	45	86
Cinergy Receivables [Member] | Duke Energy Ohio [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	67	104
Cinergy Receivables [Member] | Duke Energy Indiana [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Unbilled receivables	$ 108	$ 132

XML

Common Stock (Earnings Per Share Data)(Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Earnings Per Share [Abstract]
Income from continuing operations attributable to Duke Energy common stockholders excluding impact of participating securities	$ 619	$ 715
Average shares, basic	701	700
Average shares, diluted	701	700
EPS, basic (usd per share)	$ 0.88	$ 1.02
EPS, diluted (usd per share)	$ 0.88	$ 1.02
Number of stock options and performance and unvested stock awards excluded from the dilutive securities calculation	2	2
Dividends declared per share (usd per share)	$ 0.89	$ 0.855

XML

Common Stock (Equity Securities Offering) (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Billions		1 Months Ended
	Feb. 20, 2018	Mar. 31, 2018
Forward Contract Indexed to Issuer's Equity [Line Items]
Maximum Value Of Shares To Be Issued Under ATM Program	$ 1
Shares offered		21.3
Settlement Alternatives, Shares		21.3
Forward Contract Indexed to Issuer's Equity, Forward Rate Per Share		$ 74.07
Forward Contract Indexed to Issuer's Equity, Shares		0.9

XML

Stock-Based Compensation (Schedule of Stock-Based Compensation Expense) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation cost	$ 17	$ 15
Tax benefit associated with stock-based compensation expense	4	5
Stock-based compensation costs capitalized	1	1
Restricted Stock Units Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation cost	10	8
Performance Awards [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Pretax stock-based compensation cost	$ 7	$ 7

XML

Employee Benefit Plans (Plan Contributions) (Details) - Qualified Pension Plan [Member] - USD ($)	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	$ 148,000,000
Contributions by Employer	141,000,000	$ 0
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	7,000,000
Duke Energy Carolinas [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	46,000,000
Contributions by Employer	46,000,000
Progress Energy [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	45,000,000
Contributions by Employer	45,000,000
Duke Energy Progress [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	25,000,000
Contributions by Employer	25,000,000
Duke Energy Florida [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	20,000,000
Contributions by Employer	20,000,000
Duke Energy Indiana [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	8,000,000
Contributions by Employer	8,000,000
Piedmont Natural Gas [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Current Fiscal Year	7,000,000
Defined Benefit Plan, Expected Future Employer Contributions, Remainder of Fiscal Year	$ 7,000,000

XML

Employee Benefit Plans (Components of Net Periodic Pension Costs) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Qualified Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 45	$ 40
Interest cost on projected benefit obligation	75	82
Expected return on plan assets	(140)	(136)
Amortization of actuarial loss (gain)	33	36
Amortization of prior service credit	(8)	(6)
Other		2
Net periodic costs	5	18
Qualified Pension Plan [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	15	12
Interest cost on projected benefit obligation	18	20
Expected return on plan assets	(37)	(35)
Amortization of actuarial loss (gain)	7	8
Amortization of prior service credit	(2)	(2)
Net periodic costs	1	3
Qualified Pension Plan [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	13	12
Interest cost on projected benefit obligation	24	25
Expected return on plan assets	(45)	(43)
Amortization of actuarial loss (gain)	11	14
Amortization of prior service credit	(1)	(1)
Other		1
Net periodic costs	2	8
Qualified Pension Plan [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	7	6
Interest cost on projected benefit obligation	11	12
Expected return on plan assets	(21)	(21)
Amortization of actuarial loss (gain)	5	6
Net periodic costs	2	3
Qualified Pension Plan [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	5	5
Interest cost on projected benefit obligation	13	13
Expected return on plan assets	(23)	(21)
Amortization of actuarial loss (gain)	6	7
Net periodic costs	1	4
Qualified Pension Plan [Member] | Duke Energy Ohio [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1
Interest cost on projected benefit obligation	5	5
Expected return on plan assets	(7)	(7)
Amortization of actuarial loss (gain)	1	1
Qualified Pension Plan [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	2
Interest cost on projected benefit obligation	6	7
Expected return on plan assets	(10)	(11)
Amortization of actuarial loss (gain)	2	3
Net periodic costs		1
Qualified Pension Plan [Member] | Piedmont Natural Gas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	2	3
Interest cost on projected benefit obligation	3	3
Expected return on plan assets	(6)	(6)
Amortization of actuarial loss (gain)	3	3
Amortization of prior service credit	(3)	(1)
Net periodic costs	(1)	2
Other Post-Retirement Benefit Plans [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	1	1
Interest cost on projected benefit obligation	7	9
Expected return on plan assets	(2)	(3)
Amortization of actuarial loss (gain)	1	2
Amortization of prior service credit	(5)	(29)
Net periodic costs	2	(20)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Carolinas [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost on projected benefit obligation	2	2
Expected return on plan assets	(2)	(2)
Amortization of actuarial loss (gain)		(1)
Amortization of prior service credit	(1)	(2)
Net periodic costs	(1)	(3)
Other Post-Retirement Benefit Plans [Member] | Progress Energy [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost on projected benefit obligation	4	4
Amortization of actuarial loss (gain)		5
Amortization of prior service credit	(2)	(21)
Net periodic costs	2	(12)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Progress [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost on projected benefit obligation	1	2
Amortization of actuarial loss (gain)		3
Amortization of prior service credit		(14)
Net periodic costs	1	(9)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Florida [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost on projected benefit obligation	1	2
Amortization of actuarial loss (gain)		2
Amortization of prior service credit	(1)	(8)
Net periodic costs		$ (4)
Other Post-Retirement Benefit Plans [Member] | Duke Energy Indiana [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Interest cost on projected benefit obligation	1
Amortization of actuarial loss (gain)	1
Net periodic costs	$ 2

XML

Employee Benefit Plans (Employee Savings Plans) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	$ 70	$ 65
Duke Energy Carolinas [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	23	22
Progress Energy [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	19	18
Duke Energy Progress [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	13	13
Duke Energy Florida [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	6	5
Duke Energy Ohio [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	1	1
Duke Energy Indiana [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	3	3
Piedmont Natural Gas [Member]
Defined Contribution Plan Disclosure [Line Items]
Employer contributions	$ 4	$ 2

XML

Income Taxes (Effective Tax Rates) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Income Tax Disclosure [Line Items]
Tax Cuts and Jobs Act of 2017 Incomplete Accounting Provisional Income Tax Expense Benefit	$ 76
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	22.50%	32.40%
Duke Energy Carolinas [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	22.00%	35.40%
Progress Energy [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	13.20%	34.10%
Duke Energy Progress [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	14.10%	34.10%
Duke Energy Florida [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	16.30%	36.60%
Duke Energy Ohio [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	32.40%	35.40%
Duke Energy Indiana [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	25.90%	39.30%
Piedmont Natural Gas [Member]
Reconciliation of Income Tax Expense at the U.S. Federal Statutory Tax Rate to the Actual Tax Expense from Continuing Operations [Abstract]
Effective tax rate	24.10%	37.90%