Regulatory Matters

12 Months Ended

Dec. 31, 2019

Regulatory Assets and Liabilities Disclosure [Abstract]

Regulatory Matters

REGULATORY MATTERS

Regulation

DTE Electric and DTE Gas are subject to the regulatory jurisdiction of the MPSC, which issues orders pertaining to rates, recovery of certain costs, including the costs of generating facilities and regulatory assets, conditions of service, accounting, and operating-related matters. DTE Electric is also regulated by the FERC with respect to financing authorization and wholesale electric activities. Regulation results in differences in the application of generally accepted accounting principles between regulated and non-regulated businesses.

The Registrants are unable to predict the outcome of the unresolved regulatory matters discussed herein. Resolution of these matters is dependent upon future MPSC orders and appeals, which may materially impact the Consolidated Financial Statements of the Registrants.

Regulatory Assets and Liabilities

DTE Electric and DTE Gas are required to record Regulatory assets and liabilities for certain transactions that would have been treated as revenue or expense in non-regulated businesses. Continued applicability of regulatory accounting treatment requires that rates be designed to recover specific costs of providing regulated services and be charged to and collected from customers. Future regulatory changes could result in the discontinuance of this accounting treatment for Regulatory assets and liabilities for some or all of the Registrants' businesses and may require the write-off of the portion of any Regulatory asset or liability that was no longer probable of recovery through regulated rates. Management believes that currently available facts support the continued use of Regulatory assets and liabilities and that all Regulatory assets and liabilities are recoverable or refundable in the current regulatory environment.

The following are balances and a brief description of the Registrants' Regulatory assets and liabilities at December 31:

	DTE Energy						DTE Electric
	2019			2018			2019			2018
Assets	(In millions)
Recoverable pension and other postretirement costs
Pension	$	1,983		$	1,961		$	1,497		$	1,476
Other postretirement costs	201			213			131			121
Fermi 2 asset retirement obligation	669			778			669			778
Recoverable undepreciated costs on retiring plants	657			630			657			630
Recoverable Michigan income taxes	189			201			152			161
Deferred environmental costs	66			69			—			—
Recoverable income taxes related to AFUDC equity	56			51			47			41
Unamortized loss on reacquired debt	56			60			40			43
Customer360 deferred costs	55			42			55			42
Energy Waste Reduction incentive	54			49			43			39
Nuclear Performance Evaluation and Review Committee Tracker	48			43			48			43
Enhanced Tree Trimming Program deferred costs	43			—			43			—
Other recoverable income taxes	20			23			20			23
Non-service pension and other postretirement costs	15			10			—			—
Transitional Reconciliation Mechanism	10			21			10			21
Accrued PSCR/GCR revenue	3			116			3			116
Removal costs asset	—			407			—			407
Other	51			47			38			36
	4,176			4,721			3,453			3,977
Less amount included in Current Assets	(5		)	(153		)	(5		)	(148		)
	$	4,171		$	4,568		$	3,448		$	3,829

	DTE Energy						DTE Electric
	2019			2018			2019			2018
Liabilities	(In millions)
Refundable federal income taxes	$	2,359		$	2,410		$	1,911		$	1,958
Removal costs liability	700			253			483			—
Negative other postretirement offset	93			101			69			79
Renewable energy	54			86			54			86
Non-service pension and other postretirement costs	46			22			21			11
Accrued PSCR/GCR refund	23			—			—			—
TCJA rate reduction liability	1			118			—			93
Other	53			58			48			42
	3,329			3,048			2,586			2,269
Less amount included in Current Liabilities	(65		)	(126		)	(40		)	(98		)
	$	3,264		$	2,922		$	2,546		$	2,171

As noted below, certain Regulatory assets for which costs have been incurred have been included (or are expected to be included, for costs incurred subsequent to the most recently approved rate case) in DTE Electric's or DTE Gas' rate base, thereby providing a return on invested costs (except as noted). Certain other regulatory assets are not included in rate base but accrue recoverable carrying charges until surcharges to collect the assets are billed. Certain Regulatory assets do not result from cash expenditures and therefore do not represent investments included in rate base or have offsetting liabilities that reduce rate base.

ASSETS

• Recoverable pension and other postretirement costs — Accounting standards for pension and other postretirement benefit costs require, among other things, the recognition in Other comprehensive income of the actuarial gains or losses and the prior service costs that arise during the period but that are not immediately recognized as components of net periodic benefit costs. DTE Electric and DTE Gas record the impact of actuarial gains or losses and prior service costs as a Regulatory asset since the traditional rate setting process allows for the recovery of pension and other postretirement costs. The asset will reverse as the deferred items are amortized and recognized as components of net periodic benefit costs.^(a) 

• Fermi 2 asset retirement obligation — This obligation is for Fermi 2 decommissioning costs. The asset captures the timing differences between expense recognition and current recovery in rates and will reverse over the remaining life of the related plant.^(a) 

• Recoverable undepreciated costs on retiring plants — Deferral of estimated remaining balances associated with coal power plants expected to be retired by 2023.

• Recoverable Michigan income taxes — The State of Michigan enacted a corporate income tax resulting in the establishment of state deferred tax liabilities for DTE Energy's utilities.  Offsetting Regulatory assets were also recorded as the impacts of the deferred tax liabilities will be reflected in rates as the related taxable temporary differences reverse and flow through current income tax expense.

• Deferred environmental costs — The MPSC approved the deferral of investigation and remediation costs associated with DTE Gas' former MGP sites. Amortization of deferred costs is over a ten-year period beginning in the year after costs were incurred, with recovery (net of any insurance proceeds) through base rate filings.^(a) 

• Recoverable income taxes related to AFUDC equity — Accounting standards for income taxes require recognition of a deferred tax liability for the equity component of AFUDC.  A regulatory asset is required for the future increase in taxes payable related to the equity component of AFUDC that will be recovered from customers through future rates over the remaining life of the related plant.

• Unamortized loss on reacquired debt — The unamortized discount, premium, and expense related to debt redeemed with a refinancing are deferred, amortized, and recovered over the life of the replacement issue.

• Customer360 deferred costs — The MPSC approved the deferral and amortization of certain costs associated with implementing Customer360, an integrated software application that enables improved interface among customer service, billing, meter reading, credit and collections, device management, account management, and retail access. Amortization of deferred costs over a 15-year amortization period began after the billing system was put into operation during the second quarter of 2017.

• Energy Waste Reduction incentive — DTE Electric and DTE Gas operate MPSC approved energy waste reduction programs designed to reduce overall energy usage by their customers. The utilities are eligible to earn an incentive by exceeding statutory savings targets. The utilities have consistently exceeded the savings targets and recognize the incentive as a regulatory asset in the period earned.^(a) 

• Nuclear Performance Evaluation and Review Committee Tracker — Deferral and amortization of certain costs associated with oversight and review of DTE Electric's nuclear power generation program, including safety and regulatory compliance, nuclear leadership, nuclear facilities, as well as operation and financial performance, pursuant to the MPSC authorization. The approved five-year amortization period began January 1, 2018, with recovery through base rate filings.

• Enhanced Tree Trimming Program deferred costs — The MPSC approved the deferral of costs for the first three years of a tree trimming surge, aimed at reducing the number and duration of customer interruptions.  The MPSC will review the surge program and amortization of deferred costs in future rate filings.

• Other recoverable income taxes — Income taxes receivable from DTE Electric's customers representing the difference in property-related deferred income taxes and amounts previously reflected in DTE Electric's rates. This asset will reverse over the remaining life of the related plant.

• Non-service pension and other postretirement costs — Upon adoption of ASU 2017-07 on January 1, 2018, certain non-service costs are no longer capitalized into Property, Plant & Equipment. Such costs may be recorded to regulatory assets for ratemaking purposes and recovered as amortization expense based on the composite depreciation rate for plant-in-service.

• Transitional Reconciliation Mechanism — The MPSC approved the recovery of the deferred net incremental revenue requirement associated with the transition of PLD customers to DTE Electric's distribution system, effective July 1, 2014. Annual reconciliations are filed and surcharges are implemented to recover approved amounts.

• Accrued PSCR/GCR revenue — Receivable for the temporary under-recovery of and carrying costs on fuel and purchased power costs incurred by DTE Electric which are recoverable through the PSCR mechanism and temporary under-recovery of and carrying costs on gas costs incurred by DTE Gas which are recoverable through the GCR mechanism.

• Removal costs asset — Receivable for the recovery of asset removal expenditures in excess of amounts collected from customers.^(a) Cost of removal is included within depreciation rates approved by the MPSC.  In connection with DTE Electric's recent rate order in 2019 which approved an updated depreciation study, DTE Electric re-measured the amount of historical depreciation expense that had been allocated between accumulated depreciation and cost of removal. The reallocation was performed following a settlement with the MPSC in which DTE Electric agreed to maintain specific, individual reserve accounts for the cost of removal for certain retiring plants. Based upon the reallocation, it was determined that the amounts collected for asset removal expenditures, as a component of depreciation, have exceeded actual asset removal expenditures.  Accordingly, DTE Electric reallocated amounts from accumulated depreciation to the removal cost regulatory balance resulting in a net Removal costs liability as of December 31, 2019. 

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(a) Regulatory assets not earning a return or accruing carrying charges.

LIABILITIES

• Refundable federal income taxes — DTE Electric and DTE Gas' remeasurement of deferred taxes due to the enactment of the TCJA, which reflects the net impact of the tax rate change on cumulative temporary differences expected to reverse after the effective date of January 1, 2018. Refer to "2017 Tax Reform" section below for additional information.

• Removal costs liability — The amount collected from customers for the funding of future asset removal activities. For 2019, the liability includes amounts previously reflected within the Removal costs asset for DTE Electric, as noted above.

• Negative other postretirement offset — DTE Electric and DTE Gas' negative other postretirement costs are not included as a reduction to their authorized rates; therefore, DTE Electric and DTE Gas are accruing a Regulatory liability to eliminate the impact on earnings of the negative other postretirement expense accrual. The Regulatory liabilities will reverse to the extent DTE Electric and DTE Gas' other postretirement expense is positive in future years.

• Renewable energy — Amounts collected in rates in excess of renewable energy expenditures.

• Non-service pension and other postretirement costs — Upon adoption of ASU 2017-07 on January 1, 2018, certain non-service cost activity is no longer credited to Property, Plant & Equipment. Such costs may be recorded to regulatory liabilities for ratemaking purposes and refunded through credits to amortization expense based on the composite depreciation rate for plant-in-service.

• Accrued PSCR/GCR refund - Liability for the temporary over-recovery of and a return on power supply costs and transmission costs incurred by DTE Electric which are recoverable through the PSCR mechanism and temporary over-recovery of and a return on gas costs incurred by DTE Gas which are recoverable through the GCR mechanism.

• TCJA rate reduction liability — Due to the change in the corporate Federal income tax rate from 35% to 21%, DTE Electric and DTE Gas reduced rates charged to customers during 2018. A regulatory liability equal to the difference between revenues billed based on a 35% rate, and revenues based on a 21% rate, was accrued for the period January 1, 2018 through the date the lower rates were implemented. The refund of the liability occurred from January 1, 2019 through June 30, 2019.

2018 Electric Rate Case Filing

DTE Electric filed a rate case with the MPSC on July 6, 2018 requesting an increase in base rates of $328 million based on a projected twelve-month period ending April 30, 2020. The requested increase in base rates was primarily due to an increase in net plant resulting from infrastructure investments, depreciation expense, as requested in the 2016 DTE Electric Depreciation Case Filing, and reliability improvement projects. The rate filing also requested an increase in return on equity from 10.0% to 10.5% and included projected changes in sales, operation and maintenance expenses, and working capital. In addition, the rate filing requested an Infrastructure Recovery Mechanism to recover the incremental revenue requirement associated with certain distribution, fossil generation, and nuclear generation capital expenditures through 2022. Finally, as noted in the 2017 Tax Reform section below, DTE Electric proposed an amortization schedule for Calculation C in this filing. On February 1, 2019 DTE Electric reduced its initial requested increase in base rates to $248.6 million, primarily reflecting the reduction in requested depreciation expense resulting from the MPSC's approval of new depreciation rates. On May 2, 2019, the MPSC issued an order approving an annual revenue increase of $125 million for services rendered on or after May 9, 2019. The MPSC authorized a return on equity of 10.0%. In addition, the order approved the proposed amortization schedule for Calculation C but denied the requested Infrastructure Recovery Mechanism.

2019 Electric Rate Case Filing

DTE Electric filed a rate case with the MPSC on July 8, 2019 requesting an increase in base rates of $351 million based on a projected twelve-month period ending April 30, 2021. The requested increase in base rates is primarily due to an increase in net plant resulting from infrastructure and generation investments. The rate filing also requests an increase in return on equity from 10.0% to 10.5% and includes projected changes in sales and operating and maintenance expenses. A final MPSC order in this case is expected by May 2020.

2016 DTE Electric Depreciation Case Filing

DTE Electric filed a depreciation case with the MPSC on November 1, 2016 requesting an increase in depreciation rates for plant in service balances as of December 31, 2015. The MPSC issued an order on December 6, 2018 authorizing DTE Electric to increase its composite depreciation rate from 3.06% to 3.72%. The new rates are effective for service rendered on or after May 9, 2019, per the final order in DTE Electric's 2018 rate case issued on May 2, 2019.

2017 Tax Reform

On December 27, 2017, the MPSC issued an order to consider changes in the rates of all Michigan rate-regulated utilities to reflect the effects of the federal TCJA. On January 19, 2018, DTE Electric and DTE Gas filed information with the MPSC regarding the potential change in revenue requirements due to the TCJA effective January 1, 2018 and outlined their recommended method to flow the current and deferred tax benefits of those impacts to ratepayers.

On February 22, 2018, the MPSC issued an order in this case requiring utilities, including DTE Electric and DTE Gas, to follow a 3-step approach of credits and calculations. In 2018, MPSC orders for the first two steps, Credit A and Credit B, were issued for DTE Electric and DTE Gas. The third step is to perform Calculation C to address all remaining issues relative to the new tax law, which is primarily the remeasurement of deferred taxes and how the amounts deferred as Regulatory liabilities will flow to ratepayers. DTE Gas filed its Calculation C case on November 16, 2018 to reduce the annual revenue requirement by $12 million related to the amortization of deferred tax remeasurement. On August 20, 2019, the MPSC issued an order in this case approving a $13 million reduction to DTE Gas' annual revenue requirement. This reduction in revenue will be offset by a corresponding reduction in income tax expenses with the Consolidated Statement of Operations. DTE Electric proposed an amortization schedule for Calculation C in its general rate case filed July 6, 2018, which was approved by the MPSC in the May 2, 2019 rate order.

2019 Gas Rate Case Filing

DTE Gas filed a rate case with the MPSC on November 25, 2019 requesting an increase in base rates of $204 million based on a projected twelve-month period ending September 30, 2021.  The requested increase in base rates is primarily due to an increase in net plant resulting from infrastructure investments and operating and maintenance expenses.  The rate filing also requests an increase in return on equity from 10.0% to 10.5% and includes projected changes in sales and working capital.  A final MPSC order in this case is expected by September 2020.