EXHIBIT 10.120
 
May 24, 2010

Hoku Corporation
1288 Ala Moana Blvd., Suite 220
Honolulu, Hawaii 96814
Attention: Chief Executive Officer

Re: 
Financing Costs Reimbursement

Ladies and Gentlemen:

Reference is made to the Credit Agreement (the “Credit Agreement”) dated as of
the date hereof between Hoku Corporation, as borrower (“Hoku”) and China
Merchants Bank Co. Ltd., New York Branch, as lender (the “Lender”).  Capitalized
terms used but not otherwise defined herein shall have the meanings ascribed to
them in the Credit Agreement.

As an inducement and condition to the Lender’s willingness to provide a term
credit facility in an aggregate principal amount of up to $20,000,000 to Hoku on
the terms and conditions set forth in the Credit Agreement, Hoku has requested
its parent company, Tianwei New Energy Holdings Co., Ltd. (“Tianwei”), and
Tianwei has agreed, to procure a standby letter of credit (the “Letter of
Credit”) issued by China Merchants Bank Co., Ltd., Chengdu Branch in favor of
the Lender to secure Hoku’s obligations to the Lender pursuant to the Credit
Agreement.

In consideration of Tianwei’s procuring the Letter of Credit, Hoku agrees to
reimburse Tianwei for all interest, fees and expenses incurred by Tianwei
pursuant to the Letter of Credit and all other interest, fees and expenses
(including reasonable counsel fees) incurred by Tianwei in connection with the
negotiation, execution or performance of the Letter of Credit (collectively, the
“Reimbursement Obligations”), by promptly paying all amounts of the
Reimbursement Obligations requested by Tianwei in immediately available funds to
the bank account specified by Tianwei.

This letter agreement will become effective upon the execution and delivery
hereof.  This letter agreement constitutes the entire agreement between the
parties with respect to the subject matter of hereof.

This letter agreement shall be governed by and construed in accordance with the
law of the State of New York, without regard to the conflicts of law rules of
such state.

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Very truly yours,

 
TIANWEI NEW ENERGY HOLDINGS CO., LTD.
         
By:
/s/ Zheng Fei Goo
   
Name:
Zheng Fei Goo
   
Title:
General Manager

 
Agreed and accepted:
 
HOKU CORPORATION
   
By:
/s/ Scott Paul
 
Name:
Scott Paul
 
Title:
President & CEO