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Exhibit 10.27    
    

 
 

OBLIGATION TRANSFER AND SECURITIES PURCHASE AGREEMENT    
    

        THIS OBLIGATION TRANSFER AND SECURITIES PURCHASE AGREEMENT (this
"Agreement") is made and entered into as of December 28, 2006, by and between Clean Energy Fuels Corp., a Delaware corporation
(the "Company"), and Boone Pickens (the "Purchaser"). 

 
 

BACKGROUND    
    

        Upon the terms and conditions of this Agreement, the Company desires to transfer to Purchaser certain hedge contracts that are in a loss position, receive
forgiveness of certain indebtedness to Purchaser that was incurred to fund certain margin deposits on the hedge contracts, and receive a return of margin deposits that it made out of its own cash
balances. As consideration for the foregoing, the Company will issue a warrant to Purchaser to purchase shares of common stock of the Company in substantially the form attached to this Agreement as
Exhibit A (the "Warrant"). The Warrant and the common stock issuable upon exercise thereof are collectively referred to herein as the
"Securities." 

 
 

AGREEMENT    
    

        In consideration of the mutual promises contained herein and other good and valuable consideration, receipt of which is hereby acknowledged, the parties to this
Agreement agree as follows: 

        1.     Assumption
of Obligations and Sale of Warrant and Related Matters. 

                a.    Assumption of Hedge Positions.    Purchaser hereby agrees to acquire and assume all of the
Company's right, title and interest in and to the Hedge Positions (defined below), together with all associated losses, liabilities, and obligations, as of and after the close of business on
December 28, 2006. "Hedge Positions" mean the futures contracts purchased by the Company on August 2, 2006 attached as Exhibit B. 

                b.    Issuance of Warrant.    Purchaser hereby agrees to take, and the Company agrees to issue to
Purchaser, the Warrant as consideration for the assumed obligations and debt relief set forth in Sections 1.a., 1.c and 1.d of this Agreement. The Warrant will be signed and delivered to
Purchaser upon the execution of this Agreement. 

                c.    Cancellation of Indebtedness.    Purchaser hereby forgives all outstanding principal due under the
Revolving Promissory Note dated November 15, 2006 between the Company and the Purchaser (the "Revolving Note"), which instrument will
promptly be marked cancelled and tendered to the Company. Purchaser confirms that the Company has paid all interest owed to Purchaser under the Revolving Note as of December 28, 2006. 

                d.    Treatment of margin deposits with Sempra Energy Trading Corp ("Sempra ") related to the Hedge Positions. The
Company will receive from Purchaser (1) its initial margin deposits related to the Hedge Positions (approximately $9.5 million) plus (2) the excess margin deposits related to the
Hedge Positions that were funded other than by using the Revolving Note (approximately $13.4 million). Purchaser will wire such funds to the Company for its hedge deposits on or before
January 2007. Purchaser will be entitled to all excess margin deposits related to the Hedge Positions that were funded using the Revolving Note. 

                e.    Execution of Documents.    Purchaser and the Company agree promptly to execute and take all
actions necessary to give effect to the above, including, but not limited to those required by Sempra. 

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        2.     Representations
and Warranties of the Company. The Company hereby represents and warrants to the Purchaser that, as of the date of
the Closing: 

                a.    Organization, Good Standing and Qualification.    The Company is a corporation duly incorporated,
validly existing and in good standing under the laws of the State of Delaware and has all requisite corporate power and authority to carry on its business as now conducted and as proposed to be
conducted. The Company is duly qualified to transact business and is in good standing in the State of California and in each other jurisdiction in which the failure to qualify would have a material
adverse effect on its condition (financial or otherwise), properties, assets, liabilities, business, operations or prospects. 

                b.    Authorization.    This Agreement and the Warrant (collectively, the
"Transaction Documents"), the transactions contemplated hereby and thereby, and the stock issuable upon exercise of the Warrant has been duly authorized
by the Board of Directors of the Company. The Transaction Documents, when executed and delivered by the Company, shall constitute valid and legally binding obligations of the Company, enforceable
against the Company in accordance with their respective terms except as limited by applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance, and other laws of general
application affecting enforcement of creditors' rights generally, and as limited by laws relating to the availability of specific performance, injunctive relief, or other equitable remedies. 

        3.     Representations
and Warranties of the Purchaser. The Purchaser hereby represents and warrants to the Company as of the Closing that: 

                a.    Authorization.    The Purchaser has full power and authority to enter into the Transaction
Documents. Each Transaction Document, when executed and delivered by the Purchaser, will constitute a valid and legally binding obligation of the Purchaser, enforceable in accordance with its terms,
except as limited by applicable bankruptcy, insolvency, reorganization, moratorium, fraudulent conveyance, and any other laws of general application affecting enforcement of creditors' rights
generally, and as limited by laws relating to the availability of a specific performance, injunctive relief, or other equitable remedies. 

                b.    Purchase Entirely for Own Account.    This Agreement is made with the Purchaser in reliance upon
the Purchaser's representation to the Company, which by the Purchaser's execution of this Agreement, the Purchaser hereby confirms, that the Securities to be acquired by the Purchaser will be acquired
for investment for the Purchaser's own account, not as a nominee or agent, and not with a view to the
resale or distribution of any part thereof, and that the Purchaser has no present intention of selling, granting any participation in, or otherwise distributing the same. By executing this Agreement,
the Purchaser further represents that the Purchaser does not presently have any contract, undertaking, agreement or arrangement with any person to sell, transfer or grant participations to such person
or to any third person, with respect to any of the Securities. 

                c.    Knowledge.    The Purchaser is aware of the Company's business affairs and financial condition,
has had the opportunity to ask questions and receive answers regarding this investment in the Company, and has acquired sufficient information about the Company to reach an informed and knowledgeable
decision to acquire the Securities. 

                d.    Restricted Securities.    The Purchaser understands that the Securities have not been, and will
not be, registered under the Securities Act, by reason of a specific exemption from the registration provisions of the Securities Act of 1933 (the "Securities Act") which depends upon, among
other things, the bona fide nature of the investment intent and the accuracy of the Purchaser's representations as expressed herein. The Purchaser understands that the Securities are
"restricted securities" under applicable U.S. federal and state securities laws and that, pursuant to these laws, the Purchaser must hold the Securities indefinitely unless they are registered
with the Securities and 

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Exchange
Commission and qualified by state authorities, or an exemption from such registration and qualification requirements is available. Notwithstanding the foregoing, Purchaser shall have all
rights to registration of the shares of common stock of the Company which are issued upon exercise of the Warrant as otherwise granted to Purchaser pursuant to the Registration Rights Agreement dated
as of December 31, 2002, by and between ENRG, Inc., a Delaware corporation, and the equity security holders, including Purchaser, identified on Schedule A
to such agreement. 

                e.    No Public Market.    The Purchaser understands that no public market now exists for any of the
securities issued by the Company, and that the Company has made no assurances that a public market will ever exist for the Securities. 

                f.    Accredited Investor.    The Purchaser is an accredited investor as defined in Rule 501(a)
of Regulation D promulgated under the Securities Act. The Purchaser warrants that: (1) by reason of the Purchaser's business or financial experience, the Purchaser has the capacity to
protect his interests in connection with the purchase of the Securities and/or (2) the Purchaser has a preexisting personal or business relationship with an officer, director or stockholder of
the Company of a nature and duration as would allow the Purchaser to be aware of the character, business acumen, general business and financial status of the Company. 

        4.     Miscellaneous.

                a.    Successors and Assigns.    The terms and conditions of this Agreement shall inure to the benefit
of and be binding upon the respective successors and assigns of the parties. Nothing in this Agreement, express or implied, is intended to confer upon any party other than the parties hereto or their
respective successors and assigns any rights, remedies, obligations, or liabilities under or by reason of this Agreement, except as expressly provided in this Agreement. 

                b.    Governing Law.    This Agreement and all acts and transactions pursuant hereto and the rights and
obligations of the parties hereto shall be governed, construed and interpreted in accordance with the laws of the State of Delaware without giving effect to principles of conflicts of law. 

                c.    Counterparts.    This Agreement may be executed in two or more counterparts, each of which shall
be deemed an original and all of which together shall constitute one instrument. 

                d.    Titles and Subtitles.    The titles and subtitles used in this Agreement are used for convenience
only and are not to be considered in construing or interpreting this Agreement. 

                e.    Notices.    Any notice required or permitted by this Agreement shall be in writing and shall be
deemed sufficient upon receipt, when delivered personally or by courier, overnight delivery service or confirmed facsimile, or 72 hours after being deposited in the U.S. mail as
certified or registered mail with postage prepaid, if such notice is addressed to the party to be notified at such party's address or facsimile number as set forth below or as subsequently modified by
written notice. 

                f.    Amendments and Waivers.    Any term of this Agreement may be amended or waived only with the
written consent of the Company and the Purchaser. 

                g.    Severability.    If one or more provisions of this Agreement are held to be unenforceable under
applicable law, the parties agree to renegotiate such provision in good faith, in order to maintain the economic position enjoyed by each party as close as possible to that under the provision
rendered unenforceable. In the event that the parties cannot reach a mutually agreeable and enforceable replacement for such provision, then (i) such provision shall be excluded from this
Agreement, (ii) the balance of the Agreement shall be interpreted as if such provision were so excluded and (iii) the balance of the Agreement shall be enforceable in accordance with
its terms. 

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                h.    Entire Agreement.    This Agreement, and the documents referred to herein constitute the entire
agreement between the parties hereto pertaining to the subject matter hereof, and any and all other written or oral agreements existing between the parties hereto are expressly canceled. 

                i.    Corporate Securities Law.    THE SALE OF THE SECURITIES WHICH ARE THE SUBJECT OF THIS AGREEMENT
HAS NOT BEEN QUALIFIED WITH THE COMMISSIONER OF CORPORATIONS OF THE STATE OF CALIFORNIA AND THE ISSUANCE OF THE SECURITIES OR THE PAYMENT OR RECEIPT OF ANY PART OF THE CONSIDERATION THEREFOR PRIOR TO
THE QUALIFICATION IS UNLAWFUL, UNLESS THE SALE OF SECURITIES IS EXEMPT FROM THE QUALIFICATION BY SECTION 25100, 25102 OR 25105 OF THE CALIFORNIA CORPORATIONS CODE. THE RIGHTS OF
ALL PARTIES TO THIS AGREEMENT ARE EXPRESSLY CONDITIONED UPON THE QUALIFICATION BEING OBTAINED UNLESS THE SALE IS SO EXEMPT. 

[Signature
Page Follows] 

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        The
parties have executed this Agreement as of the date first written above. 

	
 	
 	
COMPANY:
	
 	
 	
CLEAN ENERGY
	
 	
 	

By:	

/s/ Rick Wheeler

	 	 	Name: Rick Wheeler

Title: Chief Financial Officer
	
 	
 	

3020 Old Ranch Parkway, Suite 200

Seal Beach, California 90470

Facsimile: (562) 493-4532
	
 	
 	
PURCHASER
	
 	
 	

By:	

/s/ Boone Pickens
 Boone Pickens
	
 	
 	

c/o BP Capital

260 Preston Commons West

8117 Preston Way

Dallas, Texas 75255

Telephone: (214) 265-4165

Facsimile: (214) 750-9773

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EXHIBIT A    
    

Form
of Warrant to Purchase Common Stock 

(See Behind) 

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EXHIBIT B    
    

Hedge
Position Contracts 

	PURCHASE

DATE
 
	 	DESCRIPTION
 
	 	QUANTITY
 
	 	CONTRACT

NUMBER
 

	8/2/2006	 	BOT CAL 08 NG	 	2,000	 	49933340
	8/2/2006	 	BOT CAL 09 NG	 	2,500	 	49933430
	8/2/2006	 	BOT CAL 10 NG	 	2,500	 	49933650
	8/2/2006	 	BOT CAL 11 NG	 	2,500	 	49933790

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Exhibit 10.27

OBLIGATION TRANSFER AND SECURITIES PURCHASE AGREEMENT

BACKGROUND

AGREEMENT

EXHIBIT A

EXHIBIT BQuickLinks
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EXHIBIT 10.28    
    

 
  REVOLVING PROMISSORY NOTE    
    

	 
	 	 
	 	 

	$100,000,000	 	Dallas, Texas	 	November 15, 2006

        FOR
VALUE RECEIVED, CLEAN ENERGY FUELS CORP., a Delaware corporation ("Maker"), promises to pay to the order of the  BOONE PICKENS, an individual residing in
Dallas County, Texas ("Payee"), by payment in immediately available funds and or in lawful money of the United
States of America, the principal sum of ONE HUNDRED MILLION AND NO/100 DOLLARS ($100,000,000.00)or, if greater or less, the aggregate unpaid principal
amount of advances made under this note by Payee to Maker, together with interest on the unpaid principal balance of this note from time to time outstanding until maturity at the lesser of
(i) the Stated Rate (as hereinafter defined) and (ii) the Highest Lawful Rate (as hereinafter defined), provided, that for the full term of this note the interest rate produced by the
aggregate of all sums paid or agreed to be paid to the holder of this note for the use, forbearance or detention of the debt evidenced hereby shall not exceed the Highest Lawful Rate (as hereinafter
defined). 

        1.    Definitions.    As used in this note, the following terms shall
have the respective meaning indicated: 

        (a)   "Business Day" means a day when banks are open for business in Dallas, Texas. 

        (b)   "Chapter One" means Chapter One of Title 79 Texas Revised Civil Statutes, 1925, as amended. 

        (c)   "Contracts" means those futures contracts described on Schedule 1 attached hereto entered into by Maker and Sempra
Energy Trading Corp. as counterparty. 

        (d)   "Debt" means the indebtedness evidenced by this note and the indebtedness to the Payee incurred under or evidenced by the
Loan Documents (as hereinafter defined). 

        (e)   "Highest Lawful Rate" means the maximum non-usurious rate of interest permitted on the execution date hereof
by whichever of applicable federal or Texas laws permit the higher maximum non-usurious interest rate. If Chapter One establishes the Highest Lawful Rate, the Highest Lawful Rate shall be
the "indicated rate ceiling" (as defined in Chapter One). 

        (f)    "Loan Documents" means any and all documents and instruments now or hereafter evidencing, securing or guaranteeing all or
any part of the indebtedness evidenced by this note. 

        (g)   "Maturity Date" means the earlier to occur of (i) the expiration or termination of all of the Contracts or
(ii) November 30, 2011, as the same may hereafter be accelerated pursuant to the provisions of this note or any of the other Loan Documents. 

        (h)   "Stated Rate" means the "Prime Rate" as announced from time to time by Plains Capital Bank plus one percent (1.0%). If
the Prime Rate referred to above changes after the date hereof, the Base Rate shall be automatically increased or decreased, as the case may be, without notice to Maker from time to time as of the
effective time of each change in such Prime Rate. 

        2.    Purpose of Loan.    Maker has heretofore made initial margin
deposits of $9,500,000 to secure the Contracts (the "Initial Margin"). It is contemplated that advances under this Note shall be made solely for the purpose of satisfying maintenance margin
requirements under the Contracts in excess of the Initial Margin (herein called "Maintenance Margin"); provided, however, that Payee in sole discretion may elect to make advances hereunder to satisfy
Initial Margin requirements under the Contracts so long as the total amount of advances made hereunder does not exceed the face amount of this note. 

        3.    Computation of Interest.    Interest on the amount of each
advance against this note shall be computed on the amount of that advance and from the date it is made. Such interest shall be computed for the actual number of days clasped in the applicable calendar
year in which accrued. 

        4.    Payments of Principal Interest.    

        (a)   Mandatory Prepayments. Upon the expiration or early termination and settlement of any Contract (herein called a "Settled
Contract"), Maker shall apply (i) all Initial Margin amounts, if any, advanced under Paragraph 2 above and (ii) all Maintenance Margin amounts returned to Maker in connection with
any such Settled Contract as a mandatory prepayment against the outstanding principal balance of this note. Any mandatory prepayment from returned margin on a Settled Contract made in or after
December 27, 2007 shall permanently reduce the available credit under this note. To the extent a counterparty to any Contract returns Maintenance Margin to Maker that was originally posted by
Maker with proceeds from any advances hereunder, Maker shall apply the full amount of such returned Maintenance Margin as a mandatory prepayment against the outstanding principal balance of this note. 

        (b)   Payment of Interest. Interest on this note shall be due and payable quarterly as it accrues, on the last day of each
calendar quarter, beginning on December 31, 2006, and continuing regularly thereafter until this note has been paid in full. 

        (c)   Payment Upon Maturity. In addition to any mandatory prepayments made pursuant to paragraph (a) above, the
principal of this note, together with accrued and unpaid interest on the unpaid principal balance of this note, shall be due and payable on the Maturity Date. 

        (d)   If
any payment provided for in this note shall become due on a day other than a Business Day, such payment may be made on the next succeeding Business Day (unless the
result of such extension of time would be to extend the date for suck payment into another calendar month or beyond the Maturity Date, and in either such event such payment shall be made on the
Business Day immediately proceeding the day on which such payment would otherwise have been due), and such extension of time shall in such case be included in the computation of interest on this note. 

        (e)   Maker
may at any time pay the full amount or any part of this note without the payment of any premium or fee. All prepayments hereon shall be applied first to the
outstanding principal balance of this note and then to accrued and unpaid interest on this note. Subject to the terms of this note, Maker may borrow, repay and reborrow hereunder until the Maturity
Date. 

        5.    No Usury Intended; Spreading.    Notwithstanding any provision
to the contrary contained in this note or any of the other Loan Documents, it is expressly provided that in no case or event shall the aggregate of (i) all interest on the unpaid balance of
this note, accrued or paid on or from the date hereof and (ii) the aggregate of any other amounts accrued or paid pursuant to this note or any other Loan Documents, which under applicable laws
are or may be deemed to constitute interest upon the indebtedness evidenced by this note from the date hereof, ever exceed the Highest Lawful Rate. In this connection, it is expressly stipulated and
agreed that it is the intent of the Maker and the Payee to contract in strict compliance with the applicable usury laws of the State of Texas and the United State, whichever from time to time permit
the higher rate of interest. In furtherance thereof, none of the terms of this note or any of the other Loan Documents shall ever be construed to create a contract to pay as consideration for the use,
forbearance or detention of money, becoming liable for payment of the indebtedness evidenced by this note shall never by liable for interest in excess of the Highest Lawful Rate. If, for any reason
whatever, the interest paid or received on this note during its full term produces a rate which exceeds the Highest Lawful Rate, the holder of this note shall refund to the payer or, at the holder's
option, credit against the principal of this note such portion of said interest as shall be necessary to cause the interest paid on this note to produce a rate equal to the Highest Lawful Rate. All
sums paid or agreed to be paid to the holder of this note for the use, forbearance or detention of the indebtedness evidenced hereby shall, to the term of this note until payment in full of the
principal (including the period of any renewal or extension hereof), so that the interest hereon throughout the full term of this note shall not exceed the maximum amount permitted by applicable law.
The provisions of this Section 4 shall control all agreements, whether now or hereafter existing and whether written or oral, between the Maker
and the Payee. 

        6.    Default.    An "Event of Default" shall exist upon the
occurrence of any one or more of the following events: 

        (a)   Maker
shall fail to pay when due any principal of, or interest on, this note and such nonpayment shall remain outstanding for more than five (5) days after Maker
receives written notice thereof from Payee: 

        (b)   Maker
shall (i) execute a general assignment for the benefit of Maker's creditors, or (ii) become the subject, voluntarily or involuntarily, of any
bankruptcy, insolvency or reorganization proceeding, or (iii) admit in writing Maker's inability to pay Maker's debts generally as they become due, or (iv) apply for or consent to the
appointment of a custodian, receiver, trustee, or liquidator of Maker or of all or a substantial part of Maker's assets, or (v) file a voluntary petition seeking protection under any
debtor's relief or other insolvency law now or hereafter existing, or (vi) file an answer admitting the material allegations of, or consenting to, or default in filing an answer to, a petition
filed against Maker in a bankruptcy, reorganization, or other insolvency proceedings, or (vii) institute or voluntarily be or become a party to any other judicial proceedings intended to effect
a discharge of the debts of Maker, in whole or in part, or a postponement of the maturity or the collection thereof, or a suspension of any of the rights or powers of Payee granted in the Loan
Documents; 

        (c)   An
order, judgment, or decree shall be entered by any court of competent jurisdiction appointing a custodian, receiver, trustee, or liquidator of Maker or of all or any
substantial part of Maker's assets; or 

        (d)   The
liens, mortgages or security interests created (or purported to be created) by this note or by any other Loan Documents should become unenforceable. 

        Upon
the occurrence of any Event of Default, the owner or holder hereof may, at its, his or her option, exercise any or all rights, powers and remedies afforded under any of the Loan
Documents, all other instruments evidencing, securing or guaranteeing this note and by law, including the right to declare the unpaid balance of principal and accrued interest on this note at once
mature and payable. 

        7.    No Waiver by the Payee.    No delay or omission of the Payee or
any other holder hereof to exercise any power, right or remedy or shall be construed to be a waiver of the right to exercise any such power, right or remedy. 

        8.    Cost and Attorneys" Fees.    If any holder of this note retains
an attorney in connection with any default or to collect, enforce or defend this note or any of the Loan Documents in any lawsuit or in any probate, reorganization, bankruptcy or other proceeding, or
if Maker sues any holder in connection with this note or any of the Loan Documents and does note prevail, then Maker agrees to pay to each such holder, in addition to principal and interest, all
reasonable costs and expenses incurred by such holder in connection with such default or in trying to collect this note or in any such suit or proceeding, including reasonable attorneys' fees. To the
extent not prohibited by applicable law, the Maker will pay all reasonable costs and expenses and reimburse the Payee for any and all reasonable expenditures of every character incurred or expended
from time to time, regardless of whether or not a default shall have occurred, in connection with the Payee's evaluating, monitoring, administrating, and protecting any collateral ("Collateral") now
or hereafter securing payment of this note, and creating, perfecting and realizing upon the Payee's exercising any of its rights and remedies hereunder or under any of the other Loan Documents or at
law, including., without limitation, all attorneys' fees, legal expenses, court costs, auctioneer fees and other fees incurred in connection with liquidation of any Collateral and all other
professional fees. Any amount to be paid hereunder by the Maker to the Payee shall be a demand obligation owing by the Maker to the Payee and shall bear interest from the date of expenditure until
paid at the applicable Stated Rate. 

        9.    Waivers by the Maker and Others.    Maker and any and all
co-makers, endorsers, guarantors, and sureties severally waive notice (including, but not limited to, notice of intent to accelerate and notice of acceleration, notice of protest and
notice of dishonor), demand, presentment for payment, protest, diligence in collecting and the filing of suit for the purpose of fixing liability and consent that 

the
time of payment hereof may be extended and re-extended from time to time without notice to any of them. Each such person agrees that his, her or its liability on or with respect to
this note shall not be affected by any release of or change in any guaranty or security at any time existing or by any failure to perfect or to maintain perfection of any lien against or security
interest in any such security or that the partial or complete unenforceability of any guaranty or other surety obligation, in each case in whole or in part, with or without notice and before or after
maturity. 

        10.    Governing Law.    This note shall be governed by and construed
in accordance with the laws of the State of Texas and the United States of America from time to time in effect. Dallas County, Texas shall be the proper place of venue for suit heron. Maker and any
and all co-makers, endorsers, guarantors and sureties irrevocably agree that any legal proceeding in respect of this note or any of the other Loan Documents shall be brought in the
district courts of Dallas County, Texas or the United States District Court for the Northern District of Texas. 

        11.    Successor and Assigns.    This note and all the covenants and
agreements contained herein shall be binding upon, and shall inure to the benefit of, the respective legal representatives, heirs, trustees, beneficiaries, successors and assigns of Maker and Payee. 

        12.    Business Loans.    Maker warrants and represents to Payee and
all other holders of this note that all loans evidenced by this note are and will be for business, commercial, investment or other similar purpose and not primarily for personal, family, household or
agricultural use, as such terms are used in Chapter One. Advances under this note shall be made solely for the purpose of satisfying maintenance margin requirements in connection with natural gas
futures contracts to which Maker is a party from time to time. 

        13.    Entire Agreement.    This note an the Loan Documents embody the
entire agreement and understanding between Payee and Maker and other parties with respect to the loans to be evidenced by this note and supersede all prior conflicting or inconsistent agreements,
consents and understandings relating to such subject matter. Maker acknowledges and agrees that there are no oral agreements between Maker and Payee which have not been incorporated in this note and
the Loan Documents. 

        14.    Renewal of Prior Note.    This note is executed in renewal of,
and in substitution for that certain Revolving Promissory Note dated August 31, 2006 made by Maker payable to the order of Payee in the
stated principal amount of $50,000,000 (the "Prior Note"). Accrued but unpaid interest on the Prior Note shall continue to accrue and shall be deemed to be interest owing on this note. 

        EXECUTED
on that date first above written.   

	 	 	MAKER:
	

 	
 	
CLEAN ENERGY FUELS CORP.
	

 	
 	

By: /s/ Andrew J. Littlefair
 Andrew J. Littlefair, President

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EXHIBIT 10.28

REVOLVING PROMISSORY NOTE

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