OPAL Fuels (OPAL) 10-Q 10 May 24 2024 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2024	May 09, 2024
Document Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2024
Document Transition Report	false
Entity File Number	001-40272
Entity Registrant Name	OPAL FUELS INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	98-1578357
Entity Address, Address Line One	One North Lexington Avenue
Entity Address, Address Line Two	Suite 1450
Entity Address, City or Town	White Plains
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10601
City Area Code	914
Local Phone Number	705-4000
Title of 12(b) Security	Class A Common Stock, par value $0.0001 per share
Trading Symbol	OPAL
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Central Index Key	0001842279
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Current Fiscal Year End Date	--12-31
Class A common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		28,386,505
Class B common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		71,500,000
Class D common stock
Document Information [Line Items]
Entity Common Stock, Shares Outstanding		72,899,037

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents (includes $1,160 and $166 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	$ 28,207	$ 38,348
Accounts receivable, net (includes $334 and $33 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	22,805	27,623
Restricted cash - current (includes $1,012 and $4,395 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	1,012	4,395
Short term investments	5,975	9,875
Fuel tax credits receivable	4,212	5,345
Contract assets	8,997	6,790
Parts inventory (includes $29 and $29 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	11,135	10,191
Environmental credits held for sale	1,534	172
Prepaid expense and other current assets (includes $113 and $107 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	6,373	6,005
Derivative financial assets, current portion	537	633
Total current assets	105,699	128,073
Capital spares	3,638	3,468
Property, plant, and equipment, net (includes $26,254 and $26,626 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	359,369	339,493
Operating lease right-of-use assets	12,137	12,301
Investment in other entities	206,014	207,099
Note receivable - variable fee component	2,369	2,302
Other long-term assets	1,651	1,162
Intangible assets, net	1,537	1,604
Restricted cash - non-current (includes $1,957 and $1,850 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	3,477	4,499
Goodwill	54,608	54,608
Total assets	750,499	754,609
Current liabilities:
Fuel tax credits payable	4,551	4,558
Accrued payroll	10,422	9,023
Accrued capital expenses	10,743	15,128
Accrued expenses and other current liabilities (includes $861 and $647 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	16,792	14,245
Contract liabilities	7,785	6,314
OPAL Term Loan, current portion	1,866	0
Sunoma Loan, current portion (includes $1,652 and $1,608 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	1,652	1,608
Operating lease liabilities - current portion	656	638
Other current liabilities (includes $94 and $92 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	94	92
Asset retirement obligation, current portion	1,812	1,812
Total current liabilities	75,354	74,343
Asset retirement obligation, non-current portion	5,068	4,916
OPAL Term Loan, net of debt issuance costs	175,161	176,532
Sunoma Loan, net of debt issuance costs (includes $19,609 and $20,010 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	19,609	20,010
Operating lease liabilities - non-current portion	11,646	11,824
Earn out liabilities	1,497	1,900
Other long-term liabilities (includes $1,297 and $211 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)	8,637	7,599
Total liabilities	296,972	297,124
Commitments and contingencies
Stockholders' deficit
Additional paid-in capital	0	0
Accumulated deficit	(370,832)	(467,195)
Accumulated other comprehensive income (loss)	42	(15)
Class A common stock in treasury, at cost; 1,635,783 shares at March 31, 2024 and December 31, 2023	(11,614)	(11,614)
Total Stockholders' deficit attributable to the Company	(382,387)	(478,807)
Non-redeemable non-controlling interests	724	955
Total Stockholders' deficit	(381,663)	(477,852)
Total liabilities, Redeemable preferred non-controlling interests, Redeemable non-controlling interests and Stockholders' deficit	750,499	754,609
Nonrelated Party
Current liabilities:
Accounts payable	10,815	13,901
Related Party
Current assets:
Accounts receivable, related party	14,912	18,696
Current liabilities:
Accounts payable	8,166	7,024
Redeemable preferred non-controlling interests
Current liabilities:
Redeemable non-controlling interests	130,000	132,617
Redeemable non-controlling interests
Current liabilities:
Redeemable non-controlling interests	705,190	802,720
Class A common stock
Stockholders' deficit
Common stock	3	3
Class B common stock
Stockholders' deficit
Common stock	7	0
Common Class C
Stockholders' deficit
Common stock	0	0
Class D common stock
Stockholders' deficit
Common stock	$ 7	$ 14

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Cash and cash equivalents	$ 28,207	$ 38,348
Accounts receivable, net	22,805	27,623
Restricted cash - current	1,012	4,395
Parts inventory	11,135	10,191
Prepaid expenses and other current assets	6,373	6,005
Property, plant and equipment, net	359,369	339,493
Restricted cash, non-current	3,477	4,499
Accrued expenses and other current liabilities	16,792	14,245
Sunoma Loan- current portion	1,652	1,608
Other current liabilities	94	92
Sunoma Loan, net of debt issuance costs	19,609	20,010
Other long-term liabilities	$ 8,637	$ 7,599
Class A common stock, in treasury, at cost (in shares)	1,635,783	1,635,783
Related Party
Accounts payable	$ 8,166	$ 7,024
Primary Beneficiary
Cash and cash equivalents	1,160	166
Accounts receivable, net	334	33
Restricted cash - current	1,012	4,395
Parts inventory	29	29
Prepaid expenses and other current assets	113	107
Property, plant and equipment, net	26,254	26,626
Restricted cash, non-current	1,957	1,850
Accounts payable	11	744
Accrued expenses and other current liabilities	861	647
Sunoma Loan- current portion	1,652	1,608
Other current liabilities	94	92
Sunoma Loan, net of debt issuance costs	19,609	20,010
Other long-term liabilities	1,297	211
Primary Beneficiary | Related Party
Accounts payable	$ 802	$ 1,046
Class A common stock
Common stock, par value (in dollars per share)	$ 0.0001
Common stock, shares authorized (in shares)	340,000,000
Common stock, shares issued (in shares)	30,022,288	29,701,146
Common stock, shares outstanding (in shares)	30,022,288	29,701,146
Class B common stock
Common stock, par value (in dollars per share)	$ 0.0001
Common stock, shares authorized (in shares)	160,000,000
Common stock, shares issued (in shares)	71,500,000	0
Common stock, shares outstanding (in shares)	71,500,000	0
Common Class C
Common stock, par value (in dollars per share)	$ 0.0001
Common stock, shares authorized (in shares)	160,000,000
Common stock, shares issued (in shares)	0	0
Common stock, shares outstanding (in shares)	0	0
Class D common stock
Common stock, par value (in dollars per share)	$ 0.0001
Common stock, shares authorized (in shares)	160,000,000
Common stock, shares issued (in shares)	72,899,037	144,399,037
Common stock, shares outstanding (in shares)	72,899,037	144,399,037

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2024	Mar. 31, 2023
Revenues:
Total revenues		$ 64,952	$ 42,957
Operating expenses:
Project development and start up costs		785	1,883
Selling, general, and administrative		13,161	14,074
Depreciation, amortization, and accretion		3,711	3,567
Income from equity method investments		(4,206)	(705)
Total expenses		61,382	53,527
Operating income (loss)		3,570	(10,570)
Other income (expense):
Interest and financing expense, net		(3,961)	(641)
Change in fair value of derivative instruments, net		403	3,933
Other income (expense)		665	(68)
Income (loss) before provision for income taxes		677	(7,346)
Provision for income taxes		0	0
Net income (loss)		677	(7,346)
Net loss attributable to redeemable non-controlling interests		(1,627)	(8,233)
Net income (loss) attributable to non-redeemable non-controlling interests		2	(297)
Dividends on redeemable preferred non-controlling interests	[1]	2,618	2,763
Net loss attributable to OPAL Fuels LLC, basic		$ (316)	$ (1,579)
Weighted average shares outstanding of Class A common stock:
Basic (in shares)		27,368,204	27,383,562
Diluted (in shares)		27,368,204	27,383,562
Per share amounts:
Basic (in dollars per share)		$ (0.01)	$ (0.06)
Diluted (in dollars per share)		$ (0.01)	$ (0.06)
RNG Fuel
Revenues:
Total revenues		$ 17,727	$ 6,749
Operating expenses:
Cost of sales		8,338	6,038
Fuel Station Services
Revenues:
Total revenues		37,142	20,828
Operating expenses:
Cost of sales		30,335	20,292
Renewable Power
Revenues:
Total revenues		10,083	15,380
Operating expenses:
Cost of sales		$ 9,258	$ 8,378
[1] Paid-in-kind preferred dividend is allocated between redeemable non-controlling interests and Class A common stockholders basis their weighted average percentage of ownership. Please see Note.13 Redeemable non-controlling interests, redeemable preferred non-controlling interests and Stockholders' deficit

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Net revenues after discount under purchase and sales agreement	$ 64,952	$ 42,957
RNG Fuel
Net revenues after discount under purchase and sales agreement	17,727	6,749
RNG Fuel | Related Party
Net revenues after discount under purchase and sales agreement	15,495	4,715
Fuel Station Services
Net revenues after discount under purchase and sales agreement	37,142	20,828
Fuel Station Services | Related Party
Net revenues after discount under purchase and sales agreement	7,741	1,493
Renewable Power
Net revenues after discount under purchase and sales agreement	10,083	15,380
Renewable Power | Related Party
Net revenues after discount under purchase and sales agreement	$ 1,526	$ 1,527

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (LOSS) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 677	$ (7,346)
Other comprehensive income (loss):
Effective portion of the cash flow hedge attributable to equity method investments	350	0
Net unrealized loss on cash flow hedges	0	(356)
Total comprehensive income (loss)	1,027	(7,702)
Net income (loss) attributable to redeemable non-controlling interests	565	(5,915)
Other comprehensive income (loss) attributable to redeemable non-controlling interests	293	(299)
Comprehensive income (loss) attributable to non-redeemable non-controlling interests	2	(297)
Dividends on Redeemable preferred non-controlling interests	426	445
Comprehensive loss attributable to Class A common stockholders	$ (259)	$ (1,636)

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN REDEEMABLE NON-CONTROLLING INTEREST, REDEEMABLE PREFERRED NON-CONTROLLING INTEREST AND STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) $ in Thousands		Total	Class A common stock	Class B common stock	Class D common stock	Redeemable Preferred non-controlling interests	Redeemable non-controlling interests	Common stock Class A common stock	Common stock Class B common stock	Common stock Class D common stock	Additional paid-in capital	Retained earnings (Accumulated deficit)	Other comprehensive income	Non-redeemable non-controlling interests	Class A common stock in treasury Class A common stock
Beginning balance at Dec. 31, 2022						$ 138,142	$ 1,013,833
Increase (Decrease) In Temporary Equity And Redeemable Noncontrolling Interest [Abstract]
Net income (loss)							(5,915)
Other comprehensive income (loss)		$ (299)					(299)
Stock-based compensation							814
Change in redemption value of Redeemable non-controlling interests							7,720
Payment of preferred dividend						2,763
Distribution of paid-in-kind preferred dividend							(2,318)
Ending balance at Mar. 31, 2023						140,905	1,013,835
Beginning balance (in shares) at Dec. 31, 2022								29,477,766		144,399,037
Beginning balance at Dec. 31, 2022		(774,156)						$ 3		$ 14	$ 0	$ (800,813)	$ 195	$ 26,445	$ 0
Treasury stock, beginning balance (in shares) at Dec. 31, 2022															0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		(1,431)										(1,134)		(297)
Other comprehensive income (loss)		(58)											(58)
Proceeds from non-redeemable non-controlling interest		3,543									1,722			1,821
Issuance of Class A common stock on warrant exchange (in shares)								49,633
Issuance of Class A common stock on warrant exchange		338									338
Cancellation of fractional shares on warrant exchange (in shares)								(26)
Exercise of put option forward purchase contract - Meteora (in shares)															(1,635,783,000)
Exercise of put option forward purchase contract - Meteora		(11,614)													$ (11,614)
Forfeiture of Class A common stock (in shares)								(197,258)
Stock-based compensation		157									157
Dividends on redeemable preferred non-controlling interests		(445)
Change in redemption value of Redeemable non-controlling interests		(7,720)									(2,217)	(5,503)
Paid-in-kind preferred dividend		(445)										(445)
Ending balance (in shares) at Mar. 31, 2023								29,330,115		144,399,037
Ending balance at Mar. 31, 2023		(791,386)						$ 3		$ 14	0	(807,895)	137	27,969	$ (11,614)
Treasury stock, ending balance (in shares) at Mar. 31, 2023															(1,635,783,000)
Beginning balance at Dec. 31, 2023						132,617	802,720
Increase (Decrease) In Temporary Equity And Redeemable Noncontrolling Interest [Abstract]
Net income (loss)							565
Other comprehensive income (loss)		293					293
Stock-based compensation							848
Dividends on redeemable preferred non-controlling interests						2,618
Dividends on redeemable preferred non-controlling interests							(2,192)
Change in redemption value of Redeemable non-controlling interests							(97,044)
Payment of preferred dividend						(5,235)
Ending balance at Mar. 31, 2024						$ 130,000	$ 705,190
Beginning balance (in shares) at Dec. 31, 2023			29,701,146	0	144,399,037			29,701,146	0	144,399,037
Beginning balance at Dec. 31, 2023		$ (477,852)						$ 3	$ 0	$ 14	0	(467,195)	(15)	955	$ (11,614)
Treasury stock, beginning balance (in shares) at Dec. 31, 2023		(1,635,783)													(1,635,783)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)		$ 112										110		2
Other comprehensive income (loss)		57											57
Issuance of Class A common stock under the ATM program (in shares)	[1]							14,005
Issuance of Class A common stock under the ATM program	[1]	97									97
Shares conversion (in shares)									71,500,000	(71,500,000)
Share conversion									$ 7	$ (7)
Issuance of Class A common stock for vesting of equity awards (in shares)	[2]							307,137
Issuance of Class A common stock for vesting of equity awards	[2]	(627)									(627)
Stock-based compensation		165									165
Distributions to non-redeemable non-controlling interests		(233)												(233)
Dividends on redeemable preferred non-controlling interests		(426)										(426)
Change in redemption value of Redeemable non-controlling interests		97,044									365	96,679
Ending balance (in shares) at Mar. 31, 2024			30,022,288	71,500,000	72,899,037			30,022,288	71,500,000	72,899,037
Ending balance at Mar. 31, 2024		$ (381,663)						$ 3	$ 7	$ 7	$ 0	$ (370,832)	$ 42	$ 724	$ (11,614)
Treasury stock, ending balance (in shares) at Mar. 31, 2024		(1,635,783)													(1,635,783)
[1] During the first quarter of 2024, the Company issued shares of Class A common stock under the Company's ATM program. Please see Note 13. Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' (Deficit) Equity for additional information. Represents the equity awards vested net of shares of Class A common stock withheld for taxes. Please see Note 16. Stock-based Compensation

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net income (loss)	$ 677	$ (7,346)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Income from equity method investments	(4,206)	(705)
Distributions from equity method investments	4,415	0
Provision for bad debts	0	492
Amortization of operating lease right-of-use assets	164	147
Depreciation and amortization	3,559	3,465
Amortization of deferred financing costs	555	450
Loss on warrant exchange	0	338
Accretion expense related to asset retirement obligation	152	102
Stock-based compensation	1,013	971
Paid-in-kind interest income	(67)	(78)
Change in fair value of Convertible Note Payable	0	563
Unrealized loss on derivative financial instruments	(307)	(4,855)
Changes in operating assets and liabilities:
Accounts receivable	4,818	611
Accounts receivable, related party	3,784	8,375
Fuel tax credits receivable	1,133	1,649
Capital spares	(171)	(13)
Parts inventory	(944)	(1,968)
Environmental credits held for sale	(1,362)	(853)
Prepaid expense and other current assets	(656)	1,078
Contract assets	(2,207)	1,227
Accounts payable	(3,989)	622
Accounts payable, related party	1,142	(507)
Fuel tax credits payable	(7)	(940)
Accrued payroll	1,400	1,547
Accrued expenses	2,524	(1,199)
Operating lease liabilities - current and non-current	(160)	(107)
Other current and non-current liabilities	987	601
Contract liabilities	1,471	504
Net cash provided by operating activities	13,718	4,171
Cash flows from investing activities:
Purchase of property, plant, and equipment	(26,752)	(38,780)
Proceeds from short term investments	3,900	27,986
Cash paid for investment in other entities	(1,500)	0
Distributions received from equity method investment	2,726	1,900
Net cash used in investing activities	(21,626)	(8,894)
Cash flows from financing activities:
Proceeds from OPAL Term Loan	0	10,000
Cash paid for taxes related to net share settlement of equity awards	(627)	0
Cash paid for purchase of shares upon exercise of put option	0	(16,391)
Financing costs paid to other third parties	(238)	(100)
Repayment of Senior Secured Credit Facility	0	(22,750)
Repayment of OPAL Term Loan	0	(6,933)
Repayment of Sunoma Loan	(380)	0
Repayment of Municipality loan	0	(45)
Repayment of equipment loan	(22)	0
Payment of preferred dividends	(5,235)	0
Distribution to non-redeemable non-controlling interest	(233)	0
Proceeds from issuance of shares of Class A common stock under the ATM program, net	97	0
Proceeds from sale of non-redeemable non-controlling interest, related party	0	3,543
Net cash used in financing activities	(6,638)	(32,676)
Net decrease in cash, restricted cash, and cash equivalents	(14,546)	(37,399)
Cash, restricted cash, and cash equivalents, beginning of period	47,242	77,221
Cash, restricted cash, and cash equivalents, end of period	32,696	39,822
Supplemental disclosure of cash flow information
Interest paid, net of $1,444 and $5,475 capitalized, respectively	3,242	1,322
Noncash investing and financing activities:
Paid-in-kind dividend on redeemable preferred non-controlling interests	0	2,763
Accrual for purchase of Property, plant and equipment included in Accounts payable and Accrued capital expenses	$ 10,743	$ 15,424

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Statement of Cash Flows [Abstract]
Interest capitalized	$ 1,444	$ 1,808	$ 5,475

Organization and Description of

Organization and Description of Business	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	Organization and Description of Business OPAL Fuels Inc. (including its subsidiaries, the "Company", “OPAL,” “we,” “us” or “our”) is a renewable energy company specializing in the capture and conversion of biogas for the (i) production of RNG for use as a vehicle fuel for heavy and medium-duty trucking fleets, (ii) generation of Renewable Power for sale to utilities, (iii) generation and sale of Environmental Attributes associated with RNG and Renewable Power, and (iv) sales of RNG as pipeline quality natural gas. The term “Environmental Attributes” refers to federal, state and local government incentives in the United States, provided in the form of RINs, RECs, LCFS credits, ISCC Carbon Credits, rebates, tax credits and other incentives to end users, distributors, system integrators and manufacturers of renewable energy projects. OPAL also designs, develops, constructs, operates and services Fueling Stations for trucking fleets across the country that use natural gas to displace diesel as their transportation fuel. The biogas conversion projects currently use landfill gas and dairy manure as the source of the biogas. In addition, we have recently begun implementing design, development, and construction services for hydrogen Fueling Stations, and we are pursuing opportunities to diversify our sources of biogas to other waste streams. The Company is organized into four operating segments based on the characteristics and the nature of products and services. The four operating segments are RNG Fuel, Fuel Station Services, Renewable Power and Corporate. All amounts in these footnotes are presented in thousands of dollars except share and per share data.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Basis of Presentation and Principles of Consolidation These condensed consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States ("U.S. GAAP") and include the accounts of the Company and all other entities in which the Company has a controlling financial interest: OPAL Renewable Power LLC (formerly Fortistar Methane 3 LLC (“FM3”) and Fortistar Methane 4 LLC), Beacon RNG LLC (“Beacon”) Sunoma Holdings, LLC (“Sunoma”), New River LLC (“New River”), Reynolds RNG LLC (“Reynolds”), Central Valley LLC (“Central Valley”), Prince William RNG LLC (“Prince William”), Cottonwood RNG LLC, Polk County RNG LLC (“Polk County”), OPAL Contracting LLC (formerly Fortistar Contracting LLC), OPAL RNG LLC (formerly Fortistar RNG LLC), and OPAL Fuel station services LLC (“Fuel Station Services”). The Company’s unaudited condensed consolidated financial statements include the assets and liabilities of these subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The non-controlling interest attributable to the Company's variable interest entities ("VIE") are presented as a separate component from the Stockholders' deficit in the condensed consolidated balance sheets and as a non-redeemable non-controlling interests in the condensed consolidated statements of changes in redeemable non-controlling interests, redeemable preferred non-controlling interests and Stockholders' (deficit) equity. Certain prior period amounts have been reclassified to conform with the current period presentation including reclassification of the Company’s proportional share of income in equity investments into operating income. See Note 3. Investment in Other Entities for further discussion. The Company reclassified certain project development and start up costs as a separate line within Operating expenses, which were previously included in Cost of sales - RNG Fuel and Selling, general and administrative expenses. Please see the Project development and start up costs section within Note 2. Additionally, the Company also reclassified certain Asset retirement obligations from current to non-current. The information included in this quarterly report should be read in conjunction with the Company's audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 as the interim disclosures generally do not repeat those in the annual financial statements. In the opinion of management, the Company's financial statements include all normal and recurring adjustments necessary in order to make the financial statements not misleading and to provide a fair presentation of the Company's financial results for the interim periods included in this Quarterly Report. Variable Interest Entities Our policy is to consolidate all entities that we control by ownership of a majority of the outstanding voting stock. In addition, we consolidate entities that meet the definition of a VIE for which we are the primary beneficiary. The Company applies the VIE model from ASC 810 when the Company has a variable interest in a legal entity not subject to a scope exception and the entity meets any of the five characteristics of a VIE. The primary beneficiary of a VIE is considered to be the party that both possesses the power to direct the activities of the entity that most significantly impact the entity’s economic performance and has the obligation to absorb losses or the rights to receive benefits of the VIE that could be significant to the VIE. To the extent a VIE is not consolidated, the Company evaluates its interest for application of the equity method of accounting. Equity method investments are included in the condensed consolidated balance sheets as “Investments in other entities.” Investments in unconsolidated entities in which the Company has influence over the operating or financial decisions are accounted for under the equity method. As of March 31, 2024, the Company accounted for its ownership interests in Pine Bend RNG LLC ("Pine Bend"), Noble Road RNG LLC ("Noble Road"), Emerald RNG LLC ("Emerald"), Sapphire RNG LLC ("Sapphire"), Paragon RNG LLC ("Paragon"), Land2Gas LLC (the "SJI Joint Venture" (RNG Atlantic and RNG Burlington)) and GREP BTB Holdings LLC ("GREP") under the equity method. Use of estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The significant estimates and assumptions of the Company include the residual value of the useful lives of our property, plant and equipment, the fair value of stock-based compensation, asset retirement obligations, the estimated losses on our trade receivables, percentage completion for revenue recognition, incremental borrowing rate for calculating the right-of-use lease assets and lease liabilities, the impairment assessment of goodwill and the fair value of derivative instruments. Actual results could differ from those estimates. The results of operations for the interim periods presented are not necessarily indicative of the results that may be expected for the entire year. Accounting Pronouncements Not Yet Adopted In November 2023, the FASB issued Accounting Standards Update No. 2023-07, Segment Reporting (Topic 280) ("ASU 2023-07"). The update improves the reportable segment disclosure requirements by requiring all entities to disclose significant segment expenses that are regularly provided to the chief operating decision maker (CODM), report other segment items (segment revenue less the significant expenses disclosed and profit or loss) by reportable segment, title and position of the CODM and an explanation of how the CODM uses the reported measure of segment profit or loss in assessing segment performance and deciding how to allocate resources. Additionally, ASU 2023-07 requires that if the CODM uses more than one measure of a segment's net income or loss in assessing segment performance and deciding how to allocate resources, the entity may report one or more of those additional measures. ASU 2023-07 is effective for fiscal years beginning after December 15, 2023 and interim periods within fiscal years beginning after December 15, 2024 and should be applied retrospectively for all periods presented. The Company expects to report significant operating expenses by segment and other additional disclosures the Company is currently evaluating, upon adoption of ASU 2023-07 in its consolidated financial statements. Emerging Growth Company Status We are an emerging growth company as defined in the JOBS Act. The JOBS Act provides emerging growth companies with certain exemptions from public company reporting requirements for up to five fiscal years while a company remains an emerging growth company. As part of these exemptions, we need only provide two fiscal years of audited financial statements instead of three, we have reduced disclosure obligations such as for executive compensation, and we are not required to comply with auditor attestation requirements from Section 404(b) of the Sarbanes-Oxley Act regarding our internal control over financial reporting. Additionally, the JOBS Act has allowed us the option to delay adoption of new or revised financial accounting standards until private companies are required to comply with new or revised financial accounting standards. Cash, Cash Equivalents, and Restricted Cash Cash, cash equivalents, and restricted cash consisted of the following as of March 31, 2024 and December 31, 2023: March 31, December 31, Current assets: Cash and cash equivalents $ 28,207 $ 38,348 Restricted cash - current (1) 1,012 4,395 Long-term assets: Restricted cash held as collateral (2) 3,477 4,499 Total cash, cash equivalents, and restricted cash $ 32,696 $ 47,242 (1) Restricted cash - current as of March 31, 2024 consists of $1,012 related to debt reserve on Sunoma Loan. Restricted cash - current as of December 31, 2023 consists of $3,361 related to debt reserve on Sunoma Loan and $1,034 relates to deposit on our interconnections payments. (2) Restricted cash held as collateral represents the collateral requirements on our debt facilities. Short term investments The Company considers highly liquid investments such as time deposits and certificates of deposit with an original maturity greater than three months at the time of purchase to be short term investments. The Short term investments of $5,975 and $9,875 as of March 31, 2024 and December 31, 2023, respectively, consists of cash invested in commercial paper with maturities ranging between 1 and 12 months as of the reporting date. The amounts in these accounts are liquid and available for general use. Our short term investments are generally invested in commercial paper issued by highly credit worthy counter parties and government backed treasury bills. Investments are generally not FDIC insured and we take counter party risk on these investments. Earnout Liabilities In connection with the Business Combination and pursuant to a sponsor letter agreement, the Sponsor agreed to subject 10% of its Class A common stock (received as a result of the conversion of its ArcLight Class B ordinary shares immediately prior to the closing) to vesting and forfeiture conditions relating to VWAP targets for the Company's Class A common stock sustained over a period of 60 months following the closing. OPAL Fuels equity holders are eligible to receive an aggregate of 10,000,000 shares of Class B and Class D common stock upon the Company achieving each earn-out event during the earn-out period. The Earnout Awards were recognized at fair value on the closing date and classified as a liability which is remeasured at each balance sheet date and any change in fair value is recognized in the Company's condensed consolidated statement of operations as part of change in fair value of derivative instruments, net. For the three months ended March 31, 2024 and 2023, the Company recorded a gain of $403 and $4,310, respectively, in its condensed consolidated statements of operations. As of March 31, 2024 and December 31, 2023, the Company recorded earnout liabilities of $1,497 and $1,900, respectively, on its condensed consolidated balance sheets. Redeemable non-controlling interests Redeemable non-controlling interests represent the portion of OPAL Fuels that the Company controls and consolidates but does not own. The Redeemable non-controlling interest was created as a result of the Business Combination and represents 144,399,037 Class B Units issued by OPAL Fuels to the prior investors. The Company allocates net income or loss attributable to Redeemable non-controlling interest based on weighted average ownership interest during the period. The net income or loss attributable to Redeemable non-controlling interests is reflected in the condensed consolidated statement of operations. At each balance sheet date, the mezzanine equity classified Redeemable non-controlling interests is adjusted up to their maximum redemption value if necessary, with an offset in Stockholders' equity. As of March 31, 2024, the maximum redemption value was $705,190. Project development and start up costs The Company has multiple RNG projects under construction for which the Company incurs certain development costs such as legal, consulting fees for joint venture structuring, royalties to the landfill owner, fines, settlements, site lease expenses and certification costs. Additionally, the Company also incurs certain expenses on new RNG projects that started operating for the first two years such as virtual pipeline costs (trucking costs incurred until a physical pipeline is connected) and ramp up costs. These costs are temporary and non-recurring over the project lifetime. Historically, the Company included these expenses in Cost of sales - RNG Fuel and Selling, general and administrative expenses with no associated revenues. For the three months ended March 31, 2024 and 2023, the Company is presenting these expenses in a separate line within operating expenses to provide additional information to the readers of the financial statements regarding the ongoing profitability of our RNG projects in operation. The following table provides information on the types of expenses classified under this expense category: Three Months Ended March 31, 2024 2023 Site lease expenses $ 275 $ 254 Legal and professional fees 288 275 Royalties — 500 Virtual pipeline costs 119 700 Management services (1) 30 126 Other 73 28 Total Project development and startup costs $ 785 1,883 (1) Relates to charges billed to the individual projects by Fortistar. See Note. 10 Related parties for additional information. Net loss per share The Company's basic earnings per share of Class A common stock is computed based on the average number of outstanding shares of Class A common stock for the period. The Company's diluted earnings per share includes effects of the Company's outstanding equity awards under the 2022 Plan (as defined elsewhere in these financial statements), Redeemable non-controlling interests (OPAL Fuels Class B units), redeemable preferred non-controlling interests, Sponsor Earnout Awards and OPAL Earnout Awards. The dilutive effect is not applicable for the periods presented. Accounts Receivable, Net The Company's allowance for credit losses was $82 and $0 at March 31, 2024 and December 31, 2023. Asset Retirement Obligation The Company accounts for asset retirement obligations in accordance with FASB ASC 410, Asset Retirement and Environmental Obligations, which requires entities to record the fair value of a liability for an asset retirement obligation in the period in which it is incurred and when a reasonable estimate of fair value can be made. The fair value of the estimated asset retirement obligations is recorded as a long-term liability, with a corresponding increase in the carrying amount of the related asset. The discounted asset retirement costs capitalized amount are accreted over the life of the sublease or site lease agreement. Asset retirement obligations are deemed Level 3 fair value measurements as the inputs used to measure the fair value are unobservable. The Company estimates the fair value of asset retirement obligations by calculating the estimated present value of the cost to retire the asset. This estimate requires assumptions and judgments regarding the existence of liabilities, the amount and timing of cash outflows required to settle the liability, inflation factors, credit adjusted discount rates, and consideration of changes in legal, regulatory, environmental, and political environments. In addition, the Company determines the Level 3 fair value measurements based on historical information and current market conditions. As of March 31, 2024 and December 31, 2023, the Company estimated the value of its total asset retirement obligations to be $6,880 and $6,728, respectively. The changes in the asset retirement obligations were as follows as of March 31, 2024: March 31, Balance, December 31, 2023 - Current and non-current $ 6,728 Payment of asset retirement obligations during the year — Accretion expense 152 Total asset retirement obligation 6,880 Less: current portion (1,812) Total asset retirement obligation, net of current portion $ 5,068 Revenue Recognition The Company’s revenue arrangements generally consist of a single performance obligation to transfer goods or services. Revenue from the sale of RNG, CNG and electricity is recognized by applying the “right to invoice” practical expedient within the accounting guidance for Revenue from Contracts with Customers that allows for the recognition of revenue from performance obligations in the amount of consideration to which there is a right to invoice the customer and when the amount for which there is a right to invoice corresponds directly to the value transferred to the customer. For some public CNG Fueling Stations where there is no contract with the customer, the Company recognizes revenue at the point in time that the customer takes control of the fuel. The Company also performs maintenance services throughout the country. Maintenance consists of monitoring equipment and replacing parts as necessary to ensure optimum performance. Revenue from service agreements is recognized over time as services are provided. Capacity payments fluctuate based on peak times of the year and revenues from capacity payments are recognized monthly as earned. The Company has agreements with two natural gas producers ("Producers") to transport Producers' natural gas using the Company's RNG gathering system. The performance obligation is the delivery of Producers' natural gas to an agreed delivery point on an interstate gas pipeline. The quantity of natural gas transported for the Producers is measured at a certain specified meter. The price is fixed at contracted rates and the Producers pay approximately 30 days after month-end. As such, transportation sales are recognized over time, using the output method to measure progress. The Company provides credit monetization services to customers that own renewable gas generation facilities. The Company recognizes revenue from these services as the credits are minted on behalf of the customer. The Company receives non-cash consideration in the form of RINs or LCFSs for providing these services and recognizes the RINs or LCFSs received as Environmental credits held for sale within current assets based on their estimated fair value at contract inception. On November 29, 2021, the Company entered into a purchase and sale agreement with NextEra, a related party, for the Environmental Attributes generated by the RNG Fuels business. Under this agreement, the Company is committed to sell a minimum of 90% of the Environmental Attributes generated and will receive net proceeds based on the agreed upon price less a specified discount. A specified volume of Environmental Attributes sold per quarter will incur a discount fee per Environmental Attribute in addition to the specified discount. The agreement was effective beginning January 1, 2022. For the three months ended March 31, 2024 and 2023, the Company earned net revenues after discount and fees of $15,495 and $4,715, respectively, under this contract which was recorded as part of Revenues - RNG Fuel. For the three months ended March 31, 2024 and 2023, the Company earned net revenues after discount and fees of $7,741 and $1,493, respectively, which was recorded as part of Revenues - Fuel Station Services. During third and fourth quarter of 2022, two of the wholly-owned subsidiaries from our Renewable Power portfolio entered into a purchase and sale agreement with an Environmental Attribute marketing firm to sell Environmental Attributes associated with renewable biomethane ("ISCC Carbon Credits") and purchase brown gas back at contracted fixed prices per million British thermal units ("MMbtu"). One of these contracts has a term of 3-years from the date of certification of the facility with an auto-renewal option. The other contract was terminated in August 2023. During the third quarter of 2023, three additional Renewable Power facilities entered into purchase and sale agreements with 3-year terms and similar terms and conditions as the previous contracts. For the three months ended March 31, 2024 and 2023, the Company earned net revenues of $3,788 and $5,445, respectively under the contracts which were recorded as part of Revenues - Renewable Power in the condensed consolidated statement of operations. Sales of Environmental Attributes such as RINs, renewable energy credits ("RECs"), ISCC Carbon Credits and LCFS are generally recorded as revenue when the certificates related to them are delivered to a buyer. However, the Company may recognize revenue from the sale of such Environmental Attributes at the time of the related Renewable Power sales when the contract provides that title to the Environmental Attributes transfers at the time of production, the Company's price to the buyer is fixed, and collection of the sales proceeds is certain. Management operating fees are earned for the operation, maintenance, and repair of the gas collection system of a landfill site. Revenue is calculated on the volume of per million British thermal units of LFG collected and the megawatt hours ("MWhs") produced at that site. This revenue is recognized when LFG is collected and Renewable Power is delivered. The Company has various fixed price contracts for the construction of Fueling Stations for customers. Revenues from these contracts, including change orders, are recognized over time, with progress measured by the percentage of costs incurred to date compared to estimated total costs for each contract. This method is used as management considers costs incurred to be the best available measure of progress on these contracts. Costs capitalized to fulfill certain contracts were not material in any of the periods presented. The Company owns Fueling Stations for use by customers under fuel sale agreements. The Company bills these customers at an agreed upon price for each gallon sold and recognizes revenue based on the amounts invoiced in accordance with the "right to invoice" practical expedient. For some public stations where there is no contract with the customer, the Company recognizes revenue at the point-in-time that the customer takes control of the fuel. The Company from time-to-time enters into fuel purchase agreements with customers whereby the Company is contracted to design and build a Fueling Station on the customer's property in exchange for the Company providing CNG/RNG to the customer for a determined number of years. In accordance with the standards of ASC 840, Leases , the Company has concluded these agreements meet the criteria for a lease and are classified as operating leases. Typically, these agreements do not require any minimum consumption amounts and, therefore, no minimum payments. Upon adoption of ASC 842, the Company adopted the practical expedient not to reassess the classification. For additional information on lease revenues earned, please see Note 8. Leases. Disaggregation of Revenue The following table shows the disaggregation of revenue according to product line: Three Months Ended 2024 2023 Renewable Power sales $ 5,819 $ 9,604 Third party construction 10,790 7,154 Service 5,335 4,904 Brown gas sales 5,602 7,530 Environmental credits (1) 35,677 12,677 Parts sales 397 187 Other 341 — Total revenue from contracts with customers 63,961 42,056 Lease revenue (2) 991 901 Total revenue $ 64,952 $ 42,957 (1) Includes revenues of $3,617 and $5,168 for the three months ended March 31, 2024 and 2023, from customers domiciled outside of United States. (2) Lease revenue relates to approximately twenty-six fuel purchasing agreements out of which we have two of our RNG fuel stations with minimum take or pay provisions and revenue from power purchase agreements at two of our Renewable Power facilities where we determined that we transferred the right to control the use of the power plant to the purchaser. For the three months ended March 31, 2024 and 2023, 16.6% and 16.6%, respectively of revenue was recognized over time, and the remainder was for products and services transferred at a point in time. Other income (expense) The following table shows the items consisting of items recorded as Other income (expense): Three Months Ended March 31, 2024 2023 Gain on transfer of non-financial asset in exchange for services received (1) $ 665 $ 270 Loss on warrant exchange — (338) Other income (expense) $ 665 $ (68) (1) Represents the fair value of RINs transferred as consideration for services received. Contract Balances The following table provides information about receivables, contract assets, and contract liabilities from contracts with customers: March 31, December 31, Accounts receivable, net $ 22,805 $ 27,623 Contract assets: Cost and estimated earnings in excess of billings $ 6,818 $ 4,630 Accounts receivable retainage, net 2,179 2,160 Contract assets total $ 8,997 $ 6,790 Contract liabilities: Billings in excess of costs and estimated earnings $ 7,785 $ 6,314 Contract liabilities total $ 7,785 $ 6,314 During the three months ended March 31, 2024, the Company recognized revenue of $2,746 that was included in "Contract liabilities" at December 31, 2023. During the three months ended March 31, 2023, the Company recognized revenue of $8,013 that was included in "Contract liabilities" at December 31, 2022. Environmental credits held for sale The Company provides dispensing and credit monetization services to OPAL owned facilities and third-party customers that own renewable gas generation facilities. The Company recognizes revenue from these services as the credits are minted on behalf of the customer. The Company receives non-cash consideration in the form of RINs or LCFSs for providing these services and recognizes the environmental credits received as part of Revenues - Fuel Station Services and Environmental credits held for sale within current assets based on their estimated fair value at contract inception. It is recorded at historical fair value at contract inception and reviewed to ensure it is recorded at lower of cost and net realizable value at each balance sheet date. Due to the historically higher LCFS pricing, the fair value at contract inception may be significantly higher than the net realizable value of the environmental credits generated at the period-end balance sheet date. For the three months ended March 31, 2024 and 2023, the Company recorded $3,156 and $1,218 as part of Cost of sales - Fuel Station Services in its condensed consolidated statements of operations to adjust environmental credits held for sale to lower of cost and net realizable value. Fuel Station Services Construction Backlog The Company's remaining performance obligations ("backlog") represent the unrecognized revenue value of its contract commitments. The Company's backlog may significantly vary each reporting period based on the timing of major new contract commitments. At March 31, 2024, the Company had a backlog of $43,731 of which $32,917 is anticipated to be recognized as revenue in the next 12 months. Major Maintenance Major maintenance is a component of maintenance expense and encompasses overhauls of internal combustion engines, gas compressors and electrical generators. Major maintenance is expensed as incurred. Major maintenance expense was $2,909 and $2,076 for the three months ended March 31, 2024 and 2023 respectively, and is included in cost of sales — Renewable Power in the consolidated statements of operations. Vulnerability Due to Certain Concentrations Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash, cash equivalents, restricted cash, short term investments, derivative instruments and trade accounts receivable. The Company holds cash, cash equivalents and restricted cash at several major financial institutions, much of which exceeds FDIC insured limits. Historically, the Company has not experienced any losses due to such concentration of credit risk. The Company’s temporary cash investments policy is to limit the dollar amount of investments with any one financial institution and monitor the credit ratings of those institutions. While the Company may be exposed to credit losses due to the nonperformance of the holders of its deposits, the Company does not expect the settlement of these transactions to have a material effect on its results of operations, cash flows or financial condition. Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, Accounting for Income Taxes (“ASC Topic 740”), which requires the recognition of tax benefits or expenses on temporary differences between the financial reporting and tax bases of its assets and liabilities by applying the enacted tax rates in effect for the year in which the differences are expected to reverse. Such net tax effects on temporary differences are reflected on the Company’s condensed consolidated balance sheets as deferred tax assets and liabilities. Deferred tax assets are reduced by a valuation allowance when the Company believes that it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The Company calculates the interim tax provision in accordance with the provisions of ASC Subtopic 740-270, Income Taxes; Interim Reporting. For interim periods, the Company estimates the annual effective income tax rate and applies the estimated rate to the year-to-date income or loss before income taxes. Significant Customers, Vendors and Concentration of Credit Risk For the three months ended March 31, 2024, two customers accounted for 55% of the revenue. For the three months ended March 31, 2023, three customers accounted for 44% of the revenue. At March 31, 2024, two customers accounted for 58% of accounts receivable. At December 31, 2023, two customers accounted for 54% of accounts receivable. Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, and trade receivables. The Company places its cash with high credit quality financial institutions located in the United States of America. The Company performs ongoing credit evaluations of its customers. As of March 31, 2024 ,

Investments in Other Entities

Investments in Other Entities	3 Months Ended
	Mar. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Investments in Other Entities	Investment in Other Entities The Company uses the equity method to account for investments in affiliates that it does not control, but in which it has the ability to exercise significant influence over operating and financial policies. The Company's investments in these nonconsolidated affiliates are reflected in the Company's condensed consolidated balance sheets under the equity method, and the Company's proportionate net income, if any, is included in the Company's condensed consolidated statements of operations as income from equity method investments. We continue to evaluate operational developments and the impact of the anticipated expansion of the operations of our existing equity method investments. Based on our analysis, it was determined that our equity method investments have evolved into a critical, integral part of our RNG segment business operations as they provide critical additional production capacity. Therefore, we have determined that the presentation of income (loss) from equity method investments as part of the operating income is more meaningful and useful information to the readers of our financial statements. As a result, we have reclassified our portion of income (loss) from equity method investments to Operating income for all periods presented. The following table shows the movement of Investment in Other Entities: Pine Bend Noble Road GREP SJI Paragon Total Percentage of ownership 50 % 50 % 20 % 50 % 50 % Balance at December 31, 2023 $ 21,062 $ 22,174 $ 2,015 $ 1,567 $ 160,281 $ 207,099 Net income from equity method investment 1,042 1,469 (71) (59) 3,255 5,636 Contribution by the Company — — — 1,500 — 1,500 Distributions from return on investment in equity method investment (1) (996) (1,400) — — (2,019) (4,415) Distributions from return of investment in equity method investment (2) (104) — — — (2,622) (2,726) Accumulated other comprehensive income — — — — 350 350 Amortization of basis difference (3) (46) (147) — — (1,237) (1,430) Balance at March 31, 2024 $ 20,958 $ 22,096 $ 1,944 $ 3,008 $ 158,008 $ 206,014 (1) Recorded as part of cash flows from operating activities for the three months ended March 31, 2024. (2) Recorded as part of cash flows from investing activities for the three months ended March 31, 2024. (3) Reflected in Income from equity method investments in the condensed consolidated statement of operations for the three months ended March 31, 2024. The following table summarizes the activity from our equity method investments as well as our share of net income from equity method investments: Three Months Ended March 31, 2024 2023 Revenue $ 25,407 $ 7,539 Gross profit 11,094 1,651 Net income (loss) 10,704 (213) Net income from equity method investments (1) $ 4,206 $ 705 (1)

Property, Plant, and Equipment,

Property, Plant, and Equipment, Net	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Property, Plant, and Equipment, Net	Property, Plant, and Equipment, Net Property, plant, and equipment, net, consisted of the following as of March 31, 2024 and December 31, 2023: March 31, December 31, Plant and equipment $ 198,174 $ 205,188 CNG/RNG fueling stations 56,529 51,749 Construction in progress (1) 193,006 175,060 Buildings 2,585 2,585 Land 1,303 1,303 Service equipment 2,499 2,481 Leasehold improvements 815 815 Vehicles 489 489 Office furniture and equipment 307 307 Computer software 277 277 Land lease - finance lease 6,283 6,469 Vehicles - finance leases 2,460 2,580 Other 591 591 465,318 449,894 Less: accumulated depreciation (105,949) (110,401) Property, plant, and equipment, net $ 359,369 $ 339,493 (1) Includes capitalized interest of $1,444 and $5,475, respectively, for the three months ended March 31, 2024 and year ended December 31, 2023. On October 20, 2023, our wholly owned subsidiary entered into an Asset Purchase and Sale Agreement (for the purposes of this paragraph, the “Agreement”) with Washington Gas Light Company ("WGL"). The subsidiary is currently constructing a production facility at the Prince William County landfill located in Manassas, Virginia, to process landfill gas into RNG. The Agreement obligates the subsidiary to develop, plan and permit a gas pipeline extension and associated interconnection facilities (the “Pipeline Project”) to deliver RNG from the facility to an interconnection point on WGL’s pipeline. Per the terms and conditions of the Agreement, WGL will purchase the Pipeline Project from the subsidiary after its final completion at a purchase price of $25 million. The closing is contingent upon approval of the Agreement by the Virginia State Corporation Commission, as well as the satisfaction of customary closing conditions, and the outside closing date is on or prior to October 20, 2024. As of March 31, 2024, we have recorded capital expenditure of $2.5 million which is included in the Property, Plant and Equipment on our condensed consolidated balance sheet. As of March 31, 2024, the Construction in progress consists of capital expenditures on construction of RNG generation facilities including, but not limited to Prince William, Polk County, Cottonwood, Central Valley RNG projects and RNG dispensing facilities. The majority of these facilities, for which costs are in construction in progress as of March 31, 2024, are expected to be operational during late 2024 and mid 2025.

Intangible Assets, Net

Intangible Assets, Net	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Intangible Assets, Net	Intangible Assets, Net Intangible assets, net, consisted of the following at March 31, 2024 and December 31, 2023: March 31, 2024 Cost Accumulated Intangible Weighted Power purchase agreements $ 8,999 $ (7,469) $ 1,530 18.1 Transmission/distribution interconnection 1,600 (1,600) — 15.1 Intellectual property 43 (36) 7 5.0 Total intangible assets $ 10,642 $ (9,105) $ 1,537 December 31, 2023 Cost Accumulated Intangible Weighted Power purchase agreements $ 8,999 $ (7,926) $ 1,073 18.1 Transmission/distribution interconnection 1,600 (1,076) 524 15.1 Intellectual property 43 (36) 7 5.0 Total intangible assets $ 10,642 $ (9,038) $ 1,604 Amortization expense for the three months ended March 31, 2024 and 2023 was $67 and $160, respectively. At March 31, 2024, estimated future amortization expense for intangible assets is as follows: Nine months ending December 31, 2024 $ 205 Fiscal year: 2025 267 2026 231 2027 171 2028 171 Thereafter 492 $ 1,537

Goodwill

Goodwill	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	Goodwill The following table summarizes the changes in goodwill, if any, by reporting segment from the beginning of the period to the end of the period: RNG Fuel Fuel Station Services Total Balance December 31, 2023 $ 51,155 $ 3,453 $ 54,608 Balance March 31, 2024 $ 51,155 $ 3,453 $ 54,608

Borrowings

Borrowings	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Borrowings	Borrowings The following table summarizes the borrowings under the various debt facilities as of March 31, 2024 and December 31, 2023: March 31, 2024 December 31, 2023 OPAL Term Loan 186,618 186,618 Less: unamortized debt issuance costs (9,591) (10,086) Less: current portion (1,866) — OPAL Term Loan, net of debt issuance costs 175,161 176,532 Sunoma Loan 22,074 22,453 Less: unamortized debt issuance costs (813) (835) Less: current portion (1,652) (1,608) Sunoma Loan, net of debt issuance costs 19,609 20,010 Non-current borrowings total $ 194,770 $ 196,542 As of March 31, 2024, principal maturities of debt are expected as follows, excluding any subsequent refinancing transactions and any undrawn debt facilities as of the date of the condensed consolidated balance sheets: OPAL Term Loan Sunoma Loan Total Nine months ending December 31, 2024 $ — $ 1,229 $ 1,229 Fiscal year: 2025 7,354 1,756 9,110 2026 7,064 1,898 8,962 2027 6,786 2,051 8,837 2028 165,414 2,213 167,627 Thereafter — $ 12,927 $ 12,927 $ 186,618 $ 22,074 $ 208,692 OPAL Term Loan On October 22, 2021, OPAL Fuels Intermediate Holding Company LLC (“OPAL Intermediate Holdco”), an indirect wholly-owned subsidiary of the Company, entered into a $125,000 term loan agreement (the "OPAL Term Loan") with a syndicate of lenders. On September 1, 2023, OPAL Intermediate Holdco restructured its existing credit agreement and entered into a new senior secured credit facility (the "Credit Agreement") with OPAL Intermediate HoldCo as the Borrower, direct and indirect subsidiaries of the Borrower as guarantors (the “Guarantors”), the lenders party thereto, as lenders, Apterra Infrastructure Capital LLC, Barclays Bank PLC, BofA Securities, Inc., Celtic Bank Corporation, Citibank, N.A., JP Morgan Chase Bank, N.A. Investec Inc. and ICBC Standard Bank PLC, as joint lead arrangers, and Bank of America, N.A., as administrative agent. Four of the existing lenders participated in the new credit facility. The Credit Agreement provides for up to $450.0 million of initial and delayed draw term loans (with such delayed draw term loans available for up to 18 months after closing) and $50.0 million of revolving loans. The proceeds from the facility are expected to be used to fund other general corporate purposes of the Borrower and Guarantors. The Company paid transaction fees and expenses in the amount of approximately $9,976. The amounts outstanding under the Credit Agreement are secured by the assets of the indirect subsidiaries of OPAL Intermediate Holdco.. As of March 31, 2024 and December 31, 2023, the outstanding loan balance (current and non-current) excluding deferred financing costs was $186,618. Additionally, the Company utilized $13,604 of availability under the revolver loan to provide for the issuance of letters of credit to support the operations of the Borrower and the Guarantors. The outstanding loans under the Credit Agreement initially bear interest at an annual rate of Term SOFR plus 3.5%, increasing by 0.25% per annum during the term. Commencing March 31, 2025, the outstanding principal amount of the term loans amortizes at a rate of 1% per quarter and the Borrower is obligated to pay a leverage based cash sweep ranging from 25% to 100% of distributable cash of Borrower and the Guarantors, and subject to certain other mandatory prepayment requirements. The term loans and revolving loans mature on September 1, 2028. The Credit Agreement requires the Borrower to maintain a consolidated debt service coverage ratio of not less than 1.2 to 1.0, as tested on a trailing four quarters basis as of the last day of each fiscal quarter during the term commencing with the quarter ended December 31, 2023, and to maintain a consolidated debt to cash flow ratio of not greater than 4.5 to 1.0 during the delayed draw availability period, and not greater than 4.0 to 1.0 thereafter. The Credit Agreement includes certain customary and project-related affirmative and negative covenants, including restrictions on distributions, and events of default, which include payment defaults breaches of covenants; changes of control materially incorrect or misleading representations or warranties bankruptcy or other events of insolvency and certain project-related defaults. As of March 31, 2024, the Company is in compliance with the financial covenants under the OPAL Term Loan. Additionally, the OPAL Term Loan contains restrictions on distributions and additional indebtedness. The Company has the ability, during the delayed draw availability period and subject to the satisfaction of certain credit and project-related conditions precedent, to join other newly acquired subsidiaries with comparable renewable projects in development under the Credit Facility for comparable funding. Sunoma Loan On August 27, 2020, Sunoma, an indirect wholly-owned subsidiary of the Company entered into a debt agreement (the "Sunoma Loan Agreement") with Live Oak Banking Company for an aggregate principal amount of $20,000. Sunoma paid $635 as financing fees. The loan bears interest at the greater of prime rate plus 3.50%, or 7.75%. The amounts outstanding under the Sunoma Loan are secured by the assets of Sunoma. The Sunoma Loan Agreement contains certain financial covenants which require Sunoma to maintain (i) maximum debt to net worth ratio not to exceed 5:1 (ii) a minimum current ratio not be less than 1.0 and (iii) minimum debt service coverage ratio of trailing four quarters not be less than 1.25. On July 19, 2022, Sunoma completed the conversion of the construction loan into a permanent loan and increased the commitment from $20,000 to $23,000. The borrowings under the Sunoma Loan Agreement bear interest at a rate of 7.68% and have a maturity date of July 19, 2033. The Company is required to pay a quarterly amortization of principal of $380 beginning in October 2023. As of March 31, 2024 and December 31, 2023, the outstanding loan balance (current and non-current) excluding deferred financing costs was $22,074 and $22,453, respectively. The significant assets of Sunoma are parenthesized in the condensed consolidated balance sheets as March 31, 2024 and December 31, 2023. See Note 12. Variable Interest Entities for additional information. Convertible Note Payable On May 1, 2021, the Company acquired the remaining ownership interests in Beacon and signed an unsecured, contingently convertible note (the "Convertible Note") with Ares for a total aggregate amount for $50,000 at an interest rate of 8.00% per annum. The Company repaid the outstanding balance in full on September 1, 2023. Municipality Loan FM3, an indirect wholly-owned subsidiary of the Company, entered into a loan agreement for the construction of an interconnection that was initially funded by the municipality. The loan was fully repaid in April 2023. Senior Secured Credit Facility On September 21, 2015, FM3, an indirect wholly-owned subsidiary of the Company, entered into a senior secured credit facility (the "Senior Secured Credit Facility") as a borrower and a syndicate of lenders, which provides for an aggregate principal amount of $150,000, consisting of (i) a term loan of $125,000 and a (ii) working capital letter of credit facility of up to $19,000 and a (iii) debt service reserve and liquidity facility of up to $6,000. On March 20, 2023, the Company repaid in full the remaining outstanding loan under this facility. Interest rates 2024 For the three months ended March 31, 2024, the weighted average effective interest rate including amortization of debt issuance costs on OPAL Term Loan was 7.30%. For the three months ended March 31, 2024, the interest rate on Sunoma Loan was 8.60%. 2023 For the three months ended March 31, 2023, the weighted average effective interest rate on Senior Secured Credit Facility including amortization of debt issuance costs on Senior Secured Credit Facility was 5.60% including a margin plus LIBOR. The debt was repaid in full in March 2023. For the three months ended March 31, 2023, the weighted average effective interest rate on OPAL Term Loan including amortization of debt issuance costs was 8.40%. For three months ended March 31, 2023, the interest rate on Sunoma loan was 7.84%. For the three months ended March 31, 2023, the payment-in-kind interest rate on Convertible Note Payable was 8.00%. For the three months ended March 31, 2023, the weighted average interest rate on Municipality loan was 3.00%. The following table summarizes the Company's total interest expense for the three months ended March 31, 2024 and 2023: Three Months Ended 2024 2023 Senior Secured Credit Facility $ 2 $ 281 Convertible Note Payable mark-to-market — 563 Sunoma Loan 461 445 OPAL Term Loan (1) 2,769 19 Equipment loan (2) 5 — Commitment fees and other finance fees 688 128 Amortization of deferred financing cost 555 450 Interest expense on finance leases 147 16 Interest income (666) (1,261) Total interest expense $ 3,961 $ 641 (1) Excludes $1,444 and $1,808 of interest capitalized and recorded as part of Property, Plant and Equipment for the three months ended March 31, 2024 and 2023, respectively. (2) Sunoma equipment loan recorded as part of Other current liabilities and Other long-term liabilities as of March 31, 2024.

Leases

Leases	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Leases	Leases The following are the type of contracts that fall under ASC 842: Lessor contracts Fuel Provider agreements Fuel provider agreements ("FPAs") are for the sale of brown gas, service and maintenance of sites. The Company is contracted to design and build a Fueling Station on the customer's property in exchange for the Company providing CNG/RNG to the customer for a determined number of years. These are considered to be operating leases with variable consideration. As per ASC 842, the revenue is recognized in the period earned. Power Purchase agreements Power purchase agreements ("PPAs") are for the sale of electricity generated at our Renewable Power facilities. All of our Renewable Power facilities operate under fixed pricing or indexed pricing based on market prices. Two of our Renewable Power facilities transfer the right to control the use of the power plant to the purchaser and are therefore classified as operating leases. There were no amendments to these two contracts after the Adoption Date. Included in Fuel Station Services revenues are $772 and $570 related to the lease portion of the FPAs for the three months ended March 31, 2024 and 2023, respectively. Included in Renewable Power revenues are $219 and $331 related to the lease element of the PPAs for the three months ended March 31, 2024 and 2023, respectively. Lessee contracts Ground/Site leases The Company through various of its indirectly owned subsidiaries holds site leases on landfills/dairy farms to build RNG generation facilities. Typically, the lease payments over the lease term are immaterial except for three of our RNG facilities - Beacon and two sites at our Central Valley project - MS Digester ("MS") and VS Digester ("VS"). On December 27, 2023, OPAL entered into an Amended and Restated Lease Agreement which amended the payment terms to include a minimum volume requirement that requires OPAL to pay lease payments of $1 per GGE of CNG pumped with annual minimum volumes for the lease term. The Company determined that the site lease is a finance lease because the present value of the sum of the lease payments is substantially greater than the fair value of the parcel of land. Therefore, the Company recorded right-of-use asset and related lease liability on December 27, 2023. Office lease The Company entered into a lease for office and warehouse space that became effective upon the termination of the original lease term on January 31, 2018. The term of the lease renewal was 36 months and contained an option to renew for an additional 24 months. In September 2020, the Company exercised this option. In March 2022, the Company entered into an amendment to the lease which extended the lease term till January 2026. The Company determined that the three site leases and the one office lease as operating leases. Under ASC 842, leases are classified as either finance or operating arrangements, with such classification affecting the pattern and classification of expense recognition in an entity's income statement. For operating leases, ASC 842 requires recognition in an entity’s income statement of a single lease expense, calculated so that the cost of the lease is allocated over the lease term, generally on a straight-line basis. Right-of-use assets represent a right to use an underlying asset for the lease term and the related lease liability represents an obligation to make lease payments pursuant to the contractual terms of the lease agreement. Based on the above guidance, the lease expense for the site leases is included as part of Cost of sales - RNG Fuel in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. The lease expense for the office lease is recorded as part Selling, general and administrative expenses in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. Vehicle leases The Company leases approximately 104 vehicles in our FM3 and OPAL Fuel Station Services subsidiaries. The leases contain repurchase options at the end of the lease term and the sum total of the lease payments represents substantially the fair value of the asset. Under ASC 842, the Company determined that the vehicle leases are finance leases. For finance leases, ASC 842 requires recognition of amortization of right-of-use asset as part of depreciation and amortization expense and the interest on the finance lease liability as interest expense in the income statement. The Company accordingly recognized its lease expense on the vehicle leases as part of Depreciation, amortization and accretion expense and interest and financing expense, net in its condensed statement of operations for the three months ended March 31, 2024 and 2023. Lease Disclosures Under ASC 842 The objective of the disclosure requirements under ASC 842 is to enable users of an entity’s financial statements to assess the amount, timing and uncertainty of cash flows arising from lease arrangements. In addition to the supplemental qualitative leasing disclosures included above, below are quantitative disclosures that are intended to meet the stated objective of ASC 842. Right-of-use assets and Lease liabilities as of March 31, 2024 and December 31, 2023 are as follows: Description Location in Balance Sheet March 31, 2024 December 31, 2023 Assets: Operating leases (1) : Site leases Right-of-use assets $ 11,278 $ 11,330 Office lease Right-of-use assets 859 971 12,137 12,301 Finance leases (1) : Vehicle leases Property, plant and equipment, net 2,460 2,580 Site leases Property, plant and equipment, net 6,283 6,468 8,743 9,048 Total right-of-use assets $ 20,880 $ 21,349 Liabilities (1) : Sites leases - operating Lease liabilities - current portion 138 $ 130 Office lease - operating Lease liabilities - current portion 518 508 Vehicle leases - finance Accrued expenses and other current liabilities 862 827 Site leases - finance Accrued expenses and other current liabilities 583 571 2,101 2,036 Sites leases - operating Operating lease liabilities - non-current portion 11,178 11,222 Office lease - operating Operating lease liabilities - non-current portion 468 602 Vehicle leases - finance Other long-term liabilities 1,661 1,801 Site leases - finance Other long-term liabilities $ 5,679 $ 5,587 18,986 19,212 Total lease liabilities $ 21,087 $ 21,248 (1) The Operating and Finance lease right-of-use asset and Operating and Finance lease liabilities represent the present value of lease payments for the remaining term of the lease. The discount rate used ranged from 3.59% to 8.44%. The table below presents components of the Company's lease expense for the three months ended March 31, 2024 and 2023: Description Location in Statement of Operations Three Months Ended March 31, 2024 2023 Operating lease expense for site leases Cost of sales - RNG Fuel $ 283 $ 263 Operating lease expense for office lease Selling, general, administrative expenses 121 121 Amortization of right-of-use assets - finance leases Depreciation, amortization and accretion expense 234 140 Interest expense on lease liabilities - finance leases Interest and financing expense, net 147 16 $ 785 $ 540 The Company does not have material short term lease expense for the three months ended March 31, 2024 and 2023. The Company did not enter into any operating leases greater than 12 months for the three months ended March 31, 2024. Weighted average remaining lease term (years) March 31, 2024 Operating leases 19.2 Financing leases 6.8 Weighted average discount rate Operating leases 7.85 % Financing leases 6.60 % The table below provides the total amount of lease payments on an undiscounted basis on our lease contracts as of March 31, 2024: Site leases Office leases Vehicle leases Site lease - Finance Total Weighted average discount rate 7.6 % 3.6 % 6.3 % 6.5 % 2024 $ 797 $ 406 $ 804 $ 963 $ 2,970 2025 1,129 562 966 963 3,620 2026 1,129 47 810 963 2,949 2027 1,129 — 429 963 2,521 2028 and beyond 20,310 — 5 4,250 24,565 24,494 1,015 3,014 8,102 36,625 Present value of lease liability 11,316 986 2,523 6,262 21,087 Lease liabilities - current portion 138 518 862 583 2,101 Lease liabilities - non-current portion 11,178 468 1,661 5,679 18,986 Total lease liabilities $ 11,316 $ 986 $ 2,523 $ 6,262 $ 21,087 Discount based on incremental borrowing rate $ 13,178 $ 29 $ 491 $ 1,840 $ 15,538
Leases	Leases The following are the type of contracts that fall under ASC 842: Lessor contracts Fuel Provider agreements Fuel provider agreements ("FPAs") are for the sale of brown gas, service and maintenance of sites. The Company is contracted to design and build a Fueling Station on the customer's property in exchange for the Company providing CNG/RNG to the customer for a determined number of years. These are considered to be operating leases with variable consideration. As per ASC 842, the revenue is recognized in the period earned. Power Purchase agreements Power purchase agreements ("PPAs") are for the sale of electricity generated at our Renewable Power facilities. All of our Renewable Power facilities operate under fixed pricing or indexed pricing based on market prices. Two of our Renewable Power facilities transfer the right to control the use of the power plant to the purchaser and are therefore classified as operating leases. There were no amendments to these two contracts after the Adoption Date. Included in Fuel Station Services revenues are $772 and $570 related to the lease portion of the FPAs for the three months ended March 31, 2024 and 2023, respectively. Included in Renewable Power revenues are $219 and $331 related to the lease element of the PPAs for the three months ended March 31, 2024 and 2023, respectively. Lessee contracts Ground/Site leases The Company through various of its indirectly owned subsidiaries holds site leases on landfills/dairy farms to build RNG generation facilities. Typically, the lease payments over the lease term are immaterial except for three of our RNG facilities - Beacon and two sites at our Central Valley project - MS Digester ("MS") and VS Digester ("VS"). On December 27, 2023, OPAL entered into an Amended and Restated Lease Agreement which amended the payment terms to include a minimum volume requirement that requires OPAL to pay lease payments of $1 per GGE of CNG pumped with annual minimum volumes for the lease term. The Company determined that the site lease is a finance lease because the present value of the sum of the lease payments is substantially greater than the fair value of the parcel of land. Therefore, the Company recorded right-of-use asset and related lease liability on December 27, 2023. Office lease The Company entered into a lease for office and warehouse space that became effective upon the termination of the original lease term on January 31, 2018. The term of the lease renewal was 36 months and contained an option to renew for an additional 24 months. In September 2020, the Company exercised this option. In March 2022, the Company entered into an amendment to the lease which extended the lease term till January 2026. The Company determined that the three site leases and the one office lease as operating leases. Under ASC 842, leases are classified as either finance or operating arrangements, with such classification affecting the pattern and classification of expense recognition in an entity's income statement. For operating leases, ASC 842 requires recognition in an entity’s income statement of a single lease expense, calculated so that the cost of the lease is allocated over the lease term, generally on a straight-line basis. Right-of-use assets represent a right to use an underlying asset for the lease term and the related lease liability represents an obligation to make lease payments pursuant to the contractual terms of the lease agreement. Based on the above guidance, the lease expense for the site leases is included as part of Cost of sales - RNG Fuel in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. The lease expense for the office lease is recorded as part Selling, general and administrative expenses in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. Vehicle leases The Company leases approximately 104 vehicles in our FM3 and OPAL Fuel Station Services subsidiaries. The leases contain repurchase options at the end of the lease term and the sum total of the lease payments represents substantially the fair value of the asset. Under ASC 842, the Company determined that the vehicle leases are finance leases. For finance leases, ASC 842 requires recognition of amortization of right-of-use asset as part of depreciation and amortization expense and the interest on the finance lease liability as interest expense in the income statement. The Company accordingly recognized its lease expense on the vehicle leases as part of Depreciation, amortization and accretion expense and interest and financing expense, net in its condensed statement of operations for the three months ended March 31, 2024 and 2023. Lease Disclosures Under ASC 842 The objective of the disclosure requirements under ASC 842 is to enable users of an entity’s financial statements to assess the amount, timing and uncertainty of cash flows arising from lease arrangements. In addition to the supplemental qualitative leasing disclosures included above, below are quantitative disclosures that are intended to meet the stated objective of ASC 842. Right-of-use assets and Lease liabilities as of March 31, 2024 and December 31, 2023 are as follows: Description Location in Balance Sheet March 31, 2024 December 31, 2023 Assets: Operating leases (1) : Site leases Right-of-use assets $ 11,278 $ 11,330 Office lease Right-of-use assets 859 971 12,137 12,301 Finance leases (1) : Vehicle leases Property, plant and equipment, net 2,460 2,580 Site leases Property, plant and equipment, net 6,283 6,468 8,743 9,048 Total right-of-use assets $ 20,880 $ 21,349 Liabilities (1) : Sites leases - operating Lease liabilities - current portion 138 $ 130 Office lease - operating Lease liabilities - current portion 518 508 Vehicle leases - finance Accrued expenses and other current liabilities 862 827 Site leases - finance Accrued expenses and other current liabilities 583 571 2,101 2,036 Sites leases - operating Operating lease liabilities - non-current portion 11,178 11,222 Office lease - operating Operating lease liabilities - non-current portion 468 602 Vehicle leases - finance Other long-term liabilities 1,661 1,801 Site leases - finance Other long-term liabilities $ 5,679 $ 5,587 18,986 19,212 Total lease liabilities $ 21,087 $ 21,248 (1) The Operating and Finance lease right-of-use asset and Operating and Finance lease liabilities represent the present value of lease payments for the remaining term of the lease. The discount rate used ranged from 3.59% to 8.44%. The table below presents components of the Company's lease expense for the three months ended March 31, 2024 and 2023: Description Location in Statement of Operations Three Months Ended March 31, 2024 2023 Operating lease expense for site leases Cost of sales - RNG Fuel $ 283 $ 263 Operating lease expense for office lease Selling, general, administrative expenses 121 121 Amortization of right-of-use assets - finance leases Depreciation, amortization and accretion expense 234 140 Interest expense on lease liabilities - finance leases Interest and financing expense, net 147 16 $ 785 $ 540 The Company does not have material short term lease expense for the three months ended March 31, 2024 and 2023. The Company did not enter into any operating leases greater than 12 months for the three months ended March 31, 2024. Weighted average remaining lease term (years) March 31, 2024 Operating leases 19.2 Financing leases 6.8 Weighted average discount rate Operating leases 7.85 % Financing leases 6.60 % The table below provides the total amount of lease payments on an undiscounted basis on our lease contracts as of March 31, 2024: Site leases Office leases Vehicle leases Site lease - Finance Total Weighted average discount rate 7.6 % 3.6 % 6.3 % 6.5 % 2024 $ 797 $ 406 $ 804 $ 963 $ 2,970 2025 1,129 562 966 963 3,620 2026 1,129 47 810 963 2,949 2027 1,129 — 429 963 2,521 2028 and beyond 20,310 — 5 4,250 24,565 24,494 1,015 3,014 8,102 36,625 Present value of lease liability 11,316 986 2,523 6,262 21,087 Lease liabilities - current portion 138 518 862 583 2,101 Lease liabilities - non-current portion 11,178 468 1,661 5,679 18,986 Total lease liabilities $ 11,316 $ 986 $ 2,523 $ 6,262 $ 21,087 Discount based on incremental borrowing rate $ 13,178 $ 29 $ 491 $ 1,840 $ 15,538
Leases	Leases The following are the type of contracts that fall under ASC 842: Lessor contracts Fuel Provider agreements Fuel provider agreements ("FPAs") are for the sale of brown gas, service and maintenance of sites. The Company is contracted to design and build a Fueling Station on the customer's property in exchange for the Company providing CNG/RNG to the customer for a determined number of years. These are considered to be operating leases with variable consideration. As per ASC 842, the revenue is recognized in the period earned. Power Purchase agreements Power purchase agreements ("PPAs") are for the sale of electricity generated at our Renewable Power facilities. All of our Renewable Power facilities operate under fixed pricing or indexed pricing based on market prices. Two of our Renewable Power facilities transfer the right to control the use of the power plant to the purchaser and are therefore classified as operating leases. There were no amendments to these two contracts after the Adoption Date. Included in Fuel Station Services revenues are $772 and $570 related to the lease portion of the FPAs for the three months ended March 31, 2024 and 2023, respectively. Included in Renewable Power revenues are $219 and $331 related to the lease element of the PPAs for the three months ended March 31, 2024 and 2023, respectively. Lessee contracts Ground/Site leases The Company through various of its indirectly owned subsidiaries holds site leases on landfills/dairy farms to build RNG generation facilities. Typically, the lease payments over the lease term are immaterial except for three of our RNG facilities - Beacon and two sites at our Central Valley project - MS Digester ("MS") and VS Digester ("VS"). On December 27, 2023, OPAL entered into an Amended and Restated Lease Agreement which amended the payment terms to include a minimum volume requirement that requires OPAL to pay lease payments of $1 per GGE of CNG pumped with annual minimum volumes for the lease term. The Company determined that the site lease is a finance lease because the present value of the sum of the lease payments is substantially greater than the fair value of the parcel of land. Therefore, the Company recorded right-of-use asset and related lease liability on December 27, 2023. Office lease The Company entered into a lease for office and warehouse space that became effective upon the termination of the original lease term on January 31, 2018. The term of the lease renewal was 36 months and contained an option to renew for an additional 24 months. In September 2020, the Company exercised this option. In March 2022, the Company entered into an amendment to the lease which extended the lease term till January 2026. The Company determined that the three site leases and the one office lease as operating leases. Under ASC 842, leases are classified as either finance or operating arrangements, with such classification affecting the pattern and classification of expense recognition in an entity's income statement. For operating leases, ASC 842 requires recognition in an entity’s income statement of a single lease expense, calculated so that the cost of the lease is allocated over the lease term, generally on a straight-line basis. Right-of-use assets represent a right to use an underlying asset for the lease term and the related lease liability represents an obligation to make lease payments pursuant to the contractual terms of the lease agreement. Based on the above guidance, the lease expense for the site leases is included as part of Cost of sales - RNG Fuel in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. The lease expense for the office lease is recorded as part Selling, general and administrative expenses in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. Vehicle leases The Company leases approximately 104 vehicles in our FM3 and OPAL Fuel Station Services subsidiaries. The leases contain repurchase options at the end of the lease term and the sum total of the lease payments represents substantially the fair value of the asset. Under ASC 842, the Company determined that the vehicle leases are finance leases. For finance leases, ASC 842 requires recognition of amortization of right-of-use asset as part of depreciation and amortization expense and the interest on the finance lease liability as interest expense in the income statement. The Company accordingly recognized its lease expense on the vehicle leases as part of Depreciation, amortization and accretion expense and interest and financing expense, net in its condensed statement of operations for the three months ended March 31, 2024 and 2023. Lease Disclosures Under ASC 842 The objective of the disclosure requirements under ASC 842 is to enable users of an entity’s financial statements to assess the amount, timing and uncertainty of cash flows arising from lease arrangements. In addition to the supplemental qualitative leasing disclosures included above, below are quantitative disclosures that are intended to meet the stated objective of ASC 842. Right-of-use assets and Lease liabilities as of March 31, 2024 and December 31, 2023 are as follows: Description Location in Balance Sheet March 31, 2024 December 31, 2023 Assets: Operating leases (1) : Site leases Right-of-use assets $ 11,278 $ 11,330 Office lease Right-of-use assets 859 971 12,137 12,301 Finance leases (1) : Vehicle leases Property, plant and equipment, net 2,460 2,580 Site leases Property, plant and equipment, net 6,283 6,468 8,743 9,048 Total right-of-use assets $ 20,880 $ 21,349 Liabilities (1) : Sites leases - operating Lease liabilities - current portion 138 $ 130 Office lease - operating Lease liabilities - current portion 518 508 Vehicle leases - finance Accrued expenses and other current liabilities 862 827 Site leases - finance Accrued expenses and other current liabilities 583 571 2,101 2,036 Sites leases - operating Operating lease liabilities - non-current portion 11,178 11,222 Office lease - operating Operating lease liabilities - non-current portion 468 602 Vehicle leases - finance Other long-term liabilities 1,661 1,801 Site leases - finance Other long-term liabilities $ 5,679 $ 5,587 18,986 19,212 Total lease liabilities $ 21,087 $ 21,248 (1) The Operating and Finance lease right-of-use asset and Operating and Finance lease liabilities represent the present value of lease payments for the remaining term of the lease. The discount rate used ranged from 3.59% to 8.44%. The table below presents components of the Company's lease expense for the three months ended March 31, 2024 and 2023: Description Location in Statement of Operations Three Months Ended March 31, 2024 2023 Operating lease expense for site leases Cost of sales - RNG Fuel $ 283 $ 263 Operating lease expense for office lease Selling, general, administrative expenses 121 121 Amortization of right-of-use assets - finance leases Depreciation, amortization and accretion expense 234 140 Interest expense on lease liabilities - finance leases Interest and financing expense, net 147 16 $ 785 $ 540 The Company does not have material short term lease expense for the three months ended March 31, 2024 and 2023. The Company did not enter into any operating leases greater than 12 months for the three months ended March 31, 2024. Weighted average remaining lease term (years) March 31, 2024 Operating leases 19.2 Financing leases 6.8 Weighted average discount rate Operating leases 7.85 % Financing leases 6.60 % The table below provides the total amount of lease payments on an undiscounted basis on our lease contracts as of March 31, 2024: Site leases Office leases Vehicle leases Site lease - Finance Total Weighted average discount rate 7.6 % 3.6 % 6.3 % 6.5 % 2024 $ 797 $ 406 $ 804 $ 963 $ 2,970 2025 1,129 562 966 963 3,620 2026 1,129 47 810 963 2,949 2027 1,129 — 429 963 2,521 2028 and beyond 20,310 — 5 4,250 24,565 24,494 1,015 3,014 8,102 36,625 Present value of lease liability 11,316 986 2,523 6,262 21,087 Lease liabilities - current portion 138 518 862 583 2,101 Lease liabilities - non-current portion 11,178 468 1,661 5,679 18,986 Total lease liabilities $ 11,316 $ 986 $ 2,523 $ 6,262 $ 21,087 Discount based on incremental borrowing rate $ 13,178 $ 29 $ 491 $ 1,840 $ 15,538

Derivative Financial Instrument

Derivative Financial Instruments and Fair Value Measurements	3 Months Ended
	Mar. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Financial Instruments and Fair Value Measurements	Derivative Financial Instruments and Fair Value Measurements Interest rate swaps The effect of interest rate swaps on the condensed consolidated statement of operations were as follows: Three Months Ended Location of (Loss) Gain Recognized in Operations from Derivatives 2024 2023 Swaption (1) — (66) $ — $ (66) Change in fair value of derivative instruments, net (1) The Swaption was terminated on May 30, 2023. Commodity swap contracts The Company utilizes commodity swap contracts to hedge against the unfavorable price fluctuations in market prices of electricity. The Company does not apply hedge accounting to these contracts. As such, unrealized and realized gain (loss) is recognized as a component of Renewable Power revenues in the condensed consolidated statement of operations and Derivative financial asset — current and non-current in the condensed consolidated balance sheets. These are considered to be Level 2 instruments in the fair value hierarchy. By using commodity swaps, the Company exposes itself to credit risk and market risk. Credit risk is the failure of the counter party to perform under the terms of the swap contract. When the fair value of the swap contract is positive, the counter party owes the Company creating a credit risk. The Company manages the credit risk by entering into contracts with financially sound counter parties. To mitigate this risk, management monitors counterparty credit exposure on an annual basis, and the necessary credit adjustments have been reflected in the fair value of financial derivative instruments. When the fair value of the swap contract is negative, the Company owes the counterparty creating a market risk that the market price is higher than the contract price resulting in the Company not participating in the opportunity to earn higher revenues. The Company entered into an ISDA agreement with Mendocino Capital LLC (“NextEra”), a related party in November 2019. Pursuant to the agreement, the Company entered into two additional commodity swaps in October 2022 for a period of two years with contract prices ranging between $65.50 and $68.50 per MWh. The swaps are expected to be settled by physical delivery on a monthly basis. The Company elected the normal purchase normal sale exclusion and will not apply fair value accounting under ASC 815, Derivatives and hedging . The Company will continue to assess its normal purchase and normal sale election on a quarterly basis. The Company entered into a new commodity swap with NextEra in November 2022 for a period of two years at a contract price of $81.50 per MWh. In November 2023, the Company entered into an electricity supply agreement with a utility provider for purchase of electricity to be used at one of our RNG facilities for a period of two years with a monthly notional quantity ranging between 1,875 and 2,145 Kilo watt hour and with fixed contract price $0.0599 per Kwh. The forward contract is expected to be settled by physical delivery of electricity on a monthly basis. The Company elected the normal purchase normal sale exclusion and will not apply fair value accounting under ASC 815, Derivatives and hedging . The Company will continue to assess its normal purchase and normal sale election on a quarterly basis. The following table summarizes the commodity swaps in place as of March 31, 2024 and December 31, 2023. There were no new commodity swap contracts entered during the three months ended March 31, 2024. Trade Date Period From Period To Notional Quantity per Year (“MWh”) Average Contract Price (per MWh) October 17, 2022 January 1, 2023 December 31, 2024 70,176 $ 68.50 November 17, 2022 January 1, 2023 December 31, 2024 35,088 $ 81.50 The following table summarizes the effect of commodity swaps on the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023: Derivatives not designated as hedging instruments Location of (loss) gain recognized Three Months Ended March 31, 2024 2023 Commodity swaps - realized gain Revenues - Renewable Power $ 178 $ 371 Commodity swaps - unrealized (loss) gain Revenues - Renewable Power (96) 922 Total realized and unrealized gain Revenues - Renewable Power $ 82 $ 1,293 The following table summarizes the derivative assets and liabilities related to commodity swaps as of March 31, 2024 and December 31, 2023: Fair Value Location of Fair value recognized in Balance Sheet March 31, 2024 December 31, 2023 Derivatives designated as economic hedges Current portion of unrealized gain on commodity swaps $ 537 $ 633 Derivative financial asset, current portion Other derivative liabilities On July 21, 2022, the Company recorded derivative liabilities for the outstanding public warrants and private warrants, put option to Meteora, the Sponsor Earnout Awards and the OPAL Earnout Awards. The private and public warrants were exchanged into Class A common stock in the four quarter of 2022. The put option with Meteora expired in January 2023. The change in fair value on these derivative instruments is recorded as change in fair value of derivative instruments, net in the consolidated statement of operations for the three months ended March 31, 2024 and 2023. The following table summarizes the effect of change in fair value of other derivative liabilities on the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023: Derivative liability Three Months Ended March 31, Location of (Loss) Gain Recognized in Operations from Derivatives 2024 2023 Put option to Meteora $ — $ (311) Sponsor Earnout Awards 403 310 OPAL Earnout Awards — 4,000 $ 403 $ 3,999 Change in fair value of derivative instruments, net Fair value measurements The fair value of financial instruments, including long-term debt and derivative instruments is defined as the amount at which the instruments could be exchanged in a current transaction between willing parties. The carrying amount of cash and cash equivalents, accounts receivable, net, and accounts payable and accrued expenses approximates fair value due to their short-term maturities. The carrying value of the Company's long-term debt of $194,770 and $196,542 as of March 31, 2024 and December 31, 2023, respectively, approximates its fair value because our interest rate is variable and reflects current market rates. The Company follows ASC 820, Fair Value Measurement , regarding fair value measurements which establishes a three-tier fair value hierarchy and prioritizes the inputs used in valuation techniques that measure fair value. These tiers include: Level 1 — defined as observable inputs such as quoted prices for identical instruments in active markets; Level 2 — defined as quoted prices for similar instruments in active market, quoted prices for identical or similar instruments in markets that are not active, or model-derived valuations for which all significant inputs are observable market data; Level 3 — defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company's assessment of the significance of an input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The Company values its energy commodity swap contracts based on the applicable geographical market energy forward curve. The forward curves are derived based on the quotes provided by New York Mercantile Exchange, Amerex Energy Services and Tradition Energy. The Company does not consider that the pricing index used involves significant judgement on the part of management. Therefore, the Company classifies these commodity swap contracts within Level 2 of the valuation hierarchy based on the observable market rates used to determine fair value. The Company accounts for asset retirement obligations by recording the fair value of a liability for an asset retirement obligation in the period in which it is incurred and when a reasonable estimate of fair value can be made. The Company estimates the fair value of asset retirement obligations by calculating the estimated present value of the cost to retire the asset. This estimate requires assumptions and judgments regarding the existence of liabilities, the amount and timing of cash outflows required to settle the liability, inflation factors, credit adjusted discount rates, and consideration of changes in legal, regulatory, environmental, and political environments. In addition, the Company determines the Level 3 fair value measurements based on historical information and current market conditions. These assumptions represent Level 3 inputs, which can regularly change. As such, the fair value measurement of asset retirement obligations is subject to changes in these unobservable inputs as of the measurement date. The Company used a discounted cash flow model in which cash outflows estimated to retire the asset are discounted to their present value using an expected discount rate. A significant increase (decrease) in the discount rate in isolation could result in a significantly lower (higher) fair value measurement. The Company estimated the fair value of its asset retirement obligations based on discount rates ranging from 5.75% to 8.5%. The fair value of the Sponsor Earnout Awards as of March 31, 2024 resulted in a gain of $403 due to decrease in stock price which was determined using a Monte Carlo valuation model with a distribution of potential outcomes on a daily basis over the five year post-close period. Assumptions used in the valuation are as follows: • Current stock price — The Company's closing stock price of $5.02 as of March 31, 2024; • Expected volatility — 55.0% based on historical and implied volatilities of selected industry peers deemed to be comparable to our business corresponding to the expected term of the awards; • Risk-free interest rate — 4.4% based on the U.S. Treasury yield curve in effect at the time of issuance for zero-coupon U.S. Treasury notes with maturities corresponding to the expected 3.31 year term of the earnout period; • Dividend yield - zero. The fair value of the OPAL Earnout Awards as of March 31, 2024 was determined using a Monte Carlo valuation model with a distribution of potential outcomes for stock price and EBITDA over the 2-year period commencing on January 1, 2023 and ending on December 31, 2024. As of March 31, 2024 and December 31, 2023, the fair value of OPAL Earnout Awards was determined to be zero as the probability of achieving the targets is expected to be low. Assumptions used in the valuation are as follows: • Current stock price — The Company's closing stock price of $5.02 as of March 31, 2024; • Weighted average cost of capital - 17.6% based on an average of historical volatilities of selected industry peers deemed to be comparable to our business. • Expected volatility — 45% based on historical and implied volatilities of selected industry peers deemed to be comparable to our business corresponding to the expected term of the awards; • Risk-free interest rate — 5.1% based on the U.S. Treasury yield curve in effect at the time of issuance for zero-coupon U.S. Treasury notes with maturities corresponding to the expected 9-month term of the earnout period; • Dividend yield - zero. There were no transfers of assets between Level 1, Level 2, or Level 3 of the fair value hierarchy as of March 31, 2024. The Company's assets and liabilities that are measured at fair value on a recurring basis include the following as of March 31, 2024 and December 31, 2023, set forth by level, within the fair value hierarchy: Fair value as of March 31, 2024 Level 1 Level 2 Level 3 Total Liabilities: Asset retirement obligation $ — $ — $ 6,880 $ 6,880 Earnout liabilities — — 1,497 1,497 Assets: Cash and cash equivalents and restricted cash - current and non-current (1) 32,696 — — 32,696 Short term investments 5,975 — — 5,975 Commodity swap contracts — 537 — 537 Fair value as of December 31, 2023 Level 1 Level 2 Level 3 Total Liabilities: Asset retirement obligation $ — $ — $ 6,728 $ 6,728 Earnout liabilities — — 1,900 1,900 Assets: Cash and cash equivalents and restricted cash - current and non-current (1) 47,242 — — 47,242 Short term investments 9,875 — — 9,875 Commodity swap contracts — 633 — 633 (1) Includes balances in money market accounts of $18,854 and $31,965, respectively as of March 31, 2024 and December 31, 2023. A summary of changes in the fair values of the Company’s Level 3 instruments, attributable to asset retirement obligations, for the three months ended March 31, 2024 is included in Note 2, Summary of Significant Accounting Policies .

Related Parties

Related Parties	3 Months Ended
	Mar. 31, 2024
Related Party Transactions [Abstract]
Related Parties	Related Parties Related parties are represented by Fortistar and other affiliates, subsidiaries and other entities under common control with Fortistar or NextEra. Sale of non-controlling interests to Related Parties On November 29, 2021, as part of an exchange agreement, OPAL Fuels issued 14 newly authorized common units and 300,000 Series A-1 preferred units to Hillman in return for Hillman’s non-controlling interest in four RNG project subsidiaries for total consideration of $30,000. Upon the consummation of the Business Combination, the Series A-1 preferred units have been converted to Redeemable preferred non-controlling interests. The Company recorded preferred dividend of $604 for the three months ended March 31, 2024 and a paid-in-kind dividend of $655 for the three months ended March 31, 2023. Please see Note 13. Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' Deficit, for additional information. Issuance of Redeemable preferred non-controlling interests On November 29, 2021, NextEra subscribed for up to 1,000,000 Series A preferred units, which are issuable (in whole or in increments) at the Company’s discretion prior to June 30, 2022. During the year ended December 31, 2022, the Company had drawn $100,000 and issued 1,000,000 Series A preferred units. The Company recorded preferred dividend of $2,014 for the three months ended March 31, 2024 and a paid-in-kind dividend of $2,108 for the three months ended March 31, 2023. Please see Note 13. Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' deficit , for additional information. Purchase and sale agreement for Environmental Attributes On November 29, 2021, the Company entered into a purchase and sale agreement with NextEra for the Environmental Attributes generated by the RNG Fuels business. Under this agreement, the Company plans to sell a minimum of 90% of the Environmental Attributes generated and will receive net proceeds based on the agreed upon price less a specified discount. A specified volume of Environmental Attributes sold per quarter will incur a fee per Environmental Attribute in addition to the specified discount. The agreement was effective beginning January 1, 2022. For the three months ended March 31, 2024 and 2023, the Company earned net revenues after discount and fees of $15,495 and $4,715 for RNG fuel and $7,741 and $1,493 for Fuel Station Services, respectively, under this contract which was recorded as part of Revenues - RNG fuel and Fuel Station Services. Please see Note 2. Summary of Significant Accounting Policies for additional information. Commodity swap contracts under ISDA and REC sales contracts The Company entered into an ISDA agreement with NextEra in November 2019. Pursuant to the agreement, the Company enters into commodity swap contracts on a periodic basis. As of March 31, 2024 and December 31, 2023, there were two commodity swap contracts outstanding. The Company records the realized and unrealized gain (loss) on these commodity swap contracts as part of Revenues - Renewable Power. Please see Note 9. Derivative Financial Instruments and Fair Value Measurements for additional information. Additionally, the Company has contracts to sell RECs and capacity to NextEra on multiple Renewable Power facilities at market price. The Company recorded $1,526 and $1,527 under these contracts for the three months ended March 31, 2024 and 2023. Purchase of investments from Related Parties In August 2021, the Company acquired a 100% of the ownership interests in Reynolds, an RNG production facility for $12,020 which was funded with cash on hand. Reynolds held an equity investment of 1,570 Class B units in GREP representing 20% interest for a cash consideration of $1,570 which owns 50% of Biotown, a power generation facility under development to convert to an RNG facility. The Reynolds transaction was an asset acquisition from an affiliate under common control. The Company accounts for its 20% equity investment in GREP under the equity method. The Company recorded a net loss of $71 and $203 as its share of net loss for the three months ended March 31, 2024 and 2023. Revenues contracts with equity method investment entities The Company's wholly owned subsidiary, OPAL Fuel Station Services contracted with Pine Bend in December 2020, Noble Road in March 2021, Biotown in July 2021 and Emerald in December 2021 to dispense RNG and to generate and market resulting RINs. The Company receives non-cash consideration in the form of RINs or LCFSs for providing these services and recognizes the RINs and LCFSs received as inventory based on their estimated fair value at contract inception. Additionally, OPAL Fuel Station Services provides the same services to all wholly-owned subsidiaries of the Company. The revenues earned from the wholly-owned entities are fully eliminated in the condensed consolidated financial statements. The term of this contract runs for a term of 10 years. The Company receives non-cash consideration in the form of RINs or LCFSs for providing these services and recognizes the RINs or LCFSs received as inventory based on their estimated fair value at contract inception. Pine Bend and Noble Road came online in the first and third quarter of 2022 and Emerald in the third quarter of 2023. For the three months ended March 31, 2024 and 2023, the Company earned environmental processing fees of $2,339 and $585 net of intersegment elimination, under this agreement which are included in Fuel Station Services revenues in the condensed consolidated statements of operations. Service agreements with Related Parties On December 31, 2020, OPAL Fuels signed a management, operations, and maintenance services agreement (“Administrative Services Agreement”) with Fortistar LLC ("Fortistar"), pursuant to which Fortistar provides management, operations, and maintenance services to the Company. The agreement expires on December 31, 2023 with an auto renewal option on an annual basis, unless either party chooses to terminate with a written notice of 180 days termination occurs earlier due to dissolution of the Company or the agreement is terminated by the Company’s secured lenders in certain circumstances. The agreement provides for payment of service fees based on actual time incurred at contractually agreed rates provided for in the Administrative Services Agreement, as well as a fixed annual payment of $580 per year adjusted annually for inflation. Additionally, the agreement provides for the Company to receive credits for any services provided by the Company's employees to Fortistar. For the three months ended March 31, 2024 and 2023, there have been no material services provided by the Company's employees to Fortistar. In June 2021, the company entered into a management services agreement with Costar Partners LLC (“Costar”), an affiliate of Fortistar. Pursuant to the agreement, Costar provides information technology (“IT”) support services, software use, licensing services, management of third party infrastructure and security services and additional IT services as needed by the Company. The agreement provides for Costar to be compensated based on actual costs incurred and licensing fees per user for certain software applications. The agreement expires in June 2024 unless the termination occurs earlier due to dissolution of the Company or it is terminated by the Company’s secured lenders in certain circumstances. On October 10, 2023, the board of directors of the Company appointed Mr. Scott Contino as Interim CFO. Mr. Contino has served as Fortistar's CFO for the past eighteen years. In connection with the appointment, the Company entered into an interim services agreement ("Interim Services Agreement") with Fortistar in accordance with the terms and conditions of the existing Administrative Services Agreement. Pursuant to the Interim Services Agreement, the Company will pay Fortistar an agreed hourly rate, such that the monthly fee does not exceed $50,000, on a cumulative basis. For the three months ended March 31, 2024, the Company paid $150 which is included in Selling, general and administrative expenses in the consolidated statement of operations. The following table summarizes the various fees recorded under the agreements described above which are included in "Selling, general, and administrative" expenses: Three Months Ended March 31, 2024 2023 Staffing and management services $ 462 $ 575 Rent - fixed compensation 171 165 IT services 704 726 Total $ 1,337 $ 1,466 The following table presents the various balances for related parties included in our consolidated balance sheets as of March 31, 2024 and December 31, 2023: Location in Balance Sheet March 31, 2024 December 31, 2023 Assets: Trade AR - NextEra Accounts receivable, related party $ 14,912 $ 18,696 Liabilities: Payables to equity method investment entities Accounts payable, related party 6,737 5,692 NextEra Accounts payable, related party 500 501 Staffing and management services - Fortistar Accounts payable, related party 682 622 IT services - Costar Accounts payable, related party 247 209 Total liabilities - related party $ 8,166 $ 7,024

Reportable Segments and Geograp

Reportable Segments and Geographic Information	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Reportable Segments and Geographic Information	Reportable Segments and Geographic Information The Company is organized into four operating segments based on the characteristics of its Renewable Power generation, dispensing portfolio, and the nature of other products and services. The Company changed its internal reporting to report revenues from RECs and ISCC Carbon Credits from RNG Fuel to Renewable Power segment during the third quarter of 2023. This is primarily to reflect a strategic business change to identify all revenues earned from Environmental Attributes generated from Renewable Power facilities in the same segment. Therefore, the Company reclassified revenues of $5,445 for the three months ended March 31, 2023, earned from sale of RECs and ISCC Carbon Credits from Revenues - RNG Fuel to Revenues - Renewable Power. We aligned our reportable segments disclosure to align with the information and internal reporting that is provided to our Chief Operating Decision Makers. Therefore, the Company reassessed its reportable segments and revised all the prior periods to make the segment disclosures comparable. • RNG Fuel. The RNG Fuel segment relates to all RNG supply directly related to the generation and sale of brown gas and environmental credits, and consists of: ◦ Development and construction – RNG facilities in which long term gas right contracts have been or are in the process of being ratified and the construction of RNG generation facilities. ◦ RNG supply operating facilities – This includes the generation, extraction, and sale of RNG - plus associated RINs and LCFSs from landfills. For the three months ended March 31, 2024, the Company has accounted for its interests in Pine Bend, Reynolds, Noble Road, GREP, Paragon and SJI under the equity method of accounting and the results of operations of Beacon, New River, Polk County, Cottonwood, Central Valley, Prince William and Sunoma were consolidated in its condensed consolidated statement of operations. For the three months ended March 31, 2023, the Company has accounted for its interests in Pine Bend, Reynolds, Noble Road and GREP under the equity method of accounting and the results of operations of Beacon, New River, Emerald, Sapphire, Central Valley, Prince William and Sunoma were consolidated in its condensed consolidated statement of operations. As of March 31, 2024, Central Valley, Prince William, Polk County, Cottonwood and Sapphire are not operational. • Fuel Station Services. Through its Fuel Station Services segment , t he Company provides construction and maintenance services to third-party owners of vehicle Fueling Stations and performs fuel dispensing activities including generation and minting of environmental credits. This segment includes: ◦ Service and maintenance contracts for RNG/CNG fueling sites. Includes a manufacturing division that builds Compact Fueling Systems and Defueling systems. ◦ Third Party CNG Construction of Fueling Stations - Design/build and serve as general contractor for typically Guarantee Maximum Price or fixed priced contracts for customers usually lasting less than one year. ◦ RNG and CNG fuel dispensing stations for vehicle fleets - This includes both dispensing/sale of brown gas and the environmental credit generation and monetization. The Company operates Fueling Stations that dispense gas for vehicles. This also includes the development and construction of these facilities. • Renewable Power Portfolio. The Renewable Power portfolio segment generates Renewable Power and associated environmental credits through methane-rich landfills and digester gas collection systems which is then sold to public utilities throughout the United States. The Renewable Power portfolio operates primarily in Southern California. • Corporate. This segment consists of activities managed and maintained at the Company corporate level primarily including but not limited to: ◦ Executive, accounting, finance, sales activities such as: payroll, stock compensation expense, travel and other related costs. ◦ Insurance, professional fees (audit, tax, legal etc.). The Company has determined that each of the four operating segments meets the characteristics of a reportable segment under U.S. GAAP. The Company's activities and assets that are not associated with the four reportable segments are summarized in the "Other" category below. These include corporate investment income, interest income and interest expense, income tax expense, and other non-allocated costs. Three Months Ended 2024 2023 Revenues: Renewable Power $ 10,083 $ 15,363 RNG Fuel (1) 42,792 14,288 Fuel Station Services (2) 41,650 24,575 Other (3) 342 17 Intersegment (4,508) (3,747) Equity Method Investment(s) (25,407) (7,539) $ 64,952 $ 42,957 ____________ (1) Includes revenues from our equity method investments. (2) Includes intersegment revenues eliminated in the condensed consolidated financial statements. (3) Other includes management fee revenues earned from operations and management of unconsolidated entities and Fortistar Contracting LLC. Three Months Ended 2024 2023 Interest and Financing Expense, Net: Renewable Power $ 60 $ (264) RNG Fuel (4,291) (655) Fuel Station Services 23 10 Corporate 131 202 Equity Method Investment(s) $ 116 $ 66 $ (3,961) $ (641) Three Months Ended 2024 2023 Depreciation, Amortization, and Accretion: Renewable Power $ 1,000 $ 1,452 RNG Fuel 2,346 2,024 Fuel Station Services 1,319 790 Other (1) — 16 Equity Method Investment(s) (954) (715) $ 3,711 $ 3,567 (1) Other includes amortization of intangible assets and depreciation expense not allocated to any segment. Three Months Ended 2024 2023 Net income (loss) Renewable Power $ (73) $ 4,542 RNG Fuel 2,925 (4,268) Fuel Station Services 5,722 41 Corporate (12,103) (8,366) Equity Method Investment(s) 4,206 705 $ 677 $ (7,346) Three Months Ended 2024 2023 Cash paid for Purchases of Property, Plant, and Equipment: Fuel Station Services $ 3,795 $ 5,665 RNG Fuel 22,957 33,115 $ 26,752 $ 38,780 Three Months Ended 2024 2023 Total Assets: Renewable Power $ 36,266 $ 46,199 RNG Fuel 332,204 347,591 Fuel Station Services 150,739 110,113 Corporate and other 25,276 52,229 Equity Method Investment(s) 206,014 50,570 $ 750,499 $ 606,702 Geographic Information: The Company's assets and revenue generating activities are domiciled in the United States.

Variable Interest Entities

Variable Interest Entities	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Variable Interest Entities	Variable Interest Entities We determine whether we are the primary beneficiary of a VIE upon our initial involvement with the VIE and we reassess whether we are the primary beneficiary of a VIE on an ongoing basis. Our determination of whether we are the primary beneficiary of a VIE is based upon the facts and circumstances for each VIE and requires judgment. Our considerations in determining the VIE's most significant activities and whether we have power to direct those activities include, but are not limited to, the VIE's purpose and design and the risks passed through to investors, the voting interests of the VIE, management, service and/or other agreements of the VIE, involvement in the VIE's initial design, and the existence of explicit or implicit financial guarantees. If we are the party with the power over the most significant activities, we meet the "power" criteria of the primary beneficiary. If we do not have the power over the most significant activities or we determine that all significant decisions require consent of a third-party, we do not meet the "power" criteria of the primary beneficiary. We assess our variable interests in a VIE both individually and in aggregate to determine whether we have an obligation to absorb losses of or a right to receive benefits from the VIE that could potentially be significant to the VIE. The determination of whether our variable interest is significant to the VIE requires judgment. In determining the significance of our variable interest, we consider the terms, characteristics and size of the variable interests, the design and characteristics of the VIE, our involvement in the VIE, and our market-making activities related to the variable interests. As of March 31, 2024 and December 31, 2023, the Company held equity interests in seven VIEs — Sunoma, GREP, Emerald, Sapphire, Paragon, SJI Joint Venture (RNG Atlantic and RNG Burlington) and Central Valley. As of March 31, 2024 and December 31, 2023 , GREP, Paragon and SJI were presented as equity method investments and the remaining two VIEs Sunoma and Central Valley are consolidated by the Company. In 2020, the Company acquired a variable interest in Sunoma in a joint venture with a third-party who does not have any equity at risk but participates in proportionate share of income or losses, which may be significant. Additionally, the assets in Sunoma are collateralized under the Sunoma loan, the proceeds of which are used for partial financing of the construction of the Sunoma facility. Therefore, the significant assets and liabilities of Sunoma are parenthesized in the condensed consolidated balance sheets as of March 31, 2024 and December 31, 2023. The Company determined that each of these entities are VIEs and in its capacity as a managing member except for Emerald and Sapphire, the Company is the primary beneficiary. The Company is deemed as a primary beneficiary based on two conditions: • The Company, as a managing member, has the power to order the activities that significantly impact the economic performance of the two entities including establishment of strategic, operating, and capital decisions for each of these entities; and • The Company has the obligation to absorb the potential losses for the right to receive potential benefits, which could be significant to the VIE; As a primary beneficiary, the Company consolidates these entities in accordance with the variable interest entity model guidance under ASC 810, Consolidation . Our variable interests in each of our VIEs arise primarily from our ownership of membership interests, construction commitments, our provision of operating and maintenance services, and our provision of environmental credit processing services to VIEs. The following table summarizes the major condensed consolidated balance sheet items for consolidated VIEs as of March 31, 2024 and December 31, 2023. The information below is presented on an aggregate basis based on similar risk and reward characteristics and the nature of our involvement with the VIEs, such as: • All of the VIEs are RNG facilities and they are reported under the RNG Fuel Supply segment; • The nature of our interest in these entities is primarily equity based and therefore carry similar risk and reward characteristics; The amount of assets that can only be used to settle obligations of the VIEs are parenthesized in the condensed consolidated balance sheets and are included in the asset totals listed in the table below. As of As of Assets Current assets: Cash and cash equivalents $ 1,160 $ 166 Accounts receivable, net 334 33 Restricted cash - current 1,012 4,395 Parts inventory 29 29 Prepaid expenses and other current assets 113 107 Total current assets 2,648 4,730 Property, plant and equipment, net 26,254 26,626 Restricted cash, non-current 1,957 1,850 Total assets $ 30,859 $ 33,206 Liabilities and equity Current liabilities: Accounts payable $ 11 $ 744 Accounts payable, related party 802 1,046 Accrued expenses 861 647 Other current liabilities 94 92 Sunoma Loan- current portion 1,652 1,608 Total current liabilities 3,420 4,137 Sunoma loan, net of debt issuance costs 19,609 20,010 Other long-term liabilities 1,297 211 Total liabilities 24,326 24,358 Equity Stockholders' equity 5,809 7,893 Non-redeemable non-controlling interests 724 955 Total equity 6,533 8,848 Total Liabilities and Equity $ 30,859 $ 33,206

Redeemable non-controlling inte

Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' (Deficit) Equity	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' (Deficit) Equity	Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' (Deficit) Equity Common stock As of March 31, 2024, there are (i) 30,022,288 shares of Class A common stock issued and outstanding, (ii) 71,500,000 shares of New OPAL Class B common stock issued and outstanding (shares of Class B common stock do not have any economic value except voting rights as described below), (iii) no shares of Class C common stock issued and outstanding and (iv) 72,899,037 shares of Class D common stock (shares of Class D common stock do not have any economic value except voting rights as described below). Share conversion On March 12, 2024, Fortistar, through its subsidiary OPAL Holdco, converted 71.5 million shares of Class D common stock of the Company held by it, each of which is entitled to five votes per share on all matters on which stockholders generally are entitled to vote, for an equal number of shares of newly issued Class B common stock of the Company, each of which is entitled to one vote on such matters. This transaction has no effect on the economic interest in the Company held by Fortistar or OPAL Holdco. Fortistar converted such shares in order that the Company’s Class A common stock would become eligible for inclusion in certain stock market indices, on which many broad-based mutual funds and exchange-traded index funds are based. Subsequent to the exchange, Fortistar holds 72,899,037 shares of Class D common stock and 71,500,000 shares of Class B common stock. ATM Program On November 17, 2023, OPAL Fuels Inc. (the “Company”) entered into an At The Market Issuance Sales Agreement (the “ATM Program”) with B. Riley Securities, Inc., Cantor Fitzgerald & Co. and Stifel, Nicolaus & Company, Incorporated (each, an “Agent,” and collectively, the “Agents”) pursuant to which the Company may issue and sell shares of its Class A common stock having an aggregate offering price of up to $75 million from time to time through the Agents. The Company will pay each Agent, upon the sale by such Agent of Class A common stock pursuant to the Sales Agreement, an amount equal to up to 3.0% of the gross proceeds of each such sale of Class A common stock. The Company has also provided the Agents with customary indemnification rights. The Company issued 14,005 shares of Class A common stock under the ATM Program in January 2024 at prices ranging between $5.40 and $5.68 and received net proceeds of $97. Redeemable preferred non-controlling interests On November 29, 2021, as part of an exchange agreement, the Company issued 300,000 Series A-1 preferred units to Hillman in return for Hillman’s non-controlling interest in four RNG project subsidiaries. On November 29, 2021, NextEra subscribed for up to 1,000,000 Series A preferred units, which are issuable (in whole or in increments) at the Company’s discretion prior to June 30, 2022. During the year ended December 31, 2023, the Company had drawn $100,000 and issued 1,000,000 Series A preferred units. Upon completion of Business Combination, the Company assumed Series A-1 preferred units and Series A preferred units which were issued and outstanding by OPAL Fuels. The Company recorded the Series A-1 preferred units and Series A preferred units as Redeemable preferred non-controlling interests. The Company has elected to adjust the carrying value of the preferred units to the redemption value at the end of each reporting period by immediately amortizing the issuance costs in the first reporting period after issuance of the preferred units. The following table summarizes the changes in the redeemable preferred non-controlling interests which represent Series A and Series A-1 preferred units outstanding at OPAL Fuels level from December 31, 2023 to March 31, 2024: Series A-1 preferred units Series A preferred units Units Amount Units Amount Total Balance, December 31, 2023 300,000 $ 30,604 1,000,000 $ 102,013 $ 132,617 Preferred dividends attributable to OPAL Fuels — 506 — 1,686 2,192 Preferred dividends attributable to Class A common stockholders — 98 — 328 426 Payment of Preferred dividends — (1,208) — (4,027) (5,235) Balance, March 31, 2024 300,000 $ 30,000 1,000,000 $ 100,000 $ 130,000 Terms of Redeemable preferred units The Series A and Series A-1 preferred units (together the “Preferred Units”) have substantially the same terms and features which are listed below: Voting: The Series A-1 preferred units to Hillman do not have any voting rights. The Series A preferred units issued to NextEra have limited rights to prevent the Company from taking certain actions including (i) major issuances of new debt or equity (ii) executing transactions with affiliates which are not at arm-length basis (iii) major disposition of assets and (iv) major acquisition of assets outside of the Company’s primary business. Dividends: The Preferred Units are entitled to receive dividends at the rate of 8% per annum. Dividends begin accruing for each unit from the date of issuance and are payable each quarter end regardless of whether they are declared. The dividends are mandatory and cumulative. The Company is allowed to elect to issue additional Preferred Units ( paid-in-kind) in lieu of cash for the first eight dividend payment dates. The Company elected to pay the dividends to be paid-in-kind for all periods presented. In the occurrence of certain events of default, the annual dividend rate increases to 12%. Additionally, the dividend rate increases by 2% for each unrelated uncured event of default up to a maximum of 20%. Liquidation preference: In the event of liquidation of the Company, each holder of a unit of Series A and Series A-1 is entitled to be paid on pro-rata basis the original issue price of $100 per unit plus any accrued and unpaid dividends out of the assets of the Company available for distribution after payment of the Company’s debt and liabilities and liquidation expenses. Redemption: At any time after issuance, the Company may redeem the Redeemable preferred units for a price equal to original issue price of $100 per unit plus any accrued and unpaid dividends. Holders of the Preferred Units may redeem for an amount equal to original issue price of $100 per unit plus any accrued and unpaid dividends upon (i) occurrence of certain change in control event (ii) at the end of four years from the date of issuance, except the Preferred Units issued to Hillman can only be redeemed 30 days after the fourth year anniversary of the first issuance of Preferred Units to NextEra. The maturity date is determined to be the date at which the holder’s redemption option becomes exercisable as this is the date in which both the Company and the holder may redeem the preferred units. The maturity date could be as early as November 29, 2025 but no later than June 30, 2026, depending on when the Series A units to NextEra are issued as previously detailed herein. Conversion: Holder’s may elect to convert Preferred Units into common units in the limited chance that the Company fails to redeem the Preferred Units under an optional redemption, the annual dividend rate increases to 12% and is further increased to 14% after one year, and thereafter by 2% every 90 days up to a cap of 20%. The Company must also redeem all NextEra Series A preferred units on which the redemption option has been exercised prior to redeeming any Hillman Series A-1 preferred units. If elected, the holder may convert all or a portion of its Preferred Units into a number of common units equal to: (i) number of Preferred Units, multiplied by, (ii) $100 plus accrued and unpaid cash dividends, divided by, (iii) conversion price. The conversion price is equal to the value of the Company’s common units determined as follows, and reduced by a 20% discount if conversion occurs during the first year of delayed redemption, a 25% discount during the 2nd year, and a 30% discount thereafter: 1. Using 20-day volume-weighted average price (“VWAP”) of the Company's common shares. 2. Otherwise the estimated proceeds to be received by the holder of a common unit if the net assets of the Company were sold at fair market value and distributed. Redeemable non-controlling interests Upon consummation of Business Combination, OPAL Fuels and its members caused the existing limited liability company agreement to be amended and restated and in connection therewith, all of the common units of OPAL Fuels LLC issued and outstanding immediately prior to the closing were re-classified into 144,399,037 Class B Units. Each Class B Unit is paired with 1 non-economic share of Class D common stock issued by the Company. Each pair of Class B Unit and 1 share of Class D common stock is exchangeable to either 1 share of Class A common stock or 1 share of Class C common stock at the holder's option. Upon an exchange for Class A common stock, the Company has the option to redeem shares for cash at their market value.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Net Income (Loss) Per Share The basic income (loss) per share of Class A common stock is computed by dividing the net loss attributable to Class A common stockholders by the weighted average number of Class A common stock outstanding during the period. The basic income (loss) per share for the three months ended March 31, 2024 and 2023 does not include 1,635,783 shares in treasury, 763,908 shares issued and outstanding but are contingent on achieving earnout targets. During the first quarter of 2023, the put option was exercised and 197,258 shares of Class A common stock were cancelled. The diluted income per share of Class A common stock for the three months ended March 31, 2024 does not include Redeemable preferred non-controlling interests because the substantive contingency for conversion has not been met as of March 31, 2024. It does not include 144,399,037 OPAL Fuels Class B units representing Redeemable non-controlling interest as its impact is anti-dilutive. It does not include 716,650 Sponsor Earnout Awards and 10,000,000 OPAL Earnout Awards as their target share price and adjusted EBITDA contingencies have not been met as of March 31, 2024. The outstanding restricted stock units and stock options issued under the 2022 Plan are not included as their impact is antidilutive. The outstanding performance units under the 2022 Plan are not included as the performance conditions have not been met as of March 31, 2024. The diluted loss per share of Class A common stock for the three months ended March 31, 2023 does not include Redeemable preferred non-controlling interests, Convertible Note Payable because the substantive contingency for conversion has not been met as of March 31, 2023. It does not include 144,399,037 OPAL Fuels Class B units representing Redeemable non-controlling interest as its impact is anti-dilutive. It does not include 763,908 Sponsor Earnout Awards and 10,000,000 OPAL Earnout Awards as their target share price and adjusted EBITDA contingencies have not been met as of March 31, 2023. The outstanding restricted stock units, stock options and performance units issued under the 2022 Plan are not included as their impact is dilutive. The Class B common stock and D common stock do not participate in the earnings or losses of the Company and are therefore not participating securities. As such, separate presentation of basic and diluted earnings per share of Class B common stock and Class D common stock under the two-class method has not been presented. The following table summarizes the calculation of basic and diluted net loss per share: Three Months Ended 2024 2023 Net loss attributable to Class A common stockholders $ (316) $ (1,579) Weighted average number of shares of Class A common stock - basic 27,368,204 27,383,562 Dilutive effect of stock options, restricted stock units, performance units, Convertible note payable, earnout shares, Redeemable preferred non-controlling interests, Redeemable non-controlling interests — — Weighted average number of shares of Class A common stock - diluted 27,368,204 27,383,562 Net loss per share of Class A common stock Basic $ (0.01) $ (0.06) Diluted $ (0.01) $ (0.06)

Income taxes

Income taxes	3 Months Ended
	Mar. 31, 2024
Income Tax Disclosure [Abstract]
Income taxes	Income taxes As a result of the Company’s up-C structure effective with the Business Combination, the Company expects to be a tax-paying entity. However, as the Company has historically been loss-making, any deferred tax assets created as a result of net operating losses and other deferred tax assets for the excess of tax basis in the Company's investment in Opal Fuels would be offset by a full valuation allowance. Prior to the Business Combination, OPAL Fuels was organized as a limited liability company, with the exception of one partially-owned subsidiary which filed income tax returns as a C-Corporation. The Company accounts for its income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to the differences between the financial statement carrying amount of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in earnings in the period that includes the enactment date. Judgment is required in determining the provisions for income and other taxes and related accruals, and deferred tax assets and liabilities. In the ordinary course of business, there are transactions and calculations where the ultimate tax outcome is uncertain. Additionally, the Company's various tax returns are subject to audit by various tax authorities. Although the Company believes that its estimates are reasonable, actual results could differ from these estimates. For the three months ended March 31, 2024 and 2023, the Company recorded zero income tax expense. The effective tax rate for the three months ended March 31, 2024 and 2023 was 0%. The difference between the Company’s effective tax rate and the U.S. statutory tax rate of 21% was primarily due to a full valuation allowance recorded on the Company’s net U.S. deferred tax assets. The Company evaluates the realizability of the deferred tax assets on a quarterly basis and establishes a valuation allowance when it is more likely than not that all or a portion of a deferred tax asset may not be realized.

Stock-based compensation

Stock-based compensation	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Stock-based compensation	Stock-based compensation 2022 Omnibus Equity Incentive Plan The Company adopted 2022 Omnibus Equity Incentive Plan (the "2022 Plan") in 2022 which was approved by our shareholders on July 21, 2022. The purposes of the 2022 Plan is to (i) provide an additional incentive to selected employees, directors, and independent contractors of the Company or its Affiliates whose contributions are essential to the growth and success of the Company, (ii) strengthen the commitment of such individuals to the Company and its Affiliates, (iii) motivate those individuals to faithfully and diligently perform their responsibilities and (iv) attract and retain competent and dedicated individuals whose efforts will result in the long-term growth and profitability of the Company. The 2022 Plan allows for granting of stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards. The Company registered 19,811,726 shares of Class A common stock that can be issued under this Plan. During the three months ended March 31, 2024, the Company issued 360,298 stock options, 1,110,031 restricted stock units and 456,308 performance units to certain employees of the Company. The applicable performance period for such performance units is January 1, 2024 to December 31, 2026, and all such performance units are scheduled to vest on March 31, 2026 subject to achievement of certain performance criteria. The fair value of the stock options was determined to be $3.40 based on Black Scholes model based on the share price of $4.96, exercise price of $5.02, expiration of 10 years, annual risk free interest rate of 3.96% and volatility of 55%. Additionally, the Company issued 190,526 restricted stock units to the board of directors which vest 100% on their first anniversary. The total fair value of the equity awards was $9,971. A summary of the equity awards under the 2022 Plan for the three months ended March 31, 2024 is as follows: Restricted stock units Weighted average fair value per restricted unit on grant date Exercise price per Stock Option Aggregate fair value Vesting terms Restricted Stock Units: Unvested restricted stock units outstanding as of December 31, 2023 949,936 $ 6.98 $ — $ 6,627 Equal installments vesting over one Granted during the quarter ending March 31, 2024 1,300,557 4.98 — 6,479 Equal installments vesting over one Vested during 2024 (307,137) 6.97 — (2,141) Withheld for settlement of taxes (112,402) 6.97 — (783) Forfeitures during 2024 (2,870) 6.97 — (20) Unvested restricted stock units outstanding at March 31, 2024 1,828,084 $ 5.56 $ — $ 10,162 Stock Options: (1) Outstanding awards as of December 31, 2023 175,890 $ 5.26 $ 6.97 $ 925 Three equal installments vesting over three years Granted in March 2024 360,298 3.40 5.02 1,225 Three equal installments vesting over three years Outstanding Stock Options at March 31, 2024 536,188 $ 4.01 $ 5.66 2,150 Options vested and exercisable as of March 31, 2024 62,327 5.26 6.97 328 Performance Stock Units: Unvested awards as of December 31, 2023 239,680 6.97 — $ 1,671 100% vesting on March 31, 2026 Granted in March 2024 456,308 4.97 — 2,267 100% vesting on March 31, 2027 Forfeitures during 2024 (1,865) 6.97 — (13) Performance Stock Units outstanding as of March 31, 2024 694,123 $ 5.65 $ — $ 3,925 Total unvested awards outstanding as of March 31, 2024 3,120,722 $ 5.31 16,565 (1) Stock options have an expiration term of 10-years. As of March 31, 2024 and December 31, 2023, there are 62,327 and 0, respectively, of stock options vested and exercisable at exercise price shown above. The aggregate intrinsic value of the outstanding stock options is zero as of March 31, 2024 and December 31, 2023. The stock-based compensation expense for the above stock awards under the 2022 Plan as well as Parent Equity Awards is included in the selling, general and administrative expenses: Three Months Ended March 31, 2024 2023 2022 Plan $ 853 $ 811 Parent equity awards 160 160 $ 1,013 $ 971

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Letters of Credit As of March 31, 2024 and December 31, 2023, the Company was required to maintain eleven standby letters of credit totaling $14,637 and $14,783, respectively, to support obligations of certain Company subsidiaries. These letters of credit were issued in favor of a lender, utilities, a governmental agency, and an independent system operator under PPA electrical interconnection agreements, and in place of a debt service reserve. There have been no draws to date on these letters of credit. Purchase Options The Company has two contracts with customers to provide CNG for periods of seven In July 2015, the Company entered into a ten year fuel sales agreement with a customer that included the construction of a CNG Fueling Station owned and managed by the Company on the customer's premises. At the end of the contract term, the customer has an option to purchase the CNG Fueling Station for a fixed amount. The cost of the CNG Fueling Station was recorded to Property, plant, and equipment and is being depreciated over the contract term. On May 30, 2023, OPAL Intermediate Holdco 2 assigned to Paragon its rights and obligations under the OPAL Term Loan II. Legal Matters The Company is involved in various claims arising in the normal course of business. Management believes that the outcome of these claims will not have a material adverse effect on the Company's financial position, results of operations or cash flows. Set forth below is information related to the Company’s material pending legal proceedings as of the date of this report, other than ordinary routine litigation incidental to the business. Central Valley Project In September 2021, an indirect subsidiary of the Company, MD Digester, LLC, entered into a fixed-price Engineering, Procurement and Construction Contract (an “EPC Contract”) with VEC Partners, Inc. d/b/a CEI Builders (“Contractor”) for the design and construction of a turn-key renewable natural gas production facility using dairy cow manure as feedstock. In December 2021, a second indirect subsidiary of the Company, VS Digester, LLC entered into a nearly identical EPC Contract with Contractor for the design and construction of a second facility in connection with the same project. Contractor has submitted a series of change order requests seeking to increase the EPC Contract price under each contract by approximately $14 million (i.e., approximately $28 million in total), primarily due to modifications to Contractor’s design drawings that are required to meet its contracted performance guaranties and a termination (for default) of one of Contractor’s major equipment manufacturers. The Company disputes substantially all of the change order requests. On January 5, 2024, the Company filed a civil lawsuit captioned, MD Digester, LLC. et. al. vs. VEC Partners, Inc. et. al.; California Superior Court, County of San Joaquin; Action No. STK-CV-UCC-2024-0000185 and commenced a related arbitration proceeding in order to obtain a formal determination on the claims, AAA Case No. 01-24-0000-0775. The Superior Court Action will be stayed, pending an award in the AAA proceeding. The AAA proceeding has not been set for hearing. Each of the Parties have nominated one arbitrator (each a "Party-selected Arbitrator") and a third arbitrator was appointed by the Party-selected Arbitrators to chair the panel. As a result of the procedural status of these matters, no discovery has occurred. The EPC Agreement provides that Contractor is obligated to continue working during the course of the litigation and related arbitration proceedings. Contractor’s performance under both of the EPC Contracts is fully bonded by licensed sureties. Despite informal settlement discussions with Contractor, the parties have not been able as of yet to resolve the claims. The Company believes its claims against Contractor have substantial merit and intends to prosecute its claims vigorously. However, due to the incipient stage of the litigation and related arbitration, its ongoing status, and the uncertainties involved in all litigation and arbitration, the Company does not believe it is feasible at this time to assess the likely outcome of the litigation and related arbitration, the timing of its resolution, or its ultimate impact on the Central Valley projects or the Company's business, financial condition or results of operations.

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Mar. 31, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Basis of Presentation and Principles of Consolidation	Basis of Presentation and Principles of Consolidation These condensed consolidated financial statements are prepared in accordance with generally accepted accounting principles in the United States ("U.S. GAAP") and include the accounts of the Company and all other entities in which the Company has a controlling financial interest: OPAL Renewable Power LLC (formerly Fortistar Methane 3 LLC (“FM3”) and Fortistar Methane 4 LLC), Beacon RNG LLC (“Beacon”) Sunoma Holdings, LLC (“Sunoma”), New River LLC (“New River”), Reynolds RNG LLC (“Reynolds”), Central Valley LLC (“Central Valley”), Prince William RNG LLC (“Prince William”), Cottonwood RNG LLC, Polk County RNG LLC (“Polk County”), OPAL Contracting LLC (formerly Fortistar Contracting LLC), OPAL RNG LLC (formerly Fortistar RNG LLC), and OPAL Fuel station services LLC (“Fuel Station Services”). The Company’s unaudited condensed consolidated financial statements include the assets and liabilities of these subsidiaries. All intercompany transactions and balances have been eliminated in consolidation. The non-controlling interest attributable to the Company's variable interest entities ("VIE") are presented as a separate component from the Stockholders' deficit in the condensed consolidated balance sheets and as a non-redeemable non-controlling interests in the condensed consolidated statements of changes in redeemable non-controlling interests, redeemable preferred non-controlling interests and Stockholders' (deficit) equity. Certain prior period amounts have been reclassified to conform with the current period presentation including reclassification of the Company’s proportional share of income in equity investments into operating income. See Note 3. Investment in Other Entities for further discussion. The Company reclassified certain project development and start up costs as a separate line within Operating expenses, which were previously included in Cost of sales - RNG Fuel and Selling, general and administrative expenses. Please see the Project development and start up costs section within Note 2. Additionally, the Company also reclassified certain Asset retirement obligations from current to non-current. The information included in this quarterly report should be read in conjunction with the Company's audited consolidated financial statements and notes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2023 as the interim disclosures generally do not repeat those in the annual financial statements. In the opinion of management, the Company's financial statements include all normal and recurring adjustments necessary in order to make the financial statements not misleading and to provide a fair presentation of the Company's financial results for the interim periods included in this Quarterly Report.
Variable Interest Entities	Variable Interest Entities Our policy is to consolidate all entities that we control by ownership of a majority of the outstanding voting stock. In addition, we consolidate entities that meet the definition of a VIE for which we are the primary beneficiary. The Company applies the VIE model from ASC 810 when the Company has a variable interest in a legal entity not subject to a scope exception and the entity meets any of the five characteristics of a VIE. The primary beneficiary of a VIE is considered to be the party that both possesses the power to direct the activities of the entity that most significantly impact the entity’s economic performance and has the obligation to absorb losses or the rights to receive benefits of the VIE that could be significant to the VIE. To the extent a VIE is not consolidated, the Company evaluates its interest for application of the equity method of accounting. Equity method investments are included in the condensed consolidated balance sheets as “Investments in other entities.” Investments in unconsolidated entities in which the Company has influence over the operating or financial decisions are accounted for under the equity method. We determine whether we are the primary beneficiary of a VIE upon our initial involvement with the VIE and we reassess whether we are the primary beneficiary of a VIE on an ongoing basis. Our determination of whether we are the primary beneficiary of a VIE is based upon the facts and circumstances for each VIE and requires judgment. Our considerations in determining the VIE's most significant activities and whether we have power to direct those activities include, but are not limited to, the VIE's purpose and design and the risks passed through to investors, the voting interests of the VIE, management, service and/or other agreements of the VIE, involvement in the VIE's initial design, and the existence of explicit or implicit financial guarantees. If we are the party with the power over the most significant activities, we meet the "power" criteria of the primary beneficiary. If we do not have the power over the most significant activities or we determine that all significant decisions require consent of a third-party, we do not meet the "power" criteria of the primary beneficiary. We assess our variable interests in a VIE both individually and in aggregate to determine whether we have an obligation to absorb losses of or a right to receive benefits from the VIE that could potentially be significant to the VIE. The determination of whether our variable interest is significant to the VIE requires judgment. In determining the significance of our variable interest, we consider the terms, characteristics and size of the variable interests, the design and characteristics of the VIE, our involvement in the VIE, and our market-making activities related to the variable interests.
Use of estimates	Use of estimates The preparation of condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The significant estimates and assumptions of the Company include the residual value of the useful lives of our property, plant and equipment, the fair value of stock-based compensation, asset retirement obligations, the estimated losses on our trade receivables, percentage completion for revenue recognition, incremental borrowing rate for calculating the right-of-use lease assets and lease liabilities, the impairment assessment of goodwill and the fair value of derivative instruments. Actual results could differ from those estimates. The results of operations for the interim periods presented are not necessarily indicative of the results that may be expected for the entire year.
Accounting Pronouncements Not Yet Adopted	Accounting Pronouncements Not Yet Adopted
Short term investments	Short term investments The Company considers highly liquid investments such as time deposits and certificates of deposit with an original maturity greater than three months at the time of purchase to be short term investments. The Short term investments of $5,975 and $9,875 as of March 31, 2024 and December 31, 2023, respectively, consists of cash invested in commercial paper with maturities ranging between 1 and 12 months as of the reporting date. The amounts in these accounts are liquid and available for general use. Our short term investments are generally invested in commercial paper issued by highly credit worthy counter parties and government backed treasury bills. Investments are generally not FDIC insured and we take counter party risk on these investments.
Earnout Liabilities	Earnout Liabilities
Redeemable non-controlling interests	Redeemable non-controlling interests Redeemable non-controlling interests represent the portion of OPAL Fuels that the Company controls and consolidates but does not own. The Redeemable non-controlling interest was created as a result of the Business Combination and represents 144,399,037 Class B Units issued by OPAL Fuels to the prior investors. The Company allocates net income or loss attributable to Redeemable non-controlling interest based on weighted average ownership interest during the period. The net income or loss attributable to Redeemable non-controlling interests is reflected in the condensed consolidated statement of operations.
Project development and start up costs	Project development and start up costs
Net loss per share	Net loss per share The Company's basic earnings per share of Class A common stock is computed based on the average number of outstanding shares of Class A common stock for the period.
Asset Retirement Obligation	Asset Retirement Obligation The Company accounts for asset retirement obligations in accordance with FASB ASC 410, Asset Retirement and Environmental Obligations, which requires entities to record the fair value of a liability for an asset retirement obligation in the period in which it is incurred and when a reasonable estimate of fair value can be made. The fair value of the estimated asset retirement obligations is recorded as a long-term liability, with a corresponding increase in the carrying amount of the related asset. The discounted asset retirement costs capitalized amount are accreted over the life of the sublease or site lease agreement. Asset retirement obligations are deemed Level 3 fair value measurements as the inputs used to measure the fair value are unobservable. The Company estimates the fair value of asset retirement obligations by calculating the estimated present value of the cost to retire the asset. This estimate requires assumptions and judgments regarding the existence of liabilities, the amount and timing of cash outflows required to settle the liability, inflation factors, credit adjusted discount rates, and consideration of changes in legal, regulatory, environmental, and political environments. In addition, the Company determines the Level 3 fair value measurements based on historical information and current market conditions.
Revenue Recognition	Revenue Recognition The Company’s revenue arrangements generally consist of a single performance obligation to transfer goods or services. Revenue from the sale of RNG, CNG and electricity is recognized by applying the “right to invoice” practical expedient within the accounting guidance for Revenue from Contracts with Customers that allows for the recognition of revenue from performance obligations in the amount of consideration to which there is a right to invoice the customer and when the amount for which there is a right to invoice corresponds directly to the value transferred to the customer. For some public CNG Fueling Stations where there is no contract with the customer, the Company recognizes revenue at the point in time that the customer takes control of the fuel. The Company also performs maintenance services throughout the country. Maintenance consists of monitoring equipment and replacing parts as necessary to ensure optimum performance. Revenue from service agreements is recognized over time as services are provided. Capacity payments fluctuate based on peak times of the year and revenues from capacity payments are recognized monthly as earned. The Company has agreements with two natural gas producers ("Producers") to transport Producers' natural gas using the Company's RNG gathering system. The performance obligation is the delivery of Producers' natural gas to an agreed delivery point on an interstate gas pipeline. The quantity of natural gas transported for the Producers is measured at a certain specified meter. The price is fixed at contracted rates and the Producers pay approximately 30 days after month-end. As such, transportation sales are recognized over time, using the output method to measure progress. The Company provides credit monetization services to customers that own renewable gas generation facilities. The Company recognizes revenue from these services as the credits are minted on behalf of the customer. The Company receives non-cash consideration in the form of RINs or LCFSs for providing these services and recognizes the RINs or LCFSs received as Environmental credits held for sale within current assets based on their estimated fair value at contract inception. On November 29, 2021, the Company entered into a purchase and sale agreement with NextEra, a related party, for the Environmental Attributes generated by the RNG Fuels business. Under this agreement, the Company is committed to sell a minimum of 90% of the Environmental Attributes generated and will receive net proceeds based on the agreed upon price less a specified discount. A specified volume of Environmental Attributes sold per quarter will incur a discount fee per Environmental Attribute in addition to the specified discount. The agreement was effective beginning January 1, 2022. For the three months ended March 31, 2024 and 2023, the Company earned net revenues after discount and fees of $15,495 and $4,715, respectively, under this contract which was recorded as part of Revenues - RNG Fuel. For the three months ended March 31, 2024 and 2023, the Company earned net revenues after discount and fees of $7,741 and $1,493, respectively, which was recorded as part of Revenues - Fuel Station Services. During third and fourth quarter of 2022, two of the wholly-owned subsidiaries from our Renewable Power portfolio entered into a purchase and sale agreement with an Environmental Attribute marketing firm to sell Environmental Attributes associated with renewable biomethane ("ISCC Carbon Credits") and purchase brown gas back at contracted fixed prices per million British thermal units ("MMbtu"). One of these contracts has a term of 3-years from the date of certification of the facility with an auto-renewal option. The other contract was terminated in August 2023. During the third quarter of 2023, three additional Renewable Power facilities entered into purchase and sale agreements with 3-year terms and similar terms and conditions as the previous contracts. For the three months ended March 31, 2024 and 2023, the Company earned net revenues of $3,788 and $5,445, respectively under the contracts which were recorded as part of Revenues - Renewable Power in the condensed consolidated statement of operations. Sales of Environmental Attributes such as RINs, renewable energy credits ("RECs"), ISCC Carbon Credits and LCFS are generally recorded as revenue when the certificates related to them are delivered to a buyer. However, the Company may recognize revenue from the sale of such Environmental Attributes at the time of the related Renewable Power sales when the contract provides that title to the Environmental Attributes transfers at the time of production, the Company's price to the buyer is fixed, and collection of the sales proceeds is certain. Management operating fees are earned for the operation, maintenance, and repair of the gas collection system of a landfill site. Revenue is calculated on the volume of per million British thermal units of LFG collected and the megawatt hours ("MWhs") produced at that site. This revenue is recognized when LFG is collected and Renewable Power is delivered. The Company has various fixed price contracts for the construction of Fueling Stations for customers. Revenues from these contracts, including change orders, are recognized over time, with progress measured by the percentage of costs incurred to date compared to estimated total costs for each contract. This method is used as management considers costs incurred to be the best available measure of progress on these contracts. Costs capitalized to fulfill certain contracts were not material in any of the periods presented. The Company owns Fueling Stations for use by customers under fuel sale agreements. The Company bills these customers at an agreed upon price for each gallon sold and recognizes revenue based on the amounts invoiced in accordance with the "right to invoice" practical expedient. For some public stations where there is no contract with the customer, the Company recognizes revenue at the point-in-time that the customer takes control of the fuel. The Company from time-to-time enters into fuel purchase agreements with customers whereby the Company is contracted to design and build a Fueling Station on the customer's property in exchange for the Company providing CNG/RNG to the customer for a determined number of years. In accordance with the standards of ASC 840, Leases , the Company has concluded these agreements meet the criteria for a lease and are classified as operating leases. Typically, these agreements do not require any minimum consumption amounts and, therefore, no minimum payments. Upon adoption of ASC 842, the Company adopted the practical expedient not to reassess the classification. For additional information on lease revenues earned, please see Note 8. Leases.
Environmental credits held for sale	Environmental credits held for sale
Major Maintenance	Major Maintenance
Vulnerability Due to Certain Concentrations	Vulnerability Due to Certain Concentrations Financial instruments that potentially subject the Company to concentration of credit risk consist principally of cash, cash equivalents, restricted cash, short term investments, derivative instruments and trade accounts receivable. The Company holds cash, cash equivalents and restricted cash at several major financial institutions, much of which exceeds FDIC insured limits. Historically, the Company has not experienced any losses due to such concentration of credit risk. The Company’s temporary cash investments policy is to limit the dollar amount of investments with any one financial institution and monitor the credit ratings of those institutions. While the Company may be exposed to credit losses due to the nonperformance of the holders of its deposits, the Company does not expect the settlement of these transactions to have a material effect on its results of operations, cash flows or financial condition. Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash and cash equivalents, and trade receivables. The Company places its cash with high credit quality financial institutions located in the United States of America. The Company performs ongoing credit evaluations of its customers.
Income Taxes	Income Taxes The Company accounts for income taxes in accordance with ASC Topic 740, Accounting for Income Taxes (“ASC Topic 740”), which requires the recognition of tax benefits or expenses on temporary differences between the financial reporting and tax bases of its assets and liabilities by applying the enacted tax rates in effect for the year in which the differences are expected to reverse. Such net tax effects on temporary differences are reflected on the Company’s condensed consolidated balance sheets as deferred tax assets and liabilities. Deferred tax assets are reduced by a valuation allowance when the Company believes that it is more-likely-than-not that some portion or all of the deferred tax assets will not be realized. The Company calculates the interim tax provision in accordance with the provisions of ASC Subtopic 740-270, Income Taxes; Interim Reporting. For interim periods, the Company estimates the annual effective income tax rate and applies the estimated rate to the year-to-date income or loss before income taxes. of existing assets and liabilities and their respective tax basis and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the year in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in earnings in the period that includes the enactment date. Judgment is required in determining the provisions for income and other taxes and related accruals, and deferred tax assets and liabilities. In the ordinary course of business, there are transactions and calculations where the ultimate tax outcome is uncertain. Additionally, the Company's various tax returns are subject to audit by various tax authorities. Although the Company believes that its estimates are reasonable, actual results could differ from these estimates.
Investment in other entities	The Company uses the equity method to account for investments in affiliates that it does not control, but in which it has the ability to exercise significant influence over operating and financial policies. The Company's investments in these nonconsolidated affiliates are reflected in the Company's condensed consolidated balance sheets under the equity method, and the Company's proportionate net income, if any, is included in the Company's condensed consolidated statements of operations as income from equity method investments. We continue to evaluate operational developments and the impact of the anticipated expansion of the operations of our existing equity method investments. Based on our analysis, it was determined that our equity method investments have evolved into a critical, integral part of our RNG segment business operations as they provide critical additional production capacity. Therefore, we have determined that the presentation of income (loss) from equity method investments as part of the operating income is more meaningful and useful information to the readers of our financial statements. As a result, we have reclassified our portion of income (loss) from equity method investments to Operating income for all periods presented.
Leases	Leases The following are the type of contracts that fall under ASC 842: Lessor contracts Fuel Provider agreements Fuel provider agreements ("FPAs") are for the sale of brown gas, service and maintenance of sites. The Company is contracted to design and build a Fueling Station on the customer's property in exchange for the Company providing CNG/RNG to the customer for a determined number of years. These are considered to be operating leases with variable consideration. As per ASC 842, the revenue is recognized in the period earned. Power Purchase agreements Power purchase agreements ("PPAs") are for the sale of electricity generated at our Renewable Power facilities. All of our Renewable Power facilities operate under fixed pricing or indexed pricing based on market prices. Two of our Renewable Power facilities transfer the right to control the use of the power plant to the purchaser and are therefore classified as operating leases. There were no amendments to these two contracts after the Adoption Date. Included in Fuel Station Services revenues are $772 and $570 related to the lease portion of the FPAs for the three months ended March 31, 2024 and 2023, respectively. Included in Renewable Power revenues are $219 and $331 related to the lease element of the PPAs for the three months ended March 31, 2024 and 2023, respectively. Lessee contracts Ground/Site leases The Company through various of its indirectly owned subsidiaries holds site leases on landfills/dairy farms to build RNG generation facilities. Typically, the lease payments over the lease term are immaterial except for three of our RNG facilities - Beacon and two sites at our Central Valley project - MS Digester ("MS") and VS Digester ("VS"). On December 27, 2023, OPAL entered into an Amended and Restated Lease Agreement which amended the payment terms to include a minimum volume requirement that requires OPAL to pay lease payments of $1 per GGE of CNG pumped with annual minimum volumes for the lease term. The Company determined that the site lease is a finance lease because the present value of the sum of the lease payments is substantially greater than the fair value of the parcel of land. Therefore, the Company recorded right-of-use asset and related lease liability on December 27, 2023. Office lease The Company entered into a lease for office and warehouse space that became effective upon the termination of the original lease term on January 31, 2018. The term of the lease renewal was 36 months and contained an option to renew for an additional 24 months. In September 2020, the Company exercised this option. In March 2022, the Company entered into an amendment to the lease which extended the lease term till January 2026. The Company determined that the three site leases and the one office lease as operating leases. Under ASC 842, leases are classified as either finance or operating arrangements, with such classification affecting the pattern and classification of expense recognition in an entity's income statement. For operating leases, ASC 842 requires recognition in an entity’s income statement of a single lease expense, calculated so that the cost of the lease is allocated over the lease term, generally on a straight-line basis. Right-of-use assets represent a right to use an underlying asset for the lease term and the related lease liability represents an obligation to make lease payments pursuant to the contractual terms of the lease agreement. Based on the above guidance, the lease expense for the site leases is included as part of Cost of sales - RNG Fuel in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. The lease expense for the office lease is recorded as part Selling, general and administrative expenses in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. Vehicle leases The Company leases approximately 104 vehicles in our FM3 and OPAL Fuel Station Services subsidiaries. The leases contain repurchase options at the end of the lease term and the sum total of the lease payments represents substantially the fair value of the asset. Under ASC 842, the Company determined that the vehicle leases are finance leases. For finance leases, ASC 842 requires recognition of amortization of right-of-use asset as part of depreciation and amortization expense and the interest on the finance lease liability as interest expense in the income statement. The Company accordingly recognized its lease expense on the vehicle leases as part of Depreciation, amortization and accretion expense and interest and financing expense, net in its condensed statement of operations for the three months ended March 31, 2024 and 2023. Lease Disclosures Under ASC 842 The objective of the disclosure requirements under ASC 842 is to enable users of an entity’s financial statements to assess the amount, timing and uncertainty of cash flows arising from lease arrangements. In addition to the supplemental qualitative leasing disclosures included above, below are quantitative disclosures that are intended to meet the stated objective of ASC 842.
Leases	Leases The following are the type of contracts that fall under ASC 842: Lessor contracts Fuel Provider agreements Fuel provider agreements ("FPAs") are for the sale of brown gas, service and maintenance of sites. The Company is contracted to design and build a Fueling Station on the customer's property in exchange for the Company providing CNG/RNG to the customer for a determined number of years. These are considered to be operating leases with variable consideration. As per ASC 842, the revenue is recognized in the period earned. Power Purchase agreements Power purchase agreements ("PPAs") are for the sale of electricity generated at our Renewable Power facilities. All of our Renewable Power facilities operate under fixed pricing or indexed pricing based on market prices. Two of our Renewable Power facilities transfer the right to control the use of the power plant to the purchaser and are therefore classified as operating leases. There were no amendments to these two contracts after the Adoption Date. Included in Fuel Station Services revenues are $772 and $570 related to the lease portion of the FPAs for the three months ended March 31, 2024 and 2023, respectively. Included in Renewable Power revenues are $219 and $331 related to the lease element of the PPAs for the three months ended March 31, 2024 and 2023, respectively. Lessee contracts Ground/Site leases The Company through various of its indirectly owned subsidiaries holds site leases on landfills/dairy farms to build RNG generation facilities. Typically, the lease payments over the lease term are immaterial except for three of our RNG facilities - Beacon and two sites at our Central Valley project - MS Digester ("MS") and VS Digester ("VS"). On December 27, 2023, OPAL entered into an Amended and Restated Lease Agreement which amended the payment terms to include a minimum volume requirement that requires OPAL to pay lease payments of $1 per GGE of CNG pumped with annual minimum volumes for the lease term. The Company determined that the site lease is a finance lease because the present value of the sum of the lease payments is substantially greater than the fair value of the parcel of land. Therefore, the Company recorded right-of-use asset and related lease liability on December 27, 2023. Office lease The Company entered into a lease for office and warehouse space that became effective upon the termination of the original lease term on January 31, 2018. The term of the lease renewal was 36 months and contained an option to renew for an additional 24 months. In September 2020, the Company exercised this option. In March 2022, the Company entered into an amendment to the lease which extended the lease term till January 2026. The Company determined that the three site leases and the one office lease as operating leases. Under ASC 842, leases are classified as either finance or operating arrangements, with such classification affecting the pattern and classification of expense recognition in an entity's income statement. For operating leases, ASC 842 requires recognition in an entity’s income statement of a single lease expense, calculated so that the cost of the lease is allocated over the lease term, generally on a straight-line basis. Right-of-use assets represent a right to use an underlying asset for the lease term and the related lease liability represents an obligation to make lease payments pursuant to the contractual terms of the lease agreement. Based on the above guidance, the lease expense for the site leases is included as part of Cost of sales - RNG Fuel in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. The lease expense for the office lease is recorded as part Selling, general and administrative expenses in its condensed consolidated statement of operations for the three months ended March 31, 2024 and 2023. Vehicle leases The Company leases approximately 104 vehicles in our FM3 and OPAL Fuel Station Services subsidiaries. The leases contain repurchase options at the end of the lease term and the sum total of the lease payments represents substantially the fair value of the asset. Under ASC 842, the Company determined that the vehicle leases are finance leases. For finance leases, ASC 842 requires recognition of amortization of right-of-use asset as part of depreciation and amortization expense and the interest on the finance lease liability as interest expense in the income statement. The Company accordingly recognized its lease expense on the vehicle leases as part of Depreciation, amortization and accretion expense and interest and financing expense, net in its condensed statement of operations for the three months ended March 31, 2024 and 2023. Lease Disclosures Under ASC 842 The objective of the disclosure requirements under ASC 842 is to enable users of an entity’s financial statements to assess the amount, timing and uncertainty of cash flows arising from lease arrangements. In addition to the supplemental qualitative leasing disclosures included above, below are quantitative disclosures that are intended to meet the stated objective of ASC 842.
Derivative Instruments	Commodity swap contracts The Company utilizes commodity swap contracts to hedge against the unfavorable price fluctuations in market prices of electricity. The Company does not apply hedge accounting to these contracts. As such, unrealized and realized gain (loss) is recognized as a component of Renewable Power revenues in the condensed consolidated statement of operations and Derivative financial asset — current and non-current in the condensed consolidated balance sheets. These are considered to be Level 2 instruments in the fair value hierarchy. By using commodity swaps, the Company exposes itself to credit risk and market risk. Credit risk is the failure of the counter party to perform under the terms of the swap contract. When the fair value of the swap contract is positive, the counter party owes the Company creating a credit risk. The Company manages the credit risk by entering into contracts with financially sound counter parties. To mitigate this risk, management monitors counterparty credit exposure on an annual basis, and the necessary credit adjustments have been reflected in the fair value of financial derivative instruments. When the fair value of the swap contract is negative, the Company owes the counterparty creating a market risk that the market price is higher than the contract price resulting in the Company not participating in the opportunity to earn higher revenues.
Fair value measurements	Fair value measurements The fair value of financial instruments, including long-term debt and derivative instruments is defined as the amount at which the instruments could be exchanged in a current transaction between willing parties. The carrying amount of cash and cash equivalents, accounts receivable, net, and accounts payable and accrued expenses approximates fair value due to their short-term maturities. Fair Value Measurement , regarding fair value measurements which establishes a three-tier fair value hierarchy and prioritizes the inputs used in valuation techniques that measure fair value. These tiers include: Level 1 — defined as observable inputs such as quoted prices for identical instruments in active markets; Level 2 — defined as quoted prices for similar instruments in active market, quoted prices for identical or similar instruments in markets that are not active, or model-derived valuations for which all significant inputs are observable market data; Level 3 — defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company's assessment of the significance of an input to the fair value measurement requires judgment and may affect the valuation of fair value assets and liabilities and their placement within the fair value hierarchy levels. The Company values its energy commodity swap contracts based on the applicable geographical market energy forward curve. The forward curves are derived based on the quotes provided by New York Mercantile Exchange, Amerex Energy Services and Tradition Energy. The Company does not consider that the pricing index used involves significant judgement on the part of management. Therefore, the Company classifies these commodity swap contracts within Level 2 of the valuation hierarchy based on the observable market rates used to determine fair value.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2024
Accounting Policies [Abstract]
Schedule of Cash, Cash Equivalents and Restricted Cash	Cash, cash equivalents, and restricted cash consisted of the following as of March 31, 2024 and December 31, 2023: March 31, December 31, Current assets: Cash and cash equivalents $ 28,207 $ 38,348 Restricted cash - current (1) 1,012 4,395 Long-term assets: Restricted cash held as collateral (2) 3,477 4,499 Total cash, cash equivalents, and restricted cash $ 32,696 $ 47,242 (1) Restricted cash - current as of March 31, 2024 consists of $1,012 related to debt reserve on Sunoma Loan. Restricted cash - current as of December 31, 2023 consists of $3,361 related to debt reserve on Sunoma Loan and $1,034 relates to deposit on our interconnections payments. (2)
Schedule of Cash, Cash Equivalents and Restricted Cash	Cash, cash equivalents, and restricted cash consisted of the following as of March 31, 2024 and December 31, 2023: March 31, December 31, Current assets: Cash and cash equivalents $ 28,207 $ 38,348 Restricted cash - current (1) 1,012 4,395 Long-term assets: Restricted cash held as collateral (2) 3,477 4,499 Total cash, cash equivalents, and restricted cash $ 32,696 $ 47,242 (1) Restricted cash - current as of March 31, 2024 consists of $1,012 related to debt reserve on Sunoma Loan. Restricted cash - current as of December 31, 2023 consists of $3,361 related to debt reserve on Sunoma Loan and $1,034 relates to deposit on our interconnections payments. (2)
Project Development and Startup Costs	The following table provides information on the types of expenses classified under this expense category: Three Months Ended March 31, 2024 2023 Site lease expenses $ 275 $ 254 Legal and professional fees 288 275 Royalties — 500 Virtual pipeline costs 119 700 Management services (1) 30 126 Other 73 28 Total Project development and startup costs $ 785 1,883 (1) Relates to charges billed to the individual projects by Fortistar. See Note. 10 Related parties for additional information.
Changes in the Asset Retirement Obligation	The changes in the asset retirement obligations were as follows as of March 31, 2024: March 31, Balance, December 31, 2023 - Current and non-current $ 6,728 Payment of asset retirement obligations during the year — Accretion expense 152 Total asset retirement obligation 6,880 Less: current portion (1,812) Total asset retirement obligation, net of current portion $ 5,068
Disaggregation of Revenue By Product Line	The following table shows the disaggregation of revenue according to product line: Three Months Ended 2024 2023 Renewable Power sales $ 5,819 $ 9,604 Third party construction 10,790 7,154 Service 5,335 4,904 Brown gas sales 5,602 7,530 Environmental credits (1) 35,677 12,677 Parts sales 397 187 Other 341 — Total revenue from contracts with customers 63,961 42,056 Lease revenue (2) 991 901 Total revenue $ 64,952 $ 42,957 (1) Includes revenues of $3,617 and $5,168 for the three months ended March 31, 2024 and 2023, from customers domiciled outside of United States. (2)
Schedule of Other Income (Expense)	The following table shows the items consisting of items recorded as Other income (expense): Three Months Ended March 31, 2024 2023 Gain on transfer of non-financial asset in exchange for services received (1) $ 665 $ 270 Loss on warrant exchange — (338) Other income (expense) $ 665 $ (68) (1) Represents the fair value of RINs transferred as consideration for services received.
Receivables, Contract Assets and Contract Liabilities From Contracts With Customers	The following table provides information about receivables, contract assets, and contract liabilities from contracts with customers: March 31, December 31, Accounts receivable, net $ 22,805 $ 27,623 Contract assets: Cost and estimated earnings in excess of billings $ 6,818 $ 4,630 Accounts receivable retainage, net 2,179 2,160 Contract assets total $ 8,997 $ 6,790 Contract liabilities: Billings in excess of costs and estimated earnings $ 7,785 $ 6,314 Contract liabilities total $ 7,785 $ 6,314

Investments in Other Entities (

Investments in Other Entities (Tables)	3 Months Ended
	Mar. 31, 2024
Equity Method Investments and Joint Ventures [Abstract]
Summary of Equity Method Investments	The following table shows the movement of Investment in Other Entities: Pine Bend Noble Road GREP SJI Paragon Total Percentage of ownership 50 % 50 % 20 % 50 % 50 % Balance at December 31, 2023 $ 21,062 $ 22,174 $ 2,015 $ 1,567 $ 160,281 $ 207,099 Net income from equity method investment 1,042 1,469 (71) (59) 3,255 5,636 Contribution by the Company — — — 1,500 — 1,500 Distributions from return on investment in equity method investment (1) (996) (1,400) — — (2,019) (4,415) Distributions from return of investment in equity method investment (2) (104) — — — (2,622) (2,726) Accumulated other comprehensive income — — — — 350 350 Amortization of basis difference (3) (46) (147) — — (1,237) (1,430) Balance at March 31, 2024 $ 20,958 $ 22,096 $ 1,944 $ 3,008 $ 158,008 $ 206,014 (1) Recorded as part of cash flows from operating activities for the three months ended March 31, 2024. (2) Recorded as part of cash flows from investing activities for the three months ended March 31, 2024. (3) Reflected in Income from equity method investments in the condensed consolidated statement of operations for the three months ended March 31, 2024. The following table summarizes the activity from our equity method investments as well as our share of net income from equity method investments: Three Months Ended March 31, 2024 2023 Revenue $ 25,407 $ 7,539 Gross profit 11,094 1,651 Net income (loss) 10,704 (213) Net income from equity method investments (1) $ 4,206 $ 705 (1)

Property, Plant, and Equipmen_2

Property, Plant, and Equipment, Net (Tables)	3 Months Ended
	Mar. 31, 2024
Property, Plant and Equipment [Abstract]
Summary of Property, Plant, and Equipment, Net	Property, plant, and equipment, net, consisted of the following as of March 31, 2024 and December 31, 2023: March 31, December 31, Plant and equipment $ 198,174 $ 205,188 CNG/RNG fueling stations 56,529 51,749 Construction in progress (1) 193,006 175,060 Buildings 2,585 2,585 Land 1,303 1,303 Service equipment 2,499 2,481 Leasehold improvements 815 815 Vehicles 489 489 Office furniture and equipment 307 307 Computer software 277 277 Land lease - finance lease 6,283 6,469 Vehicles - finance leases 2,460 2,580 Other 591 591 465,318 449,894 Less: accumulated depreciation (105,949) (110,401) Property, plant, and equipment, net $ 359,369 $ 339,493 (1) Includes capitalized interest of $1,444 and $5,475, respectively, for the three months ended March 31, 2024 and year ended December 31, 2023.

Intangible Assets, Net (Tables)

Intangible Assets, Net (Tables)	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Intangible Assets with Definite Lives	Intangible assets, net, consisted of the following at March 31, 2024 and December 31, 2023: March 31, 2024 Cost Accumulated Intangible Weighted Power purchase agreements $ 8,999 $ (7,469) $ 1,530 18.1 Transmission/distribution interconnection 1,600 (1,600) — 15.1 Intellectual property 43 (36) 7 5.0 Total intangible assets $ 10,642 $ (9,105) $ 1,537 December 31, 2023 Cost Accumulated Intangible Weighted Power purchase agreements $ 8,999 $ (7,926) $ 1,073 18.1 Transmission/distribution interconnection 1,600 (1,076) 524 15.1 Intellectual property 43 (36) 7 5.0 Total intangible assets $ 10,642 $ (9,038) $ 1,604
Schedule of Estimated Future Amortization Expense For Definite Lived Intangible Assets	At March 31, 2024, estimated future amortization expense for intangible assets is as follows: Nine months ending December 31, 2024 $ 205 Fiscal year: 2025 267 2026 231 2027 171 2028 171 Thereafter 492 $ 1,537

Goodwill (Tables)

Goodwill (Tables)	3 Months Ended
	Mar. 31, 2024
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill	The following table summarizes the changes in goodwill, if any, by reporting segment from the beginning of the period to the end of the period: RNG Fuel Fuel Station Services Total Balance December 31, 2023 $ 51,155 $ 3,453 $ 54,608 Balance March 31, 2024 $ 51,155 $ 3,453 $ 54,608

Borrowings (Tables)

Borrowings (Tables)	3 Months Ended
	Mar. 31, 2024
Debt Disclosure [Abstract]
Schedule of Borrowings	The following table summarizes the borrowings under the various debt facilities as of March 31, 2024 and December 31, 2023: March 31, 2024 December 31, 2023 OPAL Term Loan 186,618 186,618 Less: unamortized debt issuance costs (9,591) (10,086) Less: current portion (1,866) — OPAL Term Loan, net of debt issuance costs 175,161 176,532 Sunoma Loan 22,074 22,453 Less: unamortized debt issuance costs (813) (835) Less: current portion (1,652) (1,608) Sunoma Loan, net of debt issuance costs 19,609 20,010 Non-current borrowings total $ 194,770 $ 196,542
Schedule of Principal Maturities of Debt	As of March 31, 2024, principal maturities of debt are expected as follows, excluding any subsequent refinancing transactions and any undrawn debt facilities as of the date of the condensed consolidated balance sheets: OPAL Term Loan Sunoma Loan Total Nine months ending December 31, 2024 $ — $ 1,229 $ 1,229 Fiscal year: 2025 7,354 1,756 9,110 2026 7,064 1,898 8,962 2027 6,786 2,051 8,837 2028 165,414 2,213 167,627 Thereafter — $ 12,927 $ 12,927 $ 186,618 $ 22,074 $ 208,692
Schedule of Interest Expense on Borrowings	The following table summarizes the Company's total interest expense for the three months ended March 31, 2024 and 2023: Three Months Ended 2024 2023 Senior Secured Credit Facility $ 2 $ 281 Convertible Note Payable mark-to-market — 563 Sunoma Loan 461 445 OPAL Term Loan (1) 2,769 19 Equipment loan (2) 5 — Commitment fees and other finance fees 688 128 Amortization of deferred financing cost 555 450 Interest expense on finance leases 147 16 Interest income (666) (1,261) Total interest expense $ 3,961 $ 641 (1) Excludes $1,444 and $1,808 of interest capitalized and recorded as part of Property, Plant and Equipment for the three months ended March 31, 2024 and 2023, respectively. (2) Sunoma equipment loan recorded as part of Other current liabilities and Other long-term liabilities as of March 31, 2024.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2024
Leases [Abstract]
Right-Of-Use Assets And Lease Liabilities	Right-of-use assets and Lease liabilities as of March 31, 2024 and December 31, 2023 are as follows: Description Location in Balance Sheet March 31, 2024 December 31, 2023 Assets: Operating leases (1) : Site leases Right-of-use assets $ 11,278 $ 11,330 Office lease Right-of-use assets 859 971 12,137 12,301 Finance leases (1) : Vehicle leases Property, plant and equipment, net 2,460 2,580 Site leases Property, plant and equipment, net 6,283 6,468 8,743 9,048 Total right-of-use assets $ 20,880 $ 21,349 Liabilities (1) : Sites leases - operating Lease liabilities - current portion 138 $ 130 Office lease - operating Lease liabilities - current portion 518 508 Vehicle leases - finance Accrued expenses and other current liabilities 862 827 Site leases - finance Accrued expenses and other current liabilities 583 571 2,101 2,036 Sites leases - operating Operating lease liabilities - non-current portion 11,178 11,222 Office lease - operating Operating lease liabilities - non-current portion 468 602 Vehicle leases - finance Other long-term liabilities 1,661 1,801 Site leases - finance Other long-term liabilities $ 5,679 $ 5,587 18,986 19,212 Total lease liabilities $ 21,087 $ 21,248 (1) The Operating and Finance lease right-of-use asset and Operating and Finance lease liabilities represent the present value of lease payments for the remaining term of the lease. The discount rate used ranged from 3.59% to 8.44%. The table below presents components of the Company's lease expense for the three months ended March 31, 2024 and 2023: Description Location in Statement of Operations Three Months Ended March 31, 2024 2023 Operating lease expense for site leases Cost of sales - RNG Fuel $ 283 $ 263 Operating lease expense for office lease Selling, general, administrative expenses 121 121 Amortization of right-of-use assets - finance leases Depreciation, amortization and accretion expense 234 140 Interest expense on lease liabilities - finance leases Interest and financing expense, net 147 16 $ 785 $ 540 The Company does not have material short term lease expense for the three months ended March 31, 2024 and 2023. The Company did not enter into any operating leases greater than 12 months for the three months ended March 31, 2024. Weighted average remaining lease term (years) March 31, 2024 Operating leases 19.2 Financing leases 6.8 Weighted average discount rate Operating leases 7.85 % Financing leases 6.60 %
Future Minimum Lease Payments - Operating Leases	The table below provides the total amount of lease payments on an undiscounted basis on our lease contracts as of March 31, 2024: Site leases Office leases Vehicle leases Site lease - Finance Total Weighted average discount rate 7.6 % 3.6 % 6.3 % 6.5 % 2024 $ 797 $ 406 $ 804 $ 963 $ 2,970 2025 1,129 562 966 963 3,620 2026 1,129 47 810 963 2,949 2027 1,129 — 429 963 2,521 2028 and beyond 20,310 — 5 4,250 24,565 24,494 1,015 3,014 8,102 36,625 Present value of lease liability 11,316 986 2,523 6,262 21,087 Lease liabilities - current portion 138 518 862 583 2,101 Lease liabilities - non-current portion 11,178 468 1,661 5,679 18,986 Total lease liabilities $ 11,316 $ 986 $ 2,523 $ 6,262 $ 21,087 Discount based on incremental borrowing rate $ 13,178 $ 29 $ 491 $ 1,840 $ 15,538
Future Minimum Lease Payments - Finance Leases	The table below provides the total amount of lease payments on an undiscounted basis on our lease contracts as of March 31, 2024: Site leases Office leases Vehicle leases Site lease - Finance Total Weighted average discount rate 7.6 % 3.6 % 6.3 % 6.5 % 2024 $ 797 $ 406 $ 804 $ 963 $ 2,970 2025 1,129 562 966 963 3,620 2026 1,129 47 810 963 2,949 2027 1,129 — 429 963 2,521 2028 and beyond 20,310 — 5 4,250 24,565 24,494 1,015 3,014 8,102 36,625 Present value of lease liability 11,316 986 2,523 6,262 21,087 Lease liabilities - current portion 138 518 862 583 2,101 Lease liabilities - non-current portion 11,178 468 1,661 5,679 18,986 Total lease liabilities $ 11,316 $ 986 $ 2,523 $ 6,262 $ 21,087 Discount based on incremental borrowing rate $ 13,178 $ 29 $ 491 $ 1,840 $ 15,538

Derivative Financial Instrume_2

Derivative Financial Instruments and Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2024
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Effect of Derivative Instruments on Statement of Operations	The effect of interest rate swaps on the condensed consolidated statement of operations were as follows: Three Months Ended Location of (Loss) Gain Recognized in Operations from Derivatives 2024 2023 Swaption (1) — (66) $ — $ (66) Change in fair value of derivative instruments, net (1) The Swaption was terminated on May 30, 2023. The following table summarizes the effect of commodity swaps on the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023: Derivatives not designated as hedging instruments Location of (loss) gain recognized Three Months Ended March 31, 2024 2023 Commodity swaps - realized gain Revenues - Renewable Power $ 178 $ 371 Commodity swaps - unrealized (loss) gain Revenues - Renewable Power (96) 922 Total realized and unrealized gain Revenues - Renewable Power $ 82 $ 1,293
Summary of Commodity Swaps And Other Derivatives	The following table summarizes the commodity swaps in place as of March 31, 2024 and December 31, 2023. There were no new commodity swap contracts entered during the three months ended March 31, 2024. Trade Date Period From Period To Notional Quantity per Year (“MWh”) Average Contract Price (per MWh) October 17, 2022 January 1, 2023 December 31, 2024 70,176 $ 68.50 November 17, 2022 January 1, 2023 December 31, 2024 35,088 $ 81.50 The following table summarizes the effect of change in fair value of other derivative liabilities on the condensed consolidated statements of operations for the three months ended March 31, 2024 and 2023: Derivative liability Three Months Ended March 31, Location of (Loss) Gain Recognized in Operations from Derivatives 2024 2023 Put option to Meteora $ — $ (311) Sponsor Earnout Awards 403 310 OPAL Earnout Awards — 4,000 $ 403 $ 3,999 Change in fair value of derivative instruments, net
Derivatives Fair Values on Balance Sheet	The following table summarizes the derivative assets and liabilities related to commodity swaps as of March 31, 2024 and December 31, 2023: Fair Value Location of Fair value recognized in Balance Sheet March 31, 2024 December 31, 2023 Derivatives designated as economic hedges Current portion of unrealized gain on commodity swaps $ 537 $ 633 Derivative financial asset, current portion
Assets and Liabilities Measured at Fair Value on Recurring Basis	The Company's assets and liabilities that are measured at fair value on a recurring basis include the following as of March 31, 2024 and December 31, 2023, set forth by level, within the fair value hierarchy: Fair value as of March 31, 2024 Level 1 Level 2 Level 3 Total Liabilities: Asset retirement obligation $ — $ — $ 6,880 $ 6,880 Earnout liabilities — — 1,497 1,497 Assets: Cash and cash equivalents and restricted cash - current and non-current (1) 32,696 — — 32,696 Short term investments 5,975 — — 5,975 Commodity swap contracts — 537 — 537 Fair value as of December 31, 2023 Level 1 Level 2 Level 3 Total Liabilities: Asset retirement obligation $ — $ — $ 6,728 $ 6,728 Earnout liabilities — — 1,900 1,900 Assets: Cash and cash equivalents and restricted cash - current and non-current (1) 47,242 — — 47,242 Short term investments 9,875 — — 9,875 Commodity swap contracts — 633 — 633 (1) Includes balances in money market accounts of $18,854 and $31,965, respectively as of March 31, 2024 and December 31, 2023.

Related Parties (Tables)

Related Parties (Tables)	3 Months Ended
	Mar. 31, 2024
Related Party Transactions [Abstract]
Fees Upon Entering Into Management Services Agreement with Related Party and Various Balances for Related Parties	The following table summarizes the various fees recorded under the agreements described above which are included in "Selling, general, and administrative" expenses: Three Months Ended March 31, 2024 2023 Staffing and management services $ 462 $ 575 Rent - fixed compensation 171 165 IT services 704 726 Total $ 1,337 $ 1,466 The following table presents the various balances for related parties included in our consolidated balance sheets as of March 31, 2024 and December 31, 2023: Location in Balance Sheet March 31, 2024 December 31, 2023 Assets: Trade AR - NextEra Accounts receivable, related party $ 14,912 $ 18,696 Liabilities: Payables to equity method investment entities Accounts payable, related party 6,737 5,692 NextEra Accounts payable, related party 500 501 Staffing and management services - Fortistar Accounts payable, related party 682 622 IT services - Costar Accounts payable, related party 247 209 Total liabilities - related party $ 8,166 $ 7,024

Reportable Segments and Geogr_2

Reportable Segments and Geographic Information (Tables)	3 Months Ended
	Mar. 31, 2024
Segment Reporting [Abstract]
Schedule of Total Revenues by Segment	The Company has determined that each of the four operating segments meets the characteristics of a reportable segment under U.S. GAAP. The Company's activities and assets that are not associated with the four reportable segments are summarized in the "Other" category below. These include corporate investment income, interest income and interest expense, income tax expense, and other non-allocated costs. Three Months Ended 2024 2023 Revenues: Renewable Power $ 10,083 $ 15,363 RNG Fuel (1) 42,792 14,288 Fuel Station Services (2) 41,650 24,575 Other (3) 342 17 Intersegment (4,508) (3,747) Equity Method Investment(s) (25,407) (7,539) $ 64,952 $ 42,957 ____________ (1) Includes revenues from our equity method investments. (2) Includes intersegment revenues eliminated in the condensed consolidated financial statements. (3) Other includes management fee revenues earned from operations and management of unconsolidated entities and Fortistar Contracting LLC.
Schedule of Interest Expense on Borrowings, Depreciation, Amortization and Accretion and Cash Paid for Purchases, Plant and Equipment	Three Months Ended 2024 2023 Interest and Financing Expense, Net: Renewable Power $ 60 $ (264) RNG Fuel (4,291) (655) Fuel Station Services 23 10 Corporate 131 202 Equity Method Investment(s) $ 116 $ 66 $ (3,961) $ (641) Three Months Ended 2024 2023 Depreciation, Amortization, and Accretion: Renewable Power $ 1,000 $ 1,452 RNG Fuel 2,346 2,024 Fuel Station Services 1,319 790 Other (1) — 16 Equity Method Investment(s) (954) (715) $ 3,711 $ 3,567 (1) Other includes amortization of intangible assets and depreciation expense not allocated to any segment. Three Months Ended 2024 2023 Cash paid for Purchases of Property, Plant, and Equipment: Fuel Station Services $ 3,795 $ 5,665 RNG Fuel 22,957 33,115 $ 26,752 $ 38,780
Schedule of Net (Loss) Income	Three Months Ended 2024 2023 Net income (loss) Renewable Power $ (73) $ 4,542 RNG Fuel 2,925 (4,268) Fuel Station Services 5,722 41 Corporate (12,103) (8,366) Equity Method Investment(s) 4,206 705 $ 677 $ (7,346)
Total Assets	Three Months Ended 2024 2023 Total Assets: Renewable Power $ 36,266 $ 46,199 RNG Fuel 332,204 347,591 Fuel Station Services 150,739 110,113 Corporate and other 25,276 52,229 Equity Method Investment(s) 206,014 50,570 $ 750,499 $ 606,702

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	3 Months Ended
	Mar. 31, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Variable Interest Entities	The amount of assets that can only be used to settle obligations of the VIEs are parenthesized in the condensed consolidated balance sheets and are included in the asset totals listed in the table below. As of As of Assets Current assets: Cash and cash equivalents $ 1,160 $ 166 Accounts receivable, net 334 33 Restricted cash - current 1,012 4,395 Parts inventory 29 29 Prepaid expenses and other current assets 113 107 Total current assets 2,648 4,730 Property, plant and equipment, net 26,254 26,626 Restricted cash, non-current 1,957 1,850 Total assets $ 30,859 $ 33,206 Liabilities and equity Current liabilities: Accounts payable $ 11 $ 744 Accounts payable, related party 802 1,046 Accrued expenses 861 647 Other current liabilities 94 92 Sunoma Loan- current portion 1,652 1,608 Total current liabilities 3,420 4,137 Sunoma loan, net of debt issuance costs 19,609 20,010 Other long-term liabilities 1,297 211 Total liabilities 24,326 24,358 Equity Stockholders' equity 5,809 7,893 Non-redeemable non-controlling interests 724 955 Total equity 6,533 8,848 Total Liabilities and Equity $ 30,859 $ 33,206

Redeemable non-controlling in_2

Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' (Deficit) Equity (Tables)	3 Months Ended
	Mar. 31, 2024
Equity [Abstract]
Changes in Redeemable Preferred Units	The following table summarizes the changes in the redeemable preferred non-controlling interests which represent Series A and Series A-1 preferred units outstanding at OPAL Fuels level from December 31, 2023 to March 31, 2024: Series A-1 preferred units Series A preferred units Units Amount Units Amount Total Balance, December 31, 2023 300,000 $ 30,604 1,000,000 $ 102,013 $ 132,617 Preferred dividends attributable to OPAL Fuels — 506 — 1,686 2,192 Preferred dividends attributable to Class A common stockholders — 98 — 328 426 Payment of Preferred dividends — (1,208) — (4,027) (5,235) Balance, March 31, 2024 300,000 $ 30,000 1,000,000 $ 100,000 $ 130,000

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	3 Months Ended
	Mar. 31, 2024
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Loss Per Unit	The following table summarizes the calculation of basic and diluted net loss per share: Three Months Ended 2024 2023 Net loss attributable to Class A common stockholders $ (316) $ (1,579) Weighted average number of shares of Class A common stock - basic 27,368,204 27,383,562 Dilutive effect of stock options, restricted stock units, performance units, Convertible note payable, earnout shares, Redeemable preferred non-controlling interests, Redeemable non-controlling interests — — Weighted average number of shares of Class A common stock - diluted 27,368,204 27,383,562 Net loss per share of Class A common stock Basic $ (0.01) $ (0.06) Diluted $ (0.01) $ (0.06)

Stock-based compensation (Table

Stock-based compensation (Tables)	3 Months Ended
	Mar. 31, 2024
Share-Based Payment Arrangement [Abstract]
Summary of Equity Awards Under 2022 Plan	A summary of the equity awards under the 2022 Plan for the three months ended March 31, 2024 is as follows: Restricted stock units Weighted average fair value per restricted unit on grant date Exercise price per Stock Option Aggregate fair value Vesting terms Restricted Stock Units: Unvested restricted stock units outstanding as of December 31, 2023 949,936 $ 6.98 $ — $ 6,627 Equal installments vesting over one Granted during the quarter ending March 31, 2024 1,300,557 4.98 — 6,479 Equal installments vesting over one Vested during 2024 (307,137) 6.97 — (2,141) Withheld for settlement of taxes (112,402) 6.97 — (783) Forfeitures during 2024 (2,870) 6.97 — (20) Unvested restricted stock units outstanding at March 31, 2024 1,828,084 $ 5.56 $ — $ 10,162 Stock Options: (1) Outstanding awards as of December 31, 2023 175,890 $ 5.26 $ 6.97 $ 925 Three equal installments vesting over three years Granted in March 2024 360,298 3.40 5.02 1,225 Three equal installments vesting over three years Outstanding Stock Options at March 31, 2024 536,188 $ 4.01 $ 5.66 2,150 Options vested and exercisable as of March 31, 2024 62,327 5.26 6.97 328 Performance Stock Units: Unvested awards as of December 31, 2023 239,680 6.97 — $ 1,671 100% vesting on March 31, 2026 Granted in March 2024 456,308 4.97 — 2,267 100% vesting on March 31, 2027 Forfeitures during 2024 (1,865) 6.97 — (13) Performance Stock Units outstanding as of March 31, 2024 694,123 $ 5.65 $ — $ 3,925 Total unvested awards outstanding as of March 31, 2024 3,120,722 $ 5.31 16,565 (1)
Stock-based Compensation Expense	The stock-based compensation expense for the above stock awards under the 2022 Plan as well as Parent Equity Awards is included in the selling, general and administrative expenses: Three Months Ended March 31, 2024 2023 2022 Plan $ 853 $ 811 Parent equity awards 160 160 $ 1,013 $ 971

Organization and Description _2

Organization and Description of Business (Details)	3 Months Ended
	Mar. 31, 2024 segment
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of operating segments	4

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 28,207	$ 38,348
Restricted cash - current	1,012	4,395
Long-term assets:
Restricted cash held as collateral	3,477	4,499
Total cash, cash equivalents, and restricted cash	32,696	47,242	$ 39,822	$ 77,221
Deposit on interconnection payments		1,034
Sunoma Loan
Long-term assets:
Debt reserve	$ 1,012	$ 3,361

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Short-Term Investments, Earnout Awards, and Redeemable Noncontrolling Interests Narrative (Details) - USD ($) $ in Thousands		3 Months Ended		20 Months Ended
	Jul. 21, 2022	Mar. 31, 2024	Mar. 31, 2023	Mar. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Short term investments		$ 5,975		$ 5,975	$ 9,875
Contingent consideration (in shares)	10,000,000
Gain on Earnout Awards		403	$ 4,310
Earn out liabilities		1,497		1,497	$ 1,900
Class B Ordinary Share | Opal Fuels
Derivative [Line Items]
Stock issued (in shares)	144,399,037
Redeemable non-controlling interests
Derivative [Line Items]
Change in redemption value of Redeemable non-controlling interests		$ (97,044)	$ 7,720	$ 705,190
Sponsor Letter Agreement
Derivative [Line Items]
Percentage of common stock subject to vesting and forfeiture conditions	10%
Common stock subject to vesting and forfeiture conditions, period	60 months

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Project Development and Startup Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounting Policies [Abstract]
Site lease expenses	$ 275	$ 254
Legal and professional fees	288	275
Royalties	0	500
Virtual pipeline costs	119	700
Management services	30	126
Other	73	28
Total Project development and startup costs	$ 785	$ 1,883

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Accounts Receivable, Net and Asset Retirement Obligation Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Allowance for credit losses	$ 82	$ 0
Estimated value of total asset retirement obligation	$ 6,880	$ 6,728

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Changes in the Asset Retirement Obligation (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Asset retirement obligation, beginning balance	$ 6,728
Payment of asset retirement obligations during the year	0
Accretion expense	152	$ 102
Asset retirement obligation, ending balance	6,880
Less: current portion	(1,812)		$ (1,812)
Total asset retirement obligation, net of current portion	$ 5,068		$ 4,916

Summary of Significant Accoun_9

Summary of Significant Accounting Policies - Revenue Recognition, Contract Balances, Fuel Station Construction Backlog and Major Maintenance Narrative (Details) $ in Thousands	3 Months Ended			6 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) producer facility	Sep. 30, 2023 facility	Mar. 31, 2023 USD ($)	Dec. 31, 2022 subsidiary	Dec. 31, 2023 USD ($)	Nov. 29, 2021
Revenue from External Customer [Line Items]
Number of natural gas producers | producer	2
Total revenues	$ 64,952		$ 42,957
Revenue recognized included in contract liabilities	2,746				$ 8,013
Backlog	43,731
Major maintenance expense	2,909		$ 2,076
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-04-01
Revenue from External Customer [Line Items]
Backlog	$ 32,917
Backlog recognition period (in months)	12 months
Transferred over Time
Revenue from External Customer [Line Items]
Percentage of revenue recognized over time	16.60%		16.60%
RNG Fuel
Revenue from External Customer [Line Items]
Total revenues	$ 17,727		$ 6,749
Fuel Station Services
Revenue from External Customer [Line Items]
Total revenues	37,142		20,828
Environmental credits held-for-sale	3,156		1,218
Renewable Power
Revenue from External Customer [Line Items]
Total revenues	10,083		15,380
Number of wholly-owned subsidiaries | subsidiary				2
Related Party | RNG Fuel
Revenue from External Customer [Line Items]
Total revenues	15,495		4,715
Related Party | Fuel Station Services
Revenue from External Customer [Line Items]
Total revenues	7,741		1,493
Related Party | Renewable Power
Revenue from External Customer [Line Items]
Total revenues	$ 1,526		1,527
RNG Fuel
Revenue from External Customer [Line Items]
Term of agreement (in years)		3 years
Number of facilities | facility	2	3
NextEra | RNG Fuel
Revenue from External Customer [Line Items]
Minimum of environmental attributes to be sold, percentage						90%
OCI Fuels B.V. ("OCI") | Environmental Attributes
Revenue from External Customer [Line Items]
Term of agreement (in years)				3 years
OCI Fuels B.V. ("OCI") | Environmental Attributes | Renewable Power
Revenue from External Customer [Line Items]
Total revenues	$ 3,788		$ 5,445

Summary of Significant Accou_10

Summary of Significant Accounting Policies - Disaggregation of Revenue By Product Line (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) fuel_station facility agreement	Sep. 30, 2023 facility	Mar. 31, 2023 USD ($)
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 63,961		$ 42,056
Lease revenue	991		901
Total revenues	$ 64,952		42,957
Fuel Purchasing Agreements
Disaggregation of Revenue [Line Items]
Number of agreements | agreement	26
Renewable Power sales
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 5,819		9,604
Third party construction
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	10,790		7,154
Service
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,335		4,904
Brown gas sales
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	5,602		7,530
Environmental credits
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	35,677		12,677
Environmental credits | Non-US
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	3,617		5,168
Parts sales
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	397		187
Other
Disaggregation of Revenue [Line Items]
Total revenue from contracts with customers	$ 341		$ 0
RNG Fuel
Disaggregation of Revenue [Line Items]
Number of fuel stations | fuel_station	2
Number of facilities | facility	2	3

Summary of Significant Accou_11

Summary of Significant Accounting Policies - Other Income (Expense) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounting Policies [Abstract]
Gain on transfer of non-financial asset in exchange for services rendered	$ 665	$ 270
Loss on warrant exchange	0	(338)
Other income (expense)	$ 665	$ (68)

Summary of Significant Accou_12

Summary of Significant Accounting Policies - Receivables, Contract Assets and Contract Liabilities From Contracts With Customers (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Accounting Policies [Abstract]
Accounts receivable, net	$ 22,805	$ 27,623
Contract assets:
Cost and estimated earnings in excess of billings	6,818	4,630
Accounts receivable retainage, net	2,179	2,160
Contract assets	8,997	6,790
Contract liabilities:
Billings in excess of costs and estimated earnings	7,785	6,314
Contract liabilities	$ 7,785	$ 6,314

Summary of Significant Accou_13

Summary of Significant Accounting Policies - Significant Customers, Vendors and Concentration of Credit Risk Narrative (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Accounts Payable | Supplier Concentration Risk | One Vendor
Finite-Lived Intangible Assets [Line Items]
Concentration risk percentage			32%
Two Customers | Revenue Benchmark | Customer Concentration Risk
Finite-Lived Intangible Assets [Line Items]
Concentration risk percentage	55%
Two Customers | Accounts Receivable | Customer Concentration Risk
Finite-Lived Intangible Assets [Line Items]
Concentration risk percentage	58%		54%
Three Customers | Revenue Benchmark | Customer Concentration Risk
Finite-Lived Intangible Assets [Line Items]
Concentration risk percentage		44%

Investments in Other Entities -

Investments in Other Entities - Summary of Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Aug. 31, 2021
Increase (Decrease) In Equity Method Investments [Roll Forward]
Beginning balance	$ 207,099
Net income from equity method investment	5,636
Contribution by the Company	1,500
Distributions from return on investment in equity method investment	(4,415)	$ 0
Distributions from return on investment in equity method investment	(2,726)	(1,900)
Accumulated other comprehensive income	350
Amortization of basis difference	(1,430)
Ending balance	$ 206,014	$ 50,570
Pine Bend
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50%
Increase (Decrease) In Equity Method Investments [Roll Forward]
Beginning balance	$ 21,062
Net income from equity method investment	1,042
Contribution by the Company	0
Distributions from return on investment in equity method investment	(996)
Distributions from return on investment in equity method investment	(104)
Accumulated other comprehensive income	0
Amortization of basis difference	(46)
Ending balance	$ 20,958
Noble Road
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50%
Increase (Decrease) In Equity Method Investments [Roll Forward]
Beginning balance	$ 22,174
Net income from equity method investment	1,469
Contribution by the Company	0
Distributions from return on investment in equity method investment	(1,400)
Distributions from return on investment in equity method investment	0
Accumulated other comprehensive income	0
Amortization of basis difference	(147)
Ending balance	$ 22,096
GREP
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20%		20%
Increase (Decrease) In Equity Method Investments [Roll Forward]
Beginning balance	$ 2,015
Net income from equity method investment	(71)
Contribution by the Company	0
Distributions from return on investment in equity method investment	0
Distributions from return on investment in equity method investment	0
Accumulated other comprehensive income	0
Amortization of basis difference	0
Ending balance	$ 1,944
SJI
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50%
Increase (Decrease) In Equity Method Investments [Roll Forward]
Beginning balance	$ 1,567
Net income from equity method investment	(59)
Contribution by the Company	1,500
Distributions from return on investment in equity method investment	0
Distributions from return on investment in equity method investment	0
Accumulated other comprehensive income	0
Amortization of basis difference	0
Ending balance	$ 3,008
Paragon
Schedule of Equity Method Investments [Line Items]
Ownership percentage	50%
Increase (Decrease) In Equity Method Investments [Roll Forward]
Beginning balance	$ 160,281
Net income from equity method investment	3,255
Contribution by the Company	0
Distributions from return on investment in equity method investment	(2,019)
Distributions from return on investment in equity method investment	(2,622)
Accumulated other comprehensive income	350
Amortization of basis difference	(1,237)
Ending balance	$ 158,008

Investments in Other Entities_2

Investments in Other Entities - Summary of Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Schedule of Equity Method Investments [Line Items]
Total revenues	$ 64,952	$ 42,957
Net income (loss)	677	(7,346)
Net income from equity method investment	4,206	705
Equity Method Investment(s)
Schedule of Equity Method Investments [Line Items]
Total revenues	25,407	7,539
Gross profit	11,094	1,651
Net income (loss)	$ 10,704	$ (213)

Property, Plant, and Equipmen_3

Property, Plant, and Equipment, Net - Summary of Property, Plant, and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Finance leases	$ 8,743		$ 9,048
Gross property, plant, equipment and finance leases	465,318		449,894
Less: accumulated depreciation	(105,949)		(110,401)
Property, plant, and equipment, net	359,369		339,493
Interest capitalized	1,444	$ 1,808	5,475
Plant and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	198,174		205,188
CNG/RNG fueling stations
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	56,529		51,749
Construction in progress (1)
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	193,006		175,060
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,585		2,585
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,303		1,303
Finance leases	6,283		6,469
Service equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,499		2,481
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	815		815
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	489		489
Finance leases	2,460		2,580
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	307		307
Computer software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	277		277
Other
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 591		$ 591

Property, Plant, and Equipmen_4

Property, Plant, and Equipment, Net - Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
	Oct. 20, 2023	Mar. 31, 2024	Mar. 31, 2023
Asset Acquisition [Line Items]
Depreciation		$ 3,493	$ 3,305
Pipelines
Asset Acquisition [Line Items]
Capital expenditure		$ 2,500
Pipeline Project | WGL
Asset Acquisition [Line Items]
Purchase price, contingent consideration	$ 25,000

Intangible Assets, Net - Schedu

Intangible Assets, Net - Schedule of Intangible Assets with Definite Lives (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Finite-Lived Intangible Assets [Line Items]
Cost	$ 10,642	$ 10,642
Accumulated Amortization	(9,105)	(9,038)
Intangible Assets, Net	1,537	1,604
Power purchase agreements
Finite-Lived Intangible Assets [Line Items]
Cost	8,999	8,999
Accumulated Amortization	(7,469)	(7,926)
Intangible Assets, Net	$ 1,530	$ 1,073
Weighted Average Amortization Period (Years)	18 years 1 month 6 days	18 years 1 month 6 days
Transmission/distribution interconnection
Finite-Lived Intangible Assets [Line Items]
Cost	$ 1,600	$ 1,600
Accumulated Amortization	(1,600)	(1,076)
Intangible Assets, Net	$ 0	$ 524
Weighted Average Amortization Period (Years)	15 years 1 month 6 days	15 years 1 month 6 days
Intellectual property
Finite-Lived Intangible Assets [Line Items]
Cost	$ 43	$ 43
Accumulated Amortization	(36)	(36)
Intangible Assets, Net	$ 7	$ 7
Weighted Average Amortization Period (Years)	5 years	5 years

Intangible Assets, Net - Narrat

Intangible Assets, Net - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 67	$ 160

Intangible Assets, Net - Sche_2

Intangible Assets, Net - Schedule of Estimated Future Amortization Expense For Definite Lived Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Nine months ending December 31, 2024	$ 205
2025	267
2026	231
2027	171
2028	171
Thereafter	492
Intangible Assets, Net	$ 1,537	$ 1,604

Goodwill (Details)

Goodwill (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 54,608
Goodwill, ending balance	54,608
RNG Fuel
Goodwill [Roll Forward]
Goodwill, beginning balance	51,155
Goodwill, ending balance	51,155
Fuel Station Services
Goodwill [Roll Forward]
Goodwill, beginning balance	3,453
Goodwill, ending balance	$ 3,453

Borrowings - Schedule of Borrow

Borrowings - Schedule of Borrowings (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Non-current borrowings	$ 194,770	$ 196,542
Sunoma Loan
Debt Instrument [Line Items]
Long-term debt, gross	22,074	22,453
Less: unamortized debt issuance costs	(813)	(835)
Less: current portion	(1,652)	(1,608)
Non-current borrowings	19,609	20,010
OPAL Term Loan | OPAL Term Loan
Debt Instrument [Line Items]
Long-term debt, gross	186,618	186,618
Less: unamortized debt issuance costs	(9,591)	(10,086)
Less: current portion	(1,866)	0
Non-current borrowings	$ 175,161	$ 176,532

Borrowings - Schedule of Princi

Borrowings - Schedule of Principal Maturities of Debt (Details) $ in Thousands	Mar. 31, 2024 USD ($)
Debt Instrument [Line Items]
Nine months ending December 31, 2024	$ 1,229
2025	9,110
2026	8,962
2027	8,837
2028	167,627
Thereafter	12,927
Total	208,692
OPAL Term Loan | OPAL Term Loan
Debt Instrument [Line Items]
Nine months ending December 31, 2024	0
2025	7,354
2026	7,064
2027	6,786
2028	165,414
Thereafter	0
Total	186,618
Sunoma Loan
Debt Instrument [Line Items]
Nine months ending December 31, 2024	1,229
2025	1,756
2026	1,898
2027	2,051
2028	2,213
Thereafter	12,927
Total	$ 22,074

Borrowings - Opal Term Loan Nar

Borrowings - Opal Term Loan Narrative (Details) - USD ($) $ in Thousands		3 Months Ended
	Sep. 01, 2023	Mar. 31, 2024	Dec. 31, 2023	Oct. 22, 2021
OPAL Term Loan | Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount				$ 125,000
Debt outstanding		$ 186,618	$ 186,618
Credit Agreement | Line of Credit | Secured Debt
Debt Instrument [Line Items]
Aggregate principal amount	$ 450,000
Term of loan (in years)	18 months
Amortization rate	1%
Minimum required debt service coverage ratio	120%
Minimum debt to cash flow ratio	4.5
Minimum debt to cash flow ratio after delayed draw availability period	4
Credit Agreement | Line of Credit | Secured Debt | Minimum
Debt Instrument [Line Items]
Cash sweep	25%
Credit Agreement | Line of Credit | Secured Debt | Maximum
Debt Instrument [Line Items]
Cash sweep	100%
Credit Agreement | Line of Credit | Secured Debt | Variable Rate, Fixed Margin, Period One | Term Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on permanent loan	3.50%
Credit Agreement | Line of Credit | Secured Debt | Variable Rate, Fixed Margin, Period Two | Term Secured Overnight Financing Rate (SOFR)
Debt Instrument [Line Items]
Basis spread on permanent loan	0.25%
Credit Agreement | Line of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Revolving credit arrangement borrowing capacity	$ 50,000
Proceeds from issuance		$ 13,604
Credit Agreement | Letter of Credit | Revolving Credit Facility
Debt Instrument [Line Items]
Financing fees paid	$ 9,976

Borrowings - Sunoma Loan Narrat

Borrowings - Sunoma Loan Narrative (Details) - USD ($) $ in Thousands	Jul. 19, 2022	Aug. 27, 2020	Mar. 31, 2024	Dec. 31, 2023
Sunoma Loan
Debt Instrument [Line Items]
Aggregate principal amount		$ 20,000
Maximum debt to worth ratio		500%
Minimum current ratio		100%
Minimum required debt service coverage ratio		125%
Debt outstanding			$ 22,074	$ 22,453
Sunoma Loan | Minimum
Debt Instrument [Line Items]
Effective interest rate		7.75%
Sunoma Loan | Prime Rate
Debt Instrument [Line Items]
Basis spread on permanent loan		3.50%
Sunoma Loan | Sunoma
Debt Instrument [Line Items]
Financing fees paid		$ 635
Permanent Loan
Debt Instrument [Line Items]
Aggregate principal amount	$ 23,000
Interest rate on loan	7.68%
Payment of quarterly amortization	$ 380
Debt outstanding			$ 22,074	$ 22,453

Borrowings - Convertible Note P

Borrowings - Convertible Note Payable, Municipality Loan and Senior Secured Credit Facility Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2023	May 01, 2021	Sep. 21, 2015
Convertible Note Payable
Debt Instrument [Line Items]
Aggregate principal amount		$ 50,000
Interest rate on loan	8%	8%
Senior Secured Credit Facility
Debt Instrument [Line Items]
Aggregate principal amount			$ 150,000
Senior Secured Credit Facility | Senior Secured Credit Facility - Debt Reserve And Liquidity Facility
Debt Instrument [Line Items]
Aggregate principal amount			6,000
Senior Secured Credit Facility | Secured Debt | Senior Secured Credit Facility - Term Loan
Debt Instrument [Line Items]
Aggregate principal amount			125,000
Senior Secured Credit Facility | Letter of Credit | Senior Secured Credit Facility, working capital facility
Debt Instrument [Line Items]
Revolving credit arrangement borrowing capacity			$ 19,000

Borrowings - Interest Rates Nar

Borrowings - Interest Rates Narrative (Details)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	May 01, 2021
Sunoma Loan
Debt Instrument [Line Items]
Interest rate during period	8.60%	7.84%
Senior Secured Credit Facility
Debt Instrument [Line Items]
Weighed average effective interest rate		5.60%
Convertible Note Payable
Debt Instrument [Line Items]
Interest rate on loan		8%	8%
Municipality Loan
Debt Instrument [Line Items]
Weighed average effective interest rate		3%
OPAL Term Loan | Secured Debt
Debt Instrument [Line Items]
Weighed average effective interest rate	7.30%	8.40%

Borrowings - Schedule of Intere

Borrowings - Schedule of Interest Expense on Borrowings (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Debt Instrument [Line Items]
Convertible note payable mark-to-market	$ 0	$ 563
Commitment fees and other finance fees	688	128
Amortization of deferred financing cost	555	450
Interest expense on finance leases	147	16
Interest income	(666)	(1,261)
Total interest expense	3,961	641
Interest capitalized	1,444	1,808	$ 5,475
Equipment loan
Debt Instrument [Line Items]
Interest expense	5	0
Senior Secured Credit Facility
Debt Instrument [Line Items]
Interest expense	2	281
Convertible Note Payable mark-to-market
Debt Instrument [Line Items]
Convertible note payable mark-to-market	0	563
Sunoma Loan
Debt Instrument [Line Items]
Interest expense	461	445
OPAL Term Loan
Debt Instrument [Line Items]
Interest expense	$ 2,769	$ 19

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Thousands		3 Months Ended
	Dec. 27, 2023 uSD_Per_Gasoline_Gallon_Equivalent	Mar. 31, 2024 USD ($) vehicle lease facility	Sep. 30, 2023 facility	Mar. 31, 2023 USD ($)	Jan. 01, 2022 agreement
Operating Leased Assets [Line Items]
Total revenues		$ 64,952		$ 42,957
Number of vehicles | vehicle		104
Power purchase agreements
Operating Leased Assets [Line Items]
Number of agreements | agreement					2
RNG Fuel
Operating Leased Assets [Line Items]
Number of facilities | facility		2	3
Fuel Station Services
Operating Leased Assets [Line Items]
Total revenues		$ 37,142		20,828
Fuel Station Services | Fuel Provider Agreements ("FPAs")
Operating Leased Assets [Line Items]
Total revenues		772		570
Renewable Power
Operating Leased Assets [Line Items]
Total revenues		10,083		15,380
Renewable Power | Power purchase agreements
Operating Leased Assets [Line Items]
Total revenues		$ 219		$ 331
Site leases
Operating Leased Assets [Line Items]
Rent per gasoline gallon equivalent (in dollars per gasoline gallon equivalent) | uSD_Per_Gasoline_Gallon_Equivalent	1
Number of leases | lease		3
Site leases | RNG Fuel
Operating Leased Assets [Line Items]
Number of facilities | facility		3
Office leases
Operating Leased Assets [Line Items]
Term of lease		36 months
Additional renewal term (in years)		24 months
Number of leases | lease		1

Leases - Right-of-Use Assets an

Leases - Right-of-Use Assets and Lease Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accrued expenses and other current liabilities (includes $861 and $647 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)		Accrued expenses and other current liabilities (includes $861 and $647 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, plant, and equipment, net (includes $26,254 and $26,626 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)		Property, plant, and equipment, net (includes $26,254 and $26,626 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other long-term liabilities (includes $1,297 and $211 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)		Other long-term liabilities (includes $1,297 and $211 at March 31, 2024 and December 31, 2023, respectively, related to consolidated VIEs)
Operating leases, Right-of-use assets	$ 12,137		$ 12,301
Finance leases	8,743		9,048
Total right-of-use assets	20,880		21,349
Operating lease liabilities - current portion	656		638
Lease liabilities - current portion	2,101		2,036
Operating lease liabilities - non-current portion	11,646		11,824
Lease liabilities - non-current portion	18,986		19,212
Total lease liabilities	21,087		21,248
Amortization of right-of-use assets - finance leases	234	$ 140
Interest expense on lease liabilities - finance leases	147	16
Total lease expense	$ 785	540
Weighted average remaining lease term (years)
Operating leases	19 years 2 months 12 days
Financing leases	6 years 9 months 18 days
Weighted average discount rate
Operating leases	7.85%
Financing leases	6.60%
Minimum
Lessee, Lease, Description [Line Items]
Discount rate for operating and finance leases	3.59%
Maximum
Lessee, Lease, Description [Line Items]
Discount rate for operating and finance leases	8.44%
Site leases
Lessee, Lease, Description [Line Items]
Operating leases, Right-of-use assets	$ 11,278		11,330
Finance leases	6,283		6,468
Operating lease liabilities - current portion	138		130
Lease liabilities - current portion, finance lease	583		571
Operating lease liabilities - non-current portion	11,178		11,222
Lease liabilities - non-current portion, finance lease	5,679		5,587
Lease expense	$ 283	263
Weighted average discount rate
Operating leases	7.60%
Financing leases	6.50%
Office leases
Lessee, Lease, Description [Line Items]
Operating leases, Right-of-use assets	$ 859		971
Operating lease liabilities - current portion	518		508
Operating lease liabilities - non-current portion	468		602
Lease expense	$ 121	$ 121
Weighted average discount rate
Operating leases	3.60%
Vehicles
Lessee, Lease, Description [Line Items]
Finance leases	$ 2,460		2,580
Lease liabilities - current portion, finance lease	862		827
Lease liabilities - non-current portion, finance lease	$ 1,661		$ 1,801
Weighted average discount rate
Financing leases	6.30%

Leases - Future Minimum Lease P

Leases - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Lessee, Lease, Description [Line Items]
Operating leases	7.85%
Financing leases	6.60%
2024	$ 2,970
2025	3,620
2026	2,949
2027	2,521
2028 and beyond	24,565
Future minimum lease payments	36,625
Total lease liabilities	21,087	$ 21,248
Operating lease liabilities - current portion	656	638
Lease liabilities - current portion	2,101	2,036
Operating lease liabilities - non-current portion	11,646	11,824
Lease liabilities - non-current portion	18,986	19,212
Discount based on incremental borrowing rate	$ 15,538
Site leases
Lessee, Lease, Description [Line Items]
Operating leases	7.60%
Financing leases	6.50%
2024, operating lease	$ 797
2024, finance lease	963
2025, operating lease	1,129
2025, finance lease	963
2026, operating lease	1,129
2026, finance lease	963
2027, operating lease	1,129
2027, finance lease	963
2028 and beyond, operating lease	20,310
2028 and beyond, finance lease	4,250
Future minimum lease payments, operating lease	24,494
Future minimum lease payments, finance lease	8,102
Lease liabilities, operating lease	11,316
Lease liabilities, finance lease	6,262
Operating lease liabilities - current portion	138	130
Lease liabilities - current portion, finance lease	583	571
Operating lease liabilities - non-current portion	11,178	11,222
Lease liabilities - non-current portion, finance lease	5,679	5,587
Discount based on incremental borrowing rate, operating lease	13,178
Discount based on incremental borrowing rate, finance lease	$ 1,840
Office leases
Lessee, Lease, Description [Line Items]
Operating leases	3.60%
2024, operating lease	$ 406
2025, operating lease	562
2026, operating lease	47
2027, operating lease	0
2028 and beyond, operating lease	0
Future minimum lease payments, operating lease	1,015
Lease liabilities, operating lease	986
Operating lease liabilities - current portion	518	508
Operating lease liabilities - non-current portion	468	602
Discount based on incremental borrowing rate, operating lease	$ 29
Vehicles
Lessee, Lease, Description [Line Items]
Financing leases	6.30%
2024, finance lease	$ 804
2025, finance lease	966
2026, finance lease	810
2027, finance lease	429
2028 and beyond, finance lease	5
Future minimum lease payments, finance lease	3,014
Lease liabilities, finance lease	2,523
Lease liabilities - current portion, finance lease	862	827
Lease liabilities - non-current portion, finance lease	1,661	$ 1,801
Discount based on incremental borrowing rate, finance lease	$ 491

Derivative Financial Instrume_3

Derivative Financial Instruments and Fair Value Measurements - Effect of Derivative Instruments on Statement of Operations (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments, net	$ 0	$ (66)
Derivatives designated as economic hedges
Derivative Instruments, Gain (Loss) [Line Items]
Commodity swaps - realized gain	178	371
Commodity swaps - unrealized (loss) gain	(96)	922
Swaption
Derivative Instruments, Gain (Loss) [Line Items]
Swaption	0	(66)
Commodity swap contracts | Derivatives designated as economic hedges
Derivative Instruments, Gain (Loss) [Line Items]
Change in fair value of derivative instruments, net	$ 82	$ 1,293

Derivative Financial Instrume_4

Derivative Financial Instruments and Fair Value Measurements - Narrative (Details) $ in Thousands	1 Months Ended			3 Months Ended
	Nov. 30, 2023 kWh uSD_per_Kilowatt_Hour	Nov. 30, 2022 uSD_per_Megawatt-Hour	Oct. 31, 2022 commodity_swap uSD_per_Megawatt-Hour	Mar. 31, 2024 USD ($) $ / shares yr	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Derivative [Line Items]
Long-term debt, excluding current portion | $				$ 194,770		$ 196,542
Change in fair value of derivative instruments, net | $				$ 0	$ (66)
Forward Contracts
Derivative [Line Items]
Derivative, term of contract	2 years
Average Contract Price (per MWh) | uSD_per_Kilowatt_Hour	0.0599
Sponsor Earnout Awards
Derivative [Line Items]
Warrants expiration period				5 years
OPAL Earnout Awards
Derivative [Line Items]
Warrants expiration period				2 years
Share price | Sponsor Earnout Awards
Derivative [Line Items]
Warrants, measurement input | $ / shares				5.02
Share price | OPAL Earnout Awards
Derivative [Line Items]
Warrants, measurement input | $ / shares				5.02
Expected volatility | Sponsor Earnout Awards
Derivative [Line Items]
Warrants, measurement input				0.550
Expected volatility | OPAL Earnout Awards
Derivative [Line Items]
Warrants, measurement input				0.45
Risk free interest rate | Sponsor Earnout Awards
Derivative [Line Items]
Warrants, measurement input				0.044
Risk free interest rate | OPAL Earnout Awards
Derivative [Line Items]
Warrants, measurement input				0.051
Expected term | Sponsor Earnout Awards
Derivative [Line Items]
Warrants, measurement input | yr				3.31
Expected term | OPAL Earnout Awards
Derivative [Line Items]
Warrants, measurement input | yr				9,000
Dividend yield | Sponsor Earnout Awards
Derivative [Line Items]
Warrants, measurement input				0
Dividend yield | OPAL Earnout Awards
Derivative [Line Items]
Warrants, measurement input				0
Weighted average cost of capital | OPAL Earnout Awards
Derivative [Line Items]
Warrants, measurement input				0.176
Minimum | Forward Contracts
Derivative [Line Items]
Notional Quantity per Year (“MWh”) | kWh	1,875
Minimum | Discount rate | Level 3
Derivative [Line Items]
Asset retirement obligation, measurement input				0.0575
Maximum | Forward Contracts
Derivative [Line Items]
Notional Quantity per Year (“MWh”) | kWh	2,145
Maximum | Discount rate | Level 3
Derivative [Line Items]
Asset retirement obligation, measurement input				0.085
Commodity swap contracts | NextEra
Derivative [Line Items]
Number of additional instruments held (in commodity swap) | commodity_swap			2
Derivative, term of contract		2 years	2 years
Average Contract Price (per MWh) | uSD_per_Megawatt-Hour		81.50
Commodity swap contracts | Minimum | NextEra
Derivative [Line Items]
Average Contract Price (per MWh) | uSD_per_Megawatt-Hour			65.50
Commodity swap contracts | Maximum | NextEra
Derivative [Line Items]
Average Contract Price (per MWh) | uSD_per_Megawatt-Hour			68.50
Sponsor Earnout Awards
Derivative [Line Items]
Change in fair value of derivative instruments, net | $				$ 403	$ 310

Derivative Financial Instrume_5

Derivative Financial Instruments and Fair Value Measurements - Summary of Commodity Swaps (Details)	24 Months Ended
	Dec. 31, 2024 MWh	Nov. 17, 2022 uSD_per_Megawatt-Hour	Oct. 17, 2022 uSD_per_Megawatt-Hour
Commodity Contract, Contract One
Derivative [Line Items]
Average Contract Price (per MWh) | uSD_per_Megawatt-Hour			68.50
Commodity Contract, Contract One | Forecast
Derivative [Line Items]
Notional Quantity per Year (“MWh”) | MWh	70,176
Commodity Contract, Contract Two
Derivative [Line Items]
Average Contract Price (per MWh) | uSD_per_Megawatt-Hour		81.50
Commodity Contract, Contract Two | Forecast
Derivative [Line Items]
Notional Quantity per Year (“MWh”) | MWh	35,088

Derivative Financial Instrume_6

Derivative Financial Instruments and Fair Value Measurements - Derivatives Fair Values on Balance Sheet (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Derivative financial assets, current portion	$ 537	$ 633
Commodity swap contracts | Derivatives designated as economic hedges
Derivative [Line Items]
Derivative financial assets, current portion	$ 537	$ 633

Derivative Financial Instrume_7

Derivative Financial Instruments and Fair Value Measurements - Other Derivative Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Derivative [Line Items]
Change in fair value of derivative instruments, net	$ 0	$ (66)
Other Derivatives
Derivative [Line Items]
Change in fair value of derivative instruments, net	403	3,999
Put option to Meteora
Derivative [Line Items]
Change in fair value of derivative instruments, net	0	(311)
Sponsor Earnout Awards
Derivative [Line Items]
Change in fair value of derivative instruments, net	403	310
OPAL Earnout Awards
Derivative [Line Items]
Change in fair value of derivative instruments, net	$ 0	$ 4,000

Derivative Financial Instrume_8

Derivative Financial Instruments and Fair Value Measurements - Assets and Liabilities Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Liabilities:
Asset retirement obligation	$ 6,880	$ 6,728
Assets:
Cash and cash equivalents and restricted cash - current and non-current	32,696	47,242	$ 39,822	$ 77,221
Fair Value, Recurring
Liabilities:
Asset retirement obligation	6,880	6,728
Earnout liabilities	1,497	1,900
Assets:
Cash and cash equivalents and restricted cash - current and non-current	32,696	47,242
Short term investments	5,975	9,875
Fair Value, Recurring | Money Market Funds
Assets:
Cash and cash equivalents and restricted cash - current and non-current	18,854	31,965
Fair Value, Recurring | Commodity swap contracts
Assets:
Derivative assets	537	633
Fair Value, Recurring | Level 1
Liabilities:
Asset retirement obligation	0	0
Earnout liabilities	0	0
Assets:
Cash and cash equivalents and restricted cash - current and non-current	32,696	47,242
Short term investments	5,975	9,875
Fair Value, Recurring | Level 1 | Commodity swap contracts
Assets:
Derivative assets	0	0
Fair Value, Recurring | Level 2
Liabilities:
Asset retirement obligation	0	0
Earnout liabilities	0	0
Assets:
Cash and cash equivalents and restricted cash - current and non-current	0	0
Short term investments	0	0
Fair Value, Recurring | Level 2 | Commodity swap contracts
Assets:
Derivative assets	537	633
Fair Value, Recurring | Level 3
Liabilities:
Asset retirement obligation	6,880	6,728
Earnout liabilities	1,497	1,900
Assets:
Cash and cash equivalents and restricted cash - current and non-current	0	0
Short term investments	0	0
Fair Value, Recurring | Level 3 | Commodity swap contracts
Assets:
Derivative assets	$ 0	$ 0

Related Parties - Narrative (De

Related Parties - Narrative (Details) $ in Thousands				1 Months Ended	3 Months Ended		8 Months Ended	12 Months Ended
	Oct. 10, 2023 USD ($)	Nov. 29, 2021 USD ($) subsidiary shares	Dec. 31, 2020 USD ($)	Aug. 31, 2021 USD ($) shares	Mar. 31, 2024 USD ($) commodity_swap	Mar. 31, 2023 USD ($)	Mar. 31, 2021	Dec. 31, 2023 USD ($) commodity_swap shares	Dec. 31, 2022 USD ($) shares
Related Party Transaction [Line Items]
Preferred dividends issued and outstanding units					$ 2,014
Paid in kind dividends						$ 2,108
Stock subscribed (in shares) | shares		1,000,000
Amount sold								$ 100,000	$ 100,000
Stock issued (in shares) | shares								1,000,000	1,000,000
Total revenues					64,952	42,957
Net loss from equity method investments					(4,206)	(705)
Selling, general, and administrative					$ 13,161	14,074
Commodity swap contracts
Related Party Transaction [Line Items]
Number of derivative instruments held | commodity_swap					2			2
RNG Fuel
Related Party Transaction [Line Items]
Total revenues					$ 17,727	6,749
Fuel Station Services
Related Party Transaction [Line Items]
Total revenues					37,142	20,828
Renewable Power
Related Party Transaction [Line Items]
Total revenues					10,083	15,380
Reynolds
Related Party Transaction [Line Items]
Percentage of ownership interest acquired				100%
Cash payments				$ 12,020
Related Party | RNG Fuel
Related Party Transaction [Line Items]
Total revenues					15,495	4,715
Related Party | Fuel Station Services
Related Party Transaction [Line Items]
Total revenues					7,741	1,493
Related Party | Renewable Power
Related Party Transaction [Line Items]
Total revenues					1,526	1,527
Related Party | Hillman
Related Party Transaction [Line Items]
Common units, shares issued (in shares) | shares		14
Total consideration from related parties		$ 30,000
Paid in kind dividends						655
Related Party | Reynolds | GREP
Related Party Transaction [Line Items]
Cash consideration				$ 1,570
Related Party | Pine Bend, Sunoma And Noble Road | Environmental Processing Fees
Related Party Transaction [Line Items]
Total revenues					2,339	585
Term of related party contract (in years)							10 years
Related Party | Fortistar | Interim Services Agreement
Related Party Transaction [Line Items]
Monthly fee, maximum	$ 50,000
Selling, general, and administrative					$ 150
Parent Company | Fortistar | Administrative Services Agreement
Related Party Transaction [Line Items]
Written notice of termination period (in days)			180 days
Service fees per year			$ 580
GREP
Related Party Transaction [Line Items]
Ownership percentage				20%	20%
Net loss from equity method investments					$ 71	$ 203
GREP | BioTown Biogas LLC (“Biotown”)
Related Party Transaction [Line Items]
Ownership percentage				50%
RNG Fuel | NextEra
Related Party Transaction [Line Items]
Minimum of environmental attributes to be sold, percentage		90%
RNG Fuel | Hillman | Related Party
Related Party Transaction [Line Items]
Number of noncontrolling interests in renewable natural gas project subsidiaries | subsidiary		4
Series A-1 preferred units | Related Party | Hillman
Related Party Transaction [Line Items]
Preferred units, shares issued (in shares) | shares		300,000
Preferred dividends issued and outstanding units					$ 604
Class B common stock | Related Party | Reynolds | GREP
Related Party Transaction [Line Items]
Equity investment held (in shares) | shares				1,570

Related Parties - Fees Upon Ent

Related Parties - Fees Upon Entering Into Management Services Agreement with Related Party and Various Balances for Related Parties (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Related Party Transaction [Line Items]
Selling, general, and administrative	$ 13,161	$ 14,074
Related Party
Assets:
Accounts receivable, related party	14,912		$ 18,696
Liabilities:
Accounts payable, related party	8,166		7,024
Related Party | Costar
Related Party Transaction [Line Items]
Selling, general, and administrative	1,337	1,466
Related Party | Costar | Staffing and management services
Related Party Transaction [Line Items]
Selling, general, and administrative	462	575
Related Party | Costar | Rent - fixed compensation
Related Party Transaction [Line Items]
Selling, general, and administrative	171	165
Related Party | Costar | IT services
Related Party Transaction [Line Items]
Selling, general, and administrative	704	$ 726
Liabilities:
Accounts payable, related party	247		209
Related Party | Equity Method Investment Entities
Liabilities:
Accounts payable, related party	6,737		5,692
Related Party | NextEra
Liabilities:
Accounts payable, related party	500		501
Related Party | Fortistar | Staffing and management services
Liabilities:
Accounts payable, related party	$ 682		$ 622

Reportable Segments and Geogr_3

Reportable Segments and Geographic Information - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2024 USD ($) segment	Mar. 31, 2023 USD ($)
Segment Reporting [Abstract]
Number of operating segments | segment	4
Number of reportable segments | segment	4
Reclassification [Line Items]
Total revenues	$ 64,952	$ 42,957
RNG Fuel
Reclassification [Line Items]
Total revenues	17,727	6,749
RNG Fuel | Revision of Prior Period, Reclassification, Adjustment
Reclassification [Line Items]
Total revenues		(5,445)
Renewable Power
Reclassification [Line Items]
Total revenues	$ 10,083	15,380
Renewable Power | Revision of Prior Period, Reclassification, Adjustment
Reclassification [Line Items]
Total revenues		$ 5,445

Reportable Segments and Geogr_4

Reportable Segments and Geographic Information - Schedule of Total Revenues by Segment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenues:
Total revenues	$ 64,952	$ 42,957
Equity Method Investment(s)
Revenues:
Total revenues	25,407	7,539
Other
Revenues:
Total revenues	342	17
Intersegment
Revenues:
Total revenues	(4,508)	(3,747)
Renewable Power
Revenues:
Total revenues	10,083	15,380
Renewable Power | Operating Segments
Revenues:
Total revenues	10,083	15,363
RNG Fuel
Revenues:
Total revenues	17,727	6,749
RNG Fuel | Operating Segments
Revenues:
Total revenues	42,792	14,288
Fuel Station Services
Revenues:
Total revenues	37,142	20,828
Fuel Station Services | Operating Segments
Revenues:
Total revenues	$ 41,650	$ 24,575

Reportable Segments and Geogr_5

Reportable Segments and Geographic Information - Schedule of Interest Expense on Borrowings (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Interest and Financing Expense, Net:	$ (3,961)	$ (641)
Equity Method Investment(s)
Segment Reporting Information [Line Items]
Interest and Financing Expense, Net:	116	66
Renewable Power | Operating Segments
Segment Reporting Information [Line Items]
Interest and Financing Expense, Net:	60	(264)
RNG Fuel | Operating Segments
Segment Reporting Information [Line Items]
Interest and Financing Expense, Net:	(4,291)	(655)
Fuel Station Services | Operating Segments
Segment Reporting Information [Line Items]
Interest and Financing Expense, Net:	23	10
Corporate | Operating Segments
Segment Reporting Information [Line Items]
Interest and Financing Expense, Net:	$ 131	$ 202

Reportable Segments and Geogr_6

Reportable Segments and Geographic Information - Schedule of Depreciation, Amortization and Accretion (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Depreciation, Amortization, and Accretion:	$ 3,711	$ 3,567
Equity Method Investment(s)
Segment Reporting Information [Line Items]
Depreciation, Amortization, and Accretion:	(954)	(715)
Other
Segment Reporting Information [Line Items]
Depreciation, Amortization, and Accretion:	0	16
Renewable Power | Operating Segments
Segment Reporting Information [Line Items]
Depreciation, Amortization, and Accretion:	1,000	1,452
RNG Fuel | Operating Segments
Segment Reporting Information [Line Items]
Depreciation, Amortization, and Accretion:	2,346	2,024
Fuel Station Services | Operating Segments
Segment Reporting Information [Line Items]
Depreciation, Amortization, and Accretion:	$ 1,319	$ 790

Reportable Segments and Geogr_7

Reportable Segments and Geographic Information - Schedule of Net Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss)	$ 677	$ (7,346)
Equity Method Investment(s)	4,206	705
Renewable Power | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss)	(73)	4,542
RNG Fuel | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss)	2,925	(4,268)
Fuel Station Services | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss)	5,722	41
Corporate | Operating Segments
Segment Reporting, Reconciling Item for Operating Profit (Loss) from Segment to Consolidated [Line Items]
Net income (loss)	$ (12,103)	$ (8,366)

Reportable Segments and Geogr_8

Reportable Segments and Geographic Information - Schedule of Cash Paid for Purchases of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Segment Reporting Information [Line Items]
Cash paid for Purchases of Property, Plant, and Equipment:	$ 26,752	$ 38,780
Operating Segments | Fuel Station Services
Segment Reporting Information [Line Items]
Cash paid for Purchases of Property, Plant, and Equipment:	3,795	5,665
Operating Segments | RNG Fuel
Segment Reporting Information [Line Items]
Cash paid for Purchases of Property, Plant, and Equipment:	$ 22,957	$ 33,115

Reportable Segments and Geogr_9

Reportable Segments and Geographic Information - Total Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets:	$ 750,499	$ 754,609	$ 606,702
Equity Method Investment(s)	206,014	$ 207,099	50,570
Operating Segments | Renewable Power
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets:	36,266		46,199
Operating Segments | RNG Fuel
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets:	332,204		347,591
Operating Segments | Fuel Station Services
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets:	150,739		110,113
Operating Segments | Corporate
Segment Reporting, Asset Reconciling Item [Line Items]
Total Assets:	$ 25,276		$ 52,229

Variable Interest Entities - Na

Variable Interest Entities - Narrative (Details) - variable_interest_entity	Mar. 31, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of variable interest entities	7	7
Number of variable interest entities consolidated	2	2

Variable Interest Entities - Sc

Variable Interest Entities - Schedule of Variable Interest Entities on Consolidated Balance Sheets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 28,207	$ 38,348
Accounts receivable, net	22,805	27,623
Restricted cash - current	1,012	4,395
Parts inventory	11,135	10,191
Prepaid expenses and other current assets	6,373	6,005
Total current assets	105,699	128,073
Property, plant and equipment, net	359,369	339,493
Restricted cash, non-current	3,477	4,499
Total assets	750,499	754,609	$ 606,702
Current liabilities:
Other current liabilities	94	92
Sunoma Loan- current portion	1,652	1,608
Total current liabilities	75,354	74,343
Sunoma loan, net of debt issuance costs	19,609	20,010
Other long-term liabilities	8,637	7,599
Total liabilities	296,972	297,124
Equity
Stockholders' equity	(382,387)	(478,807)
Non-redeemable non-controlling interests	724	955
Total Stockholders' deficit	(381,663)	(477,852)	(791,386)	$ (774,156)
Total liabilities, Redeemable preferred non-controlling interests, Redeemable non-controlling interests and Stockholders' deficit	750,499	754,609
Related Party
Current liabilities:
Accounts payable	8,166	7,024
Non-redeemable non-controlling interests
Equity
Total Stockholders' deficit	724	955	$ 27,969	$ 26,445
Primary Beneficiary
Current assets:
Cash and cash equivalents	1,160	166
Accounts receivable, net	334	33
Restricted cash - current	1,012	4,395
Parts inventory	29	29
Prepaid expenses and other current assets	113	107
Total current assets	2,648	4,730
Property, plant and equipment, net	26,254	26,626
Restricted cash, non-current	1,957	1,850
Total assets	30,859	33,206
Current liabilities:
Accounts payable	11	744
Accrued expenses	861	647
Other current liabilities	94	92
Sunoma Loan- current portion	1,652	1,608
Total current liabilities	3,420	4,137
Sunoma loan, net of debt issuance costs	19,609	20,010
Other long-term liabilities	1,297	211
Total liabilities	24,326	24,358
Equity
Stockholders' equity	5,809	7,893
Non-redeemable non-controlling interests	724	955
Total Stockholders' deficit	6,533	8,848
Total liabilities, Redeemable preferred non-controlling interests, Redeemable non-controlling interests and Stockholders' deficit	30,859	33,206
Primary Beneficiary | Related Party
Current liabilities:
Accounts payable	$ 802	$ 1,046

Redeemable non-controlling in_3

Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' (Deficit) Equity - Narrative (Details) $ / shares in Units, $ in Thousands					1 Months Ended	3 Months Ended		12 Months Ended		20 Months Ended
	Mar. 12, 2024 vote_per_share vote shares	Nov. 17, 2023 USD ($)	Jul. 21, 2022 shares	Nov. 29, 2021 project shares	Jan. 31, 2024 USD ($) $ / shares shares	Mar. 31, 2024 USD ($) dividend_payment $ / shares shares	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) shares	Mar. 31, 2024 USD ($) $ / shares shares
Preferred Units [Line Items]
Stock issued (in shares)								1,000,000	1,000,000
Proceeds from issuance of shares of Class A common stock under the ATM program, net | $						$ 97	$ 0
Conversion of stock (in shares)				300,000
Number of noncontrolling interests in renewable natural gas project subsidiaries | project				4
Stock subscribed (in shares)				1,000,000
Amount sold | $								$ 100,000	$ 100,000
Preferred stock dividend rate						8%
Preferred stock, number of dividend payments to elect to issue additional Preferred Units | dividend_payment						8
Preferred stock dividend rate, event of default						12%
Preferred stock dividend rate, event of default, increase for each event						2%
Preferred stock dividend rate, event of default, maximum after increases						20%
Preferred stock liquidation preference (in dollars per share) | $ / shares						$ 100				$ 100
Preferred stock redemption price (in dollars per share) | $ / shares						$ 100				100
Preferred stock redemption period after which redeemable						4 years
Preferred stock redemption period after fourth anniversary						30 days
Preferred stock dividend rate if failed to redeem						12%
Preferred stock dividend rate, increase to after one year if failed to redeem						14%
Preferred stock dividend rate, quarterly increase after one year if failed to redeem						2%
Preferred stock dividend rate if failed to redeem, maximum						20%
Preferred stock conversion price (in dollars per share) | $ / shares						$ 100				100
Preferred stock conversion, first year discount						20%
Preferred stock conversion, second year discount						25%
Preferred stock conversion, thereafter discount						30%
Preferred stock conversion, VWAP period						20 days
Redemption price (in dollars per share) | $ / shares						$ 4.88				$ 4.88
Fortistar
Preferred Units [Line Items]
Number of votes per share | vote_per_share	5
Common stock, number of votes per share | vote	1
B. Riley Securities, Inc., Cantor Fitzgerald & Co. And Stifel, Nicolaus & Company, Incorporated ("Agent") | Scenario, Plan
Preferred Units [Line Items]
Aggregate offering price, up to | $		$ 75,000
Class A common stock
Preferred Units [Line Items]
Common stock, shares issued (in shares)						30,022,288		29,701,146		30,022,288
Common stock, shares outstanding (in shares)						30,022,288		29,701,146		30,022,288
Class A common stock | B. Riley Securities, Inc., Cantor Fitzgerald & Co. And Stifel, Nicolaus & Company, Incorporated ("Agent")
Preferred Units [Line Items]
Percentage of gross proceeds on each sale		3%
Stock issued (in shares)					14,005
Proceeds from issuance of shares of Class A common stock under the ATM program, net | $					$ 97
Class A common stock | B. Riley Securities, Inc., Cantor Fitzgerald & Co. And Stifel, Nicolaus & Company, Incorporated ("Agent") | Minimum
Preferred Units [Line Items]
Sales price (in dollars per share) | $ / shares					$ 5.40
Class A common stock | B. Riley Securities, Inc., Cantor Fitzgerald & Co. And Stifel, Nicolaus & Company, Incorporated ("Agent") | Maximum
Preferred Units [Line Items]
Sales price (in dollars per share) | $ / shares					$ 5.68
Class B common stock
Preferred Units [Line Items]
Common stock, shares issued (in shares)						71,500,000		0		71,500,000
Common stock, shares outstanding (in shares)						71,500,000		0		71,500,000
Class B common stock | Fortistar
Preferred Units [Line Items]
Common stock, shares outstanding (in shares)	71,500,000
Class C common stock
Preferred Units [Line Items]
Common stock, shares issued (in shares)						0		0		0
Common stock, shares outstanding (in shares)						0		0		0
Class D common stock
Preferred Units [Line Items]
Common stock, shares issued (in shares)						72,899,037		144,399,037		72,899,037
Common stock, shares outstanding (in shares)						72,899,037		144,399,037		72,899,037
Class D common stock | Fortistar
Preferred Units [Line Items]
Common stock, shares outstanding (in shares)	72,899,037
Shares conversion (in shares)	71,500,000
Class B Ordinary Share | Opal Fuels
Preferred Units [Line Items]
Stock issued (in shares)			144,399,037
Redeemable non-controlling interests
Preferred Units [Line Items]
Change in redemption value of Redeemable non-controlling interests | $						$ (97,044)	$ 7,720			$ 705,190

Redeemable non-controlling in_4

Redeemable non-controlling interests, Redeemable preferred non-controlling interests and Stockholders' (Deficit) Equity - Changes in Redeemable Preferred Units (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Redeemable Preferred non-controlling interests
Increase (Decrease) In Temporary Equity, Amount [Roll Forward]
Beginning balance	$ 132,617	$ 138,142
Preferred dividends attributable to OPAL Fuels	2,192
Preferred dividends attributable to Class A common stockholders	426
Payment of Preferred dividends	(5,235)	2,763
Ending balance	$ 130,000	$ 140,905
Series A-1 preferred units
Increase (Decrease) In Temporary Equity, Units [Roll Forward]
Beginning balance (in shares)	300,000
Ending balance (in shares)	300,000
Increase (Decrease) In Temporary Equity, Amount [Roll Forward]
Beginning balance	$ 30,604
Preferred dividends attributable to OPAL Fuels	506
Preferred dividends attributable to Class A common stockholders	98
Payment of Preferred dividends	(1,208)
Ending balance	$ 30,000
Series A preferred units
Increase (Decrease) In Temporary Equity, Units [Roll Forward]
Beginning balance (in shares)	1,000,000
Ending balance (in shares)	1,000,000
Increase (Decrease) In Temporary Equity, Amount [Roll Forward]
Beginning balance	$ 102,013
Preferred dividends attributable to OPAL Fuels	1,686
Preferred dividends attributable to Class A common stockholders	328
Payment of Preferred dividends	(4,027)
Ending balance	$ 100,000

Net Income (Loss) Per Share - N

Net Income (Loss) Per Share - Narrative (Details) - shares	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Treasury Stock, Common
Class of Warrant or Right [Line Items]
Antidilutive shares (in shares)	1,635,783	1,635,783
Class A common stock
Class of Warrant or Right [Line Items]
Forfeited shares (in shares)		197,258
Class B common stock
Class of Warrant or Right [Line Items]
Antidilutive shares (in shares)	144,399,037	144,399,037
Earnout Target
Class of Warrant or Right [Line Items]
Antidilutive shares (in shares)	763,908	763,908
Sponsor Earnout Awards
Class of Warrant or Right [Line Items]
Antidilutive shares (in shares)	716,650	763,908
OPAL Earnout Awards
Class of Warrant or Right [Line Items]
Antidilutive shares (in shares)	10,000,000	10,000,000

Net Income (Loss) Per Share - S

Net Income (Loss) Per Share - Schedule of Basic and Diluted Net Loss Per Unit (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Earnings Per Share [Abstract]
Net loss attributable to Class A common stockholders	$ (316)	$ (1,579)
Weighted average number of shares of Class A common stock - basic (in shares)	27,368,204	27,383,562
Dilutive effect of stock options, restricted stock units, performance units, Convertible note payable, earnout shares, Redeemable preferred non-controlling interests, Redeemable non-controlling interests (in shares)	0	0
Weighted average number of shares of Class A common stock - diluted (in shares)	27,368,204	27,383,562
Net loss per share of Class A common stock
Basic (in dollars per share)	$ (0.01)	$ (0.06)
Diluted (in dollars per share)	$ (0.01)	$ (0.06)

Income taxes (Details)

Income taxes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Income Tax Disclosure [Abstract]
Provision for income taxes	$ 0	$ 0
Effective tax rate	0%	0%

Stock-based compensation - Narr

Stock-based compensation - Narrative (Details) - USD ($)		3 Months Ended	12 Months Ended
	Jul. 21, 2022	Mar. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock issued (in shares)			1,000,000	1,000,000
Granted (in shares)		360,298
Weighted average exercise price (in dollars per share)		$ 3.40
Closing share price (in dollars per share)		4.96
Exercise price (in dollars per share)		$ 5.02
Fair value		$ 9,971,000
Vested and exercisable (in shares)		62,327	0
Aggregate intrinsic value		$ 0	$ 0
Certain Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)		360,298
Restricted Stock Units (RSUs)
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)		1,300,557
Restricted Stock Units (RSUs) | Certain Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)		1,110,031
Restricted Stock Units (RSUs) | Director
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)		190,526
Vesting percentage		100%
Performance Shares
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)		456,308
Vesting percentage		100%	100%
Performance Shares | Certain Employees
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Granted (in shares)		456,308
Stock Options
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Expiration term (in years)		10 years
Annual risk free interest rate		3.96%
Volatility		55%
2022 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock issued (in shares)	19,811,726

Stock-based compensation - Summ

Stock-based compensation - Summary of Equity Awards Under 2022 Plan (Details) $ / shares in Units, $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2024 USD ($) installment $ / shares shares	Dec. 31, 2023 USD ($) installment $ / shares shares
Stock Options
Unvested stock options, beginning balance (in shares) | shares	175,890
Granted (in shares) | shares	360,298
Unvested stock options, ending balance (in shares) | shares	536,188	175,890
Vested and exercisable (in shares) | shares	62,327	0
Weighted average fair value per stock options on grant date
Weighted average fair value per stock option on grant date, beginning balance (in dollars per share)	$ 5.26
Granted, Weighted average fair value per stock option on grant date (in dollars per share)	3.40
Weighted average fair value per stock option on grant date, ending balance (in dollars per share)	4.01	$ 5.26
Vested and exercisable, Weighted average fair value per stock option on grant date (in dollars per share)	5.26
Exercise price per Stock Option
Exercise price per Stock Option, beginning balance (in dollars per share)	6.97
Granted, Exercise price per Stock Option (in dollars per share)	5.02
Exercise price per Stock Option, ending balance (in dollars per share)	5.66	$ 6.97
Vested and exercisable, Exercise price per Stock Option (in dollars per share)	$ 6.97
Aggregate fair value
Beginning balance | $	$ 925
Granted | $	1,225
Ending balance | $	2,150	$ 925
Vested and exercisable | $	$ 328
Total unvested awards outstanding (in shares) | shares	3,120,722
Total unvested awards outstanding, Weighted Average Grant Date Fair Value (in dollars per share)	$ 5.31
Total unvested awards outstanding, Aggregate fair value | $	$ 16,565
Restricted Stock Units (RSUs)
Restricted Stock Units and Performance Stock Units
Beginning balance (in shares) | shares	949,936
Granted (in shares) | shares	1,300,557
Vested (in shares) | shares	(307,137)
Withheld for settlement of taxes (in shares) | shares	(112,402)
Forfeitures (in shares) | shares	(2,870)
Ending balance (in shares) | shares	1,828,084	949,936
Weighted average fair value per unit on grant date
Weighted average fair value per unit on grant date, beginning balance (in dollars per share)	$ 6.98
Granted, Weighted average fair value per unit on grant date (in dollars per share)	4.98
Vested, Weighted average fair value per unit on grant date (in dollars per share)	6.97
Withheld for settlement of taxes, Weighted average fair value per unit on grant date (in dollars per share)	6.97
Forfeitures, Weighted average fair value per unit on grant date (in dollars per share)	6.97
Weighted average fair value per unit on grant date, ending balance (in dollars per share)	$ 5.56	$ 6.98
Aggregate fair value
Beginning balance | $	$ 6,627
Granted | $	6,479
Vested | $	(2,141)
Withheld for settlement of taxes | $	(783)
Forfeitures | $	(20)
Ending balance | $	$ 10,162	$ 6,627
Restricted Stock Units (RSUs) | Minimum
Aggregate fair value
Vesting term (in years)	1 year	1 year
Restricted Stock Units (RSUs) | Maximum
Aggregate fair value
Vesting term (in years)	3 years	3 years
Stock Options
Aggregate fair value
Number of installments | installment	3	3
Vesting term (in years)	3 years	3 years
Expiration term (in years)	10 years
Performance Shares
Restricted Stock Units and Performance Stock Units
Beginning balance (in shares) | shares	239,680
Granted (in shares) | shares	456,308
Forfeitures (in shares) | shares	(1,865)
Ending balance (in shares) | shares	694,123	239,680
Weighted average fair value per unit on grant date
Weighted average fair value per unit on grant date, beginning balance (in dollars per share)	$ 6.97
Granted, Weighted average fair value per unit on grant date (in dollars per share)	4.97
Forfeitures, Weighted average fair value per unit on grant date (in dollars per share)	6.97
Weighted average fair value per unit on grant date, ending balance (in dollars per share)	$ 5.65	$ 6.97
Aggregate fair value
Beginning balance | $	$ 1,671
Granted | $	2,267
Forfeitures | $	(13)
Ending balance | $	$ 3,925	$ 1,671
Aggregate fair value
Vesting percentage	100%	100%

Stock-based compensation - Stoc

Stock-based compensation - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense	$ 1,013	$ 971
2022 Plan
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense	853	811
Parent equity awards
Share-Based Compensation Arrangement by Share-Based Payment Award [Line Items]
Stock-based compensation expense	$ 160	$ 160

Commitments and Contingencies (

Commitments and Contingencies (Details) $ in Thousands	1 Months Ended	3 Months Ended	23 Months Ended
	Jul. 31, 2015	Mar. 31, 2024 USD ($) standby_letters_of_credit contract	May 10, 2024 USD ($)	Dec. 31, 2023 USD ($) standby_letters_of_credit
Line of Credit Facility [Line Items]
Number of standby letters of credit held | standby_letters_of_credit		11		11
VEC Partners, Inc. dba CEI Builders (“CEI”) | MD Digester, LLC
Line of Credit Facility [Line Items]
Estimated loss per contract		$ 14,000
Estimated loss from claim		$ 28,000
Compressed Natural Gas (CNG)
Line of Credit Facility [Line Items]
Number of purchase option contracts to provide CNG | contract		2
Compressed Natural Gas (CNG) | Minimum
Line of Credit Facility [Line Items]
Term of purchase option contract (in years)		7 years
Compressed Natural Gas (CNG) | Maximum
Line of Credit Facility [Line Items]
Term of purchase option contract (in years)		10 years
Fuel
Line of Credit Facility [Line Items]
Term of purchase option contract (in years)	10 years
Standby Letters of Credit
Line of Credit Facility [Line Items]
Standby letters of credit outstanding balance		$ 14,637		$ 14,783
Standby Letters of Credit | Subsequent Event
Line of Credit Facility [Line Items]
Draws on standby letters of credit			$ 0