Table of Contents

 
UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, DC 20549
FORM 10-Q
QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF
THE SECURITIES EXCHANGE ACT OF 1934
For the quarterly period ended September 30, 20162017
Commission File Number: 001-33480
CLEAN ENERGY FUELS CORP.
(Exact name of registrant as specified in its charter)
Delaware 33-0968580
(State or other jurisdiction of incorporation) (IRS Employer Identification No.)
4675 MacArthur Court, Suite 800, Newport Beach, CA 92660
(Address of principal executive offices, including zip code)
(949) 437-1000
(Registrant’s telephone number, including area code)
Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No o
Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232,405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files). Yes x No o
Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or a smaller reporting company. See definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” and "emerging growth company" in Rule 12b-2 of the Exchange Act. (Check one):
Large accelerated filer o
 
Accelerated filer x
   
Non-accelerated filer o
(Do not check if a smaller reporting company)
 
Smaller reporting company o
Emerging growth company o
If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. o
Indicate by check mark whether the registrant is a shell company (as defined by Rule 12b-2 of the Act). Yes o No x
As of October 27, 2016,26, 2017, there were 136,840,598151,085,558 shares of the registrant’s common stock, par value $0.0001 per share, issued and outstanding.
 

CLEAN ENERGY FUELS CORP. AND SUBSIDIARIES
INDEX
Table of Contents
 
  
 

PART I.—FINANCIAL INFORMATION
Item 1.—Financial Statements (Unaudited)
Clean Energy Fuels Corp. and Subsidiaries
Condensed Consolidated Balance Sheets
(In thousands, except share data, Unaudited)

December 31,
2015
 September 30,
2016
December 31,
2016
 September 30,
2017
Assets      
Current assets:      
Cash and cash equivalents$43,724
 $41,555
$36,119
 $45,312
Restricted cash4,240
 4,629
6,996
 1,463
Short-term investments102,944
 77,313
73,718
 151,521
Accounts receivable, net of allowance for doubtful accounts of $1,895 and $2,343 as of December 31, 2015 and September 30, 2016, respectively73,645
 72,949
Accounts receivable, net of allowance for doubtful accounts of $1,063 and $2,336 as of December 31, 2016 and September 30, 2017, respectively79,432
 61,001
Other receivables60,667
 28,564
21,934
 16,253
Inventory29,289
 29,455
29,544
 44,624
Prepaid expenses and other current assets14,657
 15,191
14,021
 10,838
Total current assets329,166
 269,656
261,764
 331,012
Land, property and equipment, net516,324
 487,922
483,923
 363,773
Notes receivable and other long-term assets, net14,732
 16,981
16,377
 25,619
Investments in other entities5,695
 2,644
3,475
 2,542
Goodwill91,967
 93,848
93,018
 68,082
Intangible assets, net42,644
 40,303
38,700
 7,491
Total assets$1,000,528
 $911,354
$897,257
 $798,519
Liabilities and Stockholders’ Equity      
Current liabilities:      
Current portion of debt and capital lease obligations$149,856
 $4,851
$5,943
 $29,247
Accounts payable26,906
 23,106
23,637
 16,215
Accrued liabilities59,082
 54,267
52,601
 41,990
Deferred revenue10,549
 8,544
7,041
 6,487
Total current liabilities246,393
 90,768
89,222
 93,939
Long-term portion of debt and capital lease obligations352,294
 282,769
241,433
 185,597
Long-term debt, related party65,000
 65,000
65,000
 40,000
Other long-term liabilities7,896
 8,168
7,915
 13,416
Total liabilities671,583
 446,705
403,570
 332,952
Commitments and contingencies

 



 

Stockholders’ equity:      
Preferred stock, $0.0001 par value. Authorized 1,000,000 shares; issued and outstanding no shares
 

 
Common stock, $0.0001 par value. Authorized 224,000,000 shares; issued and outstanding 92,382,717 shares and 134,235,058 shares at December 31, 2015 and September 30, 2016, respectively
9
 13
Common stock, $0.0001 par value. Authorized 224,000,000 shares; issued and outstanding 145,538,063 shares and 151,009,700 shares at December 31, 2016 and September 30, 2017, respectively
15
 15
Additional paid-in capital915,199
 1,055,211
1,090,361
 1,110,158
Accumulated deficit(591,683) (599,953)(603,836) (655,223)
Accumulated other comprehensive loss(20,973) (15,698)(17,675) (12,392)
Total Clean Energy Fuels Corp. stockholders’ equity302,552
 439,573
468,865
 442,558
Noncontrolling interest in subsidiary26,393
 25,076
24,822
 23,009
Total stockholders’ equity328,945
 464,649
493,687
 465,567
Total liabilities and stockholders’ equity$1,000,528
 $911,354
$897,257
 $798,519
See accompanying notes to condensed consolidated financial statements.

Clean Energy Fuels Corp. and Subsidiaries
Condensed Consolidated Statements of Operations
(In thousands, except share and per share data, Unaudited)
Three Months Ended
September 30,
 Nine Months Ended
September 30,
 Three Months Ended
September 30,
 Nine Months Ended
September 30,
 
2015 2016 2015 2016 2016 2017 2016 2017 
Revenue:                
Product revenues$77,355
 $84,456
 $222,396
 $263,179
 
Service revenues14,902
 12,561
 42,577
 37,645
 
Total revenues92,257
 97,017
 264,973
 300,824
 
Product revenue$84,456
 $67,669
 $263,179
 $211,747
 
Service revenue12,561
 14,123
 37,645
 40,552
 
Total revenue97,017
 81,792
 300,824
 252,299
 
Operating expenses:                
Cost of sales (exclusive of depreciation and amortization shown separately below):                
Product cost of sales59,313
 55,481
 174,079
 170,746
 55,481
 52,884
 170,746
 158,306
 
Service cost of sales7,410
 6,377
 21,163
 19,095
 6,377
 7,283
 19,095
 20,066
 
Gain from change in fair value of derivative warrants(502) (26) (1,085) (25) 
Inventory valuation provision
 13,158
 
 13,158
 
Selling, general and administrative27,800
 25,914
 87,027
 76,769
 25,888
 24,798
 76,744
 71,875
 
Depreciation and amortization14,000
 14,801
 40,288
 44,682
 14,801
 14,104
 44,682
 43,757
 
Asset impairments and other charges
 60,666
 
 60,666
 
Total operating expenses108,021
 102,547
 321,472
 311,267
 102,547
 172,893
 311,267
 367,828
 
Operating loss(15,764) (5,530) (56,499) (10,443) (5,530) (91,101) (10,443) (115,529) 
Gain (loss) from extinguishment of debt, net
 (668) 
 25,375
 
Interest expense, net(10,152) (6,283) (30,020) (23,264) 
Interest expense(6,406) (4,270) (23,843) (13,466) 
Interest income123
 465
 579
 1,156
 
Other income (expense), net2,648
 (109) 3,512
 (6) (109) 4
 (6) (28) 
Loss from equity method investments(154) (13) (703) (20) (13) (30) (20) (100) 
Gain (loss) from extinguishment of debt(668) 
 25,375
 3,195
 
Gain from sale of certain assets of subsidiary
 
 
 69,886
 
Loss before income taxes(23,422) (12,603) (83,710) (8,358) (12,603) (94,932) (8,358) (54,886) 
Income tax benefit (expense)241
 (416) (1,353) (1,229) (416) 44
 (1,229) 2,183
 
Net loss(23,181) (13,019) (85,063) (9,587) (13,019) (94,888) (9,587) (52,703) 
Loss from noncontrolling interest62
 391
 835
 1,317
 
Loss attributable to noncontrolling interest391
 747
 1,317
 1,813
 
Net loss attributable to Clean Energy Fuels Corp.$(23,119) $(12,628) $(84,228) $(8,270) $(12,628) $(94,141) $(8,270) $(50,890) 
Loss per share attributable to Clean Energy Fuels Corp.:        
Loss per share:        
Basic$(0.25) $(0.10) $(0.92) $(0.07) $(0.10) $(0.62) $(0.07) $(0.34) 
Diluted$(0.25) $(0.10) $(0.92) $(0.07) $(0.10) $(0.62) $(0.07) $(0.34) 
Weighted-average common shares outstanding:                
Basic91,561,613
 130,436,038
 91,454,117
 112,819,041
 130,436,038
 150,927,825
 112,819,041
 150,128,204
 
Diluted91,561,613
 130,436,038
 91,454,117
 112,819,041
 130,436,038
 150,927,825
 112,819,041
 150,128,204
 
See accompanying notes to condensed consolidated financial statements.

Clean Energy Fuels Corp. and Subsidiaries
Condensed Consolidated Statements of Comprehensive Loss
(In thousands, Unaudited)
Clean Energy Fuels Corp. Noncontrolling Interest TotalClean Energy Fuels Corp. Noncontrolling Interest Total
Three Months Ended
September 30,
 Three Months Ended
September 30,
 Three Months Ended
September 30,
Three Months Ended
September 30,
 Three Months Ended
September 30,
 Three Months Ended
September 30,
2015 2016 2015 2016 2015 20162016 2017 2016 2017 2016 2017
Net loss$(23,119) $(12,628) $(62) $(391) $(23,181) $(13,019)$(12,628) $(94,141) $(391) $(747) $(13,019) $(94,888)
                      
Other comprehensive income (loss), net of tax:                      
Foreign currency translation adjustments, net of $0 tax in 2015 and 2016(1,230) (449) 
 
 (1,230) (449)
Foreign currency adjustments on intra-entity long-term investments, net of $0 tax in 2015 and 2016(5,597) (885) 
 
 (5,597) (885)
Unrealized gains (losses) on available-for-sale securities, net of $0 tax in 2015 and 201627
 (11) 
 
 27
 (11)
Foreign currency translation adjustments, net of $0 tax in 2016 and 2017(449) 252
 
 
 (449) 252
Foreign currency adjustments on intra-entity long-term investments, net of $0 tax in 2016 and 2017(885) 2,919
 
 
 (885) 2,919
Unrealized gains (losses) on available-for-sale securities, net of $0 tax in 2016 and 2017(11) 70
 
 
 (11) 70
Total other comprehensive income (loss)(6,800) (1,345) 
 
 (6,800) (1,345)(1,345) 3,241
 
 
 (1,345) 3,241
Comprehensive loss$(29,919) $(13,973) $(62) $(391) $(29,981) $(14,364)$(13,973) $(90,900) $(391) $(747) $(14,364) $(91,647)
Clean Energy Fuels Corp. Noncontrolling Interest TotalClean Energy Fuels Corp. Noncontrolling Interest Total
Nine Months Ended
September 30,
 Nine Months Ended
September 30,
 Nine Months Ended
September 30,
Nine Months Ended
September 30,
 Nine Months Ended
September 30,
 Nine Months Ended
September 30,
2015 2016 2015 2016 2015 20162016 2017 2016 2017 2016 2017
Net loss$(84,228) $(8,270) $(835) $(1,317) $(85,063) $(9,587)$(8,270) $(50,890) $(1,317) $(1,813) $(9,587) $(52,703)
                      
Other comprehensive income (loss), net of tax:                      
Foreign currency translation adjustments, net of $0 tax in 2015 and 2016(6,098) 2,185
 
 
 (6,098) 2,185
Foreign currency adjustments on intra-entity long-term investments, net of $0 tax in 2015 and 2016(8,373) 3,024
 
 
 (8,373) 3,024
Unrealized gains (losses) on available-for-sale securities, net of $0 tax in 2015 and 201641
 66
 
 
 41
 66
Foreign currency translation adjustments, net of $0 tax in 2016 and 20172,185
 289
 
 
 2,185
 289
Foreign currency adjustments on intra-entity long-term investments, net of $0 tax in 2016 and 20173,024
 5,033
 
 
 3,024
 5,033
Unrealized gains (losses) on available-for-sale securities, net of $0 tax in 2016 and 201766
 (39) 
 
 66
 (39)
Total other comprehensive income (loss)(14,430) 5,275
 
 
 (14,430) 5,275
5,275
 5,283
 
 
 5,275
 5,283
Comprehensive loss$(98,658) $(2,995) $(835) $(1,317) $(99,493) $(4,312)$(2,995) $(45,607) $(1,317) $(1,813) $(4,312) $(47,420)
See accompanying notes to condensed consolidated financial statements.

Clean Energy Fuels Corp. and Subsidiaries
Condensed Consolidated Statements of Cash Flows
(In thousands, Unaudited)
 Nine Months Ended
September 30,
 2016 2017
Cash flows from operating activities:   
Net loss$(9,587) $(52,703)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:   
Depreciation and amortization44,682
 43,757
Provision for doubtful accounts, notes and inventory2,504
 16,156
Stock-based compensation expense6,533
 6,604
Amortization of debt issuance cost1,217
 647
Gain on extinguishment of debt(25,375) (3,195)
Gain from sale of certain assets of subsidiary
 (69,886)
Non-cash portion of asset impairments and other charges
 58,119
Changes in operating assets and liabilities:   
Accounts and other receivables31,134
 23,936
Inventory(1,043) 494
Prepaid expenses and other assets(178) 794
Accounts payable(940) (9,426)
Accrued expenses and other(4,702) (20,148)
Net cash provided by (used in) operating activities44,245
 (4,851)
Cash flows from investing activities:   
Purchases of short-term investments(88,660) (227,212)
Maturities and sales of short-term investments113,852
 149,044
Purchases and deposits on property and equipment(16,663) (27,529)
Loans made to customers(2,326) (535)
Payments on and proceeds from sales of loans receivable575
 978
Restricted cash(267) 1,578
Cash received from sale of certain assets of subsidiary, net of cash transferred
 154,489
Investments in other entities
 (1,929)
Capital from equity method investment3,031
 
Nonrefundable customer deposit
 8,350
Net cash provided by investing activities9,542
 57,234
Cash flows from financing activities:   
Issuances of common stock68,867
 10,767
Fees paid for issuances of common stock(1,340) (638)
Payment to holders of stock options in subsidiary
 (8,605)
Proceeds from debt instruments2,460
 7,561
Proceeds from revolving line of credit50,008
 308
Repayment of borrowing under revolving line of credit(50,014) (23,670)
Repayment of capital lease obligations and debt instruments(127,213) (29,664)
Net cash used in financing activities(57,232) (43,941)
Effect of exchange rates on cash and cash equivalents1,276
 751
Net increase in cash and cash equivalents(2,169) 9,193
Cash and cash equivalents, beginning of period43,724
 36,119
Cash and cash equivalents, end of period$41,555
 $45,312
Supplemental disclosure of cash flow information:   
Income taxes paid$1,176
 $363
Interest paid, net of approximately $712 and $73 capitalized, respectively21,275
 14,351
 Nine Months Ended
September 30,
 2015 2016
Cash flows from operating activities:   
Net loss$(85,063) $(9,587)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:   
Depreciation and amortization40,288
 44,682
Provision for doubtful accounts, notes and inventory2,636
 2,504
Stock-based compensation expense8,009
 6,533
Gain on extinguishment of debt, net
 (25,375)
Amortization of debt issuance cost2,296
 1,217
Accretion of notes payable48
 
Gain on sale of subsidiary(937) 
Changes in operating assets and liabilities:   
Accounts and other receivables41,151
 31,134
Inventory3,915
 (1,043)
Prepaid expenses and other assets6,763
 (178)
Accounts payable(11,325) (940)
Accrued expenses and other(8,792) (4,702)
Net cash provided by (used in) operating activities(1,011) 44,245
Cash flows from investing activities:   
Purchases of short-term investments(101,300) (88,660)
Maturities and sales of short-term investments108,561
 113,852
Purchases and deposits on property and equipment(40,230) (16,663)
Loans made to customers(3,885) (2,326)
Payments on and proceeds from sales of loans receivable997
 575
Cash received with sale of subsidiary1,118
 
Restricted cash2,141
 (267)
Capital from equity method investment
 3,031
Net cash provided by (used in) investing activities(32,598) 9,542
Cash flows from financing activities:   
Issuances of common stock
602
 68,867
Fees paid for issuances of common stock
(795) (1,340)
Proceeds from debt instruments372
 2,460
Proceeds from revolving line of credit27
 50,008
Repayment of borrowing under revolving line of credit(62) (50,014)
Repayment of capital lease obligations and debt instruments(4,425) (127,213)
Net cash used in financing activities(4,281) (57,232)
Effect of exchange rates on cash and cash equivalents(2,648) 1,276
Net decrease in cash and cash equivalents(40,538) (2,169)
Cash and cash equivalents, beginning of period92,381
 43,724
Cash and cash equivalents, end of period$51,843
 $41,555
Supplemental disclosure of cash flow information:   
Income taxes paid$649
 $1,176
Interest paid, net of approximately $712 and $363 capitalized, respectively24,425
 21,275
See accompanying notes to condensed consolidated financial statements.

Clean Energy Fuels Corp. and Subsidiaries
Notes to Condensed Consolidated Financial Statements
(In thousands, except share and per share data, Unaudited)
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,”"Company," unless the context or the use of the term indicates or requires otherwise), is engaged in the business of selling natural gas as an alternative fuel for vehicle fleets and related natural gas fueling solutions to its customers, primarily in the United States and Canada.
The Company's principal business is supplying renewable natural gas ("RNG"), compressed natural gas (“CNG”), and liquefied natural gas (“LNG”) and renewable natural gas that can be delivered in the form of CNG or LNG ("RNG") for light, medium and heavy-duty vehicles and providing operation and maintenance ("O&M") services for natural gas fueling stations. As a comprehensive solution provider, the Company also designs, builds, operates, and maintains fueling stations; manufactures, sells and services non-lubricated natural gas fueling compressors and other equipment used in CNG stations and LNG stations; offers assessment, design and modification solutions to provide operators with code-compliant service and maintenance facilities for natural gas vehicle fleets; transports and sells CNG and LNG to industrial and institutional energy users who do not have direct access to natural gas pipelines; processesprocures and sells RNG; sells tradable credits it generates by selling natural gas and RNG as a vehicle fuel, including credits under the California and the Oregon Low Carbon Fuel Standards (collectively, "LCFS Credits") and Renewable Identification Numbers ("RIN Credits" or "RINs") under the federal Renewable Fuel Standard Phase 2; helps its customers acquire and finance natural gas vehicles; 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 financial position, results of operations, comprehensive loss and cash flows as of and for the three and nine months ended September 30, 20152016 and 2016.2017. All intercompany accounts and transactions have been eliminated in consolidation. The three and nine month periods ended September 30, 20152016 and 20162017 are not necessarily indicative of the results to be expected for the year ending December 31, 20162017 or for any other interim period or for any future year.
Certain information and disclosures normally included in the notes to the 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 (“US GAAP”) as they apply to interim reporting. The condensed consolidated financial statements should be read in conjunction with the consolidated financial statements as of and for the year ended December 31, 20152016 that are included in the Company’s Annual Report on Form 10-K filed with the SEC on March 3, 2016.7, 2017.
Reclassifications Certain prior period items and amounts, including certain line items in accrued liabilities in Note 9 and in the condensed consolidated statementstatements of cash flows,operations have been reclassified to conform to the classifications used to prepare the condensed consolidated financial statements for the period ended September 30, 2016.2017. These reclassifications had no material impact on the Company’s financial position, results of operations, or cash flows as previously reported.

During the three months ended March 31, 2016, the Company adopted Accounting Standards Update ("ASU") No. 2015-03, Interest - Imputation of Interest, which requires that debt issuance costs be presented in the balance sheet as a deduction from the carrying amount of the related liability, rather than as a deferred charge. The standard is required to be applied on a retrospective basis. As a result of applying the standard, unamortized debt issuance costs of $273 were reclassified from Prepaid expenses and other current assets to Current portion of long-term debt and capital lease obligations and $4,991 were reclassified from Notes receivable and other long-term assets to Long-term debt and capital lease obligations as of December 31, 2015.

Use of Estimates The preparation of condensed consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the the amounts reported in the accompanying unaudited condensed consolidated financial statements and accompanyingthese notes. Actual results could differ from those estimates and may result in material effects on the Company’s operating results and financial position.
Revenue Recognition Beginning January 1, 2016,
Note 2—Asset Impairments, Other Charges, and Inventory Valuation Provision
In light of continuing low oil prices and the Company began using the percentagecurrent state of completion method to recognize revenue for station construction projects using the cost-to-cost method. Under this method, the Company estimates the percentage of completion of a project based on the costs incurred to date for the associated contract in comparison to the estimated total costs for such contract at completion. Historically, the Company recognized revenue on station construction projects using the completed-contract method because it did not have a reliable means to make estimates of the percentage of the contract

completed. Under the completed contract method, the construction projects were considered substantially complete at the earlier of customer acceptance of the fueling station or the time when fuel dispensing activities at the station began. The sale of compressors and related equipment continues to be recognized under the percentage of completion method as in previous periods.     

Effective January 1, 2016, the Company implemented a cost tracking system that provides for a detailed tracking of costs incurred on its station construction projects on a project by project basis. The Company also changed related accounting activities and processes to timely identify and monitor costs. As a result of this implementation, the Company is able to make reliable estimates as to the percentage of a project that is complete at the end of each reporting period.

Station construction contracts are generally short-term, except for certain larger and more complex stations, which can take up to 24 months to complete. Management evaluates the performance of contracts on an individual contract basis. Contract price and cost estimates are reviewed periodically as work progresses and adjustments proportionate to the percentage of completion are reflected in contract revenues in the reporting period when such estimates are revised.

The nature of accounting for contracts is such that refinements of estimates to account for changing conditions and new developments are continuous and characteristic of the process. Many factors that can affect contract profitability may change during the performance period of a contract, including differing site conditions, the availability of skilled contract labor, the performance of major suppliers and subcontractors, and unexpected changes in material costs. Changes to these factors may result in revisions to costs and income, which are recognized in the period in which the revisions become known. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses become known. During the nine months ended September 30, 2016, there were no significant losses on open contracts.

The Company considers unapproved change orders to be contract variations for which the customer has approved the change of scope but an agreement has not been reached as to an associated price change. Change orders that are unapproved as to both price and scope are evaluated as claims. Claims have historically been insignificant. There were no significant unapproved change orders, claims, contract penalties, settlements or changes in contract estimates during the nine months ended September 30, 2016.

As a result of using the percentage of completion method to recognize revenues, revenue and operating income from station construction salesnatural gas vehicle adoption, during the three months ended September 30, 2016 were lower by $3,764 and $310, respectively, than would have been recognized during the period under the completed contract method. There was no impact on the income per diluted share. During the nine months ended September 30, 2016, revenue and operating income from station construction sales were higher by $14,083 and $1,864, respectively, than would have been recognized during the period under the completed contract method. Income per diluted share was $0.02 higher than what would have been reported.
Note 2— Investments in Other Entities and Noncontrolling Interest in a Subsidiary
MCEP
On September 16, 2014,2017, the Company formedundertook an evaluation of its operations with the intent of minimizing and eliminating assets it believes are underperforming. As a joint venture with Mansfield Ventures LLC (“Mansfield”) called Mansfield Clean Energy Partners LLC (“MCEP”), which is designed to provideresult of this evaluation, the Company identified certain of its fueling stations where the current and projected natural gas fueling solutionsvolume and profitability levels are not expected to bulk fuel haulersbe sufficient to support the Company’s investment in the United States.fueling station assets, and the Company decided to close these stations by the end of 2017. The Company also reduced its workforce and Mansfield each have a 50% ownership interesttook other steps to reduce overhead costs in MCEP. The Company accounts for its interest using the equity method of accounting, as the Company has the ability to exercise significant influence over MCEP’s operations. The Company recorded a loss from this investment of $154 and $13 for the three months ended September 30, 20152017 as a result of this evaluation, in an effort to lower its operating expenses going forward. In addition, this evaluation resulted in a strategic shift in how the Company viewed its natural gas compressor business, Clean Energy Compression Corp. ("CECC").The Company determined to seek a strategic partner for CECC and 2016, respectively. to position CECC to benefit from consolidation in the natural gas compressor sector, in an effort to increase CECC’s scale and reach and improve the financial prospects of the Company’s investment in CECC. As a result of these decisions and the steps taken to implement them, the Company incurred

, on a pre-tax basis, aggregate cash and non-cash charges of $60,666 related to asset impairments and other charges in addition to a $13,158 non-cash inventory valuation charge (see Note 9 for more information), during the three and nine months ended September 30, 2017.

The following table summarizes these charges:
 Three and Nine Months Ended
September 30, 2017
Workforce reduction and related charges$3,057
CECC asset impairments32,274
Station closures and related charges25,335
Total asset impairments and other charges$60,666
Inventory valuation provision13,158
Total charges$73,824

Workforce Reduction and Related Charges

As a result of the workforce reduction, severance of $2,757 was incurred for terminated employees and $300 in stock-based compensation expense was incurred for the acceleration of certain stock options and awards.

Impairments of Long-Lived Assets

The Company reviews the carrying value of its long-lived assets, including intangible assets with finite useful lives, for impairment whenever events or changes in circumstances indicate that the carrying value of an asset or asset group may not be recoverable. Events that could result in an impairment review include, among others, a significant decrease in the operating performance of a long-lived asset or the decision to close a fueling station. Impairment testing involves a comparison of the sum of the undiscounted future cash flows of the asset or asset group to its carrying amount. If the sum of the undiscounted future cash flows exceeds the carrying amount, then no impairment exists. If the carrying amount exceeds the sum of the undiscounted future cash flows, then a second step is performed to determine the amount of impairment, if any, to be recognized. An impairment loss is recognized to the extent that the carrying amount of the asset or asset group exceeds its fair value. The fair value of the asset or asset group is based on estimated discounted future cash flows of the asset or asset group using a discount rate commensurate with the related risk. The estimate of future cash flows requires management to make assumptions and to apply judgment, including forecasting future sales and expenses and estimating useful lives of the assets. These estimates can be affected by a number of factors, including, among others, future results, demand, and economic conditions, many of which can be difficult to predict.

CECC: Asset Impairment Charges

Due to the continued low global demand for compressors, and the decision to seek a strategic partner for CECC, the Company’s management determined that an impairment indicator was present for the long-lived assets of CECC. Recoverability was tested using future cash flow projections based on management’s long-term estimates of market conditions. Based on the results of this test, the sum of the undiscounted future cash flows was less than the carrying value of the CECC asset group. As a result, these long-lived assets were written down to their respective fair values, resulting in an impairment charge of $32,274. Fair value was based on expected future cash flows using Level 3 inputs under the Financial Accounting Standards Board’s (“FASB”) Accounting Standard Codification (“ASC”) Topic 820. The cash flows are those expected to be generated by market participants, discounted at an appropriate rate for the risks inherent in those cash flow projections. If actual results, market and economic conditions, including interest rates, and other factors are not consistent with management’s estimates and assumptions used in these calculations, the Company may be exposed to additional impairment losses.

The following table represents intangible assets of CECC as of December 31, 2016 and September 30, 2017, respectively, as well as their useful lives, which continued to be appropriate and were not changed:
  December 31,
2016
 September 30,
2017
 Remaining Useful Life (Years)
Technology $29,060
 $3,151
 13
Customer relationships 2,239
 117
 1
Trademark and trade names 1,842
 201
 3
Total $33,141
 $3,469
  

Station Closures and Related Charges

In the three months ended September 30, 2017, the Company decided to close 42 fueling stations by December 31, 2017 which are performing below management’s expectations based on volume and profitability levels. As a result, these station assets, which had an aggregate carrying value of $23,270 were written down to their respective fair values of $2,886 on an aggregate basis, resulting in charges of $20,384. The fair values of these assets were determined using the cost approach.

Due to these stations being closed before their initially intended date the Company's management assessed whether impairment indicators were present for the long-lived assets of the remaining stations. The Company determined there were no indicators of impairment present amongst the remaining stations and no further steps were required for evaluation.

In addition, certain of these station closures triggered related other charges totaling $4,951, which consists of write-offs for any deferred losses, lease termination fees, and an increase in asset retirement obligations ("AROs").
Inventory Valuation Provision
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 market. The Company writes down the carrying value of its inventory to net realizable value for estimated obsolescence or unmarketable inventory in an amount equal to the difference between the cost of inventory and its estimated realizable value based upon assumptions about future demand and market conditions, among other factors.
As a result of the Company's valuation process to minimize and eliminate under-performing station assets, the Company determined that $27,198 of certain station parts which historically were classified as construction in progress within Land, property, and equipment, net in the condensed consolidated balance sheets, are now reported as Inventory as they will primarily be used for stations to be sold. Subsequently, the Company determined a lower of cost or market non-cash charge of $7,804 for these station parts. Additionally, in conjunction with its decision to seek a strategic partner for CECC, the Company incurred a lower of cost or market non-cash charge of $5,354 for the inventory of CECC. The aggregate amount of $13,158 is reported as Inventory valuation provision in the condensed consolidated statements of operations during the three and nine months ended September 30, 2017.

Cash Related Charges

The following table summarizes the total charges that will be settled with cash payments and their related liability balances as of September 30, 2017:
  Charges Cash Payments Made in the Three Months Ended September 30, 2017Balance as of September 30, 2017
Employee severance $2,757
 $(2,547)$210
Lease termination fees and AROs for station closures 3,861
 
3,861
  $6,618
  $4,071

Goodwill
As a result of the asset impairments described above, the Company determined that sufficient indicators of potential impairment existed to require an interim goodwill test of its one reporting unit prior to the annual test performed in the fourth quarter of 2017. The goodwill test is performed by computing the fair value of the reporting unit and comparing it to the carrying value.

Based on the results of this test, the Company has determined that it continues to be a single reporting unit and, based upon step one of the two-step goodwill test, has concluded it is more likely than not that the fair value of its reporting unit exceeds its carrying amount and thus no further quantitative analysis was warranted.

Note 3—Acquisitions and Divestitures
On February 27, 2017, Clean Energy Renewable Fuels ("Renewables"), a subsidiary of the Company, entered into an asset purchase agreement (the “APA”) with BP Products North America, Inc. (“BP”), pursuant to which Renewables agreed to sell to BP certain assets relating to its RNG production business (the “Asset Sale”), consisting of Renewables’ two existing RNG production facilities, Renewables’ interest in the RNG Ventures (as defined in Note 11) and Renewables’ third-party RNG supply

contracts (the “Assets”). The Asset Sale was completed on March 31, 2017 for a sale price of $155,511, plus BP assumed the obligations under the Canton Bonds (as defined in Note 13), which totaled $8,820 as of March 31, 2017.

On March 31, 2017 BP paid Renewables $30,000 in cash and delivered to Renewables a promissory note with a principal amount of $123,487 (the "BP Note") which was paid in full on April 3, 2017. In addition, as a result of the determination of certain post-closing adjustments, (i) BP paid Renewables an additional $2,010 on June 22, 2017, and (ii) the gain recorded from the Asset Sale was reduced by $762. Pursuant to the APA, the valuation date of the Asset Sale was January 1, 2017, and as a lossresult, the APA included certain adjustments to the purchase price to reflect a determination of the amount of cash accumulated by Renewables from this investmentthe valuation date to the closing date, net of $703permitted cash outflows. Control of the Assets was not transferred until the Asset Sale was completed on March 31, 2017. Accordingly, the full operating results of Renewables are included in the condensed consolidated statement of operations through the three months ended March 31, 2017.

In addition, under the APA, BP is required, following the closing of the Asset Sale, to pay Renewables up to an additional $25,000 in cash over a five-year period if certain performance criteria relating to the Assets are met.

The Company incurred $3,695 in transaction fees in connection with the Asset Sale, and $20subsequent to March 31, 2017, the Company paid $8,605 in cash and issued 770,269 shares of the Company's common stock, collectively valued at $1,964, to holders of options to purchase membership units in Renewables. The net proceeds from the Asset Sale, net of $1,007 cash transferred to BP, were $142,190.

Following completion of the Asset Sale, Renewables and the Company are continuing to procure RNG from BP under a long-term supply contract and from other RNG suppliers, and resell such RNG through the Company's natural gas fueling infrastructure as Redeem™, the Company's RNG vehicle fuel. The Company also collects royalties from BP on gas purchased from BP and sold as Redeem™ at the Company's stations, which royalty is in addition to any payment obligation of BP under the APA.
The Asset Sale resulted in a total gain of $69,886 that was recorded in gain from sale of certain assets of subsidiary in the Company's condensed consolidated statement of operations for the nine months ended September 30, 2015 and 2016, respectively. Additionally, during the nine months ended September 30, 2016, the Company received a return of capital of $3,031 with no change in ownership interest. The Company has an investment balance of $4,695 and $1,644 at December 31, 2015 and September 30, 2016, respectively.
NG Advantage
On October 14, 2014, the Company entered into a Common Unit Purchase Agreement (“UPA”) with NG Advantage, LLC (“NG Advantage”) for a 53.3% controlling interest in NG Advantage. NG Advantage is engaged2017. Included in the businessdetermination of transporting CNG in high-capacity trailersthe total gain is goodwill of $26,576 that was allocated to large industrialthe disposed assets based on the relative fair values of the assets disposed and institutional energy users, such as hospitals, food processors, manufacturers and paper mills,the portion of the reporting unit that do not have direct access to natural gas pipelines.was retained.
The Company vieweddetermined that the acquisition asAsset Sale did not meet the definition of a discontinued operation because the disposal did not represent a significant disposal nor was the disposal a strategic investmentshift in the expansion of the Company’s initiative to deliver natural gas to industrial and institutional energy users. The results of NG Advantage’s operations have been included in the Company’s consolidated financial statements since October 14, 2014.

The Company recorded a loss from the noncontrolling interest of $62 and $391 for the three months ended September 30, 2015 and 2016, respectively and $835 and $1,317 for the nine months ended September 30, 2015 and 2016, respectively. The noncontrolling interest was $26,393 and $25,076 at December 31, 2015 and September 30, 2016, respectively.Company's strategy.
Note 3—4—Cash and Cash Equivalents
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 investments may be in excess of the Federal Deposit Insurance Corporation (“FDIC”), Canadian Deposit Insurance Corporation (“CDIC”) and other foreign insurance limits. Financial instruments that potentially subject the Company to concentrations of credit risk consist principally of cash deposits. The amounts in excess of FDIC, CDIC and other foreign insurance limits were approximately $40,691$34,439 and $39,306$43,200 at December 31, 20152016 and September 30, 2016,2017, respectively.
Note 4—5—Restricted Cash

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. Short-term restricted cash at December 31, 20152016 and September 30, 20162017 consisted of the following:
December 31,
2015
 September 30,
2016
December 31,
2016
 September 30,
2017
Short-term restricted cash: 
  
 
  
Standby letters of credit$1,631
 $1,753
$1,753
 $1,463
Canton Bonds (see Note 10)2,609
 2,876
Canton Bonds (see Note 13)3,665
 
Held in escrow1,578
 
Total short-term restricted cash$4,240
 $4,629
$6,996
 $1,463



Note 5—6—Investments
Available-for-sale securities are carried at fair value, inclusive of unrealized gains and losses. Unrealized gains and losses are included in other comprehensive income (loss), net of applicable income taxes. Gains or losses on sales of available-for-sale securities are recognized on the specific identification basis. All of the Company’sCompany's short-term investments are classified as available-for-sale securities.
The Company reviews available-for-sale securities for other-than-temporary 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. This evaluation is based on a number of factors, including the length of time and the extent to which the fair value has been below its cost basis and adverse conditions related specifically to the security, including any changes to the credit rating of the security. As of September 30, 2016,2017, the Company believes its carrying values for its available-for-sale securities are properly recorded.
Short-term investments atas of December 31, 2015 consisted of the following:
 Amortized Cost 
Gross Unrealized
Losses
 
Estimated Fair
Value
Municipal bonds and notes$16,797
 $(7) $16,790
Zero coupon bonds500
 (1) 499
Corporate bonds37,181
 (77) 37,104
Certificate of deposits48,551
 
 48,551
Total short-term investments$103,029
 $(85) $102,944







Short-term investments at September 30, 2016 consisted of the following:
Amortized Cost 
Gross Unrealized
Gains (Losses)
 
Estimated Fair
Value
Amortized Cost 
Gross Unrealized
Losses
 
Estimated Fair
Value
Municipal bonds and notes$14,466
 $(4) $14,462
$8,791
 $(4) $8,787
Zero coupon bonds429
 
 429
Corporate bonds15,736
 (14) 15,722
21,517
 (7) 21,510
Certificate of deposits46,700
 
 46,700
43,421
 
 43,421
Total short-term investments$77,331
 $(18) $77,313
$73,729
 $(11) $73,718
Note 6—Other Receivables
Other receivables at December 31, 2015 andShort-term investments as of September 30, 20162017 consisted of the following:
 December 31,
2015
 September 30,
2016
Loans to customers to finance vehicle purchases$10,531
 $9,070
Accrued customer billings7,106
 9,985
Fuel tax credits40,730
 6,275
Other2,300
 3,234
Total other receivables$60,667
 $28,564
 Amortized Cost 
Gross Unrealized
Losses
 
Estimated Fair
Value
Municipal bonds and notes$21,470
 $(73) $21,397
Zero coupon bonds69,192
 (59) 69,133
Corporate bonds39,596
 (13) 39,583
Certificate of deposits21,408
 
 21,408
Total short-term investments$151,666
 $(145) $151,521
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; 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.
As of September 30, 2017, the Company's financial instruments consisted of available-for-sale securities, liability-classified warrants, and debt instruments. The Company’s available-for-sale securities 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 liability-classified warrants are classified within Level 3 because the Company uses the Black-Scholes option pricing model to estimate the fair value based on inputs that are not observable in any market. The fair values of the Company's debt instruments approximated their carrying values as of December 31, 2016 and September 30, 2017. See Note 13 for more information about the Company's debt instruments. There were no transfers of assets between Level 1, Level 2, or Level 3 of the fair value hierarchy as of December 31, 2016 and September 30, 2017, respectively.

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, 2016 and September 30, 2017, respectively:
Description Balance at
December 31, 2016
 Level 1 Level 2 Level 3
Assets:        
Available-for-sale securities(1):        
Municipal bonds and notes $8,787
 $
 $8,787
 $
Corporate bonds 21,510
 
 21,510
 
Certificate of deposits 43,421
 
 43,421
 
Liabilities:        
Warrants(2) 581
 
 
 581
Description Balance at
September 30, 2017
 Level 1 Level 2 Level 3
Assets:        
Available-for-sale securities(1):        
Municipal bonds and notes $21,397
 $
 $21,397
 $
   Zero coupon bonds 69,133
 
 69,133
 
Corporate bonds 39,583
 
 39,583
 
Certificate of deposits 21,408
 
 21,408
 
Liabilities:        
Warrants(2) 543
 
 
 543
(1) Included in short-term investments in the condensed consolidated balance sheets. See Note 6 for more information.
(2) Included in accrued liabilities and other long-term liabilities in the condensed consolidated balance sheets.

Non-Financial Assets
During the three and nine months ended September 30, 2017, long-lived assets held and used with a carrying value of $59,367 were written down to their fair value of $6,709, resulting in charges of $52,658. The fair value of these assets was determined using Level 3 inputs. See Note 2 for more information.
No impairments were incurred during 2016.
Note 8—Other Receivables
Other receivables as of December 31, 2016 and September 30, 2017 consisted of the following:
 December 31,
2016
 September 30,
2017
Loans to customers to finance vehicle purchases$7,416
 $6,896
Accrued customer billings4,308
 6,328
Fuel tax credits6,358
 
Other3,852
 3,029
Total other receivables$21,934
 $16,253
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 market. The Company writes down the carrying value of its inventory to net realizable value for estimated obsolescence or unmarketable inventory in an amount equal to the difference between the cost of inventory and its estimated realizable value based upon assumptions about future demand and market conditions, among other factors.
Inventories atas of December 31, 20152016 and September 30, 20162017 consisted of the following:

December 31,
2015
 September 30,
2016
December 31,
2016
 September 30,
2017
Raw materials and spare parts(1)$25,113
 $23,941
$24,843
 $42,487
Work in process973
 2,195
845
 806
Finished goods3,203
 3,319
3,856
 1,331
Total inventories$29,289
 $29,455
$29,544
 $44,624
(1)As of September 30, 2017, this amount also includes $19,394 for certain station parts which historically were classified as construction in progress within Land, property, and equipment, net, that are now reported in Inventory in the condensed consolidated balance sheets because they will primarily be used for stations to be sold. See Note 2 for more information.
Note 8—10—Land, Property and Equipment
Land, property and equipment atas of December 31, 20152016 and September 30, 20162017 consisted of the following:
December 31,
2015
 September 30,
2016
December 31,
2016
 September 30,
2017
Land$2,858
 $2,858
$2,858
 $2,858
LNG liquefaction plants94,634
 94,634
94,634
 94,633
RNG plants(1)46,397
 47,154
47,545
 
Station equipment(2)316,258
 333,440
341,605
 298,681
Trailers50,414
 51,730
54,985
 59,312
Other equipment(2)83,687
 90,762
93,118
 94,389
Construction in progress139,586
 124,199
Construction in progress (2) (3)117,662
 79,366
733,834
 744,777
752,407
 629,239
Less: accumulated depreciation(217,510) (256,855)(268,484) (265,466)
Total land, property and equipment$516,324
 $487,922
Total land, property and equipment, net$483,923
 $363,773

(1) The RNG plants were sold in the Asset Sale (see Note 3 for more information).
(2)Certain of these assets were written down during the three months ended September 30, 2017 (see Note 2 for more information).
(3)As of September 30, 2017, $19,394 of certain station parts which historically were classified as construction in progress within Land, property, and equipment, net, that are now reported in Inventory in the condensed consolidated balance sheets because they will primarily be used for stations to be sold.
Included in land, property and equipment are capitalized software costs of $22,886$25,728 and $24,872 at$27,056 as of December 31, 20152016 and September 30, 2016,2017, respectively. The accumulated amortization onof the capitalized software costs is $13,793$17,237 and $16,402 at$20,371 as of December 31, 20152016 and September 30, 2016,2017, respectively.
The Company recorded amortization expense related to the capitalized software costs of $692$824 and $824$1,140 during the three months ended September 30, 20152016 and 2016,2017, respectively, and $2,239$2,609 and $2,609$3,134 during the nine months ended September 30, 20152016 and 2016,2017, respectively.
AtAs of September 30, 20152016 and 2016, $6,2492017, $4,139 and $4,139,$2,007, respectively, are included in accounts payable and accrued liabilities balances, which amounts are related to purchases of property and equipment. These amounts are excluded from the condensed consolidated statements of cash flows as they are non-cash investing activities.
Note 9—11— Investments in Other Entities and Noncontrolling Interest in a Subsidiary
RNG Ventures
In November 2016, Renewables entered into agreements to form joint ventures with Aria Energy Operating LLC ("Aria"), a developer of RNG production facilities, to develop RNG production facilities at a Republic Services landfill in Oklahoma City, Oklahoma and an Advanced Disposal landfill near Atlanta, Georgia. These joint ventures are referred to as the "RNG Ventures." Renewables' interest in the RNG Ventures was transferred to BP upon completion of the Asset Sale (see Note 3 for more information); however, Renewables retained the right to purchase 100% of the RNG that will be produced by the production facilities to be developed by the RNG Ventures for the vehicle fuels market. The Company accounted for its interest in the RNG Ventures using the equity method of accounting as the Company had the ability to exercise significant influence over these

operations. The Company had an investment balance of $833 and $0 in the RNG Ventures as of December 31, 2016 and September 30, 2017, respectively.

MCEP
On September 16, 2014, the Company formed a joint venture with Mansfield Ventures LLC (“Mansfield”) called Mansfield Clean Energy Partners LLC (“MCEP”), which is designed to provide natural gas fueling solutions to bulk fuel haulers in the United States. The Company and Mansfield each have a 50% ownership interest in MCEP. The Company accounts for its interest in MCEP using the equity method of accounting, as the Company has the ability to exercise significant influence over MCEP’s operations. The Company recorded loss from this investment of $13 and $30 for the three months ended September 30, 2016 and 2017, respectively, and $20 and $100 for the nine months ended September 30, 2016 and 2017, respectively. Additionally, on June 28, 2016, the Company received a return of capital of $3,031 with no change in ownership interest. The Company has an investment balance of $1,642 and $1,542 at December 31, 2016 and September 30, 2017, respectively.
NG Advantage
On October 14, 2014, the Company entered into a Common Unit Purchase Agreement (“UPA”) with NG Advantage, LLC (“NG Advantage”) for a 53.3% controlling interest in NG Advantage. 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 viewed the acquisition as a strategic investment in the expansion of the Company’s initiative to deliver natural gas to industrial and institutional energy users. The results of NG Advantage’s operations have been included in the Company’s consolidated financial statements since October 14, 2014.
On July 14, 2017, the Company contributed to NG Advantage all of its right, title and interest in and to a CNG station located in Milton, Vermont. The Company had purchased this CNG station from NG Advantage in October 2014 in connection with the UPA, and at that time, the Company entered into a lease agreement with NG Advantage to lease the station back to NG Advantage. This lease agreement was terminated contemporaneously with the contribution of the station to NG Advantage in July 2017. As consideration for the contribution, NG Advantage issued to the Company Series A Preferred Units with an aggregate value of $7,500. The Series A Preferred Units provide for an accrued return in the event of a liquidation event with respect to NG Advantage and will convert into common units of NG Advantage if and when it completes a future equity financing that satisfies certain specified conditions, but the Series A Preferred Units do not, in themselves, increase the Company's controlling interest in NG Advantage. As a result, following the contribution, the Company's controlling interest in NG Advantage remains at 53.3%.

The Company recorded a loss from the noncontrolling interest in NG Advantage of $391 and $747 for the three months ended September 30, 2016 and 2017, respectively, and $1,317 and $1,813 for the nine months ended September 30, 2016 and 2017, respectively. The noncontrolling interest was $24,822 and $23,009 as of December 31, 2016 and September 30, 2017, respectively.
Note 12—Accrued Liabilities
Accrued liabilities atas of December 31, 20152016 and September 30, 20162017 consisted of the following:
December 31,
2015
 September 30,
2016
December 31,
2016
 September 30,
2017
Accrued alternative fuel incentives (1)$15,651
 $12,653
Accrued alternative fuels incentives (1)$9,840
 $2,270
Accrued employee benefits3,042
 3,534
4,317
 3,999
Accrued interest3,718
 4,952
1,849
 39
Accrued gas and equipment purchases14,133
 12,126
11,657
 10,220
Accrued property and other taxes5,344
 3,850
4,572
 4,164
Salaries and wages(2)9,537
 9,478
12,293
 8,636
Other(3)7,657
 7,674
8,073
 12,662
Total accrued liabilities$59,082
 $54,267
$52,601
 $41,990
(1)Includes the amount of RINs and LCFS Credits and, as of December 31, 2016, the amount of a federal alternative fuels tax credit ("VETC") payable to third parties. VETC expired as of December 31, 2016, and as a result, no VETC amounts were accrued as of September 30, 2017 (see Note 18 for more information about VETC).
(2)The amount as of September 30, 2017 includes severance accruals related to a workforce reduction during the three months ended September 30, 2017 (see Note 2 for more information).
(1) Included in these balances are federal alternative fuels tax credit ("VETC") (discussed in Note 17 below) and tradable credits related to renewable identification numbers ("RIN Credits") and low carbon fuel standards ("LCFS Credits") payable to third parties.
(3)The amount as of September 30, 2017 also includes lease termination fees and AROs related to closure of certain fueling stations (see Note 2 for more information).
Note 10—13—Debt
Debt and capital lease obligations atas of December 31, 20152016 and September 30, 20162017 consisted of the following and are further discussed below:
December 31, 2015December 31, 2016
Principal Balances Unamortized Debt Financing Costs Balance, Net of Financing CostsPrincipal Balances Unamortized Debt Financing Costs Balance, Net of Financing Costs
7.5% Notes(1)$150,000
 $399
 $149,601
SLG Notes145,000
 38
 144,962
7.5% Notes (1)$150,000
 $274
 $149,726
5.25% Notes250,000
 3,985
 246,015
110,450
 1,088
 109,362
Plains Credit Facility23,500
 
 23,500
Canton Bonds10,910
 514
 10,396
9,520
 373
 9,147
Capital lease obligations6,448
 
 6,448
6,028
 
 6,028
NG Advantage debt13,068
 237
 12,831
Other debt10,056
 328
 9,728
1,782
 
 1,782
Total debt and capital lease obligations572,414
 5,264
 567,150
314,348
 1,972
 312,376
Less amounts due within one year(150,129) (273) (149,856)(6,126) (183) (5,943)
Total long-term debt and capital lease obligations$422,285
 $4,991
 $417,294
$308,222
 $1,789
 $306,433
September 30, 2016September 30, 2017
Principal Balances Unamortized Debt Financing Costs Balance Net of Financing CostsPrincipal Balances Unamortized Debt Financing Costs Balance Net of Financing Costs
7.5% Notes(1)$150,000
 $304
 $149,696
7.5% Notes (1)$125,000
 $155
 $124,845
5.25% Notes179,600
 2,037
 177,563
110,450
 609
 109,841
Canton Bonds9,520
 409
 9,111
Capital lease obligations5,886
 
 5,886
868
 
 868
NG Advantage debt18,070
 236
 17,834
Other debt10,535
 171
 10,364
1,456
 
 1,456
Total debt and capital lease obligations355,541
 2,921
 352,620
255,844
 1,000
 254,844
Less amounts due within one year(5,028) (177) (4,851)(29,305) (58) (29,247)
Total long-term debt and capital lease obligations$350,513

$2,744
 $347,769
$226,539

$942
 $225,597

(1) Included in the 7.5% Notes isIncludes $65,000 and $40,000 in principal amount held by T. Boone Pickens ("Mr. Pickens"), as of December 31, 2016 and September 30, 2017, respectively, which is classified as “Long-term debt, related party” on the condensed consolidated balance sheet. See the description below for additionalmore information.

7.5% Notes
On July 11, 2011, the Company entered into a loan agreement (the “CHK Agreement”) with Chesapeake NG Ventures Corporation (“Chesapeake”), an indirect wholly owned subsidiary of Chesapeake Energy Corporation, whereby Chesapeake agreed to purchase from the Company up to $150,000 of debt securities pursuant to the issuance of three convertible promissory notes over a three-year period, each having a principal amount of $50,000 (each a “CHK Note” and collectively the “CHK Notes” and, together with the CHK Agreement and other transaction documents, the “CHK Loan Documents”). The first CHK Note was issued on July 11, 2011 and the second CHK Note was issued on July 10, 2012.
On June 14, 2013 (the “Transfer Date”), T. BooneMr. Pickens and Green Energy Investment Holdings, LLC ("GEIH"), an affiliate of Leonard Green & Partners, L.P. (collectively, the “Buyers”), and Chesapeake entered into a note purchase agreement (“Note Purchase Agreement”) pursuant to which Chesapeake sold the outstanding CHK Notes (the “Sale”) to the Buyers. Chesapeake assigned to the Buyers all of its right, title and interest under the CHK Loan Documents (the “Assignment”), and each Buyer severally assumed all of the obligations of Chesapeake under the CHK Loan Documents arising after the Sale and the Assignment including, without limitation, the obligation to advance an additional $50,000 to the Company in June 2013 (the “Assumption”). The Company also entered into the Note Purchase Agreement for the purpose of consenting to the Sale, the Assignment and the Assumption.

Contemporaneously with the execution of the Note Purchase Agreement, the Company entered into a loan agreement with each Buyer (collectively, the “Amended Agreements”). The Amended Agreements have the same terms as the CHK Agreement, other than changes to reflect the new holders of the CHK Notes. Immediately following execution of the Amended Agreements, the Buyers delivered $50,000 to the Company in satisfaction of the funding requirement they had assumed from Chesapeake (the “2013 Advance”). In addition, the Company canceled the existing CHK Notes and issued replacement notes, and the Company also issued notes to the Buyers in exchange for the 2013 Advance (the replacement notes and the notes issued in exchange for the 2013 Advance are referred to herein as the “7.5% Notes”).
The 7.5% Notes have the same terms as the original CHK Notes, other than the changes to reflect their different holders. They bear interest at the rate of 7.5% per annum and are convertible at the option of the holder into shares of the Company’s common stock at a conversion price of $15.80 per share (the “7.5% Notes Conversion Price”). Upon written notice to the Company, each holder of a 7.5% Note has the right to exchange all or any portion of the principal and accrued and unpaid interest under its 7.5% Notes for shares of the Company’s common stock at the 7.5% Notes Conversion Price.
Additionally, subject to certain restrictions, the Company can force conversion of each 7.5% Note into shares of its common stock if, following the second anniversary of the issuance date of a 7.5% Note, such shares trade at a 40% premium to the 7.5% Notes Conversion Price for at least 20 trading days in any consecutive 30 trading day period.
The entire principal balance of each 7.5% Note is due and payable seven years following its issuance and the Company may repay each 7.5% Note at maturity in shares of its common stock (with a value determined by the per share volume weighted-average price for the 20 trading days prior to the maturity date) or cash. All of the shares issuable upon conversion of the 7.5% Notes have been registered for resale by their holders pursuant to a registration statement that has been filed with and declared effective by the Securities and Exchange Commission.

The Amended Agreements provide for customary events of default which, if any of them occurs, would permit or require the principal of, and accrued interest on, the 7.5% Notes to become, or to be declared, due and payable. No events of default under the 7.5% Notes had occurred as of September 30, 2016.2017.
On August 27, 2013, Green Energy Investment Holdings, LLCGEIH transferred $5,000 in principal amount of its 7.5% Notes to certain third parties.
On February 9, 2017, the Company purchased from Mr. Pickens, his 7.5% Note due July 2018 having an outstanding principal amount of $25,000 held by Mr. Pickens for a cash purchase price of $21,750. The Company's repurchase of this 7.5% Note resulted in a total gain of $3,191 for the three and nine months ended September 30, 2017.
On February 21, 2017, GEIH transferred an additional $11,800 in principal amount of its 7.5% Notes to a third party.
As a result of the foregoing transactions, as of September 30, 2017, (i) T. BooneMr. Pickens holdsheld 7.5% Notes in the aggregate principal amount of $65,000,$40,000, (ii) Green Energy Investment Holdings, LLC holdsGEIH held 7.5% Notes in the aggregate principal amount of $80,000,$68,200, and (iii) other third parties holdheld 7.5% Notes in the aggregate principal amount of $5,000.
SLG Notes
On August 24, 2011, the Company entered into convertible note purchase agreements (each, an “SLG Agreement” and collectively the “SLG Agreements”) with certain purchasers (each, a “Purchaser” and collectively, the “Purchasers”), pursuant to which the Purchasers agreed to purchase from the Company $150,000 of 7.5% convertible promissory notes due in August 2016 (each a “SLG Note” and collectively the “SLG Notes”). The transaction closed and the SLG Notes were issued on August 30, 2011.
On March 1, 2016, and pursuant to the consent of the holders of the SLG Notes, the Company prepaid in cash an aggregate of $60,000 in principal amount and $1,812 in accrued and unpaid interest owed under the SLG Notes.
On July 14, 2016, the Company entered into separate privately negotiated exchange agreements with each holder of an SLG Note to exchange the outstanding principal amount of each SLG Note, totaling $85,000 for all SLG Notes and all accrued and unpaid interest thereon, totaling $248 for all SLG Notes, for an aggregate of 14,000,000 shares of the Company's common stock and $38,155 in cash. The value of the shares of the Company's common stock issued to the holders of the SLG Notes in the exchange has been excluded from the Company's condensed consolidated statements of cash flows, as it is a non-cash financing activity. The Company recognized a loss of $891 in the three months ended September 30, 2016, related to the settlement of the SLG Notes for the Company's common stock. The repurchased and exchanged SLG Notes have been terminated and canceled in full and the Company has no further obligations under the SLG Notes.$16,800.
5.25% Notes
In September 2013, the Company completed a private offering of $250,000 in principal amount of 5.25% Convertible Senior Notes due 2018 (the “5.25% Notes”) and entered into an indenture governing the 5.25% Notes (the “Indenture”).
The net proceeds from the sale of the 5.25% Notes after the payment of certain debt issuance costs of $7,805 were $242,195. The Company has used the net proceeds from the sale of the 5.25% Notes to fund capital expenditures and for general corporate purposes. The 5.25% Notes bear interest at a rate of 5.25% per annum, payable semi-annually in arrears on October 1 and April 1 of each year, beginning on April 1, 2014. The 5.25% Notes will mature on October 1, 2018, unless purchased, redeemed or converted prior to such date in accordance with their terms and the terms of the Indenture.
Holders may convert their 5.25% Notes, at their option, at any time prior to the close of business on the business day immediately preceding the maturity date of the 5.25% Notes. Upon conversion, the Company will deliver a number of shares of its common stock, per $1 principal amount of 5.25% Notes, equal to the conversion rate then in effect (together with a cash payment in lieu of any fractional shares). The initial conversion rate for the 5.25% Notes is 64.1026 shares of the Company’s common stock per $1 principal amount of 5.25% Notes (which is equivalent to an initial conversion price of approximately $15.60 per share of the Company’s common stock). The conversion rate is subject to adjustment upon the occurrence of certain specified events as described in the Indenture. Upon the occurrence of certain corporate events prior to the maturity date of the 5.25% Notes, the Company will, in certain circumstances, in addition to delivering the number of shares of the Company’s common stock deliverable upon conversion of the 5.25% Notes based on the conversion rate then in effect (together with a cash payment in lieu of any fractional shares), pay holders that convert their 5.25% Notes a cash make-whole payment in an amount as calculateddescribed in accordance with

the Indenture. The Company may, at its option, irrevocably elect to settle its obligation to pay any such make-whole payment in shares of its common stock instead of in cash.
The amount of any make-whole payment, whether it is settled in cash or in shares of the Company’s common stock upon the Company’s election, will be determined based on the date on which the corporate event occurs or becomes effective and the stock price paid (or deemed to be paid) per share of the Company’s common stock in the corporate event, as described in the Indenture.


The Company may not redeem the 5.25% Notes prior to October 5, 2016. On or after October 5, 2016, the Company may, at its option, redeem for cash all or any portion of the 5.25% Notes if the closing sale price of the Company’s common stock for at least 20 trading days (whether or not consecutive) during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which notice of redemption is provided, exceeds 160% of the conversion price on each applicable trading day. In the event of the Company’s redemption of the 5.25% Notes, the redemption price will equal 100% of the principal amount of the 5.25% Notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for in the 5.25% Notes.
If the Company undergoes a fundamental change (as defined in the Indenture) prior to the maturity date of the 5.25% Notes, subject to certain conditions as described in the Indenture, holders may require the Company to purchase, for cash, all or any portion of their 5.25% Notes at a repurchase price equal to 100% of the principal amount of the 5.25% Notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change purchase date.
The Indenture contains customary events of default with customary cure periods, including, without limitation, failure to make required payments or deliveries of shares of the Company’s common stock when due under the Indenture, failure to comply with certain covenants under the Indenture, failure to pay when due or acceleration of certain other indebtedness of the Company or certain of its subsidiaries, and certain events of bankruptcy and insolvency of the Company or certain of its subsidiaries. The occurrence of an event of default under the Indenture will allow either the trustee or the holders of at least 25% in principal amount of the then-outstanding 5.25% Notes to accelerate, or upon an event of default arising from certain events of bankruptcy or insolvency of the Company, will automatically cause the acceleration of, all amounts due under the 5.25% Notes. No events of default under the 5.25% Notes had occurred as of September 30, 2016.2017.
The 5.25% Notes are senior unsecured obligations of the Company and rank senior in right of payment to the Company’s future indebtedness that is expressly subordinated in right of payment to the 5.25% Notes; equal in right of payment to the Company’s unsecured indebtedness that is not so subordinated; effectively junior to any of the Company’s secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness (including trade payables) of the Company’s subsidiaries.
The Company's board of directors has authorized and approvedDuring the use of up to $50,000 to purchase outstanding 5.25% Notes in the open market, in accordance with the terms of the Indenture. Pursuant to this approval, during the three and nine monthsyear ended September 30,December 31, 2016, respectively, the Company paid an aggregate of $1,180 and $24,883, respectively,$84,344 in cash to repurchase and retire $1,400 and $45,400, respectively,$114,550 in aggregate principal amount of the 5.25% Notes, together with $28 and $766, respectively,$1,546 in accrued and unpaid interest thereon. Additionally, pursuant to a privately negotiated exchange agreement with certain holders of the 5.25% Notes, on May 4, 2016, the Company issued 6,265,829 shares of its common stock in exchange for an aggregate principal amount of $25,000 of 5.25% Notes held by such holders together withand accrued and unpaid interest thereon. The value of the shares of the Company's common stock issued to the holders of the 5.25% Notes in the exchange has been excluded from the Company's condensed consolidated statements of cash flows as it is a non-cash financing activity. The Company's repurchase and exchange of 5.25% Notes for the three and nine monthsyear ended September 30,December 31, 2016 resulted in a total gain of $223 and $26,266 for such periods, respectively.$35,239 recorded during the period. All repurchased and exchanged 5.25% Notes have been surrendered to the trustee for such notes and canceled.canceled in full and the Company has no further obligations under such notes.
PlainsCapital BankPlains Credit Facility
On February 29, 2016, the Company entered into a Loan and Security Agreement (“(the “Plains LSA”) with PlainsCapital Bank (“Plains”), pursuant to which Plains agreed to lend the Company up to $50,000 on a revolving basis from time to time for a term of one year (the “Credit Facility”). All amounts advanced under the Credit Facility arewere due and payable on February 28, 2017. Simultaneously, the Company drew down $50,000 under this Credit Facility, which the Company repaid in full on August 31, 2016. On October 31, 2016, the Plains LSA was amended solely to extend the Credit Facility's maturity date from February 28, 2017 to September 30, 2018. On December 22, 2016, the Company drew $23,500 under the Credit Facility, which the Company repaid in full on March 31, 2017. As a result, the Company had no amounts outstanding under the Credit Facility as of September 30, 2017.

The Credit Facility is evidenced by a promissory note the Company issued on February 29, 2016 in favor of Plains (the “Plains Note”). Interest on the Plains Note is payable monthly and accrues at a rate equal to the greater of (i) the then-current LIBOR rate plus 2.30% or (ii) 2.70%. As collateral security for the prompt payment in full when due of the Company's obligations

to Plains under the Plains LSA and the Plains Note, the Company pledged to and granted Plains a security interest in all of its right, title and interest in the cash and corporate and municipal bonds rated AAA, AA or A by Standard & Poor’s Rating Services that the Company holds in an account at Plains. In connection with such pledge and security interest granted under the Credit Facility, on February 29, 2016, the Company entered into a Pledged Account Agreement with Plains and PlainsCapital Bank - Wealth Management and Trust (the “Pledge Agreement” and collectively with the Plains LSA and the Plains Note, the “Plains Loan Documents”).The Plains Loan Documents include certain covenants of the Company and also provide for customary events of default, which, if any of them occurs, would permit or require, among other things, the principal of, and accrued interest on, the Credit Facility to become, or to be declared, due and payable. Events of default under the Plains Loan Documents include, among others, the occurrence of certain bankruptcy events, the failure to make payments when due under the Plains Note and the transfer

or disposal of the collateral under the Plains LSA. No amounts were outstanding under the Credit Facility as of September 30, 2016 and no events of default under the Plains Loan Documents had occurred as of September 30, 2016.

On October 31, 2016 the LSA was amended solely to extend the Credit Facility's maturity date from February 28, 2017 to September 30, 2018.2017.

Canton Bonds
On March 19, 2014, Canton Renewables, LLC (“Canton”), a wholly ownedformer subsidiary of the Company, completed the issuance of Solid Waste Facility Limited Obligation Revenue Bonds (Canton Renewables, LLC — Sauk Trail Hills Project) Series 2014 in the aggregate principal amount of $12,400 (the “Canton Bonds”).
The Canton Bonds were issued by the Michigan Strategic Fund (the “Issuer”) and the proceeds of such issuance were loaned by the Issuer to Canton pursuant to a loan agreement that became effective on March 19, 2014 (the “Loan Agreement”)2014.
On March 31, 2017, Canton was sold to BP in the Asset Sale (see Note 3). The Canton Bonds are expected to be repaid from revenue generated by Canton from the sale of RNG and are secured by the revenue and assets of Canton. The Canton Bond repayments will be amortized through July 1, 2022, the average coupon interest rate onAs a result, the Canton Bonds became the obligation of BP as of such date.
NG Advantage Debt
On May 12, 2016 and January 24, 2017, respectively, NG Advantage entered into a Loan and Security Agreement (the “Commerce LSA”) with Commerce Bank & Trust Company (“Commerce”), pursuant to which Commerce agreed to lend NG Advantage $6,300 and $6,150, respectively. The proceeds were primarily used to fund the purchases of CNG trailers and equipment. Interest and principal for both loans are payable monthly in 84 equal monthly installments at an annual rate of 4.41% and 5.0%, respectively. As collateral security for the prompt payment in full when due of NG Advantage's obligations to Commerce under the Commerce LSA, NG Advantage pledged to and granted Commerce a security interest in all of its right, title and interest in the CNG trailers and equipment purchased with the proceeds received under the Commerce LSA.

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 $4,695. The proceeds were primarily used to fund the purchases of CNG trailers and equipment. Interest and principal is 6.6%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.

NG Advantage has other debt for trailers and equipment due at various dates through 2021 bearing interest at rates up to 6.01%, with weighted -average interest rates of 5.51% and 5.56%, and all but $1,000outstanding principal balance of the principal amount of the Canton Bonds is non-recourse to Canton’s parent companies, including the Company.
Canton used the Canton Bond proceeds primarily to (i) refinance the cost of constructing$2,598 and equipping its RNG extraction and production project in Canton, Michigan and (ii) pay a portion of the costs associated with the issuance of the Canton Bonds. The refinancing described in the prior sentence was accomplished through distributions to Canton's direct and indirect parent companies who provided the financing for the RNG production facility, and such companies have used such distributions to finance construction of additional RNG extraction and processing projects and for working capital purposes.    
The Loan Agreement contains customary events of default, with customary cure periods, including, without limitation, failure to make required payments when due under the Loan Agreement, failure to comply with certain covenants under the Loan Agreement, certain events of bankruptcy and insolvency of Canton, and the existence of an event of default under the indenture governing the Canton Bonds that was entered into between the Issuer and The Bank of New York Mellon Trust Company, N.A., as trustee.
The occurrence of an event of default under the Loan Agreement will allow the Issuer or the trustee to, among other things, accelerate all amounts due under the Loan Agreement. No events of default under the Loan Agreement had occurred$3,222 as of December 31, 2016 and September 30, 2016.2017, respectively.

Other Debt
The Company has other debt due at various dates through 2023 bearing interest at rates up to 22.34%19.69% with weighted -average interest rates of 5.72% and with a weighted average interest rate of 6.35% and 5.11% as of December 31, 20152016 and September 30, 2016,2017, respectively.
Note 11—14—Net Income (Loss)Loss Per Share
Basic net income (loss)loss per share is computed by dividing the net income (loss)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 eachthe period. Diluted net income (loss)loss per share is computed by dividing the net income (loss)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.
Potentiallyperiod, and therefore reflects the dilution from common shares that may be issued upon exercise or conversion of these potentially dilutive securities, includesuch as stock options, warrants, convertible notes and restricted stock units. The dilutive effect of stock optionsawards 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)loss per share if their effect would be antidilutive.
At-The-Market Offering ProgramOn November 11, 2015, the Company entered into an equity distribution agreement with Citigroup Global Markets Inc. (“Citigroup”), as sales agent and/or principal, pursuant to which the Company may issue and sell, from time to time, through or to Citigroup shares of its common stock having an aggregate offering price of up to $75,000 in an “at-the-market” offering program (the “ATM Program”).

On September 9, 2016, the Company entered into an amended and restated equity distribution agreement with Citigroup, which amends, restates, and replaces the original equity distribution agreement in its entirety, for the primary purpose of increasing from $75,000 to $110,000, the aggregate offering price of shares of common stock available for issuance and sale thereunder in the ATM Program.
The following table summarizes the activity under the ATM Program for the following periods:
 Through December 31, Three Months Ended
September 30,
 Nine Months Ended
September 30,
 
(in 000s, except per-share amounts)2015 2016 2016 
Gross proceeds$6,943
 $16,066
 $69,113
 
Fees and issuance costs$493
 386
 1,728
 
Net proceeds$6,450
 $15,680
 $67,385
 
Shares issued1,561,902
 3,824,144
 21,325,587
 
GE WarrantOn December 31, 2015, the Company terminated its credit agreement (the "Credit Agreement") with General Electric Capital Corporation ("GE") and all related documents, except for a warrant to purchase up to 1,000,000 shares of the Company's common stock (the "GE Warrant"), which remained outstanding as of September 30, 2016. The shares of the Company's common stock subject to the GE Warrant are included in the basic and diluted net income (loss) per share calculations, as they are issuable upon exercise of the GE Warrant.
On October 4, 2016, the holders of the GE Warrant exercised such warrant in full pursuant to the cashless exercise provisions thereof, which resulted in the Company's issuance to such holders of 997,740 shares of common stock.
The information required to compute basic and diluted net income (loss)loss per share is as follows:
 Three Months Ended
September 30,
 Nine Months Ended
September 30,
 
 2015 2016 2015 2016 
Weighted-average common shares outstanding91,561,613
 130,436,038
 91,454,117
 112,819,041
 
 Three Months Ended
September 30,
 Nine Months Ended
September 30,
 
 2016 2017 2016 2017 
Weighted-average common shares outstanding130,436,038
 150,927,825
 112,819,041
 150,128,204
 
The following potentially dilutive securities have been excluded from the diluted net income (loss)loss per share calculations because their effect would have been antidilutive. Although such securities were antidilutive for the respective periods, they could be dilutive in the future.
Nine Months Ended
September 30,
Three Months Ended
September 30,
Nine Months Ended
September 30,
2015 20162016 20172016 2017
Options10,707,060
 11,582,091
Warrants6,130,682
 
Stock Options11,582,091
 9,648,613
11,582,091
 9,648,613
Convertible Notes35,185,979
 21,006,491
21,006,491
 14,991,521
21,006,491
 14,991,521
Restricted Stock Units2,942,126
 2,432,930
2,432,930
 2,403,266
2,432,930
 2,403,266
Total35,021,512
 27,043,400
35,021,512
 27,043,400
At-The-Market Offering Program
On May 31, 2017, the Company terminated its equity distribution agreement (the “Sales Agreement”) with Citigroup Global Markets Inc. (“Citigroup”), as sales agent and/or principal. The Sales Agreement was terminable at will upon written notification by the Company with no penalty. Pursuant to the Sales Agreement, the Company was entitled to issue and sell, from time to time, through or to Citigroup, shares of its common stock having an aggregate offering price of up to $200,000 in an “at-the-market” offering program (the “ATM Program”). The ATM Program commenced on November 11, 2015 when the Company and Citigroup entered into the original equity distribution agreement, which was amended and restated on September 9, 2016 and again on December 21, 2016 prior to its termination.

The following table summarizes the activity under the ATM Program for the periods presented:
 Three Months Ended September 30, Three Months Ended September 30, Nine Months Ended
September 30,
 Nine Months Ended
September 30,
(in 000s, except per-share amounts)2016 2017 2016 2017
Gross proceeds$16,066
 $
 $69,113
 $10,767
Fees and issuance costs386
 
 1,728
 311
Net proceeds$15,680
 $
 $67,385
 $10,456
Shares issued3,824,144
 
 21,325,587
 3,802,500
Note 12—15—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 condensed consolidated statements of operations during the periods:
 Three Months Ended
September 30,
 Nine Months Ended
September 30,
 
 2015 2016 2015 2016 
Stock-based compensation expense, net of $0 tax in 2015 and 2016$2,656
 $2,077
 $8,009
 $6,533
 
 Three Months Ended
September 30,
 Nine Months Ended
September 30,
 
 2016 2017 2016 2017 
Stock-based compensation expense, net of $0 tax in 2016 and 2017 (1)$2,077
 $2,216
 $6,533
 $6,904
 

(1)     $300 of stock-based compensation expense for the three and nine months ended September 30, 2017 is recorded in asset impairments and other charges in the condensed consolidated statements of operations and is reported in non-cash portion of asset impairments and other charges in the condensed consolidated statements of cash flows. See Note 2 for more information.
At September 30, 2016,2017, there was $9,487$7,194 of total unrecognized compensation costs related to non-vested shares subject to outstanding stock options and restricted stock units, which is expected to be expensed over a weighted-average period of approximately 1.801.60 years.

Note 16—Income Taxes
The Company’s income tax benefit (expense) was $(416) and $44 for the three months ended September 30, 2016 and 2017, respectively, and $(1,229) and $2,183 for the nine months ended September 30, 2016 and 2017, respectively. Tax benefit (expense) for all periods was comprised of taxes due on the Company’s U.S. and foreign operations. The increase in the Company’s income tax benefit for the three months ended September 30, 2017 as compared to the three months ended September 30, 2016 was primarily due to a decrease in the deferred tax expense attributed to the reduction of goodwill amortization following the Asset Sale (see Note 3). The increase in the Company's income tax benefit for the nine months ended September 30, 2017 as compared to the nine months ended September 30, 2016 was primarily due to a deferred tax benefit from the Asset Sale. The effective tax rates for the three and nine months ended September 30, 2016 and 2017 are different from the federal statutory tax rate primarily as a result of losses for which no tax benefit has been recognized.
Following the Asset Sale, the Company also benefited from the utilization of federal and state net operating loss ("NOL") carryovers that offset all of the Company's federal and the majority of its state taxes. In addition to the decrease in its deferred tax liability of $2,493 attributed to the reduction in goodwill following the Asset Sale, the utilization of NOLs also resulted in a decrease of $29,768 in the Company's deferred tax assets attributed to NOLs and a corresponding decrease in the Company's deferred tax asset valuation allowance.
The Company did not record a change in its liability for unrecognized tax benefits or penalties in the three and nine months ended September 30, 2016 or 2017. The net interest incurred was immaterial for both the three and nine months ended September 30, 2016 and 2017, respectively.
Note 13—Environmental Matters, Litigation, Claims, 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 making any expenditures to comply with such laws and regulations that would have a material impact on the Company’sCompany'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. During the course of its operations, theThe Company is also subject to audit by tax and other authorities for varying periods in various federal, state, local and foreign tax jurisdictions. Disputesjurisdictions, and disputes may arise during the course of such audits as to facts and matters of law.these audits. It is impossible to determine the ultimate liabilities that the Company may incur resulting from any suchof these lawsuits, claims, and proceedings, audits, commitments, contingencies and related matters or the timing of these liabilities, if any. If these matters were to ultimately be resolved unfavorably, an outcome not currently anticipated, 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. However, theThe Company, does not, however, anticipate such an outcome and it believes that the ultimate resolution of suchthese matters will not have a material adverse effect on the Company’s consolidated financial position, results of operations, or liquidity.
Note 14—Income Taxes18—Alternative Fuels Excise Tax Credit
In December 2015, the U.S. Congress passed the Consolidated Appropriations Act, which included an alternative fuels tax credit referred to in these condensed consolidated financial statements as "VETC." The Company’scredit was made retroactive to January 1, 2015 and extended through December 31, 2016, except that the alternative fuels tax credit for LNG sold as a vehicle fuel in 2016 was based on the diesel gallon equivalent of LNG sold, rather than the liquid gallon of LNG sold as it was in 2015. As a result, the Company was eligible to receive a credit of $0.50 per gasoline gallon equivalent of CNG sold as a vehicle fuel in 2016 and $0.50 per diesel gallon equivalent of LNG sold as a vehicle fuel in 2016.

Based on the service relationship with its customers, either the Company or its customers claimed the credit. The Company records its VETC credits, if any, as revenue in its condensed consolidated statements of operations because the credits are fully payable and do not need to offset income tax benefit (expense) forliabilities to be received. As such, the three months ended September 30, 2015 and 2016 was $241 and $(416), respectively. The Company'scredits are not deemed income tax (expense) forcredits under the nine months ended September 30, 2015 and 2016 was $(1,353) and $(1,229), respectively. Tax benefit (expense) for all periods was comprised of taxes due on the Company’s U.S. and foreign operations. The increase in the Company’saccounting guidance applicable to income tax provision for the three months ended September 30, 2016 as compared to the income tax provision for the three months ended September 30, 2015 was primarily attributable to an increase in the earnings of foreign subsidiaries. The decrease in the Company’s income tax provision for the nine months ended September 30, 2016 as compared to the income tax provision for the nine months ended September 30, 2015 was primarily attributable to a decrease in the earnings of foreign subsidiaries. The effective tax ratestaxes.
VETC revenue for the three and nine months ended September 30, 20152016 was $6,693 and 2016 are different from the federal statutory tax rate primarily as a result of losses for which no tax benefit has been recognized.
The Company did not record a change in its liability for unrecognized tax benefits or penalties in the three and nine months ended September 30, 2015. The net interest incurred was immaterial for both the three and nine months ended September 30, 2015 and 2016,$19,609, respectively.
The Company increased its reserve for unrecognized tax positions by $17.6 million during the three months ended September 30, 2016. As unrecognized tax positions are not recognized for financial reporting purposes, this position does not have an impact on the balance sheet, statement of operations or statement of cash flows. If this position were VETC ceased to be sustained, then there would be an increase in the Company's deferred tax assets attributed to its federal and state net operating loss carryforwards, as well as an increase to the amount of the Company's deferred tax asset valuation allowance. The increase was attributable to the write-off of unamortized debt issuance costs resulting from the Company's termination of its Credit Agreement with GEavailable after it expired on December 15, 2015. Although the ultimate outcome of this tax position is uncertain, the Company believes that this non-cash charge can31, 2016 and may not be deducted in determining its U.S. taxable incomeavailable for 2015.    
any subsequent period.

Note 15—Fair Value Measurements19—Recently Issued and Adopted Accounting Standards
The Company followsIn May 2017, the authoritative guidanceFASB issued Accounting Standards Update (“ASU”) 2017-09, Compensation - Stock Compensation (Topic 718): Scope Modification Accounting. This ASU allows entities to make certain changes to awards without accounting for fair value measurements with respect to assets and liabilities that are measured at fair value on a recurring basis and non-recurring basis. Underthem as modifications. It does not change the standard, fair value is defined as the exit price, or the amount that would be received to sellaccounting for modifications. Specifically, 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 consistsentity will not apply modification accounting if all of the following three levels: Level 1 inputs are quoted prices (unadjusted) in active markets for identical assetsthe same immediately before and after the change: (1) the award's fair value (or calculated value 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 thatintrinsic value if those measurement methods are not active,used), (2) the award's vesting conditions, and inputs (other than quoted prices) that are observable for(3) the assetaward's classification as an equity or liability either directly or indirectly; Level 3 inputs are unobservable inputs for

the asset or liability. Categorization within the valuation hierarchyinstrument. The new standard is based upon the lowest level of input that is significant to the fair value measurement.
At September 30, 2016, the Company’s financial instruments consisted of available-for-sale securities, liability-classified warrants, and debt instruments. The Company’s available-for-sale securities 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 liability-classified warrants are classified within Level 3 because the Company uses the Black-Scholes option pricing model to estimate the fair value based on inputs that are not observable in any market. The fair value of the Company's debt instruments approximated their carrying values at December 31, 2015 and September 30, 2016. See Note 10 for further information about the Company's debt instruments.
The following tables provide information by level for assets and liabilities that are measured at fair value on a recurring basis at December 31, 2015 and September 30, 2016, respectively:
Description Balance at
December 31, 2015
 Level 1 Level 2 Level 3
Assets:        
Available-for-sale securities(1):        
Certificate of deposits $48,551
 $
 $48,551
 $
Municipal bonds and notes 16,790
 
 16,790
 
Zero coupon bonds 499
 
 499
 
Corporate bonds 37,104
 
 37,104
 
Liabilities:        
Warrants(2) 632
 
 
 632
Description Balance at
September 30, 2016
 Level 1 Level 2 Level 3
Assets:        
Available-for-sale securities(1):        
Certificate of deposits $46,700
 $
 $46,700
 $
Municipal bonds and notes 14,462
 
 14,462
 
   Zero coupon bonds 429
 
 429
 
Corporate bonds 15,722
 
 15,722
 
Liabilities:        
Warrants(2) 579
 
 
 579
(1) Included in short-term investments in the condensed consolidated balance sheets. See Note 5 for further information.
(2) Included in accrued liabilities and other long-term liabilities in the condensed consolidated balance sheets.

Non-Financial Assets
No impairments of long-lived assets measured at fair value on a non-recurring basis have been incurred during the nine months ended September 30, 2015 and 2016. The Company’s use of these non-financial assets does not differ from their highest and best use as determined from the perspective of a market participant.
Note 16—Recently Issued Accounting Standards
The Financial Accounting Standards Board ("FASB") has issued three amendments to the new revenue standard, ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606), as follows:

    In May 2016, the FASB issued ASU No. 2016-12, Revenue from Contracts with Customers: Narrow-Scope Improvements and Practical Expedients. This update clarifies the objectives of collectability, sales and other taxes, non-cash consideration, contract modifications at transition, completed contracts at transition and technical correction.


    In April 2016, the FASB issued ASU No. 2016-10, Revenue from Contracts with Customers: Identifying Performance Obligations and Licensing. This update clarifies how an entity identifies performance obligations related to customer contracts and helps to improve the operability and understanding of the licensing implementation guidance.

    In August 2015, the FASB issued ASU No. 2015-14, Revenue from Contracts with Customers, Deferral of the Effective Date, which defers the new revenue guidance to be effective for annual reporting periodsfiscal years beginning after December 15, 2017, including interim reporting periods within that reporting period, which for the Company is the first quarter of 2018, using one of two prescribed retrospective methods.2018. The Company is evaluatingdoes not expect the adoption of the guidance to have a material impact on its consolidated financial statements.

In January 2017, the FASB issued ASU 2017-03, Accounting Changes and Error Corrections (Topic 250) and Investments - Equity Method and Joint Ventures (Topic 323): Amendments to SEC Paragraphs Pursuant to Staff Announcements at the September 22, 2016 and November 17, 2016 EITF Meetings. This ASU requires registrants to disclose the effect that ASU 2014-09 (Revenue from Contracts with Customers (Topic 606), ASU 2016-02 (Leases (Topic 842), and ASU 2016-13 (Financial Instruments--Credit Losses (Topic 326) will have on their financial statements when adopted in a future period. In cases where a registrant cannot reasonably estimate the impact of the adoption, additional qualitative disclosures should be considered to assist the reader in assessing the significance of the standard’s impact on its financial statements. This guidance was effective upon issuance and other than enhancements to the qualitative disclosures regarding the future adoption of the referenced ASUs above, adoption of this ASU willis not expected to have any impact on itsthe Company’s consolidated financial statements and related disclosures as well as which transition method it will adopt.disclosures.

In October 2016, the FASB issued ASU No. 2016-16, Income Taxes (Topic 740): Intra-Entity Transfers of Assets Other Than Inventory. Under the new pronouncement,standard, the selling (transferring) entity is required to recognize a current tax expense or benefit upon transfer of the asset. Similarly, the purchasing (receiving) entity is required to recognize a deferred tax asset or liability, as well as the related deferred tax benefit or expense, upon purchase or receipt of the asset. This pronouncement is effective for reporting periods beginning after December 15, 2017, with early adoption permitted. The Company is evaluatingearly adopted the impact this ASU will have on its consolidated financial statements and related disclosures.

In September 2016,standard as of January 1, 2017. This election was implemented under the FASB issued ASU No. 2016-15, Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Payments. The ASU provides clarification as tomodified retrospective approach, resulting in a $302 increase in accumulated deficit representing the classification of certain transactions as operating, investing or financing activities. This pronouncement is effective for reporting periods beginning after December 15, 2017, which for the Company is the first quarter of 2018. The Company is evaluating the impact this ASU will have on its consolidated financial statements and related disclosures.

In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments - Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments. The ASU amends the impairment model to utilize an expected loss methodology in placecumulative recognition of the currently used incurred loss methodology, which will result inincome tax consequences of intra-entity transfers of assets other than inventory that occurred before the more timely recognition of losses. This pronouncement is effective for reporting periods beginning after December 15, 2019, which for the Company is the first quarter of 2020. The Company is evaluating the impact this ASU will have on its consolidated financial statements and related disclosures.adoption date.

In March 2016, the FASB issued ASU No. 2016-09, Compensation – Stock Compensation (Topic 718): Improvements to Employee Share-Based Payments Accounting. The pronouncementnew standard was issued to simplify the accounting for share-based payment transactions, including income tax consequences, the classification of awards as either equity or liabilities, and the classification on the statement of cash flows. This pronouncement is effective for reporting periods beginning after December 15, 2016. Early adoption is allowed in an interim or annual reporting period. The Company adopted the standard as of January 1, 2017 and in connection with the adoption, the Company elected to recognize forfeitures when they occur. Previously, the Company estimated a forfeiture rate in accordance with prior guidance. This election was implemented under the modified retrospective approach with a cumulative effect of an increase in accumulated deficit of $194, net of tax. This adjustment represents the cumulative additional compensation expense that would have been amortized through the date of adoption had this accounting policy election been in place. This ASU also eliminates the requirement to defer recognition of an excess tax benefit until the benefit is evaluatingrealized through a reduction to taxes payable. As a result, the Company’s deferred tax asset relating to its net operating loss carryovers increased by $8,600 with a corresponding increase in the deferred tax asset valuation allowance. The Company also adopted, on a prospective basis, (1) the classification of excess tax benefits as an operating activity in the condensed consolidated statements of cash flows and (2) the exclusion of the amount of excess tax benefits when applying the treasury stock method for the Company’s diluted loss per share calculation. Neither of these adoptions had a material impact this ASU will have on itsthe Company's cash flows or diluted loss per share calculation for the nine months ended September 30, 2017. Additionally, the Company continues to (1) classify cash paid by the Company for directly withholding shares for tax withholding purposes as a financing activity in the condensed consolidated financial statements of cash flows and related disclosures.(2) withhold the statutory minimum taxes for participants in the Company’s stock-based compensation plans.

In February 2016,May 2014, the FASB issued ASU No. 2016-02, Leases.2014-09 related to revenue from contracts with customers, which, along with amendments issued in 2015, 2016, and 2017 will provide a single, comprehensive revenue recognition model for all contracts with customers. The underlying principle is to recognize revenue when promised goods or services are transferred to customers in amounts that reflect the consideration that is expected to be received for those goods or services. The new standard also requires entities to enhance disclosures about the nature, amount, timing and uncertainty of revenue and cash flows arising from contracts with customers. This ASU, as amended, will require most leases to be recognized on the balance sheet which will increase reported assets and liabilities. Lessor accounting remains substantially similar to current guidance. The new standard is effective for annual and interimreporting periods in fiscal years beginning after December 15, 2018, which for the Company is the first quarter of 2019, and mandates a modified retrospective transition method. The Company is evaluating the impact this ASU will have on its consolidated financial statements and related disclosures.

In January 2016, the FASB issued ASU No. 2016-01, Recognition and Measurement of Financial Assets and Financial Liabilities. The new standard requires equity investments to be measured at fair value with changes in fair value recognized in net income, simplifies the impairment assessment of equity investments without readily determinable fair values, eliminates the requirement to disclose the methods and significant assumptions used to estimate fair value, requires use of the exit price notion when measuring fair value, requires separate presentation in certain financial statements, and requires an evaluation of the need for a valuation allowance on a deferred tax asset related to available-for-sale securities. The new standard is effective for fiscal years beginning after December 15, 2017, which for the Company is the first quarter of 2018. The new revenue standard may be applied retrospectively to each prior period presented or retrospectively with the cumulative effect recognized in retained earnings as of the date of adoption ("modified retrospective basis"). The Company expects to adopt this ASU on a modified retrospective basis and is currently evaluating the impact of this ASU will have on its consolidated financial statements and related disclosures. While the Company has not yet identified any material changes in the timing of revenue recognition for our various revenues streams, our evaluation is ongoing and not complete.


Note 20—Subsequent Events
On October 23, 2017, the Company paid $5,486 to settle an obligation to deliver LCFS Credits to a third party. The Company took this action because it did not at that time have access to LCFS Credits it generates due to restrictions imposed on the Company's LCFS Credit account pending completion of an ongoing administrative review by the California Air Resources Board ("CARB"). If CARB's administrative review results in the retirement of any of the Company's LCFS Credits, such that the Company cannot recover any portion of its cash payment through sales of such credits, then the Company may be required to recognize a charge equal to the value of the portion of its cash payment that cannot be recovered.
Note 17—Alternative Fuels Excise Tax Credit
Under separate pieces of U.S. federal appropriations legislation from October 1, 2006 through December 31, 2014, the Company was eligible to receive a federal alternative fuels tax credit (“VETC”) of $0.50 per gasoline gallon equivalent of CNG and $0.50 per liquid gallon of LNG that we sold as vehicle fuel. In December 2015, Congress passed the Consolidated Appropriations Act that included the passage of an alternative fuel tax credit which we continue to refer to as VETC. The credit was made retroactive to January 1, 2015 and extended through December 31, 2016, except that the alternative fuel tax credit for LNG sold as a vehicle fuel in 2016 was changed to be based on the diesel gallon equivalent of LNG sold rather than the liquid gallon of LNG sold.

As a result, the Company was eligible to receive a credit of $0.50 per gasoline gallon equivalent of CNG sold as a vehicle fuel in 2015 and 2016, $0.50 per liquid gallon of LNG sold in 2015 and $0.50 per diesel gallon equivalent of LNG sold in 2016.

Based on the service relationship with its customers, either the Company or its customers claim the credit. The Company records its VETC credits as revenue in its condensed consolidated statements of operations, as the credits are fully payable and do not need to offset income tax liabilities to be received. 
VETC revenues for 2015, totaling $30,986, were all recognized in December 2015. VETC revenues for the three and nine months ended September 30, 2016 were $6,693 and $19,609, respectively.

Item 2.  Management’s Discussion and Analysis of Financial Condition and Results of Operations
The following Management’s Discussion and Analysis of Financial Condition and Results of Operations (the “MD&A”) should be read together with the unaudited condensed consolidated financial statements and the related notes included in this report. For additional context with which to understand our financial condition and results of operations, refer to the MD&A for the fiscal year ended December 31, 20152016 included in our Annual Report on Form 10-K for our fiscal year ended December 31, 2015,2016, which was filed with the Securities and Exchange Commission (“SEC”) on March 3, 2016,7, 2017, as well as the audited consolidated financial statements and notes included therein (collectively, our “2015“2016 Form 10-K”). Unless the context indicates otherwise, all references to “Clean Energy,” the “Company,” “we,” “us,” or “our” in this MD&A and elsewhere in this report refer to Clean Energy Fuels Corp. together with its majority and wholly owned subsidiaries.
Cautionary Statement Regarding Forward Looking Statements
This MD&AManagement’s Discussion and Analysis of Financial Condition and Results of Operations (the “MD&A”) and other sections of this report contain forward-looking statements as defined bywithin the “safe harbor” provisionsmeaning of Section 27A of the Private Securities Litigation Reform Act of 1995.1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements relate to future events or circumstances or our future financial performance and are based upon our current assumptions, expectations and beliefs concerning future developments and their potential effect on our business. In some cases, you can identify theseforward-looking statements by forward-looking words such asthe following words: “if,” “shall,” “may,” “might,” “could,“shall,” “will,” “should,“can,” “could,” “would,” “should,” “expect,” “intend,” “plan,” “goal,” “objective,” “initiative,” “anticipate,” “believe,” “estimate,” “predict,” “project,” “intend,“forecast,“goal,“potential,“objective,“continue,“predict,” “potential” or “continue,”“ongoing” or the negative of these terms or other comparable terminology, although the absence of these words does not mean that a statement is not forward-looking. These forward-lookingWe believe the statements which are based on various assumptions and expectations that we believe are reasonable, may include statementsmake in this MD&A about among other things, our future financial and operating performance, our growth strategies and anticipated trends in our industry and our business. Thesebusiness are forward-looking by their nature. Although the forward-looking statements in this MD&A reflect our good faith judgment, based on currently available information, they are only predictions and involve known and unknown risks, uncertainties and other factors that couldmay cause our or our industry's actual results, levels of activity, performance or achievements to differbe materially different from the historical orany future results, levels of activity, performance or achievements expressed or implied by suchthese forward-looking statements. These factorsFactors that might cause or contribute to such differences include, among others, those discussed under “Risk Factors” in this report and in our 20152016 Form 10-K. WeAs a result of these and other potential risk factors, the forward-looking statements in this MD&A may not prove to be accurate. All forward-looking statements in this MD&A are made only as of the date of this document and, except as required by law, we undertake no dutyobligation to update publicly any of these forward-looking statements after the date we file this reportfor any reason, including to conform such forward-lookingthese statements to actual results or revised expectations, except as otherwise required by law.
In preparing this MD&A, we presume that readers have access to and have read the MD&Achanges in our 2015 10-K pursuant to Instruction 2 to paragraph (b) of Item 303 of Regulation S-K promulgated by the SEC.expectations.

Overview
We are the leading provider of natural gas as an alternative fuel for vehicle fleets in the United States and Canada, based on the number of stations operated and the amount of gasoline gallon equivalents ("GGEs") of renewable natural gas ("RNG"), compressed natural gas ("CNG"), and liquefied natural gas ("LNG") and renewable natural gas ("RNG") delivered. Our principal business is supplying RNG, CNG LNG and RNGLNG (RNG can be delivered in the form of CNG or LNG) for light, medium and heavy-duty vehicles and providing operation and maintenance ("O&M") services for natural gas fuelingvehicle fleet customer stations. As a comprehensive solution provider, we also:also design, build, operate and maintain fueling stations; manufacture, sell and service non-lubricated natural gas fueling compressors and relatedother equipment used in CNG stations and LNG stations; offer assessment, design and modification solutions to provide operators with code-compliant service and maintenance facilities for natural gas vehicle fleets; transport and sell CNG and LNG to industrial and institutional energy users who do not have direct access to natural gas pipelines; processprocure and sell RNG; sell tradable credits we generate by selling natural gas and RNG as a vehicle fuel, including credits under the California and Oregon Low Carbon Fuel Standards (collectively, "LCFS Credits") and Renewable Identification Numbers ("RIN Credits" or "RINs") under the federal Renewable Fuel Standard Phase 2; help our customers acquire and finance natural gas vehicles; and obtain federal, state and local tax credits, grants and incentives.

We serve fleet vehicle operators in a variety of markets, including heavy-duty trucking, airports, refuse, public transit, government fleets, and industrial and institutional energy users. We believe these fleet markets will continue to present a growth

opportunity for natural gas vehicle fuelsfuel for the foreseeable future. As of September 30, 2016,2017, we serve nearly 1,000 fleet customers operating over 44,00046,000 natural gas vehicles, and we currently own, operate or supply overmore than 575 natural gas fueling stations in 42 states in the United States and four provinces in British ColumbiaCanada (although we will close certain underperforming stations) by the end of 2017, as discussed under “Recent Developments” below and Ontario, Canada.Note 2 to the condensed consolidated financial statements included in this report).

Performance Overview



The following performance overview discusses matters on which our management focuses in evaluating our financial condition and operating performance and results.

Sources of Revenue
The following table presentsrepresents our sources of revenue during the periods presented:revenue:
Revenue (in millions) Three Months
Ended
September 30,
2015
 Three Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2015
 Nine Months
Ended
September 30,
2016
 Three Months
Ended
September 30,
2016
 Three Months
Ended
September 30,
2017
 Nine Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2017
Volume Related $67.9
 $71.3
 $195.8
 $210.8
Volume -Related (1) $71.3
 $63.1
 $210.8
 $200.0
Compressor Sales 12.9
 5.3
 41.4
 22.4
 5.3
 5.9
 22.4
 17.6
Station Construction Sales 11.5
 13.7
 27.5
 48.0
 13.7
 12.5
 48.0
 34.1
VETC(2) 
 6.7
 
 19.6
 6.7
 
 19.6
 
Other 
 
 0.3
 
 
 0.3
 
 0.6
Total $92.3
 $97.0
 $265.0
 $300.8
 $97.0
 $81.8
 $300.8
 $252.3
(1)Our volume-related revenue primarily consists of sales of CNG, LNG and RNG fuel, sales of RINs and LCFS Credits and performance of O&M services.
(2)Represents a federal alternative fuels tax credit that we refer to as "VETC," which expired December 31, 2016.

Key Operating Data
In evaluating our operating performance, our management focuses primarily on: (1) the amount of CNG, LNG and RNG gasoline gallon equivalents delivered (which we define as (i) the volume of gasoline gallon equivalents we sell to our customers, plus (ii) the volume of gasoline gallon equivalents dispensed at facilities we do not own but where we provide O&M services on a per-gallon or fixed fee basis, plus (iii) our proportionate share of the gasoline gallon equivalents sold as CNG by our joint venture with Mansfield Ventures, LLC called Mansfield Clean Energy Partners, LLC (“MCEP”), plus (iv) our proportionate share of the gasoline gallon equivalents sold as CNG by our joint venture in Peru (through March 2013 when we sold our interest in the joint venture in Peru), plus (v) our proportionate share (as applicable) of the gasoline gallon equivalents of RNG produced and sold as pipeline quality natural gas by the RNG production facilities we ownowned or operate)operated), (2) our station construction cost of sales, (3) our gross margin (which we define as revenue minus cost of sales), and (3)(4) net income (loss)loss attributable to us. The following tables, which should be read in conjunction with ourthe condensed consolidated financial statements and notes included in this report and ourthe consolidated financial statements and notes included in our 20152016 Form 10-K, presentspresent our key operating data for the years ended December 31, 2013, 2014, 2015, and 20152016 and for the three and nine months ended September 30, 20152016 and 2016:
Gasoline gallon equivalents
delivered (in millions)
 
Year Ended
December 31,
2013
 
Year Ended
December 31,
2014
 
Year Ended
December 31,
2015
 Three Months
Ended
September 30,
2015
 Three Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2015
 Nine Months
Ended
September 30,
2016
CNG (1) 143.9
 182.6
 229.2
 61.1
 66.7
 168.5
 191.7
RNG (2) 10.5
 12.2
 8.8
 1.3
 0.7
 7.7
 2.3
LNG 60.0
 70.3
 70.5
 18.2
 17.1
 54.0
 50.9
Total 214.4

265.1

308.5

80.6
 84.5
 230.2
 244.9
               
Gasoline gallon equivalents
delivered (in millions)
 
Year Ended
December 31,
2013
 
Year Ended
December 31,
2014
 
Year Ended
December 31,
2015
 Three Months
Ended
September 30,
2015
 Three Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2015
 Nine Months
Ended
September 30,
2016
O&M 108.7
 137.3
 159.3
 41.5
 45.7
 118.7
 130.4
Fuel (1) 86.4
 108.2
 130.1
 33.3
 32.3
 95.0
 96.8
Fuel and O&M (3) 19.3
 19.6
 19.1
 5.8
 6.5
 16.5
 17.7
Total 214.4
 265.1
 308.5
 80.6
 84.5
 230.2
 244.9
               
2017:
Other Operating data (in thousands) 
Year Ended
December 31,
2013
 
Year Ended
December 31,
2014
 
Year Ended
December 31,
2015
 Three Months
Ended
September 30,
2015
 Three Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2015
 Nine Months
Ended
September 30,
2016
Gross margin $127,713
 $120,153
 $125,835
 25,534
 35,159
 69,731
 110,983
Net income (loss) attributable to Clean Energy Fuels. Corp (4) $(66,968) $(89,659) $(134,242) $(23,119) $(12,628) $(84,228) $(8,270)
Gasoline gallon equivalents
delivered (in millions)
 
Year Ended
December 31,
2014
 
Year Ended
December 31,
2015
 
Year Ended
December 31,
2016
 Three Months
Ended
September 30,
2016
 Three Months
Ended
September 30,
2017
 Nine Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2017
CNG (1) 182.6
 229.2
 259.2
 66.7
 73.5
 191.7
 213.1
RNG (2) 12.2
 8.8
 3.0
 0.7
 0.7
 2.3
 1.9
LNG 70.3
 70.5
 66.8
 17.1
 17.3
 50.9
 50.0
Total 265.1

308.5

329.0

84.5
 91.5
 244.9
 265.0
               

Gasoline gallon equivalents
delivered (in millions)
 
Year Ended
December 31,
2014
 
Year Ended
December 31,
2015
 
Year Ended
December 31,
2016
 Three Months
Ended
September 30,
2016
 Three Months
Ended
September 30,
2017
 Nine Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2017
O&M 137.3
 159.3
 176.6
 45.7
 53.2
 130.4
 150.2
Fuel (1) 108.2
 130.1
 128.5
 32.3
 32.3
 96.8
 96.7
Fuel and O&M (3) 19.6
 19.1
 23.9
 6.5
 6.0
 17.7
 18.1
Total 265.1
 308.5
 329.0
 84.5
 91.5
 244.9
 265.0
               
Other operating data (in millions) 
Year Ended
December 31,
2014
 
Year Ended
December 31,
2015
 
Year Ended
December 31,
2016
 Three Months
Ended
September 30,
2016
 Three Months
Ended
September 30,
2017
 Nine Months
Ended
September 30,
2016
 Nine Months
Ended
September 30,
2017
Station construction cost of sales $56.3
 $32.3
 $57.0
 $12.3
 $11.6
 $41.3
 $31.3
Gross margin (4) (5) $120.2
 $125.8
 $147.1
 $35.2
 $8.5
 $111.0
 $60.8
Net loss attributable to Clean Energy Fuels. Corp (4) $(89.7) $(134.2) $(12.2) $(12.6) $(94.1) $(8.3) $(50.9)
 
(1) As noted above, amounts include our proportionate share of the GGEs sold as CNG by our joint venture MCEP and our former joint venture in Peru.MCEP. GGEs sold by thesethis joint venturesventure were 2.1 million, 0.0 million, 0.4 million, and 0.40.5 million, for the years ended December 31, 2013, 2014, 2015, and 2015, respectively. Our joint venture MCEP had volumes of2016, respectively, 0.1 million and 0.1 million for the three months ended September 30, 20152016 and 2016,2017, respectively, and 0.30.4 million and 0.4 million for the nine months ended September 30, 20152016 and 2016,2017, respectively.
(2) Represents RNG sold as non-vehicle fuel. RNG sold as vehicle fuel, also known as Redeem™, is included in CNG and LNG.
(3)Represents gasoline gallon equivalents at stations where we provide both fuel and O&M services.

(4)Includes the following amounts of revenue pursuant to a federal alternative fuels tax credit ("VETC"): $45.4 million,VETC: $28.4 million, $31.0 million, and $26.6 million for the years ended December 31, 2013, 2014, 2015, respectively; $0.0and 2016, respectively, $6.7 million and $6.7$0.0 million for the three months ended September 30, 20152016 and 2016,2017, respectively, and $0.0$19.6 million and $19.6$0.0 million for the nine months ended September 30, 20152016 and 2016,2017, respectively. See the discussion under “Operations—VETC”“Recent Developments—VETC Expiration” below.
(5)For the three months ended September 30, 2017, gross margin includes an inventory valuation provision of $13.2 million. See Recent Developments and Note 2 for more details.
Recent Developments
Asset Impairments, Other Charges, and Inventory Valuation Provision. During the three months ended September 30, 2017, we undertook an evaluation of our operations with the intent of minimizing and eliminating assets we believe are underperforming. As a result of this evaluation, we identified 42 fueling stations where the current and projected natural gas volume and profitability levels are not expected to be sufficient to support our investment in the fueling station assets, and we determined to close these stations by the end of 2017. We also reduced our workforce and took other steps to reduce overhead costs in the third quarter of 2017 as a result of this evaluation, in an effort to lower our operating expenses going forward. In addition, we are seeking a strategic partner and position our compressor business, Clean Energy Compression Corp. ("CECC"), to benefit from consolidation in the natural gas compressor sector, in an effort to increase its scale and reach and improve the financial prospects of our investment.

As a result of these decisions and the steps taken to implement them, we determined that impairment indicators were present for CECC’s assets and the closed station assets, and we recorded asset impairment charges of $32.3 million related to CECC and $20.4 million related to the station closures in the three and nine months ended September 30, 2017. We also recorded during these periods an additional $4.9 million of other charges relating to the station closures, consisting of lease termination fees, write-offs of deferred losses, and an increase in asset retirement obligations. In addition, we incurred $3.0 million during these periods related to our workforce reduction and $13.2 million during these periods related to a non-cash inventory valuation provision. As a result of these steps, we incurred, on a pre-tax basis, aggregate cash and non-cash charges of $73.8 million during the three and nine months ended September 30, 2017. For more information, see Note 2 to the condensed consolidated financial statements included in this report.

Purchase of Natural Gas Heavy -Duty Trucks. On July 25, 2017, we entered into an arrangement to purchase used natural gas heavy -duty trucks by December 29, 2017, with the intention of selling the trucks to our customers. As of September 30, 2017, this arrangement represented an outstanding commitment to purchase 136 natural gas heavy -duty trucks valued at $8.8 million.
NG Advantage. In June 2017, our subsidiary NG Advantage, LLC (“NG Advantage”) entered into an arrangement with one of its customers for the purchase, sale and transportation of CNG over a five-year period. The arrangement is customary and ordinary course, and provides for the payment by the customer of a nonrefundable amount of $13.36 million to reserve a specified

volume of CNG transportation capacity under the arrangement. This amount was paid to NG Advantage in two installments, with $8.35 million paid on July 3, 2017 and $5.01 million paid on October 2, 2017.

Contribution of Milton CNG Station. On July 14, 2017, we contributed to NG Advantage all of its right, title and interest in and to a CNG station located in Milton, Vermont. We had purchased this CNG station from NG Advantage in October 2014 in connection with our initial investment in NG Advantage, and at that time, we entered into a lease agreement with NG Advantage to lease the station back to NG Advantage. This lease agreement was terminated contemporaneously with the contribution of the station to NG Advantage in July 2017. As consideration for the contribution, NG Advantage issued to us Series A Preferred Units with an aggregate value of $7.5 million. The Series A Preferred Units provide for an accrued return in the event of a liquidation event with respect to NG Advantage and will convert into common units of NG Advantage if and when it completes a future equity financing that satisfies certain specified conditions, but the Series A Preferred Units do not, in themselves, increase our controlling interest in NG Advantage. As a result, following the contribution, our controlling interest in NG Advantage remains at 53.3%.
Termination of ATM Program. On May 31, 2017, we terminated our equity distribution agreement (the “Sales Agreement”) with Citigroup Global Markets Inc. (“Citigroup”), as sales agent and/or principal. The Sales Agreement was terminable at will upon written notification by us with no penalty. Pursuant to the Sales Agreement, we were entitled to issue and sell, from time to time, through or to Citigroup shares of our common stock having an aggregate offering price of up to $200.0 million in an “at-the-market” offering program (the “ATM Program”). The ATM Program commenced on November 11, 2015 when we and Citigroup entered into the original equity distribution agreement, which was amended and restated on September 9, 2016 and again on December 21, 2016 prior to its termination.

Asset Sale. On February 27, 2017, Clean Energy Renewable Fuels ("Renewables"), our subsidiary, entered into an asset purchase agreement (the “APA”) with BP Products North America, Inc. (“BP”), pursuant to which Renewables agreed to sell to BP certain assets relating to its RNG production business (the “Asset Sale”), consisting of Renewables’ two existing RNG production facilities, Renewables’ interest in the RNG Ventures and Renewables’ third-party RNG supply contracts (the “Assets”). The Asset Sale was completed on March 31, 2017 for a sale price of $155.5 million, plus BP assumed the obligations under the Canton Bonds (as defined in Note 13 to the condensed consolidated financial statements included in this report) which totaled $8.8 million as of March 31, 2017.

On March 31, 2017, BP paid Renewables $30.0 million in cash and delivered to Renewables a promissory note with a principal amount of $123.5 million, which was paid in full on April 3, 2017. In addition, on June 22, 2017, BP paid Renewables an additional $2.0 million related to the determination of certain post-closing adjustments. Renewables recognized a gain of $69.9 million as of September 30, 2017 from the Asset Sale. Pursuant to the APA, the valuation date of the Asset Sale was January 1, 2017, and the APA included certain adjustments to the purchase price to reflect a determination of the amount of cash accumulated by Renewables from the valuation date to the closing date, net of permitted cash outflows. Control of the Assets was not transferred until the Asset Sale was completed on March 31, 2017. Accordingly, the full operating results of Renewables are included in the condensed consolidated statement of operations through March 31, 2017.

In addition, under the APA, BP is required, following the closing of the Asset Sale, to pay Renewables up to an additional $25.0 million in cash over a five-year period if certain performance criteria relating to the Assets are met.

We incurred $3.7 million in transaction fees in connection with the Asset Sale, and paid all such fees in the nine months ended September 30, 2017. Also, we paid $8.6 million in cash and issued 770,269 shares of common stock to holders of Renewables Option Awards (as defined and discussed below). The net proceeds from the Asset Sale, net of $1.0 million cash transferred to BP were $142.2 million.

Following completion of the Asset Sale, we are continuing to procure RNG from BP under a long-term supply contract and from other RNG suppliers, and resell such RNG through our natural gas vehicle fueling infrastructure as Redeem™, our RNG vehicle fuel. We collect royalties from BP on gas purchased from BP and sold as Redeem™ at our stations, which royalty is in addition to any payment obligation of BP under the APA.

Renewables Options. In September 2013, Renewables established the 2013 Unit Option Plan (the “Renewables Plan”) and granted unit option awards thereunder (the “Renewables Option Awards”) to certain of its service providers. In connection with the closing of the Asset Sale, all holders of outstanding Renewables Option Awards entered into a surrender agreement with us and Renewables, pursuant to which (i) all Renewables Option Awards held by holders who were not members of Renewables’ Board of Managers were surrendered and canceled in full in exchange for, upon the closing of the Asset Sale and Renewables’ receipt of any future cash payment pursuant to the terms of the APA, a cash payment in an amount determined based on such holder’s percentage ownership of Renewables following a cashless “net exercise” of such holder’s Renewables Option Awards, and (ii) all Renewables Option Awards held by members of Renewables’ Board of Managers were surrendered and canceled in

full in exchange for, upon the closing of the Asset Sale and Renewables’ receipt of any future cash payment pursuant to the terms of the APA, awards of shares of our common stock (the “Company Stock Awards”). The number of shares of our common stock subject to each Company Stock Award was calculated by dividing the cash payment to which the applicable holder would have been entitled as described in (i) above by the closing price of our common stock on March 31, 2017, the closing date of the Asset Sale. All Company Stock Awards were granted under our 2016 Performance Incentive Plan and are fully vested upon grant, and the shares subject to such awards are freely tradable upon issuance, subject to applicable securities laws relating to shares held by our affiliates.
Debt Repurchase. In February 2017, we purchased from one of our directors and significant stockholders, T. Boone Pickens ("Mr. Pickens"), the 7.5% Convertible Note due July 2018 having an outstanding principal amount of $25.0 million held by Mr. Pickens for a cash purchase price of $21.75 million. See Note 13 to the condensed consolidated financial statements included in this report for more information about our outstanding debt.
VETC Expiration. On December 31, 2016, the VETC alternative fuels tax credit expired and ceased to be available and may not be available in any subsequent period. Under VETC, we were eligible to receive credits of $0.50 per gasoline gallon equivalent of CNG and $0.50 per diesel gallon equivalent of LNG that we sold as a vehicle fuel from January 1, 2016 through December 31, 2016.
Business Risks and Uncertainties
Our business and prospects are exposed to numerous risks and uncertainties. For more information, see “Risk Factors” in Part II, Item 1A of this report.
Key Trends
Market for Natural Gas - Demand and Pricing.Gas. CNG and LNG are generally less expensive than gasoline and diesel on an energy equivalent basis and,basis. Additionally, according to studies conducted by the California Air Resources Board ("CARB") and Argonne National Laboratory, a research laboratory operated by the University of Chicago for the United StatesU.S. Department of Energy, CNG and LNG are cleaner than gasoline and diesel fuel. According to the U.S. Energy Information Administration, demand for natural gas fuels in the United States has increased in recent years and is expected to continue to increase. We believe this growth in demand is attributable primarily to the higher prices of gasoline and diesel relative to CNG and LNG, during much of this period, increasingly stringent environmental regulations affecting vehicle fleets and increased availabilitysupply of natural gas.
In the recent past,Since approximately mid-2014, however, the prices of oil, gasoline, diesel and natural gas have been significantly lower and volatile, and these trends of lower prices and volatility may continue. TheseWe believe these conditions have resultedcontributed to slower and more limited growth in lower revenue levelsthe demand for natural gas as a vehicle fuel, both in general and in certain periods due to a decreasedof our key markets, such as heavy-duty trucking, because the pricing advantage when comparing natural gas prices to diesel and gasoline prices andhas decreased. We believe this decreased pricing advantage has also contributed to our lower revenue levels in recent periods. In addition, these conditions have also caused us to reduce the reduced prices we have been charging our customers for CNG and LNG. As a result of the lower prices,LNG in some instances, which has reduced our profit margins were reduced, butmargins. Further, to a lesser degree, due to reduced natural gas commodity costs. To the extent these conditions have contributed to curtailed demand or slowed growth in the market for natural gas as a vehicle fuel, we believe they have also contributed to decreases in compressor sales and station construction activity in certain periods, as the success of these aspects of our operations is dependent upon the success of the natural gas vehicle fuels market generally. Due to these and other factors, during the three months ended September 30, 2017, we identified for closure certain underperforming stations in our fueling station network, which resulted in an impairment of the associated assets and certain other cash and non-cash charges, and we also determined the assets related to our compressor business were impaired. See "Our Performance" below for more information. In addition, we believe these factors have materially contributed to the volatility and overall decline in our stock price and market capitalization in recent years, which has and could in the future lead to decreased cash flows and/or indications of asset or goodwill impairment. If these volatile and lower-pricinglow price conditions and other uncertainties persist, our financial results and stock price may continue to be adversely affected.

Our Performance. In light of continuing low oil prices and the current state of natural gas vehicle adoption as described above, during the three months ended September 30, 2017, we took steps to minimize and eliminate assets we believe are underperforming in an effort to better align our activities with current and anticipated natural gas fueling demand, and to try to lower our operating expenses going forward by streamlining our operations. These steps included a workforce reduction and other measures to reduce overhead costs, which resulted in cash severance costs and certain non-cash stock-based compensation charges; our decision to close certain of our natural gas fueling stations by the end of 2017, which resulted in an impairment of these station assets and certain other cash and non-cash charges; a determination that the assets of CECC, which operates our natural gas fueling compressor business, were impaired, which resulted in a non-cash charge; and positioning CECC to benefit from consolidation in the natural gas compressor sector. See "Recent Development" above and Note 2 to the condensed consolidated financial statements included in this report for more information.

Our gross revenue is mostly comprisedconsists of volume related-related revenue, compressor and other equipment sales, station construction sales, sales of tradable credits and historically, VETC revenue. Our revenue can vary between periods due to a variety of factors, including, among others, the amount and timing of station construction sales, sales of RINs and LCFS Credits, recognition of any other government credits and, compressor and other equipment sales, recognition of VETCsales; fluctuations in commodity costs; and other credits as well as natural gas prices and sale activity. Our volume-related revenues,revenue, which areis further discussed below, increased across all of these periods,from 2014 to 2016 due largely to the increase in gallons we delivered.delivered across this period; however, volume-related revenue declined in the three and nine months ended September 30, 2017 compared to the same periods in 2016, primarily due to decreased revenue from sales of RINs and LCFS Credits as a result of the Asset Sale. We expect this trend to continue.

Our cost of sales can also vary between periods due to a variety of factors, including fluctuations in commodity, costs of fuel, the amount and timing of compressor and other equipment sales and station construction sales, and natural gas priceslabor costs, fluctuations in compressor equipment costs; and sale activity.the other factors that impact our revenue levels described above.

In addition, our performance in certain recent periods has been materially affected by certain non-cash gains relating to particular transactions or events. For example, our results for the nine months ended September 30, 2016 and 2017 were positively affected by gains related to repurchases and retirements of our outstanding convertible debt, and our results for the nine months ended September 30, 2017 were also positively affected by the gain from the Asset Sale. These or other gains or losses may not recur regularly, in the same amounts or at all in future periods and, with respect to non-cash gains and losses, do not impact our liquidity.

See "Results of Operations" below for a further discussion of our performance.

Volume-Related Revenues.Revenue. The amount of CNG, LNG and RNG GGEs we delivered increased by 43.9%24.1% from 20132014 to 20152016 and by 6.4%8.2% from the first nine months of 20152016 compared to the same period in 2016.2017.

TheIn particular, the amount of RNG we sell for vehicle fuel, which is delivered in the form of CNG or LNG and is distributed under the name Redeem™. The amount of Redeem vehicle fuel we delivered increased, has experienced rapid growth in recent years, increasing by 190.1% from 20.2 million GGEs in 2014 to 50.158.6 million GGEs in 2015, a 148% increase. Further, we delivered2016, and by 22.7% from 43.7 million GGEs of Redeem duringin the first nine months ended September 30,of 2016 compared to 36.053.6 million GGEs duringfor the nine months ended September 30, 2015, a 21.4% increase. same period in 2017.

We believe this demand for Redeem™ is largely attributable to its production ofthe lower greenhouse gas emissions thanthat it produces relative to gasoline and diesel.diesel, and we expect our Redeem™ business will continue to grow.

Our sales of increasing volumes of CNG, LNGWhen we sell natural gas and RNG for use as a vehicle fuel, has resulted inwe are eligible to generate RINs and LCFS Credits, which we then seek to sell to third parties. The following table summarizes our generation of increasing amountsrevenue from sales of RINs and LCFS Credits which, together within the increasing prices forperiods presented:
 Three Months Ended September 30, Nine Months Ended September 30,
(In millions)2016 2017 2016 2017
RIN Credits$7.0
 $3.8
 $20.0
 $17.2
LCFS Credits (1)4.3
 
 15.2
 2.9
Total$11.3
 $3.8
 $35.2
 $20.1
(1)We recognized no revenue from sales of LCFS Credits during the three months ended September 30, 2017 primarily because the majority of the LCFS Credits we had generated were sold to BP pursuant to the APA and we temporarily stopped sales of our remaining LCFS Credits due to restrictions imposed on our credit account pending completion of ongoing administrative review by CARB. We continue to generate LCFS Credits and we expect to recognize revenue from sales of such credits during the three months ending December 31, 2017. However, if CARB’s administrative review results in the retirement of any of our LCFS Credits or is otherwise unfavorable, we may be required to recognize a charge equal to the value of the retired credits or we may experience other negative effects.
Although we continue to generate revenue from the sale of RINs and LCFS Credits in connection with our continued sales of CNG, LNG and our Redeem™ RNG vehicle fuel, the amount of revenue we receive from sales of these credits has resulteddecreased as a result of our sale of certain of our former RNG assets in increased revenues associated with these credits. Historically, the Asset Sale, which has adversely affected our results of operations, in particular our volume -related revenue, and reduced our effective price per gallon. Pursuant to the terms of the APA, $5.1 million of revenue attributable to sales of RINs and LCFS Credits in the first quarter of 2017 served as an adjustment to the purchase price and was recorded as a reduction of the gain from the Asset Sale (see Note 3 to the condensed consolidated financial statements included in this report).


The markets for RINs and LCFS Credits have historically been volatile, and the prices for these credits have been subject to significant fluctuations.
Additionally, the value of RINs and LCFS Credits, and consequently the revenue levels we may receive from our sale of these credits, may be adversely affected by any changes to the federal and state programs under which such credits are generated and sold. For example, CARB recently raised the carbon intensity ratingIn addition, our ability to generate revenue from sales of the RNG we sell in California,these credits depends upon our strict compliance with these federal and state programs, which will reduce the amount of LCFS Credits we generate.
Our Stations. The number of fueling stations we owned, operated, maintained and/or supplied increased from 471 at January 1, 2013 to over 575 at September 30, 2016 (a 22.1% increase). Included in this number are all of the CNGcomplex and LNG fueling stations we own, operate, maintain or with which we have a fueling supply contract.

We have madecan involve a significant commitmentdegree of capitaljudgment. If the agencies that administer and other resourcesenforce these programs disagree with our judgments, otherwise determine we are not in compliance or conduct reviews of our activities, then our ability to buildgenerate or sell these credits could be temporarily restricted pending completion of reviews or as a nationwide network of natural gas truck friendly fueling stations, which we refer to as "America's Natural Gas Highway"penalty, permanently limited or "ANGH." At September 30, 2016, we had 39 completed ANGH stations that were not open for fueling operations. We expect to open such stations when we have sufficient customers to fuel at the locations,lost entirely, and we do not know when this will occur. We believe that growthcould also be subject to fines or other sanctions, any of heavy-duty truck customers depends, in part, on the development and adoption of natural gas engines that are well-suited for use by heavy-duty trucks, which has been slower and more limited than anticipated. If these customers do not develop and if we do not open these stations, we will continuecould force us to have substantial investments in assets that do not produce revenues equal to or greater than their costs. Additionally,

most of our ANGH stations were initially built to provide LNG, which typically costs more than CNG on an energy equivalent basis; however, because operators are adopting both LNG heavy-duty trucks and CNG heavy-duty trucks, we designed these stations to be capable of dispensing both fuels. Where we deem appropriate, we have been investing, and expect to continue to invest, additional capital in our ANGH stations to add CNG fueling. To help accelerate the adoption by heavy-duty truck fleets of natural gas, we have negotiated favorable CNG and LNG tank pricing from manufacturers, which we are passing through to our customers.
Recent Developments
On February 29, 2016, we entered into a loan and security agreement with, and issued a related promissory note to, PlainsCapital Bank ("Plains"), pursuant to which Plains agreed to lend us up to $50.0 million on a revolving basis for a term of one year (the "Credit Facility"). Simultaneously, we drew down $50.0 million under the Credit Facility, which we repaid in full as of September 30, 2016. On October 31, 2016, the Credit Facility's maturity date was extended from February 28, 2017 to September 30, 2018.
On March 1, 2016 and pursuant to the consent of the holders of our outstanding 7.5% convertible promissory notes due in August 2016 (the "SLG Notes"), we prepaid in cash an aggregate of $60.0 million in principal amount and $1.8 million in accrued and unpaid interest owed under the SLG Notes. Additionally, on July 14, 2016, we entered into separate privately negotiated exchange agreements with each holder of an SLG Note to exchange the outstanding principal amount of each SLG Note, totaling $85.0 million for all SLG Notes, and all accrued and unpaid interest thereon, totaling $0.2 million for all SLG Notes, for an aggregate of 14,000,000 shares of our common stock and $38.2 million in cash. We recognized a loss of $0.9 million for the nine months ended September 30, 2016 related to the settlement of the SLG Notes. The repurchased and exchanged SLG Notes have been terminated and canceled in full and we have no further obligations under the SLG Notes.
Our board of directors has authorized and approved the use of up to $50.0 million to opportunistically purchase our outstanding 5.25% Convertible Senior Notes due 2018 (the "5.25% Notes")credits in the open market in accordance with the terms of the indenture governing the 5.25% Notes. Pursuant to this approval, in the nine months ended September 30, 2016,cover any credits we paid an aggregate of $24.9 million in cashhave contracted to repurchase andsell, retire $45.4 million in aggregate principal amount of 5.25% Notes, together with accrued and unpaid interest thereon. Additionally, pursuant to a privately negotiated exchange agreement with certain holders of the 5.25% Notes, on May 4, 2016, we issued an aggregate of 6,265,829 shares of our common stock in exchange for an aggregate principal amount of $25.0 million of 5.25% Notes held by such holders, together with accrued and unpaid interest thereon. Our repurchase and exchange of 5.25% Notes in the nine months ended September 30, 2016 resulted in a total gain of $26.3 million recorded during the period. All repurchased and exchanged 5.25% Notes have been surrendered to the trustee for such notes and canceled.
See Note 10 to the condensed consolidated financial statements included in this report for additional information about our outstanding debt.
On September 9, 2016, we entered into an amended and restated equity distribution agreement with Citigroup Global Markets Inc. ("Citigroup"), as sales agent and/or principal, pursuant to whichcredits we may issue and sell, from time to time, throughhave generated but not yet sold, or to Citigroup, shares of our common stock having an aggregate offering price of up to $110.0 million in an "at-the-market" offering program (the "ATM Program").eliminate or reduce a significant revenue stream.

Anticipated Future Trends
Although natural gas continues to be less expensive than gasoline and diesel in most markets, the price of natural gas vehicle fuel has been significantly closer to the prices of gasoline and diesel in recent years as a result ofdue in part to lower oil prices, thereby reducing the price advantage of natural gas as a vehicle fuel. We anticipate that, over the long term, the prices for gasoline and diesel will continue to be higher than the price of natural gas as a vehicle fuel and will increase overall, which would improve the cost savings of natural gas as a vehicle fuel compared to gasoline and diesel. It is uncertain whether the prices for gasoline and diesel will increase from their current levels, and we expect that adoption of natural gas as a vehicle fuel and growth in our customer base and revenue will be negatively affected while the low oil and diesel price conditions continue. OurThis belief that natural gas will continue, over the long term, to be a cheaper vehicle fuel than gasoline or diesel is based in large part on the growth in recent years of natural gas production in the United States, as well as increasingly stringent environmental regulations affecting vehicle fleets.fleets, which we believe drives the market for alternative vehicle fuels generally.

It is uncertain, however, whether and when the prices for gasoline and diesel will increase, and we expect that adoption of natural gas as a vehicle fuel and growth in our customer base and revenue will be negatively affected while oil and diesel prices remain low. Other factors also create potential uncertainties about the future market for natural gas as a vehicle fuel, including growing favor by lawmakers, regulators, other policymakers, environmental organizations or other powerful groups for non-natural gas fuels and vehicles, including long-standing support for gasoline and diesel-powered vehicles and growing favor for electric and/or hydrogen-powered vehicles, and the availability and effect on our business of environmental and other regulations, programs or incentives. These and other factors make it challenging to accurately predict natural gas vehicle fuel demand, in general and in any specific geographic and customer markets. As a result, our timing and level of investment in particular markets may not be consistent with any growth in demand in these markets.

We have made efforts we believe will better align our activities and assets with current and anticipated market demand. For instance, we plan to close 42 natural gas fueling stations by the end of 2017 and are positioning our compressor business to benefit from consolidation in the natural gas sector. We expect these actions will have a number of effects on our financial condition and performance, including primarily decreased revenue and decreased costs from the closed assets and our related operations in the near term. We also anticipate the measures we implemented in the third quarter of 2017 to reduce our operating costs, including a workforce reduction and other measures to reduce overhead costs, will contribute to decreased expenses going forward, particularly selling, general and administrative expenses.

We believe natural gas fuels are well-suited for use by vehicle fleets that consume high volumes of fuel, refuel at centralized locations or along well-defined routes and/or are increasingly required to reduce emissions. As a result, we believe there will be growth in the consumption of natural gas as a vehicle fuel among vehicle fleets, and our goal is to capitalize on this trend if and to the extentwhen it materializes, and to enhance our leadership position in these markets.materializes. Our business plan calls for expanding our sales of natural gas fuelsvehicle fuel in the markets in which we operate, including heavy-duty trucking, airports, refuse, public transit,

government fleets and industrial and institutional energy users, and pursuing additional markets as opportunities arise. Additionally, we expect that the lower greenhouse gas emissions produced byassociated with our RedeemRedeem™ vehicle fuel will result in continued increased demand for andthis fuel, resulting in our delivery of increasing volumes of RedeemRedeem™ to our vehicle fleet customers in the future.customers. If these projections materialize and our business grows as we anticipate, then our operating costs and capital expenditures may increase, primarily from the anticipated expansion of our station network and RNG production capacity and additional investments in ANGH stations to add CNG fueling, as well as the logistics of delivering more natural gas fuel to our customers.could increase. We also may pursue strategic partnerships or similar arrangements or seek to invest in or acquire assets and/or businesses that are in the natural gas fueling infrastructure, or RNG production business, which may require us to spend additional capital.

Although weWe expect competition in the market for natural gas vehicle fuel to remain steady in the near-term, but we expect competition in the alternativevehicle fuels market generally to increase. Any such increased competition wouldmay reduce our customer base and revenue and may lead to amplified pricing pressure, reduced operating margins and fewer expansion opportunities.

LiquiditySeveral factors create potential uncertainties relating to the future market for natural gas as a vehicle fuel. These factors include growing favor by lawmakers, regulators, other policymakers, environmental organizations or other powerful groups for non-natural gas fuels and Capital Resources
Historically,vehicles, including long-standing for gasoline and diesel-powered vehicles and growing favor for electric and/or hydrogen-powered vehicles, and the availability and effect on our principal sourcesbusiness of liquidity have consisted of cash on hand, cash provided by our operations, including, if available, grants, VETCenvironmental and other credits,regulations, programs

or incentives. Subsequent to December 31, 2016, our stock price has declined due to adverse macroeconomic conditions surrounding the energy industry which could also lead to decreased cash flows which may indicate the carrying value of our goodwill or long lived assets is impaired. As a result of the recent volatility of our market capitalization and possible decrease in cash provided by financing activitiesflows, it is possible that our goodwill or long lived assets could become impaired, which could result in a material charge and salesadversely affect our results of assets.
Our business plan calls for approximately $25.5 million in capital expenditures for all of 2016, primarily related to the construction of CNG and LNG fueling stations (including adding CNG fueling to ANGH stations) and the purchase of CNG trailers by our subsidiary, NG Advantage, LLC ("NG Advantage") and to a lesser extent, LNG plant maintenance costs and RNG plant construction and maintenance costs. Additionally, we had total indebtedness of $355.5 million in principal amount as of September 30, 2016.
We may also elect to invest additional amounts in companies, assets or joint ventures in the natural gas fueling infrastructure, vehicle or services industries, including RNG production, or use capital for other activities or pursuits. We will need to raise additional capital to fund any capital expenditures, investments or debt repayments that we cannot fund through available cash or cash provided by our operations or that we cannot fund through other sources, such as with our common stock. We may not be able to raise capital when needed on terms that are favorable to us or our stockholders, or at all. Any inability to raise capital may impair our ability to build new stations, develop natural gas fueling infrastructure, invest in strategic transactions or acquisitions or repay our outstanding indebtedness and may reduce our ability to grow our business and generate sustained or increased revenues.operations. See "Liquidity and Capital Resources" below.
Business Risks and Uncertainties
Our business and prospects are exposed to numerous risks and uncertainties. For more information, see “Risk Factors” in Part II, Item 1A of this report.
Operations
The following discussion describes the various components of our operations.
CNG Sales
We sell CNG through fueling stations and by transporting it to customers that do not have direct access to a natural gas pipeline. CNG fueling station sales are made through stations located on our customers’ properties and through our network of public access fueling stations. At these CNG fueling stations, we typically procure natural gas from local utilities or third-party marketers and then compress and dispense it into our customers' vehicles. Our CNG fueling station sales are made primarily through contracts with our customers. Under these contracts, pricing is principally determined on an index-plus basis, which is calculated by adding a margin to the local index or utility pricereport for natural gas. As a result, CNG sales revenues determined by an index-plus methodology increase or decrease as a result of an increase or decrease in the price of natural gas. The remainder of our CNG fueling station sales are on a per fill-up basis at prices we set at public access stations based on prevailing market conditions. We purchase some natural gas for CNG sales from third-parties under “take or pay” contracts that require us to purchase minimum volumes of natural gas.
LNG Production and Sales
We obtain LNG from our own plants as well as through relationships with suppliers. We own and operate LNG liquefaction plants near Houston, Texas and Boron, California.
We sell LNG on a bulk basis to fleet customers, that often own and operate their fueling stations, and we also sell LNG to fleet and other customers at our network of public access fueling stations. We also sell LNG for non-vehicle purposes, including toadditional information.

customers who use LNG in oil fields or for industrial or utility applications. In 2015 and the first nine months of September 30, 2016, we purchased 43% and 44%, respectively, of our LNG from third-party producers, and we produced the remainder of our LNG at our liquefaction plants in Texas and California. We purchase some LNG from third-parties under “take or pay” contracts that require us to purchase minimum volumes of LNG.
We deliver LNG via our fleet of 84 tanker trailers to fueling stations, where it is stored and dispensed in liquid form into vehicles. As with our CNG customer contracts, we sell LNG through supply contracts that are priced on an index-plus basis, such that LNG sales revenues from these contracts increase or decrease as a result of an increase or decrease in the price of natural gas. We also sell LNG on a per fill-up basis at prices we set at public access stations based on prevailing market conditions. LNG generally costs more than CNG, as LNG must be liquefied and transported.
VETC
Under separate pieces of U.S. federal appropriations legislation from October 1, 2006 through December 31, 2014, we were eligible to receive a federal alternative fuels tax credit (“VETC”) of $0.50 per gasoline gallon equivalent of CNG and $0.50 per liquid gallon of LNG that we sold as vehicle fuel. In December 2015, Congress passed the Consolidated Appropriations Act that included the passage of an alternative fuel tax credit which we continue to refer to as VETC. The credit was made retroactive to January 1, 2015 and extended through December 31, 2016, except that the alternative fuel tax credit for LNG sold as a vehicle fuel in 2016 was changed to be based on the diesel gallon equivalent of LNG sold rather than the liquid gallon of LNG sold. As a result, we were eligible to receive a credit of $0.50 per gasoline gallon equivalent of CNG sold as a vehicle fuel in 2015 and 2016, $0.50 per liquid gallon of LNG sold in 2015 and $0.50 per diesel gallon equivalent of LNG sold in 2016. The diesel gallon equivalent for the VETC credit for LNG sales in 2016 is expected to result in lower revenues than the VETC credit for LNG sales in 2015.
Based on the service relationship with our customers, either we or our customers claim the credit. We recorded these tax credits as revenues in our condensed consolidated statements of operations, as the credits are fully payable and do not need to offset tax liabilities to be received. As such, the credits are not deemed income tax credits under the accounting guidance applicable to income taxes. In addition, we believe the credits are properly recorded as revenue because we often incorporate the tax credits into our pricing with our customers, thereby lowering the actual price per gallon we charge.
VETC revenues for 2015, totaling $31.0 million, were all recognized in December 2015. VETC revenues for the three and nine month period ended September 30, 2016 totaled $6.7 million and $19.6 million, respectively.

O&M Services
We generate revenues from our performance of O&M services for CNG and LNG fueling stations that we do not own. For these services we generally charge a fixed fee or a per-gallon fee based on the volume of fuel dispensed at the station. We include the volume of fuel dispensed at the stations at which we provide O&M services in our calculation of aggregate gasoline gallon equivalents delivered.
Station Construction and Engineering
We generate revenues from designing and constructing fueling stations, facility modifications, and selling or leasing some of the stations to our customers. For these projects, we typically act as the general contractor or supervise qualified third-party contractors. We also offer assessment, design and modification solutions to provide operators with code-compliant service and maintenance facilities for natural gas vehicle fleets. For example, our NGV Easy Bay™ product is a natural gas vapor leak barrier developed specifically for natural gas vehicle facilities. We charge construction or other fees or lease rates based on the size and complexity of the project.
RNG Production and Sales
Our subsidiary, Clean Energy Renewables, owns RNG production facilities located at Republic Services landfills in Canton, Michigan and North Shelby, Tennessee. Clean Energy Renewables has entered into long-term fixed-price sale contracts for the majority of the RNG that we expect these facilities to produce over the next seven years. We are seeking to expand our RNG business by pursuing additional RNG production projects, either on our own or with project partners. We sell most of the RNG we produce through our natural gas fueling infrastructure for use as a vehicle fuel. In addition, we purchase RNG from third-party producers, and sell that RNG for vehicle fuel use through our fueling infrastructure. The RNG we sell for vehicle fuel use is distributed under the name Redeem™.


Natural Gas Fueling Compressors
Clean Energy Compression manufactures, sells and services non-lubricated natural gas fueling compressors and related equipment for the global natural gas fueling market. Clean Energy Compression is headquartered near Vancouver, British Columbia, has an additional manufacturing facility near Shanghai, China and has sales and service offices in Bangladesh, Colombia, Peru and the United States.
Sales of RINs and LCFS Credits
We generate RIN Credits when we sell RNG for use as a vehicle fuel in the United States, and we generate LCFS Credits when we sell RNG and conventional natural gas for use as a vehicle fuel in California and Oregon. We can sell these credits to third parties who need the RINs and LCFS Credits to comply with federal and state requirements. Generally, the amount of RINS and LCFS Credits we generate increases as we sell higher volumes of natural gas as a vehicle fuel, but the amount of these credits that we sell and our revenues from these sales can vary depending on the market for these credits, which has historically been volatile and subject to significant price fluctuations, and changes to applicable regulations.
During the three months ended September 30, 2015, we realized $2.4 million and $2.3 million in revenue from the sale of RIN Credits and LCFS Credits, respectively. During the three months ended September 30, 2016, we realized $7.0 million and $4.3 million in revenue from the sale of RIN Credits and LCFS Credits, respectively. During the nine months ended September 30, 2015, we realized $7.7 million and $4.4 million in revenue from the sale of RIN Credits and LCFS Credits, respectively. During the nine months ended September 30, 2016, we realized $20.0 million and $15.2 million in revenue from the sale of RIN Credits and LCFS Credits, respectively. The markets for RINs and LCFS Credits are volatile, and the prices for such credits are subject to significant fluctuations. Further, the value of RINs and LCFS Credits will be adversely affected by any changes to the federal and state programs under which such credits are generated and sold.
Vehicle Acquisition and Finance
We offer vehicle finance services, including loans and leases, to help our customers acquire natural gas vehicles. As appropriate, we apply for and receive federal and state incentives associated with natural gas vehicle purchases and pass these benefits through to our customers. For 2015 and through September 30, 2016, we have not generated significant revenue from vehicle financing activities.
Debt Compliance
Certain of the agreements governing our outstanding debt, which are discussed in Note 10,13 to our condensed consolidated financial statements included in this report, have certain non-financial covenants with which we must comply. As of September 30, 2016,2017, we were in compliance with all of these covenants.
Risk Management Activities
Our risk management activities are discussed in the MD&A of our 20152016 Form 10-K. In the threenine months ended September 30, 2016,2017, there were no material changes to our risk management activities.
Critical Accounting Policies
We believe the following critical accounting policies affect our more significant judgments and estimates used in the preparation of our condensed consolidated financial statements.

Revenue recognition;
Impairment of goodwill and long-lived assets;
Income taxes; and
Fair value estimatesestimates.

Our critical accounting policies and estimates are discussed in the MD&A of our 20152016 Form 10-K. For the nine months ended September 30, 2016,2017, there were no material changes to our critical accounting policies except for the following changes to our Revenue Recognition policy pertaining to station construction sales.policies.

Beginning January 1, 2016, we began using the percentage of completion method to recognize revenue for station construction projects using the cost-to-cost method. Under this method, we estimated the percentage of completion of a project based on the costs incurred to date for the associated contract in comparison to the estimated total costs for such contract at completion. Historically, we recognized revenue on station construction projects using the completed-contract method because it did not have a reliable means to make estimates of the percentage of the contract completed. Under the completed contract method, the construction projects were considered substantially complete at the earlier of customer acceptance of the fueling station or the

time when fuel dispensing activities at the station began. The sale of compressors and related equipment continues to be recognized under the percentage of completion method as in previous periods.     

Effective January 1, 2016, we implemented a cost tracking system that provides for a detailed tracking of costs incurred on its station construction projects on a project by project basis. We also changed related accounting activities and processes to timely identify and monitor costs. As a result of this implementation, we are able to make reliable estimates as to the percentage of a project that is complete at the end of each reporting period.

Station construction contracts are generally short-term, except for certain larger and more complex stations, which can take up to 24 months to complete. Management evaluates the performance of contracts on an individual contract basis. Contract price and cost estimates are reviewed periodically as work progresses and adjustments proportionate to the percentage of completion are reflected in contract revenues in the reporting period when such estimates are revised.

The nature of accounting for contracts is such that refinements of estimates to account for changing conditions and new developments are continuous and characteristic of the process. Many factors that can affect contract profitability may change during the performance period of a contract, including differing site conditions, the availability of skilled contract labor, the performance of major suppliers and subcontractors, and unexpected changes in material costs. Changes to these factors may result in revisions to costs and income, which are recognized in the period in which the revisions become known. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses become known.

We consider unapproved change orders to be contract variations for which the customer has approved the change of scope but an agreement has not been reached as to an associated price change. Change orders that are unapproved as to both price and scope are evaluated as claims. Claims have historically been insignificant.

Recently Issued and Adopted Accounting Standards
For a description of recently issued and adopted accounting standards, see Note 1619 to the condensed consolidated financial statements included in this report.

Results of Operations
Three Months Ended September 30, 20152016 Compared to Three Months Ended September 30, 20162017     
The table below presents our results of operations as a percentage of total revenue and the narrative that follows provides a detailed discussion of certain line items for the periods presented.
Three Months Ended September 30, Three Months Ended September 30, 
2015 2016 2016 2017 
Statement of Operations Data: 
  
  
  
 
Revenue: 
  
  
  
 
Product revenues83.8 % 87.1 % 
Service revenues16.2
 12.9
 
Total revenues100.0

100.0
 
Product revenue87.1 % 82.7 % 
Service revenue12.9
 17.3
 
Total revenue100.0

100.0
 
Operating expenses: 
  
  
  
 
Cost of sales (exclusive of depreciation and amortization shown separately below): 
  
  
  
 
Product cost of sales64.3
 57.2
 57.2
 64.7
 
Service cost of sales8.0
 6.6
 6.6
 8.9
 
Gain from change in fair value of derivative warrants(0.5) 0.0
 
Inventory valuation provision
 16.1
 
Selling, general and administrative30.1
 26.7
 26.7
 30.3
 
Depreciation and amortization15.2
 15.3
 15.3
 17.2
 
Asset impairments and other charges
 74.2
 
Total operating expenses117.1

105.8

105.8

211.4

Operating loss(17.1) (5.8) (5.8) (111.4) 
Gain (loss) from extinguishment of debt, net
 (0.7) 
Interest expense, net(11.0) (6.5) 
Interest expense(6.6) (5.2) 
Interest income0.1
 0.6
 
Other income (expense), net2.9
 (0.1) (0.1) 0.0
 
Loss from equity method investments(0.2) 0.0
 0.0
 0.0
 
Gain (loss) from extinguishment of debt(0.7) 
 
Gain from sale of certain assets of subsidiary
 
 
Loss before income taxes(25.4)
(13.1)
(13.1)
(116.0)
Income tax benefit (expense)0.3
 (0.4) (0.4) 0.1
 
Net loss(25.1)
(13.5)
(13.5)
(115.9)
Loss from noncontrolling interest0.1
 0.4
 
Loss attributable to noncontrolling interest0.4
 0.9
 
Net loss attributable to Clean Energy Fuels Corp.(25.0)%
(13.1)%
(13.1)%
(115.0)%
Revenue.    Revenue increaseddecreased by $4.7$15.2 million to $97.0$81.8 million in the three months ended September 30, 2016, 2017, from $92.3$97.0 million in the three months ended September 30, 2015.2016. This increasedecrease was primarily due to increased volumes, increasedthe expiration of VETC in addition to lower volume -related revenue and station construction sales and increased VETC revenues, partially offset by loweran increase in compressor sales.revenue.
Volume related revenues increased-related revenue decreased by $3.4$8.2 million between periods primarily due to reduced revenue received from sales of RINs and LCFS Credits, due in large part to the effects of the Asset Sale and, for the three months ended September 30, 2017, the impact of temporarily stopping sales of LCFS Credits due to restrictions imposed on our LCFS Credit account. See "Key Trends" and Note 3 to the condensed consolidated financial statements included in this report for more information about RINs and LCFS Credits and the Asset Sale, respectively. The decrease in volume -related revenue between periods was partially offset by an increase of 3.97.0 million gallons delivered, which provided approximately $3.2 million of increased revenue. delivered.

This increase in gallons delivered was due to a 5.66.8 million and 0.2 million gallon increase in CNG and LNG gallons delivered, respectively, which was primarily attributable to 2026 new refuse customers sixand nine new transit customers, and two new trucking customers. This increase was partially offset by a 0.6 million decrease in RNG gallons delivered for non-vehicle fuel and a 1.1 million decrease in LNG gallons delivered. Additionally, approximately $0.2 million of the increase in volume related revenues was the result of an increase in the effective price charged per gallon delivered. Our effective price per gallon charged was $0.85$0.69 for the 2016 period,three months ended September 30, 2017, a $0.01$0.16 per gallon increasedecrease from $0.84$0.85 per gallon for the 2015 period. The increase in our effective price charged was primarily due to increased RINs and LCFS Credits sales, which do not result in increased costs. Thethree months ended September 30, 2016. Our effective price per gallon is defined as revenuesrevenue generated from selling CNG, LNG, RNG, and any related RINs and LCFS Credits and providing O&M services to our vehicle fleet customers at stations that

we do not own and for which we receive a per-gallon or fixed fee, all divided by the total GGEs delivered less GGEs delivered by non-consolidated entities, such as entities that are accounted for under the equity method. The decrease in our effective price per gallon between periods was primarily due to lower revenue from sales of RINs and LCFS Credits.

Compressor revenue from CECC, remained relatively comparable between periods, with an increase of $0.6 million.
    
Station construction sales decreased by $1.2 million between periods, principally due to fewer station upgrade projects.

VETC revenues increasedrevenue decreased by $6.7 million between periods as VETC was not in effect in the third quarter of 2015 because all VETC revenues for 2015 were recognized in December 2015 when Congress passed the Consolidated Appropriations Act that included an alternative fuel tax credit.

Station construction sales increased by $2.2 million between periods, principally from the sale of more full station projects than station upgrades in the 2016 period, as full station projects generally have substantially higher price points than station upgrades.

These revenue increases were partially offset by a decrease in Clean Energy Compression's revenue of $7.6 million between periods, which we believe is due to the effectsexpiration of continued lower global oil prices, the strength of the U.S. dollar and slower than expected sales in China.VETC on December 31, 2016.

Cost of sales. Cost of sales decreasedincreased by $4.8$11.4 million to $73.3 million in the three months ended September 30, 2017, from $61.9 million in the three months ended September 30, 2016, from $66.72016. This increase was primarily due to a $13.2 million inventory valuation provision recorded in the three months ended September 30, 2015.2017 which comprised of $7.8 million related to station construction inventory and $5.4 million related to compressor inventory (see "Recent Developments" and Note 2 to the condensed consolidated financial statements included in this report). This decreaseincrease was primarily due to a $6.2 million decrease in compressor costs between periods, as a result of decreased compressor sales andpartially offset by a $0.6 million decrease in gas commodity costs between periods asin station construction cost due to lower construction sales and a result$1.6 million decrease between periods primarily due to reduced costs of a decrease in natural gas prices (discussed below). These decreases were partially offset by a $2.0 million increase in costs related to increased station construction sales between periods.delivered from our facilities.

Our effective cost per gallon decreased by $0.03$0.06 per gallon between periods, to $0.46 per gallon in the three months ended September 30, 2017 from $0.52 per gallon in the three months ended September 30, 2016, from $0.55 per gallon inexcluding the three months ended September 30, 2015.$7.8 million inventory valuation provision discussed above. Our effective cost per gallon is defined as the total costs associated with delivering natural gas, including gas commodity costs, transportation fees, liquefaction charges, and other site operating costs, plus the total cost of providing O&M services at stations that we do not own and for which we receive a per-gallon or fixed fee, including direct technician labor, indirect supervisor and management labor, repair parts and other direct maintenance costs, all divided by the total GGEs delivered less GGEs delivered by non-consolidated entities, such as entities that are accounted for under the equity method investments.method. The decrease in our effective cost per gallon was primarily due to a decreasethe sale of Renewables’ two RNG production facilities in natural gas prices between periods. The decreasethe Asset Sale, resulting in natural gas prices partially offset byno costs to operate these facilities incurred in the increase in gallons delivered resulted in a net decrease of $0.6 million in gas commodity costs between periods.three months ended September 30, 2017.

Gain from change in fair value of derivative warrants. These changes represent the non-cash impact with respect to valuing our outstanding liability-classified warrants based on mark-to-market accounting during the periods.
Selling, general and administrative. Selling, general and administrative expenses decreased by $1.9$1.1 million to $24.8 million in the three months ended September 30, 2017, from $25.9 million in the three months ended September 30, 2016, from $27.8 million in the three months ended September 30, 2015.2016. This decrease was primarily driven by a $0.4 million decreasecontinued cost reduction efforts and reduced administrative costs due to the Asset Sale in employee-related expenses, a $0.8 million decrease in travel and promotional expenses, and a $0.4 million decrease in bad debt expense.2017.
Depreciation and amortization. Depreciation and amortization increaseddecreased by $0.8$0.7 million to $14.1 million in the three months ended September 30, 2017, from $14.8 million in the three months ended September 30, 2016, from $14.0primarily due to the sale of Renewables’ two RNG production facilities in the Asset Sale.
Asset impairments and other charges. During the three months ended September 30, 2017, we recorded employee terminations, asset impairments and other charges of $60.7 million related to our station closures and our natural gas fueling compressor business. For more information, see "Recent Developments" and Note 2 to the condensed consolidated financial statements included in this report.
Interest expense.  Interest expense decreased by $2.1 million to $4.3 million in the three months ended September 30, 2015, due to purchases of property and equipment, primarily for our stations.
Gain (loss)2017, from extinguishment of debt, net. Loss from extinguishment of debt, net was $(0.7)$6.4 million in the three months ended September 30, 2016, primarily consisting of a $(0.9) million loss as a result of repurchasing and retiring $85.0 million in principal amount of our SLG Notes, together with accrued interest thereon. See Note 10 for further information.
Interest expense, net.  Interest expense, net, decreased by $3.9 million to $6.3 million for the three months ended September 30, 2016, from $10.2 million for the three months ended September 30, 2015.2016. This decrease was primarily due to a reduction of outstanding indebtedness under our 5.25% Notes and SLG Notes during the 2016 period. See Note 10 for further information.
Other income (expense), net.  Other income (expense), net, decreased by $(2.7) million to $(0.1) million of expense for the three months ended September 30, 2016, compared to $2.6 million of income for the three months ended September 30, 2015. This decrease was primarily due to a decrease of $1.4 million between periods as result of a litigation settlement that occurred in 2015 which resulted in a gain that was not repeated in 2016, and a decrease of $1.0 million due to $0.9 million in gains from asset disposals that occurred in 2015 compared to $(0.1) million in losses on asset disposals in 2016.periods.
Income tax benefit (expense).  Income tax benefit (expense) decreasedincreased by $(0.6)$0.5 million to $(0.4) million of tax expense for the three months ended September 30, 2016, compared to $0.2 million of tax benefit for the three months ended September 30, 2015. The decreasebetween periods, which was primarily attributable to an increase in taxes on foreign operations between periods.the reduction of goodwill amortization following the Asset Sale.

Loss from noncontrolling interest.  During the three months ended September 30, 2016 and 2017, we recorded a $0.4 million and $0.7 million loss, respectively, for the noncontrolling interest in the net loss of NG Advantage, compared to a $0.1 million loss recorded in the three months ended September 30, 2015.Advantage. The noncontrolling interest in NG Advantage represents a 46.7% minority interest that was held by third parties during the applicable periods.
Gain from extinguishment of debt. In the three months ended September 30, 2016, we recorded a gain of $0.7 million related to the extinguishment of debt. We recorded no comparable gain in the three months ended September 30, 2017.




Nine Months Ended September 30, 20152016 Compared to Nine Months Ended September 30, 20162017     
The table below presents our results of operations as a percentage of total revenue and the narrative that follows provides a detailed discussion of certain line items for the periods presented.
Nine Months Ended September 30, Nine Months Ended September 30,
2015 2016 2016 2017 
Statement of Operations Data: 
  
  
  
 
Revenue: 
  
  
  
 
Product revenues83.9 % 87.5 % 
Service revenues16.1
 12.5
 
Total revenues100.0
 100.0
 
Product revenue87.5 % 83.9 % 
Service revenue12.5
 16.1
 
Total revenue100.0

100.0
 
Operating expenses: 
  
  
  
 
Cost of sales (exclusive of depreciation and amortization shown separately below): 
  
  
  
 
Product cost of sales65.7
 56.8
 56.8
 62.7
 
Service cost of sales8.0
 6.3
 6.3
 8.0
 
Gain from change in fair value of derivative warrants(0.4) 0.0
 
Inventory valuation provision
 5.2
 
Selling, general and administrative32.8
 25.5
 25.5
 28.5
 
Depreciation and amortization15.2
 14.9
 14.9
 17.3
 
Asset impairments and other charges
 24.0
 
Total operating expenses121.3
 103.5
 103.5

145.7

Operating loss(21.3) (3.5) (3.5) (45.7) 
Gain (loss) from extinguishment of debt, net
 8.4
 
Interest expense, net(11.3) (7.7) 
Interest expense(7.9) (5.3) 
Interest income0.2
 0.5
 
Other income (expense), net1.3
 0.0
 0.0
 0.0
 
Loss from equity method investments(0.3) 0.0
 0.0
 0.0
 
Gain (loss) from extinguishment of debt8.4
 1.3
 
Gain from sale of certain assets of subsidiary
 27.7
 
Loss before income taxes(31.6) (2.8) (2.8)
(21.5)
Income tax benefit (expense)(0.5) (0.4) (0.4) 0.9
 
Net loss(32.1) (3.2) (3.2)
(20.6)
Loss from noncontrolling interest0.3
 0.4
 
Loss attributable to noncontrolling interest0.4
 0.7
 
Net loss attributable to Clean Energy Fuels Corp.(31.8)% (2.8)% (2.8)%
(19.9)%
Revenue.    Revenue increaseddecreased by $35.8$48.5 million to $252.3 million in the nine months ended September 30, 2017, from $300.8 million in the nine months ended September 30, 2016, from $265.0 million in the nine months ended September 30, 2015.2016. This increasedecrease was primarily due to increased volumes, increasedthe expiration of VETC in addition to lower volume -related revenue, compressor revenue and station construction sales and increased VETC revenues, partially offset by lower compressor sales.
Volume related revenues increased-related revenue decreased by $15.0$10.8 million between periods, primarily due to reduced revenue received from sales of RINs and LCFS Credits, due in large part to the effects of the Asset Sale and, for the three months ended September 30, 2017, the impact of temporarily stopping sales of LCFS Credits due to restrictions imposed on our LCFS Credit account. See "Key Trends" and Note 3 to the condensed consolidated financial statements included in this report for more information about RINs and LCFS Credits and the Asset Sale, respectively. The decrease in volume -related revenue between periods was partially offset by an increase of 14.720.1 million gallons delivered, which provided approximately $12.7 million of increased revenue. delivered.

This increase in gallons delivered was due to a 23.221.4 million gallon increase in CNG gallons delivered, which was primarily attributable to 2729 new refuse customers, seven16 new transit customers, and threetwo new trucking customers. This increase was partially offset by a 5.40.9 million decrease in LNG gallons delivered as non-vehicle fuel and a 0.4 million decrease in RNG gallons delivered foras non-vehicle fuel and a 3.1 million decrease in LNG gallons delivered. Approximately $2.4 million of the increase in volume related revenues was the result of an increase in the effective price charged per gallon delivered.fuel. Our effective price per gallon charged was $0.86$0.76 for the 2016 period,nine months ended September 30, 2017, a $0.01$0.10 per gallon increasedecrease from $0.85$0.86 per gallon charged for the 2015 period.nine months ended September 30, 2016. The increasedecrease in our effective price per gallon between periods was primarily due to increasedlower revenue from sales of RINs and LCFS creditsCredits.    

Compressor revenue from CECC, decreased by $4.8 million between periods due to lower compressor sales, which do not resultwe believe was primarily due to continued low global demand.
Station construction sales decreased by $13.9 million between periods, principally due to a decrease in increased costs.large, full -station projects and station upgrade projects.

VETC revenues increasedrevenue decreased by $19.6 million between periods as VETC was not in effect in the first nine months of 2015 because all VETC revenues for 2015 were recognized in December 2015 when Congress passed the Consolidated Appropriations Act that included an alternative fuel tax credit.

Station construction sales increased by $20.5 million between periods, principally from the sale of more full station projects than station upgrades in the 2016 period, as full station projections generally have substantially higher price points than station upgrades.

These revenue increases were partially offset by a decrease in Clean Energy Compression's revenue of $19.0 million between periods, which we believe is due to the effectsexpiration of continued low global oil prices, the strength of the U.S. dollar, and slower than expected sales in China.VETC on December 31, 2016.

Cost of sales. Cost of sales decreasedincreased by $5.4$1.7 million to $189.8$191.5 million in the nine months ended September 30, 2016,2017, from $195.2$189.8 million in the nine months ended September 30, 2015. The decrease2016. This increase was primarily due to a $18.7 million decrease in compressor costs between periods, due to decreased compressor sales and a $4.1 million decrease in gas commodity costs between periods as a result of a decrease in natural gas prices (discussed below). These decreases were partially offset by a $17.3$4.6 million increase in costs related to station constructioncost of sales primarily due to increased natural gas volumes delivered between periods and a $13.2 million inventory valuation provision charge recorded in the nine months ended September 30, 2017 which comprised of $7.8 million related to station construction inventory and $5.4 million related to compressor inventory (see "Recent Developments" and Note 2 to the condensed consolidated financial statements included in this report). This increase was offset by a $10.0 million decrease between periods in station construction costs due to lower station construction sales and a $6.1 million decrease between periods.periods in compressor costs due to lower compressor sales.

Our effective cost per gallon decreased by $0.06$0.02 per gallon between periods, to $0.49 per gallon in the nine months ended September 30, 2017 from $0.51 per gallon in the nine months ended September 30, 2016, from $0.57 per gallon in excluding the nine months ended September 30, 2015.$7.8 million inventory valuation provision discussed above. The decrease in our effective cost per gallon was primarily due to a decreasethe sale of Renewables’ two RNG production facilities in natural gas prices between periods. The decreasethe Asset Sale, resulting in natural gas prices partially offset byno costs to operate these facilities incurred in the increase in gallons delivered resulted in a net decreaselast six months of $4.1 million in gas commodity costs between periods.the nine months ended September 30, 2017.

Gain from change in fair value of derivative warrants. These changes represent the non-cash impact with respect to valuing our outstanding liability-classified warrants based on mark-to-market accounting during the periods.
Selling, general and administrative. Selling, general and administrative expenses decreased by $10.2$4.8 million to $76.8$71.9 million in the nine months ended September 30, 2017, from $76.7 million in the nine months ended September 30, 2016. This decrease was primarily driven by continued cost reduction efforts and reduced administrative costs due to the Asset Sale in 2017.
Depreciation and amortization. Depreciation and amortization decreased by $0.9 million to $43.8 million in the nine months ended September 30, 2017, from $44.7 million in the nine months ended September 30, 2016, from $87.0primarily due to the sale of Renewables’ two RNG production facilities in the Asset Sale.
Asset impairments and other charges.  During the nine months ended September 30, 2017, we recorded employee terminations, asset impairments and other charges of $60.7 million related to our station closures and our natural gas fueling compressor business. For more information, see "Recent Developments" and Note 2 to the condensed consolidated financial statements included in this report.
Interest expense.  Interest expense decreased by $10.3 million to $13.5 million in the nine months ended September 30, 2015. This decrease was primarily driven by a $5.6 million decrease in employee-related expenses, a $3.2 million decrease in travel and promotional expenses due to company-wide cost cutting measures, and a $1.0 million decrease in bad debt expense.
Depreciation and amortization. Depreciation and amortization increased by $4.4 million to $44.72017, from $23.8 million in the nine months ended September 30, 2016, from $40.3 million in the nine months ended September 30, 2015 due to purchases made in prior periods of property and equipment, primarily for our stations.
Gain (loss) from extinguishment of debt, net. Gain from extinguishment of debt, net was $25.4 million in the nine months ended September 30, 2016 as a result of repurchasing and retiring $215.4 million in principal amount of our 5.25% Notes and SLG Notes, together with $2.8 million accrued and unpaid interest thereon, for an aggregate purchase price of $125.6 million in cash and 20.3 million shares of our common stock. See Note 10 for further information.
Interest expense, net.  Interest expense, net, decreased by $6.7 million to $23.3 million for the nine months ended September 30, 2016, from $30.0 million for the nine months ended September 30, 2015.2016. This decrease was primarily due to a reduction of outstanding indebtedness under our 5.25% Notes and SLG Notes in an aggregate principal amount of $215.4 million during the 2016 period. See Note 10 for further information.between periods.
Other incomeIncome tax benefit (expense), net.  Other income.  Income tax benefit (expense), net decreased increased by $(3.5)$3.4 million to $(0.01)$2.2 million of expense fortax benefit in the nine months ended September 30, 2016,2017, compared to $3.5$(1.2) million of income fortax expense in the nine months ended September 30, 2015. This decrease2016. The increase in income tax benefit was primarily due to a $(0.8) million increase in the loss from foreign currency transactions not in our subsidiaries’ functional currency, a decrease of $1.4 million between periods as result of a litigation settlement that occurred in 2015 which resulted in a gain that was not repeated in 2016 and a $1.3 million decrease due to $0.9 million in gain from assets disposals that occurred in 2015 compared to ($0.4) million in losses from disposal of assets in 2016.
Incomedeferred tax expense.  Income tax expense decreased by $0.2 million to $1.2 million for the nine months ended September 30, 2016, compared to $1.4 million for the nine months ended September 30, 2015. The decrease was primarilybenefit attributable to a decrease in taxes on foreign operations between periods.the reduction of goodwill amortization following the Asset Sale.
Loss from noncontrolling interest.  During the nine months ended September 30, 2016, and 2017, we recorded a $1.3 million and $1.8 million loss, respectively, for the noncontrolling interest in the net loss of NG Advantage, compared to a $0.8 million loss recorded in the nine months ended September 30, 2015.Advantage. The noncontrolling interest in NG Advantage represents a 46.7% minority interest which that was held by third parties during the applicable periods.
Gain from extinguishment of debt. Gain from extinguishment of debt decreased by $22.2 million to $3.2 million in the nine months ended September 30, 2017, from $25.4 million in the nine months ended September 30, 2016. This decrease was primarily due to our repurchase of a lower principal amount of debt at higher prices in the nine months ended September 30, 2017 compared to the comparable 2016 period.
Gain from sale of certain assets of subsidiary. In the nine months ended September 30, 2017, we recorded a gain of $69.9 million related to the Asset Sale. We recorded no comparable gain in the nine months ended September 30, 2016.

Seasonality and Inflation
To some extent, we experience seasonality in our results of operations. Natural gas vehicle fuel amounts consumed by some of our customers tend to be higher in summer months when buses and other fleet vehicles use more fuel to power their air conditioning systems. Natural gas commodity prices tend to be higher in the fall and winter months due to increased overall demand for natural gas for heating during these periods.
Since our inception,Historically, inflation has not significantly affected our operating results; however, costs for construction, repairs, maintenance, electricity and insurance are all subject to inflationary pressures, which could affect our ability to maintain our stations adequately, build new stations, expand our existing facilities or pursue additional RNG production projects orfacilities, and could materially increase our operating costs.
Liquidity and Capital Resources
We require cash to fund our capital expenditures, operating expenses and working capital requirements, including outlays for the design and construction of new fueling stations and additions or other modifications to existing fuel stations, debt repayments and repurchases, maintenance of LNG production facilities, purchases of new CNG tanker trailers, investment in RNG production, manufacturing natural gas fueling compressors and related equipment, mergers and acquisitions (if any), financing natural gas vehicles for our customers and general corporate purposes, including geographic expansion (domestically and internationally), pursuing new customer markets, supporting our sales and marketing activities, supporting legislative and regulatory initiatives and for working capital. Historically, our principal sources of liquidity have consisted of cash on hand, cash provided by our operations, including, if available, VETC and other credits, and cash provided by financing activities and sales of assets.
Liquidity
Liquidity is the ability to meet present and future financial obligations through operating cash flows, the sale or maturity of investments or the acquisition of additional funds through capital management. Our financial position and liquidity are, and will continue to be, influenced by a variety of factors, including the level of our outstanding indebtedness and the principal and interest we are obligated to pay on our indebtedness, our capital expenditure requirements and any merger, divestiture or acquisition activity, as well as our ability to generate cash flows from our operations. We expect cash provided by our operating activities to fluctuate as a result of a number of factors, including our operating results, and the timing and amount of our billing, collections and liability payments, completion of our station construction projects and receipt of government grants and tax and other fuel credits.

Cash provided byFlows

Cash used in operating activities was $44.2$(4.9) million in the nine months ended September 30, 2016,2017, compared to $1.0$44.2 million used inprovided by operating activities in the prior comparable 2016 period. The increase$49.1 million decrease in cash provided by operating activities was primarily due to payment of transaction fees related to the result of $12.0 millionAsset Sale and a reduction in VETC cash collected as well as improved operating results of approximately $40.7 million, exclusive of non-cash expenses and gains. Partially offsetting a portion of this improvement were net changes in working capital of $7.4 million, principallydue to the decreased revenue from increased receivablessales of RINs and LCFS Credits, inas discussed under "Key Trends" and "Results of Operations" above and the nine months ended September 30, 2016 compared to the same period in 2015 as a resultexpiration of increased sales of those credits in the 2016 period.VETC.

Cash provided by investing activities was $9.5$57.2 million in the nine months ended September 30, 2016,2017, compared to $32.6$9.5 million used inprovided by investing activities in the prior comparable 2016 period. The $47.7 million increase in cash provided by investing activities was primarily attributable to decreased capital expenditures$154.5 million in cash received, net of $23.6cash transferred, in connection with the Asset Sale (see "Recent Developments" and Note 3 to the condensed consolidated financial statements included in this report for more information) and an $8.4 million between periods, whichpayment made to NG Advantage related to an arrangement with one of its customers for the purchase, sale and transportation of CNG over a five-year period (see "Recent Developments" for more information). The increase was largely due to decreased constructionpartially offset by incremental purchases of Company-owned stations. Additionally, cash provided by our short-term investments, that matured, net of maturities, of $103.4 million in the nine months ended September 30, 2017, compared to the comparable 2016 period and a $10.9 million increase in purchases increasedof equipment, primarily related to deposits by $17.9 million between periodsNG Advantage for CNG trailers and cash provided as a return of capital from our equity method investment increased by $3.0 million between periods.equipment.
    
Cash used in financing activities in the nine months ended September 30, 20162017 was $57.2$43.9 million, compared to $4.3$57.2 million used in financing activities in the prior comparable 2016 period. The increase$13.3 million decrease in cash used in financing activities was primarily due to a $122.8$79.3 million increase in scheduled debt payments and repayments of long term debt prior to maturity. Partially offsetting this increasedecrease in cash used in financing activitiesdebt repurchases, net of borrowings. This decrease was partially offset by a $68.3$57.4 million increasedecrease in cash provided by financing activities as a result of our sales of common stock through the ATM program (as definedProgram, net of fees, which was terminated on May 31, 2017, and discussed below).an $8.6 million payment to holders of Renewables Option Awards associated with the Asset Sale in the nine months ended September 30, 2017.

Capital Expenditures and Other Uses of Cash

We require cash to fund our capital expenditures, operating expenses and working capital requirements, including costs associated with fuel sales, outlays for the design and construction of new fueling stations, additions or other modifications to existing fueling stations, debt repayments and repurchases, purchases of CNG tanker trailers and natural gas heavy-duty trucks, maintenance of LNG production facilities, manufacturing natural gas fueling compressors and other equipment , mergers and acquisitions (if any), financing natural gas vehicles for our customers and general corporate purposes, including geographic expansion (domestically and internationally), pursuing new customer markets and supporting our sales and marketing activities, including supporting legislative and regulatory initiatives.


Our business plan callscalled for approximately $25.5$29.0 million in capital expenditures for all of 2016,2017, although as of September 30, 2017 we estimate actual capital expenditures will approximate $23.0 million for 2017. Our capital expenditures primarily relatedrelate to the construction of CNG and LNG fueling stations, andadditional investments in fueling stations to add CNG fueling, the purchase of natural gas heavy-duty trucks, the purchase of additional CNG trailers and equipment by NG Advantage to support its transport and sale of CNG to a lesser extent,industrial and institutional energy users, and LNG plant maintenance costs and RNG plant construction and maintenance costs.

In addition, NG Advantage planned to spend $24.0 million to purchase other equipment to support a customer arrangement established in June 2017. As of September 30, 2017, NG Advantage has spent $13.6 million related to this customer arrangement.

We had total indebtedness of approximately $355.5$255.8 million in principal amount as of September 30, 2016,2017, of which approximately $1.0$1.2 million, $4.8$139.5 million, $234.5 million, $54.7$53.7 million, $53.8 million, $3.3 million and $6.7$4.3 million is expected to become due in 2016, 2017, 2018, 2019, 2020, 2021 and thereafter, respectively. Additionally, we expect our total interest payment obligations relating to our indebtedness to be approximately $29.5$20.0 million in 2016, $21.62017, $14.4 million of which hashad been paid when due as of September 30, 2016. Although we do not have a specific plan regarding the repurchase, redemption or restructuring of our outstanding indebtedness, we2017. We generally intend to make payments under our various debt instruments when due and pursue opportunities for earlier repayment and/or refinancing if and when these opportunities arise. With respect to our 5.25% Notes, our board of directors has authorized and approved the use of up to $50.0 million to opportunistically purchase outstanding 5.25% Notes in the open market and at the date of this report we have used an aggregate $24.9 million for such purchases.

We may also elect to invest additional amounts in companies, assets or joint ventures in the natural gas fueling infrastructure, vehicle or services industries including RNG production, or use capital for other activities or pursuits.pursuits, in addition to those described above.

Sources of Cash
Historically, our principal sources of liquidity have consisted of cash on hand, cash provided by our operations, including, if available, grants, VETC and other credits, and cash provided by financing activities and sales of assets. AtAs of September 30, 2016,2017, we had total cash and cash equivalents and short-term investments of $118.9$196.8 million, compared to $146.7$109.8 million at December 31, 2015.2016.     
OnWe expect cash provided by our operating activities to fluctuate depending on our operating results, which can be affected by the amount and timing of station construction sales, sales of RINs and LCFS Credits and recognition of any other government credits and, compressor and other equipment sales; fluctuations in commodity costs and natural gas prices and sale activity; and the amount and timing of our billing, collections and liability payments, among other factors. See "Risk Factors" in Part II, Item 1A of this report for more information.

From the commencement of the ATM Program in November 11, 2015 until our termination of the Sales Agreement on May 31, 2017, we entered into an equity distribution agreement with Citigroup asreceived aggregate net proceeds of $117.9 million from sales agent and/or principal, pursuant to which we may issue and sell, from time to time, through or to Citigroup, shares of our common stock having an aggregate offering price of up to $75.0 million in an “at-the-market” offering program (the “ATM Program”). On September 9, 2016, we entered into an amended and restated equity distribution agreement with Citigroup, which amends, restates, and replacesunder the original equity distribution agreement in its entirety, for the primary purpose of increasing from $75.0 million to $110.0 million, the aggregate offering price of shares of common stock available for issuance and sale in the ATM Program.Sales Agreement.

ThisThe following table summarizes the activity under the ATM Program for the following periods:periods presented:

  Three Months Ended September 30, Nine Months Ended September 30, Through November 3, 
(in millions) 2016 2016 2016 
Gross proceeds $16.1
 $69.1
 $83.1
 
Fees and issuance costs 0.4
 1.7
 2.4
 
Net proceeds $15.7
 $67.4
 $80.7
 
Shares issued 3.8
 21.3
 24.5
 

As of the date of this report, shares of common stock having an approximate value of $26.9 million remain available for sale through the ATM Program. We continue to use any net proceeds from the ATM Program for general corporate purposes, including retiring a portion of our outstanding indebtedness.
  Nine Months Ended September 30, Nine Months Ended September 30, Inception through May 31, 
(in millions) 2016 2017 2017 
Gross proceeds $69.1
 $10.8
 $121.3
 
Fees and issuance costs 1.7
 0.3
 3.4
 
Net proceeds $67.4
 $10.5
 $117.9
 
Shares issued 21.3
 3.8
 36.4
 
    
On February 29, 2016, we entered into the Credit Facilitya loan and security agreement with, Plains,and issued a related promissory note to PlainsCapital Bank ("Plains"), pursuant to which Plains agreed to lend us up to $50.0 million on a revolving basis for a term of one year.year (the "Credit Facility"). Simultaneously, we drew down $50.0 million under the Credit Facility, which we repaid in full on August 31, 2016. As a result, no amounts were outstanding under the Credit Facility as of September 30, 2016. On October 31, 2016, the Credit Facility's maturity date was extended from February 28, 2017 to September 30, 2018. On December 22, 2016, we drew $23.5 million under the Credit Facility, which we repaid in full on March 31, 2017.

See Note 1013 to the condensed consolidated financial statements included in this report for additionalmore information about our outstanding debt.

On March 31, 2017, Renewables completed the Asset Sale. The net proceeds to us from the Asset Sale were approximately $142.2 million. See “Recent Developments” and Note 3 to the condensed consolidated financial statements included in this report for more information.

We believe that our current cash and cash equivalents and short-term investments and cash provided by our operating and financing activities will satisfy our routine business requirements for at least the next 12 months;months following the date of this report; however, we willwould need to raise additional capital to fund any planned or unanticipated capital expenditures, investments or debt repayments that we cannot fund through available cash, or cash provided by our operations or that we cannot fund through other sources, such as with our common stock.

The timing and necessity of any future capital raise would depend on various factors, including our rate and volume of natural gas sales and other volume-related activity, new station construction, debt repayments (either prior to or at maturity), and any potential merger, acquisition, investment or acquisitiondivestiture activity, andas well as the other factors described under “—Liquidity” above.that affect our revenue levels.

We may seek to raise additional capital through one or more sources, including, among others, selling assets, obtaining new or restructuring existing debt, obtaining equity capital, (including through the ATM Program or other equity offerings), or any combination of these or other availablepotential sources of capital. We may not be able to raise capital when needed, on terms that are favorable to us or our stockholders or at all. Any inability to raise necessary capital may impair our ability to build new stations, develop natural gas fueling infrastructure, maintain our stations, invest in strategic transactions or acquisitions or repay our outstanding indebtedness and may reduce our ability to build our business and generate sustained or increased revenues.revenue.


Off-Balance Sheet Arrangements
AtAs of September 30, 2016,2017, we had the following off-balance sheet arrangements that had, or are reasonably likely to have, a material effect on our financial condition, changes in financial condition, revenues or expenses, results of operations, liquidity, capital expenditures or capital resources:
Outstanding surety bonds for construction contracts and general corporate purposes totaling $59.1 million ;$28.9 million;
Two long-term take-or-pay contracts for the purchase of natural gas;
An outstanding commitment to purchase 136 natural gas heavy -duty trucks valued at $8.8 million; and
Operating leases where we are the lessee.
We provide surety bonds primarily for construction contracts in the ordinary course of our business, as a form of guarantee. No liability has been recorded in connection with our surety bonds as we do not believe, based on historical experience and information currently available, that it is probable that any amounts will be required to be paid under these arrangements for which we will not be reimbursed.
We have two long-term take-or-pay contracts that require us to purchase minimum volumes of natural gas. These contractsgas at index based prices which expire in March 2020 and December 2020.2020, respectively.
We have entered into an arrangement to purchase 136 used natural gas heavy-duty trucks valued at $8.8 million by December 31, 2017, with the intention of selling the trucks to our customers.
We have entered into operating lease arrangements for certain equipment and for our office and field operating locations in the ordinary course of our business. The terms of our leases expire at various dates through 2021.2038. Additionally, in November 2006, we entered into a ground lease for 36 acres in California on which we built our California LNG liquefaction plant. The lease is for an initial term of 30 years and requires payments of $0.2 million per year, plus up to $0.1 million per year for each 30 million gallons of production capacity utilized, subject to future adjustment based on consumer price index changes. We must also pay a royalty to the landlord for each gallon of LNG produced at the facility, as well as a fee for certain other services that the landlord provides.
Item 3.—Quantitative and Qualitative Disclosures about Market Risk
In the ordinary course of our business, we are exposed to various market risks, including commodity price risks and risks related to foreign currency exchange rates.
Commodity Price Risk
We are subject to market risk with respect to our sales of natural gas, which have historically been subject to volatile market conditions. Our exposure to market risk is heightened when we have a fixed-price sales contract with a customer that is not covered by a futures contract, or when we are otherwise unable to pass through natural gas price increases to customers. Natural gas prices and availability are affected by many factors, including, among others, drilling activity, supply, weather conditions, overall economic conditions and foreign and domestic government regulations.
Natural gas costs represented $75.7$72.8 million of our cost of sales in 20152016 and $52.5$62.9 million of our cost of sales for the nine months ended September 30, 2016.2017.
To reduce price risk caused by market fluctuations in natural gas, we may enter into exchange traded natural gas futures contracts. These arrangements expose us to the risk of financial loss in situations where the other party to the contract defaults on the contract or there is a change in the expected differential between the underlying price in the contract and the actual price of natural gas we pay at the delivery point. We did not have any natural gas futures contracts outstanding at September 30, 2016.2017.
Foreign Currency Exchange Rate Risk
Because we have foreign operations, we are exposed to foreign currency exchange gains and losses. Since the functional currency of our foreign subsidiaries is in their local currency, the currency effects of translating the financial statements of those foreign subsidiaries, which operate in local currency environments, are included in the accumulated other comprehensive income (loss)loss component of consolidated equity in our condensed consolidated financial statements and do not impact earnings. However, foreignForeign currency transaction gains and losses not in our subsidiaries’ functional currency, however, do impact earnings and resulted in approximately $0.2 million of gainslosses in the nine months ended September 30, 2016. During the nine months ended September 30, 2016,2017. In this period, our primary exposure to foreign currency exchange rates related to our Canadian operations that had certain outstanding accounts receivable and accounts payable denominated in the U.S. dollar, which were not hedged.


We have prepared a sensitivity analysis to estimate our exposure to market risk with respect to our monetary transactions denominated in a foreign currency. If the exchange rates on these assets and liabilities were to fluctuate by 10% from the rates as of September 30, 2016,2017, we would expect a corresponding fluctuation in the value of the assets and liabilities of approximately $1.6$1.0 million.

Item 4.—Controls and Procedures
Evaluation of Disclosure Controls and Procedures
We maintain disclosure controls and procedures that are designed to ensure that information required to be disclosed in the reports that we file or submit under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), is recorded, processed, summarized and reported within the time periods specified in the rules and forms of the Securities and Exchange Commission, and that such information is accumulated and communicated to our management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow timely decisions regarding required disclosure. In designing the disclosure controls and procedures, management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving the desired control objectives. In addition, the design of our disclosure controls and procedures must reflect the fact that there are resource constraints and that management is required to apply its judgment in evaluating the benefits of possible controls and procedures relative to their costs.
Our management carried out an evaluation, under the supervision of and with the participation of our Chief Executive Officer and Chief Financial Officer (our principal executive and principal financial officers, respectively), of the effectiveness of our disclosure controls and procedures. Based on this evaluation, our Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were effective as of the end of the period covered by this report.
Changes in Internal Control over Financial Reporting
We regularly review and evaluate our internal control over financial reporting and make changes to our processes and systems to improve controls and increase efficiency, while ensuring that we maintain an effective internal control environment. Changes may include such activities as implementing new, more efficient systems, consolidating activities, and migrating processes.
There were no changes in our internal control over financial reporting that occurred during our most recently completed fiscal quarter that have materially affected, or are reasonably likely to materially affect, our internal control over financial reporting.

    


PART II.—OTHER INFORMATION
Item 1. —Legal Proceedings
We are or may become party, and our property may become subject, to various legal actions that have arisenarise in the ordinary course of our business. During the course of our operations, weWe are also subject to audit by tax and other authorities for varying periods in various federal, state, local and foreign tax jurisdictions. Disputesjurisdictions, and disputes have arisen, and may continue to arise, during the course of such audits as to facts and matters of law.these audits. It is impossible to determine the ultimate liabilities that we may incur resulting from any of these lawsuits, claims, and proceedings, audits, commitments, contingencies and related matters or the timing of these liabilities, if any. If these matters were to ultimately be resolved unfavorably, an outcome not currently anticipated, it is possible that such an outcome could have a material adverse effect upon our consolidated financial position, results of operations or liquidity. However,We do not, however, anticipate such an outcome and we believe that the ultimate resolution of suchthese matters will not have a material adverse effect on our consolidated financial position, results of operations or liquidity.

Item 1A.—Risk Factors
An investment in our Company involves a high degree of risk of loss. You should carefully consider the risk factors discussed below and all of the other information included in this report and our 20152016 Form 10-K before you make any investment decision regarding our securities. We believe the risks and uncertainties described below are the most significant we face. The occurrence of any of the followingthese risks could harm our business, financial condition, results of operations, prospects and reputation and could cause the trading price of our common stock to decline. Additional risks and uncertainties not known to us or that we deem immaterial may also impair our business.
We have a history of losses and may incur additional losses in the future.
For the years ended December 31, 2013,In 2014, and 2015 and the nine months ended September 30, 2016, we incurred pre-tax losses of $63.2 million, $89.9$89.8 million, $133.8 million, and $8.4$12.4 million respectively. During these periods our losses were substantially decreased by approximately $45.4 million, $28.4 million, $31.0 million and $19.6 million of revenue respectively, from a federal alternative fuels tax credit ("VETC")., totaling $28.4 million, $31.0 million, and $26.6 million in 2014, 2015 and 2016, respectively. On December 31, 2016, however, VETC expired, and it may not be available for any period after that date. We may continue to incur losses, orthe amount of our losses may increase, and we may never achieve or maintainsustain profitability, any of which would adversely affect our business, prospects and financial condition and may cause the price of our common stock to fall. In addition, to try to achieve or sustain profitability, we may take actions that result in material costs or material asset impairments. For instance, in the three months ended September 30, 2017, we recorded significant charges in connection with our closure of certain fueling stations, our natural gas fueling compressor business, our determination of an impairment of assets as a result of the foregoing, and certain other actions. Any such actions could have material adverse consequences, including material negative effects on our financial condition, our results of operations or the trading price of our common stock.
Our success is dependent upon the willingness of fleets and other consumers to adopt natural gas as a vehicle fuel, which may not occur in a timely manner, at expected levels or at all.

Our success is highly dependent upon the adoption by fleets and other consumers of natural gas as a vehicle fuel. To date, adoption and deployment of natural gas vehicles have been slower and more limited than we anticipated. If the market for natural gas as a vehicle fuel continues to develop at this rate and level, or if a market develops but we are not able to capture a significant share of the market or the market subsequently declines, our business, prospects, financial condition and operating results would be harmed.

The market for natural gas as a vehicle fuel is a relatively new and developing market characterized by competition, evolving government regulation and industry standards and changing consumer demands and behaviors.
Factors that may influence the adoption of natural gas as a vehicle fuel include, among others:
Increases, decreases or volatility in the supply, demand, use and prices of crude oil, gasoline, diesel, natural gas and other vehicle fuels, such as electricity, hydrogen, renewable diesel, biodiesel and ethanol;

Perceptions about the need for alternative vehicle fuels generally;

Perceptions about the benefits of conventional and renewable natural gas relative to gasoline and diesel and other alternative vehicle fuels, including with respect to factors such as cost savings, supply and environmental and safety benefits;

The availability or perceived availability of, consumer acceptance of or preference for, or favor by lawmakers, regulators, other policymakers, environmental organizations or other powerful groups for non-natural gas fuels and

vehicles, including long-standing support for gasoline and diesel-powered vehicles and growing favor for electric and/or hydrogen-powered vehicles;

Advances or improvements in non-natural gas vehicle fuels or engines powered by these fuels, including improvements in the efficiency, fuel economy or greenhouse gas emissions of these engines;

Natural gas vehicle cost, fuel usage, availability (including for heavy, medium and light-duty applications), quality, safety, design and performance, all relative to comparable vehicles powered by other fuels;

The existence of environmental, tax or other government regulations, programs or incentives that promote natural gas or other alternatives as a vehicle fuel, including, among others, tax credits, grants, renewable fuel standards and low carbon fuel standards;

Changes to emissions requirements applicable to vehicles powered by gasoline, diesel, natural gas or other vehicle fuels, as well as the impact of emissions and other environmental regulations and pressures on crude oil and natural gas drilling, production, importing and transportation methods and fueling stations for these fuels;

The environmental consciousness of fleets and consumers;

Access to natural gas fueling stations and the convenience and cost to fuel and service natural gas vehicles, all relative to comparable vehicles powered by other fuels; and

The other risks discussed in these risk factors.

If there are advances or improvements in non-natural gas vehicle fuels or engines powered by these fuels, demand for natural gas vehicles may decline.
Use of electric heavy-duty trucks, buses and refuse trucks, or the perception that such vehicles may soon be widely available and provide satisfactory performance at an acceptable cost, may reduce demand for natural gas vehicles in these applications, which are key customer markets for our business. In addition, renewable diesel, hydrogen and other alternative fuels in development may prove to be, or may be perceived to be, cleaner, more cost-effective, more readily available or otherwise more beneficial alternatives to gasoline and diesel than renewable natural gas ("RNG"), compressed natural gas ("CNG") or liquefied natural gas ("LNG") (RNG can be delivered in the form of CNG or LNG). Further, technological advances in the production, delivery and use of gasoline, diesel or other alternative vehicle fuels, or the failure of natural gas vehicle fuel technology to advance at an equal pace, could slow or limit adoption of natural gas vehicles. For example, advances in gasoline and diesel engine technology, including efficiency improvements and further development of hybrid engines, may offer a cleaner, more cost-effective option and reduce the likelihood that fleet customers convert their vehicles to natural gas. Additionally, technological advances related to ethanol or biodiesel, which are used as an additive to or substitute for gasoline and diesel fuel, may influence the market's perception of the need to diversify fuels and, as a result, negatively affect the growth of the natural gas vehicle fuel market.

Increases, decreases and general volatility in oil, gasoline, diesel and natural gas prices could adversely affect our business.
Prices for crude oil, the commodity used to make gasoline and diesel, today's most prevalent vehicle fuels, have been low in recent years, due in part to over-production and increased supply without a corresponding increase in demand. Market adoption of natural gas as a vehicle fuel could be slowed or limited if the over-supply and resulting low prices of crude oil, gasoline and diesel continue or worsen, or if the price of natural gas increases without equal and corresponding increases in the prices of crude oil, gasoline and diesel. Any of these circumstances could decrease the market's perception of a need for alternative vehicle fuels generally, which could cause the success or perceived success of our industry and our business to materially suffer. In addition, if prices of gasoline and diesel decrease or prices of natural gas increase, we may not be able to offer our customers an attractive pricing advantage for CNG and LNG and maintain an acceptable margin on our sales. Any such failure could result in an inability to attract new customers or a loss of demand from existing customers, or could directly and negatively impact our results of operations if we are forced to reduce the prices at which we sell natural gas to try to avoid such an effect on our customer base.

Pricing conditions also exacerbate the cost differential between natural gas vehicles and gasoline or diesel- powered vehicles, which may lead operators to delay or refrain from purchasing or converting to natural gas vehicles. Generally, natural gas vehicles cost more initially than gasoline or diesel-powered vehicles, as the components needed for a vehicle to use natural gas add to the vehicle’s base cost. Operators then seek to recover the additional cost of acquiring or converting to natural gas vehicles over time, through the lower cost of fueling natural gas vehicles. Operators may, however, perceive an inability to timely recover th

ese additional initial costs if CNG and LNG fuel are not available at prices sufficiently lower than gasoline and diesel. Such an outcome would decrease our potential customer base and harm our business prospects.

Additionally, the price of natural gas, as well as the prices of crude oil, gasoline and diesel, has been volatile in recent years, and this volatility may continue. Fluctuations in natural gas prices affect the cost to us of the natural gas commodity. High natural gas prices adversely impact our operating margins when we cannot pass the increased costs through to our customers. Conversely, lower natural gas prices reduce our revenue when the commodity cost is passed through to our customers. As a result, these fluctuations in natural gas prices can have a significant and adverse impact on our operating results.

Factors that can cause fluctuations in gasoline, diesel and natural gas prices include, among others, changes in supply and availability of crude oil and natural gas, government regulations and political conditions, inventory levels, consumer demand, price and availability of alternative fuels, weather conditions, negative publicity about crude oil or natural gas drilling, production or importing techniques and methods, economic conditions and the price of foreign imports.

With respect to natural gas supply, there have been efforts in recent years to impose new regulatory requirements on the production of natural gas by hydraulic fracturing of shale gas reservoirs and other means and on transporting, dispensing and using natural gas. Hydraulic fracturing and horizontal drilling techniques have resulted in a substantial increase in the proven natural gas reserves in the United States. Any changes in regulations that make it more expensive or unprofitable or otherwise impose additional burdens to produce natural gas through these techniques or others, as well as any changes to the regulations relating to transporting, dispensing or using natural gas, could lead to further volatility in, and generally increased, natural gas prices. If all or some combination of these factors cause continued or further volatility in natural gas, gasoline and diesel prices, our business and our industry could be materially harmed.

Vehicle and engine manufacturers produce very few natural gas vehicles and engines in our key markets, which limits our customer base and our sales of CNG, LNG and RNG.
Original equipment manufacturers produce a relatively small number of natural gas engines and vehicles in the U.S. and Canadian markets. Further, these manufacturers may not decide to expand, or they may decide to discontinue or curtail, their natural gas engine or vehicle product lines. The limited production of natural gas engines and vehicles increases the cost to purchase these vehicles and limits their availability, which restricts their large-scale introduction and adoption. As a result of these and other factors, the limited supply of natural gas vehicles could reduce our potential customer base and natural gas fuel sales, which would harm our business and prospects.
Our business is influenced by environmental, tax and other government regulations, programs and incentives that promote natural gas or other alternatives as a vehicle fuel, and their adoption, modification or repeal could negatively impact our business.
Our business is influenced by federal, state and local government tax credits, rebates, grants and similar programs and incentives that promote the use of CNG, LNG and RNG as a vehicle fuel, including the VETC, which expired on December 31, 2016 and may not be available for any period after that date, and various government programs that make available grant funds for the purchase and construction of natural gas vehicles and fueling stations. Additionally, our business is influenced by laws, rules and regulations that require reductions in carbon emissions and/or the use of renewable fuels, such as the California and Oregon Low Carbon Fuel Standards and the federal Renewable Fuel Standard Phase 2, under which we generate credits ("LCFS Credits" and "RIN Credits" or "RINs," respectively) by selling CNG, LNG and RNG as a vehicle fuel.

These programs and regulations, which have the effect of encouraging the use of CNG, LNG or RNG as a vehicle fuel, could expire or be repealed or amended for a variety of reasons. For example, parties with an interest in gasoline and diesel or other alternative vehicle fuels, including lawmakers, regulators, other policymakers, environmental organizations or other powerful groups, many of which have substantially greater resources and influence than we have, invest significant time and money in efforts to delay, repeal or otherwise negatively influence regulations and programs that promote natural gas as a vehicle fuel. Further, changes in federal, state or local political, social or economic conditions could result in the modification or repeal of these programs or regulations. Any failure to adopt, delay in implementing, expiration, repeal or modification of these programs and regulations, or the adoption of any such programs and regulations that encourage the use of other alternative fuels or alternative vehicles over natural gas, could harm our operating results and financial condition.
We face increasing competition from a variety of businesses, many of which have far greater resources, experience, customer bases and brand awareness than we have, and we may not be able to compete effectively with these businesses.
The market for vehicle fuels is highly competitive. The biggest competition for CNG and LNG use as a vehicle fuel is gasoline and diesel, as the vast majority of vehicles in our markets are powered by these fuels. We also compete with suppliers of

other alternative vehicle fuels, including renewable diesel, biodiesel and ethanol, as well as producers and fuelers of alternative vehicles, including hybrid, electric and hydrogen-powered vehicles. Additionally, our stations compete directly with other natural gas fueling stations and indirectly with electric vehicle charging stations and fueling stations for other alternative vehicle fuels. Further, for certain of our key customer markets, such as airports, we indirectly compete with companies such as Uber and Lyft that provide transportation methods serving as alternatives to taxi cabs. We also face high levels of competition with respect to our other business activities, including our current manufacture and sale of natural gas fueling compressors and other equipment, our procurement and sale of RNG and our sale of CNG and LNG to industrial and institutional energy users or for other non-vehicle purposes.

A significant number of established businesses, including oil and gas companies, alternative vehicle and alternative fuel companies, refuse collectors, utilities and their affiliates, industrial gas companies, truck stop and fuel station owners, fuel providers and other organizations have entered or may enter the market for natural gas and other alternatives for use as a vehicle fuel. Many of these competitors have longer operating histories, more experience, larger customer bases, greater brand recognition and market penetration and substantially greater financial, marketing, research and other resources than we have. As a result, they may be able to respond more quickly to changes in customer preferences, legal requirements or other industry trends, devote greater resources to the development, promotion and sale of their products, adopt more aggressive pricing policies, dedicate more effort to infrastructure and systems development in support of their business or product development activities or exert more influence on the regulatory landscape that impacts the vehicle fuels market. Additionally, utilities and their affiliates typically have additional and unique competitive advantages, including a lower cost of capital, substantial and predictable cash flows, long-standing customer relationships, greater brand awareness and large and well-trained sales and marketing organizations. We may not be able to compete effectively against any of these organizations.

We expect competition to increase in the alternative vehicle fuels market generally and, if the demand for natural gas vehicle fuel increases, in the market for natural gas vehicle fuel. Any such increased competition may reduce our customer base and revenue and may lead to pricing pressure, reduced operating margins and fewer expansion opportunities.
Servicing our debt requires a significant amount of cash, and we may not have sufficient cash flow from our business to pay our debt.
AtAs of September 30, 2016,2017, our total indebtedness was approximately $355.5$255.8 million in principal amount, which includes amounts owed under the 7.5% Notes, 5.25% Notes and Canton Bonds, each of which is defined and discussed in Note 10 to our condensed consolidated financial statements included in this report.amount. As of September 30, 2016,2017, approximately $1.0$1.2 million, $4.8$139.5 million, $234.5 million, $54.7$53.7 million, $53.8 million, $3.3 million and $6.7$4.3 million of the principal amount of our indebtedness matures in 2016, 2017, 2018, 2019, 2020, 2021, and thereafter, respectively. Additionally, weWe expect our total interest payment obligations relating to our indebtedness to be approximately $29.5$20.0 million in 2016, $21.62017, $14.4 million of which washad been paid when due as of September 30, 2016.2017.
Although we do not have a specific plan regarding the repurchase, redemption or restructuring of our outstanding indebtedness, weWe generally intend to make payments under our various debt instruments when due and pursue opportunities for earlier repayment and/or refinancing if and when these opportunities arise. With respect to certain of our outstanding indebtedness due in 2018, our board of directors has authorized and approved the use of up to $50.0 million to opportunistically purchase outstanding 5.25% Notes in the open market, in accordance with the terms of the indenture governing the 5.25% Notes and at the date of this report we have used an aggregate $24.9 million for such purchases.
Our ability to make payments of the principal and interest on our indebtedness, whether at or prior to their due dates, depends on our future performance, which is subject to economic, financial, competitive, industry and other factors, including those described in these risk factors, many of which aremay be beyond our control. Our business may not generate cash flow from operations sufficient to service our debt.
If we are, or if we expectIn that we will be, unable to generate such cash flow,case, we may be required to pursue one or more alternatives to meet our debt obligations. For instance, as of the date of this report, we are permitted to repay up to $125.0 million of our outstanding indebtedness at maturity with shares of our common stock rather than cash, with a number of shares to be determined by the then-current trading price of our common stock. Any repayment of our debt with equity would increase the number of our outstanding shares and may significantly dilute the ownership interests of our existing stockholders. Additionally, any shortfall of cash from operations to service our debt may lead us to seek capital from other sources, such as selling assets, restructuring or refinancing our debt or obtaining additional equity capital or debt financing on terms that may be onerous or highly dilutive to our stockholders.financing. Our ability to implementengage in any of these alternatives,activities, should we decide to do so, would depend on the capital markets, the state of our industry and our business and financial condition at the time. Wetime, and we may not be able to engagesuccessful in any of these activities or engage in these activitiesobtaining additional capital on desirable terms, or at a desirable time whichor at all. Any failure to make payments on our debt when due, either in cash or stock, could result in a default on our debt obligations.

Additionally, certain of the agreements governing our indebtedness contain restrictive covenants, and any failure by us to comply with any of these covenants could also cause us to be in default under the agreements governing the indebtedness. In the event of any such default on our debt obligations, the holders of the indebtedness could, among other things, elect to declare all amounts owed immediately due and payable, which could causerequire that we use all or a large portion of our available cash flow to be used to pay such amounts and thereby reduce the amount of cash available to pursue our business plans or force us into bankruptcy or liquidation, or, with respect to our indebtedness that is secured, elect to foreclose on the assets that secure the debt, which would force us to relinquish rights to assets that we may believe are critical to our business.liquidation. In addition, the substantial amount of our indebtedness, combined with our other financial obligations and contractual

commitments, could have other important consequences. For example, it could make us more vulnerable to adverse changes in general U.S. and worldwide economic, industryregulatory and competitive conditions, and government regulations, limit our flexibility to plan for or react to changes in our business and industry, place us at a disadvantage compared to our competitors whothat have less debt or limit our ability to borrow or otherwise raise additional amounts as needed.
At the date of this report, we are permitted to repay up to $150.0 million of our outstanding indebtedness at maturity with shares of our common stock rather than cash, with the amount of shares determined by the then-current trading price of our common stock. Any such issuance would increase the number of our outstanding shares and would dilute the ownership interest of our stockholders.
We may need to raise additional capital to continue to fund the growth of our business or repay our debt.debt, which may not be available when needed, on acceptable terms or at all.
AtAs of September 30, 2016,2017, we had total liquidity of $196.8 million, consisting of cash and cash equivalents of $41.6$45.3 million and short-term investments of $77.3$151.5 million. Our business plan calls for approximately $25.5$29.0 million in capital expenditures for all of 2016,2017, plus an additional $24.0 million by one of our subsidiaries in connection with a specific customer arrangement entered into in June 2017, as well as additional capital expenditures thereafter. We maywill also require capital to make principal orand interest payments on our indebtedness, either prior to or at their maturity dates, or for any unanticipated expenses, and for any mergers, and acquisitions andor strategic investments. As a result,investments, transactions or relationships. If we cannot fund any of these activities with cash provided by our operations, then we may find it necessaryseek to raiseobtain additional capital throughfrom other sources, such as by selling assets or pursuing debt or equity financing.
Asset sales and equity or debt financing options may not be available when needed, on terms favorable to us or at all. Any sale of our assets may limit our operational capacity and could limit or eliminate any revenue streams or business plans that are dependent on the sold assets. Additional issuances of our common stock or securities convertible into our common stock (including through our established at-the-market offering program or other equity offerings) would increase the number of our outstanding shares and dilute the ownership interest of our existing stockholders. We may also pursue debt financing, since, despite the high level of our indebtedness,as the agreements governing much of our existing indebtedness do not restrict our ability to incur additional debt, including secured andor unsecured debt or require us to maintain financial ratios or specified levels of net worth or liquidity. Debt financing options that we may pursue include, among others, equipment financing, sales of convertible notes, high-yield debt, asset-based loans, term loans, project finance debt, municipal bond financing, loans secured by receivables or inventory or commercial bank financing. Any debt financing we obtain may require us to make significant interest payments and to pledge some or all of our assets as security. In addition, higher levels of indebtedness could increase our risk of non-repayment, and could adversely affect our creditworthiness and amplify the other risks associated with our existing debt, which could limit ourare discussed elsewhere in these risk factors and include a limited ability to obtain further debt or equity financing as needed and restrict ourrestricted flexibility in responding to changingany changes in business, industry andor economic conditions. Further, we may incur substantial costs in pursuing any future capital-raising transactions, including investment banking, legal and accounting fees, printing and distribution expenses and other similar costs.fees. On the other hand, if we are unable to obtain capital in amounts sufficient to fund our contractual obligations, business plans, unanticipated expenses, capital expenditures and any mergers, acquisitions or strategic investments, transactions or relationships, we wouldcould be forced to suspend, delay or curtail these plans, expenditures or other transactions,activities, which could negatively affect our business and prospects.
Our success is dependent upon the willingness of fleets and other consumers to adopt natural gas as a vehicle fuel.
Our success is highly dependent upon the adoption by fleets and other consumers of natural gas as a vehicle fuel. If the market for natural gas as a vehicle fuel does not develop as we expectAmerica’s Natural Gas Highway fails or develops more slowly than we expect or if a market does develop but we are not able to capturefuel a significant share of the market or the market subsequently declines, our business, prospects, financial condition and operating results would be harmed.
The market for natural gas as a vehicle fuel is a relatively new and developing market characterized by intense competition, evolving government regulation and industry standards and changing consumer demands and behaviors.
Factors that may influence the adoptiongreater number of natural gas asheavy-duty trucks, our financial results and business would be materially and adversely affected.
We are seeking to fuel a vehicle fuel include, among others:
Increases, decreases or volatility in the prices of oil, gasoline, diesel and natural gas;

The availability and pricegreater number of natural gas compared to gasoline, dieselheavy-duty trucks, and other vehicle fuels;

Natural gas vehicle cost, availability, quality, safety, design and performance, all relative to other vehicles;


Improvements in the efficiency, fuel economy or greenhouse gas emissions of engines for gasoline and diesel-powered and alternative vehicles;

The entry or exit of engine manufacturers into or from the market;

Perceptions about greenhouse gas emissions from natural gas production and transportation methods, natural gas fueling stations and natural gas vehicles;

The availability and acceptance of other alternative fuels and alternative vehicles;

The existence of government programs, policies, regulations or incentives, including tax credits, promoting natural gas and other alternative fuels and alternative vehicles;

Access to natural gas fueling stations and the convenience and cost to fuel a natural gas vehicle;

The availability of service for natural gas vehicles;

The environmental consciousness of fleets and consumers; and

The other risks discussed in these risk factors.

Increases, decreases and general volatility in oil, gasoline, diesel and natural gas prices could adversely impact our business.
In recent years, the prices of oil, gasoline, diesel and natural gasconnection with this effort, we have been volatile, and this volatility may continue. Additionally, prices for crude oil in recent years have been low, due in part to over-production and increased supply without a corresponding increase in demand. Market adoption of compressed natural gas ("CNG"), liquefied natural gas ("LNG") and renewable natural gas ("RNG") (RNG can be delivered in the form of CNG or LNG) as vehicle fuels could be slowed or limited if the low prices and over-supply of gasoline and diesel, today’s most prevalent and conventional vehicle fuels, continue or worsen. The market for natural gas as a vehicle fuel could also suffer if there are further decreases in the prices of gasoline and diesel without an equal and corresponding decrease in the price of natural gas, or if there is an increase in the price of natural gas without equal and corresponding increases in the prices of gasoline and diesel. Any of these circumstances could decrease the market's perception of a need for alternative vehicle fuels generally and could cause the success or perceived success of our industry and our business to materially suffer. Part of the reason that these circumstances could slow or limit adoption of natural gas as a vehicle fuel is the higher cost of natural gas vehicles compared to gasoline or diesel-powered vehicles, as the components needed for a vehicle to use natural gas add to a vehicle’s base cost. If gasoline or diesel prices drop significantly, fuel economy of gasoline- or diesel-powered vehicles improves, or the prices of CNG and LNG are not sufficiently low, operators may delay or refrain from purchasing natural gas vehicles or decide not to convert their existing vehicles to run on natural gas because of a perceived inability to recover in a timely manner the additional costs of acquiring or converting to natural gas vehicles. In addition, in order to attract fleet operators and other consumers to convert to natural gas vehicles, we must be able to offer CNG and LNG fuel at prices lower than gasoline and diesel. Decreases in the price of gasoline and diesel and increases in the price of natural gas make it more difficult for us to offer our customers an attractive pricing advantage for CNG and LNG as compared to gasoline and diesel prices and maintain an acceptable margin on our sales. Further, increased natural gas prices affect the cost to us of natural gas and adversely impact our operating margins in cases where we cannot pass the increased costs through to our customers, and conversely, lower natural gas prices reduce our revenues in cases where the commodity cost is passed through to our customers.
Among the factors that can cause fluctuations in gasoline, diesel and natural gas prices are changes in supply and availability of crude oil and natural gas, inventory levels, level of consumer demand, price and availability of alternative fuels, weather conditions, negative publicity surrounding natural gas drilling techniques and methods or oil production and importing, economic conditions, the price of foreign imports, government regulations and political conditions. With respect to natural gas supply and use as a vehicle fuel, there have been recent efforts to place new regulatory requirements on the production of natural gas by hydraulic fracturing of shale gas reservoirs and other means and on transporting, dispensing and using natural gas.
Hydraulic fracturing and horizontal drilling techniques have resulted in a substantial increase in the proven natural gas reserves in the United States and any changes in regulations that make it more expensive or unprofitable to produce natural gas through these techniques or others, as well as any changes to the regulations relating to transporting, dispensing or using natural gas, could lead to increased natural gas prices.
If the current pricing conditions continue or worsen, or if all or some combination of factors causing further volatility or decreases in natural gas, oil and diesel prices were to occur, our business and our industry would be materially harmed.

If trucks using natural gas engines are not adopted by truck operators as quickly or to the extent we anticipate, our results of operations and business prospects will be adversely affected.
We believe the development and expansion of the U.S. natural gas heavy-duty truck market, and the execution of our initiative to buildbuilt a nationwide network of natural gas-truck friendly fueling stations, which we refer to as "America’s Natural Gas Highway" or "ANGH,"ANGH." depends upon the successfulOur ability to successfully execute these initiatives is subject to substantial risks, including, among others:
The adoption of natural gas engines that are well-suited for useheavy-duty trucks is essential to the success of these initiatives. We have no influence over the development, production, sales and marketing, cost or availability of natural gas trucks powered by heavy-duty trucks. Wethese engines. Currently, Cummins Westport is the only natural gas engine manufacturer for the heavy -duty truck market in the United States, and we have no control over whether and the marketingextent to which Cummins Westport will remain in the natural gas engine business or whether other manufacturers will enter this business.

These initiatives depend upon the development and sales efforts for these engines orexpansion of the success of these efforts, the retail price for these engines or the number of these engines that are ultimately sold. ManufacturersU.S. natural gas heavy-duty truck market. Operators may not produceadopt heavy-duty natural gas engines in meaningful numberstrucks due to cost, actual or as quickly as we anticipate, which could delay theperceived performance issues or other factors that may be beyond our control. To date, adoption and deployment of natural gas trucks by operators. Other factors potentially contributing to slow orhave been slower and more limited adoption of heavy-duty trucks powered by natural gas engines are that these trucks cost more than comparable gasoline or diesel truckswe anticipated.

Truck and other vehicle operators may experience, or be perceived to experience, more operational or performance issues. Our business would be harmed if meaningful numbers of natural gas heavy-duty truck engines are not deployed, if such deployment is slower than expected, or if a substantial number of the trucks that are deployed experience performance issues with their natural gas engines or are not fueledfuel at our stations.stations due to lack of access or convenience, fuel prices or other factors.
The failure of our America’s Natural Gas Highway initiative and our inability to achieve our goal to fuel a substantial number of natural gas heavy-duty trucks would materially and adversely affect our financial results and business.
We are seeking to fuel a substantial number of natural gas heavy-duty trucks and in connection with that effort we are building America’s Natural Gas Highway. Our objectives to fuel a substantial number of heavy-duty trucks and build America’s Natural Gas Highway have required, and will continue to require, a significant commitment of capital and other resources, and our ability to successfully execute these plans faces substantial risks, including, among others:
Most of our ANGH stations were initially built to provide LNG, which costs more than CNG on an energy equivalentenergy-equivalent basis. We have been spending, and expect to continue to spend, additional capital to add CNG fueling capability to many of our ANGH stations, and we may not have sufficient capital in the future for this purpose;purpose, which could limit the revenue-generating capacity of certain of these stations.


Our ANGH stations may experience mechanical or operational difficulties, which could require significant costs to repair and could reduce customer confidence in our stations;

Truck and other vehicle operators may not fuel at our stations due to lack of access or convenience, fuel prices or other factors;

We have no influence over the development, production, cost or availability of natural gas trucks powered by engines that are well-suited for the U.S. heavy-duty truck market. Currently, Cummins Westport is the only natural gas engine manufacturer for the medium- and heavy-duty market, and we have no control over whether and the extent to which Cummins Westport will remain in the natural gas engine business or whether other manufacturers will enter the natural gas engine business;

Operators may not adopt heavy-duty natural gas trucks due to cost, actual or perceived performance issues, or other factors that are outside of our control. To date, adoption and deployment of natural gas trucks have been slower and more limited than we anticipated;stations.

We may not be ablefail to obtain acceptable margins on fuel sales ataccurately predict demand in any of the locations in which we build and open ANGH stations; and

At September 30, 2016,stations. As a result, we had 39 completed ANGHmay open stations that werefail to generate the volume or profitability levels we anticipate and we may build stations that we do not open for fueling operations. We expectoperations, either or both of which could occur due to open these stations when we havea lack of sufficient customerscustomer demand to fuel at the locations,stations or for other reasons. For any stations that are open and underperforming, we may decide to close the stations, which could result in substantial costs, such as lease termination, severance or other similar fees and non-cash asset impairments or other charges, and could harm our reputation and reduce our customer base and prospects for future growth. For any stations that are completed but we do not know when this will occur. If we do not open the stations,unopened, we will continue to have substantial investments in assets that do not produce revenues equal to or greater than their costs, or at all.revenue.

We must effectively manage these risks in order to obtain the anticipated benefits from ANGH and any other risks that may arise in connection with the ANGH build-outachieve our objective of fueling additional natural gas heavy-duty trucks. If we are not able to successfully execute our business plan. If the U.S. market for heavy-duty natural gas trucks does not develop or if we fail to successfully execute our ANGH initiative and fuel a substantial number of natural gas heavy-duty trucks,these initiatives, our financial results, operations and business, andincluding our ability to repay our debt, willwould be materially and adversely affected.

Compliance with greenhouse gas emissions regulations affecting our LNG plants, LNG and CNG fueling stations or CNG, LNG and RNG fuel sales may prove costly and negatively affect our financial performance.

California has enacted laws that require statewide reductions of greenhouse gas emissions to 1990 levels by 2020, 40% below 1990 levels by 2030, and 80% below 1990 levels by 2050. As of January 1, 2015, California's AB 32 law began regulating the greenhouse gas emissions from transportation fuels, including the emissions associated with LNG and CNG vehicle fuel.

AutomobileUnder AB 32, the LNG vehicle fuel provider is the regulated party with respect to LNG vehicle fuel use. We will incur costs to comply with AB 32 based on how much LNG vehicle fuel we sell that is regulated, the requirements of the California Air Resources Board ("CARB") relating to the regulation of LNG vehicle fuel, any applicable regulatory changes and engine manufacturers produce very fewthe cost of carbon credits we purchase to comply with AB 32. We anticipate that we will try to pass the costs we incur to comply with this law through to our LNG customers. With respect to CNG vehicle fuel, the regulated party under AB 32 is the utility that owns the pipe through which the fossil fuel natural gas vehiclesis sold. We anticipate that, over time, as the utilities' compliance costs increase, we or, to the extent we pass these costs through to our customers, our CNG customers will be required to pay more for CNG vehicle fuel to cover the increased AB 32 compliance costs of the utility. The amount of these costs that we or our CNG customers will be required to pay will be determined by the amount the utility spends to buy any carbon credits needed to comply with AB 32 and enginesthe amount of natural gas we or our customers buy through a utility’s pipeline. These increased costs of LNG and CNG vehicle fuel as a result of AB 32 could diminish the attractiveness of LNG and CNG as a vehicle fuel for the United Statesexisting and Canadian markets,potential future California customers, which limitscould reduce our customer base and fuel sales. Additionally, to the extent we are not able to pass costs through to our customers, these increased costs could increase our direct expenses and reduce our margins, which would cause our performance to suffer.

Although our Redeem™ RNG vehicle fuel may qualify for an exemption from AB 32 when sold as LNG or CNG, the availability of any such exemption is uncertain at this time due to the complexity of the requirements that must be met in order to qualify for an exemption and the possibility of changes to the law. Any Redeem™ volumes that are not exempt would incur compliance costs commensurate with sales of CNG and LNG and RNG.derived from fossil fuel natural gas.
Limited availability of natural gas vehicles and engine sizes, including heavy-duty trucks
The federal and other types of vehicles, restricts their large-scale introductionstate governments are also considering measures to regulate and limits our naturalreduce greenhouse gas fuel sales. Limited production could also increase the cost to purchase natural gas vehicles. Original equipment manufacturers produce a relatively small number of natural gas engines and vehicles in the U.S. and Canadian markets and they may not decide to expand, or they may decide to discontinue or curtail, their natural gas engine or vehicle product lines. Additionally, engines that are produced may experience performance issues or be subject to recalls. As a resultemissions. Any of these regulations, if and other factors,when adopted and implemented, may regulate the limited supply of naturalgreenhouse gas vehicles could restrictemissions produced by or associated with our ability to promoteLNG production plants, our CNG and achieve widespread adoption of natural gas vehicles, which could harm our business and prospects.
Our business is influenced by environmental, tax and other government regulations, programs and incentives that promoteLNG fueling stations or encourage cleaner burning fuels and alternative vehicles and their adoption, modification or repeal could impact our business.
Our business is influenced by federal, state and local government tax credits, rebates, grants and similar programs and incentives that promote the use of CNG, LNG and RNG aswe sell, and could require us to obtain emissions credits or invest in costly emissions prevention technology. We cannot estimate the costs that may be required to comply with potential federal, state or local regulation of greenhouse gas emissions, and these unknown costs are not contemplated by our existing customer agreements or our budgets and cost estimates. If any of these regulations are adopted and implemented, any associated compliance costs that we are not able to pass through to our customers may have a vehicle fuel, as well as by laws, rulesnegative impact on our financial performance, reduce our margins, impair our ability to fulfill customer contracts and regulations that require reductions in carbon emissions. Parties with an interest in gasolinereduce our cash available for other aspects of our business, including operating costs, investments and diesel or alternative fuels such as renewable diesel, hydrogen- or electric-powered vehicles, many of which have substantially greater resources and influence than we have, invest significant time and money in efforts to delay, repeal or otherwise negatively influencedebt repayments. Further, these regulations and programs that promoteany increased customer costs may discourage consumers from adopting natural gas as a vehicle fuel. Any failure to adopt, delay in implementing, expiration, repeal or modification of federal, state or local regulations, programs or incentives that encourage the use of CNG, LNG and RNG as a vehicle fuel, or the adoption of any such regulations, programs or incentives that encourage the use of other alternative fuels or alternative vehicles instead of natural gas, could harm our operating results and financial condition. Additionally, changes to or the repeal of laws, rules and regulations that mandate reductions in carbon emissions and/or the use of renewable fuels, including the California and Oregon Low Carbon Fuel Standards and the federal Renewable Fuel Standard Phase 2, under which we generate credits ("LCFS Credits" and "RIN Credits" or "RINs", respectively) by selling CNG, LNG and RNG as a vehicle fuel, could adversely affect our financial condition. Further, our business would be adversely affected if grant funds cease to be available under government programs for the purchase and construction of natural gas vehicles and stations.
We face increasing competition from a variety of businesses, many of which have far greater resources and brand awareness than we have.
A significant number of established businesses, including oil and gas companies, alternative vehicle and alternative fuel companies, refuse collectors, natural gas utilities and their affiliates, industrial gas companies, truck stop and fuel station owners, fuel providers and other organizations have entered or are planning to enter the market for natural gas and other alternatives for use as vehicle fuels. Additionally, for certain of our key customer markets, such as airports and taxis, we indirectly compete with companies such as Uber and Lyft that provide alternative transportation methods. Further, we compete with producers and sellers of gasoline and diesel fuels, which power the vast majority of vehicles in the United States and Canada, suppliers of other alternative vehicle fuels and providers of hybrid and electric vehicles. Many of these current and potential competitors have substantially greater financial, marketing, research and other resources than we have. New technologies and improvements to existing technologies may make alternatives other than natural gas more attractive to the market, or may slow the development of the market for natural gas as a vehicle fuel if such advances are made with respect to oil and gas usage. Natural gas utilities and their affiliates also own and operate natural gas fueling stations that compete with our stations, or are preparing to enter the natural gas vehicle fuel market. Utilities and their affiliates typically have unique competitive advantages, including a lower cost of capital, substantial and predictable cash flows, long-standing customer relationships, greater brand awareness and large and well-trained sales and marketing organizations.
We expect competition to increase in the alternative vehicle fuels market generally and, if the use of natural gas vehicles and the demand for natural gas vehicle fuel increases, the market for natural gas vehicle fuel. Any such increased competition would lead to amplified pricing pressure, reduced operating margins and fewer expansion opportunities.
If there are advances in other alternative vehicle fuels or technologies, or if there are improvements in gasoline, diesel or hybrid engines, demand for natural gas vehicles may decline.
Technological advances in the production, delivery and use of alternative fuels that are, or are perceived to be, cleaner, more cost-effective or more readily available than CNG, LNG or RNG have the potential to slow or limit adoption of natural gas vehicles. Advances in gasoline and diesel engine technology, including efficiency improvements and further development of hybrid engines, may also offer a cleaner, more cost-effective option and make fleet customers less likely to convert their vehicles to natural gas. Technological advances related to ethanol or biodiesel, which are used as an additive to, or substitute for, gasoline and diesel fuel, may slow the need to diversify fuels and affect the growth of the natural gas vehicle fuel market.

Use of electric heavy-duty trucks, buses and refuse trucks, or the perception that such vehicles may soon be widely available and provide satisfactory performance at an acceptable cost, may reduce demand for natural gas vehicles. In addition, renewable diesel, hydrogen and other alternative fuels in experimental or developmental stages may prove to be cleaner, more cost-effective alternatives to gasoline and diesel than natural gas. Advances in technology that slow or curtail the growth of natural gas vehicle purchases or conversions, or that otherwise reduce demand for natural gas as a vehicle fuel would have an adverse effect on our business. Failure of natural gas vehicle technology to advance may also limit its adoption and our ability to compete with gasoline-and diesel-powered vehicles and other alternative fuels and alternative vehicles.
We are subject to risks associated with station construction and similar activities, including difficulties identifying suitable station locations, zoning and permitting issues, local resistance, cost overruns, delays and other contingencies.
In connection with our station construction operations, we may not be able to identify, obtain and retain sufficient permits, approvals and other rights to use suitable locations for the stations we or our customers seek to build. We may also encounter land use or zoning difficulties or local resistance that prohibit us or our customers from building new stations on preferred sites or limit or restrict the use of new or existing stations. Any such difficulties, resistance or limitations could harm our business and results of operations. In addition, we act as the general contractor and construction manager for station construction and facility modification projects and typically rely on licensed subcontractors to perform the construction work. We may be liable for any damage we or our subcontractors cause, or for injuries suffered by our employees or our subcontractors’ employees, during the course of our projects. Shortages of skilled subcontractor labor for our projects could significantly delay a project or otherwise increase our costs. Our profit on our projects is based in part on assumptions about the cost of the projects and cost overruns, delays or other execution issues may, in the case of projects that we complete and sell to customers, result in our failure to achieve our expected margins or cover our costs, and in the case of projects that we build and own, result in our failure to achieve an acceptable rate of return.
Clean Energy Compression's manufacturing operations could subject us to significant costs and other risks, including product liability claims.
Our subsidiary,
Clean Energy Compression designs, manufactures, sells and services non-lubricated natural gas fueling compressors and related equipment used in CNG and LNG fueling stations. The equipment manufactured by Clean Energy Compression produces and sells may fail to perform as expected or according to legal or contractual specifications.specificatio

ns. Additionally, Clean Energy Compression may incur significant and unexpected costs during or after the manufacture of itsthese products, including costs incurred to repair product failures or malfunctions. The scope and likelihood of these risks may increase if Clean Energy Compression makes efforts to expand its services to new geographic and other markets. Further, the success of ourthe compressor business is dependent upon the success of the natural gas vehicle fuels market generally, and is thus subject to many of the other risks described in these risk factors. The occurrence of any of these risks may reduce sales of Clean Energy Compression'scompressor products and services, and revenues to us from this business, damage our customer relationships and reputation, delay the launch of new Clean Energy Compressioncompressor products or services, damage customer relationships and services,reputation, force product recalls and/or result in product liability claims.
Our warranty reserves may not adequately cover our warranty obligations.
We provide product warranties with varying terms and durations for natural gas compressors and stations we build and sell to customers, and we establish reserves for the estimated liability associated with these product warranties. Our warranty reserves are based on historical trends as well as our understanding of specifically identified warranty issues, and the amounts estimated for these reserves could differ materially from the warranty costs that may actually be realized. We would be adversely affected by an increase in the rate of warranty claims or the amounts involved with warranty claim or by the The occurrence of unexpected warranty claims.any of these risks could negatively affect our performance and financial condition.
Increased global IT security threats and more sophisticated and targeted computer crime could pose a risk to our systems, networks, products, solutions and services.
Increased global IT security threats and more sophisticated and targeted computer crime pose a risk to the security of our systems and networks and the confidentiality, availability and integrity of our data. Depending on their nature and scope, such threats could potentially lead to the compromise of confidential information, improper use of our systems and networks, manipulation and destruction of data and operational disruptions.
The global scope of Clean Energy Compression's operations exposes us to additional risks and uncertainties.
Clean Energy Compression hasmanufactures its natural gas fueling compression equipment primarily in Canada and sells this equipment globally through its operations in Canada, the People's Republic of China, Colombia, Bangladesh and Peru. Clean Energy Compression’s natural gas compression equipment is primarily manufactured in Canada and sold globally, whichThe global scope of these operations exposes us to a number of risks and uncertainties that can arise from international trade transactions, local business practices and cultural considerations.

In addition to the other risks described in these risk factors, the global scope of our Clean Energy Compression's operations may subject us to risks and uncertainties that could limit our operations, increase our costs or otherwise negatively impact our business and financial condition,considerations, including, among others:
Failure to comply with the United States Foreign Corrupt Practices Act and other applicable anti-bribery laws;

Political unrest, terrorism, war, natural disasters and economic and financial instability;

Low local prices for locally producedcrude oil, gasoline, diesel, natural gas or diesel;other alternative fuels;

Changes inDiffering environmental and other regulatory requirements and uncertaintyrequirements;

Uncertainty related to developing legal and regulatory systems and standards for economic and business activities, real property ownership and application of contract rights;

Trade restrictions or barriers, including tariffs or other charges, and import-export regulations;regulations, which are subject to increased uncertainty as a result of the outcome of the 2016 U.S. presidential election and the trade policies of the current administration regarding existing and proposed trade agreements and the ability to import goods into the United States;

Difficulties enforcing agreements and collecting receivables;

Difficulties complying with the laws and regulations of multiple jurisdictions;

Difficulties ensuring that health, safety, environmental and other working conditions are properly implemented and/or maintained by local offices;

Differing employment practices and/or labor issues, including wage inflation, labor unrest and unionization policies;

Limited intellectual property protection;

Longer payment cycles by international customers;

Inadequate local infrastructure and disruptions of service from utilities or telecommunications providers, including electricity shortages;

Difficulties forecasting demand and sales trends in foreign markets;

Risks associated with currency exchange and convertibility, including vulnerability to appreciation and depreciation of foreign currencies against the U.S. dollar;

Uncertain repatriation of funds as a result of economic, monetary and regulatory factors in some countries that may affect our ability to convert funds to U.S. dollars or move funds from accounts in these countries; and

Potentially adverse tax consequences.

In addition
These risks and uncertainties could limit our operations, increase our costs or expose us to fines or other legal sanctions or damages, any of which would negatively impact our business and financial condition.

Our RNG business may not be successful.
On March 31, 2017, we completed the above, we also face risks associated with currency exchangesale of certain assets related to our RNG business, including our former RNG production facilities, to BP Products North America, Inc. ("BP"). Following this sale, our RNG business consists of purchasing RNG from BP and convertibility, inflationother third-party producers and repatriation of earningsreselling this RNG through our natural gas fueling infrastructure as a resultRedeem™, our RNG vehicle fuel.

The success of our foreign operations. In some countries, economic, monetary and regulatory factors could affectRNG business depends on our ability to convert fundssecure, on acceptable terms, a sufficient supply of RNG from BP and other third parties, and to United States dollarseither sell this RNG at a substantial premium to conventional natural gas prices or move funds from accounts in these countries. We are also vulnerable to appreciation or depreciation of foreign currencies against the United States dollar, which could negatively impact our operating results and financial performance.
We depend on key people to operate our business, and if we are unable to retain our key people or hire additional qualified people, our ability to develop and successfully market our business would be harmed.
We believe that our future success is highly dependent on the contributions of our executive officers, as well as our ability to attract and retain highly skilled managerial, sales, technical and finance personnel. Qualified individuals are in high demand, andsell, at favorable prices, credits we may incur significant costs to attractgenerate under applicable federal or state laws, rules and retain them.
All of our executive officersregulations, including RINs and other United States employees may terminate their employment relationships with us at any time, and in many cases their knowledge of our business and industry would be extremely difficult to replace.LCFS Credits. If we are unable to retainnot successful at one or more of these activities, our executive officersRNG business could fail and key employees or, if such individuals leave our Company, we are unable to attract and successfully integrate quality replacements, our business, operating resultsperformance and financial condition could be materially harmed.
Our ability to maintain an adequate supply of RNG may be subject to risks affecting RNG production. Projects that produce pipeline-quality RNG often experience unpredictable production levels or other difficulties due to a variety of factors, including, among others, problems with key equipment, severe weather, construction delays, technological difficulties and high costs associated with operations, limited availability or unfavorable composition of collected landfill gas, and plant shutdowns caused by upgrades, expansion or required maintenance. If any of our RNG suppliers experience these or other difficulties, then our supply of, and ability to resell, RNG as a vehicle fuel could be jeopardized.

In addition, our ability to generate revenue from our sale of RNG or our generation and sale of RINs and LCFS Credits depends on a number of factors, including the markets for RNG as a vehicle fuel and for these credits. In the past, the market for RINs and LCFS Credits has been volatile and unpredictable, and the prices for such credits have been subject to significant fluctuations. Additionally, the value of RINs and LCFS Credits, and consequently the revenue levels we may receive from our sale of these credits, may be adversely affected by changes to federal and state programs under which these credits are generated and sold. In addition, our ability to generate revenue from sales of these credits depends upon our strict compliance with these federal and state programs, which are complex and can involve a significant degree of judgment. If the agencies that administer and enforce these programs disagree with our judgments, otherwise determine we are not in compliance or conduct reviews of our activities, then our ability to generate or sell these credits could be temporarily restricted pending completion of reviews or as a penalty, permanently limited or lost entirely, and we could also be subject to fines or other sanctions, any of which could force us to purchase credits in the open market to cover any credits we have contracted to sell, retire credits we may have generated but not yet sold, or eliminate or reduce a significant revenue stream. , and we could also be subject to fines or other sanctions. Further, following our sale to BP of certain assets related to our RNG business, the amount of revenue we generate from sales of RINs and LCFS Credits has decreased, which has and will continue, for at least the near term, to adversely affect our financial results. Moreover, in the absence of federal and state programs that support premium prices for RNG or that allow the generation and sale of LCFS Credits and RINs or other credits, or if our customers are not willing to pay a premium for RNG, we may be unable to operate our RNG business profitably or at all.

We are subject to risks associated with station construction and similar activities, including difficulties identifying suitable station locations, zoning and permitting issues, local resistance, cost overruns, delays and other contingencies.
In connection with our station construction operations, we may not be able to identify suitable locations for the stations we or our customers seek to build. Additionally, even if preferred sites can be located, we may encounter land use or zoning difficulties, challenges obtaining and retaining required permits and approvals or other local resistance, any of which could prevent us or our customers from building new stations on these sites or limit or restrict the use of new or existing stations. Any such difficulties, resistance or limitations or any failure to comply with local permit, land use or zoning requirements could restrict our station construction activity or expose us to fines, reputational damage or other liabilities, which would harm our business and results of operations. In addition, we act as the general contractor and construction manager for station construction and facility modification projects and typically rely on licensed subcontractors to perform the construction work. We may be liable for any damage we or our subcontractors cause or for injuries suffered by our employees or our subcontractors’ employees during the course of our projects. Additionally, shortages of skilled subcontractor labor could significantly delay a project or otherwise increase our costs. Further, our profit from our projects is based in part on assumptions about the cost of the projects, and cost overruns, delays or other execution issues may, in the case of projects we complete and sell to customers, result in our failure to achieve our expected margins or cover our costs, and in the case of projects we build and own, result in our failure to achieve an acceptable rate of return.

We have significant contracts with government entities, thatwhich are subject to unique risks.
We have, and willexpect to continue to seek, long-term CNG, LNG and RNG station construction, maintenance and fuel sales contracts with various government bodies, which accounted for approximately 16%20% of our revenuesrevenue for the nine months ended September 30, 20162017 and approximately 19%18%, 18% and 18%16% of our revenuesrevenue in 2013, 2014, 2015 and 2015,2016, respectively.

In addition to normal business risks, including the other risks discussed in these risk factors, our contracts with government entities are often subject to unique risks, some of which aremay be beyond our control. Long-termFor example, long-term government contracts and related orders are subject to cancellation if adequate appropriations for subsequent performance periods are not made. TheFurther, the termination of funding for a government program supporting any of our government contracts could result in a loss of anticipated future revenuesrevenue attributable to thatthe contract, which could have a negative impact on our operations.
In addition, government entities with which we contract are often able to modify, curtail or terminate contracts with us at their convenience and without prior notice and would only be required to pay for work completed and commitments made at the time of termination. Modification, curtailment or termination of significant government contracts could have a material adverse effect on our results of operations and financial condition. Further, government contracts are frequently awarded only after competitive bidding processes, which are often protracted. In many cases, unsuccessful bidders for government contracts are provided the opportunity to formally protest certainthe contract awards through various agencies or other administrative and judicial channels. The protest process may substantially delay a successful bidder’s contract performance, result in cancellation of the contract award entirely and distract management. As a result, we may not be awarded contracts for which we bid and substantial delays or cancellation of contracts may follow any successful bids as a result of suchthese protests.
Natural gas purchase commitments may exceed demand, which could cause our costs relative to our revenues to increase.
We are a party to two long-term natural gas purchase agreements that have a take-or-pay commitment, and we may enter into additional contracts with take-or-pay commitments in the future. Take-or-pay commitments require us to pay for the natural gas that we have agreed to purchase irrespective of whether we can sell the gas. If the market for natural gas as a vehicle fuel declines or fails to develop as we anticipate, if we lose significant natural gas vehicle fueling customers, or if demand under any existing or any future sales contract does not maintain its volume levels or grow, these commitments may cause our operating and supply costs to increase without a corresponding increase in revenue and our margins and performance may be negatively impacted.
Compliance with greenhouse gas emissions regulations affecting our LNG plants, RNG production facilities, LNG and CNG fueling stations or CNG, LNG and RNG fuel sales may prove costly and negatively affect our financial performance.
California has adopted legislation, AB 32, that calls for a cap on greenhouse gas emissions throughout California and a statewide reduction to 1990 levels by 2020 and an additional 80% reduction below 1990 levels by 2050. Further, in 2015 the Governor of California issued an executive order mandating a reduction in greenhouse gas emissions by 40% compared to 1990 levels by 2030. As of January 1, 2015, AB 32 began regulating the greenhouse gas emissions from transportation fuels, including the emissions associated with LNG and CNG vehicle fuel.
Under AB 32, the LNG vehicle fuel provider is the regulated party with respect to LNG vehicle fuel use. In 2016, we were required to pay $154,560 to comply with AB 32 with respect to our LNG vehicle fuel sales in California. Our costs in future years will depend on how much LNG vehicle fuel we sell that is regulated, the California Air Resources Board's ("CARB") guidance on the regulation of LNG vehicle fuel, potential regulatory changes and the cost of carbon credits we purchase to comply with AB 32 at the time we purchase them. We anticipate that we will pass the costs we incur to comply with this legislation through to our LNG vehicle fuel customers, which may diminish the attractiveness of LNG as a vehicle fuel for California customers. With respect to CNG, the regulated party under AB 32 is the utility that owns the pipe through which the fossil fuel natural gas is sold. SoCalGas, the Southern California gas utility, has recently announced that it intends to charge CNG fueling customers an additional $0.27 per MMBtu of CNG sold to cover its AB 32 compliance costs. We anticipate that we will pass these additional utility fees through to our customers, which may diminish the attractiveness of CNG as a vehicle fuel for California customers. In addition, we anticipate that, over time, as the utilities' compliance costs increase, we or our CNG customers will be required to pay more for CNG vehicle fuel to cover the increased AB 32 compliance costs of the utility. These costs will be determined by the amount the utility spends to buy any carbon credits needed to comply with AB 32 as a result of the natural gas we or our customers buy through the utility’s pipeline.
Although our Redeem™ RNG vehicle fuel may qualify for an exemption from AB 32 when sold as LNG or CNG, the complexity of the requirements that biomethane must meet in order to qualify for an exemption and the possibility of changes to the legislation make any exemption uncertain at this time. Any Redeem™ volumes that are not exempt would incur compliance costs commensurate with sales of CNG and LNG derived from fossil fuel natural gas.
The federal government and other state governments are considering similar measures to regulate and reduce greenhouse gas emissions. Any of these regulations, when and if implemented, may regulate the greenhouse gas emissions produced by our LNG production plants, our CNG and LNG fueling stations or our RNG production facilities, and/or the greenhouse gas emissions associated with the CNG, LNG and RNG we sell, and could require us to obtain emissions credits or invest in costly emissions prevention technology. We cannot currently estimate the potential costs associated with compliance with potential federal, state or local regulation of greenhouse gas emissions and these unknown costs are not contemplated by our current customer agreements or our budgets and cost estimates.

If any of these regulations are implemented, our associated compliance costs may have a negative impact on our financial performance, reduce our margins and impair our ability to fulfill customer contracts, and could also reduce our cash available for other aspects of our business, including operating costs, investments and debt repayments. Further, these regulations may discourage consumers from adopting natural gas as a vehicle fuel.
Our operations entail inherent safety and environmental risks that may result in substantial liability to us.
Our operations entail inherent safety risks, including risks associated with equipment defects, malfunctions, failures and misuses, any of which could result in uncontrollable flows of natural gas, fires, explosions andor other damage.damage, including death or serious injury. For example, operation of LNG pumps requires special training because of the extremely low temperatures of LNG. Also, LNG tanker trailers have in the past been, and may continue to be,CNG fuel tanks and trailers, if involved in accidents that result in explosions, fires and other damage.or improper maintenance or installation, could rupture. Further, refueling of natural gas vehicles or operation of natural gas vehicle fueling stations could result in venting of methane gas, which is a potent greenhouse gas, and such methane emissions are currently regulated by some state regulatory agencies and may in the future be regulated by the U.S. Environmental Protection Agency and/or by additional state regulators. Additionally, CNG fuel tanks and trailers, if damaged by accidents or improper maintenance or installation, may rupture and the contents of the tank or trailer may rapidly decompress and result in death or serious injury. These safety and environmental risks may expose us to liability for personal injury, wrongful death, property damage, pollution and other environmental damage. We may incur substantial liability and costs if damages are not covered by insurance or are in excess of policy limits. Moreover,limits or if environmental damage causes us to violate applicable greenhouse gas emissions or other environmental laws. Additionally, the occurrence of any of these occurrencesevents with respect to our fueling stations or our other operations could materially harm our business and reputation. Moreover, the occurrence of any of these events to any other organization in the natural gas vehicle fuel business could harm our reputation, our businessindustry generally by negatively affecting perceptions about and adoption levels of natural gas generally.as a vehicle fuel.
We provide financing to fleet customers for natural gas vehicles, which exposes our business to credit risks.
We lend to certain qualifying customers a portion and occasionally up to 100% of the purchase price of natural gas vehicles they agree to purchase. Risks associated with these financing activities include, among others, that: the equipment financed consists mostly of vehicles that are mobile and easily damaged, lost or stolen; and the borrower may default on payments, enter bankruptcy proceedings and/or liquidate. At September 30, 2016, we had $13.2 million outstanding in loans provided to customers to finance natural gas vehicle purchases.
Our business is subject to a variety of government regulations that may restrict our operations and result in costs and penalties.
We are subject to a variety of federal, state and local laws and regulations relating to the environment, health and safety, labor and employment, building codes and construction, zoning and land use, foreign business practices and taxation, among others. Additionally, we are subject to changing and complex regulations related to the government procurement process, and any political activities or lobbying relating to natural gas or greenhouse gas emissions regulations in which we may engage.engage, foreign business practices, public reporting and taxation, among others. It is difficult and costly to manage the requirements of every individual authority having jurisdiction over our various activities and to comply with thesetheir varying standards. These laws and regulations are complex, change frequently and in many cases have tended to become more stringent over time. Any changes to existing regulations or adoption of new regulations may result in significant additional expense to us andor our customers. Further, from time to time, as part of the regular evaluation of our operations, including newly acquired or developing operations, we may be subject to compliance audits by regulatory authorities, which may distract management from our revenue-generating activities and involve significant costs and use of other resources. Also, in connection with our operations, we often need to obtain facility permits or licenses to address, among other things, storm water or wastewater discharges, waste handling and air emissions, which may subject us to onerous or costly permitting conditions.conditions or delays if permits cannot be timely obtained.

Our failure to comply with any applicable laws and regulations may result in a variety of administrative, civil and criminal enforcement measures, including assessment of monetary penalties, the imposition of corrective requirements or prohibition from providing services to government entities.
Our RNG business may not be successful.
We own RNG production facilities located in Canton, Michigan and North Shelby, Tennessee. We are also seeking to increase our RNG business by pursuing additional projects on our own and with project partners.
We may not be successful in operating or developing these projects orentities, any future projects or generating a financial return from our investments. Historically, projects that produce pipeline-quality RNG have often failed due to the volatile prices of conventional natural gas, unpredictable RNG production levels, technological difficulties and costs associated with operating the production facilities and a general lack of government programs and regulations that support these activities.
The success of our RNG business depends on our ability to obtain necessary financing, to successfully manage the construction and operation of our RNG production facilities, to enter into RNG supply agreements with third parties, and to either sell RNG at substantial premiums to conventional natural gas prices or to sell, at favorable prices, credits we may generate under

federal or state laws, rules and regulations, including RINs and LCFS Credits. If we are not successful at one or more of these activities, our RNG businesswhich could fail.
The market for RINs and LCFS Credits is volatile, and the prices for these credits are subject to significant fluctuations. We have entered into futures contracts for the sale of specified amounts of RINs over specified periods and at fixed prices. These futures contracts subject us to risks based on fluctuations in the prevailing market price for RINs, since we could be forced to purchase RINs in the open market if we are not able to produce sufficient RINs through our operations to satisfy our obligations under these futures contracts.
The value of RINs and LCFS Credits may be adversely affected by any changes to federal and state programs under which these credits are generated and sold. For example, CARB recently raised the carbon intensity rating of the RNG we sell in California, which will reduce the amount of LCFS Credits we generate and could adverselynegatively affect our RNG business and our financial results. Additionally, in the absence of federal and state programs that support premium prices for RNG or that allow us to generate and sell LCFS Credits and RINs or other credits, or if our customers are not otherwise willing to pay a premium for RNG, we may be unable to profitably operate our RNG business.
We have experienced, and may continue to experience, difficulties producing RNG.
We have experienced difficulties producing the expected volumes of RNG at our RNG plants due to, among other factors, problems with key equipment, severe weather, landfill conditions and construction delays. These difficulties may continue or worsen in the future. Additionally, our ability to produce RNG may be adversely affected by a number of other factors, including, among others, limited availability or unfavorable composition of collected landfill gas, failure to obtain and renew necessary permits and landfill mismanagement. In addition, we may seek to or be required to upgrade, expand or service our RNG facilities, which may result in plant shutdowns, cause delays that reduce the amount of RNG we produce or involve significant unexpected costs.performance.
We may from time to time pursue acquisitions, divestitures, investments or other strategic relationships or transactions, which could fail to meet expectations.expectations or otherwise harm our business.

We may acquire or invest in other companies or businesses or pursue other strategic transactions or relationships. Acquisitions, investments andrelationships, such as joint ventures, collaborations or other strategic partnerships and relationshipssimilar arrangements. For example, in March 2017 we sold certain assets related to our RNG business, including our former RNG production facilities. These transactions involve numerous risks, any of which could harm our business, including, among others:

Difficulties integrating the technologies, operations, existing contracts, personnel and personnel of an acquired company or partner;

Difficulties supporting and transitioning vendorsservice providers of an acquired company or partner;

Diversion of financial and management resources from existing operations or alternative acquisition, investment or investmentother opportunities;

Failure to realize the anticipated benefits or synergies of a transaction or relationship;

Failure to identify all of the problems, liabilities, shortcomings or challenges of a company or technology we may partner with, invest in or acquire, including issues related to intellectual property rights, regulatory compliance practices, revenue recognition or other accounting practices or employee, customer or customervendor relationships;

Risks of entering new customer or geographic markets in which we may have limited or no experience;

Potential loss of an acquired company’s, business’ or partners’ key employees, customers or vendors in the event of an acquisition or investment, or potential loss of our assets, employees or customers in the event of a divestiture or other similar strategic transaction;

Risks associated with any joint venture or other collaboration relationship we may pursue, including as a result of our relinquishment of some degree of control over the assets, technologies or businesses that are the subject of the joint venture or collaboration, or as a result of our partners having business goals and vendors from an acquired company’sinterests that are not aligned with ours or partner’s business;being unable or unwilling to fulfill their obligations in the relationship;

Inability to generate sufficient revenue to offset costs related to an acquisition, investment or other related costs;transaction or relationship;

Additional costs, or incurrence of debt or equity dilution associated with funding an acquisition, investment or other transaction or relationship; and

Possible write-offs or impairment charges relating to theany businesses we partner with, invest in or acquire.

Our quarterly results of operations fluctuate significantly and are difficult to predict.

Our quarterly results of operations have historically experienced, significant fluctuations and may continue to fluctuate significantlyexperience, significant fluctuations as a result of a variety of factors, including, among others, the amount and timing of compressor and other equipment sales, station construction sales, sales of RINs and LCFS Credits, and recognition of VETCany other government credits and, compressor and other credits,equipment sales; fluctuations in commodity costs

and natural gas prices and sale activityactivity; and the amount and timing of our billing, collections and liability payments, as well as the other factors described in these risk factors. If our quarterly results of operations fall below the expectations of securities analysts or investors, the price of our common stock could decline substantially.
As a result of the
The significant fluctuations of our operating results in priorcertain periods period- to-periodmay render period-to-period comparisons of our operating results may not beless meaningful, and investors in our common stocksecurities should not rely on the results of any one quarterperiod as an indicator of future performance. For example, inour results for the quarterly periodsnine months ended March 31, 2016, JuneSeptember 30, 2016 and September 30, 2016, our results2017 were positively affected by gains related to repurchases or retirements of our outstanding convertible debt, and suchour results for the nine months ended September 30, 2017 were also positively affected by a gain related to our sale of certain assets related to our RNG business, but our results for the nine months ended September 30, 2017 were also negatively affected by significant charges in connection with our closure of certain fueling stations, the decreased operating performance of our natural gas fueling compressor business, our determination of an impairment of assets as a result of the foregoing, and certain other actions.
These or other gains or losses may not recur regularly, in the same amounts or at all in future periods.
We depend on key people to generate our strategies and operate our business, and our business could be harmed if we are unable to retain these key people.


We believe our future success is dependent upon the contributions of our officers and directors and certain other key managerial, sales, technical and finance personnel. All of our officers and other United States employees may terminate their employment relationships with us at any time. Additionally, our directors may resign at any time or fail to be re-elected by our stockholders on an annual basis. In many cases, we believe these individuals’ knowledge of our business and experience in our industry would be extremely difficult to replace. Qualified individuals are in high demand, and we may incur significant costs to attract and retain our key people. If we are unable to retain our officers, directors and other key employees, or if these individuals leave our Company and we are unable to attract and successfully integrate quality replacements in a timely manner, our business, operating results and financial condition could be harmed.

Natural gas purchase commitments may exceed demand, which could cause our costs relative to our revenue to increase.
We are a party to two long-term natural gas purchase agreements with a take-or-pay commitment, and we may enter into additional similar contracts in the future. Take-or-pay commitments require us to pay for the natural gas we have agreed to purchase, irrespective of whether we sell the gas. If the market for natural gas as a vehicle fuel declines or fails to develop as we anticipate, if we lose significant natural gas vehicle fueling customers, or if demand under any existing or future sales contract does not maintain its volume levels or grow, these take-or-pay commitments may exceed our natural gas demand. In that case, our operating and supply costs could increase without a corresponding increase in revenue, which could cause our margins and performance to be negatively impacted.
We provide financing to fleet customers for natural gas vehicles, which exposes our business to credit risks.
We lend to certain qualifying customers a portion, and occasionally all, of the purchase price of natural gas vehicles they agree to purchase. These financing activities involve a number of risks, including, among others, that the equipment financed consists mostly of vehicles, which are mobile and easily damaged, lost or stolen; and the borrower may default on payments, enter bankruptcy proceedings and/or liquidate. As of September 30, 2017, we had $8.3 million outstanding in loans provided to customers to finance natural gas vehicle purchases.

Our warranty reserves may not adequately cover our warranty obligations, which could result in unexpected costs.
We provide product warranties with varying terms and durations for the stations we build and sell and, the natural gas fueling compressors Clean Energy Compression manufactures and sells, and we establish reserves for the estimated liability associated with these product warranties. Our warranty reserves are based on historical trends as well as our understanding of specifically identified warranty issues, and the amounts estimated for these reserves could differ materially from the warranty costs that may actually be realized. We would be adversely affected by an increase in the rate of warranty claims or the amounts involved in warranty claims or by the occurrence of unexpected warranty claims, any of which could increase our costs beyond our established reserves and cause our cash position and financial condition to suffer.

Increased global IT security threats and more sophisticated and targeted computer crime pose a risk to our systems, networks, products, solutions and services.
Increased global IT security threats and more sophisticated and targeted computer crime pose a risk to the security of our systems and networks and the confidentiality, availability and integrity of our data. Implementing security measures designed to prevent, detect, rectify or correct these threats involves significant costs, and any such measures could fail. Depending on their nature and scope, such threats could potentially lead to the compromise of confidential information, improper use of our systems and networks, manipulation and destruction of data, operational disruptions and substantial financial outlays. The occurrence of any of these risks could materially harm our business, reputation and performance.

Risks Related to Our Common Stock
Sales of sharesour common stock, or the perception that such sales may occur, could cause the market price of our stock to drop significantly, even ifregardless of the state of our business is doing well.business.
As of September 30, 2016,2017, there were 134,235,058151,009,700 shares of our common stock outstanding, 11,582,0919,648,613 shares underlying outstanding stock options, 2,432,9302,403,266 shares underlying outstanding restricted stock units, 1,000,000and 14,991,521 shares underlying outstanding warrants (all of which were exercised on a cashless basis subsequent to September 30, 2016, resulting in our issuance of an aggregate of 997,740convertible notes (assuming conversion at the stated conversion price). All outstanding shares of our common stock) and 21,006,491 shares underlying outstanding convertible notes. All of our outstanding sharesstock are eligible for sale in the public market, subject in certain cases to the requirements of Rule 144 ofunder the Securities Act of 1933, as amended ("Securities(the "Securities Act"). Also, shares issued upon the exercise, vesting and settlement or conversion of outstanding stock options, warrantsrestricted stock units and convertible notes aremay be eligible for sale in the public market, to the extent permitted by Rule 144 and the provisions of the applicable stock option, warrantrestricted stock unit and convertible note agreements and Rule 144, or if such shares have been

registered for resale under the Securities Act. If these shares are sold, or if it is perceived that they may be sold, in the public market, the trading price of our common stock could decline.
As of September 30, 2016, 15,941,8602017, 13,010,978 shares of our common stock held by our co-founder and board member T. Boone Pickens were pledged as security for loans made to Mr. Pickens. We are not a party to these loans. If the price of our common stock declines, Mr. Pickens may be forced to provide additional collateral for the loans or to sell shares of our common stock in order to remain within the margin limitations imposed under the terms of the loans. Any sales of our common stock following such a margin call that is not satisfied, or any other large sales of our common stock by our officers andor directors, such as Mr. Pickens' sale of 1,500,000 shares of our common stock in August 2016, may cause the price of our common stock to decline.
A significant portion of our common stock is beneficially owned by a single stockholder whose interests may differ from yours and who is able to exert significant influence over our corporate decisions, including a change of control.
As of September 30, 2016, our co-founder and board member T. Boone2017, Mr. Pickens beneficially owned approximately 14.9%10.6% of our common stock (including 15,941,86013,010,978 outstanding shares of common stock, 725,000 shares underlying exercisableoutstanding stock options and 4,113,9232,531,645 shares underlying outstanding convertible promissory notes). As a result, Mr. Pickens is able to influence or control matters requiring approval by our stockholders, including the election of directors and mergers, acquisitions or other extraordinary transactions. Mr. Pickens may have interests that differ from yours and may vote in a wayways with which you disagree and that may be adverse to your interests. This concentration of ownership may also have the effect of delaying, preventing or deterring a change of control of our Company, which could deprive our stockholders of an opportunity to receive a premium for their shares of our common stock as part of a sale of our Company and mightcould affect the market price of our common stock. Conversely, this concentration of ownership may facilitate a change of control at a time when you and other investors may prefer not to sell.
The price of our common stock may fluctuate significantly, and you could lose all or part of your investment.
The market price of our common stock has experienced, and may continue to experience, significant volatility. SuchThis volatility may be in response to various factors some of whichthat are beyond our control. In addition to the other factors discussed in these risk factors, factorsFactors that may cause volatility in the price of our common stock price include, among others:
Volatility in the supply, demand, use and price of crude oil, natural gas and alternative fuels, including renewable diesel biodiesel, ethanol, electricity and hydrogen;

Expected adoption of and growth of the market for natural gas as a vehicle fuel and our ability to capture a substantial share of and enhance our leadership position within this market, when and if it expands;

Development, commercial availability and adoption of new natural gas engines for the U.S. heavy-duty truck market;

Successful implementationImplementation of our business plans and initiatives, including without limitation, our initiatives to build ANGH initiative and our goal to fuel a substantialgreater number of natural gas heavy-duty trucks;


Continued difficulties producing RNGFailure to meet or exceed financial estimates and other risks to our RNG business;projections of the investment community;

Investor perception of our industry or our prospects;

FluctuationsIncreasing competition in our operating results;

Changes in our key personnel;

A significant number of established businesses, including oil and gas companies, alternative vehicle and alternative fuel companies, refuse collectors, natural gas utilities and their affiliates and other organizations, some of which have substantially greater financial, marketing and other resources than we have, have entered or are planning to enter the market for natural gas and other alternatives for use as vehicle fuels;

Other competitive developments, including advancementsadvances or improvements in conventional fuels and other alternativenon-natural gas vehicle fuels or engines powered by these fuels;

Changes to the availability or effect on our business of environmental, tax or other regulations, programs or incentives that promote natural gas as a vehicle fuel, including, among others, VETC and technologies, such as improvements in the efficiency, fuel economyprograms under which we generate and sell LCFS Credits and RINs;

Adoption of government policies or greenhouseprograms that favor vehicles or vehicle fuels other than natural gas, emissions of enginesincluding long-standing support for conventionalgasoline and alternative fueldiesel-powered vehicles and growing support for electric and hydrogen-powered vehicles;

Changes to emissions requirements on traditionalapplicable to vehicles powered by gasoline, and diesel, powered vehicles,natural gas or other vehicle fuels, as well as on LNG and CNG production, fueling stations and fuel sales, and the impact of emissions and other environmental regulations and pressures on crude oil and natural gas supply;drilling, production, importing or transportation methods and fueling stations for these fuels;

The market's perception of the success and importance of any acquisitions, divestitures, investments or other strategic relationships or transactions we may announce;

Changes in political, regulatory, economic and market conditions;

Changes to the availabilityour management, including officer or impact of federal tax attributes, credits and incentives on our business;

Changes in general economic and market conditions.director departures or other changes;

Sales of our common stock by us or our officers, or directors or significant stockholders; and


A decline in the trading volume of our common stock.stock; and

The other risks described in these risk factors, including the factors that may influence the adoption of natural gas as a vehicle fuel generally.

In addition, the securities markets have from time to time experienced significant price and volume fluctuations that are unrelated to the operating performance of particular companies, and in such instances,but which have affected the market prices of these companies’ securities. These market fluctuations may also materially and adversely affect the market price of our common stock. Moreover, volatility or declines in the market price of our common stock could have other negative consequences, including, among others, potential impairments to our assets or goodwill or a reduced ability to use our common stock for capital-raising, acquisition or other purposes, which could materially and adversely affect our financial condition, results of operations and liquidity and could cause further declines in the market price of our common stock.

Item 2.—Unregistered Sales of Equity Securities and Use of Proceeds
None.
Item 3.—Defaults upon Senior Securities
None.
Item 4.—Mine Safety Disclosures
None.
Item 5.—Other Information
On October 31, 2016,As previously reported, on September 15, 2017, Peter J. Grace retired from his position as our Senior Vice President, Sales & Finance. In connection with Mr. Grace’s retirement, on September 15, 2017, we entered into a Loan Modificationretirement agreement with Mr. Grace, pursuant to which, among other things, (a) Mr. Grace’s Amended and Restated Employment Agreement dated December 31, 2015 (the “Prior Employment Agreement”) was terminated, subject to the survival of certain confidentiality, non-solicitation and other similar provisions, and (b) subject to Mr. Grace’s delivery of a release of claims (subject to his statutory rights) and agreement to comply with Plains solelycertain additional non-disparagement, confidentiality and other similar covenants, we agreed: (i) to pay to Mr. Grace retirement compensation in the amounts set forth in Section 5(d)(i), (ii) and (iii) of the Prior Employment Agreement, generally consisting of a cash payment of $675,000, equal to 150% of Mr. Grace’s annual base salary as of the effective date of his retirement, a cash payment of $540,000, equal to 150% of Mr. Grace’s annual performance bonus for 2016, a cash payment equal to Mr. Grace’s annual performance bonus for 2017, which amount will be determined in 2018 by the purposeCompensation Committee of extendingour Board of Directors consistent with its customary practice; (ii) to transfer to Mr. Grace title to the Credit Facility's maturitycompressed natural gas vehicle we had furnished to Mr. Grace during the term of his employment; (iii) to accelerate the vesting of all of Mr. Grace’s restricted stock units that were outstanding and unvested as of the effective date of his retirement, covering 94,985 shares, and (iv) to accelerate the vesting of all of Mr. Grace’s stock options that were outstanding and unvested as of the effective date of his retirement, totaling options to purchase up to 187,867 shares of our common stock at exercise prices ranging from February 28, 2017$2.83 to September 30, 2018.$6.33 per share, and extend the post-termination exercise period for these options to the original termination date for each such stock option.

Item 6.—Exhibits
The information required by this Item 6 is set forth on the exhibit indexExhibit Index that immediately follows the signature page to this report and is incorporated herein by reference.

SIGNATURE
Pursuant to the requirements of the Securities and Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.
 CLEAN ENERGY FUELS CORP.
  
Date: November 3, 20162, 2017By:/s/ ROBERT M. VREELAND
  Robert M. Vreeland
  
Chief Financial Officer
(Principal financial officer and duly authorized to sign on behalf of the registrant)


EXHIBIT INDEX
 
Exhibit Number Description
   
10.11510.121* Form of 7.5% Notes Exchange


   
10.116*10.122* Loan Modification


10.123*

   
31.1* 
   
31.2* 
   
32.1** 
   
101* The following materials from the Company’s Quarterly Report on Form 10-Q for the quarter ended September 30, 2016,2017, formatted in XBRL (eXtensible Business Reporting Language):
   
  (i) Condensed Consolidated Balance Sheets at December 31, 20152016 and September 30, 2016;2017;
  (ii) Condensed Consolidated Statements of Operations for the Three and Nine Months Ended September 30, 20152016 and 2016;2017;
  (iii) Condensed Consolidated Statements of Comprehensive LossIncome for the Three and Nine Months Ended September 30, 20152016 and 2016;2017;
  (iv) Condensed Consolidated Statements of Cash Flows for the Nine Months Ended September 30, 20152016 and 2016;2017; and
  (v) Notes to Condensed Consolidated Financial Statements.

* Filed herewith.
** Furnished herewith.



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