Income Taxes (Tables)

12 Months Ended

Dec. 31, 2025

Income Tax Disclosure [Abstract]

Schedule of Income Tax Provision From Continuing Operations

The income tax provision consisted of the following amounts:

	Year Ended December 31,
	2025		2024		2023
	(In millions)
Current
U.S. Federal	$	(1)	$	1	$	(13)
State	5		4		(2)
Total — current	4		5		(15)
Deferred
U.S. Federal	$	42	$	22	$	13
State	10		3		—
Total — deferred	52		25		13
Total income tax expense (benefit)	$	56	$	30	$	(2)

Schedule of Reconciliation of the U.S. Federal Statutory Rate to the Company's Effective Rate

The following table is a reconciliation of the U.S. federal statutory rate of 21% to the Company’s effective rate in accordance with the guidance in ASU 2023-09:

	Year Ended December 31,					Year Ended December 31,
	2025					2024
	(In millions, except percentages)					(In millions, except percentages)
Loss Before Income Taxes	$	(175)				$	(33)
Tax at 21%	(37)			21.1	%	(7)			21.0	%
State taxes, net of federal benefit (a)	12			(6.8)	%	6			(18.2)	%
Tax credits	(1)			0.6	%	(4)			12.1	%
Nontaxable/nondeductible items:
HLBV impact	84			(48.0)	%	32			(96.9)	%
Tax credit sales, net	(3)			1.7	%	—			—	%
Employee share-based payments	—			—	%	2			(6.0)	%
Other	1			(0.6)	%	1			(2.9)	%
Income tax expense	$	56		(32.0)	%	$	30		(90.9)	%
Effective income tax rate	(32.0)		%			(90.9)		%

(a) State taxes in California made up the majority of the tax effect in this category.

The following table is a reconciliation of the U.S. federal statutory rate of 21% to the Company’s effective rate in accordance with the guidance prior to the adoption of ASU 2023-09:

	Year Ended December 31, 2023
	(In millions, except percentages)
Loss Before Income Taxes	$	(16)
Tax at 21%	(3)
State taxes, net of federal benefit	(2)
Impact of non-taxable partnership earnings	21
Valuation allowance	3
Investment tax credits	(1)
Production tax credits (a)	(16)
Rate change	1
State taxes assessed at subsidiaries	(3)
Other	(2)
Income tax benefit	$	(2)
Effective income tax rate	12.5		%

(a) On December 6, 2023, the Company executed an agreement with a third party to sell the PTCs generated by the Alta X and Alta XI wind facilities, which resulted in a $14 million income tax benefit (reduction to income tax expense) during the year ended December 31, 2023.

Schedule of Company's Deferred Tax Assets and Liabilities

The temporary differences, which gave rise to the Company’s deferred tax balances consisted of the following:

	As of December 31,
	2025		2024
	(In millions)
Deferred tax liabilities:
Investment in projects	$	245	$	191
Total deferred tax liabilities	245		191
Deferred tax assets:
Interest expense disallowance carryforward - Investment in Projects	$	24	$	18
Production tax credits	12		16
Investment tax credits	6		7
Investment tax credits subject to transferability	304		—
U.S. Federal net operating loss carryforwards	44		58
State net operating loss carryforwards	7		7
Total deferred tax assets	397		106
Valuation allowance	(25)		(4)
Total deferred tax assets, net of valuation allowance	372		102
Net deferred non-current tax asset (liability)	$	127	$	(89)

Schedule of Unrecognized Tax Benefits

The following table summarizes the Company’s unrecognized tax benefits activity:

(In millions)
Balance as of December 31, 2024	$	—
Increase due to prior year positions	19
Balance as of December 31, 2025	$	19