Document:

EXHIBIT 10.2
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                       STOCK PURCHASE AGREEMENT AMENDMENT
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     THIS STOCK PURCHASE AGREEMENT AMENDMENT (this "Agreement") is made and
entered into as of February 12, 2010, by and among The Quercus Trust ("Quercus"
or the "Purchaser"), and Entech Solar, Inc., a Delaware corporation (the
"Company").

     WHEREAS, the Purchaser and the Company desire to eliminate various price
protection provisions that were included in Stock Purchase Agreements entered by
them on the following dates:  December 15, 2009; January 12, 2010; January 29,
2010; and February 8, 2010 (collectively "the SPA Dates").

     NOW, THEREFORE, in consideration of the foregoing premises and the mutual
covenants and agreements herein contained, and intending to be legally bound
hereby, the parties hereto hereby agree as follows:

1. Amendment
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1.1     Price Adjustment.  Reference is made to the Stock Purchase Agreements
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(each an "SPA")  entered into by and between the Company and Quercus dated the
SPA Dates.  In order to eliminate the "price adjustment" provisions set forth
therein, Section 1.3 of the SPA dated December 15, 2009 and Section 1.2 of the
SPAs dated  January 12, 2010, January 29, 2010  and February 8, 2010 are hereby
deleted.

     2. Miscellaneous.
        -------------

2.1     Entire Agreement. This Agreement contains the entire agreement among the
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parties with respect to the amendment contemplated hereby.

2.2     Governing Law.  This Agreement shall be governed by and construed under
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the laws of the State of Delaware.

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

2.4     Severability.  The invalidity of any portion hereof shall not affect the
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validity, force, or effect of the remaining portions hereof. If it is ever held
that any restriction hereunder is too broad to permit enforcement of such
restriction to its fullest extent, the parties agree that a court of competent
jurisdiction may enforce such restriction to the maximum extent permitted by law
against those for whom it may be enforceable, and each party hereby consents and
agrees that such scope may be judicially modified accordingly in any proceeding
brought to enforce such restriction.

2.5     Further Assurances.  The parties hereto shall, without additional
        ------------------
consideration, execute and deliver or cause to be executed and delivered such
further instruments and shall take or cause to be taken such further actions as
are necessary to carry out more effectively the intent and purpose of this
Agreement.

2.6     Successors and Assigns.  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.

2.7     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.

2.8     Notices.  All notices required or permitted hereunder shall be in
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writing and shall be deemed effectively given: (i) upon personal delivery to the
party to be notified, (ii) when sent by confirmed telex or facsimile if sent
during normal business hours of the recipient, if not, then on the next business
day; (iii) five (5) days after having been sent by registered or certified mail,
return receipt requested, postage prepaid; or (iv) one (1) day after deposit
with a nationally recognized overnight courier, specifying next day delivery,
with written verification of receipt. All communications shall be sent to the
address as set forth on the signature page hereof or at such other address as
such party may designate by ten (10) days advance written notice to the other
parties hereto.

2.9     Amendments and Waivers.  Any term of this Agreement may be amended and
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the observance of any term of this Agreement may be waived (either generally or
in a particular instance and either retroactively or prospectively), only with
the written consent of the Company and Quercus. Any amendment or waiver effected
in accordance with this paragraph shall be binding upon each holder of any
securities purchased under this Agreement at the time outstanding, and each
future holder of all such securities and the Company.

                            [SIGNATURE PAGE FOLLOWS]

<PAGE>

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

                              THE QUERCUS TRUST

                              BY:  /s/ David Gelbaum
                                  ---------------------------------
                                       David Gelbaum

Address:
2309 Santiago Drive
Newport, California 92660

                              ENTECH SOLAR, INC.

                              BY:  /s/ Sandra J. Martin
                                  ---------------------------------
                                       Sandra J. Martin
                                       Chief Financial Officer

Address:
13301 Park Vista Blvd., Suite 100
Fort Worth, Texas 76177ex10_57.htm

    

    EXHIBIT
10.57

    

    

    CONTRIBUTION
AGREEMENT

    

    This
CONTRIBUTION AGREEMENT
(the “Agreement”) is made and entered into December  17, 2009, by and
between Natural Soda Holdings, Inc., a Colorado corporation (“Holdings”),
Sentient USA Resources Fund, LP, a Delaware limited partnership (“Sentient”),
and AmerAlia, Inc., a Utah corporation (“AmerAlia”).

    

    RECITALS

    

    WHEREAS, AmerAlia owns 18 % of
the capital stock of Holdings;

    

    WHEREAS, Sentient owns 82% of
the capital stock of Holdings;

    

    WHEREAS, Sentient and AmerAlia
have agreed to provide $3,000,000 of additional capital to Holdings upon and
subject to the terms and conditions set forth in this Agreement;
and

    

    NOW, THEREFORE, in
consideration of the representations, warranties and covenants set forth herein
and other valuable consideration, the receipt and sufficiency of which are
hereby acknowledged, the parties hereto agree as follows:

    

    1.           Contribution.   AmerAlia
hereby contributes $540,000 to the capital of Holdings and Sentient hereby
contributes $2,460,000 to the capital of Holdings. Holdings hereby accepts the
forgoing contributions.  The parties intend that this contribution
qualify for non-recognition pursuant to the terms of the United States Internal
Revenue Code of 1986, as amended (the “Code”) and applicable regulations
thereunder.

    

    2.           Investment Intent. In
connection with this transaction, Sentient and AmerAlia each represent and
warrant that such contributions are for investment purposes. Sentient and
AmerAlia each represent that prior to making its contribution, it has made an
investiga­tion into Holdings and its business and that Holdings has made
available to it all information with respect thereto which it needed to make an
informed decision to make the capital contribution referred to
herein.  Sentient and AmerAlia each represent that it possesses
experience and sophistication as an investor which are adequate for the
evaluation of the merits and risks of making the additional capital contribution
to Holdings. Sentient and AmerAlia acknowledge that no new shares will be issued
to it and each understands that with respect to the shares of common stock of
Holdings currently owned:

    

    (a)  That
such shares have not been registered under the Securities Act of 1933 or any
state securities law;

    

    (b)  That
the shares cannot be transferred unless registered under the Securities Act of
1933 and applicable state securities laws or pursuant to an exemption from such
registra­tion requirements;

    

    (c)  That
it must bear the economic risk of its investment for an indefinite period of
time because the shares have not been registered under the Securities Act of
1933 or any state securities laws, and, therefore, cannot be sold unless they
are subsequently registered or unless exemptions from such registration
requirements are available;

    
      
         

      

      
         

        
          

        

      

      
         

      

    

    (d)  That
any certificate representing such shares may bear a legend in substantially the
following form:

    

    THE
SECURITIES REPRESENTED HEREBY HAVE BEEN ACQUIRED FOR INVESTMENT AND HAVE NOT
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR UNDER ANY STATE
SECURI­TIES PROVISIONS.  WITHOUT SUCH REGISTRATION, SUCH
SECURI­TIES MAY NOT BE SOLD, PLEDGED, HYPOTHECATED OR OTHERWISE
TRANS­FERRED AT ANY TIME WHATSOEVER, EXCEPT UPON DELIVERY TO THE ISSUER OF
EVIDENCE SATISFACTORY TO THE ISSUER AND ITS COUNSEL THAT REGISTRATION IS NOT
REQUIRED FOR SUCH TRANSFER AND THAT ANY SUCH TRANSFER SHALL NOT BE IN
VIOLA­TION OF THE SECURITIES ACT OF 1933, AS AMENDED, OR APPLI­CABLE
STATE SECURITIES LAWS OR ANY RULES OR REGULATIONS PROMUL­GATED
THEREUNDER.

    

    3.           Further Assurances. From time
to time, at the request of either party to this Agreement and without further
consideration, the other party will execute and deliver to the other such
documents and take such other action as the other may reasonably request in
order to consummate more effective­ly the transactions described
herein.

    

    IN WITNESS WHEREOF, the
parties hereto have caused this Agreement to be executed by their duly
authorized officers or representatives as of the date and year first written
above, notwithstanding the actual date of execution.

    

    
      	
              NATURAL
      SODA HOLDINGS, INC.

            	
              AMERALIA,
      INC.

            
	 
      	 
      	 
      	 
      
	 
      	 
      	 
      	 
      
	
              By:

            	
              /s/ Peter Cassidy

            	
              By:

            	
              /s/ Bill H Gunn

            
	
              Name:

            	
              Peter
      Cassidy

            	
              Name:

            	
              Bill
      H Gunn

            
	
              Title:

            	
              President

            	
              Title:

            	
              Chairman
      & CEO

            
	 
      	 
      	 
      
	
              SENTIENT
      USA RESOURCES FUND, L.P.

            	 
      	 
      
	 
      	
              By:
      Sentient Executive MLP 1,

              Limited,
      General Partner

            	 
      	 
      
	 
      	 
      	 
      	 
      
	 
      	 
      	 
      	 
      
	
              By:

            	
              /s/ Johanna Druez

            	 
      	 
      
	
              Name:

            	
              Johanna
      Druez

            	 
      	 
      
	
              Title:

            	
              Director

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