v3.26.1
Risk Management, Derivative Instruments and Hedging Activities (Tables)
 6 Months Ended
Jun. 30, 2026
Derivative Instruments and Hedging Activities Disclosure [Abstract]  
Schedule of Net Notional Volumes of Open Commodity Derivatives and Interest Rate Derivatives The net notional volumes of commodity derivatives were:
June 30,
2026 (a)
December 31,
2025 (a)
Power (MWh)(87,190,322)(59,634,723)
Natural gas (MMBtu)311,022,216 169,209,022 
Emission allowances (tons)158,000 — 
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(a)The volumes may be different than the contractual volumes, as the probability that option contracts will be exercised is considered in the volumes displayed.
Open interest rate derivatives range in maturity through 2029. The net notional volumes of open interest rate derivatives were:
June 30,
2026		December 31,
2025
Interest rate (in millions)
$990 $990 
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value
Balance Sheets Presentation. The fair value of derivative instruments presented within assets and liabilities on the Consolidated Balance Sheets were:
June 30, 2026December 31, 2025
AssetsLiabilitiesAssetsLiabilities
Commodity contracts$130 $572 $56 $97 
Interest rate contracts1 1 — 4 
Total current derivative instruments131 573 56 101 
Commodity contracts7 149 4 59 
Interest rate contracts2 1 — 8 
Total non-current derivative instruments$9 $150 $4 $67 
Schedule of Effect of Netting, Offsetting Assets
The net amounts of “Derivative instruments” presented as assets and liabilities on the Consolidated Balance Sheets considering the effect of permitted netting and where cash collateral is pledged in accordance with the underlying agreement were:
Gross Derivative InstrumentsEligible for OffsetNet Derivative InstrumentsCollateral (Posted) ReceivedNet Amounts
June 30, 2026
Assets$1,033 $(851)$182 $(42)$140 
Liabilities1,695 (851)844 (121)723 
December 31, 2025
Assets$456 $(396)$60 $— $60 
Liabilities608 (396)212 (44)168 
Schedule of Effect of Netting, Offsetting Liabilities
The net amounts of “Derivative instruments” presented as assets and liabilities on the Consolidated Balance Sheets considering the effect of permitted netting and where cash collateral is pledged in accordance with the underlying agreement were:
Gross Derivative InstrumentsEligible for OffsetNet Derivative InstrumentsCollateral (Posted) ReceivedNet Amounts
June 30, 2026
Assets$1,033 $(851)$182 $(42)$140 
Liabilities1,695 (851)844 (121)723 
December 31, 2025
Assets$456 $(396)$60 $— $60 
Liabilities608 (396)212 (44)168 
Schedule of Derivative Instruments, Gain (Loss) The location and pre-tax effect of “Derivative instruments” presented on the Consolidated Statements of Operations for the periods were:
 Three Months Ended June 30,Six Months Ended June 30,
2026202520262025
Realized gain (loss) on commodity contracts
Energy revenues (a)
$65 $43 $(262)$16 
Fuel and energy purchases (a)
(26)(5)26 19 
Unrealized gain (loss) on commodity contracts
Operating revenues (b)
(212)176 (324)(65)
Energy expenses (b)
1 (84)(41)(25)
Realized and unrealized gain (loss) on interest rate contracts
Interest expense and other finance charges 9 — 11 (13)
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(a)Does not include those derivative instruments that settle through physical delivery.
(b)Presented as “Unrealized gain (loss) on derivative instruments” on the Consolidated Statements of Operations.