Clean Energy Fuels (CLNE) 10-Q 8 Nov 22 2022 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2022	Nov. 01, 2022
Document and Entity Information
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Sep. 30, 2022
Document Fiscal Year Focus	2022
Entity File Number	001-33480
Entity Registrant Name	CLEAN ENERGY FUELS CORP.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0968580
Entity Address, Address Line One	4675 MacArthur Court
Entity Address, Address Line Two	Suite 800
Entity Address, City or Town	Newport Beach
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92660
City Area Code	949
Local Phone Number	437-1000
Title of 12(b) Security	Common Stock
Trading Symbol	CLNE
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding (in shares)		222,428,143
Entity Central Index Key	0001368265
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q3
Amendment Flag	false

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 23,123	$ 99,448
Short-term investments	110,989	129,722
Accounts receivable, net of allowance of $1,205 and $0,000 as of December 31, 2021 and September 30, 2022, respectively	92,161	87,433
Other receivables	35,112	24,447
Inventory	35,927	31,302
Prepaid expenses and other current assets	58,262	37,584
Total current assets	355,574	409,936
Operating lease right-of-use assets	45,144	42,537
Land, property and equipment, net	248,902	261,761
Restricted cash		7,008
Notes receivable and other long-term assets, net	28,155	56,189
Investments in other entities	193,428	109,811
Goodwill	64,328	64,328
Intangible assets, net	5,915	5,500
Total assets	941,446	957,070
Current liabilities:
Current portion of debt	4,165	12,845
Current portion of finance lease obligations	939	846
Current portion of operating lease obligations	3,920	3,551
Accounts payable	31,038	24,352
Accrued liabilities	85,200	75,159
Deferred revenue	4,927	7,251
Derivative liabilities, related party	3,912	1,900
Total current liabilities	134,101	125,904
Long-term portion of debt	24,390	23,215
Long-term portion of finance lease obligations	2,223	2,427
Long-term portion of operating lease obligations	41,682	39,431
Long-term portion of derivative liabilities, related party	1,694	2,483
Other long-term liabilities	8,633	8,199
Total liabilities	212,723	201,659
Commitments and contingencies (Note 17)
Stockholders' equity:
Preferred stock, $0.0001 par value. 1,000,000 shares authorized; no shares issued and outstanding	0	0
Common stock, $0.0001 par value. 454,000,000 shares authorized; 222,684,923 shares and 222,177,172 shares issued and outstanding as of December 31, 2021 and September 30, 2022, respectively	22	22
Additional paid-in capital	1,543,511	1,519,918
Accumulated deficit	(817,641)	(771,242)
Accumulated other comprehensive loss	(4,877)	(1,622)
Total Clean Energy Fuels Corp. stockholders' equity	721,015	747,076
Noncontrolling interest in subsidiary	7,708	8,335
Total stockholders' equity	728,723	755,411
Total liabilities and stockholders' equity	$ 941,446	$ 957,070

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 1,457	$ 1,205
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, authorized (in shares)	1,000,000	1,000,000
Preferred stock, issued (in shares)	0	0
Preferred stock, outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, authorized (in shares)	454,000,000	454,000,000
Common stock, issued (in shares)	222,413,908	222,684,923
Common stock, outstanding (in shares)	222,177,172	222,684,923

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue:
Total revenue	$ 125,687	$ 86,095	$ 306,408	$ 163,718
Cost of sales (exclusive of depreciation and amortization shown separately below):
Selling, general and administrative	26,501	22,303	80,909	65,350
Depreciation and amortization	20,539	11,092	42,485	34,208
Total operating expenses	134,315	89,196	346,966	252,671
Operating loss	(8,628)	(3,101)	(40,558)	(88,953)
Interest expense	(670)	(1,038)	(4,479)	(3,476)
Interest income	1,019	334	1,773	828
Other income, net	25	62	59	906
Income (loss) from equity method investments	(728)	(355)	(3,598)	(660)
Loss before income taxes	(8,982)	(4,098)	(46,803)	(91,355)
Income tax expense	(106)	(60)	(223)	(199)
Net loss	(9,088)	(4,158)	(47,026)	(91,554)
Loss attributable to noncontrolling interest	115	224	627	784
Net loss attributable to Clean Energy Fuels Corp.	$ (8,973)	$ (3,934)	$ (46,399)	$ (90,770)
Net loss attributable to Clean Energy Fuels Corp. per share:
Basic (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.21)	$ (0.43)
Diluted (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.21)	$ (0.43)
Weighted-average common shares outstanding:
Basic (in shares)	222,239,376	223,008,202	222,409,802	209,771,584
Diluted (in shares)	222,239,376	223,008,202	222,409,802	209,771,584
Product revenue
Revenue:
Total revenue	$ 113,360	$ 74,354	$ 271,720	$ 133,081
Cost of sales (exclusive of depreciation and amortization shown separately below):
Cost of sales	79,710	48,254	203,258	134,356
Service revenue
Revenue:
Total revenue	12,327	11,741	34,688	30,637
Cost of sales (exclusive of depreciation and amortization shown separately below):
Cost of sales	$ 7,565	$ 7,547	$ 20,314	$ 18,757

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net loss	$ (9,088)	$ (4,158)	$ (47,026)	$ (91,554)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of $0 tax in 2021 and 2022	(1,901)	(838)	(2,926)	(999)
Unrealized losses on available-for-sale securities, net of $0 tax in 2021 and 2022	(187)	(26)	(329)	(29)
Total other comprehensive income (loss)	(2,088)	(864)	(3,255)	(1,028)
Comprehensive loss	(11,176)	(5,022)	(50,281)	(92,582)
Clean Energy Fuels Corp.
Net loss	(8,973)	(3,934)	(46,399)	(90,770)
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of $0 tax in 2021 and 2022	(1,901)	(838)	(2,926)	(999)
Unrealized losses on available-for-sale securities, net of $0 tax in 2021 and 2022	(187)	(26)	(329)	(29)
Total other comprehensive income (loss)	(2,088)	(864)	(3,255)	(1,028)
Comprehensive loss	(11,061)	(4,798)	(49,654)	(91,798)
Noncontrolling Interest in Subsidiary
Net loss	(115)	(224)	(627)	(784)
Other comprehensive income (loss), net of tax:
Comprehensive loss	$ (115)	$ (224)	$ (627)	$ (784)

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Statement of Comprehensive Income [Abstract]
Foreign currency translation adjustment, tax	$ 0	$ 0	$ 0	$ 0
Unrealized gains on available-for sale securities, tax	$ 0	$ 0	$ 0	$ 0

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Common stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss	Noncontrolling Interest in Subsidiary	Total
Beginning balance at Dec. 31, 2020	$ 20	$ 1,191,791	$ (678,096)	$ (209)	$ 9,344	$ 522,850
Beginning balance (in shares) at Dec. 31, 2020	198,491,204
Increase (Decrease) in Stockholders' Equity
Issuance of common stock		3,216				3,216
Issuance of common stock (in shares)	1,323,814
Stock-based compensation		3,367				3,367
Net loss			(7,169)		(278)	(7,447)
Other comprehensive income (loss)				(880)		(880)
Ending balance at Mar. 31, 2021	$ 20	1,198,374	(685,265)	(1,089)	9,066	521,106
Ending balance (in shares) at Mar. 31, 2021	199,815,018
Beginning balance at Dec. 31, 2020	$ 20	1,191,791	(678,096)	(209)	9,344	522,850
Beginning balance (in shares) at Dec. 31, 2020	198,491,204
Increase (Decrease) in Stockholders' Equity
Net loss					(784)	(91,554)
Other comprehensive income (loss)						(1,028)
Ending balance at Sep. 30, 2021	$ 22	1,516,452	(768,866)	(1,237)	8,560	754,931
Ending balance (in shares) at Sep. 30, 2021	223,085,469
Beginning balance at Mar. 31, 2021	$ 20	1,198,374	(685,265)	(1,089)	9,066	521,106
Beginning balance (in shares) at Mar. 31, 2021	199,815,018
Increase (Decrease) in Stockholders' Equity
Issuance of common stock	$ 2	194,171				194,173
Issuance of common stock (in shares)	23,151,937
Stock-based compensation		3,419				3,419
Stock-based sales incentive charges		115,778				115,778
Net loss			(79,667)		(282)	(79,949)
Other comprehensive income (loss)				716		716
Ending balance at Jun. 30, 2021	$ 22	1,511,742	(764,932)	(373)	8,784	755,243
Ending balance (in shares) at Jun. 30, 2021	222,966,955
Increase (Decrease) in Stockholders' Equity
Issuance of common stock		390				390
Issuance of common stock (in shares)	118,514
Stock-based compensation		3,434				3,434
Stock-based sales incentive charges		886				886
Net loss			(3,934)		(224)	(4,158)
Other comprehensive income (loss)				(864)		(864)
Ending balance at Sep. 30, 2021	$ 22	1,516,452	(768,866)	(1,237)	8,560	754,931
Ending balance (in shares) at Sep. 30, 2021	223,085,469
Beginning balance at Dec. 31, 2021	$ 22	1,519,918	(771,242)	(1,622)	8,335	$ 755,411
Beginning balance (in shares) at Dec. 31, 2021	222,684,923					222,684,923
Increase (Decrease) in Stockholders' Equity
Issuance of common stock		273				$ 273
Issuance of common stock (in shares)	585,775
Repurchase of common stock		(3,001)				(3,001)
Repurchase of common stock (in shares)	(511,010)
Stock-based compensation		8,253				8,253
Stock-based sales incentive charges		1,721				1,721
Net loss			(24,191)		(385)	(24,576)
Other comprehensive income (loss)				249		249
Ending balance at Mar. 31, 2022	$ 22	1,527,164	(795,433)	(1,373)	7,950	738,330
Ending balance (in shares) at Mar. 31, 2022	222,759,688
Beginning balance at Dec. 31, 2021	$ 22	1,519,918	(771,242)	(1,622)	8,335	$ 755,411
Beginning balance (in shares) at Dec. 31, 2021	222,684,923					222,684,923
Increase (Decrease) in Stockholders' Equity
Repurchase of common stock						$ (6,100)
Repurchase of common stock (in shares)						(1,190,254)
Net loss					(627)	$ (47,026)
Other comprehensive income (loss)						(3,255)
Ending balance at Sep. 30, 2022	$ 22	1,543,511	(817,641)	(4,877)	7,708	$ 728,723
Ending balance (in shares) at Sep. 30, 2022	222,413,908					222,413,908
Beginning balance at Mar. 31, 2022	$ 22	1,527,164	(795,433)	(1,373)	7,950	$ 738,330
Beginning balance (in shares) at Mar. 31, 2022	222,759,688
Increase (Decrease) in Stockholders' Equity
Issuance of common stock		300				300
Issuance of common stock (in shares)	96,728
Repurchase of common stock		(3,121)				(3,121)
Repurchase of common stock (in shares)	(679,244)
Stock-based compensation		6,468				6,468
Stock-based sales incentive charges		2,307				2,307
Net loss			(13,235)		(127)	(13,362)
Other comprehensive income (loss)				(1,416)		(1,416)
Ending balance at Jun. 30, 2022	$ 22	1,533,118	(808,668)	(2,789)	7,823	729,506
Ending balance (in shares) at Jun. 30, 2022	222,177,172
Increase (Decrease) in Stockholders' Equity
Issuance of common stock		744				744
Issuance of common stock (in shares)	236,736
Stock-based compensation		5,964				5,964
Stock-based sales incentive charges		3,685				3,685
Net loss			(8,973)		(115)	(9,088)
Other comprehensive income (loss)				(2,088)		(2,088)
Ending balance at Sep. 30, 2022	$ 22	$ 1,543,511	$ (817,641)	$ (4,877)	$ 7,708	$ 728,723
Ending balance (in shares) at Sep. 30, 2022	222,413,908					222,413,908

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Cash flows from operating activities:
Net loss	$ (47,026)	$ (91,554)
Adjustments to reconcile net loss to net cash provided by operating activities:
Depreciation and amortization	42,485	34,208
Provision for credit losses and inventory	1,606	955
Stock-based compensation expense	20,685	10,220
Stock-based sales incentive charges	15,500	80,237
Change in fair value of derivative instruments	1,606	2,240
Amortization of discount and debt issuance cost	(862)	27
Loss (gain) on disposal of property and equipment	40	1,671
Loss on extinguishment of debt	2,268	25
Loss from equity method investments	3,598	660
Non-cash lease expense	2,602	2,219
Deferred income taxes	143	91
Changes in operating assets and liabilities:
Accounts and other receivables	(19,139)	(520)
Inventory	(7,601)	(3,255)
Prepaid expenses and other assets	1,583	(8,680)
Operating lease liabilities	(2,589)	(2,414)
Accounts payable	5,937	(181)
Deferred revenue	(2,324)	(667)
Accrued liabilities and other	13,216	7,561
Net cash provided by operating activities	31,728	32,843
Cash flows from investing activities:
Purchases of short-term investments	(292,930)	(194,976)
Maturities and sales of short-term investments	312,239	104,301
Purchases of and deposits on property and equipment	(29,091)	(20,197)
Disbursements for loans receivable	(810)	(3,828)
Payments on and proceeds from sales of loans receivable	480	362
Cash received from sale of certain assets of subsidiary, net	3,885	887
Investments in other entities	(89,700)	(50,669)
Payment and deposits on equipment and manure rights for RNG production projects	(4,915)	0
Proceeds from disposal of property and equipment	129	2,317
Net cash used in investing activities	(100,713)	(161,803)
Cash flows from financing activities:
Issuance of common stock	1,317	204,174
Repurchase of common stock	(6,122)	0
Fees paid for issuance of common stock		(6,534)
Fees paid for debt issuance costs	(50)	(1,263)
Proceeds for Adopt-a-Port program	1,100	4,840
Repayment of proceeds for Adopt-a-Port program	(828)	(126)
Proceeds from debt instruments	14,000	4,400
Proceeds from revolving line of credit	0	1,450
Repayments of borrowing under revolving line of credit	0	(1,450)
Repayments of debt instruments and finance lease obligations	(21,167)	(49,602)
Payments of debt extinguishment costs	(2,186)	(14)
Net cash provided by (used in) financing activities	(13,936)	155,875
Effect of exchange rates on cash, cash equivalents and restricted cash	(412)	20
Net increase (decrease) in cash, cash equivalents and restricted cash	(83,333)	26,935
Cash, cash equivalents and restricted cash, beginning of period	106,456	119,977
Cash, cash equivalents and restricted cash, end of period	23,123	146,912
Supplemental disclosure of cash flow information:
Income taxes paid	50	12
Interest paid, net of $0 and $0 capitalized, respectively	$ 1,373	$ 3,232

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Statement of Cash Flows [Abstract]
Capitalized interest paid, respectively	$ 0	$ 0

General

General	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
General	Note 1—General Nature of Business Clean Energy Fuels Corp., together with its majority and wholly owned subsidiaries (hereinafter collectively referred to as the “Company,” unless the context or the use of the term indicates or requires otherwise) is engaged in the business of selling renewable and conventional natural gas as alternative fuels for vehicle fleets and related fueling solutions to its customers, primarily in the United States and Canada. The Company’s principal business is supplying renewable natural gas (“RNG”) and conventional natural gas, in the form of compressed natural gas (“CNG”) and liquefied natural gas (“LNG”), for medium and heavy-duty vehicles and providing operation and maintenance (“O&M”) services for public and private vehicle fleet customer stations. The Company is also focused on developing, owning, and operating dairy and other livestock waste RNG projects and supplying RNG (currently procured solely from third party sources and will be supplemented by internally produced RNG when the Company’s RNG projects come online) to its customers in the heavy and medium-duty commercial transportation sector. As a comprehensive clean energy solution provider, the Company also designs and builds, as well as operates and maintains, public and private vehicle fueling stations in the United States and Canada; sells and services compressors and other equipment used in RNG production and at fueling stations; transports and sells RNG and conventional natural gas, in the form of CNG and LNG, via “virtual” natural gas pipelines and interconnects; sells U.S. federal, state and local government credits it generates by selling RNG in the form of CNG and LNG as a vehicle fuel, including Renewable Identification Numbers (“RIN Credits” or “RINs”) under the federal Renewable Fuel Standard Phase 2 and credits under the California and the Oregon Low Carbon Fuel Standards (collectively, “LCFS Credits”); and obtains federal, state and local tax credits, grants and incentives. Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries, and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to state fairly the Company’s consolidated financial position as of September 30, 2022, results of operations, comprehensive loss, and stockholders’ equity for the three and nine months ended September 30, 2021 and 2022, and cash flows for the nine months ended September 30, 2021 and 2022. All intercompany accounts and transactions have been eliminated in consolidation. The results of operations for the three and nine months ended September 30, 2021 and 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or any future year. Certain information and disclosures normally included in the notes to consolidated financial statements have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”), but the resultant disclosures contained herein are in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as they apply to interim reporting. The accompanying condensed consolidated financial statements should be read in conjunction with the consolidated financial statements as of and for the year ended December 31, 2021 that are included in the Company’s Annual Report on Form 10-K filed with the SEC on February 24, 2022. 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 amounts reported in the accompanying condensed consolidated financial statements and these notes. Actual results could differ from those estimates and may result in material effects on the Company’s operating results and financial position. Significant estimates made in preparing the accompanying condensed consolidated financial statements include (but are not limited to) those related to revenue recognition, fair value measurements, goodwill and long-lived asset valuations and impairment assessments, income tax valuations, stock-based compensation expense and stock-based sales incentive charges. Amazon Warrant The Amazon Warrant (defined in Note 14) is accounted for as an equity instrument and measured in accordance with Accounting Standards Codification (“ASC”) 718, Compensation – Stock Compensation Revenue from Contracts with Customers ​ Recently Adopted Accounting Pronouncements In July 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2021-05, Leases (Topic 842): Lessors–Certain Leases with Variable Lease Payments Recently Issued Accounting Pronouncements In November 2021, the FASB issued ASU No. 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance

Revenue from Contracts with Cus

Revenue from Contracts with Customers	9 Months Ended
	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Revenue from Contracts with Customers	Note 2—Revenue from Contracts with Customers Revenue Recognition Overview The Company recognizes revenue when control of the promised goods or services is transferred to its customers, in an amount that reflects the consideration to which it expects to be entitled in exchange for the goods or services. To achieve that core principle, a five-step approach is applied: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue allocated to each performance obligation when the Company satisfies the performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account for revenue recognition. The Company is generally the principal in its customer contracts because it has control over the goods and services prior to their transfer to the customer, and as such, revenue is recognized on a gross basis. Sales and usage-based taxes are excluded from revenue. Revenue is recognized net of allowances for returns and any taxes collected from customers, which are subsequently remitted to governmental authorities. The table below presents the Company’s revenue disaggregated by revenue source (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2021 2022 2021 2022 Product revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Volume-related ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fuel sales (1) ​ $ 52,343 ​ $ 78,512 ​ $ 72,237 ​ $ 204,224 Change in fair value of derivative instruments (2) ​ ​ 268 ​ ​ 508 ​ ​ (2,240) ​ ​ (1,606) RIN Credits ​ ​ 8,134 ​ ​ 9,270 ​ ​ 21,916 ​ ​ 26,997 LCFS Credits ​ ​ 5,744 ​ ​ 2,595 ​ ​ 12,976 ​ ​ 10,114 AFTC (3) ​ 5,287 ​ 16,057 ​ 15,008 ​ 16,279 Total volume-related product revenue ​ ​ 71,776 ​ ​ 106,942 ​ ​ 119,897 ​ ​ 256,008 Station construction sales ​ ​ 2,578 ​ ​ 6,418 ​ ​ 13,184 ​ ​ 15,712 Total product revenue ​ 74,354 ​ 113,360 ​ 133,081 ​ 271,720 Service revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Volume-related, O&M services ​ ​ 11,676 ​ ​ 11,982 ​ ​ 30,506 ​ ​ 33,727 Other services ​ ​ 65 ​ ​ 345 ​ ​ 131 ​ ​ 961 Total service revenue ​ ​ 11,741 ​ ​ 12,327 ​ ​ 30,637 ​ ​ 34,688 Total revenue ​ $ 86,095 ​ $ 125,687 ​ $ 163,718 ​ $ 306,408 (1) Includes non-cash stock-based sales incentive contra-revenue charges associated with the Amazon Warrant. For the three and nine months ended September 30, 2021, contra-revenue charges recognized in fuel revenue were $2.2 million and $80.2 million, respectively. For the three and nine months ended September 30, 2022, contra-revenue charges recognized in fuel revenue were $7.0 million and $15.5 million, respectively. See Note 14 for more information. (2) Represents changes in fair value of derivative instruments related to the Company’s commodity swap and customer fueling contracts associated with the Company’s Zero Now truck financing program. The amounts are classified as revenue because the Company’s commodity swap contracts are used to economically offset the risk associated with the diesel-to-natural gas price spread resulting from customer fueling contracts under the Company’s Zero Now truck financing program. See Note 6 for more information about these derivative instruments. (3) Represents the federal alternative fuel excise tax credit (“AFTC”), which was renewed and extended for three years beginning retroactively to January 1, 2022. See Note 19 for more information. Remaining Performance Obligations Remaining performance obligations represent the transaction price of customer orders for which the work has not been performed. As of September 30, 2022, the aggregate amount of the transaction price allocated to remaining performance obligations was $23.1 million, which related to the Company’s station construction sale contracts. The Company expects to recognize revenue on the remaining performance obligations under these contracts over the next 12 For volume-related revenue, the Company has elected to apply an optional exemption, which waives the requirement to disclose the remaining performance obligation for revenue recognized through the ‘ Contract Balances The timing of revenue recognition, billings and cash collections results in billed accounts receivable, unbilled receivables (contract assets), and customer advances and deposits (contract liabilities) in the accompanying condensed consolidated balance sheets. As of December 31, 2021 and September 30, 2022, the Company’s contract balances were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 ​ 2022 Accounts receivable, net ​ $ 87,433 ​ $ 92,161 ​ ​ ​ ​ ​ ​ Contract assets - current ​ $ 966 ​ $ 2,046 Contract assets - non-current ​ 3,532 ​ 3,115 Contract assets - total ​ $ 4,498 ​ $ 5,161 ​ ​ ​ ​ ​ ​ Contract liabilities - current ​ $ 5,523 ​ $ 4,583 Contract liabilities - non-current ​ — ​ — Contract liabilities - total ​ $ 5,523 ​ $ 4,583 ​ Accounts Receivable, Net "Accounts receivable, net" in the accompanying condensed consolidated balance sheets includes amounts billed and currently due from customers. The amounts due are stated at their net estimated realizable value. The Company maintains an allowance to provide for the estimated amount of receivables that will not be collected. The allowance is based upon an assessment of customer creditworthiness, historical payment experience, the age of outstanding receivables, and economic conditions that may affect a customer’s ability to pay. Contract Assets Contract assets include unbilled amounts typically resulting from the Company’s station construction sale contracts, when the cost-to-cost method of revenue recognition is utilized and revenue recognized exceeds the amount billed to the customer, and right to payment is not just subject to the passage of time. Amounts may not exceed their net realizable value. Contract assets are classified as current or noncurrent based on the timing of billings. The current portion is included in “Prepaid expenses and other current assets” and the noncurrent portion is included in “Notes receivable and other long-term assets, net” in the accompanying condensed consolidated balance sheets. Contract Liabilities Contract liabilities consist of billings in excess of revenue recognized from the Company’s station construction sale contracts and payments received primarily from customers of NG Advantage, LLC (“NG Advantage”) in advance of the performance obligations and are classified as current or noncurrent based on when the related revenue is expected to be recognized. The current portion and noncurrent portion of contract liabilities are included in “Deferred revenue” and “Other long-term liabilities,” respectively, in the accompanying condensed consolidated balance sheets. Revenue recognized during the nine months ended September 30, 2021 related to the Company’s contract liability balances as of December 31, 2020 was $1.5 million. The decrease in the contract liability balances during the nine months ended September 30, 2022 is primarily driven by $2.5 million of revenue recognized related to the Company’s contract liability balances as of December 31, 2021, partially offset by billings in excess of revenue recognized.

Investments in Other Entities a

Investments in Other Entities and Noncontrolling Interest in a Subsidiary	9 Months Ended
	Sep. 30, 2022
Investments, All Other Investments [Abstract]
Investments in Other Entities and Noncontrolling Interest in a Subsidiary	Note 3— Investments in Other Entities and Noncontrolling Interest in a Subsidiary TotalEnergies Joint Venture On March 3, 2021, the Company entered an agreement (the “TotalEnergies JV Agreement”) with TotalEnergies S.E. (“TotalEnergies”) that created a 50/50 joint venture (the “TotalEnergies JV”) to develop anaerobic digester gas (“ADG”) RNG production facilities in the United States. Each ADG RNG production facility project under the TotalEnergies JV will be formed as a separate limited liability company (“LLC”) that is owned 50/50 by the Company and TotalEnergies, and contributions to such LLCs count toward the TotalEnergies JV Equity Obligations (as defined below). The TotalEnergies JV Agreement contemplates that the TotalEnergies JV will invest up to $400.0 million of equity in production projects, and TotalEnergies and the Company each committed to initially provide $50.0 million for the TotalEnergies JV (the “TotalEnergies JV Equity Obligations”). On October 12, 2021, TotalEnergies and the Company executed a LLC agreement (the “DR Development Agreement”) for an ADG RNG production facility project (the “DR JV”). Under the DR Development Agreement, TotalEnergies and the Company have each committed to contribute $7.0 million to the DR JV. On November 1, 2021, TotalEnergies and the Company each contributed an initial $4.8 million to the DR JV. The Company accounts for its interest in the LLCs using the equity method of accounting because the Company does not control but has the ability to exercise significant influence over the LLCs’ operations. The Company recorded a loss of $0.0 million and $0.1 million from the TotalEnergies JV for the three and nine months ended September 30, 2022, respectively. The Company had an investment balance in the TotalEnergies JV of $4.7 million and $4.6 million as of December 31, 2021 and September 30, 2022, respectively. bp Joint Venture On April 13, 2021, the Company entered an agreement (the “bp JV Agreement”) with bp Products North America Inc. (“bp”) that created a 50/50 joint venture (the “bpJV”) to develop, own and operate new ADG RNG production facilities in the United States. Pursuant to the bp JV Agreement, bp and the Company committed to provide $50.0 million and $30.0 million, respectively, with bp Pursuant to the bp JV Agreement, the Company had the option, exercisable prior to August 31, 2021 (the “bp Option”), to commit an additional $20.0 million to the bpJV upon which bp’s Class B Units would convert into Class A Units. On June 21, 2021, the Company contributed $50.2 million to the bpJV, which consisted of (i) its initial contribution commitment of $30.0 million, (ii) the $20.0 million additional contribution to effect the conversion of bp’s Class B Units into Class A Units pursuant to the Company’s exercise of the bp Option, and (iii) $0.2 million for interest on bp’s Class B Units to acquire additional Class A Units. In December 2021, the bpJV issued a capital call (the “bpJV Capital Call”) for $143.2 million in additional funding, requiring bp bp Company The Company accounts for its interest in the bpJV using the equity method of accounting because the Company does not control but has the ability to exercise significant influence over the bpJV’s operations. The Company recorded a loss of $0.2 million and $2.2 million from this investment for the three and nine months ended September 30, 2022, respectively. The Company had an investment balance in the bpJV of $69.8 million and $157.3 million as of December 31, 2021 and September 30, 2022, respectively. SAFE&CEC S.r.l. On November 26, 2017, the Company, through its former subsidiary IMW Industries Ltd. (formerly known as Clean Energy Compression Corp.) (“CEC”), entered into an investment agreement with Landi Renzo S.p.A. (“LR”), an alternative fuels company based in Italy. Pursuant to the investment agreement, the Company and LR agreed to combine their respective natural gas compressor fueling systems manufacturing subsidiaries, CEC and SAFE S.p.A, into a new company, SAFE&CEC S.r.l. (such combination transaction is referred to as the “CEC Combination”). SAFE&CEC S.r.l. is focused on manufacturing, selling and servicing natural gas fueling compressors and related equipment for the global natural gas fueling market. As of the closing of the CEC Combination on December 29, 2017, the Company owned 49% of SAFE&CEC S.r.l., and LR owned 51% of SAFE&CEC S.r.l. The Company accounts for its interest in SAFE&CEC S.r.l. using the equity method of accounting because the Company does not control but has the ability to exercise significant influence over SAFE&CEC S.r.l.’s operations. The Company recorded a loss of $0.1 million and $0.3 million from this investment for the three months ended September 30, 2021 and 2022, respectively, and a loss of $0.0 million and $0.6 million for the nine months ended September 30, 2021 and 2022, respectively. The Company had an investment balance in SAFE&CEC S.r.l. of $23.9 million and $20.8 million as of December 31, 2021 and September 30, 2022, respectively. NG Advantage On October 14, 2014, the Company entered into a Common Unit Purchase Agreement (“UPA”) with NG Advantage for a 53.3% controlling interest in NG Advantage. Subsequently, the Company’s controlling interest increased in connection with various equity and financing arrangements with NG Advantage. As of September 30, 2022, the Company’s controlling interest in NG Advantage was 93.3%. NG Advantage is engaged in the business of transporting CNG in high-capacity trailers to industrial and institutional energy users, such as hospitals, food processors, manufacturers and paper mills that do not have direct access to natural gas pipelines. The Company recorded a loss attributable to the noncontrolling interest in NG Advantage of $0.2 million and $0.1 million for the three months ended September 30, 2021 and 2022, respectively, and $0.8 million and $0.6 million for the nine months ended September 30, 2021 and 2022, respectively. The value of the noncontrolling interest was $8.3 million and $7.7 million as of December 31, 2021 and September 30, 2022, respectively. Investments in Equity Securities For investments in equity securities of privately held entities without readily determinable fair values, the Company measures such investments at cost, adjusted for impairment, if any, and observable price changes in orderly transactions for the identical or similar investment of the same issuer. As of September 30, 2022, the Company had an investment balance recorded at cost of $8.0 million. The Company did not recognize any adjustments to the recorded cost basis during the three and nine months ended September 30, 2022.

Cash, Cash Equivalents and Rest

Cash, Cash Equivalents and Restricted Cash	9 Months Ended
	Sep. 30, 2022
Cash and Cash Equivalents [Abstract]
Cash, Cash Equivalents and Restricted Cash	Note 4—Cash, Cash Equivalents and Restricted Cash Cash, cash equivalents and restricted cash as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 ​ 2022 Current assets: ​ ​ Cash and cash equivalents ​ $ 99,448 ​ $ 23,123 Total cash and cash equivalents ​ $ 99,448 ​ $ 23,123 ​ ​ ​ ​ ​ ​ ​ Long-term assets: ​ ​ Restricted cash - held as collateral ​ $ 7,008 ​ $ — Total restricted cash ​ $ 7,008 ​ $ — ​ ​ ​ ​ ​ ​ ​ Total cash, cash equivalents and restricted cash ​ $ 106,456 ​ $ 23,123 ​ The Company considers all highly liquid investments with maturities of three months or less on the date of acquisition to be cash equivalents. The Company places its cash and cash equivalents with high credit quality financial institutions. At times, such balances may be in excess of the Federal Deposit Insurance Corporation (“FDIC”) and Canadian Deposit Insurance Corporation (“CDIC”) limits. Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash deposits. The amounts in excess of FDIC and CDIC limits were approximately $98.0 million and $21.7 million as of December 31, 2021 and September 30, 2022, respectively. The Company classifies restricted cash as short-term and a current asset if the cash is expected to be used in operations within a year or to acquire a current asset. Otherwise, the restricted cash is classified as long-term. In January 2022, in connection with the second amendment to the Berkshire ALA (as defined in Note 12), the lender to NG Advantage released to the Company $7.0 million, classified in “Restricted cash” on the accompanying condensed consolidated balance sheet as of December 31, 2021. The amount represented the collateral deposit for the limited guaranty provided by the Company under the Berkshire ALA. See Note 12 for more information.

Short-Term Investments

Short-Term Investments	9 Months Ended
	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Short-Term Investments	Note 5—Short-Term Investments Short-term investments include available-for-sale debt securities and certificates of deposit. Available-for-sale debt securities are carried at fair value, inclusive of unrealized gains and losses. Unrealized gains and losses on available-for-sale debt securities are recognized in other comprehensive income (loss), net of applicable income taxes. Gains or losses on sales of available-for-sale debt securities are recognized on the specific identification basis. The Company reviews available-for-sale debt securities for declines in fair value below their cost basis each quarter and whenever events or changes in circumstances indicate that the cost basis of an asset may not be recoverable, and evaluates the current expected credit loss. This evaluation is based on a number of factors, including historical experience, market data, issuer-specific factors, economic conditions, and any changes to the credit rating of the security. As of September 30, 2022, the Company has not recorded a credit loss related to available-for-sale debt securities and believes the carrying values for its available-for-sale debt securities are properly recorded. Short-term investments as of December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Estimated ​ Cost Gain (Loss) Fair Value Municipal bonds and notes ​ $ 6,001 ​ $ (1) ​ $ 6,000 Zero coupon bonds ​ 123,210 ​ (18) ​ 123,192 Certificates of deposit ​ 530 ​ — ​ 530 Total short-term investments ​ $ 129,741 ​ $ (19) ​ $ 129,722 ​ Short-term investments as of September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Estimated ​ Cost Gain (Loss) Fair Value Zero coupon bonds ​ $ 111,154 ​ $ (695) ​ $ 110,459 Certificates of deposit ​ ​ 530 ​ ​ — ​ ​ 530 Total short-term investments ​ $ 111,684 ​ $ (695) ​ $ 110,989 ​

Derivative Instruments and Hedg

Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivative Instruments and Hedging Activities	Note 6—Derivative Instruments and Hedging Activities In October 2018, the Company executed two commodity swap contracts with TotalEnergies Gas & Power North America, an affiliate of TotalEnergies and THUSA (as defined in Note 12), for a total of 5.0 million diesel gallons annually from April 1, 2019 to June 30, 2024. These commodity swap contracts are used to manage diesel price fluctuation risks related to the natural gas fuel supply commitments the Company makes in its fueling agreements with fleet operators that participate in the Zero Now The Company has entered into fueling agreements with fleet operators under the Zero Now Derivatives and embedded derivatives as of December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Amounts ​ Gross Amounts ​ Net Amount ​ Recognized Offset Presented Assets: ​ ​ ​ Fueling agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ Prepaid expenses and other current assets ​ $ 2,038 ​ $ — ​ $ 2,038 Notes receivable and other long-term assets, net ​ ​ 4,738 ​ ​ — ​ ​ 4,738 Total derivative assets ​ $ 6,776 ​ $ — ​ $ 6,776 Liabilities: ​ ​ ​ Commodity swaps: ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of derivative liabilities, related party ​ $ 1,900 ​ $ — ​ $ 1,900 Long-term portion of derivative liabilities, related party ​ 2,483 ​ — ​ 2,483 Total derivative liabilities ​ $ 4,383 ​ $ — ​ $ 4,383 ​ Derivatives and embedded derivatives as of September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Amounts ​ Gross Amounts ​ Net Amount ​ Recognized Offset Presented Assets: ​ ​ ​ Fueling agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ Prepaid expenses and other current assets ​ $ 2,619 ​ $ — ​ $ 2,619 Notes receivable and other long-term assets, net ​ ​ 3,827 ​ ​ — ​ ​ 3,827 Total derivative assets ​ $ 6,446 ​ $ — ​ $ 6,446 Liabilities: ​ ​ ​ Commodity swaps: ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of derivative liabilities, related party ​ $ 3,912 ​ $ — ​ $ 3,912 Long-term portion of derivative liabilities, related party ​ ​ 1,694 ​ ​ — ​ ​ 1,694 Fueling agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ Accrued liabilities ​ ​ 14 ​ ​ — ​ ​ 14 Other long-term liabilities ​ ​ 39 ​ ​ — ​ ​ 39 Total derivative liabilities ​ $ 5,659 ​ $ — ​ $ 5,659 ​ As of December 31, 2021 and September 30, 2022, the Company had a total volume on open commodity swap contracts of 11.9 million and 8.1 million diesel gallons, respectively, at a weighted-average price of approximately $3.22 per gallon. The following table reflects the weighted-average price of open commodity swap contracts as of December 31, 2021 and September 30, 2022, by year with associated volumes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ September 30, 2022 ​ ​ Volumes ​ Weighted-Average Price per ​ Volumes ​ Weighted-Average Price per Year (Diesel Gallons) Diesel Gallon (Diesel Gallons) Diesel Gallon 2022 5,000,000 ​ $ 3.18 1,250,000 ​ $ 3.22 2023 5,000,000 ​ $ 3.18 5,000,000 ​ $ 3.22 2024 1,875,000 ​ $ 3.18 1,875,000 ​ $ 3.22 ​

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Fair Value Measurements	Note 7—Fair Value Measurements The Company follows the authoritative guidance for fair value measurements with respect to assets and liabilities that are measured at fair value on a recurring basis and non-recurring basis. Under the standard, fair value is defined as the exit price, or the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants, as of the measurement date. The standard also establishes a hierarchy for inputs used in measuring fair value that maximizes the use of observable inputs and minimizes the use of unobservable inputs by requiring that the most observable inputs be used when available. Observable inputs are inputs market participants would use in valuing the asset or liability developed based on market data obtained from sources independent of the Company. Unobservable inputs are inputs that reflect the Company’s assumptions about the factors market participants would use in valuing the asset or liability developed based upon the best information available in the circumstances. The hierarchy consists of the following three levels: Level 1 inputs are quoted prices (unadjusted) in active markets for identical assets or liabilities; Level 2 inputs include quoted prices for similar assets or liabilities in active markets, quoted prices for identical or similar assets or liabilities in markets that are not active, and inputs (other than quoted prices) that are observable for the asset or liability, either directly or indirectly; and Level 3 inputs are unobservable inputs for the asset or liability. Categorization within the valuation hierarchy is based upon the lowest level of input that is significant to the fair value measurement. Assets and Liabilities Measured at Fair Value on a Recurring Basis The Company’s available-for-sale debt securities and certificates of deposit are classified within Level 2 because they are valued using the most recent quoted prices for identical assets in markets that are not active and quoted prices for similar assets in active markets. The Company used the income approach to value its outstanding commodity swap contracts and embedded derivatives in its fueling agreements under the Zero Now The Company estimated the fair value of its outstanding commodity swap contracts based on the following inputs as of December 31, 2021 and September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ September 30, 2022 Significant Unobservable Inputs Input Range Weighted Average Input Range Weighted Average ULSD Gulf Coast Forward Curve ​ $2.03 - $2.15 ​ $ 2.11 ​ $ 2.19 - $ 2.58 ​ $ 2.38 Historical Differential to PADD 3 Diesel ​ $0.87 - $1.58 ​ $ 1.03 ​ $ 0.87 - $ 1.60 ​ $ 1.10 Historical Differential to PADD 5 Diesel ​ $1.82 - $2.69 ​ $ 2.13 ​ $ 1.91 - $ 3.05 ​ $ 2.26 ​ The Company estimated the fair value of embedded derivatives in its fueling agreements under the Zero Now ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ September 30, 2022 Significant Unobservable Inputs Input Range Weighted Average Input Range Weighted Average ULSD Gulf Coast Forward Curve ​ $2.03 - $2.15 ​ $ 2.11 ​ $ 2.19 - $ 2.58 ​ $ 2.38 Historical Differential to PADD 3 Diesel ​ $0.87 - $1.58 ​ $ 1.03 ​ $ 0.87 - $ 1.60 ​ $ 1.10 Historical Differential to PADD 5 Diesel ​ $1.82 - $2.69 ​ $ 2.13 ​ $ 1.91 - $ 3.05 ​ $ 2.26 ​ There were no transfers of assets or liabilities between Level 1, Level 2, or Level 3 of the fair value hierarchy as of December 31, 2021 or September 30, 2022. The following tables provide information by level for assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2021 and September 30, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 Level 1 Level 2 Level 3 Assets: ​ ​ ​ ​ Available-for-sale securities (1) ​ ​ ​ ​ Municipal bonds and notes ​ $ 6,000 ​ $ — ​ $ 6,000 ​ $ — Zero coupon bonds ​ 123,192 ​ — ​ 123,192 ​ — Certificates of deposit (1) ​ 530 ​ — ​ 530 ​ — Embedded derivatives (3) ​ ​ 6,776 ​ ​ — ​ ​ — ​ ​ 6,776 Liabilities: ​ ​ ​ ​ ​ Commodity swap contracts (2) ​ $ 4,383 ​ $ — ​ $ — ​ $ 4,383 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 Level 1 Level 2 Level 3 Assets: ​ ​ ​ Available-for-sale securities (1) ​ ​ ​ ​ Zero coupon bonds ​ $ 110,459 ​ $ — ​ $ 110,459 ​ $ — Certificates of deposit (1) ​ ​ 530 ​ ​ — ​ ​ 530 ​ ​ — Embedded derivatives (3) ​ ​ 6,446 ​ ​ — ​ ​ — ​ ​ 6,446 Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity swap contracts (2) ​ $ 5,606 ​ $ — ​ $ — ​ $ 5,606 Embedded derivatives (3) ​ ​ 53 ​ ​ — ​ ​ — ​ ​ 53 ​ (1) Included in "Short-term investments" in the accompanying condensed consolidated balance sheets. See Note 5 for more information. (2) Included in "Derivative liabilities, related party" and "Long-term portion of derivative liabilities, related party" as of December 31, 2021 and September 30, 2022 in the accompanying condensed consolidated balance sheets. See Note 6 for more information. (3) Included in "Prepaid expenses and other current assets" and “Notes receivable and other long-term assets, net" as of December 31, 2021, and in "Prepaid expenses and other current assets," “Notes receivable and other long-term assets, net," “Accrued liabilities” and “Other long-term liabilities” as of September 30, 2022 in the accompanying condensed consolidated balance sheets. See Note 6 for more information. The following tables provide a reconciliation of the beginning and ending balances of items measured at fair value on a recurring basis as shown in the tables above that used significant unobservable inputs (Level 3), as well as the change in unrealized gains or losses for the periods included in earnings (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets: ​ Assets: ​ Liabilities: ​ Liabilities: ​ ​ Commodity ​ Embedded ​ Commodity ​ Embedded ​ Swap Contracts Derivatives ​ Swap Contracts ​ Derivatives Balance as of June 30, 2021 ​ $ — ​ $ 5,069 ​ $ (1,693) ​ $ — Settlements, net ​ ​ — ​ ​ — ​ ​ 265 ​ ​ — Total gain (loss) ​ 587 ​ (1,926) ​ 1,428 ​ (87) Balance as of September 30, 2021 ​ $ 587 ​ $ 3,143 ​ $ — ​ $ (87) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of June 30, 2022 ​ $ — ​ $ 11,345 ​ $ (11,034) ​ $ (32) Settlements, net ​ ​ — ​ ​ — ​ ​ 1,942 ​ ​ — Total gain (loss) ​ — ​ ​ (4,899) ​ ​ 3,486 ​ ​ (21) Balance as of September 30, 2022 ​ $ — ​ $ 6,446 ​ $ (5,606) ​ $ (53) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in unrealized gain (loss) for the three months ended September 30, 2021 included in earnings ​ $ 587 ​ $ (1,926) ​ $ 1,693 ​ $ (87) Change in unrealized gain (loss) for the three months ended September 30, 2022 included in earnings ​ $ — ​ $ (4,899) ​ $ 5,428 ​ $ (21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets: ​ Assets: ​ Liabilities: ​ Liabilities: ​ ​ Commodity ​ Embedded ​ Commodity ​ Embedded ​ Swap Contracts Derivatives ​ Swap Contracts ​ Derivatives Balance as of December 31, 2020 ​ $ 5,648 ​ $ 791 ​ $ — ​ $ (556) Settlements, net ​ ​ (225) ​ ​ — ​ ​ 614 ​ ​ — Total gain (loss) ​ (4,836) ​ ​ 2,352 ​ ​ (614) ​ ​ 469 Balance as of September 30, 2021 ​ $ 587 ​ $ 3,143 ​ $ — ​ $ (87) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2021 ​ $ — ​ $ 6,776 ​ $ (4,383) ​ $ — Settlements, net ​ ​ — ​ ​ — ​ ​ 5,843 ​ ​ — Total gain (loss) ​ — ​ ​ (330) ​ ​ (7,066) ​ ​ (53) Balance as of September 30, 2022 ​ $ — ​ $ 6,446 ​ $ (5,606) ​ $ (53) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in unrealized gain (loss) for the nine months ended September 30, 2021 included in earnings ​ $ (5,061) ​ $ 2,352 ​ $ — ​ $ 469 Change in unrealized gain (loss) for the nine months ended September 30, 2022 included in earnings ​ $ — ​ $ (330) ​ $ (1,223) ​ $ (53) ​ Other Financial Assets and Liabilities The carrying amounts of the Company’s cash, cash equivalents, receivables and payables approximate fair value due to the short-term nature of those instruments. The carrying amounts of the Company’s debt instruments approximated their respective fair values as of December 31, 2021 and September 30, 2022. The fair values of these debt instruments were estimated using a discounted cash flow analysis based on interest rates offered on loans with similar terms to borrowers of similar credit quality, which are Level 3 inputs. See Note 12 for more information about the Company’s debt instruments.

Other Receivables

Other Receivables	9 Months Ended
	Sep. 30, 2022
Receivables [Abstract]
Other Receivables	Note 8—Other Receivables Other receivables as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 2022 Loans to customers to finance vehicle purchases ​ $ 419 ​ $ 512 Accrued customer billings ​ 4,417 ​ 3,946 Fuel tax credits ​ 12,684 ​ 27,402 Other ​ 6,927 ​ 3,252 Total other receivables ​ $ 24,447 ​ $ 35,112 ​

Inventory

Inventory	9 Months Ended
	Sep. 30, 2022
Inventory Disclosure [Abstract]
Inventory	Note 9—Inventory Inventory consists of raw materials and spare parts, work in process and finished goods and is stated at the lower of cost (first-in, first-out) or net realizable value. The Company evaluates inventory balances for excess quantities and obsolescence by analyzing estimated demand, inventory on hand, sales levels and other information, and reduces inventory balances to net realizable value for excess and obsolete inventory based on this analysis. Inventory as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 ​ 2022 Raw materials and spare parts ​ $ 31,302 ​ $ 35,927 Total inventory ​ $ 31,302 ​ $ 35,927 ​

Land, Property and Equipment

Land, Property and Equipment	9 Months Ended
	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Land, Property and Equipment	Note 10—Land, Property and Equipment Land, property and equipment, net as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ 2021 2022 Land ​ $ 3,476 ​ $ 3,476 LNG liquefaction plants ​ 94,633 ​ 94,633 Station equipment ​ 354,699 ​ 353,132 Trailers ​ 72,783 ​ 73,117 Other equipment ​ 93,135 ​ 95,799 Construction in progress ​ 74,963 ​ 76,660 ​ ​ 693,689 ​ 696,817 Less accumulated depreciation ​ (431,928) ​ (447,915) Total land, property and equipment, net ​ $ 261,761 ​ $ 248,902 ​ Included in "Land, property and equipment, net" are capitalized software costs of $33.8 million and $35.0 million as of December 31, 2021 and September 30, 2022, respectively. Accumulated amortization of the capitalized software costs are $30.4 million and $31.7 million as of December 31, 2021 and September 30, 2022, respectively. The Company recorded amortization expense related to capitalized software costs of $0.3 million and $0.7 million for the three months ended September 30, 2021 and 2022, respectively, and $1.2 million and $1.3 million for the nine months ended September 30, 2021 and 2022, respectively. As of December 31, 2021 and September 30, 2022, $2.1 million and $2.9 million, respectively, are included in "Accounts payable" and "Accrued liabilities" in the accompanying condensed consolidated balance sheet, representing amounts related to purchases of property and equipment. These amounts are excluded from the accompanying condensed consolidated statements of cash flows as they are non-cash investing activities. ​ Fueling Station Equipment Removal The Company was requested by Pilot Travel Centers LLC (“Pilot”) to remove station equipment at select Pilot locations to accommodate Pilot making physical changes to the premises, which required the removal of the Company’s station equipment. The premises, where the affected fueling stations are located, were secured by long-term lease agreements between Pilot and the Company pursuant to which the Company had contractual rights to operate its fueling stations until the expiration of the respective leases. However, in July 2022, the Company entered into an amendment (the “Amendment”) to the Liquefied Natural Gas Fueling Station and LNG Master Sales Agreement between Pilot and Clean Energy, dated August 2, 2010, to decommission and remove station equipment from the premises where the affected fueling stations are located in accordance with a phased removal schedule. The Amendment requires the Company to remove station equipment and site improvements from the premises beginning in the third quarter of 2022 and to complete removal by the end of the first quarter of 2023. In connection with the removal of station equipment and site improvements, the Company recognized $8.1 million in accelerated depreciation expense relating to the change in depreciable life of the affected station assets and $0.7 million in incremental asset retirement obligation (“ARO”) charges. Amounts associated with the accelerated depreciation expense and incremental ARO charges are included in “Depreciation and amortization” in the accompanying condensed consolidated statements of operations for the three and nine months ended September 30, 2022.

Accrued Liabilities

Accrued Liabilities	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
Accrued Liabilities	Note 11—Accrued Liabilities Accrued liabilities as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ September 30, ​ 2021 2022 Accrued alternative fuels incentives (1) ​ $ 28,106 ​ $ 30,948 Accrued employee benefits ​ 4,547 ​ 4,476 Accrued gas and equipment purchases ​ 17,158 ​ 22,532 Accrued interest ​ 893 ​ 1,685 Accrued property and other taxes ​ 3,369 ​ 4,075 Accrued salaries and wages ​ 8,172 ​ 6,687 Embedded derivatives ​ ​ — ​ ​ 14 Other (2) ​ 12,914 ​ 14,783 Total accrued liabilities ​ $ 75,159 ​ $ 85,200 (1) Includes amount for RINs, LCFS Credits, and AFTC payable to third parties. (2) No individual item in “Other” exceeds 5% of total current liabilities .

Debt

Debt	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Debt	Note 12—Debt Debt obligations as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ Unamortized Debt Balance, Net of ​ ​ Principal Balance ​ Financing Costs ​ Financing Costs NG Advantage debt ​ $ 25,832 $ 72 ​ $ 25,760 SG Facility ​ ​ 9,500 ​ ​ — ​ ​ 9,500 Other debt ​ 800 ​ — ​ 800 Total debt ​ 36,132 ​ 72 ​ 36,060 Less amounts due within one year ​ (12,868) ​ (23) ​ (12,845) Total long-term debt ​ $ 23,264 ​ $ 49 ​ $ 23,215 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ ​ Unamortized Debt Balance, Net of ​ ​ Principal Balance ​ Financing Costs ​ Financing Costs NG Advantage debt ​ $ 26,515 ​ $ 108 ​ $ 26,407 SG Facility ​ ​ 2,000 ​ ​ — ​ ​ 2,000 Other debt ​ 148 ​ ​ — ​ ​ 148 Total debt ​ 28,663 ​ 108 ​ 28,555 Less amounts due within one year ​ (4,198) ​ ​ (33) ​ ​ (4,165) Total long-term debt ​ $ 24,465 ​ $ 75 ​ $ 24,390 ​ SG Credit Agreement On January 2, 2019, the Company entered into a term credit agreement (the “Credit Agreement”) with Société Générale, a company incorporated as a société anonyme under the laws of France (“SG”). The Credit Agreement provides for a term loan facility (the “SG Facility”) pursuant to which the Company may obtain, subject to certain conditions, up to $100.0 million of loans (“SG Loans”) in support of its Zero Now Zero Now The Company is required to make quarterly principal payments of $2.5 million beginning March 31, 2022 with any unpaid amount due on January 2, 2024, subject to the option to extend the maturity date for three successive terms of one year each. The Company is required to make mandatory prepayments under the SG Facility equal to any amounts the Company receives for complete or partial refunds of the incremental cost of trucks purchased or financed under the Zero Now The Credit Agreement does not include financial covenants, and the Company has not provided SG with any security for its obligations under the Credit Agreement. As described below, THUSA has entered into the Guaranty to guarantee the Company’s payment obligations to SG under the Credit Agreement. As of September 30, 2022, the Company had $2.0 million outstanding on the SG Facility, and no events of defaults had occurred. TotalEnergies Credit Support Agreement The Company entered into a credit support agreement with TotalEnergies Holdings USA Inc. (“THUSA”), a wholly owned subsidiary of TotalEnergies, on January 2, 2019, which was subsequently amended on March 12, 2021 (as amended, the “CSA”) in conjunction with the March 12, 2021 amendment to the Credit Agreement. Under the CSA, THUSA agreed to enter into a guaranty agreement (“Guaranty”) pursuant to which it has guaranteed the Company’s obligation to repay to SG up to $100.0 million in SG Loans and interest thereon in accordance with the Credit Agreement. In consideration for the commitments of THUSA under the CSA, the Company is required to pay THUSA a quarterly guaranty fee at a rate per quarter equal to 2.5% of the average aggregate SG Loan amount for the preceding calendar quarter. Following any payment by THUSA to SG under the Guaranty, the Company would be obligated to immediately pay to THUSA the full amount of such payment plus interest on such amount at a rate equal to LIBOR plus 1.0%. In addition, the Company would be obligated to pay and reimburse THUSA for all reasonable out-of-pocket expenses it incurs in the performance of its services under the CSA, including all reasonable out-of-pocket attorneys’ fees and expenses incurred in connection with the payment to SG under the Guaranty or any enforcement or attempt to enforce any of the Company‘s obligations under the CSA. The CSA includes customary representations and warranties and affirmative and negative covenants by the Company. In addition, upon the occurrence of a Trigger Event (as described below) and during its continuation, THUSA may, among other things: elect not to guarantee additional SG Loans; declare all or any portion of the outstanding amounts the Company owes THUSA under the CSA to be due and payable; and exercise all other rights it may have under applicable law. Each of the following events constitutes a Trigger Event: the Company defaults with respect to any payment obligation under the CSA; any representation or warranty made by the Company in the CSA was false, incorrect, incomplete or misleading in any material respect when made; the Company fails to observe or perform any material covenant, obligation, condition or agreement in the CSA; or the Company defaults in the observance or performance of any agreement, term or condition contained in any other agreement with THUSA or an affiliate of THUSA. As security for the Company’s obligations under the CSA, on January 2, 2019, the Company entered into a pledge and security agreement with THUSA and delivered a collateral assignment of contracts to THUSA, pursuant to which the Company collaterally assigned to THUSA all fueling agreements it enters into with participants in the Zero Now Zero Now Until the occurrence of a Trigger Event or Fundamental Trigger Event (as described below) under the CSA, the Company has the freedom to operate in the normal course, and there are no restrictions on the flow of funds in and out of the lockbox account established pursuant to the lockbox agreement. Upon the occurrence of a Trigger Event under the CSA, all funds in the lockbox account will be: first, used to make scheduled debt repayments under the Credit Agreement; and second, released to the Company. Further, upon the occurrence of a “Fundamental Trigger Event” under the CSA and during its continuation, in addition to exercising any of the remedies available to THUSA upon the occurrence of a Trigger Event as described above: all participants in the Zero Now cause, acceleration of indebtedness in an aggregate amount for all such collective defaults of $20.0 million or more; voluntary and involuntary bankruptcy and insolvency events; and the occurrence of a change of control of the Company. The CSA will terminate following the later of: the payment in full of all of the Company’s obligations under the CSA; and the termination or expiration of the Guaranty following the maturity date of the last outstanding SG Loan or December 31, 2023, whichever is earlier. NG Advantage Debt On November 30, 2016, NG Advantage entered into a Loan and Security Agreement (the “Wintrust LSA”) with Wintrust Commercial Finance (“Wintrust”), pursuant to which Wintrust agreed to lend NG Advantage $4.7 million. The proceeds were primarily used to fund the purchases of CNG trailers and equipment. Interest and principal are payable monthly in 72 equal monthly installments at an annual rate of 5.17%. As collateral security for the prompt payment in full when due of NG Advantage’s obligations to Wintrust under the Wintrust LSA, NG Advantage pledged to and granted Wintrust a security interest in all of its right, title and interest in the CNG trailers and equipment purchased with the proceeds received under the Wintrust LSA. As of September 30, 2022, NG Advantage had $0.1 million outstanding under the Wintrust LSA. On December 10, 2020, NG Advantage entered an Amended and Restated Loan and Security Agreement with Berkshire Bank (the “Berkshire ALA”) to substitute and replace the two existing loans with Berkshire Bank dated May 12, 2016 and January 24, 2017 (collectively, the “Original Debt”). The Berkshire ALA provides NG Advantage a 5-year On January 31, 2022, NG Advantage entered into a second amendment to the Berkshire ALA pursuant to which Berkshire Bank agreed to extend additional new term loans with an aggregate principal amount of $14.0 million (collectively, the “Berkshire Term Loan 2”) to NG Advantage. The Berkshire Term Loan 2 bears interest at an annual interest rate of 5% and has a maturity date of January 31, 2027. Payments for interest and principal are due monthly beginning March 1, 2022, with a final payment of remaining principal and interest due on the maturity date. Borrowings under the Berkshire Term Loan 2 are collateralized by various trailers and station assets of NG Advantage, and prepayment of the outstanding principal is permitted and subject to prepayment premiums. Financial and non-financial covenants of the Berkshire Term Loan 2 are identical to those under the Berkshire ALA. NG Advantage used the proceeds from the Berkshire Term Loan 2 to repay in full the outstanding balances of certain other financing obligations to unrelated lenders. As a result of the full repayment of NG Advantage’s financing obligations to unrelated lenders, for the nine months ended September 30, 2022, the Company recognized a $2.3 In connection with the second amendment to the Berkshire ALA, Berkshire Bank released $7.0 million, classified in “Restricted cash” on the accompanying condensed consolidated balance sheets as of December 31, 2021, to the Company related to the Company’s limited guaranty under the Berkshire ALA. Concurrently, the Company issued a $7.0 million irrevocable standby letter of credit to Berkshire Bank as collateral under the second amendment to the Berkshire ALA. The standby letter of credit is valid until specified release conditions are satisfied and is collateralized by the Plains LSA (as defined below). The amended Berkshire ALA also provides NG Advantage a $1.0 million revolving line of credit which bears interest at the greater of the Prime Rate or 3.00%, plus 0.25% and has a maturity date of July 31, 2023. As of September 30, 2022, NG Advantage had no amounts outstanding on the revolving line of credit. ​ Financing Obligations NG Advantage has entered into sale and leaseback transactions with various lessors as described below. In each instance, the sale and leaseback transaction does not qualify for sale-leaseback accounting because of NG Advantage’s continuing involvement with the buyer-lessor due to a fixed price repurchase option. As a result, the transactions are recorded under the financing method, in which the assets remain on the accompanying condensed consolidated balance sheets and the proceeds from the transactions are recorded as financing liabilities. On December 18, 2017, NG Advantage entered into a sale-leaseback arrangement through a Master Lease Agreement (the “BoA MLA”) with Bank of America Leasing & Capital, LLC (“BoA”). Pursuant to the BoA MLA, NG Advantage received $2.1 million in cash for CNG trailers and simultaneously leased them back from BoA for five years commencing January 1, 2018 with interest and principal payable in 60 equal monthly installments at an annual rate of 4.86%. As of September 30, 2022, NG Advantage had $0.1 million outstanding under the BoA MLA. On March 1, 2018, NG Advantage entered into a sale-leaseback arrangement through a Master Lease Agreement (the “First National MLA”) with First National Capital, LLC (“First National”). Pursuant to the First National MLA, NG Advantage received $6.3 million in cash, net of fees and the first month’s lease payment for CNG trailers and simultaneously leased CNG trailers back from First National for six years commencing March 1, 2018 with interest and principal payable in 72 equal monthly installments at an annual rate of 9.28%. On January 31, 2022, NG Advantage used proceeds from the Berkshire Term Loan 2 and $0.8 million in deposits held with First National to repay in full the remaining outstanding financing obligations under the First National MLA. The application of $0.8 million in deposits to extinguish financing obligations under the First National MLA was excluded from the accompanying condensed consolidated statements of cash flows as it was a non-cash financing activity. As of September 30, 2022, no amounts were outstanding under the First National MLA. On December 20, 2018 (the “Closing Date”), NG Advantage entered into a purchase agreement to sell a compression station for $7.0 million to an entity the member owners of which were noncontrolling interest member owners of NG Advantage. On the Closing Date and immediately following the consummation of the sale of the compression station, NG Advantage entered into a lease agreement with the buyer of the station pursuant to which the station was leased back to NG Advantage for a term of five years with monthly rent payments equal to $0.1 million at an annual rate of 12.0%. On January 31, 2022, NG Advantage used proceeds from the Berkshire Term Loan 2 to repay in full the remaining outstanding financing obligations related to the lease agreement for the compression station. As of September 30, 2022, no amounts were outstanding. Plains Credit Facility On May 1, 2021, the Company entered into a Loan and Security Agreement (the “Plains LSA”) with PlainsCapital Bank (“Plains”), which provides the Company a $20.0 million revolving line of credit through May 1, 2022. In May 2022, the Plains LSA was renewed and extended through May 1, 2023. The interest rate on amounts outstanding under the Plains LSA is the greater of the Prime Rate or 3.25%. As of September 30, 2022, no amounts were outstanding under the Plains LSA, and the Company was in compliance with the covenants under the Plains LSA. On September 16, 2021, Plains issued an irrevocable standby letter of credit on behalf of the Company to the Chevron Products Company, a division of Chevron U.S.A. Inc. (“Chevron”), for $2.0 million relating to the Company’s Adopt-A-Port program with Chevron. The standby letter of credit is valid until cancelled and is collateralized by the Plains LSA, reducing the amount available under the Plains LSA from $20.0 million to $18.0 million. On January 31, 2022, the Company issued an irrevocable standby letter of credit to Berkshire Bank for $7.0 million as collateral under the second amendment to the Berkshire ALA. The standby letter of credit is collateralized by the Plains LSA, reducing the amount available under the Plains LSA to $11.0 million. As of September 30, 2022, no amounts have been drawn under the standby letters of credit. Other Debt The Company has other debt due at various dates through 2024 bearing interest at rates up to 4.75% with a weighted-average interest rate of 4.34% and 4.75% as of December 31, 2021 and September 30, 2022, respectively.

Net Income (Loss) Per Share

Net Income (Loss) Per Share	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Net Income (Loss) Per Share	Note 13—Net Income (Loss) Per Share Basic net income (loss) per share is computed by dividing the net income (loss) attributable to Clean Energy Fuels Corp. by the weighted-average number of common shares outstanding and common shares issuable for little or no cash consideration during the period. Diluted net income (loss) per share is computed by dividing the net income (loss) attributable to Clean Energy Fuels Corp. by the weighted-average number of common shares outstanding and common shares issuable for little or no cash consideration during the period and potentially dilutive securities outstanding during the period, and therefore reflects the dilution from common shares that may be issued upon exercise or conversion of these potentially dilutive securities, such as stock options, warrants, convertible notes and restricted stock units. The dilutive effect of stock awards and warrants is computed under the treasury stock method. The dilutive effect of convertible notes and restricted stock units is computed under the if-converted method. Potentially dilutive securities are excluded from the computations of diluted net income (loss) per share if their effect would be antidilutive. The following table sets forth the computations of basic and diluted earnings (loss) per share for the three and nine months ended September 30, 2021 and 2022 (in thousands except share and per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ September 30, ​ September 30, ​ ​ 2021 2022 2021 2022 Net loss attributable to Clean Energy Fuels Corp. ​ $ (3,934) ​ $ (8,973) ​ $ (90,770) ​ $ (46,399) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average common shares outstanding ​ 223,008,202 ​ 222,239,376 ​ 209,771,584 ​ 222,409,802 Dilutive effect of potential common shares from restricted stock units, stock options and stock warrants ​ — ​ — ​ — ​ — Weighted-average common shares outstanding - diluted ​ 223,008,202 ​ 222,239,376 ​ 209,771,584 ​ 222,409,802 Basic and diluted loss per share ​ $ (0.02) ​ $ (0.04) ​ $ (0.43) ​ $ (0.21) ​ The following potentially dilutive securities have been excluded from the diluted net loss per share calculations because their effect would have been antidilutive. Although these securities were antidilutive for these periods, they could be dilutive in future periods. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2021 2022 2021 2022 Stock options ​ 8,896,688 ​ ​ 16,170,384 ​ ​ 8,896,688 ​ ​ 16,170,384 Restricted stock units ​ 1,241,306 ​ ​ 680,191 ​ ​ 1,241,306 ​ ​ 680,191 Amazon warrant shares ​ ​ 58,767,714 ​ ​ 58,767,714 ​ ​ 58,767,714 ​ ​ 58,767,714 Total ​ ​ 68,905,708 ​ ​ 75,618,289 ​ ​ 68,905,708 ​ ​ 75,618,289 ​

Stock-Based Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2022
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Note 14—Stock-Based Compensation The following table summarizes the compensation expense and related income tax benefit related to the Company’s stock-based compensation arrangements recognized in the accompanying condensed consolidated statements of operations during the three and nine months ended September 30, 2021 and 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2021 2022 2021 2022 Stock-based compensation expense, net of $0 tax in 2021 and 2022 ​ $ 3,435 ​ $ 5,964 ​ $ 10,220 ​ $ 20,685 ​ As of September 30, 2022, there was $30.9 million of total unrecognized compensation costs related to unvested shares subject to outstanding service-based and market-based stock options and service-based restricted stock units. Unrecognized compensation costs associated with these stock-based awards are expected to be expensed over a weighted-average period of approximately 1.5 years. As of September 30, 2022, total unrecognized compensation costs related to unvested shares subject to outstanding performance-based stock options were $4.7 million. Amazon Warrant On April 16, 2021, the Company entered into a Project Addendum to Fuel Pricing Agreement (the “Fuel Agreement”) with Amazon Logistics, Inc., a subsidiary of Amazon.com, Inc. (“Amazon”), and a Transaction Agreement with Amazon (the “Transaction Agreement”), pursuant to which, among other things, the Company issued to Amazon.com NV Investment Holdings LLC, a subsidiary of Amazon (“Amazon Holdings”), a warrant to purchase up to an aggregate of 53,141,755 shares (the “Warrant Shares”) of the Company’s common stock at an exercise price of $13.49 per share. As a result of the issuance of additional shares of common stock under the Company’s at-the-market offering programs in 2021 and in accordance with the terms of the warrant, on June 14, 2021, the number of shares of the Company’s common stock that may be purchased pursuant to the warrant, at an exercise price of $13.49 per share, increased by an aggregate of 5,625,959 shares (the “Additional Warrant Shares”). The Warrant Shares and the Additional Warrant Shares shall vest in multiple tranches, certain of which vested immediately upon execution of the Fuel Agreement. Subsequent tranches will vest over time based on fuel purchases by Amazon and its affiliates, up to a total of $500.0 million, excluding any payments attributable to “Pass Through Costs,” which consist of all costs associated with the delivered cost of gas and applicable taxes determined by reference to the selling price of gallons or gas sold. The right to exercise the warrants and to receive the Warrant Shares and Additional Warrant Shares (the “Amazon Warrant”) that have vested expires on April 16, 2031. Non-cash stock-based sales incentive contra-revenue charges (“Amazon Warrant Charges”) associated with the Amazon Warrant are recognized as Amazon and its affiliates purchase fuel and vesting conditions become probable of being achieved, based on the grant date fair value of the Amazon Warrant. The following table summarizes the Amazon Warrant activity for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ Warrant ​ Shares Outstanding and unvested as of December 31, 2021 44,077,779 Granted — Vested (1,175,408) Outstanding and unvested as of September 30, 2022 42,902,371 ​ 1,175,408 shares of the Amazon Warrant vested during the nine months ended September 30, 2022 based on fuel purchases made by Amazon and its affiliates. 587,704 shares of the Amazon Warrant vested during the three months ended September 30, 2022. The Company recognized Amazon Warrant Charges of $2.2 million and $7.0 million during the three months ended September 30, 2021 and 2022, respectively, and $80.2 million and $15.5 million during the nine months ended September 30, 2021 and 2022, respectively. Amazon Warrant Charges recognized during the nine months ended September 30, 2021 included $76.6 million from the immediate vesting of a portion of the Amazon Warrant and $3.6 million from customer fuel purchases. Amazon Warrant Charges for the nine months ended September 30, 2022 and for the three months ended September 30, 2021 and 2022 were related to customer fuel purchases. As of September 30, 2022, the Company had a customer incentive asset of $26.7 million classified in “Prepaid expenses and other current assets” in the accompanying condensed consolidated balance sheets.

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2022
Equity [Abstract]
Stockholders' Equity	Note 15—Stockholders’ Equity Authorized Shares Share Repurchase Program On March 12, 2020, the Company’s Board of Directors approved a share repurchase program of up to $30.0 million (exclusive of fees and commissions) of the Company’s outstanding common stock (the “Repurchase Program”). On December 7, 2021, the Company’s Board of Directors approved an increase in the aggregate purchase amount under the Repurchase Program from $30.0 million to $50.0 million (exclusive of fees and commissions). The Repurchase Program does not have an expiration date, and it may be suspended or discontinued at any time. For the nine months ended September 30, 2022, the Company repurchased 1,190,254 shares of its common stock under the Repurchase Program for a total cost of $6.1 million (exclusive of fees and commissions). As of September 30, 2022, the Company had utilized a total of $23.5 million under the Repurchase Program from its inception to repurchase 9,387,340 shares of common stock and had a total of $26.5 million of authorized funds remaining under the Repurchase Program. The Repurchase Program does not obligate the Company to acquire any specific number of shares. Repurchases under the Repurchase Program may be effected from time to time through open market purchases, privately negotiated transactions, structured or derivative transactions, including accelerated share repurchase transactions, or other methods of acquiring shares, in each case subject to market conditions, applicable securities laws and other relevant factors. Repurchases may also be made under plans complying with Rule 10b5-1 under the Securities Exchange Act of 1934, as amended.

Income Taxes

Income Taxes	9 Months Ended
	Sep. 30, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Note 16—Income Taxes The provision for income taxes for interim periods is determined using an estimate of the Company’s annual effective tax rate, adjusted for discrete items, if any, that are taken into account in the relevant period. Each quarter, the Company updates the estimate of the annual effective tax rate, and if the estimated tax rate changes, a cumulative adjustment is recorded. The Company’s income tax expense was $0.1 million for each of the three months ended September 30, 2021 and 2022, and $0.2 million for each of the nine months ended September 30, 2021 and 2022. Tax expense for all periods consists of taxes due on the Company’s U.S. and foreign operations. The effective tax rates for the three and nine months ended September 30, 2021 and 2022 are different from the federal statutory tax rate primarily due to losses for which no tax benefit has been recognized. The Company increased its unrecognized tax benefits in the nine months ended September 30, 2022 by $3.3 million. This increase is primarily attributable to the portion of AFTC revenue recognized in the period attributed to the federal fuel tax the Company collected from its customers and deductions attributed to the unvested Amazon Warrant. The net interest incurred was immaterial for the three and nine months ended September 30, 2021 and 2022. On August 16, 2022, the Inflation Reduction Act of 2022 ("the IRA”) was signed into law. ● Under the IRA, there is a new 15% corporate alternative minimum tax for certain large corporations with at least $1 billion adjusted financial statement income over a consecutive three-year period effective in tax years beginning after December 31, 2022. This provision will not have an impact on the Company. ● Beginning after December 31, 2022, there will be a 1% excise tax on certain share repurchases with certain exceptions. The Company will be subject to the 1% excise tax if it repurchases shares after December 31, 2022. In addition, the IRA offers significant tax incentives targeting energy transaction and renewables: ● Alternative Fuel Tax Credit (“AFTC”) is reinstated to apply retroactively to fuel sales transactions from January 1, 2022 through December 31, 2024. The Company has accordingly recorded the $25.3 million benefit of AFTC. ● The investment tax credit under Section 48 of the Internal Revenue Code is expanded to include Qualified Biogas Property placed in service after December 31, 2022, which is expected to bring significant cash flow for the Renewable Natural Gas projects that the Company has invested or will invest. ● A new tax credit under Section 45Z of the Internal Revenue Code is introduced to apply to transportation fuel produced and sold by the taxpayer from January 1, 2025 through December 31, 2027. The IRA provides a base credit of 20 cents per gallon or $1.00 per gallon if prevailing wage and apprentices requirements are met. The Company expects that the Renewable Natural Gas projects will be eligible for this credit. ● The alternative fuel refueling property credit under Section 30C of the Internal Revenue Code is reinstated for 2022 and extended an additional 10 years to apply to any property placed in service before January 1, 2033. For business property, the credit amount decreases to 6% (from 30%) with a maximum amount of $100,000 per item (previously $30,000 per location per year). Business property meeting prevailing wage and registered apprenticeship requirements may be eligible for a credit amount of 30% ($100,000 maximum). The Internal Revenue Service has been granted broad authority to issue regulations or other guidance that could clarify how these taxes will be applied and credits will be eligible. The Company will continue to evaluate the impact of the IRA as additional information becomes available.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Note 17—Commitments and Contingencies Environmental Matters The Company is subject to federal, state, local and foreign environmental laws and regulations. The Company does not anticipate any expenditures to comply with such laws and regulations that would have a material effect on the Company’s consolidated financial position, results of operations or liquidity. The Company believes that its operations comply, in all material respects, with applicable federal, state, local and foreign environmental laws and regulations. Litigation, Claims and Contingencies The Company may become party to various legal actions that arise in the ordinary course of its business. The Company is also subject to audit by tax and other authorities for varying periods in various federal, state, local and foreign jurisdictions, and disputes may arise during the course of these audits. It is impossible to determine the ultimate liabilities that the Company may incur resulting from any of these lawsuits, claims, proceedings, audits, commitments, contingencies and related matters or the timing of these liabilities, if any. If these matters were to ultimately be resolved unfavorably, it is possible that such an outcome could have a material adverse effect upon the Company’s consolidated financial position, results of operations, or liquidity. The Company does not, however, anticipate such an outcome and believes the ultimate resolution of these matters will not have a material adverse effect on the Company’s consolidated financial position, results of operations, or liquidity. bpJV Capital Call Contribution In December 2021, the bpJV issued the bpJV Capital Call in the amount of $143.2 million, which required bp bp

Leases

Leases	9 Months Ended
	Sep. 30, 2022
Leases
Leases	Note 18—Leases Lessor Accounting The Company leases fueling station equipment to customers pursuant to agreements that contain an option to extend and an end-of-term purchase option. Receivables from these leases are accounted for as finance leases, specifically sales-type leases, and are included in “Other receivables” and “Notes receivable and other long-term assets, net” in the accompanying condensed consolidated balance sheets. The Company recognizes the net investment in the lease as the sum of the lease receivable and the unguaranteed residual value, both of which are measured at the present value using the interest rate implicit in the lease. During each of the three months ended September 30, 2021 and 2022, the Company recognized $0.1 million in “Interest income” on its lease receivables. During each of the nine months ended September 30, 2021 and 2022, the Company recognized $0.3 million in “Interest income” on its lease receivables. The following schedule represents the Company’s maturities of lease receivables as of September 30, 2022 (in thousands): ​ ​ ​ ​ ​ Fiscal year: ​ Remainder of 2022 ​ $ 240 2023 ​ 962 2024 ​ 962 2025 ​ 962 2026 ​ 985 Thereafter ​ 2,374 Total minimum lease payments ​ 6,485 Less amount representing interest ​ (1,588) Present value of lease receivables ​ $ 4,897 ​

Alternative Fuels Excise Tax Cr

Alternative Fuels Excise Tax Credit	9 Months Ended
	Sep. 30, 2022
Alternative Fuel Excise Tax Credit
Alternative Fuels Excise Tax Credit	Note 19—Alternative Fuel Excise Tax Credit Under separate pieces of U.S. federal legislation, the Company had been eligible to receive AFTC for its natural gas vehicle fuel sales made between October 1, 2006 and December 31, 2021. The AFTC was equal to $0.50 per gasoline gallon equivalent of CNG that the Company sold as vehicle fuel, and $0.50 per diesel gallon of LNG that the Company sold as vehicle fuel in 2020 and 2021. The Inflation Reduction Act of 2022, enacted on August 16, 2022, extended AFTC for an additional three years, beginning retroactively to January 1, 2022. AFTC incentive under the extension remained at $0.50 per gasoline gallon equivalent of CNG and $0.50 per diesel gallon of LNG that the Company sells as vehicle fuel through 2024. Based on the service relationship with its customers, either the Company or its customers claim the credit. The Company records its AFTC, if any, as revenue in its condensed consolidated statements of operations because the credits are fully payable to the Company and do not offset income tax liabilities. As such, the credits are not deemed income tax credits under the accounting guidance applicable to income taxes.

Related Party Transactions

Related Party Transactions	9 Months Ended
	Sep. 30, 2022
Related Party Transactions [Abstract]
Related Party Transactions	Note 20—Related Party Transactions TotalEnergies S.E. During the three and nine months ended September 30, 2021, the Company recognized revenue of $1.6 million and $3.1 million, respectively, related to RINs and LNG sold to TotalEnergies and its affiliates in the ordinary course of business and from settlements on commodity swap contracts (Note 6). During the three and nine months ended September 30, 2022, the Company recognized revenue of $2.8 million and $5.7 million, respectively, related to equipment lease revenue and LNG sold to TotalEnergies and its affiliates in the ordinary course of business. As of December 31, 2021 and September 30, 2022, the Company had receivables from TotalEnergies of $1.4 million and $2.6 million, respectively. During the three and nine months ended September 30, 2021, the Company paid TotalEnergies $0.4 million and $1.3 million, respectively, for expenses incurred in the ordinary course of business, settlements on commodity swap contracts (Note 6), and the guaranty fee under the CSA (Note 12). During the three and nine months ended September 30, 2022, the Company paid TotalEnergies $2.5 million and $6.1 million, respectively, for expenses incurred in the ordinary course of business, settlements on commodity swap contracts, and the guaranty fee under the CSA. As of December 31, 2021, the amount due to TotalEnergies was $0.1 million. As of September 30, 2022, total payables due to TotalEnergies were immaterial. SAFE&CEC S.r.l. During the three and nine months ended September 30, 2021, the Company received $0.0 million and $0.2 million, respectively, from SAFE&CEC S.r.l. in the ordinary course of business. During the nine months ended September 30, 2022, the Company received $0.2 million from SAFE&CEC S.r.l. in the ordinary course of business. Cash receipts from SAFE&CEC S.r.l during the three months ended September 30, 2022 were immaterial. The receivables balance as of December 31, 2021 was immaterial. As of September 30, 2022, the Company had receivables from SAFE&CEC S.r.l. of $0.1 million. During the three and nine months ended September 30, 2021, the Company paid SAFE&CEC S.r.l. $3.3 million and $5.8 million, respectively, for parts and equipment in the ordinary course of business. During the three and nine months ended September 30, 2022, the Company paid SAFE&CEC S.r.l. $2.8 million and $8.5 million, respectively, for parts and equipment in the ordinary course of business. As of December 31, 2021 and September 30, 2022, the Company had payables to SAFE&CEC S.r.l. of $0.2 million and $0.7 million, respectively. TotalEnergies JV and bpJV Pursuant to LLC agreements under the TotalEnergies JV and the bpJV, the Company manages the day-to-day operations of RNG projects under the joint ventures in exchange for management fees. During the three and nine months ended September 30, 2022, the Company recognized management fee revenue of $0.3 million and $0.9 million, respectively, related to the TotalEnergies JV and the bpJV. Management fee revenue recognized during the three and nine months ended September 30, 2021 was immaterial. As of December 31, 2021 and September 30, 2022, the Company had receivables from the two joint ventures of $0.4 million and $0.3 million, respectively.

General (Policies)

General (Policies)	9 Months Ended
	Sep. 30, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Presentation	Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries, and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to state fairly the Company’s consolidated financial position as of September 30, 2022, results of operations, comprehensive loss, and stockholders’ equity for the three and nine months ended September 30, 2021 and 2022, and cash flows for the nine months ended September 30, 2021 and 2022. All intercompany accounts and transactions have been eliminated in consolidation. The results of operations for the three and nine months ended September 30, 2021 and 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or any future year. Certain information and disclosures normally included in the notes to consolidated financial statements have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”), but the resultant disclosures contained herein are in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as they apply to interim reporting. The accompanying condensed consolidated financial statements should be read in conjunction with the consolidated financial statements as of and for the year ended December 31, 2021 that are included in the Company’s Annual Report on Form 10-K filed with the SEC on February 24, 2022.
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 amounts reported in the accompanying condensed consolidated financial statements and these notes. Actual results could differ from those estimates and may result in material effects on the Company’s operating results and financial position. Significant estimates made in preparing the accompanying condensed consolidated financial statements include (but are not limited to) those related to revenue recognition, fair value measurements, goodwill and long-lived asset valuations and impairment assessments, income tax valuations, stock-based compensation expense and stock-based sales incentive charges.
Amazon Warrant	Amazon Warrant The Amazon Warrant (defined in Note 14) is accounted for as an equity instrument and measured in accordance with Accounting Standards Codification (“ASC”) 718, Compensation – Stock Compensation Revenue from Contracts with Customers
Recently Adopted Accounting Pronouncements	Recently Adopted Accounting Pronouncements In July 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2021-05, Leases (Topic 842): Lessors–Certain Leases with Variable Lease Payments Recently Issued Accounting Pronouncements In November 2021, the FASB issued ASU No. 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance
Revenue Recognition	Revenue Recognition Overview The Company recognizes revenue when control of the promised goods or services is transferred to its customers, in an amount that reflects the consideration to which it expects to be entitled in exchange for the goods or services. To achieve that core principle, a five-step approach is applied: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue allocated to each performance obligation when the Company satisfies the performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account for revenue recognition.
Basis of Presentation	Basis of Presentation The accompanying interim unaudited condensed consolidated financial statements include the accounts of the Company and its subsidiaries, and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary to state fairly the Company’s consolidated financial position as of September 30, 2022, results of operations, comprehensive loss, and stockholders’ equity for the three and nine months ended September 30, 2021 and 2022, and cash flows for the nine months ended September 30, 2021 and 2022. All intercompany accounts and transactions have been eliminated in consolidation. The results of operations for the three and nine months ended September 30, 2021 and 2022 are not necessarily indicative of the results to be expected for the year ending December 31, 2022 or for any other interim period or any future year. Certain information and disclosures normally included in the notes to consolidated financial statements have been condensed or omitted pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”), but the resultant disclosures contained herein are in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) as they apply to interim reporting. The accompanying condensed consolidated financial statements should be read in conjunction with the consolidated financial statements as of and for the year ended December 31, 2021 that are included in the Company’s Annual Report on Form 10-K filed with the SEC on February 24, 2022.
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 amounts reported in the accompanying condensed consolidated financial statements and these notes. Actual results could differ from those estimates and may result in material effects on the Company’s operating results and financial position. Significant estimates made in preparing the accompanying condensed consolidated financial statements include (but are not limited to) those related to revenue recognition, fair value measurements, goodwill and long-lived asset valuations and impairment assessments, income tax valuations, stock-based compensation expense and stock-based sales incentive charges.
Revenue Recognition	Revenue Recognition Overview The Company recognizes revenue when control of the promised goods or services is transferred to its customers, in an amount that reflects the consideration to which it expects to be entitled in exchange for the goods or services. To achieve that core principle, a five-step approach is applied: (1) identify the contract with a customer, (2) identify the performance obligations in the contract, (3) determine the transaction price, (4) allocate the transaction price to the performance obligations in the contract, and (5) recognize revenue allocated to each performance obligation when the Company satisfies the performance obligation. A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account for revenue recognition.
Amazon Warrant	Amazon Warrant The Amazon Warrant (defined in Note 14) is accounted for as an equity instrument and measured in accordance with Accounting Standards Codification (“ASC”) 718, Compensation – Stock Compensation Revenue from Contracts with Customers
Recently Adopted Accounting Pronouncements and Recently Issued Accounting Pronouncements	Recently Adopted Accounting Pronouncements In July 2021, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2021-05, Leases (Topic 842): Lessors–Certain Leases with Variable Lease Payments Recently Issued Accounting Pronouncements In November 2021, the FASB issued ASU No. 2021-10, Government Assistance (Topic 832): Disclosures by Business Entities about Government Assistance

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	9 Months Ended
	Sep. 30, 2022
Revenue from Contract with Customer [Abstract]
Disaggregation of revenue	The Company is generally the principal in its customer contracts because it has control over the goods and services prior to their transfer to the customer, and as such, revenue is recognized on a gross basis. Sales and usage-based taxes are excluded from revenue. Revenue is recognized net of allowances for returns and any taxes collected from customers, which are subsequently remitted to governmental authorities. The table below presents the Company’s revenue disaggregated by revenue source (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ ​ 2021 2022 2021 2022 Product revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Volume-related ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Fuel sales (1) ​ $ 52,343 ​ $ 78,512 ​ $ 72,237 ​ $ 204,224 Change in fair value of derivative instruments (2) ​ ​ 268 ​ ​ 508 ​ ​ (2,240) ​ ​ (1,606) RIN Credits ​ ​ 8,134 ​ ​ 9,270 ​ ​ 21,916 ​ ​ 26,997 LCFS Credits ​ ​ 5,744 ​ ​ 2,595 ​ ​ 12,976 ​ ​ 10,114 AFTC (3) ​ 5,287 ​ 16,057 ​ 15,008 ​ 16,279 Total volume-related product revenue ​ ​ 71,776 ​ ​ 106,942 ​ ​ 119,897 ​ ​ 256,008 Station construction sales ​ ​ 2,578 ​ ​ 6,418 ​ ​ 13,184 ​ ​ 15,712 Total product revenue ​ 74,354 ​ 113,360 ​ 133,081 ​ 271,720 Service revenue: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Volume-related, O&M services ​ ​ 11,676 ​ ​ 11,982 ​ ​ 30,506 ​ ​ 33,727 Other services ​ ​ 65 ​ ​ 345 ​ ​ 131 ​ ​ 961 Total service revenue ​ ​ 11,741 ​ ​ 12,327 ​ ​ 30,637 ​ ​ 34,688 Total revenue ​ $ 86,095 ​ $ 125,687 ​ $ 163,718 ​ $ 306,408 (1) Includes non-cash stock-based sales incentive contra-revenue charges associated with the Amazon Warrant. For the three and nine months ended September 30, 2021, contra-revenue charges recognized in fuel revenue were $2.2 million and $80.2 million, respectively. For the three and nine months ended September 30, 2022, contra-revenue charges recognized in fuel revenue were $7.0 million and $15.5 million, respectively. See Note 14 for more information. (2) Represents changes in fair value of derivative instruments related to the Company’s commodity swap and customer fueling contracts associated with the Company’s Zero Now truck financing program. The amounts are classified as revenue because the Company’s commodity swap contracts are used to economically offset the risk associated with the diesel-to-natural gas price spread resulting from customer fueling contracts under the Company’s Zero Now truck financing program. See Note 6 for more information about these derivative instruments. (3) Represents the federal alternative fuel excise tax credit (“AFTC”), which was renewed and extended for three years beginning retroactively to January 1, 2022. See Note 19 for more information.
Summary of contract balances	As of December 31, 2021 and September 30, 2022, the Company’s contract balances were as follows (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 ​ 2022 Accounts receivable, net ​ $ 87,433 ​ $ 92,161 ​ ​ ​ ​ ​ ​ Contract assets - current ​ $ 966 ​ $ 2,046 Contract assets - non-current ​ 3,532 ​ 3,115 Contract assets - total ​ $ 4,498 ​ $ 5,161 ​ ​ ​ ​ ​ ​ Contract liabilities - current ​ $ 5,523 ​ $ 4,583 Contract liabilities - non-current ​ — ​ — Contract liabilities - total ​ $ 5,523 ​ $ 4,583

Cash, Cash Equivalents and Re_2

Cash, Cash Equivalents and Restricted Cash (Tables)	9 Months Ended
	Sep. 30, 2022
Cash and Cash Equivalents [Abstract]
Schedule of cash and cash equivalents	Cash, cash equivalents and restricted cash as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 ​ 2022 Current assets: ​ ​ Cash and cash equivalents ​ $ 99,448 ​ $ 23,123 Total cash and cash equivalents ​ $ 99,448 ​ $ 23,123 ​ ​ ​ ​ ​ ​ ​ Long-term assets: ​ ​ Restricted cash - held as collateral ​ $ 7,008 ​ $ — Total restricted cash ​ $ 7,008 ​ $ — ​ ​ ​ ​ ​ ​ ​ Total cash, cash equivalents and restricted cash ​ $ 106,456 ​ $ 23,123
Schedule of components of restricted cash	Cash, cash equivalents and restricted cash as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 ​ 2022 Current assets: ​ ​ Cash and cash equivalents ​ $ 99,448 ​ $ 23,123 Total cash and cash equivalents ​ $ 99,448 ​ $ 23,123 ​ ​ ​ ​ ​ ​ ​ Long-term assets: ​ ​ Restricted cash - held as collateral ​ $ 7,008 ​ $ — Total restricted cash ​ $ 7,008 ​ $ — ​ ​ ​ ​ ​ ​ ​ Total cash, cash equivalents and restricted cash ​ $ 106,456 ​ $ 23,123

Short-Term Investments (Tables)

Short-Term Investments (Tables)	9 Months Ended
	Sep. 30, 2022
Investments, Debt and Equity Securities [Abstract]
Summary of short-term investments	Short-term investments as of December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Estimated ​ Cost Gain (Loss) Fair Value Municipal bonds and notes ​ $ 6,001 ​ $ (1) ​ $ 6,000 Zero coupon bonds ​ 123,210 ​ (18) ​ 123,192 Certificates of deposit ​ 530 ​ — ​ 530 Total short-term investments ​ $ 129,741 ​ $ (19) ​ $ 129,722 ​ Short-term investments as of September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross ​ ​ ​ ​ ​ Amortized ​ Unrealized ​ Estimated ​ Cost Gain (Loss) Fair Value Zero coupon bonds ​ $ 111,154 ​ $ (695) ​ $ 110,459 Certificates of deposit ​ ​ 530 ​ ​ — ​ ​ 530 Total short-term investments ​ $ 111,684 ​ $ (695) ​ $ 110,989

Derivative Instruments and He_2

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2022
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Summary of commodity derivative activity	Derivatives and embedded derivatives as of December 31, 2021 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Amounts ​ Gross Amounts ​ Net Amount ​ Recognized Offset Presented Assets: ​ ​ ​ Fueling agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ Prepaid expenses and other current assets ​ $ 2,038 ​ $ — ​ $ 2,038 Notes receivable and other long-term assets, net ​ ​ 4,738 ​ ​ — ​ ​ 4,738 Total derivative assets ​ $ 6,776 ​ $ — ​ $ 6,776 Liabilities: ​ ​ ​ Commodity swaps: ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of derivative liabilities, related party ​ $ 1,900 ​ $ — ​ $ 1,900 Long-term portion of derivative liabilities, related party ​ 2,483 ​ — ​ 2,483 Total derivative liabilities ​ $ 4,383 ​ $ — ​ $ 4,383 ​ Derivatives and embedded derivatives as of September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Gross Amounts ​ Gross Amounts ​ Net Amount ​ Recognized Offset Presented Assets: ​ ​ ​ Fueling agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ Prepaid expenses and other current assets ​ $ 2,619 ​ $ — ​ $ 2,619 Notes receivable and other long-term assets, net ​ ​ 3,827 ​ ​ — ​ ​ 3,827 Total derivative assets ​ $ 6,446 ​ $ — ​ $ 6,446 Liabilities: ​ ​ ​ Commodity swaps: ​ ​ ​ ​ ​ ​ ​ ​ ​ Current portion of derivative liabilities, related party ​ $ 3,912 ​ $ — ​ $ 3,912 Long-term portion of derivative liabilities, related party ​ ​ 1,694 ​ ​ — ​ ​ 1,694 Fueling agreements: ​ ​ ​ ​ ​ ​ ​ ​ ​ Accrued liabilities ​ ​ 14 ​ ​ — ​ ​ 14 Other long-term liabilities ​ ​ 39 ​ ​ — ​ ​ 39 Total derivative liabilities ​ $ 5,659 ​ $ — ​ $ 5,659
Schedule of weighted-average price of open commodity swap contract	The following table reflects the weighted-average price of open commodity swap contracts as of December 31, 2021 and September 30, 2022, by year with associated volumes: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ September 30, 2022 ​ ​ Volumes ​ Weighted-Average Price per ​ Volumes ​ Weighted-Average Price per Year (Diesel Gallons) Diesel Gallon (Diesel Gallons) Diesel Gallon 2022 5,000,000 ​ $ 3.18 1,250,000 ​ $ 3.22 2023 5,000,000 ​ $ 3.18 5,000,000 ​ $ 3.22 2024 1,875,000 ​ $ 3.18 1,875,000 ​ $ 3.22

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2022
Fair Value Disclosures [Abstract]
Schedule of estimated fair value of outstanding commodity swap contracts and embedded derivatives	The Company estimated the fair value of its outstanding commodity swap contracts based on the following inputs as of December 31, 2021 and September 30, 2022: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ September 30, 2022 Significant Unobservable Inputs Input Range Weighted Average Input Range Weighted Average ULSD Gulf Coast Forward Curve ​ $2.03 - $2.15 ​ $ 2.11 ​ $ 2.19 - $ 2.58 ​ $ 2.38 Historical Differential to PADD 3 Diesel ​ $0.87 - $1.58 ​ $ 1.03 ​ $ 0.87 - $ 1.60 ​ $ 1.10 Historical Differential to PADD 5 Diesel ​ $1.82 - $2.69 ​ $ 2.13 ​ $ 1.91 - $ 3.05 ​ $ 2.26 ​ The Company estimated the fair value of embedded derivatives in its fueling agreements under the Zero Now ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ September 30, 2022 Significant Unobservable Inputs Input Range Weighted Average Input Range Weighted Average ULSD Gulf Coast Forward Curve ​ $2.03 - $2.15 ​ $ 2.11 ​ $ 2.19 - $ 2.58 ​ $ 2.38 Historical Differential to PADD 3 Diesel ​ $0.87 - $1.58 ​ $ 1.03 ​ $ 0.87 - $ 1.60 ​ $ 1.10 Historical Differential to PADD 5 Diesel ​ $1.82 - $2.69 ​ $ 2.13 ​ $ 1.91 - $ 3.05 ​ $ 2.26
Schedule of information by level for assets and liabilities that are measured at fair value on a recurring basis	The following tables provide information by level for assets and liabilities that are measured at fair value on a recurring basis as of December 31, 2021 and September 30, 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 Level 1 Level 2 Level 3 Assets: ​ ​ ​ ​ Available-for-sale securities (1) ​ ​ ​ ​ Municipal bonds and notes ​ $ 6,000 ​ $ — ​ $ 6,000 ​ $ — Zero coupon bonds ​ 123,192 ​ — ​ 123,192 ​ — Certificates of deposit (1) ​ 530 ​ — ​ 530 ​ — Embedded derivatives (3) ​ ​ 6,776 ​ ​ — ​ ​ — ​ ​ 6,776 Liabilities: ​ ​ ​ ​ ​ Commodity swap contracts (2) ​ $ 4,383 ​ $ — ​ $ — ​ $ 4,383 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 Level 1 Level 2 Level 3 Assets: ​ ​ ​ Available-for-sale securities (1) ​ ​ ​ ​ Zero coupon bonds ​ $ 110,459 ​ $ — ​ $ 110,459 ​ $ — Certificates of deposit (1) ​ ​ 530 ​ ​ — ​ ​ 530 ​ ​ — Embedded derivatives (3) ​ ​ 6,446 ​ ​ — ​ ​ — ​ ​ 6,446 Liabilities: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Commodity swap contracts (2) ​ $ 5,606 ​ $ — ​ $ — ​ $ 5,606 Embedded derivatives (3) ​ ​ 53 ​ ​ — ​ ​ — ​ ​ 53 ​ (1) Included in "Short-term investments" in the accompanying condensed consolidated balance sheets. See Note 5 for more information. (2) Included in "Derivative liabilities, related party" and "Long-term portion of derivative liabilities, related party" as of December 31, 2021 and September 30, 2022 in the accompanying condensed consolidated balance sheets. See Note 6 for more information. (3) Included in "Prepaid expenses and other current assets" and “Notes receivable and other long-term assets, net" as of December 31, 2021, and in "Prepaid expenses and other current assets," “Notes receivable and other long-term assets, net," “Accrued liabilities” and “Other long-term liabilities” as of September 30, 2022 in the accompanying condensed consolidated balance sheets. See Note 6 for more information.
Schedule of reconciliation of the beginning and ending balances of items measured at fair value on a recurring basis that used significant unobservable inputs (Level 3)	The following tables provide a reconciliation of the beginning and ending balances of items measured at fair value on a recurring basis as shown in the tables above that used significant unobservable inputs (Level 3), as well as the change in unrealized gains or losses for the periods included in earnings (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets: ​ Assets: ​ Liabilities: ​ Liabilities: ​ ​ Commodity ​ Embedded ​ Commodity ​ Embedded ​ Swap Contracts Derivatives ​ Swap Contracts ​ Derivatives Balance as of June 30, 2021 ​ $ — ​ $ 5,069 ​ $ (1,693) ​ $ — Settlements, net ​ ​ — ​ ​ — ​ ​ 265 ​ ​ — Total gain (loss) ​ 587 ​ (1,926) ​ 1,428 ​ (87) Balance as of September 30, 2021 ​ $ 587 ​ $ 3,143 ​ $ — ​ $ (87) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of June 30, 2022 ​ $ — ​ $ 11,345 ​ $ (11,034) ​ $ (32) Settlements, net ​ ​ — ​ ​ — ​ ​ 1,942 ​ ​ — Total gain (loss) ​ — ​ ​ (4,899) ​ ​ 3,486 ​ ​ (21) Balance as of September 30, 2022 ​ $ — ​ $ 6,446 ​ $ (5,606) ​ $ (53) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in unrealized gain (loss) for the three months ended September 30, 2021 included in earnings ​ $ 587 ​ $ (1,926) ​ $ 1,693 ​ $ (87) Change in unrealized gain (loss) for the three months ended September 30, 2022 included in earnings ​ $ — ​ $ (4,899) ​ $ 5,428 ​ $ (21) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Assets: ​ Assets: ​ Liabilities: ​ Liabilities: ​ ​ Commodity ​ Embedded ​ Commodity ​ Embedded ​ Swap Contracts Derivatives ​ Swap Contracts ​ Derivatives Balance as of December 31, 2020 ​ $ 5,648 ​ $ 791 ​ $ — ​ $ (556) Settlements, net ​ ​ (225) ​ ​ — ​ ​ 614 ​ ​ — Total gain (loss) ​ (4,836) ​ ​ 2,352 ​ ​ (614) ​ ​ 469 Balance as of September 30, 2021 ​ $ 587 ​ $ 3,143 ​ $ — ​ $ (87) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Balance as of December 31, 2021 ​ $ — ​ $ 6,776 ​ $ (4,383) ​ $ — Settlements, net ​ ​ — ​ ​ — ​ ​ 5,843 ​ ​ — Total gain (loss) ​ — ​ ​ (330) ​ ​ (7,066) ​ ​ (53) Balance as of September 30, 2022 ​ $ — ​ $ 6,446 ​ $ (5,606) ​ $ (53) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Change in unrealized gain (loss) for the nine months ended September 30, 2021 included in earnings ​ $ (5,061) ​ $ 2,352 ​ $ — ​ $ 469 Change in unrealized gain (loss) for the nine months ended September 30, 2022 included in earnings ​ $ — ​ $ (330) ​ $ (1,223) ​ $ (53) ​

Other Receivables (Tables)

Other Receivables (Tables)	9 Months Ended
	Sep. 30, 2022
Receivables [Abstract]
Schedule of other receivables	Other receivables as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 2022 Loans to customers to finance vehicle purchases ​ $ 419 ​ $ 512 Accrued customer billings ​ 4,417 ​ 3,946 Fuel tax credits ​ 12,684 ​ 27,402 Other ​ 6,927 ​ 3,252 Total other receivables ​ $ 24,447 ​ $ 35,112

Inventory (Tables)

Inventory (Tables)	9 Months Ended
	Sep. 30, 2022
Inventory Disclosure [Abstract]
Schedule of inventories	Inventory as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ ​ 2021 ​ 2022 Raw materials and spare parts ​ $ 31,302 ​ $ 35,927 Total inventory ​ $ 31,302 ​ $ 35,927

Land, Property and Equipment (T

Land, Property and Equipment (Tables)	9 Months Ended
	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Summary of land, property and equipment	Land, property and equipment, net as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, September 30, ​ 2021 2022 Land ​ $ 3,476 ​ $ 3,476 LNG liquefaction plants ​ 94,633 ​ 94,633 Station equipment ​ 354,699 ​ 353,132 Trailers ​ 72,783 ​ 73,117 Other equipment ​ 93,135 ​ 95,799 Construction in progress ​ 74,963 ​ 76,660 ​ ​ 693,689 ​ 696,817 Less accumulated depreciation ​ (431,928) ​ (447,915) Total land, property and equipment, net ​ $ 261,761 ​ $ 248,902

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	9 Months Ended
	Sep. 30, 2022
Payables and Accruals [Abstract]
Schedule of accrued liabilities	Accrued liabilities as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, ​ September 30, ​ 2021 2022 Accrued alternative fuels incentives (1) ​ $ 28,106 ​ $ 30,948 Accrued employee benefits ​ 4,547 ​ 4,476 Accrued gas and equipment purchases ​ 17,158 ​ 22,532 Accrued interest ​ 893 ​ 1,685 Accrued property and other taxes ​ 3,369 ​ 4,075 Accrued salaries and wages ​ 8,172 ​ 6,687 Embedded derivatives ​ ​ — ​ ​ 14 Other (2) ​ 12,914 ​ 14,783 Total accrued liabilities ​ $ 75,159 ​ $ 85,200 (1) Includes amount for RINs, LCFS Credits, and AFTC payable to third parties. (2) No individual item in “Other” exceeds 5% of total current liabilities .

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2022
Debt Disclosure [Abstract]
Schedule of long-term debt	Debt obligations as of December 31, 2021 and September 30, 2022 consisted of the following (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ December 31, 2021 ​ ​ ​ Unamortized Debt Balance, Net of ​ ​ Principal Balance ​ Financing Costs ​ Financing Costs NG Advantage debt ​ $ 25,832 $ 72 ​ $ 25,760 SG Facility ​ ​ 9,500 ​ ​ — ​ ​ 9,500 Other debt ​ 800 ​ — ​ 800 Total debt ​ 36,132 ​ 72 ​ 36,060 Less amounts due within one year ​ (12,868) ​ (23) ​ (12,845) Total long-term debt ​ $ 23,264 ​ $ 49 ​ $ 23,215 ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ September 30, 2022 ​ ​ ​ Unamortized Debt Balance, Net of ​ ​ Principal Balance ​ Financing Costs ​ Financing Costs NG Advantage debt ​ $ 26,515 ​ $ 108 ​ $ 26,407 SG Facility ​ ​ 2,000 ​ ​ — ​ ​ 2,000 Other debt ​ 148 ​ ​ — ​ ​ 148 Total debt ​ 28,663 ​ 108 ​ 28,555 Less amounts due within one year ​ (4,198) ​ ​ (33) ​ ​ (4,165) Total long-term debt ​ $ 24,465 ​ $ 75 ​ $ 24,390

Net Income (Loss) Per Share (Ta

Net Income (Loss) Per Share (Tables)	9 Months Ended
	Sep. 30, 2022
Earnings Per Share [Abstract]
Schedule of information required to compute basic and diluted net loss per share	The following table sets forth the computations of basic and diluted earnings (loss) per share for the three and nine months ended September 30, 2021 and 2022 (in thousands except share and per share amounts): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ September 30, ​ September 30, ​ ​ 2021 2022 2021 2022 Net loss attributable to Clean Energy Fuels Corp. ​ $ (3,934) ​ $ (8,973) ​ $ (90,770) ​ $ (46,399) ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Weighted-average common shares outstanding ​ 223,008,202 ​ 222,239,376 ​ 209,771,584 ​ 222,409,802 Dilutive effect of potential common shares from restricted stock units, stock options and stock warrants ​ — ​ — ​ — ​ — Weighted-average common shares outstanding - diluted ​ 223,008,202 ​ 222,239,376 ​ 209,771,584 ​ 222,409,802 Basic and diluted loss per share ​ $ (0.02) ​ $ (0.04) ​ $ (0.43) ​ $ (0.21)
Schedule of potentially dilutive securities that have been excluded from the diluted net loss per share calculations because their effect would have been antidilutive	The following potentially dilutive securities have been excluded from the diluted net loss per share calculations because their effect would have been antidilutive. Although these securities were antidilutive for these periods, they could be dilutive in future periods. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2021 2022 2021 2022 Stock options ​ 8,896,688 ​ ​ 16,170,384 ​ ​ 8,896,688 ​ ​ 16,170,384 Restricted stock units ​ 1,241,306 ​ ​ 680,191 ​ ​ 1,241,306 ​ ​ 680,191 Amazon warrant shares ​ ​ 58,767,714 ​ ​ 58,767,714 ​ ​ 58,767,714 ​ ​ 58,767,714 Total ​ ​ 68,905,708 ​ ​ 75,618,289 ​ ​ 68,905,708 ​ ​ 75,618,289

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2022
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Summary of compensation expense and related income tax benefit related to the stock-based compensation expense recognized	The following table summarizes the compensation expense and related income tax benefit related to the Company’s stock-based compensation arrangements recognized in the accompanying condensed consolidated statements of operations during the three and nine months ended September 30, 2021 and 2022 (in thousands): ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ Three Months Ended ​ Nine Months Ended ​ ​ September 30, ​ September 30, ​ 2021 2022 2021 2022 Stock-based compensation expense, net of $0 tax in 2021 and 2022 ​ $ 3,435 ​ $ 5,964 ​ $ 10,220 ​ $ 20,685
Schedule of warrant activity	The following table summarizes the Amazon Warrant activity for the nine months ended September 30, 2022: ​ ​ ​ ​ ​ Warrant ​ Shares Outstanding and unvested as of December 31, 2021 44,077,779 Granted — Vested (1,175,408) Outstanding and unvested as of September 30, 2022 42,902,371

Leases (Tables)

Leases (Tables)	9 Months Ended
	Sep. 30, 2022
Leases
Schedule of maturities of lease receivables	The following schedule represents the Company’s maturities of lease receivables as of September 30, 2022 (in thousands): ​ ​ ​ ​ ​ Fiscal year: ​ Remainder of 2022 ​ $ 240 2023 ​ 962 2024 ​ 962 2025 ​ 962 2026 ​ 985 Thereafter ​ 2,374 Total minimum lease payments ​ 6,485 Less amount representing interest ​ (1,588) Present value of lease receivables ​ $ 4,897

Revenue from Contracts with C_3

Revenue from Contracts with Customers - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Revenue from Contracts with Customers
Revenue	$ 125,687	$ 86,095	$ 306,408	$ 163,718
Contra revenue charge			15,500	80,237
Fuel Sales
Revenue from Contracts with Customers
Revenue	78,512	52,343	204,224	72,237
RIN Credits
Revenue from Contracts with Customers
Revenue	9,270	8,134	26,997	21,916
LCFS Credits
Revenue from Contracts with Customers
Revenue	2,595	5,744	10,114	12,976
AFTC
Revenue from Contracts with Customers
Revenue	16,057	5,287	16,279	15,008
Total volume-related product revenue
Revenue from Contracts with Customers
Revenue	106,942	71,776	256,008	119,897
Station construction sales
Revenue from Contracts with Customers
Revenue	6,418	2,578	15,712	13,184
Product revenue
Revenue from Contracts with Customers
Revenue	113,360	74,354	271,720	133,081
Volume-related, O&M services
Revenue from Contracts with Customers
Revenue	11,982	11,676	33,727	30,506
Other services
Revenue from Contracts with Customers
Revenue	345	65	961	131
Service revenue
Revenue from Contracts with Customers
Revenue	12,327	11,741	34,688	30,637
Volume-Related
Revenue from Contracts with Customers
Gain (loss) due to changes in fair value	508	268	(1,606)	(2,240)
Contra revenue charge	$ 7,000	$ 2,200	$ 15,500	$ 80,200

Revenue from Contracts with C_4

Revenue from Contracts with Customers - Remaining Performance Obligations (Details) $ in Millions	Sep. 30, 2022 USD ($)
Remaining Performance Obligations
Revenue, remaining performance obligation, amount	$ 23.1
Minimum
Remaining Performance Obligations
Revenue, remaining performance obligation, expected timing of satisfaction, period	12 months
Maximum
Remaining Performance Obligations
Revenue, remaining performance obligation, expected timing of satisfaction, period	24 months

Revenue from Contracts with C_5

Revenue from Contracts with Customers - Contract Balances (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Accounts receivable, net	$ 92,161	$ 87,433
Contract assets - current	2,046	966
Contract assets - non-current	3,115	3,532
Contract assets - total	5,161	4,498
Contract liabilities - current	4,583	5,523
Contract liabilities - total	$ 4,583	$ 5,523

Revenue from Contracts with C_6

Revenue from Contracts with Customers - Contract Liabilities (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Revenue from Contract with Customer [Abstract]
Contract with customer, liability, revenue recognized	$ 2.5	$ 1.5

Investments in Other Entities_2

Investments in Other Entities and Noncontrolling Interest in a Subsidiary - Total Joint Venture (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Nov. 01, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Oct. 12, 2021	Mar. 03, 2021
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments		$ (728)	$ (355)	$ (3,598)	$ (660)
TotalEnergies
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments		0		100
Investment balance		$ 4,600		$ 4,600		$ 4,700
TotalEnergies | ADG RNG Production Facilities
Schedule of Equity Method Investments [Line Items]
Investment commitment of equity in production projects								$ 400,000
Investment commitment in joint venture								50,000
TotalEnergies | ADG RNG Production Facilities | TotalEnergies S.E.
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture								$ 50,000
TotalEnergies | DR Development Agreement
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture							$ 7,000
Initial contribution commitment	$ 4,800
TotalEnergies | DR Development Agreement | TotalEnergies S.E.
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture							$ 7,000
Initial contribution commitment	$ 4,800

Investments in Other Entities_3

Investments in Other Entities and Noncontrolling Interest in a Subsidiary - bp Joint Venture (Details) - USD ($) $ in Thousands, shares in Millions			1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 21, 2021	Apr. 13, 2021	Jun. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Mar. 30, 2022	Dec. 31, 2021	Dec. 18, 2020
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments				$ (728)	$ (355)	$ (3,598)	$ (660)
BP Products North America | bp Loan
Schedule of Equity Method Investments [Line Items]
Debt issuance amount										$ 50,000
bpJV | ADG RNG Production Facilities
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture	$ 50,200	$ 30,000		$ 38,100		$ 38,100
Additional commitment in joint venture		$ 20,000
Initial contribution commitment			$ 30,000
Ownership interest (as a percent)				50%		50%
Income (loss) from equity method investments				$ (200)		$ (2,200)
Investment balance				157,300		157,300			$ 69,800
bpJV | ADG RNG Production Facilities | bpJV Capital Call
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture				$ 51,600		$ 51,600			71,600
Capital call contribution amount									143,200
bpJV | ADG RNG Production Facilities | bpJV Capital Call 2
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture								$ 38,100
Capital call contribution amount								76,200
bpJV | ADG RNG Production Facilities | Class A Units
Schedule of Equity Method Investments [Line Items]
Number of units received		30
Payments to acquire units in joint venture	20,000
Priority Return to acquire additional units	$ 200
bpJV | ADG RNG Production Facilities | bp
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture		$ 50,000
Ownership interest (as a percent)				50%		50%
bpJV | ADG RNG Production Facilities | bp | bpJV Capital Call
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture									$ 71,600
bpJV | ADG RNG Production Facilities | bp | bpJV Capital Call 2
Schedule of Equity Method Investments [Line Items]
Investment commitment in joint venture								$ 38,100
bpJV | ADG RNG Production Facilities | bp | Class A Units
Schedule of Equity Method Investments [Line Items]
Number of units received		30
bpJV | ADG RNG Production Facilities | bp | Class B Units
Schedule of Equity Method Investments [Line Items]
Number of units received		20

Investments in Other Entities_4

Investments in Other Entities and Noncontrolling Interest in a Subsidiary - SAFE&CEC S.r.l. (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Dec. 29, 2017
Schedule of Equity Method Investments [Line Items]
Income (loss) from equity method investments	$ (728)	$ (355)	$ (3,598)	$ (660)
SAFE&CEC S.r.l.
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)						49%
Income (loss) from equity method investments	300	$ 100	600	$ 0
Investment balance	$ 20,800		$ 20,800		$ 23,900
SAFE&CEC S.r.l. | Landi Renzo S.p.A.
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)						51%

Investments in Other Entities_5

Investments in Other Entities and Noncontrolling Interest in a Subsidiary - NG Advantage (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Oct. 14, 2014
Schedule of Equity Method Investments [Line Items]
Loss from noncontrolling interest	$ 115	$ 224	$ 627	$ 784
Investments carried at cost	8,000		8,000
NG Advantage
Schedule of Equity Method Investments [Line Items]
Loss from noncontrolling interest	100	$ 200	600	$ 800
Noncontrolling interest, fair value	$ 7,700		$ 7,700		$ 8,300
NG Advantage | Common unit purchase agreement
Schedule of Equity Method Investments [Line Items]
Ownership interest acquired						53.30%
Ownership interest after transaction (as a percent)			93.30%

Cash, Cash Equivalents and Re_3

Cash, Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Jan. 31, 2022	Dec. 31, 2021	Sep. 30, 2021	Dec. 31, 2020
Restricted Cash
Cash and cash equivalents	$ 23,123		$ 99,448
Total cash and cash equivalents	23,123		99,448
Total restricted cash	0		7,008
Total cash, cash equivalents and restricted cash	23,123		106,456	$ 146,912	$ 119,977
Amount in excess of FDIC and CDIC limits	21,700		98,000
Held as collateral
Restricted Cash
Total restricted cash	$ 0	$ 7,000	$ 7,008

Short-Term Investments (Details

Short-Term Investments (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 111,684	$ 129,741
Gross Unrealized Gain (Loss)	(695)	(19)
Estimated Fair Value	110,989	129,722
Municipal bonds and notes
Debt Securities, Available-for-sale [Line Items]
Amortized Cost		6,001
Gross Unrealized Gain (Loss)		(1)
Estimated Fair Value		6,000
Zero coupon bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	111,154	123,210
Gross Unrealized Gain (Loss)	(695)	(18)
Estimated Fair Value	110,459	123,192
Certificates of deposit
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	530	530
Gross Unrealized Gain (Loss)	0	0
Estimated Fair Value	$ 530	$ 530

Derivative Instruments and He_3

Derivative Instruments and Hedging Activities - Narrative (Details) - Not Designated as Hedging Instrument - Commodity swaps gal in Millions	1 Months Ended	9 Months Ended	12 Months Ended
	Oct. 31, 2018 contract gal	Sep. 30, 2022 $ / gal gal	Dec. 31, 2021 $ / gal gal
Derivative [Line Items]
Derivative asset, number of instruments held | contract	2
Volumes (Diesel Gallons) | gal	5	8.1	11.9
Weighted-average price per diesel gallon (in usd per gallon) | $ / gal		3.22	3.22

Derivative Instruments and He_4

Derivative Instruments and Hedging Activities - Summary of Commodity Derivative Activity (Details) - Not Designated as Hedging Instrument - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Derivative Assets
Gross Amounts Recognized	$ 6,446	$ 6,776
Gross Amounts Offset	0	0
Net Amount Presented	6,446	6,776
Derivative Liability
Gross Amounts Recognized	5,659	4,383
Gross Amounts Offset	0	0
Net Amount Presented	5,659	4,383
Notes receivable and other long-term assets, net | Fueling agreements
Derivative Assets
Gross Amounts Recognized	3,827	4,738
Gross Amounts Offset	0	0
Net Amount Presented	3,827	4,738
Prepaid expenses and other current assets | Fueling agreements
Derivative Assets
Gross Amounts Recognized	2,619	2,038
Gross Amounts Offset	0	0
Net Amount Presented	2,619	2,038
Current portion of derivative liabilities, related party | Commodity swaps
Derivative Assets
Gross Amounts Offset		0
Derivative Liability
Gross Amounts Recognized	3,912	1,900
Gross Amounts Offset	0
Net Amount Presented	3,912	1,900
Long-term portion of derivative liabilities, related party | Commodity swaps
Derivative Assets
Gross Amounts Offset		0
Derivative Liability
Gross Amounts Recognized	1,694	2,483
Gross Amounts Offset	0
Net Amount Presented	1,694	$ 2,483
Accrued liabilities | Fueling agreements
Derivative Assets
Gross Amounts Recognized	14
Gross Amounts Offset	0
Net Amount Presented	14
Other long-term liabilities | Fueling agreements
Derivative Assets
Gross Amounts Recognized	39
Gross Amounts Offset	0
Net Amount Presented	$ 39

Derivative Instruments and He_5

Derivative Instruments and Hedging Activities - Schedule of Weighted-Average Price of Open Commodity Swap Contracts (Details) - Not Designated as Hedging Instrument	9 Months Ended	12 Months Ended
	Sep. 30, 2022 $ / gal gal	Dec. 31, 2021 $ / gal gal
Commodity Swap 2022
Derivative [Line Items]
Volumes (Diesel Gallons) | gal	1,250,000	5,000,000
Weighted-Average Price per Diesel Gallon (in usd per gallon) | $ / gal	3.22	3.18
Commodity Swap 2023
Derivative [Line Items]
Volumes (Diesel Gallons) | gal	5,000,000	5,000,000
Weighted-Average Price per Diesel Gallon (in usd per gallon) | $ / gal	3.22	3.18
Commodity Swap 2024
Derivative [Line Items]
Volumes (Diesel Gallons) | gal	1,875,000	1,875,000
Weighted-Average Price per Diesel Gallon (in usd per gallon) | $ / gal	3.22	3.18

Fair Value Measurements - Commo

Fair Value Measurements - Commodity Swap Contracts (Details) - Not Designated as Hedging Instrument - Valuation Technique, Discounted Cash Flow - Level 3	Sep. 30, 2022	Dec. 31, 2021
Commodity swaps | Minimum | ULSD Gulf Coast Forward Curve
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.19	2.03
Commodity swaps | Minimum | Historical Differential to PADD 3 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.87	0.87
Commodity swaps | Minimum | Historical Differential to PADD 5 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	1.91	1.82
Commodity swaps | Maximum | ULSD Gulf Coast Forward Curve
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.58	2.15
Commodity swaps | Maximum | Historical Differential to PADD 3 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	1.60	1.58
Commodity swaps | Maximum | Historical Differential to PADD 5 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	3.05	2.69
Commodity swaps | Weighted Average | ULSD Gulf Coast Forward Curve
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.38	2.11
Commodity swaps | Weighted Average | Historical Differential to PADD 3 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	1.10	1.03
Commodity swaps | Weighted Average | Historical Differential to PADD 5 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.26	2.13
Fueling agreements | Minimum | ULSD Gulf Coast Forward Curve
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.19	2.03
Fueling agreements | Minimum | Historical Differential to PADD 3 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	0.87	0.87
Fueling agreements | Minimum | Historical Differential to PADD 5 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	1.91	1.82
Fueling agreements | Maximum | ULSD Gulf Coast Forward Curve
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.58	2.15
Fueling agreements | Maximum | Historical Differential to PADD 3 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	1.60	1.58
Fueling agreements | Maximum | Historical Differential to PADD 5 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	3.05	2.69
Fueling agreements | Weighted Average | ULSD Gulf Coast Forward Curve
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.38	2.11
Fueling agreements | Weighted Average | Historical Differential to PADD 3 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	1.10	1.03
Fueling agreements | Weighted Average | Historical Differential to PADD 5 Diesel
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative asset, measurement input	2.26	2.13

Fair Value Measurements - Trans

Fair Value Measurements - Transfers (Details) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2022	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Asset transferred level 3 net	$ 0	$ 0
Liabilities transferred level 3 net	$ 0	$ 0

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Assets:
Available-for-sale securities	$ 110,989	$ 129,722
Short-term investments	110,989	129,722
Municipal bonds and notes
Assets:
Available-for-sale securities		6,000
Zero coupon bonds
Assets:
Available-for-sale securities	110,459	123,192
Certificates of deposit
Assets:
Available-for-sale securities	530	530
Fair value measured on recurring basis | Municipal bonds and notes
Assets:
Available-for-sale securities		6,000
Fair value measured on recurring basis | Zero coupon bonds
Assets:
Available-for-sale securities	110,459	123,192
Fair value measured on recurring basis | Certificates of deposit
Assets:
Short-term investments	530	530
Fair value measured on recurring basis | Commodity swap contracts
Liabilities:
Derivative liabilities	5,606	4,383
Fair value measured on recurring basis | Embedded derivatives
Assets:
Derivative assets	6,446	6,776
Liabilities:
Derivative liabilities	53
Fair value measured on recurring basis | Level 1 | Municipal bonds and notes
Assets:
Available-for-sale securities		0
Fair value measured on recurring basis | Level 1 | Zero coupon bonds
Assets:
Available-for-sale securities	0	0
Fair value measured on recurring basis | Level 1 | Certificates of deposit
Assets:
Short-term investments	0	0
Fair value measured on recurring basis | Level 1 | Commodity swap contracts
Liabilities:
Derivative liabilities	0	0
Fair value measured on recurring basis | Level 1 | Embedded derivatives
Assets:
Derivative assets	0	0
Liabilities:
Derivative liabilities	0
Fair value measured on recurring basis | Level 2 | Municipal bonds and notes
Assets:
Available-for-sale securities		6,000
Fair value measured on recurring basis | Level 2 | Zero coupon bonds
Assets:
Available-for-sale securities	110,459	123,192
Fair value measured on recurring basis | Level 2 | Certificates of deposit
Assets:
Short-term investments	530	530
Fair value measured on recurring basis | Level 2 | Commodity swap contracts
Liabilities:
Derivative liabilities	0	0
Fair value measured on recurring basis | Level 2 | Embedded derivatives
Assets:
Derivative assets	0	0
Liabilities:
Derivative liabilities	0
Fair value measured on recurring basis | Level 3 | Municipal bonds and notes
Assets:
Available-for-sale securities		0
Fair value measured on recurring basis | Level 3 | Zero coupon bonds
Assets:
Available-for-sale securities	0	0
Fair value measured on recurring basis | Level 3 | Certificates of deposit
Assets:
Short-term investments	0	0
Fair value measured on recurring basis | Level 3 | Commodity swap contracts
Liabilities:
Derivative liabilities	5,606	4,383
Fair value measured on recurring basis | Level 3 | Embedded derivatives
Assets:
Derivative assets	6,446	$ 6,776
Liabilities:
Derivative liabilities	$ 53

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value Recognition - Assets (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reconciliation of the beginning and ending balances of assets measured at fair value using significant unobservable inputs (Level 3)
Fair Value, Asset, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax
Fair Value, Asset, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income [Extensible List]	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax
Commodity swap contracts
Reconciliation of the beginning and ending balances of assets measured at fair value using significant unobservable inputs (Level 3)
Beginning balance	$ 0	$ 0		$ 5,648
Settlements, net	0	0		(225)
Total gain (loss)	0	587		(4,836)
Ending balance	0	587	$ 0	587
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	0	587		(5,061)
Embedded derivatives
Reconciliation of the beginning and ending balances of assets measured at fair value using significant unobservable inputs (Level 3)
Beginning balance	11,345	5,069	6,776	791
Settlements, net	0	0
Total gain (loss)	(4,899)	(1,926)	(330)	2,352
Ending balance	6,446	3,143	6,446	3,143
Fair Value, Assets Measured on Recurring Basis, Change in Unrealized Gain (Loss)	$ (4,899)	$ (1,926)	$ (330)	$ 2,352

Fair Value Measurements - Fai_2

Fair Value Measurements - Fair Value Recognition - Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Reconciliation of the beginning and ending balances of liabilities measured at fair value using significant unobservable inputs (Level 3)
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax
Fair Value, Liability, Recurring Basis, Still Held, Unrealized Gain (Loss), Statement of Income [Extensible List]	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax
Commodity swap contracts
Reconciliation of the beginning and ending balances of liabilities measured at fair value using significant unobservable inputs (Level 3)
Beginning Balance	$ (11,034)	$ (1,693)	$ (4,383)
Settlements, net	1,942	265	5,843	$ 614
Total gain (loss)	3,486	1,428	$ (7,066)	$ (614)
Fair Value, Liability, Recurring Basis, Unobservable Input Reconciliation, Gain (Loss), Statement of Income or Comprehensive Income [Extensible Enumeration]			Revenue from Contract with Customer, Excluding Assessed Tax	Revenue from Contract with Customer, Excluding Assessed Tax
Change in unrealized gain (loss) included in earnings	5,428	1,693	$ (1,223)
Ending Balance	(5,606)	0	(5,606)	$ 0
Embedded derivatives
Reconciliation of the beginning and ending balances of liabilities measured at fair value using significant unobservable inputs (Level 3)
Beginning Balance	(32)	0		(556)
Settlements, net	0	0
Total gain (loss)	(21)	(87)	(53)	469
Change in unrealized gain (loss) included in earnings	(21)	(87)	(53)	469
Ending Balance	$ (53)	$ (87)	$ (53)	$ (87)

Other Receivables (Details)

Other Receivables (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Other Receivables
Other receivables	$ 35,112	$ 24,447
Loans to customers to finance vehicle purchases
Other Receivables
Other receivables	512	419
Accrued customer billings
Other Receivables
Other receivables	3,946	4,417
Fuel tax credits
Other Receivables
Other receivables	27,402	12,684
Other
Other Receivables
Other receivables	$ 3,252	$ 6,927

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Raw materials and spare parts	$ 35,927	$ 31,302
Total inventory	$ 35,927	$ 31,302

Land, Property and Equipment (D

Land, Property and Equipment (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Land, Property and Equipment
Land, property and equipment, gross	$ 696,817		$ 696,817		$ 693,689
Less accumulated depreciation	(447,915)		(447,915)		(431,928)
Total land, property and equipment, net	248,902		248,902		261,761
Capitalized software costs, net	35,000		35,000		33,800
Accumulated amortization on the capitalized software costs	31,700		31,700		30,400
Amortization expense related to the capitalized software costs	700	$ 300	1,300	$ 1,200
Amount included in accounts payable balances			2,900		2,100
Land
Land, Property and Equipment
Land, property and equipment, gross	3,476		3,476		3,476
LNG liquefaction plants
Land, Property and Equipment
Land, property and equipment, gross	94,633		94,633		94,633
Station equipment
Land, Property and Equipment
Land, property and equipment, gross	353,132		353,132		354,699
Trailers
Land, Property and Equipment
Land, property and equipment, gross	73,117		73,117		72,783
Other equipment
Land, Property and Equipment
Land, property and equipment, gross	95,799		95,799		93,135
Construction in progress
Land, Property and Equipment
Land, property and equipment, gross	$ 76,660		$ 76,660		$ 74,963

Land, Property and Equipment -

Land, Property and Equipment - Fueling Station Equipment Removal (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Property, Plant and Equipment [Abstract]
Accelerated depreciation expense	$ 8.1	$ 8.1
Incremental ARO charges	$ 0.7	$ 0.7

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Payables and Accruals [Abstract]
Accrued alternative fuels incentives	$ 30,948	$ 28,106
Accrued employee benefits	4,476	4,547
Accrued gas and equipment purchases	22,532	17,158
Accrued interest	1,685	893
Accrued property and other taxes	4,075	3,369
Accrued salaries and wages	6,687	8,172
Embedded derivatives	14	0
Other	14,783	12,914
Total accrued liabilities	$ 85,200	$ 75,159

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021
Principal Balances
Total debt	$ 28,663	$ 36,132
Less amounts due within one year	(4,198)	(12,868)
Total long-term debt	24,465	23,264
Unamortized Debt Financing Costs
Total debt	108	72
Less amounts due within one year	(33)	(23)
Total long-term debt	75	49
Balance, Net of Financing Costs
Total debt	28,555	36,060
Less amounts due within one year	(4,165)	(12,845)
Total long-term debt	24,390	23,215
NG Advantage debt
Principal Balances
Total debt	26,515	25,832
Unamortized Debt Financing Costs
Total debt	108	72
Balance, Net of Financing Costs
Total debt	26,407	25,760
SG Facility
Principal Balances
Total debt	2,000	9,500
Balance, Net of Financing Costs
Total debt	2,000	9,500
Other debt
Principal Balances
Total debt	148	800
Balance, Net of Financing Costs
Total debt	$ 148	$ 800

Debt - SG Credit and TOTAL Cred

Debt - SG Credit and TOTAL Credit Support Agreement (Details) - USD ($) $ in Thousands		3 Months Ended	9 Months Ended
	Jan. 02, 2019	Mar. 31, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Mar. 12, 2021
Long-term debt [Line Items]
Outstanding amount			$ 28,663		$ 36,132
Proceeds from revolving line of credit			0	$ 1,450
Term Loan Facility | Socit Gnrale
Long-term debt [Line Items]
Maximum borrowing capacity (up to)	$ 100,000
Commitment fee percentage	0.39%
Quarterly principal payments		$ 2,500
Covenant for debt default	$ 20,000
Outstanding amount			$ 2,000
Term Loan Facility | Socit Gnrale | London Interbank Offered Rate (LIBOR)
Long-term debt [Line Items]
Basis spread on variable rate	1.30%
Term Loan Facility | Socit Gnrale | Station Build Costs
Long-term debt [Line Items]
Maximum borrowing capacity (up to)						$ 45,000
Term Loan Facility | Socit Gnrale | ADG RNG Production Facilities
Long-term debt [Line Items]
Maximum borrowing capacity (up to)						$ 20,000
Term Loan Facility | Total Holdings USA Inc.
Long-term debt [Line Items]
Maximum borrowing capacity (up to)	$ 100,000
Interest rate per quarter	2.50%
Covenant for debt default	$ 20,000
Term Loan Facility | Total Holdings USA Inc. | London Interbank Offered Rate (LIBOR)
Long-term debt [Line Items]
Basis spread on variable rate	1%

Debt - NG Advantage Debt and Fi

Debt - NG Advantage Debt and Financing Lease Obligations (Details) $ in Thousands						3 Months Ended	9 Months Ended
	Jan. 31, 2022 USD ($)	Dec. 10, 2020 USD ($)	Dec. 20, 2018 USD ($)	Mar. 01, 2018 USD ($) installment	Dec. 18, 2017 USD ($) installment	Sep. 30, 2022 USD ($)	Sep. 30, 2022 USD ($)	Sep. 30, 2021 USD ($)	Dec. 31, 2021 USD ($)	Nov. 30, 2016 USD ($) installment
Long-term debt [Line Items]
Principal Balance						$ 28,663	$ 28,663		$ 36,132
Total restricted cash						0	0		7,008
Loss on extinguishment of debt						0	2,268	$ 25
Proceeds from revolving line of credit							0	1,450
Repayments of borrowing under revolving line of credit							0	$ 1,450
Held as collateral
Long-term debt [Line Items]
Total restricted cash	$ 7,000					0	0		7,008
Compression Station
Long-term debt [Line Items]
Purchase price			$ 7,000
Sale leaseback transaction, term			5 years
Annual rate (as a percent)			12%
Monthly rental payments			$ 100
Sale Leaseback Transaction, Security Deposit, Amount	800
Sale Leaseback Transaction, outstanding principal balance							0
BoA | BoA MLA
Long-term debt [Line Items]
Interest rate					4.86%
Principal Balance						100	100
Proceeds from sale of equipment in sale-leaseback agreement					$ 2,100
Sale leaseback transaction, term					5 years
Number of equal monthly installments | installment					60
First National | First National MLA
Long-term debt [Line Items]
Interest rate				9.28%
Proceeds from sale of equipment in sale-leaseback agreement				$ 6,300
Sale leaseback transaction, term				6 years
Number of equal monthly installments | installment				72
Sale Leaseback Transaction, outstanding principal balance							0
Loan and Security Agreement [Member] | 5.17% Term Loan | Wintrust Commercial Finance
Long-term debt [Line Items]
Debt issuance amount										$ 4,700
Number of monthly installments | installment										72
Interest rate										5.17%
Principal Balance						100	100
NG Advantage debt
Long-term debt [Line Items]
Principal Balance						26,515	26,515		25,832
NG Advantage debt | 5.0% Term Loan | Berkshire Bank
Long-term debt [Line Items]
Principal Balance						12,600	12,600
NG Advantage debt | 5% maturing on January 1, 2026 | Berkshire Bank
Long-term debt [Line Items]
Debt issuance amount	$ 14,000	$ 14,500
Interest rate	5%	5%
Principal Balance						13,700	13,700
Period during which the debt instrument principal balance is required to be paid following its issuance		5 years
NG Advantage debt | 5% maturing on January 1, 2026 | Berkshire Bank | Standby letters of credit
Long-term debt [Line Items]
Loan pledged as collateral									$ 7,000
NG Advantage debt | Revolving line of credit | Berkshire Bank
Long-term debt [Line Items]
Maximum borrowing capacity (up to)		$ 1,000
Outstanding line of credit						$ 0	$ 0
Interest rate during period (as a percent)		3%
NG Advantage debt | Revolving line of credit | Berkshire Bank | Prime Rate
Long-term debt [Line Items]
Basis spread on variable rate		0.25%

Debt - BP Loan and Plains Credi

Debt - BP Loan and Plains Credit Facility (Details) - Plains Credit Facility - USD ($) $ in Millions	Sep. 30, 2022	Jan. 31, 2022	Sep. 16, 2021	May 01, 2021
Revolving line of credit | Plains
Debt Instrument [Line Items]
Maximum borrowing capacity (up to)			$ 20	$ 20
Outstanding line of credit	$ 0
Remaining borrowing capacity	11		18
Revolving line of credit | Minimum | Plains
Debt Instrument [Line Items]
Interest rate (as a percent)				3.25%
Standby letters of credit | Plains
Debt Instrument [Line Items]
Maximum borrowing capacity (up to)			$ 2
Outstanding line of credit	$ 0
Standby letters of credit | Berkshire Bank
Debt Instrument [Line Items]
Loan pledged as collateral		$ 7

Debt - Other Debt (Details)

Debt - Other Debt (Details) - Other debt	Sep. 30, 2022	Dec. 31, 2021
Long-term debt [Line Items]
Weighted average interest rate	4.75%	4.34%
Maximum
Long-term debt [Line Items]
Interest rate	4.75%

Net Income (Loss) Per Share (De

Net Income (Loss) Per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Earnings Per Share [Abstract]
Net loss attributable to Clean Energy Fuels Corp.	$ (8,973)	$ (3,934)	$ (46,399)	$ (90,770)
Weighted-average common shares outstanding	222,239,376	223,008,202	222,409,802	209,771,584
Dilutive effect of potential common shares from restricted stock units and stock options	0	0	0	0
Weighted-average common shares outstanding - diluted	222,239,376	223,008,202	222,409,802	209,771,584
Basic loss per share (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.21)	$ (0.43)
Diluted loss per share (in dollars per share)	$ (0.04)	$ (0.02)	$ (0.21)	$ (0.43)

Net Income (Loss) Per Share - A

Net Income (Loss) Per Share - Anti-dilutive Securities (Details) - shares	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Net Loss Per Share
Anti-dilutive securities (in shares)	75,618,289	68,905,708	75,618,289	68,905,708
Stock options
Net Loss Per Share
Anti-dilutive securities (in shares)	16,170,384	8,896,688	16,170,384	8,896,688
Restricted stock units
Net Loss Per Share
Anti-dilutive securities (in shares)	680,191	1,241,306	680,191	1,241,306
Amazon warrant shares
Net Loss Per Share
Anti-dilutive securities (in shares)	58,767,714	58,767,714	58,767,714	58,767,714

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-based compensation expense, net of $0 tax in 2021 and 2022	$ 5,964	$ 3,435	$ 20,685	$ 10,220
Stock-based compensation expense, tax	0	$ 0	0	$ 0
Unrecognized compensation cost	30,900		$ 30,900
Unrecognized compensation cost, weighted-average period			1 year 6 months
Total unrecognized compensation cost related to non-vested shares	$ 4,700		$ 4,700

Stock-Based Compensation - Amaz

Stock-Based Compensation - Amazon Warrant (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021	Jun. 14, 2021	Apr. 16, 2021
Subsidiary, Sale of Stock [Line Items]
Common stock, par value (in dollars per share)	$ 0.0001		$ 0.0001		$ 0.0001
Contra revenue charge			$ 15,500	$ 80,237
Vesting over the first year | Transaction Agreement With Amazon
Subsidiary, Sale of Stock [Line Items]
Contra revenue charge		$ 76,600		76,600
Vesting over the second year | Transaction Agreement With Amazon
Subsidiary, Sale of Stock [Line Items]
Contra revenue charge		3,600		3,600
Amazon Warrant | Transaction Agreement With Amazon
Subsidiary, Sale of Stock [Line Items]
Aggregate number of warrant shares (in shares)						5,625,959	53,141,755
Total discretionary fuel purchases							$ 500,000
Exercise price of the warrant (in dollars per share)						$ 13.49	$ 13.49
Amazon Warrant | Prepaid expenses and other current assets
Subsidiary, Sale of Stock [Line Items]
Customer incentive assets	$ 26,700		26,700
Amazon Warrant | Vesting over the second year | Transaction Agreement With Amazon
Subsidiary, Sale of Stock [Line Items]
Contra revenue charge	$ 7,000	$ 2,200	$ 15,500	$ 80,200

Stock-Based Compensation - Am_2

Stock-Based Compensation - Amazon Warrant Activity (Details) - Amazon Warrant - USD ($)	3 Months Ended	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2022
Class of Warrant or Right [Line Items]
Outstanding and unvested as of December 31, 2021		$ 44,077,779
Granted		0
Vested	(587,704)	(1,175,408)
Outstanding and unvested as of September 30, 2022	$ 42,902,371	$ 42,902,371
Warrants, Vested, Number of Shares	587,704	1,175,408

Stockholders' Equity - Authoriz

Stockholders' Equity - Authorized Shares (Details) - shares	Sep. 30, 2022	Dec. 31, 2021	Jun. 14, 2021	Jun. 13, 2021
Stockholders' Equity Note [Abstract]
Authorized shares (in shares)	455,000,000		454,000,000	304,000,000
Common stock, authorized (in shares)	454,000,000	454,000,000
Preferred stock, authorized (in shares)	1,000,000	1,000,000

Stockholders' Equity - Share Re

Stockholders' Equity - Share Repurchase Program (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	31 Months Ended
	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2022	Sep. 30, 2022	Dec. 07, 2021	Mar. 12, 2020
Equity [Abstract]
Approved share repurchase program					$ 50,000	$ 30,000
Cost to repurchase common stock	$ 3,121	$ 3,001	$ 6,100
Repurchase of common stock (in shares)			1,190,254
Stock repurchase program total stock repurchased				9,387,340
Amount utilized under the repurchase plan				$ 23,500
Authorized funds remaining under the Repurchase Program			$ 26,500	$ 26,500

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Income Tax Disclosure [Abstract]
Income tax expense	$ 106	$ 60	$ 223	$ 199
Unrecognized tax benefits, increase from portion of AFTC revenue offset by the fuel tax			3,300
Alternative fuel tax credit	$ 25,300		$ 25,300

Commitments and Contingencies -

Commitments and Contingencies - bpJV Capital Call Contribution (Details) - bpJV - ADG RNG Production Facilities - USD ($) $ in Millions	1 Months Ended
	Jun. 30, 2021	Sep. 30, 2022	Mar. 30, 2022	Dec. 31, 2021	Jun. 21, 2021	Apr. 13, 2021
Other Commitments [Line Items]
Investment commitment in joint venture		$ 38.1			$ 50.2	$ 30
Initial contribution commitment	$ 30
bp
Other Commitments [Line Items]
Investment commitment in joint venture						$ 50
bpJV Capital Call
Other Commitments [Line Items]
Capital call contribution amount				$ 143.2
Investment commitment in joint venture		$ 51.6		71.6
bpJV Capital Call | bp
Other Commitments [Line Items]
Investment commitment in joint venture				$ 71.6
bpJV Capital Call 2
Other Commitments [Line Items]
Capital call contribution amount			$ 76.2
Investment commitment in joint venture			38.1
bpJV Capital Call 2 | bp
Other Commitments [Line Items]
Investment commitment in joint venture			$ 38.1

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Leases
Sales-type lease, interest income	$ 0.1	$ 0.1	$ 0.3	$ 0.3

Leases - Maturities of Lease Re

Leases - Maturities of Lease Receivables (Details) $ in Thousands	Sep. 30, 2022 USD ($)
Fiscal year:
Remainder of 2022	$ 240
2023	962
2024	962
2025	962
2026	985
Thereafter	2,374
Total minimum lease payments	6,485
Less amount representing interest	(1,588)
Present value of lease receivables	$ 4,897

Alternative Fuel Excise Tax Cre

Alternative Fuel Excise Tax Credit (Details) - $ / gal		12 Months Ended
	Jan. 01, 2022	Dec. 31, 2021	Dec. 31, 2020
Alternative Fuel Excise Tax Credit
Federal alternative fuels tax credit - CNG (in dollars per gasoline gallon equivalent)	0.50	0.50	0.50
Federal alternative fuels tax credit - LNG (in dollars per liquid gallon)	0.50	0.50	0.50

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
TOTALEnergies S.E.
Related Party Transaction [Line Items]
Proceeds from related party	$ 2.8	$ 1.6	$ 5.7	$ 3.1
Receivables from related party	2.6		2.6		$ 1.4
Related party expense	2.5	0.4	6.1	1.3
Payable to related parties					0.1
SAFE&CEC S.r.l.
Related Party Transaction [Line Items]
Proceeds from related party		0	0.2	0.2
Receivables from related party	0.1		0.1
Related party expense	2.8	$ 3.3	8.5	$ 5.8
Payable to related parties	0.7		0.7		0.2
TotalEnergies JV and bpJV
Related Party Transaction [Line Items]
Proceeds from related party	0.3		0.9
Receivables from related party	$ 0.3		$ 0.3		$ 0.4