CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Current assets:
Cash and cash equivalents (includes $119 and $358 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	$ 29,928	$ 24,310
Accounts receivable, net of allowances of $2,454 and $—, respectively (includes $17 and $435 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	31,113	32,013
Restricted cash - current (includes $906 and $972 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	1,077	972
Fuel tax credits receivable	3,264	5,639
Contract assets	12,646	11,075
Parts inventory	12,082	10,294
Prepaid expense and other current assets (includes $1,100 and $144 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	10,984	18,363
Total current assets	122,785	117,188
Property, plant, and equipment, net (includes $30,931 and $25,428 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	484,351	458,258
Investment in other entities	227,545	223,594
Other long-term assets	24,182	23,483
Restricted cash - non-current (includes $2,633 and $2,315 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	3,278	3,946
Goodwill	54,608	54,608
Total assets	916,749	881,077
Current liabilities:
Fuel tax credits payable	3,069	4,422
Accrued payroll (includes $39 and $45 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	8,611	9,580
Accrued and payable capital expenditures	10,014	23,238
Accrued environmental credit rebates	4,593	5,391
Accrued expenses and other current liabilities (includes $1,148 and $974 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	14,880	14,717
Contract liabilities	8,378	9,276
OPAL Term Loan - current portion	9,349	10,865
Sunoma Loan - current portion (includes $1,861 and $1,756 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	1,861	1,756
Total current liabilities	83,461	103,596
OPAL Term Loan, net of debt issuance costs	313,324	266,630
Sunoma Loan, net of debt issuance costs (includes $17,071 and $18,373 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	17,071	18,373
Operating lease liabilities - non-current portion	11,940	12,155
Other long-term liabilities (includes $1,307 and $2,495 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	8,157	15,291
Total liabilities	433,953	416,045
Commitments and contingencies Note 12
Stockholders' equity (deficit)
Retained earnings (accumulated deficit)	19,089	(137,004)
Accumulated other comprehensive (loss) income	(12)	152
Class A common stock in treasury, at cost; 1,635,783 at September 30, 2025 and December 31, 2024	(11,614)	(11,614)
Total Stockholders' equity (deficit) attributable to the Company	7,480	(148,449)
Non-redeemable non-controlling interests	2,788	618
Total Stockholders' equity (deficit)	10,268	(147,831)
Total liabilities, Redeemable preferred non-controlling interests, Redeemable non-controlling interests and Stockholders' equity (deficit)	916,749	881,077
Redeemable preferred non-controlling interests
Current liabilities:
Redeemable non-controlling interests	130,000	130,000
Redeemable non-controlling interests
Current liabilities:
Redeemable non-controlling interests	342,528	482,863
Class A Common Stock
Stockholders' equity (deficit)
Common stock	3	3
Class B Common Stock
Stockholders' equity (deficit)
Common stock	12	7
Class C common stock
Stockholders' equity (deficit)
Common stock	0	0
Class D Common Stock
Stockholders' equity (deficit)
Common stock	2	7
Nonrelated Party
Current assets:
Accounts receivable, net of allowances of $2,454 and $—, respectively (includes $17 and $435 at September 30, 2025 and December 31, 2024, respectively, related to consolidated VIEs)	31,113	32,013
Current liabilities:
Accounts payable	15,281	16,419
Related Party
Current assets:
Accounts receivable, related party	21,691	14,522
Current liabilities:
Accounts payable	$ 7,425	$ 7,932