VOTING
      AGREEMENT

     

    This
      Voting Agreement (this “Agreement”)
      is entered into as of May 30, 2007, by and among Orion Ethanol, Inc., a Nevada
      corporation (“Orion”),
      OEI Acquisition Sub, Inc., a Delaware corporation and Orion’s wholly-owned
      subsidiary (“OEI”),
      GreenHunter Energy, Inc., a Delaware corporation (“GreenHunter”)
      and Investment Hunter, LLC, a Delaware limited liability company (“Stockholder”).
      Orion, OEI, GreenHunter and Stockholder are sometimes referred to herein as
      the
“Parties”.
      

     

    PRELIMINARY
      STATEMENT

     

    WHEREAS,
      Orion, OEI and GreenHunter are parties to that certain Agreement and Plan of
      Merger dated of even date herewith (the “Merger
      Agreement”)
      providing for, among other things, the merger (the “Merger”)
      of OEI with and into GreenHunter and the conversion of the shares of capital
      stock of GreenHunter outstanding at the time of the Merger (“Shares”)
      into the right to receive capital stock of Orion, plus cash in lieu of
      fractional shares. As an inducement to Orion, OEI and GreenHunter to enter
      into
      the Merger Agreement, Stockholder has agreed to enter into this
      Agreement.

     

    Accordingly,
      for good and valuable consideration, the receipt and sufficiency of which are
      hereby acknowledged, the Parties agree as follows:

     

    1.    Agreements
      Related to the Shares.

     

    1.1 Vote
      of Independent Investors.
      The Parties acknowledge and agree that pursuant to Section
      5.18
      of the Merger Agreement, GreenHunter has agreed to use its best efforts to
      cause
      West Coast Opportunity Fund, LLC, Centaur Value Fund L.P. and United Centaur
      Master Fund (collectively, the “Independent
      Investors”)
      (a) to vote, or to cause to be voted, all Shares that are owned or held,
      beneficially or otherwise, by all such Independent Investors in favor of (or
      to
      grant, or to cause to be granted, consents with respect to such Shares for)
      the
      recommendation made by the Board of Directors of GreenHunter with respect to
      the
      adoption and approval of the Merger Agreement and the Merger at every meeting
      of
      stockholders of GreenHunter (or any solicitation of consents in lieu thereof)
      at
      which such matters are considered and at every adjournment or postponement
      thereof; and (b) to vote, or to cause to be voted, all Shares that are owned
      or
      held, beneficially or otherwise, by all such Independent Investors (or to
      withhold, or to cause to be withheld, consents with respect to such Shares),
      in
      accordance with the recommendation of the Board of Directors of GreenHunter,
      on
      any proposal that would compete or interfere with, or that would in any way
      delay or otherwise inhibit the timely consummation of, the Merger and the other
      transactions contemplated by the Merger Agreement.

     

    1.2 Vote
      of Stockholder.
      To the extent that the Independent Investors vote or cause to be voted all
      Shares that are owned or held, beneficially or otherwise, by all such
      Independent Investors in accordance with Section 1.1 above, Stockholder agrees
      (a) to vote or to cause to be voted a proportionately equivalent number of
      Shares that are owned or held, beneficially and/or otherwise, by Stockholder
      in
      a manner and percentage identical to the vote cast by all other holders of
      GreenHunter capital stock entitled to vote in connection with the Merger
      Agreement and the Merger at every meeting of stockholders of GreenHunter (or
      any
      solicitation of consents in lieu thereof) at which such matters are considered
      and at every adjournment or postponement thereof; and (b) to vote or to cause
      to
      be voted a proportionately equivalent number of Shares that are owned or held,
      beneficially and/or otherwise, by Stockholder (or to withhold or to cause to
      be
      withheld consents with respect to such shares), in accordance with the
      recommendation of the Board of Directors of GreenHunter, on any proposal that
      would compete or interfere with, or that would in any way delay or otherwise
      inhibit the timely consummation of, the Merger and the other transactions
      contemplated by the Merger Agreement.

     

    
      
         

      

      
         

        
          

        

      

      
         

      

    

     

    1.3 No
      Voting Trusts or Transfers.
      Stockholder will not, and will not permit any person with any voting or
      dispositive power over the Shares owned or held by Stockholder to: (a) deposit
      any Shares beneficially owned by it in a voting trust or subject any Shares
      to
      any arrangement with respect to the voting of such Shares other than this
      Agreement ; (b) sell, assign, pledge, grant a lien on, or security interest
      in,
      or otherwise transfer any of its interests in, any Shares to any person; or
      (c)
      take any action that would make any representation or warranty of Stockholder
      contained herein untrue or incorrect or have the effect of limiting, preventing
      or disabling Stockholder from performing its obligations under this
      Agreement.

     

    1.4 Joinder
      Agreement.
      GreenHunter agrees that any person who is not a party to this Agreement and
      who
      acquires Shares after the date hereof, shall, upon consummation of, and as
      a
      condition precedent to the consummation of, such acquisition, execute and agree
      to be bound by terms of this Agreement and shall thereafter be deemed a
      Stockholder, with all of the obligations of Stockholder for all purposes of
      this
      Agreement.

     

    1.5 Irrevocable
      Proxy.
      At the written request of Orion, Stockholder will appoint or will cause to
      be
      appointed the Chief Executive Officer of GreenHunter (the “Proxy
      Holder”)
      as its true and lawful attorney and proxy, in the name, place and stead of
      Stockholder, to vote (in a manner and number consistent with this Agreement)
      as
      the proxy of Stockholder, the Shares beneficially owned by Stockholder at any
      and all meetings of Stockholders of GreenHunter, or any adjournments thereof,
      at
      which votes of GreenHunter’s stockholders will be taken in connection with the
      Merger or in connection with any proposal that would compete or interfere with,
      or that would in any way delay or otherwise inhibit the timely consummation
      of,
      the Merger and the other transactions contemplated by the Merger Agreement,
      giving and granting to such designated Proxy Holder all the powers Stockholder
      would possess if personally present. Such appointment also will authorize such
      Proxy Holder to execute (or to withhold) one or more written consents solicited
      in lieu of any such meeting of stockholders of GreenHunter. Such proxy is
      coupled with an interest and will be irrevocable until the date on which this
      Agreement terminates.

     

    2.    Representations
      and Warranties of Stockholder.
      Stockholder represents and warrants to Orion, OEI and GreenHunter
      that:

     

    2.1 Due
      Authority.
      Stockholder has all requisite corporate power and authority and has taken all
      corporate action necessary in order to execute and deliver, and to perform
      its
      obligations under this Agreement. This Agreement has been duly executed and
      delivered by or on behalf of Stockholder and is a valid and binding agreement
      of
      Stockholder enforceable against it in accordance with its terms, subject, as
      to
      enforcement, to laws relating to or affecting generally the enforcement of
      creditors rights, including, without limitation, bankruptcy and insolvency
      laws
      and to general principles of equity.

     

    
      
         

      

      
        2

        
          

        

      

      
         

      

    

     

    2.2 No
      Conflict; Consents.
      The execution and delivery of this Agreement by Stockholder does not, and the
      performance by Stockholder of the obligations under this Agreement and the
      compliance by Stockholder with the provisions hereof does not, (i) conflict
      with
      or violate any law, statute, rule, regulation, order, writ, judgment or decree
      applicable to Stockholder or any Shares directly or indirectly owned or held
      by
      Stockholder; (ii) conflict with or violate Stockholder's certificate of
      formation, limited liability company agreement, charter, bylaws, partnership
      agreement, trust agreement or other similar organizational documents; or (iii)
      result in any breach of or constitute a default (or an event that with notice
      or
      lapse of time or both would become a default) under, or grant to others any
      rights of termination, amendment, acceleration or cancellation of, or result
      in
      the creation of a lien or encumbrance on any of Stockholder's shares pursuant
      to, any note, bond, mortgage, indenture, contract, agreement, lease, license,
      permit, franchise or other instrument or obligation to which Stockholder is
      a
      party or by which Stockholder or Stockholder's shares are bound.

     

    (b) The
      execution and delivery of this Agreement by Stockholder does not, and the
      performance of this Agreement by Stockholder will not, require any consent,
      approval, authorization or permit of, or filing with or notification to, any
      governmental or regulatory authority by Stockholder, and except where the
      failure to obtain such consents, approvals, authorizations or permits, or to
      make such filings or notifications, could not prevent or delay the performance
      by Stockholder of his, her or its obligations under this Agreement in any
      material respect.

     

    2.3 Ownership
      of Shares.
      Stockholder is the sole record and beneficial owner of 14,560,000 Shares, all
      of
      which Shares are, on the date hereof, and will at all times during the term
      will
      be, held free and clear of any liens, claims, options, charges, proxies or
      voting restrictions or other encumbrances.

     

    2.4 Additional
      Documents.
      Stockholder hereby covenants and agrees to execute and deliver any additional
      documents necessary to carry out the intent of this Agreement.

     

    3.    Miscellaneous.

     

    3.1 Governing
      Law.
      THIS AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES UNDER THIS
      AGREEMENT WILL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH AND SUBJECT
      TO
      THE LAWS OF THE STATE OF DELAWARE, WITHOUT REFERENCE TO CONFLICTS OF LAWS
      PRINCIPLES.

     

    3.2 Venue.
      The Parties hereby irrevocably submit to the jurisdiction of the courts of
      the
      State of Texas and the federal court of the United States of America located
      in
      the State of Texas solely in respect of the interpretation and enforcement
      of
      the provisions of this Agreement and of the documents referred to in this
      Agreement and in respect of the transactions contemplated hereby, and hereby
      waive, and agree not to assert, as a defense in any action, suit or proceeding
      for the interpretation or enforcement hereof or of any such document, that
      it is
      not subject thereto or that such action, suit or proceeding may not be brought
      or is not maintainable in such courts or that the venue thereof may not be
      appropriate or that this Agreement or any such document may not be enforced
      in
      or by such courts, and the Parties irrevocably agree that all claims with
      respect to such action or proceeding will be heard and determined in such a
      Texas state or federal court. Each Party consents to and grants any such court
      jurisdiction over the person of such Party and over the subject matter of such
      dispute and agrees that mailing of process or other papers in connection with
      any such action or proceeding in the manner provided in Section 3.3 herein
      or in
      such other manner as may be permitted by law will be valid and sufficient
      service thereof.

     

    
      
         

      

      
        3

        
          

        

      

      
         

      

    

     

    (b) Each
      Party acknowledges and agrees that any controversy that may arise under this
      agreement is likely to involve complicated and difficult issues, and therefore
      each such Party hereby irrevocably and unconditionally waives any right such
      Party may have to a trial by jury in respect of any litigation directly or
      indirectly arising out of or relating to this agreement, or the transactions
      contemplated by this agreement. Each Party certifies and acknowledges that
      (i)
      no representative, agent or attorney of any other Party has represented,
      expressly or otherwise, that such other Party would not, in the event of
      litigation, seek to enforce the foregoing waiver, (ii) each Party understands
      and has considered the implications of this waiver, (iii) each Party makes
      this
      waiver voluntarily, and (iv) each Party has been induced to enter into this
      agreement by, among other things, the mutual waivers and certificates in this
      paragraph (b).

     

    3.3 Notices.
      All notices, requests, claims, demands and other communications required or
      permitted to be given or made pursuant to this Agreement will be in writing
      and
      will be deemed given (i) on the first business day following the date received,
      if delivered personally or by telecopy (with telephonic confirmation of receipt
      by the addressee), (ii) on the business day following timely deposit with an
      overnight courier service, if sent by overnight courier specifying next day
      delivery and (iii) on the first business day that is at least five days
      following deposit in the mails, if sent by first class mail, to the Parties
      at
      the following addresses (or at such other address for a Party as will be
      specified by like notice):

     

    
      	
              To
                Orion and/or OEI

            	
              Orion
                Ethanol, Inc.

              307
                South Main Street

              Pratt,
                Kansas 67124

              Attention:
                Chief Financial Officer

              Telephone
                (620) 672-2814 

              Facsimile:
                (620) 672-3142

            
	 	 
	
              with
                copies to:

            	
              Thelen
                Reid Brown Raysman & Steiner LLP

              701
                8th Street

              Suite
                800

              Washington,
                D.C. 20001

              Attn:
                Joseph R. Tiano, Jr. and Louis A. Bevilacqua

              Telephone:
                (202) 508-4000

              Facsimile:
                (202) 508-4321

            


    

     

    
      
         

      

      
        4

        
          

        

      

      
         

      

    

     

    
      	
              To
                Investment Hunter

            	
              _______________________________

              _______________________________

              _______________________________

              Attn:
                Gary Evans

              Telephone
                (_____) __________

              Facsimile:
                (_____) __________

            
	 	 
	
              To
                GreenHunter:

            	
              GreenHunter
                Energy Inc.

              3129
                Bass Pro Drive

              Grapevine,
                Texas 76051

              Attn:
                Michael K. Studer, President

              Telephone
                (469) 293-4397

              Facsimile:
                (972) 550-7464

            
	 	 
	
              with
                copies to:

            	
              GreenHunter
                Energy Inc.

              3129
                Bass Pro Drive

              Grapevine,
                Texas 76051

              Attn:
                Morgan F. Johnston, Vice President, General Counsel and
                Secretary

              Telephone
                (469) 293-4397

              Facsimile:
                (972) 550-7464

               

              and

               

              Fulbright
                & Jaworski L.L.P.

              2200
                Ross Avenue, Suite 2800

              Dallas,
                Texas 75201

              Attn:
                David E. Morrison

              Telephone:
                (214) 855-8301

              Facsimile:
                (214) 855-8200

            


    

     

    3.4 Severability.
      The provisions of this Agreement will be deemed severable and the invalidity
      or
      unenforceability of any provision will not affect the validity or enforceability
      of the other provisions hereof. If any provision of this Agreement, or its
      application to any person or any circumstance, is invalid or unenforceable,
      (i)
      a suitable and equitable provision will be substituted therefor in order to
      carry out, so far as may be valid and enforceable, the intent and purpose of
      such invalid or unenforceable provision and (ii) the remainder of this Agreement
      and the application of such provision to other persons or circumstances will
      not
      be affected by such invalidity or unenforceability, nor will such invalidity
      or
      unenforceability affect the validity or enforceability of such provision, or
      the
      application thereof, in any other jurisdiction.

     

    3.5 Counterparts.
      This Agreement may be executed in any number of counterparts, each of which
      will
      be deemed to be an original and all of which will together constitute the same
      agreement.

     

    3.6 Termination;
      Survival.
      This Agreement will terminate upon (i) the mutual written consent of all
      Parties; (ii) the time the Merger becomes effective; or (iii) the termination
      of
      the Merger Agreement in accordance with its terms, and all the provisions of
      this Agreement will terminate at such time.

     

    
      
         

      

      
        5

        
          

        

      

      
         

      

    

     

    3.7 Captions.
      All captions in this Agreement are for convenience of reference only and are
      not
      part of this Agreement, and no construction or reference will be derived
      therefrom.

     

    3.8 Specific
      Performance.
      Each Party acknowledges that it will be impossible to measure in money the
      damage to the other Parties if such Party fails to comply with any of the
      obligations imposed by this Agreement, that each such obligation is material
      and
      that, in the event of any such failure, the other Party will not have an
      adequate remedy at law or damages. Accordingly, each Party agrees that
      injunctive relief or any other equitable remedy, in addition to remedies at
      law
      or damages, is the appropriate remedy for any such failure and will not oppose
      the granting of such relief on the basis that the other Party has an adequate
      remedy at law or in the form of damages. Each Party agrees that it will not
      seek, and agrees to waive any requirement for, the securing or posting of a
      bond
      in connection with any other Party’s seeking or obtaining such equitable
      relief.

     

    3.9 Successors
      and Assigns.
      This Agreement will be binding upon and inure to the benefit of the Parties
      and
      their respective successors and permitted assigns and will not be assignable
      without the written consent of all other Parties hereto.

     

    3.10 Entire
      Agreement; Amendment; Waiver.
      This Agreement (including any schedules hereto) and the Merger Agreement
      (including any exhibits and schedules thereto) supersede all prior agreements,
      written or oral, among the Parties with respect to the subject matter hereof
      and
      contain the entire agreement among the Parties with respect to the subject
      matter hereof. This Agreement may not be amended, supplemented or modified,
      and
      no provision hereof may be modified or waived, except by an instrument in
      writing signed by all the Parties or, in the case of a waiver, each Party
      granting such waiver. No waiver of any provision hereof by any Party will be
      deemed a waiver of any other provision hereof by any such Party, nor will any
      such waiver be deemed a continuing waiver of any provision hereof by such
      Party.

     

    3.11 Further
      Assurances.
      The Parties will execute and deliver such additional instruments and other
      documents and will take such further actions as may be necessary or appropriate
      to effectuate, carry out and comply with all of the terms of this Agreement
      and
      the transactions contemplated hereby.

     

    3.12 Third
      Party Beneficiaries.
      Nothing in this Agreement, express or implied, is intended to confer upon any
      third party any rights or remedies of any nature whatsoever under or by reason
      of this Agreement.

     

    
      
         

      

      
        6

        
          

        

      

      
         

      

    


    IN
      WITNESS WHEREOF, the parties have executed this agreement as of the date first
      written above.

     

    
      	 	ORION ETHANOL 
	 	 
	 	
              By:_____________________________

              Name:___________________________

              Its:_____________________________

              


               

              OEI
                ACQUISITION SUB, INC. 

               

              By:_____________________________

              Name:___________________________

              Its:_____________________________

               

               

              GREENHUNTER
                ENERGY, INC.

               

              By:_____________________________

              Name:___________________________

              Its:_____________________________

               

               

              INVESTMENT
                HUNTER LLC

               

              By:_____________________________

              Name:___________________________

              Its:_____________________________

            


    

     

    


     

    [Signature
      Page to Investment Hunter Voting Agreement]

     

    
      
         

      

      
        7