March 13, 2009       

Continental Stock Transfer & Trust Company
17 Battery Place
New York, NY  10004
Attn: Steven Nelson
 
Re:  Proposed Transfer of Certain Shares of Common Stock of
Tremisis Energy Acquisition Corporation II

Dear Mr. Nelson:

Pursuant to that certain Stock Escrow Agreement (the “Escrow Agreement”) dated
December 6, 2007 by and among Tremisis Energy Acquisition Corporation II (the
“Company”), Continental Stock Transfer & Trust Company (the “Escrow Agent”),
Lawrence S. Coben, Ronald D. Ormand, Jon Schotz, Charles A. Norris, Stephen N.
Casati, Bill Goldstein, Dean Vanech, Jerry Doren, Owen Coleman, Bill Armstrong,
Trevor Wilson, Brian McInerney, Richard Kassar, David Levine, Jim Land, David A.
Preiser, Gary C. Evans and Jonathan Jacobs (collectively, the “Initial
Stockholders”), the Escrow Agent is currently holding in escrow the shares of
the Company’s common stock owned by each of the Initial Stockholders in the
amounts identified in Schedule A (the “Escrow Shares”).

The Initial Stockholders have executed an agreement (the “Put/Call Agreement”)
of even date herewith pursuant to which they have agreed to transfer a portion
of each Initial Stockholders’ Escrow Shares in the amounts identified in
Schedule A (the “Transfer Shares”) in a private transaction to SoftForum Co.,
Ltd. and Sang-Chul Kim (the “Investors”), for no cash consideration upon the
Company’s consummation of a Business Combination (as such term is defined in the
Put/Call Agreement).  The Escrow Shares and the Transfer Shares will remain in
escrow with you pursuant to the terms of the Escrow Agreement, but after the
consummation of a Business Combination, you will hold the Transfer Shares on
behalf of the Investors and not us.  As Escrow Agent, you acknowledge and agree
not to enter into any control or other agreement relating to, or deliver
possession of, the Transfer Shares to any third party, other than the Investors,
that could create or perfect a security interest in the Transfer Shares.

Further, in connection with our agreement to transfer the Transfer Shares to the
Investors, we are attaching executed stock powers with respect to the Transfer
Shares.  Please hold these stock powers in escrow, together with the Transfer
Shares, and upon consummation of a Business Combination, kindly effect the
transfer of the Transfer Shares to the Investors. The Investors are agreeing to
be bound by the terms and conditions of the Escrow Agreement and will deliver
the appropriate stock powers to the Escrow Agent.
 

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This letter shall serve as irrevocable instructions from the Initial
Stockholders to you as the Escrow Agent with respect to the transfer of the
Transfer Shares upon consummation of the Business Combination and may not be
altered by any of us in the future, except upon termination of the Put/Call
Agreement in accordance with its terms

Very truly yours,
     
INITIAL STOCKHOLDERS:
     
/s/ Lawrence S. Coben
 
Lawrence S. Coben
     
/s/ Ronald D. Ormand
 
Ronald D. Ormand
     
/s/ Jon Schotz
 
Jon Schotz
     
/s/ Charles A. Norris
 
Charles A. Norris
     
/s/ Stephen N. Casati
 
Stephen N. Casati
     
/s/ Bill Goldstein
 
Bill Goldstein
     
/s/ Dean Vanech
 
Dean Vanech
     
/s/ Jerry Doren
 
Jerry Doren
     
/s/ Owen Coleman
 
Owen Coleman
 

[Signature Page - Transfer Shares Release Letter]
 

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/s/ Bill Armstrong
 
Bill Armstrong
     
/s/ Trevor Wilson
 
Trevor Wilson
     
/s/ Brian McInerney
 
Brian McInerney
     
/s/ Richard Kassar
 
Richard Kassar
     
/s/ David Levine
 
David Levine
     
/s/ Jim Land
 
Jim Land
     
/s/ David A. Preiser
 
David A. Preiser
     
/s/ Gary C. Evans
 
Gary C. Evans
     
/s/ Jonathan Jacobs
 
Jonathan Jacobs
 

The undersigned acknowledge and consent to the foregoing terms.

THE COMPANY:

TREMISIS ENERGY ACQUISITION CORPORATION II

By:
/s/ Lawrence S. Coben  
Name:
Lawrence S. Coben  
Title:
Chief Executive Officer

ESCROW AGENT:

CONTINENTAL STOCK TRANSFER & TRUST COMPANY

By:
/s/ Alexandra Albrecht  
Name:
Alexandra Albrecht  
Title:
Vice President

[Signature Page - Transfer Shares Release Letter]
 

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Schedule A

Name of Stockholder
 
Escrow Shares
   
Transfer Shares
               
Lawrence S. Coben
    827,726       794,187                    
Ronald D. Ormand
    827,726       794,187                    
Jon Schotz
    144,822       138,391                    
Charles A. Norris
    144,822       138,391                    
Stephen N. Casati
    19,322       18,528                    
Bill Armstrong
    42,185       40,451                    
Dean Vanech
    37,500       35,959                    
Jerry Doren
    28,125       26,969                    
Owen Coleman
    28,125       26,969                    
Bill Goldstein
    28,125       26,969                    
Trevor Wilson
    28,125       26,969                    
David A. Preiser
    18,750       17,979                    
Brian McInerney
    14,063       13,485                    
Richard Kassar
    14,063       13,485                    
David Levine
    14,063       13,485                    
Jim Land
    14,063       13,485                    
Jonathan Jacobs
    14,063       13,485                    
Gary C. Evans
    187,500       179,794  

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