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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 March 31, 2012

Commission File Number: 001-33480

CLEAN ENERGY FUELS CORP.

(Exact name of registrant as specified in its charter)

3020 Old Ranch Parkway, Suite 400, Seal Beach CA 90740

(Address of principal executive offices, including zip code)

(562) 493-2804

(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” in Rule 12b-2 of the Exchange Act. (Check one):

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 May 1, 2012, there were 86,588,898 shares of the registrant’s common stock, par value $0.0001 per share, issued and outstanding.

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CLEAN ENERGY FUELS CORP. AND SUBSIDIARIES

INDEX

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PART I.—FINANCIAL INFORMATION

Item 1.—Financial Statements (Unaudited)

Clean Energy Fuels Corp. and Subsidiaries

Condensed Consolidated Balance Sheets

December 31, 2011 and March 31, 2012 (Unaudited)

(In thousands, except share data)

See accompanying notes to condensed consolidated financial statements.

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Clean Energy Fuels Corp. and Subsidiaries

Condensed Consolidated Statements of Operations

For the Three Months Ended March 31, 2011 and 2012

(Unaudited)

(In thousands, except share and per share data)

See accompanying notes to condensed consolidated financial statements.

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Clean Energy Fuels Corp. and Subsidiaries

Condensed Consolidated Statements of Comprehensive Income

For the Three Months Ended March 31, 2011 and 2012

(Unaudited)

(In thousands)

See accompanying notes to condensed consolidated financial statements.

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Clean Energy Fuels Corp.

Condensed Consolidated Statements of Cash Flows

For the Three Months Ended March 31, 2011 and 2012

(Unaudited)

(In thousands)

See accompanying notes to condensed consolidated financial statements.

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Clean Energy Fuels Corp. and Subsidiaries

Notes to Condensed Consolidated Financial Statements

(Unaudited)

(In thousands, except share data)

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”) is engaged in the business of selling natural gas fueling solutions to its customers, primarily in the United States. The Company began selling certain equipment and services internationally in 2010 as a result of its acquisition of I.M.W. Industries, Ltd. (“IMW”).

The Company has a broad customer base in a variety of markets, including trucking, airports, taxis, refuse, and public transit. The Company, builds, operates, maintains or supplies approximately 300 natural gas fueling locations in twenty-six states within the United States, and in British Columbia and Ontario within Canada. The Company also generates revenue through operation and maintenance (“O&M”) agreements with certain customers, through building and selling or leasing natural gas fueling stations to its customers, through manufacturing and servicing natural gas fueling compressors and related equipment, providing natural gas vehicle conversions, processing and selling renewable natural gas (“RNG”), and through financing its customers’ vehicle purchases.

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 and cash flows for the three months ended March 31, 2011 and 2012. All intercompany accounts and transactions have been eliminated in consolidation. The three month periods ended March 31, 2011 and 2012 are not necessarily indicative of the results to be expected for the year ending December 31, 2012 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, 2011 that are included in the Company’s Annual Report on Form 10-K filed with the SEC on March 12, 2012.

Use of Estimates:  The preparation of consolidated financial statements in conformity with US GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and revenues and expenses recorded during the reporting period. Actual results could differ from those estimates. Current economic conditions may require the use of additional estimates and these estimates may be subject to a greater degree of uncertainty as a result of the uncertain economy.

Note 2—Acquisitions

Natural Gas Fueling Compressors

On September 7, 2010, the Company, acting through certain of its subsidiaries, completed its purchase of the advanced natural gas fueling compressor and related equipment manufacturing and servicing business of IMW. IMW manufactures and services advanced, non-lubricated natural gas fueling compressors and related equipment for the global natural gas fueling market. IMW is headquartered near Vancouver, British Columbia, and has other manufacturing facilities near Shanghai, China and in Ferndale, Washington, and has sales and service offices in Bangladesh, Colombia, Peru and the United States.

In connection with the closing of the Company’s acquisition of IMW, a subsidiary of the Company (the “Acquisition Subsidiary”) paid an upfront cash payment of $15,034 and issued 4,017,408 shares of the Company’s common stock at closing to IMW’s shareholder. The issued shares were registered and available for immediate resale by the IMW shareholder. An additional $288 was paid by the Acquisition Subsidiary when the Chinese regulatory authorities subsequently approved the transfer of IMW Compressors (Shanghai) Co. Ltd. to the Acquisition Subsidiary. The Acquisition Subsidiary also issued the following promissory notes to the IMW shareholder (collectively, the “IMW Notes”): (i) a promissory note with a principal amount of $12,500 that was paid

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on January 31, 2011, (ii) a promissory note with a principal amount of $12,500 that was due and payable on January 31, 2012, (iii) a promissory note with a principal amount of $12,500 that is due and payable on January 31, 2013, and (iv) a promissory note with a principal amount of $12,500 that is due and payable on January 31, 2014. Each payment under the IMW Notes will consist of $5,000 in cash and $7,500 in cash and/or shares of the Company’s common stock (the exact combination of cash and/or stock to be determined at the Company’s option). In addition, pursuant to a security agreement executed at closing, the IMW Notes are secured by a subordinate security interest in IMW. On January 31, 2011, the Company paid $5,000 in cash and issued 601,926 shares to the IMW shareholder to settle the IMW Note due on that date. On January 31, 2012, the Company paid $5,000 in cash and extended the additional payment due on January 31, 2012 to July 31, 2012.

IMW’s former shareholder may also receive additional contingent consideration based on future gross profits earned by IMW over the four year period following the acquisition. The additional contingent consideration is subject to achieving minimum gross profit targets and will be determined based on a sliding scale that increases at certain gross profit levels. During the four-year period during which these earn-out payments may be made, the former shareholder of IMW will receive between zero and 23% of the gross profit of IMW as additional consideration, up to a maximum of $40,000 in the aggregate (which maximum would be payable if IMW achieves approximately $174,000 in gross profit over the four-year period during which these earn-out payments may be made). The IMW shareholder earned $235 for the first contingent consideration payment.

The Company accounted for this acquisition in accordance with FASB authoritative guidance for business combinations, which requires the Company to recognize the assets acquired and the liabilities assumed, measured at their fair values, as of the date of acquisition. The following table summarizes the allocation of the aggregate purchase price to the fair value of the assets acquired and liabilities assumed:

Management allocated approximately $81,400 of the purchase price to the identifiable intangible assets related to technology, customer relationships, non-compete agreements, and trademarks that were acquired with the acquisition. The fair value of the identifiable intangible assets will be amortized on a straight-line basis over their estimated useful lives ranging from three to twenty years. In addition, management allocated $45,049 to goodwill as part of the acquisition and recorded a contingent liability of $9,300 related to the additional contingent consideration described above. Under FASB authoritative guidance, the Company is required to adjust the value of the contingent consideration for this acquisition in the statement of operations as the value of the obligation changes each reporting period. As of March 31, 2012, the fair value of the contingent consideration was approximately $3,330.

The results of operations of IMW have been included in the Company’s consolidated financial statements since September 7, 2010.

Liquefied Natural Gas Station Construction

On December 15, 2010, the Company acquired Northstar, a leading provider of design, engineering, construction and maintenance services for liquefied natural gas (“LNG”) and liquefied to compressed (“LCNG”) fueling stations. The purchase price primarily consisted of a closing cash payment in the amount of $7,414. The remaining consideration consists of five annual payments in the amount of $700 each commencing on the first anniversary of the closing date, and up to $4,000 in retention bonuses to certain key employees to be paid in four annual installments commencing on the first anniversary of the closing date. In December 2011, the Company made its first annual payment of $700 and paid an installment of $990 in retention bonuses to certain key employees.

The following table summarizes the estimated fair values of the assets acquired and liabilities assumed as of December 15, 2010:

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Management allocated $2,250 of the purchase price to the identifiable intangible assets related to non-compete agreements, customer relationships, and backlog. The fair value of these identifiable intangibles will be amortized on a straight-line basis over their estimated useful lives ranging from one to ten years. The Company also allocated $1,100 of the purchase price to trademarks, which management believes has an indefinite useful life. In addition, management allocated $5,228 to goodwill as part of the acquisition.

The results of Northstar’s operations have been included in the Company’s consolidated financial statements since December 15, 2010.

Note 3—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.

Note 4—Restricted Cash

The Company classifies restricted cash as 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. Restricted cash consisted of the following as of December 31, 2011 and March 31, 2012:

Note 5—Investments

Available-for-sale investments are carried at fair value, inclusive of unrealized gains and losses. Net 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 investments are recognized on the specific identification basis.

Available-for-sale securities as of March 31, 2012 are summarized as follows:

The Company had no available-for-sale securities as of March 31, 2011.

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Note 6—Derivative Transactions

The Company marks to market its open futures positions at the end of each period and records the net unrealized gain or loss during the period in derivative (gains) losses in the condensed consolidated statements of operations or in accumulated other comprehensive income in the condensed consolidated balance sheets in accordance with applicable accounting guidance. The Company recorded unrealized (gains) losses of $(708) and $(715), in other comprehensive income (loss) for the three month periods ended March 31, 2011 and 2012, respectively, related to its futures contracts. Of the $1,543 liability for the Company’s futures contracts at March 31, 2012, $1,496 is included in accrued liabilities for the short-term amount, and $47 is included in other long-term liabilities for the long-term amount in the Company’s condensed consolidated balance sheet as of March 31, 2012. Of the $3,363 liability for the Company’s futures contracts at March 31, 2011, $2,851 is included in accrued liabilities for the short-term amount, and $512 is included in other long-term liabilities for the long-term amount in the Company’s condensed consolidated balance sheet as of March 31, 2011. The Company’s ineffectiveness related to its futures contracts during the three month periods ended March 31, 2011 and 2012 was insignificant. For the three months ended March 31, 2011 and 2012, the Company recognized a loss of approximately $751 and $1,107, respectively, in cost of sales in the accompanying condensed consolidated statement of operations related to its futures contracts that were settled during the respective periods.

The following table presents the notional amounts and weighted-average fixed prices per gasoline gallon equivalent of the Company’s natural gas futures contracts as of March 31, 2012:

Note 7—Other Receivables

Other receivables at December 31, 2011 and March 31, 2012 consisted of the following:

Note 8—Inventories

Inventories are stated at the lower of cost or market on a first-in, first-out basis. Management’s estimate of market includes a provision for slow-moving or obsolete inventory based upon inventory on hand and forecasted demand.

Inventories consisted of the following as of December 31, 2011 and March 31, 2012:

Note 9—Land, Property and Equipment

Land, property and equipment at December 31, 2011 and March 31, 2012 are summarized as follows:

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Note 10—Investments in Other Entities

Through March 31, 2012, the Company has invested approximately $13,515 in The Vehicle Production Group LLC (“VPG”), a company that is developing a natural gas vehicle made in the United States for taxi and paratransit use. The Company accounts for its investment in VPG under the cost method of accounting as the Company does not have the ability to exercise significant influence over VPG’s operations.

On February 25, 2011 (the “Closing Date”), the Company paid $1,200 for a 19.9% interest in ServoTech Engineering, Inc. (“ServoTech”), a company that provides design and engineering services for natural gas fueling systems among other services. The Company also has an option to purchase the remaining 80.1% of ServoTech for $2,800 over the 15 month period following the Closing Date (the “Purchase Option”). On April 30, 2012, the Company exercised the Purchase Option, paid $1,400 in cash on that date and agreed to pay an additional $1,400 in cash on October 31, 2012. Through March 31, 2012, the Company accounted for its interest using the equity method of accounting as the Company had the ability to exercise significant influence over ServoTech’s operations. Beginning April 1, 2012, the Company will consolidate the financial results of ServoTech into its financial results.

Note 11—Accrued Liabilities

Accrued liabilities at December 31, 2011 and March 31, 2012 consisted of the following:

Note 12—Warranty Liability

The Company records warranty liabilities at the time of sale for the estimated costs that may be incurred under its standard warranty. Changes in the warranty liability are presented in the following tables:

Note 13—Long-term Debt

In conjunction with the Company’s acquisition of its 70% interest in Dallas Clean Energy, LLC (“DCE”), on August 15, 2008, the Company entered into a credit agreement (“Credit Agreement”) with PlainsCapital Bank (“PCB”). The Company borrowed $18,000 (the “Facility A Loan”) to finance the acquisition of its membership interests in DCE. The Company also obtained a $12,000 line of credit from PCB to finance capital improvements of the DCE processing facility and to pay certain costs and expenses related to the acquisition and the PCB loans (the “Facility B Loan”).

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On October 7, 2009, the Facility A Loan was repaid in full and converted into a $20,000 line of credit (the “A Line of Credit”) pursuant to an amendment to the Credit Agreement. On August 13, 2010, the Credit Agreement was amended to extend the maturity date of the A Line of Credit to August 14, 2011 and add an unused facility fee. The amendment also provided for a 1-year option to extend the maturity date to August 14, 2012, subject to the Company not being in default on the A Line of Credit. The unused facility fees are to be paid quarterly, in an amount equal to one-tenth of one percent (0.10%) of the unused portion. The Company elected not to renew the A Line of Credit on August 14, 2011 and the Line of Credit expired on that date. The principal amount of the Facility B Loan became due and payable in annual payments commencing on August 1, 2009, and continuing each anniversary date thereafter, with each such payment being in an amount equal to the lesser of twenty percent of the aggregate principal amount of the Facility B Loan then outstanding or $2,800. Pursuant to an amendment to the Facility B loan between the Company and PCB dated November 1, 2010, PCB agreed to forgo the scheduled payment due from the Company on August 2010 in the amount of $2,059 until January 31, 2011, which payment was made on such date. On March 31, 2011, the Company paid in full the remaining principal and interest that was due under the Facility B Loan.

In conjunction with the DCE acquisition mentioned above, the Company also entered into a Loan Agreement with DCE (the “DCE Loan”) to provide secured financing of up to $14,000 to DCE for future capital expenditures or other uses as agreed to by the Company, in its sole discretion. On March 31, 2011, the entire amount of unpaid principal and interest due under the DCE Loan was paid to the Company. The interest income related to the DCE Loan has been eliminated in the accompanying consolidated statements of operations.

Revenue Bonds

On March 25, 2011, the Company’s 70% owned subsidiary, Dallas Clean Energy McCommas Bluff, LLC, a Delaware limited liability company (“DCEMB”), arranged for a $40,200 tax-exempt bond issuance (the “Revenue Bonds”). The Revenue Bonds will be repaid from the revenue generated by DCEMB from the sale of RNG. The Revenue Bonds are secured by the revenue and assets of DCEMB and are non-recourse to DCEMB’s direct and indirect parent companies, including the Company. The bond repayments are amortized through December 2024 and the average coupon interest rate on the bonds is 6.60%. The bond issuance closed March 31, 2011.

The bond proceeds will primarily be used to finance further improvements and expansion of the landfill gas processing facility owned by DCEMB at the McCommas Bluff landfill outside of Dallas, Texas. A portion of the proceeds were used to retire the DCE Loan discussed above. The Company, in turn, used the proceeds from the payoff of the DCE Loan to repay approximately $8,000 owed by the Company to PCB under the Facility B Loan on March 31, 2011.

Pursuant to the Loan Agreement, dated as of January 1, 2011 (the “Loan Agreement”), between DCEMB and the Mission Economic Development Corporation (the “Issuer”), DCEMB has covenanted with the Issuer to make loan repayments equal to the principal and interest coming due on the Revenue Bonds. DCEMB executed a promissory note, dated March 31, 2011 (the “Note”), as evidence of its obligations under the Loan Agreement. Pursuant to the Trust Indenture, dated as of January 1, 2011 (the “Indenture”), the Issuer has pledged and assigned to the Trustee (as defined below) all of the Issuer’s right, title and interest in and to the Loan Agreement (with certain specified exceptions) and the Note.

The obligations of DCEMB under the Loan Agreement are secured by a Leasehold Deed of Trust, Assignment of Rents, Security Agreement and Fixture Filing, dated as of January 1, 2011 (the “Deed of Trust”), executed by DCEMB in favor of the deed of trust trustee named therein for the benefit of the Bank of New York Mellon Trust Company, N.A., as Trustee (the “Trustee”). In addition, DCEMB executed a Security Agreement (the “Security Agreement”), as security for its obligations, pursuant to which DCEMB granted to the Trustee a security interest in all right, title and interest of DCEMB to the Collateral (as defined in the Security Agreement), which includes, but is not limited to, DCEMB’s rights, title and interest in any gas sale agreements, including the gas sale agreement with Shell Energy North America (US), L.P. (the “Shell Gas Sale Agreement”), and the funds and accounts held under the Indenture.

Pursuant to a Consent and Agreement, by and between Shell Energy, The Bank of New York Mellon Trust Company, N.A., as Depository Bank (the “Depository Bank”), DCEMB and the Trustee, dated as of January 1, 2011 (the “Consent Agreement”), Shell Energy agreed to make all payments due to DCEMB under the Shell Gas Sale Agreement to the Depository Bank. In addition, other revenues generated through the sale of gas produced at the facility will be paid directly to the Depository Bank pursuant to a Depository and Control Agreement, dated as of January 1, 2011 (the “Depository Agreement”), among DCEMB, the Trustee and the Depository Bank.

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All payments received by the Depository Bank will be placed into various accounts in accordance with the requirements of the Indenture and the Depository Agreement. The funds in these accounts will be used to service required debt payments, finance further improvements and expansion of the landfill gas processing facility owned by DCEMB, finance the operations and maintenance of DCEMB, finance certain expenses associated with setting up and maintaining the accounts, and other uses as prescribed in the Depository Agreement. The Depository Bank will make payments out of these accounts in accordance with the requirements of the Depository Agreement. At the end of each month after all required account fundings have been fulfilled in accordance with the Depository Agreement, all remaining excess funds will be placed into a Surplus Account. The funds in the Surplus Account will be delivered to DCEMB so long as (i) DCEMB’s Debt Service Coverage Ratio (as defined) for the most recent four calendar quarters then ended equals or exceeds 1.25:1, (ii) DCEMB’s Debt Service Coverage Ratio (as defined) is reasonably projected to equal or exceed 1.25:1 for the next four calendar quarters, (iii) no events of default have occurred as defined by the Indenture and the Loan Agreement, and (iv) after giving effect to the transfer, DCEMB’s Minimum Days Cash on Hand (as defined) shall be, or shall at any time be projected to be, more than the lesser of thirty-five Days Cash on Hand (as defined) or $1,300. Due to these restrictions on this cash, the Company has classified all of this cash as restricted cash on the balance sheet. The Company records the restricted cash that is expected to be received and used within the next 12 months from the Depository Bank for working capital and operating purposes as current in its balance sheet, and presents the remaining balance as non-current in the line item notes receivable and other long term assets. At March 31, 2012, $9,530 was recorded as long term restricted cash and $5,626 was recorded as short term restricted cash in the accompanying consolidated balance sheet.

Pursuant to a Collateral Assignment and Consent Agreement with Atmos Pipeline—Texas (“Atmos”), DCEMB has collaterally assigned to the Trustee, subject to certain reserved rights and the consent of Atmos, the transportation agreements of the Company with Atmos.

The Indenture and the Loan Agreement have certain non-financial debt covenants with which DCEMB must comply. As of March 31, 2012, DCEMB was in compliance with all its debt covenants under the Indenture and the Loan Agreement.

Purchase Notes

In connection with the closing of the Company’s acquisition of IMW, the Company agreed to make future payments consisting of four annual payments in the amount of $12,500. Each payment under the IMW Notes will consist of $5,000 in cash and $7,500 in cash and/or shares of the Company’s common stock (the exact combination of cash and/or stock to be determined at the Company’s option). In addition, pursuant to a security agreement executed at closing, the IMW Notes are secured by a subordinate security interest in IMW.

In connection with the closing of the Company’s acquisition of Northstar, the Company agreed to make future payments consisting of five annual payments in the amount of $700 each with the first payment due December 15, 2011.

In connection with the closing of the Company’s acquisition of Weaver Electric, Inc. on October 3, 2011, the Company paid $1,000 in cash and agreed to make four additional annual payments in the amount of $250 each with the first payment due October 3, 2012 (the “Weaver Notes”).

The difference between the carrying amount and the face amount of these obligations is being accreted to interest expense over the remaining term of the obligations.

HSBC Lines of Credit

Also in connection with the closing of the Company’s acquisition of IMW, the Company entered into an Assumption Agreement (the “Assumption Agreement”) with HSBC Bank Canada (“HSBC”) pursuant to which the Company assumed the obligations and liabilities of IMW under the following arrangements with HSBC (collectively, the “IMW Lines of Credit”):

(i)                                     An operating line of credit with a limit of $10,000 in Canadian dollars (“CAD”) bearing interest at prime plus 1.25%, to assist in financing the day-to-day working capital needs of IMW.

(ii)                                  A bank guarantee line with a limit of CAD$3,000, which allows IMW to provide guarantees and/or standby letters of credit to overseas suppliers or bid/performance deposits on contracts.

(iii)                               A forward exchange contract line with a limit of CAD$13,750. The forward exchange contract line allows IMW to enter into foreign exchange forward contracts up to the notional limit of CAD$13,750 (no forward exchange contracts were outstanding at March 31, 2012).

(iv)                              A MasterCard limit with a maximum amount of CAD$150.

(v)                                 An operating line of credit with a limit of 5,000 Renminbi (“RMB”) (CAD$791) bearing interest at the 6 month People’s Bank of China rate plus 2.5% and a sub-limit bank guarantee line of 5,000 RMB. The aggregate of the balances in the lines cannot exceed 5,000 RMB.

(vi)                              A 16,750 Bengali Taka (CAD$197) operating line of credit bearing interest at 14%.

(vii)                           A 170,000 Columbian Peso (CAD$94) operating line of credit bearing interest at the Colombia benchmark rate plus 7 to 12%.

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The IMW Lines of Credit are secured by a general security agreement providing a first priority security interest in all present and after acquired personal property of IMW, including specific charges on all serial numbered goods, inventory and other assets and assignment of risk insurance (the “Security”). The IMW Lines of Credit contain no fixed repayment terms or mandatory principal payments and are due on demand. Based on the relevant accounting guidance, the Company has classified this debt pursuant to the credit agreement as short-term given that it is due on demand.

The Assumption Agreement with HSBC also includes certain financial covenants. Among these financial covenants are that IMW shall not permit: 1) its ratio of debt to tangible net worth to be greater than 3.75 to 1.0 from January 1, 2012 through March 31, 2012, and greater than 3.5 to 1.0 from April 1, 2012 through June 30, 2012, and greater than 3.0 to 1.0 on or after July 1, 2012, 2) its tangible net worth at anytime be below CAD$7,000 and 3) its ratio of current assets to current liabilities to be less than 1.15 to 1.0 until March 31, 2012 and less than 1.25 to 1.0 on or after April 1, 2012. IMW was in compliance with the financial covenants as of March 31, 2012.

In addition, the Company and IMW agreed that should the making of any scheduled payment by IMW to the seller of IMW under the IMW Notes result in IMW being in breach of the Assumption Agreement, the IMW Lines of Credit or the Security, the Company shall furnish IMW with the funds needed to remain in compliance with the Assumption Agreement, the IMW Lines of Credit and the Security. Further, the Company and IMW agreed that should IMW make any future earn-out payments to the seller of IMW in connection with the acquisition of IMW, and should the making of such earn-out payments result in IMW being in breach of the Assumption Agreement, the IMW Lines of Credit or the Security, then the Company shall furnish IMW with the funds needed to make such earn-out payments and remain in compliance with the Assumption Agreement, the IMW Lines of Credit and the Security.

Chesapeake 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 million of debt securities for the development, construction and operation of liquefied natural gas stations (the “CHK Financing”) pursuant to the issuance of three convertible promissory notes, each having a principal amount of $50 million (each a “CHK Note” and collectively the “CHK Notes”). Chesapeake Energy Corporation guaranteed Chesapeake’s commitment to purchase the CHK Notes under the CHK Agreement.

The first CHK Note was issued on July 11, 2011, and the Company expects to issue the second and third CHK Notes on June 29, 2012 and June 28, 2013, respectively. The CHK Notes bear interest at the rate of 7.5% per annum (payable quarterly, in arrears, on March 31, June 30, September 30 and December 31 of each year) and are convertible at Chesapeake’s option into shares of the Company’s common stock at a conversion price of $15.80 per share (the “CHK Conversion Price”). Subject to certain restrictions, the Company can force conversion of each CHK Note into shares of the Company’s common stock if, following the second anniversary of the issuance of a CHK Note, the Company’s shares of common stock trade at a 40% premium to the CHK Conversion Price for at least twenty trading days in any consecutive thirty trading day period. The entire principal balance of each CHK Note is due and payable seven years following its issuance, and the Company may repay each CHK Note in shares of the Company’s common stock or cash. The CHK Agreement restricts the use of the CHK Financing proceeds to financing the development, construction and operation of liquefied natural gas stations and payment of certain related expenses. At March 31, 2012, approximately $32,000 of these funds were included in long term restricted cash as the Company anticipates primarily using the funds to build LNG fueling stations. The CHK Agreement also provides for customary events of default which, if any of them occurs, would permit or require the principal of, and accrued interest on, the CHK Notes to become, or to be declared, due and payable.

In connection with the CHK Financing, the Company also entered into a Registration Rights Agreement, dated July 11, 2011, with Chesapeake (the “CHK Registration Rights Agreement”) pursuant to which the Company agreed, subject to the terms and conditions of the CHK Registration Rights Agreement, to (i) file with the Securities and Exchange Commission one or more registration statements relating to the resale of the Company’s common stock issuable upon conversion of the CHK Notes, and (ii) at the request of Chesapeake, to participate in one or more underwritten offerings of the Company’s common stock issuable upon conversion of the CHK Notes. If the Company does not meet certain of its obligations under the CHK Registration Rights Agreement with respect to the registration of the Company’s common stock, it will be required to pay monthly liquidated damages of 0.75% of the principal amount of the CHK Note represented by the Company’s common stock included (or to be included, as the case may be) in the applicable registration statement until the related obligation is met. As of March 31, 2012, the Company met its obligations under the CHK Registration Rights Agreement.

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SLG Notes

On August 24, 2011, the Company entered into Convertible Note Purchase Agreements (each, an “SLG Agreement” and collectively the “SLG Agreements”) with each of Springleaf Investments Pte. Ltd., a wholly-owned subsidiary of Temasek Holdings Pte. Ltd., Lionfish Investments Pte. Ltd., an investment vehicle managed by Seatown Holdings International Pte. Ltd., and Greenwich Asset Holding Ltd., a wholly-owned subsidiary of RRJ Capital Master Fund I, L.P. (each, a “Purchaser” and collectively, the “Purchasers”), whereby the Purchasers agreed to purchase from the Company $150 million of 7.5% convertible notes due 2016 (each a “SLG Note” and collectively the “SLG Notes”). The transaction closed and the SLG Notes were issued on August 30, 2011.

The SLG Notes bear interest at the rate of 7.5% per annum (payable quarterly, in arrears, on March 31, June 30, September 30 and December 31 of each year) and are convertible at each Purchaser’s option into shares of the Company’s common stock at a conversion price of $15.00 per share (the “SLG Conversion Price”). Subject to certain restrictions, the Company can force conversion of each SLG Note into shares of the Company’s common stock if, following the second anniversary of the issuance of the SLG Notes, the Company’s shares of common stock trade at a 40% premium to the SLG Conversion Price for at least 20 trading days in any consecutive 30 trading day period. The entire principal balance of each SLG Note is due and payable five years following its issuance, and the Company may repay the principal balance of each SLG Note in shares of the Company’s common stock or cash. The SLG Agreements also provide for customary events of default which, if any of them occurs, would permit or require the principal of, and accrued interest on, the SLG Notes to become, or to be declared, due and payable.

In connection with the SLG Agreements, the Company also entered into a Registration Rights Agreement, dated August 24, 2011, with each of the Purchasers (the “SLG Registration Rights Agreements”) pursuant to which the Company agreed, subject to the terms and conditions of the SLG Registration Rights Agreements, to (i) file with the Securities and Exchange Commission one or more registration statements relating to the resale of the Company’s common stock issuable upon conversion of the SLG Notes, and (ii) at the request of the Purchasers, participate in one or more underwritten offerings of the Company’s common stock issuable upon conversion of the SLG Notes. If the Company does not meet certain of its obligations under the SLG Registration Rights Agreements with respect to the registration of the Company’s common stock, it will be required to pay monthly liquidated damages of 0.75% of the principal amount of the SLG Note represented by the Company’s common stock included (or to be included, as the case may be) in the applicable registration statement until the related obligation is met, not to exceed 4% of the aggregate principal amount of the SLG Notes per annum. As of March 31, 2012, the Company met its obligations under the SLG Registration Rights Agreement.

Long-term debt at December 31, 2011 and March 31, 2012 consisted of the following:

Note 14—Earnings Per Share

Basic earnings per share is based upon the weighted-average number of shares outstanding during each period. Diluted earnings per share reflects the impact of assumed exercise of dilutive stock options and warrants. The information required to compute basic and diluted earnings per share is as follows:

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Certain securities were excluded from the diluted earnings per share calculations for the three months ended March 31, 2011 and 2012, respectively, as the inclusion of the securities would be anti-dilutive to the calculation. The amounts outstanding as of March 31, 2011 and 2012 for these instruments are as follows:

Note 15—Stock-Based Compensation

The following table summarizes the compensation expense and related income tax benefit related to the stock-based compensation expense recognized during the periods:

Stock Options

The following table summarizes the Company’s stock option activity during the three months ended March 31, 2012:

As of March 31, 2012, there was $23,607 of total unrecognized compensation cost related to non-vested shares. That cost is expected to be recognized over a weighted average period of 1.4 years. The total fair value of shares vested during the three months ended March 31, 2012 was $3,080.

The Company plans to issue new shares to its employees upon the employee’s exercise of their options. The intrinsic value of all options exercised during the three months ended March 31, 2011 and 2012 was $541 and $12,955, respectively.

The fair value of each option is estimated on the date of grant using the Black-Scholes option pricing model with the following assumptions used for grants in 2012:

The weighted-average grant date fair values of options granted during the three months ended March 31, 2011 and 2012 were $9.11, and $9.09, respectively. The volatility amounts used during the period were estimated based on a certain peer group of the Company’s historical volatility for a period commensurate with the expected life of the options granted, the Company’s historical

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volatility, and the Company’s implied volatility of its traded options. The expected lives used during the periods were based on historical exercise periods and the Company’s anticipated exercise periods for its outstanding options. The risk free rates used during the year were based on the U.S. Treasury yield curve for the expected life of the options at the time of grant. The Company recorded $3,377 and $3,342 of stock option expense during the three months ended March 31, 2011 and 2012, respectively. The Company has not recorded any tax benefit related to its stock option expense.

Restricted Stock Units

The Company issued restricted stock units (“RSUs”) to certain key employees during the three months ended March 31, 2012.  A holder of RSUs will receive one share of the Company’s common stock for each RSU he holds if (x) between January 25, 2014 and January 24, 2016 the closing price of the Company’s common stock equals or exceeds, for twenty consecutive trading days, 135% of the closing price of the Company’s common stock on the RSU grant date (the closing price on the RSU grant date, January 25, 2012, was $15.11) (the “Stock Price Condition”) and (y) the holder is employed by the Company at the time the Stock Price Condition is satisfied. If the Stock Price Condition is not satisfied prior to January 24, 2016, the RSUs will be automatically forfeited. The RSUs are subject to the terms and conditions of the Company’s Amended and Restated 2006 Equity Incentive Plan and a Notice of Grant of Restricted Stock Unit and Restricted Stock Unit Agreement.

The fair value of the RSUs was estimated using a binomial lattice model that incorporates a Monte Carlo Simulation (the “Monte Carlo Method”).

The following table summarizes the Company’s RSU activity during the three months ended March 31, 2012:

As of March 31, 2012, there was $14,722 of total unrecognized compensation cost related to non-vested units. That cost is expected to be recognized over a weighted average period of 1.8 years.

The fair value of each RSU was estimated on the date of grant using the Monte Carlo Method with the following assumptions:

The volatility amounts used during the period were estimated based on the Company’s historical volatility for a period commensurate with the term of the RSUs granted and the Company’s implied volatility of its traded options. The expected life of the RSUs was derived using the Monte Carlo Method. The risk free rates used during the year were based on the United States Treasury yield curve for the expected term of the RSUs at the date of grant. The Company recorded $1,338 of expense and has not recorded any tax benefit related to the expense of the RSUs during the three months ended March 31, 2012.

Note 16—Environmental Matters, Litigation, Claims, Commitments and Contingencies

The Company is subject to federal, state, local, and foreign environmental laws and regulations. The Company does not anticipate any expenditures to comply with such laws and regulations which would have a material impact on the Company’s consolidated financial position, results of operations, or liquidity. The Company believes that its operations comply, in all material respects, with applicable federal, state, local and foreign environmental laws and regulations.

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The Company may become party to various legal actions that arise in the ordinary course of its business. During the course of its operations, the Company is also subject to audit by tax authorities for varying periods in various federal, state, local and foreign tax jurisdictions. Disputes may arise during the course of such audits as to facts and matters of law. It is impossible at this time to determine the ultimate liabilities that the Company may incur resulting from any lawsuits, claims and proceedings, audits, commitments, contingencies and related matters or the timing of these liabilities, if any. If these matters were to be ultimately resolved unfavorably, an outcome not currently anticipated, it is possible that such outcome could have a material adverse effect upon the Company’s consolidated financial position or results of operations. However, the Company believes that the ultimate resolution of such actions will not have a material adverse affect on the Company’s consolidated financial position, results of operations, or liquidity.

On July 15, 2010, the Internal Revenue Service (“IRS”) sent the Company a letter disallowing approximately $5,073 related to certain claims it made from October 1, 2006 to June 30, 2008 under the Volumetric Excise Tax Credit (“VETC”) program. The Company believes its claims were properly made and has appealed the IRS’s request for payment.

Note 17—Income Taxes

The Company is required to recognize the impact of a tax position in its financial statements if the position meets the more likely than not threshold of being sustained by the taxing authority upon examination, based on the technical merits of the position. The Company accrues interest based on the difference between a tax position recognized in the financial statements and the amount claimed on its returns at statutory interest rates. The net interest incurred was immaterial for the three months ended March 31, 2011 and 2012. Further, the Company accrues penalties if the tax position does not meet the minimum statutory threshold to avoid penalties. No penalties have been accrued by the Company. The Company’s unrecognized tax benefits as of March 31, 2012 are unchanged from December 31, 2011.

The Company is subject to taxation in the United States and various states and foreign jurisdictions. The Company’s tax years for 2007 through 2010 are subject to examination by various tax authorities. The Company is no longer subject to United States examination for years before 2008, and state examinations for years before 2007.  On July 15, 2010, the IRS sent the Company a letter disallowing approximately $5,073 related to certain claims the Company made from October 1, 2006 to June 30, 2008 under the VETC program and is seeking repayment of such amount. The Company believes its claims were properly made and has appealed the IRS’s request for payment.

Note 18—Fair Value Measurements

The Company follows authoritative guidance for fair value measurements with respect to assets and liabilities that are measured at fair value on a recurring basis and nonrecurring 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 is broken down into 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.

During the three months ended March 31, 2012, the Company’s financial instruments consisted of available-for-sale securities, natural gas futures contracts, debt instruments, a contingent consideration obligation, and its Series I warrants. For securities available-for-sale, the fair value is determined by the most recent trading prices available for each security or for comparable securities, and thus represent Level 2 fair value measurements. The Company uses quoted forward price curves, discounted to reflect the time value of money, to value its natural gas futures contracts which are considered to be a Level 2 fair value measurement. The Company uses an income approach, projecting the financial results for the associated entity, discounted to reflect the time value of money, to value its contingent consideration obligation which is considered to be a Level 3 fair value measurement. The fair market value of the Company’s debt instruments approximated their carrying values at March 31, 2011 and 2012. The Company uses the Black-Scholes model to value the Series I warrants. The Company believes the best method to approximate the market participant’s view of the volatility of its Series I warrants is to use the implied volatilities of its short-term (i.e. 3 to 9 month) traded options and extrapolate the data over the remaining term of the Series I warrants, which was approximately 4 years and 1 month as of March 31, 2012. This method has been utilized consistently in the periods presented. Given  the extrapolation beyond the term of the short term exchange traded options is not based on observable market inputs for a significant portion of the remaining term of the warrants, the Series I warrants have been classified as a Level 3 fair value determination in the table below.

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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, 2011 and March 31, 2012, respectively:

(1) Included in Short-term investments in the condensed consolidated balance sheets. See note 5-Investments for further information.

(2) See note 6–Derivative Transactions for further information.

(3) The current portion is included in accrued liabilities, and the long-term portion is included in other long-term liabilities in the condensed consolidated balance sheets.

(4) Included in other long-term liabilities in the condensed consolidated balance sheets.

The following tables provide a reconciliation of the beginning and ending balances of items measured at fair value on a recurring basis in the table above that used significant unobservable inputs (Level 3).

(1) Reported on the face of the condensed consolidated statements of operations.

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Valuation processes for Level 3 Fair Value Measurements

Fair value measurements of liabilities which fall within level 3 of the fair value hierarchy are determined by the Company’s accounting department, who report to the Chief Financial Officer (“CFO”).  The fair value measurements are compared to those of the prior reporting periods to ensure that changes are consistent with expectations of management based upon the sensitivity and nature of the inputs.

Sensitivity of Level 3 measurements to changes in significant unobservable inputs

Contingent Consideration

Pursuant to the terms presented in the Asset Purchase Agreement, the IMW shareholder will earn additional consideration if IMW achieves certain minimum gross profit targets in fiscal years 2011 through 2014.  Therefore, the Company estimated the fair value of the contingent consideration using a discounted cash flow model that considers the payout structure based on gross profit targets, the probabilities of reaching the thresholds in each year, and the risk-adjusted discount rate.  Significant changes in any of those inputs in isolation would result in a significant change in the fair value measurement.  Generally, a positive change in the assumption used for the probability of achieving a higher gross profit target threshold would result in a directionally similar change in the estimated fair value of the contingent consideration.  Conversely, an increase in the assumed discount rate would have a directionally opposite impact on the estimated fair value measurement of the contingent consideration. 

Series I Warrant liability

The inputs to estimate the fair value of the Company’s Series I Warrant Liability are the current market price of the Company’s common stock, the exercise price of the warrant, its remaining term, the volatility of the Company’s common stock market price, and an assumed discount rate.  Significant changes in any of those inputs in the isolation can result in a significant change in the fair value measurement.  Generally, a positive change in the market price of the Company’s common stock, and an increase in the volatility of the Company’s commons stock, or an increase in the remaining term of the warrant would result in a directionally similar change in the estimated fair value of the Company’s Series I Warrants and thus an increase in the associated liability.  An increase in the assumed discount rate or a decrease in the positive differential between the warrant’s exercise price and the market price of the Company’s common stock would result in a decrease in the estimated fair value measurement of the Series I Warrants and thus a decrease in the associated liability.  The Company has not, nor plans to, declare dividends on its common stock, and thus, there is no directionally similar change in the estimated fair value of the warrants due to the dividend assumption.

Non-financial assets

No impairments of long-lived assets measured at fair value on a non-recurring basis have been incurred during the three months ended March 31, 2011 and March 31, 2012.  The Company’s use of these nonfinancial assets does not differ from their highest and best use, as determined from the perspective of a market participant.

Note 19—Recently Adopted Accounting Changes and Recently Issued Accounting Standards

On January 1, 2012, the Company adopted changes issued by the FASB to conform existing guidance regarding fair value measurement and disclosure between GAAP and International Financial Reporting Standards. These changes both clarify the FASB’s intent about the application of existing fair value measurement and disclosure requirements and amend certain principles or requirements for measuring fair value or for disclosing information about fair value measurements. The clarifying changes relate to the application of the highest and best use and valuation premise concepts, measuring the fair value of an instrument classified in a reporting entity’s shareholders’ equity, and disclosure of quantitative information about unobservable inputs used for Level 3 fair value measurements. The amendments relate to measuring the fair value of financial instruments that are managed within a portfolio, application of premiums and discounts in a fair value measurement, and additional disclosures concerning the valuation processes used and sensitivity of the fair value measurement to changes in unobservable inputs for those items categorized as Level 3, a reporting entity’s use of a nonfinancial asset in a way that differs from the asset’s highest and best use, and the categorization by level in the fair value hierarchy for items required to be measured at fair value for disclosure purposes only. Other than the additional disclosure requirements (see note 18), the adoption of these changes had no impact on the condensed consolidated financial statements.

On January 1, 2012, the Company adopted changes issued by the FASB to the presentation of comprehensive income. These changes give an entity the option to present the total of comprehensive income, the components of net income, and the components of other comprehensive income either in a single continuous statement of comprehensive income or in two separate but consecutive statements. The option to present components of other comprehensive income as part of the statement of changes in stockholders’ equity was eliminated. The items that must be reported in other comprehensive income or when an item of other comprehensive income must be reclassified to net income were not changed. Additionally, no changes were made to the calculation and presentation of earnings per share. Management elected to present the two-statement option. Other than the change in presentation, the adoption of these changes had no impact on the condensed consolidated financial statements.

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Note 20—Volumetric Excise Tax Credit (VETC)

The Company records its VETC credits as revenue in its condensed consolidated statements of operations as the credits are fully refundable and do not need to offset income tax liabilities to be received. VETC revenues for the three month periods ended March 31, 2011 and 2012 were $4,217 and $0, respectively. The VETC legislation expired on December 31, 2011.

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 (this “MD&A”) should be read together with the unaudited condensed consolidated financial statements and the related notes included elsewhere 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, 2011 contained in our 2011 Annual Report on Form 10-K filed with the SEC on March 12, 2012, as well as the consolidated financial statements and notes contained therein.

Cautionary Statement Regarding Forward Looking Statements

This MD&A and other sections of this report contain forward looking statements. We make forward-looking statements, as defined by the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, and in some cases, you can identify these statements by forward-looking words such as “if,” “shall,” “may,” “might,” “will likely result,” “should,” “expect,” “plan,” “anticipate,” “believe,” “estimate,” “project,” “intend,” “goal,” “objective,” “predict,” “potential” or “continue,” or the negative of these terms and other comparable terminology. These forward-looking statements, which are based on various underlying assumptions and expectations and are subject to risks, uncertainties and other unknown factors, may include projections of our future financial performance based on our growth strategies and anticipated trends in our business. These statements are only predictions based on our current expectations and projections about future events that we believe to be reasonable. There are important factors that could cause our actual results, level of activity, performance or achievements to differ materially from the historical or future results, level of activity, performance or achievements expressed or implied by such forward-looking statements. These factors include, but are not limited to, those discussed under the caption “Risk Factors” in this report and in our 2011 Annual Report on Form 10-K (the“2011 10-K”). In preparing this MD&A, we presume that readers have access to and have read the MD&A in our 2011 Annual Report on Form 10-K pursuant to Instruction 2 to paragraph (b) of Item 303 of Regulation S-K. We undertake no duty to update any of these forward-looking statements after the date of filing of this report to conform such forward-looking statements to actual results or revised expectations, except as otherwise required by law.

We provide natural gas solutions for vehicle fleets primarily in the United States and Canada. Our primary business activity is selling compressed natural gas (“CNG”) and liquefied natural gas (“LNG”) vehicle fuel to our customers. We also manufacture and service advanced natural gas fueling compressors and related equipment, build, operate and maintain fueling stations, sell or lease fueling stations to our customers, process and sell renewable natural gas (“RNG”), and provide natural gas vehicle conversions. Our customers include fleet operators in a variety of markets, such as trucking, airports, taxis, refuse hauling, and public transit. In April 2008, we opened our first CNG station in Lima, Peru, through our joint venture, Clean Energy del Peru. In August 2008, we acquired 70% of the outstanding membership interests of Dallas Clean Energy LLC (“DCE”). DCE owns a facility that collects, processes and sells RNG at the McCommas Bluff landfill in Dallas, Texas. On October 1, 2009, we completed our acquisition of BAF Technologies, Inc. (“BAF”), a company that provides natural gas conversions, alternative fuel systems, application engineering, service and warranty support and research and development for natural gas vehicles. On September 7, 2010, we completed the purchase of I.M.W. Industries Ltd. (“IMW”), a company that manufactures and services advanced, non-lubricated natural gas fueling compressors and related equipment. On December 15, 2010, we acquired Wyoming Northstar Incorporated, Southstar LLC, and M&S Rental, LLC (collectively “Northstar”), a provider of design, engineering, construction and maintenance services for LNG and liquefied to compressed natural gas (“LCNG”) fueling stations.

Overview

This overview discusses matters on which our management primarily focuses in evaluating our financial condition and operating performance.

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Sources of revenue.  We generate a majority of our revenue from selling CNG and LNG, and commencing on September 7, 2010, also from selling advanced natural gas fueling compressors and related equipment and maintenance services through our subsidiary, IMW. A significant portion of our revenue is also earned by designing and constructing and selling natural gas fueling stations, selling natural gas vehicle conversions through our wholly owned subsidiary, BAF, providing fueling station operations and maintenance services to our customers, and selling pipeline quality RNG produced by our DCE joint venture. We also generate limited revenue by providing financing for our customers’ natural gas vehicle purchases.

Key operating data.  In evaluating our operating performance, our management focuses primarily on: (1) the amount of CNG and LNG 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 to our customers at stations where we provide operating and maintenance (“O&M”) services, but do not sell the CNG or LNG, plus (iii) our proportionate share of the gasoline gallon equivalents sold as CNG by our joint venture in Peru, plus (iv) our proportionate share of the gasoline gallon equivalents of RNG produced and sold as pipeline quality natural gas by DCE), (2) our gross margin (which we define as revenue minus cost of sales), and (3) net income (loss) attributable to us. The following table, which you should read in conjunction with our condensed consolidated financial statements and notes contained elsewhere in this quarterly report on Form 10-Q and our consolidated financial statements and notes contained in our annual report on Form 10-K for the year ended December 31, 2011, presents our key operating data for the years ended December 31, 2009, 2010, and 2011 and for the three months ended March 31, 2011 and 2012: