|   | (i) | Deliver the Letter of Credit by July 8th, 2011 in the amount of $635,999.50. |
|--------|-----|------------------------------------------------------------------------------|

|   | (ii) | Upon the earlier of successful acceptance testing at Hoku’s facility in Pocatello, Idaho, and July 30, 2011, Hoku shall pay the amount of $317,999.75 (the “Second Payment”). |
|--------|------|-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

|   | (iii) | Upon the earlier of 6 months after the date of commissioning and December 31, 2011, Hoku shall pay the amount of $317,999.75 (the “Third Payment”). |
|--------|-------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------|

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|   | Dr. Martin Strassner PVA TePla Danmark June 24, 2011Page of 2 of 2 |
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|                  |   | Accepted and Agreed as of        June 27             , 2011                                                                                                                        |   |
|-----------------------|--------|-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------|
|                  |   |                                                                                                                                                                                                                                                                              |   |   |
| HOKU MATERIALS, INC   |   | PVA TEPLA DANMARK                                                                                                                                                                                                                                                                 |   |   |
|                  |   |                                                                                                                                                                                                                                                                              |   |   |
|                  |   | By:       /s/ Martin Strassner                                                                                              |   |   |
|                  |   |              Martin Strassner, Branch Manager                                                                                                                                                                         |   |   |
| /s/ Mike Zhang        |   |                                                                                                                                                                                                                                                                              |   |   |
| Mike Zhang, President |   |              /s/ Arnd Bohle                                |   |   |
|                  |   |              Arnd Bohle, CFO                                                                                                                                                                                     |   |   |
|                  |   |                                                                                                                                                                                                                                                                              |   |   |