10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 10-Q

(Mark One)

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

For the quarterly period ended March 31, 2023

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: 001-03140

Northern States Power Company

(Exact Name of Registrant as Specified in its Charter)

Wisconsin			39-0508315
(State or Other Jurisdiction of Incorporation or Organization)			(I.R.S Employer Identification No.)
1414 West Hamilton Avenue	Eau Claire	Wisconsin	54701
(Address of Principal Executive Offices)			(Zip Code)

(715)	737-2625
(Registrant’s Telephone Number, Including Area Code)

Securities registered pursuant to Section 12(b) of the Act:

Title of each class	Trading Symbol(s)	Name of each exchange on which registered
N/A	N/A	N/A

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. ☒ Yes  ☐ No

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted 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 such files). ☒ Yes  ☐ 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.

Large accelerated filer	☐	Accelerated filer	☐
Non-accelerated filer	☒	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). ☐ Yes ☒ No

Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date.

Class	Outstanding at April 27, 2023
Common Stock, $100 par value	933,000 shares

Northern States Power Company meets the conditions set forth in General Instructions H(1)(a) and (b) of Form 10-Q and is therefore filing this Form 10-Q with the reduced disclosure format specified in General Instruction H(2) to such Form 10-Q.

TABLE OF CONTENTS

PART I	FINANCIAL INFORMATION
Item 1 —	Financial Statements (unaudited)	4
	Consolidated Statements of Income	4
	Consolidated Statements of Cash Flows	5
	Consolidated Balance Sheets	6
	Consolidated Statements of Common Stockholder's Equity	7
	Notes to Consolidated Financial Statements	8
Item 2 —	Management’s Discussion and Analysis of Financial Condition and Results of Operations	11
Item 4 —	Controls and Procedures	13
PART II	OTHER INFORMATION
Item 1 —	Legal Proceedings	14
Item 1A —	Risk Factors	14
Item 6 —	Exhibits	14
SIGNATURES		15

This Form 10-Q is filed by NSP-Wisconsin. NSP-Wisconsin is a wholly owned subsidiary of Xcel Energy Inc. Additional information on Xcel Energy is available in various filings with the SEC. This report should be read in its entirety.

Definitions of Abbreviations

Xcel Energy Inc.’s Subsidiaries and Affiliates (current and former)
e prime	e prime inc.
NSP-Minnesota	Northern States Power Company, a Minnesota corporation
NSP System	The electric production and transmission system of NSP-Minnesota and NSP-Wisconsin operated on an integrated basis and managed by NSP-Minnesota
NSP-Wisconsin	Northern States Power Company, a Wisconsin corporation
PSCo	Public Service Company of Colorado
SPS	Southwestern Public Service Company
Utility subsidiaries	NSP-Minnesota, NSP-Wisconsin, PSCo and SPS
Xcel Energy	Xcel Energy Inc. and its subsidiaries

Federal and State Regulatory Agencies
D.C. Circuit	United States Court of Appeals for the District of Columbia Circuit
EPA	United States Environmental Protection Agency
FERC	Federal Energy Regulatory Commission
PSCW	Public Service Commission of Wisconsin
SEC	Securities and Exchange Commission

Other
C&I	Commercial and Industrial
CEO	Chief executive officer
CERCLA	Comprehensive Environmental Response, Compensation, and Liability Act
CFO	Chief financial officer
CSPV	Crystalline Silicon Photovoltaic
GAAP	United States generally accepted accounting principles
IRA	Inflation Reduction Act
MGP	Manufactured gas plant
MISO	Midcontinent Independent System Operator, Inc.
NOx	Nitrogen Oxides
PFAS	Per- and PolyFluoroAlkyl Substances
O&M	Operating and maintenance
ROE	Return on equity
TOs	Transmission owners
Measurements
MW	Megawatts

Forward-Looking Statements

Except for the historical statements contained in this report, the matters discussed herein are forward-looking statements that are subject to certain risks, uncertainties and assumptions. Such forward-looking statements, including those relating to future sales, future expenses, future tax rates, future operating performance, estimated base capital expenditures and financing plans, projected capital additions and forecasted annual revenue requirements with respect to rider filings, expected rate increases to customers, expectations and intentions regarding regulatory proceedings, and expected impact on our results of operations, financial condition and cash flows of resettlement calculations and credit losses relating to certain energy transactions, as well as assumptions and other statements are intended to be identified in this document by the words “anticipate,” “believe,” “could,” “estimate,” “expect,” “intend,” “may,” “objective,” “outlook,” “plan,” “project,” “possible,” “potential,” “should,” “will,” “would” and similar expressions. Actual results may vary materially. Forward-looking statements speak only as of the date they are made, and we expressly disclaim any obligation to update any forward-looking information. The following factors, in addition to those discussed in NSP-Wisconsin's Annual Report on Form 10-K for the fiscal year ended Dec. 31, 2022, and subsequent filings with the SEC, could cause actual results to differ materially from management expectations as suggested by such forward-looking information: operational safety; successful long-term operational planning; commodity risks associated with energy markets and production; rising energy prices and fuel costs; qualified employee work force and third-party contractor factors; violations of our Codes of Conduct; our ability to recover costs; changes in regulation; reductions in our credit ratings and the cost of maintaining certain contractual relationships; general economic conditions, including recessionary conditions, inflation rates, monetary fluctuations, supply chain constraints and their impact on capital expenditures and/or the ability of NSP-Wisconsin to obtain financing on favorable terms; availability or cost of capital; our customers’ and counterparties’ ability to pay their debts to us; assumptions and costs relating to funding our employee benefit plans and health care benefits; tax laws; uncertainty regarding epidemics, the duration and magnitude of business restrictions including shutdowns (domestically and globally), the potential impact on the workforce, including shortages of employees or third-party contractors due to quarantine policies, vaccination requirements or government restrictions, impacts on the transportation of goods and the generalized impact on the economy; effects of geopolitical events, including war and acts of terrorism; cyber security threats and data security breaches; seasonal weather patterns; changes in environmental laws and regulations; climate change and other weather events; natural disaster and resource depletion, including compliance with any accompanying legislative and regulatory changes; costs of potential regulatory penalties; regulatory changes and/or limitations related to the use of natural gas as an energy source; challenging labor market conditions and our ability to attract and retain a qualified workforce; and our ability to execute on our strategies or achieve expectations related to environmental, social and governance matters including as a result of evolving legal, regulatory and other standards, processes, and assumptions, the pace of scientific and technological developments, increased costs, the availability of requisite financing, and changes in carbon markets.

PART I — FINANCIAL INFORMATION

ITEM 1 — FINANCIAL STATEMENTS

NSP-WISCONSIN AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED)

(amounts in millions)

	Three Months Ended March 31
	2023		2022
Operating revenues
Electric, non-affiliates	$	204	$	203
Electric, affiliates	50		47
Natural gas	77		78
Total operating revenues	331		328
Operating expenses
Electric fuel and purchased power, non-affiliates	4		4
Purchased power, affiliates	103		108
Cost of natural gas sold and transported	46		45
Operating and maintenance expenses	58		53
Conservation program expenses	3		3
Depreciation and amortization	41		38
Taxes (other than income taxes)	8		8
Total operating expenses	263		259
Operating income	68		69
Allowance for funds used during construction — equity	2		2
Interest charges and financing costs
Interest charges	13		11
Allowance for funds used during construction — debt	(1)		(1)
Total interest charges and financing costs	12		10
Income before income taxes	58		61
Income tax expense	13		14
Net income	$	45	$	47

See Notes to Consolidated Financial Statements

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NSP-WISCONSIN AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED)

(amounts in millions)

	Three Months Ended March 31
	2023		2022
Operating activities
Net income	$	45	$	47
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	42		39
Deferred income taxes	(2)		(1)
Allowance for equity funds used during construction	(2)		(2)
Provision for bad debts	2		2
Changes in operating assets and liabilities:
Accounts receivable	(16)		(17)
Accrued unbilled revenues	20		18
Inventories	15		4
Other current assets	13		5
Accounts payable	(10)		(8)
Net regulatory assets and liabilities	17		4
Other current liabilities	—		15
Pension and other employee benefit obligations	(3)		(1)
Other, net	1		3
Net cash provided by operating activities	122		108
Investing activities
Capital/construction expenditures	(101)		(87)
Net cash used in investing activities	(101)		(87)
Financing activities
Repayments of short-term borrowings, net	(35)		(83)
Borrowings under utility money pool arrangement	—		235
Repayments under utility money pool arrangement	—		(187)
Capital contributions from parent	36		31
Dividends paid to parent	(23)		(27)
Other, net	—		1
Net cash used in financing activities	(22)		(30)
Net change in cash, cash equivalents and restricted cash	(1)		(9)
Cash, cash equivalents and restricted cash at beginning of period	2		11
Cash, cash equivalents and restricted cash at end of period	$	1	$	2
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	$	(13)	$	(10)
Cash paid for income taxes, net	(4)		—
Supplemental disclosure of non-cash investing and financing transactions:
Accrued property, plant and equipment additions	$	33	$	17
Inventory transfers to property, plant and equipment	2		1
Allowance for equity funds used during construction	2		2

See Notes to Consolidated Financial Statements

5

NSP-WISCONSIN AND SUBSIDIARIES

CONSOLIDATED BALANCE SHEETS (UNAUDITED)

(amounts in millions, except share and per share data)

	March 31, 2023		Dec. 31, 2022
Assets
Current assets
Cash and cash equivalents	$	1	$	2
Accounts receivable, net	92		84
Accrued unbilled revenues	53		74
Other receivables	14		19
Inventories	23		39
Regulatory assets	37		44
Prepaid taxes	21		27
Prepayments and other	8		11
Total current assets	249		300
Property, plant and equipment, net	2,971		2,914
Other assets
Regulatory assets	189		193
Other	3		3
Total other assets	192		196
Total assets	$	3,412	$	3,410
Liabilities and Equity
Current liabilities
Short-term debt	12		47
Accounts payable	58		92
Accounts payable to affiliates	26		19
Dividends payable to parent	24		23
Regulatory liabilities	26		21
Taxes accrued	22		13
Accrued interest	10		12
Other	20		28
Total current liabilities	198		255
Deferred credits and other liabilities
Deferred income taxes	334		333
Deferred investment tax credits	5		5
Regulatory liabilities	393		383
Customer advances	23		23
Pension and employee benefit obligations	20		23
Other	42		43
Total deferred credits and other liabilities	817		810
Commitments and contingencies
Capitalization
Long-term debt	1,087		1,086
Common stock — 1,000,000 shares authorized of $100 par value; 933,000 shares outstanding at March 31, 2023 and Dec. 31, 2022, respectively	93		93
Additional paid in capital	791		761
Retained earnings	426		405
Total common stockholder's equity	1,310		1,259
Total liabilities and equity	$	3,412	$	3,410

See Notes to Consolidated Financial Statements

6

NSP-WISCONSIN AND SUBSIDIARIES

CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY (UNAUDITED)

(amounts in millions, except share data)

	Common Stock Issued					Retained Earnings		Total Common Stockholder's Equity
	Shares	Par Value		Additional Paid In Capital
Three Months Ended March 31, 2023 and 2022
Balance at Dec. 31, 2021	933,000	$	93	$	642	$	368	$	1,103
Net income						47		47
Common dividends declared to parent						(22)		(22)
Contribution of capital by parent				30				30
Balance at March 31, 2022	933,000	$	93	$	672	$	393	$	1,158
Balance at Dec. 31, 2022	933,000	$	93	$	761	$	405	$	1,259
Net income						45		45
Common dividends declared to parent						(24)		(24)
Contribution of capital by parent				30				30
Balance at March 31, 2023	933,000	$	93	$	791	$	426	$	1,310

See Notes to Consolidated Financial Statements

7

NSP-WISCONSIN AND SUBSIDIARIES

Notes to Consolidated Financial Statements (UNAUDITED)

In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments necessary to present fairly, in accordance with GAAP, the financial position of NSP-Wisconsin and its subsidiaries as of March 31, 2023 and Dec. 31, 2022; the results of NSP-Wisconsin's operations, including the components of net income, changes in stockholder's equity and comprehensive income for the three months ended March 31, 2023 and 2022; and NSP-Wisconsin's cash flows for the three months ended March 31, 2023 and 2022.

All adjustments are of a normal, recurring nature, except as otherwise disclosed. Management has also evaluated the impact of events occurring after March 31, 2023 up to the date of issuance of these consolidated financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. The Dec. 31, 2022 balance sheet information has been derived from the audited 2022 consolidated financial statements included in the NSP-Wisconsin Annual Report on Form 10-K for the year ended Dec. 31, 2022.

Notes to the consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP on an annual basis have been condensed or omitted pursuant to such rules and regulations. For further information, refer to the consolidated financial statements and notes thereto included in the NSP-Wisconsin Annual Report on Form 10-K for the year ended Dec. 31, 2022, filed with the SEC on Feb. 23, 2023. Due to the seasonality of NSP-Wisconsin’s electric and natural gas sales, interim results are not necessarily an appropriate base from which to project annual results.

1. Summary of Significant Accounting Policies

The significant accounting policies set forth in Note 1 to the consolidated financial statements in the NSP-Wisconsin Annual Report on Form 10-K for the year ended Dec. 31, 2022 appropriately represent, in all material respects, the current status of accounting policies and are incorporated herein by reference.

2. Accounting Pronouncements

As of March 31, 2023, there was no material impact from the recent adoption of new accounting pronouncements, nor expected material impact from recently issued accounting pronouncements yet to be adopted, on NSP-Wisconsin's consolidated financial statements.

3. Selected Balance Sheet Data

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Accounts receivable, net
Accounts receivable	$	101	$	93
Less allowance for bad debts	(9)		(9)
Accounts receivable, net	$	92	$	84

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Inventories
Materials and supplies	$	9	$	8
Fuel	11		11
Natural gas	3		20
Total inventories	$	23	$	39

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Property, plant and equipment, net
Electric plant	$	3,649	$	3,579
Natural gas plant	471		465
Common and other property	264		260
Construction work in progress	172		174
Total property, plant and equipment	4,556		4,478
Less accumulated depreciation	(1,585)		(1,564)
Property, plant and equipment, net	$	2,971	$	2,914

4. Borrowings and Other Financing Instruments

Short-Term Borrowings

NSP-Wisconsin meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility and the money pool.

Money Pool — Xcel Energy Inc. and its utility subsidiaries have established a money pool arrangement that allows for short-term investments in and borrowings between the utility subsidiaries. Xcel Energy Inc. may make investments in the utility subsidiaries at market-based interest rates; however, the money pool arrangement does not allow the utility subsidiaries to make investments in Xcel Energy Inc.

Money pool borrowings:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2023		Year Ended Dec. 31, 2022
Borrowing limit	$	150	$	150
Amount outstanding at period end	—		—
Average amount outstanding	—		25
Maximum amount outstanding	—		81
Weighted average interest rate, computed on a daily basis	N/A		1.10		%
Weighted average interest rate at period end	N/A		N/A

Commercial Paper — Commercial paper outstanding:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2023			Year Ended Dec. 31, 2022
Borrowing limit	$	150		$	150
Amount outstanding at period end	12			47
Average amount outstanding	48			18
Maximum amount outstanding	93			123
Weighted average interest rate, computed on a daily basis	4.71		%	1.03		%
Weighted average interest rate at period end	5.05			4.55

Letters of Credit — NSP-Wisconsin uses letters of credit, generally with terms of one year, to provide financial guarantees for certain obligations. At both March 31, 2023 and Dec. 31, 2022, there were no letters of credit outstanding under the credit facility.

Revolving Credit Facility — In order to issue its commercial paper, NSP-Wisconsin must have a revolving credit facility equal or greater than the commercial paper borrowing limit and cannot issue commercial paper exceeding available capacity under this credit facility. The credit facility provides short-term financing in the form of notes payable to banks, letters of credit and back-up support for commercial paper borrowings.

NSP-Wisconsin has the right to request an extension of the revolving credit facility termination date for an additional one-year period. All extension requests are subject to majority bank group approval.

8

As of March 31, 2023, NSP-Wisconsin had the following committed revolving credit facility available (in millions of dollars):

Credit Facility (a)		Outstanding (b)		Available
$	150	$	12	$	138

(a)Expires in September 2027.

(b)Includes outstanding commercial paper.

All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. NSP-Wisconsin had no direct advances on the credit facility outstanding at March 31, 2023 and Dec. 31, 2022.

Other Short-Term Borrowings — Clearwater Investments, Inc., a NSP-Wisconsin subsidiary, had an immaterial note payable to Xcel Energy Inc. as of March 31, 2023 and Dec. 31, 2022, respectively.

Long-Term Borrowings and Other Financing Instruments

On April 21, 2023, NSP-Wisconsin priced a private placement of $125 million of 5.30% first mortgage bonds due June 15, 2053. The closing of the sale of the bonds is subject to execution of a bond purchase agreement and customary closing conditions and is expected to occur in June 2023.

5. Revenues

Revenue is classified by the type of goods/services rendered and market/customer type. NSP-Wisconsin’s operating revenues consisted of the following:

	Three Months Ended March 31, 2023
(Millions of Dollars)	Electric		Natural Gas		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	82	$	41	$	123
C&I	120		34		154
Other	2		—		2
Total retail	204		75		279
Interchange	50		—		50
Other	(3)		1		(2)
Total revenue from contracts with customers	251		76		327
Alternative revenue and other	3		1		4
Total revenues	$	254	$	77	$	331

	Three Months Ended March 31, 2022
(Millions of Dollars)	Electric		Natural Gas		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	81	$	42	$	123
C&I	116		34		150
Other	2		—		2
Total retail	199		76		275
Interchange	47		—		47
Other	1		1		2
Total revenue from contracts with customers	247		77		324
Alternative revenue and other	3		1		4
Total revenues	$	250	$	78	$	328

6. Income Taxes

Reconciliation between the statutory rate and effective tax rate:

	Three Months Ended March 31
	2023		2022
Federal statutory rate	21.0	%	21.0	%
State tax (net of federal tax effect)	6.2		6.2
Decreases:
Plant regulatory differences (a)	(3.5)		(3.7)
Other (net)	(1.3)		(0.5)
Effective income tax rate	22.4	%	23.0	%

(a)Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

7. Fair Value of Financial Assets and Liabilities

Fair Value Measurements

Accounting guidance for fair value measurements and disclosures provides a hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value.

•Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. The types of assets and liabilities included in Level 1 are actively traded instruments with observable actual trading prices.

•Level 2 — Pricing inputs are other than actual trading prices in active markets, but are either directly or indirectly observable as of the reporting date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts or priced with models using highly observable inputs.

•Level 3 — Significant inputs to pricing have little or no observability as of the reporting date. The types of assets and liabilities included in Level 3 include those valued with models requiring significant judgment or estimation.

Specific valuation methods include:

Commodity Derivatives — Methods used to measure the fair value of commodity derivative forwards and options utilize forward prices and volatilities, as well as pricing adjustments for specific delivery locations, and are generally assigned a Level 2 classification. When contracts relate to inactive delivery locations or extend to periods beyond those readily observable on active exchanges, the significance of the use of less observable inputs on a valuation is evaluated, and may result in Level 3 classification.

Derivative Activities and Fair Value Measurements

NSP-Wisconsin enters into derivative instruments, including forward contracts, futures, swaps and options, to manage risk in connection with changes in utility commodity prices.

Commodity Derivatives — NSP-Wisconsin enters into derivative instruments to manage variability of future cash flows from changes in commodity prices in its electric and natural gas operations. This could include the purchase or sale of natural gas to generate electric energy and natural gas for resale.

As of March 31, 2023, NSP-Wisconsin had no commodity contracts designated as cash flow hedges.

9

Consideration of Credit Risk and Concentrations — NSP-Wisconsin continuously monitors the creditworthiness of counterparties to its interest rate derivatives and commodity derivative contracts prior to settlement, and assesses each counterparty’s ability to perform on the transactions set forth in the contracts. Impact of credit risk was immaterial to the fair value of unsettled commodity derivatives presented on the consolidated balance sheets.

Recurring Derivative Fair Value Measurements

Impact of derivative activity:

Changes in the fair value of natural gas commodity derivatives resulted in $1 million of net gains for the three months ended March 31, 2023, which were recognized as regulatory assets and liabilities. The classification as a regulatory asset or liability is based on commission approved regulatory recovery mechanisms. Immaterial net gains were recognized for the three months ended March 31, 2022.

During the three months ended March 31, 2023 and 2022, there were immaterial natural gas commodity derivatives settlement losses and gains.

During the three months ended March 31, 2023, $2 million of pre-tax losses were recognized during the period in income related to option premium amortization. During the three months ended March 31, 2022, similar activity was immaterial.

NSP-Wisconsin had no outstanding derivative assets or liabilities measured at fair value as of March 31, 2023. Derivative assets and liabilities measured at fair value on a recurring basis were as follows as of Dec. 31, 2022:

	Dec. 31, 2022
	Fair Value						Fair Value Total		Netting (a)		Total
(Millions of Dollars)	Level 1		Level 2		Level 3
Current derivative assets
Natural gas commodity (b)	$	—	$	2	$	—	$	2	$	—	$	2
Current derivative liabilities
Natural gas commodity (b)	$	—	$	1	$	—	$	1	$	—	$	1

(a)NSP-Wisconsin nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

(b)$2 million included in prepayments and other current assets and $1 million included in other current liabilities at Dec. 31, 2022 on the consolidated balance sheet.

Fair Value of Long-Term Debt

As of March 31, 2023, other financial instruments for which the carrying amount did not equal fair value:

	March 31, 2023				Dec. 31, 2022
(Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt, including current portion	$	1,087	$	1,006	$	1,086	$	980

Fair value of NSP-Wisconsin’s long-term debt is estimated based on recent trades and observable spreads from benchmark interest rates for similar securities. Fair value estimates are based on information available to management as of March 31, 2023 and Dec. 31, 2022 and given the observability of the inputs, fair values presented for long-term debt were assigned as Level 2.

8. Benefit Plans and Other Postretirement Benefits

Components of Net Periodic Benefit Cost

	Three Months Ended March 31
	2023		2022
(Millions of Dollars)	Pension Benefits
Service cost	$	1	$	1
Interest cost (a)	2		1
Expected return on plan assets (a)	(2)		(2)
Amortization of net loss (a)	—		1
Net benefit cost recognized for financial reporting	$	1	$	1

(a)The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.

In January 2023, contributions totaling $50 million were made across Xcel Energy’s pension plans, of which $4 million was attributable to NSP-Wisconsin. Xcel Energy does not expect additional pension contributions during 2023.

9. Commitments and Contingencies

Legal

NSP-Wisconsin is involved in various litigation matters in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. Management maintains accruals for losses probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including but not limited to when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories.

In such cases, there is considerable uncertainty regarding the timing or ultimate resolution, including a possible eventual loss. For current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, would have a material effect on NSP-Wisconsin’s consolidated financial statements. Legal fees are generally expensed as incurred.

Gas Trading Litigation — e prime is a wholly owned subsidiary of Xcel Energy. e prime was in the business of natural gas trading and marketing but has not engaged in natural gas trading or marketing activities since 2003. Multiple lawsuits involving multiple plaintiffs seeking monetary damages were commenced against e prime and its affiliates, including Xcel Energy, between 2003 and 2009 alleging fraud and anticompetitive activities in conspiring to restrain the trade of natural gas and manipulate natural gas prices. Cases were all consolidated in the U.S. District Court in Nevada.

10

One case remains active which includes a multi-district litigation matter consisting of a Wisconsin purported class (Arandell Corp.). The Court issued a ruling in June 2022 granting plaintiffs’ class certification. In April 2023, the Seventh Circuit Court of Appeals heard the defendants’ appeal challenging whether the district court properly assessed class certification. A decision relating to class certification is expected later this year. Xcel Energy considers the reasonably possible loss associated with this litigation to be immaterial.

Rate Matters

NSP-Wisconsin is involved in various regulatory proceedings arising in the ordinary course of business. Until resolution, typically in the form of a rate order, uncertainties may exist regarding the ultimate rate treatment for certain activities and transactions. Amounts have been recognized for probable and reasonably estimable losses that may result. Unless otherwise disclosed, any reasonably possible range of loss in excess of any recognized amount is not expected to have a material effect on the financial statements.

MISO ROE Complaints — In November 2013 and February 2015, customer groups filed two ROE complaints against MISO TOs, which includes NSP-Minnesota and NSP-Wisconsin. The first complaint requested a reduction in base ROE transmission formula rates from 12.38% to 9.15% for the time period of Nov. 12, 2013 to Feb. 11, 2015, and removal of ROE adders (including those for RTO membership). The second complaint requested, for a subsequent time period, a base ROE reduction from 12.38% to 8.67%.

The FERC subsequently issued various related orders (including Opinion Nos. 569, 569A and 569B) related to ROE methodology/calculations and timing. NSP-Minnesota has processed refunds to customers for applicable complaint periods based on the ROE in the most recent applicable opinions on behalf of the NSP System.

The MISO TOs and various other parties have filed petitions for review of the FERC’s most recent applicable opinions at the D.C. Circuit. In August 2022, the D.C. Circuit ruled that FERC had not adequately supported its conclusions, vacated FERC’s related orders, and remanded the issue back to FERC for further proceedings, which remain pending.

Environmental

MGP, Landfill and Disposal Sites

NSP-Wisconsin is investigating, remediating or performing post-closure actions at one MGP, landfill or other disposal sites across its service territories.

NSP-Wisconsin has recognized its best estimate of costs/liabilities from final resolution of these issues, however, the outcome and timing are unknown. In addition, there may be insurance recovery and/or recovery from other potentially responsible parties, offsetting a portion of costs incurred.

Environmental Requirements — Water and Waste

Federal Clean Water Act Section 316(b) — The Federal Clean Water Act requires the EPA to regulate cooling water intake structures to assure they reflect the best technology available for minimizing impingement and entrainment of aquatic species. NSP-Wisconsin estimates capital expenditures of approximately $5 million may be required to comply with the requirements. NSP-Wisconsin believes two plants could be required to make improvements to reduce impingement and entrainment. NSP-Wisconsin anticipates these costs will be recoverable through regulatory mechanisms.

10. Segment Information

NSP-Wisconsin evaluates performance based on profit or loss generated from the product or service provided. These segments are managed separately because the revenue streams are dependent upon regulated rate recovery, which is separately determined for each segment.

NSP-Wisconsin has the following reportable segments:

•Regulated Electric — The regulated electric utility segment generates electricity, which is transmitted and distributed in Wisconsin and Michigan.

•Regulated Natural Gas — The regulated natural gas utility segment purchases, transports, stores and distributes natural gas in portions of Wisconsin and Michigan.

Asset and capital expenditure information is not provided for NSP-Wisconsin's reportable segments. As an integrated electric and natural gas utility, NSP-Wisconsin operates significant assets that are not dedicated to a specific business segment. Reporting assets and capital expenditures by business segment would require arbitrary and potentially misleading allocations, which may not necessarily reflect the assets that would be required for the operation of the business segments on a stand-alone basis.

Certain costs, such as common depreciation, common O&M expenses and interest expense are allocated based on cost causation allocators across each segment. In addition, a general allocator is used for certain general and administrative expenses, including office supplies, rent, property insurance and general advertising.

NSP-Wisconsin's segment information:

	Three Months Ended March 31
(Millions of Dollars)	2023		2022
Regulated Electric
Total revenues (a)	$	254	$	250
Net income	33		32
Regulated Natural Gas
Total revenues	$	77	$	78
Net income	11		15
All Other
Net income	$	1	$	—
Consolidated Total
Total revenues (a)	$	331	$	328
Net income	45		47

(a)Total revenues include $50 million and $47 million of affiliate electric revenue for the three months ended March 31, 2023 and 2022, respectively.

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

Discussion of financial condition and liquidity for NSP-Wisconsin is omitted per conditions set forth in General Instructions H(1)(a) and (b) of Form 10-Q for wholly owned subsidiaries. It is replaced with management’s narrative analysis of the results of operations set forth in General Instruction H(2)(a) of Form 10-Q for wholly owned subsidiaries (reduced disclosure format).

Non-GAAP Financial Measures

The following discussion includes financial information prepared in accordance with GAAP, as well as certain non-GAAP financial measures such as ongoing earnings. Generally, a non-GAAP financial measure is a measure of a company’s financial performance, financial position or cash flows that adjusts amounts that are adjusted from measures calculated and presented in accordance with GAAP.

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NSP-Wisconsin’s management uses non-GAAP measures for financial planning and analysis, for reporting of results to the Board of Directors, in determining performance-based compensation and communicating its earnings outlook to analysts and investors. Non-GAAP financial measures are intended to supplement investors’ understanding of our performance and should not be considered alternatives for financial measures presented in accordance with GAAP. These measures are discussed in more detail below and may not be comparable to other companies’ similarly titled non-GAAP financial measures.

Earnings Adjusted for Certain Items (Ongoing Earnings)

Ongoing earnings reflect adjustments to GAAP earnings (net income) for certain items.

We use this non-GAAP financial measure to evaluate and provide details of NSP-Wisconsin’s core earnings and underlying performance. We believe this measurement is useful to investors to evaluate the actual and projected financial performance and contribution of NSP-Wisconsin. For the three months ended March 31, 2023 and 2022, there were no such adjustments to GAAP earnings and therefore GAAP earnings equal ongoing earnings.

Results of Operations

NSP-Wisconsin's net income was $45 million for the three months ended March 31, 2023, compared to $47 million for the prior year. Recovery of electric and natural gas infrastructure investment were more than offset by impacts of warmer winter weather, higher depreciation and O&M expenses.

Electric Margin

Electric margin is presented as electric revenues less electric fuel and purchased power expenses. Expenses incurred for electric fuel and purchased power are generally recovered through various regulatory recovery mechanisms. As a result, changes in these expenses are generally offset in operating revenues.

Electric revenues and fuel and purchased power expenses are impacted by fluctuations in the price of natural gas, coal and uranium. However, these price fluctuations generally have minimal earnings impact due to fuel recovery mechanisms. In addition, electric customers receive a credit for production tax credits generated, which reduce electric revenue and income taxes.

Electric revenues, fuel and purchased power and margin:

	Three Months Ended March 31
(Millions of Dollars)	2023		2022
Electric revenues	$	254	$	250
Electric fuel and purchased power	(107)		(112)
Electric margin	$	147	$	138

(Millions of Dollars)	Three Months Ended March 31, 2023 vs. 2022
Regulatory rate outcomes	$	9
Estimated inpact of weather	(4)
Other (net)	4
Total increase	$	9

Natural Gas Margin

Natural gas margin is presented as natural gas revenues less the cost of natural gas sold and transported. Expenses incurred for the cost of natural gas sold are generally recovered through various regulatory recovery mechanisms. As a result, changes in these expenses are generally offset in operating revenues.

Natural gas expense varies with changing sales and the cost of natural gas. However, fluctuations in the cost of natural gas generally have minimal earnings impact due to cost recovery mechanisms.

Natural gas revenues, cost of natural gas sold and transported and margin:

	Three Months Ended March 31
(Millions of Dollars)	2023		2022
Natural gas revenues	$	77	$	78
Cost of natural gas sold and transported	(46)		(45)
Natural gas margin	$	31	$	33

(Millions of Dollars)	Three Months Ended March 31, 2023 vs. 2022
Regulatory rate outcomes (Wisconsin)	$	2
Estimated impact of weather	(3)
Other (net)	(1)
Total increase	$	(2)

Non-Fuel Operating Expenses and Other Items

O&M Expenses — O&M costs increased $5 million for the first quarter. This was primarily due to higher cost for storms and inflationary pressures including labor increases.

Depreciation and Amortization — Depreciation and amortization increased $3 million for the first quarter, primarily due to normal system expansion.

Public Utility Regulation and Other

The FERC and various state and local regulatory commissions regulate NSP-Wisconsin. The electric and natural gas rates charged to customers of NSP-Wisconsin are approved by the FERC or the regulatory commissions in the states in which it operates.

Rates are designed to recover plant investment, operating costs and an allowed return on investment. NSP-Wisconsin requests changes in utility rates through commission filings.

Changes in operating costs can affect NSP-Wisconsin’s financial results, depending on the timing of rate case filings and implementation of final rates. Other factors affecting rate filings are new investments, sales, conservation and demand side management efforts, and the cost of capital. In addition, the regulatory commissions authorize the ROE, capital structure and depreciation rates in rate proceedings. Decisions by these regulators can significantly impact NSP-Wisconsin’s results of operations.

Except to the extent noted below, the circumstances set forth in Public Utility Regulation included in Item 7 of NSP-Wisconsin’s Annual Report on Form 10-K for the year ended Dec. 31, 2022 appropriately represent, in all material respects, the current status of public utility regulation and are incorporated herein by reference.

Upcoming Regulatory Proceedings

Wisconsin Rate Case — On April 28, 2023, NSP-Wisconsin expects to file a base rate filing with the PSCW seeking an electric increase of $40 million (an overall rate increase of 4.8%) and a natural gas increase of $9 million (an overall rate increase of 5.3%). The rate request is based on a 2024 forward-looking test year with a requested ROE of 10.25% and a 52.5% equity ratio. A final decision by the PSCW is expected late fourth quarter 2023.

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Other

Supply Chain

NSP-Wisconsin’s ability to meet customer energy requirements, respond to storm-related disruptions and execute our capital expenditure program are dependent on maintaining an efficient supply chain. Manufacturing processes have experienced disruptions related to scarcity of certain raw materials and interruptions in production and shipping. These disruptions have been further exacerbated by inflationary pressures, labor shortages and the impact of international conflicts/issues. NSP-Wisconsin continues to monitor the situation as it remains fluid and seeks to mitigate the impacts by securing alternative suppliers, modifying design standards, and adjusting the timing of work.

Electric Meters and Transformers

Supply chain issues associated with semi-conductors have delayed the availability of advanced infrastructure meters. Full 2023 impacts and mitigation plans are currently being evaluated.

Additionally, the availability of certain transformers is an industry-wide issue that has significantly impacted and, in some cases, may result in delays in projects and new customer connections. Proposed governmental actions related to transformer efficiency standards may compound these delays in the future. NSP-Minnesota continues to seek alternative suppliers and prioritize work plans to mitigate impacts of supply constraints.

MISO Capacity Credits

The NSP System offered 1,500 MW of excess capacity into the MISO planning resource auction for June 2022 through May 2023. Due to a projected overall capacity shortfall in the MISO region, the 1,500 MWs offered cleared the auction at maximum pricing and is expected to generate revenues of approximately $90 million in 2022 and approximately $60 million in 2023. During the three months ended March 31, 2023, the NSP System received approximately $40 million of capacity credits. These amounts will primarily be used to mitigate customer rate increases or returned through earnings sharing or other mechanisms.

NSP-Wisconsin's share of the 2023 capacity revenues is expected to be approximately $10 million. These revenues will offset fuel costs through existing fuel recovery mechanisms.

Environmental

Clean Air Act

NOx Allowance Allocations — In March 2023, after disapproving state implementation plans, the EPA released a prepublication version of the final regulations under the "Good Neighbor" provisions of the Clean Air Act. The final rule applies to generation facilities in Minnesota and Wisconsin, as well as other states outside of our service territory. The rule establishes an allowance trading program for NOx that will impact NSP System fossil fuel-fired electric generating facilities in the states within our service territory. Applicable facilities will have to secure additional allowances, install NOx controls and/or develop a strategy of operations that utilizes the existing allowance allocations. Guidelines are also established for allowance banking and emission limit backstops.

While the financial impacts of the final rule are uncertain and dependent on market forces and anticipated generation, NSP-Wisconsin anticipates the annual costs could be significant, but would be recoverable through regulatory mechanisms.

GHG Emissions Limits — It is anticipated the EPA will propose rules to limit GHG emissions from new fossil fuel-fired electric generating units and natural gas-fired stationary combustion units under Clean Air Act Section 111(b) as well as emission guidelines under Clean Air Act Section 111(d) to limit GHG emissions from existing fossil fuel-fired electric generating units in 2023.

If any new rules require additional investment, NSP-Wisconsin believes that the cost of these initiatives or replacement generation would be recoverable through rates based on prior state commission practices.

Coal Ash Regulation

In February 2023, the EPA entered into a Consent Decree committing the agency to either issue new proposed rules by May 5, 2023, to regulate inactive CCR landfills under the CCR Rule for the first time or to determine no such rules are necessary by that date.

If proposed rules are issued, the EPA has committed to a May 2024 effective date for those new rules. It is also anticipated that the EPA may issue other CCR proposed rules in 2023 that further expand the scope of the CCR Rule. Until proposed rules are issued, it is not certain what the impact will be on NSP-Wisconsin.

Emerging Contaminants of Concern

PFAS are man-made chemicals that are widely used in consumer products and can persist and bio-accumulate in the environment. NSP-Wisconsin does not manufacture PFAS but because PFAS are so ubiquitous in products and the environment, it may impact our operations.

In September 2022, the EPA proposed to designate two types of PFAS as “hazardous substances” under the CERCLA.

In March 2023, the EPA published a proposed rule that would establish enforceable drinking water standards for certain PFAS chemicals.

The proposed rules could result in new obligations for investigation and cleanup. NSP-Wisconsin is monitoring changes to state laws addressing PFAS. The impact of these proposed regulations is uncertain.

Effluent Limitation Guidelines

In March 2023, the EPA released a proposed rule under the Clean Water Act, setting forth proposed Effluent Limitations Guidelines and Standards for steam generating coal plants. This proposed rule establishes more stringent wastewater discharge standards for bottom ash transport water, flue-gas desulfurization wastewater, and combustion residuals leachate from steam electric power plants, particularly coal-fired power plants. Comments to the proposed regulations are due May 30, 2023. The impact of these proposed regulations is uncertain.

ITEM 4 — CONTROLS AND PROCEDURES

Disclosure Controls and Procedures

NSP-Wisconsin maintains a set of disclosure controls and procedures designed to ensure that information required to be disclosed in reports that it files or submits under the Securities Exchange Act of 1934 is recorded, processed, summarized, and reported within the time periods specified in SEC rules and forms.

In addition, the disclosure controls and procedures ensure that information required to be disclosed is accumulated and communicated to management, including the CEO and CFO, allowing timely decisions regarding required disclosure.

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As of March 31, 2023, based on an evaluation carried out under the supervision and with the participation of NSP-Wisconsin’s management, including the CEO and CFO, of the effectiveness of its disclosure controls and procedures, the CEO and CFO have concluded that NSP-Wisconsin’s disclosure controls and procedures were effective.

Internal Control Over Financial Reporting

No changes in NSP-Wisconsin’s internal control over financial reporting occurred during the most recent fiscal quarter that materially affected, or are reasonably likely to materially affect, NSP-Wisconsin’s internal control over financial reporting.

PART II — OTHER INFORMATION

ITEM 1 — LEGAL PROCEEDINGS

NSP-Wisconsin is involved in various litigation matters in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. Management maintains accruals for losses probable of being incurred and subject to reasonable estimation.

Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including but not limited to, when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories. In such cases, there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss.

For current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, would have a material effect on NSP-Wisconsin’s consolidated financial statements. Legal fees are generally expensed as incurred.

See Note 9 to the consolidated financial statements and Part I Item 2 for further information.

ITEM 1A — RISK FACTORS

NSP-Wisconsin's risk factors are documented in Item 1A of Part I of its Annual Report on Form 10-K for the year ended Dec. 31, 2022, which is incorporated herein by reference. There have been no material changes from the risk factors previously disclosed in the Form 10-K.

ITEM 6 — EXHIBITS

* Indicates incorporation by reference

Exhibit Number	Description	Report or Registration Statement	Exhibit Reference
3.01*	Amended and Restated Articles of Incorporation of NSP-Wisconsin, dated May 28, 1998	NSP-Wisconsin Form S-4 dated Jan. 21, 2004	3.01
3.02*	Amended and Restated Bylaws of NSP-Wisconsin, dated Jan. 25, 2019	NSP-Wisconsin Form 10-K for the year ended Dec. 31, 2018	3.02
31.01	Principal Executive Officer’s certifications pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
31.02	Principal Financial Officer’s certifications pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002.
32.01	Certifications pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002.
101.INS	Inline XBRL Instance Document - the instance document does not appear in the Interactive Data File because its XBRL tags are embedded within the Inline XBRL document.
101.SCH	Inline XBRL Schema
101.CAL	Inline XBRL Calculation
101.DEF	Inline XBRL Definition
101.LAB	Inline XBRL Label
101.PRE	Inline XBRL Presentation
104	Cover Page Interactive Data File (formatted as Inline XBRL and contained in Exhibit 101)

14

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

		Northern States Power Company (a Wisconsin corporation)
4/27/2023	By:	/s/ BRIAN J. VAN ABEL
		Brian J. Van Abel
		Executive Vice President, Chief Financial Officer
		(Principal Accounting Officer and Principal Financial Officer)

15

EX-31.01

Exhibit 31.01

CERTIFICATION

I, Robert C. Frenzel, certify that:

1.I have reviewed this report on Form 10-Q of Northern States Power Company (a Wisconsin 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 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 Act 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 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: 4/27/2023

/s/ ROBERT C. FRENZEL

Robert C. Frenzel

Chairman, Chief Executive Officer and Director

(Principal Executive Officer)

1

EX-31.02

Exhibit 31.02

CERTIFICATION

I, Brian J. Van Abel, certify that:

1.I have reviewed this report on Form 10-Q of Northern States Power Company (a Wisconsin 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 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 Act 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 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: 4/27/2023

/s/ BRIAN J. VAN ABEL

Brian J. Van Abel

Executive Vice President, Chief Financial Officer and Director

(Principal Accounting Officer and Principal Financial Officer)

2

EX-32.01

Exhibit 32.01

OFFICER CERTIFICATION

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 Northern States Power Company, a Wisconsin Corporation (NSP-Wisconsin) on Form 10-Q for the quarter ended March 31, 2023, as filed with the SEC on the date hereof (Form 10-Q), each of the undersigned officers of NSP-Wisconsin certifies, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to such officer’s knowledge:

(1)The Form 10-Q 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 Form 10-Q fairly presents, in all material respects, the financial condition and results of operations of NSP-Wisconsin as of the dates and for the periods expressed in the Form 10-Q.

Date: 4/27/2023

/s/ ROBERT C. FRENZEL

Robert C. Frenzel

Chairman, Chief Executive Officer and Director

(Principal Executive Officer)

/s/ BRIAN J. VAN ABEL

Brian J. Van Abel

Executive Vice President, Chief Financial Officer and Director

(Principal Accounting Officer and Principal Financial Officer)

The foregoing certification is being furnished solely pursuant to 18 U.S.C. Section 1350 and is not being filed as part of the Report or as a separate disclosure document.

A signed original of this written statement required by Section 906, or other document authenticating, acknowledging or otherwise adopting the signature that appears in typed form within the electronic version of this written statement required by Section 906, has been provided to NSP-Wisconsin and will be retained by NSP-Wisconsin and furnished to the SEC or its staff upon request.

1

XML

Cover Page - shares	3 Months Ended
	Mar. 31, 2023	Apr. 27, 2023
Cover [Abstract]
Entity Registrant Name	NORTHERN STATES POWER CO /WI/
Entity Central Index Key	0000072909
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1
Amendment Flag	false
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2023
Document Transition Report	false
Entity File Number	001-03140
Entity Incorporation, State or Country Code	WI
Entity Tax Identification Number	39-0508315
Entity Address, Address Line One	1414 West Hamilton Avenue
Entity Address, City or Town	Eau Claire
Entity Address, State or Province	WI
Entity Address, Postal Zip Code	54701
City Area Code	(715)
Local Phone Number	737-2625
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		933,000

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CONSOLIDATED STATEMENTS OF INCOME (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating revenues
Electric, non-affiliates	$ 204	$ 203
Electric, affiliates	50	47
Natural gas	77	78
Total operating revenues	331	328
Operating expenses
Electric fuel and purchased power, non-affiliates	4	4
Purchased power, affiliates	103	108
Cost of natural sold and transported	46	45
Operating and maintenance expenses	58	53
Conservation program expenses	3	3
Depreciation and amortization	41	38
Taxes (other than income taxes)	8	8
Total operating expenses	263	259
Operating income	68	69
Allowance for funds used during construction — equity	2	2
Interest charges and financing costs
Interest charges	13	11
Allowance for funds used during construction — debt	(1)	(1)
Total interest charges and financing costs	12	10
Income before income taxes	58	61
Income tax expense	13	14
Net income	$ 45	$ 47

XML

CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities
Net income	$ 45	$ 47
Adjustments to reconcile net income to cash provided by operating activities:
Depreciation and amortization	42	39
Deferred income taxes	(2)	(1)
Allowance for equity funds used during construction	2	2
Provision for bad debts	2	2
Changes in operating assets and liabilities:
Accounts receivable	(16)	(17)
Accrued unbilled revenues	20	18
Inventories	15	4
Other current assets	13	5
Accounts payable	(10)	(8)
Net regulatory assets and liabilities	17	4
Other current liabilities	0	15
Pension and other employee benefit obligations	(3)	(1)
Other, net	1	3
Net cash provided by operating activities	122	108
Investing activities
Capital/construction expenditures	(101)	(87)
Net cash used in investing activities	(101)	(87)
Financing activities
Repayments of short-term borrowings, net	(35)	(83)
Borrowings under utility money pool arrangement	0	235
Repayments under utility money pool arrangement	0	(187)
Capital contributions from parent	36	31
Dividends paid to parent	(23)	(27)
Other, net	0	1
Net cash used in financing activities	(22)	(30)
Net change in cash, cash equivalents and restricted cash	(1)	(9)
Cash, cash equivalents and restricted cash at beginning of period	2	11
Cash, cash equivalents and restricted cash at end of period	1	2
Supplemental disclosure of cash flow information:
Cash paid for interest (net of amounts capitalized)	(13)	(10)
Cash paid for income taxes, net	(4)	0
Supplemental disclosure of non-cash investing and financing transactions:
Accrued property, plant and equipment additions	33	17
Inventory transfers to property, plant and equipment	2	1
Allowance for equity funds used during construction	$ 2	$ 2

XML

CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Current assets
Cash and cash equivalents	$ 1	$ 2
Accounts receivable, net	92	84
Accrued unbilled revenues	53	74
Other receivables	14	19
Inventories	23	39
Regulatory assets	37	44
Prepaid taxes	21	27
Prepayments and other	8	11
Total current assets	249	300
Property, Plant and Equipment, Net [Abstract]
Property, plant and equipment, net	2,971	2,914
Other assets
Regulatory assets	189	193
Other	3	3
Total other assets	192	196
Total assets	3,412	3,410
Current liabilities
Short-term debt	12	47
Accounts payable	58	92
Accounts payable to affiliates	26	19
Dividends payable to parent	24	23
Regulatory liabilities	26	21
Taxes accrued	22	13
Accrued interest	10	12
Other	20	28
Total current liabilities	198	255
Deferred credits and other liabilities
Deferred income taxes	334	333
Deferred investment tax credits	5	5
Regulatory liabilities	393	383
Customer advances	23	23
Pension and employee benefit obligations	20	23
Other	42	43
Total deferred credits and other liabilities	817	810
Commitments and contingencies
Capitalization
Long-term debt	1,087	1,086
Common stock — 1,000,000 shares authorized of $100 par value; 933,000 shares outstanding at March 31, 2023 and Dec. 31, 2022, respectively	$ 93	$ 93
Common stock, shares authorized (in shares)	1,000,000	1,000,000
Common stock, par value (in dollars per share)	$ 100	$ 100
Common stock, shares outstanding (in shares)	933,000	933,000
Additional paid in capital	$ 791	$ 761
Retained earnings	426	405
Total common stockholder's equity	1,310	1,259
Total liabilities and equity	$ 3,412	$ 3,410

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CONSOLIDATED STATEMENTS OF COMMON STOCKHOLDER'S EQUITY - USD ($) $ in Millions	Total	Common stock	Additional Paid In Capital	Retained Earnings
Balance (in shares) at Dec. 31, 2021		933,000
Beginning Balance at Dec. 31, 2021	$ 1,103	$ 93	$ 642	$ 368
Increase (Decrease) in Stockholder's Equity
Net income	47			47
Common dividends declared to parent	(22)			(22)
Contribution of capital by parent	30		30
Balance (in shares) at Mar. 31, 2022		933,000
Ending Balance at Mar. 31, 2022	$ 1,158	$ 93	672	393
Balance (in shares) at Dec. 31, 2022	933,000	933,000
Beginning Balance at Dec. 31, 2022	$ 1,259	$ 93	761	405
Increase (Decrease) in Stockholder's Equity
Net income	45			45
Common dividends declared to parent	(24)			(24)
Contribution of capital by parent	$ 30		30
Balance (in shares) at Mar. 31, 2023	933,000	933,000
Ending Balance at Mar. 31, 2023	$ 1,310	$ 93	$ 791	$ 426

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Management's Opinion

3 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Management's Opinion

In the opinion of management, the accompanying unaudited consolidated financial statements contain all adjustments necessary to present fairly, in accordance with GAAP, the financial position of NSP-Wisconsin and its subsidiaries as of March 31, 2023 and Dec. 31, 2022; the results of NSP-Wisconsin's operations, including the components of net income, changes in stockholder's equity and comprehensive income for the three months ended March 31, 2023 and 2022; and NSP-Wisconsin's cash flows for the three months ended March 31, 2023 and 2022.

All adjustments are of a normal, recurring nature, except as otherwise disclosed. Management has also evaluated the impact of events occurring after March 31, 2023 up to the date of issuance of these consolidated financial statements. These statements contain all necessary adjustments and disclosures resulting from that evaluation. The Dec. 31, 2022 balance sheet information has been derived from the audited 2022 consolidated financial statements included in the NSP-Wisconsin Annual Report on Form 10-K for the year ended Dec. 31, 2022.

Notes to the consolidated financial statements have been prepared pursuant to the rules and regulations of the SEC for Quarterly Reports on Form 10-Q. Certain information and note disclosures normally included in financial statements prepared in accordance with GAAP on an annual basis have been condensed or omitted pursuant to such rules and regulations. For further information, refer to the consolidated financial statements and notes thereto included in the NSP-Wisconsin Annual Report on Form 10-K for the year ended Dec. 31, 2022, filed with the SEC on Feb. 23, 2023. Due to the seasonality of NSP-Wisconsin’s electric and natural gas sales, interim results are not necessarily an appropriate base from which to project annual results.

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Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2023
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	The significant accounting policies set forth in Note 1 to the consolidated financial statements in the NSP-Wisconsin Annual Report on Form 10-K for the year ended Dec. 31, 2022 appropriately represent, in all material respects, the current status of accounting policies and are incorporated herein by reference.

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Accounting Pronouncements	3 Months Ended
	Mar. 31, 2023
Accounting Standards Update and Change in Accounting Principle [Abstract]
Accounting Pronouncements	As of March 31, 2023, there was no material impact from the recent adoption of new accounting pronouncements, nor expected material impact from recently issued accounting pronouncements yet to be adopted, on NSP-Wisconsin's consolidated financial statements.

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Selected Balance Sheet Data

3 Months Ended

Mar. 31, 2023

Balance Sheet Related Disclosures [Abstract]

Selected Balance Sheet Data

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Accounts receivable, net
Accounts receivable	$	101	$	93
Less allowance for bad debts	(9)		(9)
Accounts receivable, net	$	92	$	84

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Inventories
Materials and supplies	$	9	$	8
Fuel	11		11
Natural gas	3		20
Total inventories	$	23	$	39

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Property, plant and equipment, net
Electric plant	$	3,649	$	3,579
Natural gas plant	471		465
Common and other property	264		260
Construction work in progress	172		174
Total property, plant and equipment	4,556		4,478
Less accumulated depreciation	(1,585)		(1,564)
Property, plant and equipment, net	$	2,971	$	2,914

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Borrowings and Other Financing Instruments

3 Months Ended

Mar. 31, 2023

Debt Disclosure [Abstract]

Borrowings and Other Financing Instruments

Short-Term Borrowings

NSP-Wisconsin meets its short-term liquidity requirements primarily through the issuance of commercial paper and borrowings under its credit facility and the money pool.

Money Pool — Xcel Energy Inc. and its utility subsidiaries have established a money pool arrangement that allows for short-term investments in and borrowings between the utility subsidiaries. Xcel Energy Inc. may make investments in the utility subsidiaries at market-based interest rates; however, the money pool arrangement does not allow the utility subsidiaries to make investments in Xcel Energy Inc.

Money pool borrowings:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2023		Year Ended Dec. 31, 2022
Borrowing limit	$	150	$	150
Amount outstanding at period end	—		—
Average amount outstanding	—		25
Maximum amount outstanding	—		81
Weighted average interest rate, computed on a daily basis	N/A		1.10		%
Weighted average interest rate at period end	N/A		N/A

Commercial Paper — Commercial paper outstanding:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2023			Year Ended Dec. 31, 2022
Borrowing limit	$	150		$	150
Amount outstanding at period end	12			47
Average amount outstanding	48			18
Maximum amount outstanding	93			123
Weighted average interest rate, computed on a daily basis	4.71		%	1.03		%
Weighted average interest rate at period end	5.05			4.55

Letters of Credit — NSP-Wisconsin uses letters of credit, generally with terms of one year, to provide financial guarantees for certain obligations. At both March 31, 2023 and Dec. 31, 2022, there were no letters of credit outstanding under the credit facility.

Revolving Credit Facility — In order to issue its commercial paper, NSP-Wisconsin must have a revolving credit facility equal or greater than the commercial paper borrowing limit and cannot issue commercial paper exceeding available capacity under this credit facility. The credit facility provides short-term financing in the form of notes payable to banks, letters of credit and back-up support for commercial paper borrowings.

NSP-Wisconsin has the right to request an extension of the revolving credit facility termination date for an additional one-year period. All extension requests are subject to majority bank group approval.

As of March 31, 2023, NSP-Wisconsin had the following committed revolving credit facility available (in millions of dollars):

Credit Facility (a)		Outstanding (b)		Available
$	150	$	12	$	138

(a)Expires in September 2027.

(b)Includes outstanding commercial paper.

All credit facility bank borrowings, outstanding letters of credit and outstanding commercial paper reduce the available capacity under the credit facility. NSP-Wisconsin had no direct advances on the credit facility outstanding at March 31, 2023 and Dec. 31, 2022.

Other Short-Term Borrowings — Clearwater Investments, Inc., a NSP-Wisconsin subsidiary, had an immaterial note payable to Xcel Energy Inc. as of March 31, 2023 and Dec. 31, 2022, respectively.

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Revenues

3 Months Ended

Mar. 31, 2023

Revenue from Contract with Customer [Abstract]

Revenues

Revenue is classified by the type of goods/services rendered and market/customer type. NSP-Wisconsin’s operating revenues consisted of the following:

	Three Months Ended March 31, 2023
(Millions of Dollars)	Electric		Natural Gas		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	82	$	41	$	123
C&I	120		34		154
Other	2		—		2
Total retail	204		75		279
Interchange	50		—		50
Other	(3)		1		(2)
Total revenue from contracts with customers	251		76		327
Alternative revenue and other	3		1		4
Total revenues	$	254	$	77	$	331

	Three Months Ended March 31, 2022
(Millions of Dollars)	Electric		Natural Gas		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	81	$	42	$	123
C&I	116		34		150
Other	2		—		2
Total retail	199		76		275
Interchange	47		—		47
Other	1		1		2
Total revenue from contracts with customers	247		77		324
Alternative revenue and other	3		1		4
Total revenues	$	250	$	78	$	328

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Income Taxes

3 Months Ended

Mar. 31, 2023

Income Tax Disclosure [Abstract]

Income Taxes

6. Income Taxes

Reconciliation between the statutory rate and effective tax rate:

	Three Months Ended March 31
	2023		2022
Federal statutory rate	21.0	%	21.0	%
State tax (net of federal tax effect)	6.2		6.2
Decreases:
Plant regulatory differences (a)	(3.5)		(3.7)
Other (net)	(1.3)		(0.5)
Effective income tax rate	22.4	%	23.0	%

(a)Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

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Fair Value of Financial Assets and Liabilities

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value of Financial Assets and Liabilities

7. Fair Value of Financial Assets and Liabilities

Fair Value Measurements

Accounting guidance for fair value measurements and disclosures provides a hierarchical framework for disclosing the observability of the inputs utilized in measuring assets and liabilities at fair value.

•Level 1 — Quoted prices are available in active markets for identical assets or liabilities as of the reporting date. The types of assets and liabilities included in Level 1 are actively traded instruments with observable actual trading prices.

•Level 2 — Pricing inputs are other than actual trading prices in active markets, but are either directly or indirectly observable as of the reporting date. The types of assets and liabilities included in Level 2 are typically either comparable to actively traded securities or contracts or priced with models using highly observable inputs.

•Level 3 — Significant inputs to pricing have little or no observability as of the reporting date. The types of assets and liabilities included in Level 3 include those valued with models requiring significant judgment or estimation.

Specific valuation methods include:

Commodity Derivatives — Methods used to measure the fair value of commodity derivative forwards and options utilize forward prices and volatilities, as well as pricing adjustments for specific delivery locations, and are generally assigned a Level 2 classification. When contracts relate to inactive delivery locations or extend to periods beyond those readily observable on active exchanges, the significance of the use of less observable inputs on a valuation is evaluated, and may result in Level 3 classification.

Derivative Activities and Fair Value Measurements

NSP-Wisconsin enters into derivative instruments, including forward contracts, futures, swaps and options, to manage risk in connection with changes in utility commodity prices.

Commodity Derivatives — NSP-Wisconsin enters into derivative instruments to manage variability of future cash flows from changes in commodity prices in its electric and natural gas operations. This could include the purchase or sale of natural gas to generate electric energy and natural gas for resale.

As of March 31, 2023, NSP-Wisconsin had no commodity contracts designated as cash flow hedges.

Consideration of Credit Risk and Concentrations — NSP-Wisconsin continuously monitors the creditworthiness of counterparties to its interest rate derivatives and commodity derivative contracts prior to settlement, and assesses each counterparty’s ability to perform on the transactions set forth in the contracts. Impact of credit risk was immaterial to the fair value of unsettled commodity derivatives presented on the consolidated balance sheets.

Recurring Derivative Fair Value Measurements

Impact of derivative activity:

Changes in the fair value of natural gas commodity derivatives resulted in $1 million of net gains for the three months ended March 31, 2023, which were recognized as regulatory assets and liabilities. The classification as a regulatory asset or liability is based on commission approved regulatory recovery mechanisms. Immaterial net gains were recognized for the three months ended March 31, 2022.

During the three months ended March 31, 2023 and 2022, there were immaterial natural gas commodity derivatives settlement losses and gains.

During the three months ended March 31, 2023, $2 million of pre-tax losses were recognized during the period in income related to option premium amortization. During the three months ended March 31, 2022, similar activity was immaterial.

NSP-Wisconsin had no outstanding derivative assets or liabilities measured at fair value as of March 31, 2023. Derivative assets and liabilities measured at fair value on a recurring basis were as follows as of Dec. 31, 2022:

	Dec. 31, 2022
	Fair Value						Fair Value Total		Netting (a)		Total
(Millions of Dollars)	Level 1		Level 2		Level 3
Current derivative assets
Natural gas commodity (b)	$	—	$	2	$	—	$	2	$	—	$	2
Current derivative liabilities
Natural gas commodity (b)	$	—	$	1	$	—	$	1	$	—	$	1

(a)NSP-Wisconsin nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

(b)$2 million included in prepayments and other current assets and $1 million included in other current liabilities at Dec. 31, 2022 on the consolidated balance sheet.

Fair Value of Long-Term Debt

As of March 31, 2023, other financial instruments for which the carrying amount did not equal fair value:

	March 31, 2023				Dec. 31, 2022
(Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt, including current portion	$	1,087	$	1,006	$	1,086	$	980

Fair value of NSP-Wisconsin’s long-term debt is estimated based on recent trades and observable spreads from benchmark interest rates for similar securities. Fair value estimates are based on information available to management as of March 31, 2023 and Dec. 31, 2022 and given the observability of the inputs, fair values presented for long-term debt were assigned as Level 2.

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Benefit Plans and Other Postretirement Benefits

3 Months Ended

Mar. 31, 2023

Retirement Benefits [Abstract]

Benefit Plans and Other Postretirement Benefits

Components of Net Periodic Benefit Cost

	Three Months Ended March 31
	2023		2022
(Millions of Dollars)	Pension Benefits
Service cost	$	1	$	1
Interest cost (a)	2		1
Expected return on plan assets (a)	(2)		(2)
Amortization of net loss (a)	—		1
Net benefit cost recognized for financial reporting	$	1	$	1

(a)The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.

In January 2023, contributions totaling $50 million were made across Xcel Energy’s pension plans, of which $4 million was attributable to NSP-Wisconsin. Xcel Energy does not expect additional pension contributions during 202

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Commitments and Contingencies

3 Months Ended

Mar. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Legal

NSP-Wisconsin is involved in various litigation matters in the ordinary course of business. The assessment of whether a loss is probable or is a reasonable possibility, and whether the loss or a range of loss is estimable, often involves a series of complex judgments about future events. Management maintains accruals for losses probable of being incurred and subject to reasonable estimation. Management is sometimes unable to estimate an amount or range of a reasonably possible loss in certain situations, including but not limited to when (1) the damages sought are indeterminate, (2) the proceedings are in the early stages, or (3) the matters involve novel or unsettled legal theories.

In such cases, there is considerable uncertainty regarding the timing or ultimate resolution, including a possible eventual loss. For current proceedings not specifically reported herein, management does not anticipate that the ultimate liabilities, if any, would have a material effect on NSP-Wisconsin’s consolidated financial statements. Legal fees are generally expensed as incurred.

Gas Trading Litigation — e prime is a wholly owned subsidiary of Xcel Energy. e prime was in the business of natural gas trading and marketing but has not engaged in natural gas trading or marketing activities since 2003. Multiple lawsuits involving multiple plaintiffs seeking monetary damages were commenced against e prime and its affiliates, including Xcel Energy, between 2003 and 2009 alleging fraud and anticompetitive activities in conspiring to restrain the trade of natural gas and manipulate natural gas prices. Cases were all consolidated in the U.S. District Court in Nevada.

One case remains active which includes a multi-district litigation matter consisting of a Wisconsin purported class (Arandell Corp.). The Court issued a ruling in June 2022 granting plaintiffs’ class certification. In April 2023, the Seventh Circuit Court of Appeals heard the defendants’ appeal challenging whether the district court properly assessed class certification. A decision relating to class certification is expected later this year. Xcel Energy considers the reasonably possible loss associated with this litigation to be immaterial.

Rate Matters

NSP-Wisconsin is involved in various regulatory proceedings arising in the ordinary course of business. Until resolution, typically in the form of a rate order, uncertainties may exist regarding the ultimate rate treatment for certain activities and transactions. Amounts have been recognized for probable and reasonably estimable losses that may result. Unless otherwise disclosed, any reasonably possible range of loss in excess of any recognized amount is not expected to have a material effect on the financial statements.

MISO ROE Complaints — In November 2013 and February 2015, customer groups filed two ROE complaints against MISO TOs, which includes NSP-Minnesota and NSP-Wisconsin. The first complaint requested a reduction in base ROE transmission formula rates from 12.38% to 9.15% for the time period of Nov. 12, 2013 to Feb. 11, 2015, and removal of ROE adders (including those for RTO membership). The second complaint requested, for a subsequent time period, a base ROE reduction from 12.38% to 8.67%.

The FERC subsequently issued various related orders (including Opinion Nos. 569, 569A and 569B) related to ROE methodology/calculations and timing. NSP-Minnesota has processed refunds to customers for applicable complaint periods based on the ROE in the most recent applicable opinions on behalf of the NSP System.

The MISO TOs and various other parties have filed petitions for review of the FERC’s most recent applicable opinions at the D.C. Circuit. In August 2022, the D.C. Circuit ruled that FERC had not adequately supported its conclusions, vacated FERC’s related orders, and remanded the issue back to FERC for further proceedings, which remain pending.

Environmental

MGP, Landfill and Disposal Sites

NSP-Wisconsin is investigating, remediating or performing post-closure actions at one MGP, landfill or other disposal sites across its service territories.

NSP-Wisconsin has recognized its best estimate of costs/liabilities from final resolution of these issues, however, the outcome and timing are unknown. In addition, there may be insurance recovery and/or recovery from other potentially responsible parties, offsetting a portion of costs incurred.

Environmental Requirements — Water and Waste

Federal Clean Water Act Section 316(b) — The Federal Clean Water Act requires the EPA to regulate cooling water intake structures to assure they reflect the best technology available for minimizing impingement and entrainment of aquatic species. NSP-Wisconsin estimates capital expenditures of approximately $5 million may be required to comply with the requirements. NSP-Wisconsin believes two plants could be required to make improvements to reduce impingement and entrainment. NSP-Wisconsin anticipates these costs will be recoverable through regulatory mechanisms.

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Segment Information

3 Months Ended

Mar. 31, 2023

Segment Reporting [Abstract]

Segment Information

NSP-Wisconsin evaluates performance based on profit or loss generated from the product or service provided. These segments are managed separately because the revenue streams are dependent upon regulated rate recovery, which is separately determined for each segment.

NSP-Wisconsin has the following reportable segments:

•Regulated Electric — The regulated electric utility segment generates electricity, which is transmitted and distributed in Wisconsin and Michigan.

•Regulated Natural Gas — The regulated natural gas utility segment purchases, transports, stores and distributes natural gas in portions of Wisconsin and Michigan.

Asset and capital expenditure information is not provided for NSP-Wisconsin's reportable segments. As an integrated electric and natural gas utility, NSP-Wisconsin operates significant assets that are not dedicated to a specific business segment. Reporting assets and capital expenditures by business segment would require arbitrary and potentially misleading allocations, which may not necessarily reflect the assets that would be required for the operation of the business segments on a stand-alone basis.

Certain costs, such as common depreciation, common O&M expenses and interest expense are allocated based on cost causation allocators across each segment. In addition, a general allocator is used for certain general and administrative expenses, including office supplies, rent, property insurance and general advertising.

NSP-Wisconsin's segment information:

	Three Months Ended March 31
(Millions of Dollars)	2023		2022
Regulated Electric
Total revenues (a)	$	254	$	250
Net income	33		32
Regulated Natural Gas
Total revenues	$	77	$	78
Net income	11		15
All Other
Net income	$	1	$	—
Consolidated Total
Total revenues (a)	$	331	$	328
Net income	45		47

(a)Total revenues include $50 million and $47 million of affiliate electric revenue for the three months ended March 31, 2023 and 2022, respectively.

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Selected Balance Sheet Data (Tables)

3 Months Ended

Mar. 31, 2023

Balance Sheet Related Disclosures [Abstract]

Accounts Receivable, Net

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Accounts receivable, net
Accounts receivable	$	101	$	93
Less allowance for bad debts	(9)		(9)
Accounts receivable, net	$	92	$	84

Inventories

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Inventories
Materials and supplies	$	9	$	8
Fuel	11		11
Natural gas	3		20
Total inventories	$	23	$	39

Property, Plant and Equipment, Net

(Millions of dollars)	March 31, 2023		Dec. 31, 2022
Property, plant and equipment, net
Electric plant	$	3,649	$	3,579
Natural gas plant	471		465
Common and other property	264		260
Construction work in progress	172		174
Total property, plant and equipment	4,556		4,478
Less accumulated depreciation	(1,585)		(1,564)
Property, plant and equipment, net	$	2,971	$	2,914

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Borrowings and Other Financing Instruments (Tables)

3 Months Ended

Mar. 31, 2023

Borrowings and Other Financing Instruments [Abstract]

Credit Facilities

As of March 31, 2023, NSP-Wisconsin had the following committed revolving credit facility available (in millions of dollars):

Credit Facility (a)		Outstanding (b)		Available
$	150	$	12	$	138

(a)Expires in September 2027.

(b)Includes outstanding commercial paper.

Money Pool

Borrowings and Other Financing Instruments [Abstract]

Short-Term Borrowings

Money pool borrowings:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2023		Year Ended Dec. 31, 2022
Borrowing limit	$	150	$	150
Amount outstanding at period end	—		—
Average amount outstanding	—		25
Maximum amount outstanding	—		81
Weighted average interest rate, computed on a daily basis	N/A		1.10		%
Weighted average interest rate at period end	N/A		N/A

Commercial Paper

Borrowings and Other Financing Instruments [Abstract]

Short-Term Borrowings

Commercial paper outstanding:

(Amounts in Millions, Except Interest Rates)	Three Months Ended March 31, 2023			Year Ended Dec. 31, 2022
Borrowing limit	$	150		$	150
Amount outstanding at period end	12			47
Average amount outstanding	48			18
Maximum amount outstanding	93			123
Weighted average interest rate, computed on a daily basis	4.71		%	1.03		%
Weighted average interest rate at period end	5.05			4.55

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Revenues (Tables)

3 Months Ended

Mar. 31, 2023

Revenue from Contract with Customer [Abstract]

Disaggregation of revenue

NSP-Wisconsin’s operating revenues consisted of the following:

	Three Months Ended March 31, 2023
(Millions of Dollars)	Electric		Natural Gas		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	82	$	41	$	123
C&I	120		34		154
Other	2		—		2
Total retail	204		75		279
Interchange	50		—		50
Other	(3)		1		(2)
Total revenue from contracts with customers	251		76		327
Alternative revenue and other	3		1		4
Total revenues	$	254	$	77	$	331

	Three Months Ended March 31, 2022
(Millions of Dollars)	Electric		Natural Gas		Total
Major revenue types
Revenue from contracts with customers:
Residential	$	81	$	42	$	123
C&I	116		34		150
Other	2		—		2
Total retail	199		76		275
Interchange	47		—		47
Other	1		1		2
Total revenue from contracts with customers	247		77		324
Alternative revenue and other	3		1		4
Total revenues	$	250	$	78	$	328

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Income Taxes (Tables)

3 Months Ended

Mar. 31, 2023

Income Tax Disclosure [Abstract]

Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]

Reconciliation between the statutory rate and effective tax rate:

	Three Months Ended March 31
	2023		2022
Federal statutory rate	21.0	%	21.0	%
State tax (net of federal tax effect)	6.2		6.2
Decreases:
Plant regulatory differences (a)	(3.5)		(3.7)
Other (net)	(1.3)		(0.5)
Effective income tax rate	22.4	%	23.0	%

(a)Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

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Fair Value of Financial Assets and Liabilities (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Derivative Assets and Liabilities Measured at Fair Value on a Recurring Basis by Hierarchy Level

Recurring Derivative Fair Value Measurements

Impact of derivative activity:

Changes in the fair value of natural gas commodity derivatives resulted in $1 million of net gains for the three months ended March 31, 2023, which were recognized as regulatory assets and liabilities. The classification as a regulatory asset or liability is based on commission approved regulatory recovery mechanisms. Immaterial net gains were recognized for the three months ended March 31, 2022.

During the three months ended March 31, 2023 and 2022, there were immaterial natural gas commodity derivatives settlement losses and gains.

During the three months ended March 31, 2023, $2 million of pre-tax losses were recognized during the period in income related to option premium amortization. During the three months ended March 31, 2022, similar activity was immaterial.

NSP-Wisconsin had no outstanding derivative assets or liabilities measured at fair value as of March 31, 2023. Derivative assets and liabilities measured at fair value on a recurring basis were as follows as of Dec. 31, 2022:

	Dec. 31, 2022
	Fair Value						Fair Value Total		Netting (a)		Total
(Millions of Dollars)	Level 1		Level 2		Level 3
Current derivative assets
Natural gas commodity (b)	$	—	$	2	$	—	$	2	$	—	$	2
Current derivative liabilities
Natural gas commodity (b)	$	—	$	1	$	—	$	1	$	—	$	1

(a)NSP-Wisconsin nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

(b)$2 million included in prepayments and other current assets and $1 million included in other current liabilities at Dec. 31, 2022 on the consolidated balance sheet.

Carrying Amount and Fair Value of Long-term Debt

	March 31, 2023				Dec. 31, 2022
(Millions of Dollars)	Carrying Amount		Fair Value		Carrying Amount		Fair Value
Long-term debt, including current portion	$	1,087	$	1,006	$	1,086	$	980

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Benefit Plans and Other Postretirement Benefits (Tables)

3 Months Ended

Mar. 31, 2023

Retirement Benefits [Abstract]

Components of Net Periodic Benefit Cost

Components of Net Periodic Benefit Cost

	Three Months Ended March 31
	2023		2022
(Millions of Dollars)	Pension Benefits
Service cost	$	1	$	1
Interest cost (a)	2		1
Expected return on plan assets (a)	(2)		(2)
Amortization of net loss (a)	—		1
Net benefit cost recognized for financial reporting	$	1	$	1

(a)The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.

In January 2023, contributions totaling $50 million were made across Xcel Energy’s pension plans, of which $4 million was attributable to NSP-Wisconsin. Xcel Energy does not expect additional pension contributions during 2023.

^[1]

[1] The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.

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Segment Reporting (Tables)

3 Months Ended

Mar. 31, 2023

Segment Reporting [Abstract]

Schedule of Segment Reporting Information, by Segment

NSP-Wisconsin's segment information:

	Three Months Ended March 31
(Millions of Dollars)	2023		2022
Regulated Electric
Total revenues (a)	$	254	$	250
Net income	33		32
Regulated Natural Gas
Total revenues	$	77	$	78
Net income	11		15
All Other
Net income	$	1	$	—
Consolidated Total
Total revenues (a)	$	331	$	328
Net income	45		47

(a)Total revenues include $50 million and $47 million of affiliate electric revenue for the three months ended March 31, 2023 and 2022, respectively.

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Selected Balance Sheet Data - Accounts Receivable (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Accounts Receivable, Net
Accounts receivable	$ 101	$ 93
Less allowance for bad debts	(9)	(9)
Accounts receivable, net	$ 92	$ 84

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Selected Balance Sheet Data - Inventories (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Inventory [Line Items]
Total Inventories	$ 23	$ 39
Materials and supplies
Inventory [Line Items]
Inventories	9	8
Fuel
Inventory [Line Items]
Inventories	11	11
Natural gas
Inventory [Line Items]
Inventories	$ 3	$ 20

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Selected Balance Sheet Data - Property, Plant and Equipment (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 4,556	$ 4,478
Less accumulated depreciation	(1,585)	(1,564)
Property, plant and equipment, net	2,971	2,914
Electric plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,649	3,579
Natural gas plant
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	471	465
Common and other property
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	264	260
Construction work in progress
Public Utility, Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 172	$ 174

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Borrowings and Other Financing Instruments, Commercial Paper (Details) - USD ($)		3 Months Ended	12 Months Ended
		Mar. 31, 2023	Dec. 31, 2022
Short-term Debt [Line Items]
Amount outstanding at period end		$ 12,000,000	$ 47,000,000
Credit Facility
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity	[1]	150,000,000
Long-term Line of Credit		0	0
Payable to Affiliates
Short-term Debt [Line Items]
Notes Payable, Related Parties, Current		0	0
Commercial Paper
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		150,000,000	150,000,000
Amount outstanding at period end		12,000,000	47,000,000
Average amount outstanding		48,000,000	18,000,000
Maximum amount outstanding		$ 93,000,000	$ 123,000,000
Weighted average interest rate, computed on a daily basis		4.71%	1.03%
Weighted average interest rate at period end		5.05%	4.55%
Money Pool
Short-term Debt [Line Items]
Line of Credit Facility, Maximum Borrowing Capacity		$ 150,000,000	$ 150,000,000
Amount outstanding at period end		0	0
Average amount outstanding		0	25,000,000
Maximum amount outstanding		$ 0	$ 81,000,000
Weighted average interest rate, computed on a daily basis			1.10%

[1] Expires in September 2027.

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Borrowings and Other Financing Instruments, Letters of Credit (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Line of Credit Facility [Line Items]
Line of Credit Facility, Expiration Period	1 year
Amount outstanding at period end	$ 12,000,000	$ 47,000,000
Credit Facility
Line of Credit Facility [Line Items]
Long-term Line of Credit	$ 0	$ 0

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Borrowings and Other Financing Instruments, Credit Facility (Details) - Credit Facility - USD ($)		Mar. 31, 2023	Dec. 31, 2022
Line of Credit Facility [Line Items]
Credit Facility	[1]	$ 150,000,000
Outstanding	[2]	12,000,000
Available		138,000,000
Direct advances on the credit facility outstanding		$ 0	$ 0

[1] Expires in September 2027.

[2] Includes outstanding commercial paper.

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Borrowings and Other Financing Instruments (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Series Due June 15, 2053 | Bonds [Member] | PSCo
Short-term Debt [Line Items]
Debt Instrument, Face Amount	$ 125.0
Debt Instrument, Interest Rate, Stated Percentage	5.30%
Payable to Affiliates
Short-term Debt [Line Items]
Notes Payable, Related Parties, Current	$ 0.0	$ 0.0

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Revenues (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	$ 331	$ 328
Regulated Electric | Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	254	250
Regulated Natural Gas | Total revenues
Disaggregation of Revenue [Line Items]
Total revenues	77	78
Retail
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	279	275
Retail | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	123	123
Retail | C&I
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	154	150
Retail | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2	2
Retail | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	204	199
Retail | Regulated Electric | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	82	81
Retail | Regulated Electric | C&I
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	120	116
Retail | Regulated Electric | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2	2
Retail | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	75	76
Retail | Regulated Natural Gas | Residential
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	41	42
Retail | Regulated Natural Gas | C&I
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	34	34
Retail | Regulated Natural Gas | Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Interchange
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	50	47
Interchange | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	50	47
Interchange | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Other
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(2)	2
Other | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(3)	1
Other | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1	1
Total revenue from contracts with customers
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	327	324
Total revenue from contracts with customers | Regulated Electric
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	251	247
Total revenue from contracts with customers | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	76	77
Alternative revenue and other
Disaggregation of Revenue [Line Items]
Alternative revenue and other	4	4
Alternative revenue and other | Regulated Electric
Disaggregation of Revenue [Line Items]
Alternative revenue and other	3	3
Alternative revenue and other | Regulated Natural Gas
Disaggregation of Revenue [Line Items]
Alternative revenue and other	$ 1	$ 1

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Income Taxes (Details)		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent		21.00%	21.00%
Effective Income Tax Rate Reconciliation, State and Local Income Taxes, Percent		6.20%	6.20%
Effective Income Tax Rate Reconciliation, Other Regulatory Items, Percent	[1]	(3.50%)	(3.70%)
Effective Income Tax Rate Reconciliation, Other Adjustments, Percent		(1.30%)	(0.50%)
Effective Income Tax Rate Reconciliation, Percent		22.40%	23.00%

[1] Regulatory differences for income tax primarily relate to the credit of excess deferred taxes to customers through the average rate assumption method. Income tax benefits associated with the credit of excess deferred taxes are offset by corresponding revenue reductions.

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Fair Value of Financial Assets and Liabilities - Interest Rate Derivatives (Details) - Natural Gas Commodity - Other Derivative Instruments - Fair Value, Recurring [Member] - USD ($) $ in Millions		Mar. 31, 2023	Dec. 31, 2022
Derivative [Line Items]
Derivative Asset, Net		$ 0	$ 2	[1]
Other Current Assets
Derivative [Line Items]
Derivative Asset, Gross	[1]		2
Netting	[1],[2]		0
Other Current Assets | Level 1
Derivative [Line Items]
Derivative Asset, Gross	[1]		0
Other Current Assets | Level 2
Derivative [Line Items]
Derivative Asset, Gross	[1]		2
Other Current Assets | Level 3
Derivative [Line Items]
Derivative Asset, Gross	[1]		$ 0

[1] $2 million included in prepayments and other current assets and $1 million included in other current liabilities at Dec. 31, 2022 on the consolidated balance sheet.

[2] NSP-Wisconsin nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

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Fair Value of Financial Assets and Liabilities - Commodity Derivatives (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Cash Flow Hedges
Derivative [Line Items]
Derivative Instruments in Hedges, at Fair Value, Net	$ 0
Natural Gas Commodity | Fair Value, Recurring [Member] | Other Derivative Instruments
Derivative [Line Items]
Derivative Asset, Net	$ 0	$ 2	[1]
Natural Gas Commodity | Fair Value, Recurring [Member] | Other Derivative Instruments | Prepaid Expenses and Other Current Assets
Derivative [Line Items]
Derivative Asset, Net		$ 2

[1] $2 million included in prepayments and other current assets and $1 million included in other current liabilities at Dec. 31, 2022 on the consolidated balance sheet.

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Fair Value of Financial Assets and Liabilities - Impact of Derivative Activities on Income (Details) $ in Millions	3 Months Ended
	Mar. 31, 2023 USD ($)
Other Derivative Instruments | Natural Gas Commodity
Derivative Instruments, Gain (Loss) [Line Items]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities	$ 1

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Fair Value of Financial Assets and Liabilities - Recurring Fair Value Measurements (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Dec. 31, 2022
Derivatives, Fair Value [Line Items]
Prepayments and other		$ 8	$ 11
Other Derivative Instruments | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Pre-tax fair value gains (losses) recognized during the period in regulatory (assets) and liabilities		1
Derivative, Gain (Loss) on Derivative, Net		2
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset, Net		0	2	[1]
Derivative Liability		$ 0	1	[1]
Derivative Liability, Not Subject to Master Netting Arrangement	[1]		1
Derivative Liability, Fair Value, Gross Asset and Right to Reclaim Cash, Offset	[1],[2]		0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Natural Gas Commodity | Level 1
Derivatives, Fair Value [Line Items]
Derivative Liability, Not Subject to Master Netting Arrangement	[1]		0
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Natural Gas Commodity | Level 2
Derivatives, Fair Value [Line Items]
Derivative Liability, Not Subject to Master Netting Arrangement	[1]		1
Fair Value Measured on a Recurring Basis | Other Derivative Instruments | Natural Gas Commodity | Level 3
Derivatives, Fair Value [Line Items]
Derivative Liability, Not Subject to Master Netting Arrangement	[1]		0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative Asset, Gross	[1]		2
Netting	[1],[2]		0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Natural Gas Commodity | Level 1
Derivatives, Fair Value [Line Items]
Derivative Asset, Gross	[1]		0
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Natural Gas Commodity | Level 2
Derivatives, Fair Value [Line Items]
Derivative Asset, Gross	[1]		2
Fair Value Measured on a Recurring Basis | Other Current Assets | Other Derivative Instruments | Natural Gas Commodity | Level 3
Derivatives, Fair Value [Line Items]
Derivative Asset, Gross	[1]		0
Fair Value Measured on a Recurring Basis | Other Current Liabilities | Other Derivative Instruments | Natural Gas Commodity
Derivatives, Fair Value [Line Items]
Derivative Liability			$ 1

[1] $2 million included in prepayments and other current assets and $1 million included in other current liabilities at Dec. 31, 2022 on the consolidated balance sheet.

[2] NSP-Wisconsin nets derivative instruments and related collateral on its consolidated balance sheets when supported by a legally enforceable master netting agreement. Counterparty netting excludes settlement receivables and payables and non-derivative amounts that may be subject to the same master netting agreements.

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Fair Value of Financial Assets and Liabilities - Fair Value of Long-Term Debt (Details) - USD ($) $ in Millions	Mar. 31, 2023	Dec. 31, 2022
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Carrying Amount	$ 1,087	$ 1,086
Level 2
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-term Debt, Fair Value	$ 1,006	$ 980

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Benefit Plans and Other Postretirement Benefits (Details) - USD ($) $ in Millions		1 Months Ended	3 Months Ended
		Jan. 31, 2023	Mar. 31, 2023	Mar. 31, 2022
Components of Net Periodic Benefit Cost [Abstract]
Operating and maintenance expenses			$ 58	$ 53
Pension Plan [Member]
Components of Net Periodic Benefit Cost [Abstract]
Service cost			1	1
Interest cost (a)	[1]		2	1
Expected return on plan assets (a)	[1]		(2)	(2)
Amortization of net loss (a)	[1]		0	1
Net benefit cost recognized for financial reporting			$ 1	$ 1
Contributions to pension plans		$ 4
Pension Plan [Member] | Parent Company [Member]
Components of Net Periodic Benefit Cost [Abstract]
Contributions to pension plans		$ 50

[1] The components of net periodic cost other than the service cost component are included in the line item “Other income, net” in the consolidated statements of income or capitalized on the consolidated balance sheets as a regulatory asset.

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Commitments and Contingencies Gas Trading Litigation (Details)	Mar. 31, 2023
Gas Trading Litigation
Loss Contingencies [Line Items]
Loss Contingency, Pending Claims, Number	1

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MISO ROE Complaints (Details) - Federal Energy Regulatory Commission (FERC) - FERC Proceeding, MISO ROE Complaint - NSP Minnesota and NSP Wisconsin [Member] [Member]	1 Months Ended
	Feb. 28, 2015	Nov. 30, 2013
Rate Matters [Abstract]
Public Utilities, Base Return On Equity Charged To Customers Through Transmission Formula Rates	12.38%	12.38%
Public Utilities, ROE Applicable To Transmission Formula Rates In The MISO Region, Recommended By Third Parties	8.67%	9.15%

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Commitments and Contingencies (Details) - Enviromental Requirements $ in Millions	Mar. 31, 2023 USD ($)
Loss Contingencies [Line Items]
Liability for estimated cost to comply with regulation	$ 5.0
Gain Contingencies [Line Items]
Liability for estimated cost to comply with regulation	$ 5.0
Plants required for improvements	2
Public Utilities, General Disclosures [Line Items]
Plants required for improvements	2
Other MGP, Landfill, or Disposal Sites [Domain]
Loss Contingencies [Line Items]
Number of identified MGP sites under current investigation and/or remediation	1
Gain Contingencies [Line Items]
Number of identified MGP sites under current investigation and/or remediation	1

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Segment Information (Details) - USD ($) $ in Millions		3 Months Ended
		Mar. 31, 2023	Mar. 31, 2022
Segment Reporting Information [Line Items]
Net income		$ 45	$ 47
Regulated and Unregulated Operating Revenue		331	328
Affiliate Revenue		50	47
Natural gas		77	78
Total revenues
Segment Reporting Information [Line Items]
Regulated and Unregulated Operating Revenue	[1]	331	328
Regulated Electric
Segment Reporting Information [Line Items]
Net income		33	32
Regulated Electric | Total revenues
Segment Reporting Information [Line Items]
Regulated Operating Revenue, Electric	[1]	254	250
Regulated Natural Gas
Segment Reporting Information [Line Items]
Net income		11	15
Revenues Including Intersegment Revenues		77	78
All Other
Segment Reporting Information [Line Items]
Net income		$ 1	$ 0

[1] Total revenues include $50 million and $47 million of affiliate electric revenue for the three months ended March 31, 2023 and 2022, respectively.