Hoku Scientific Inc (NASDAQ: HOKU) subsidiary, Hoku Materials, just signed a pact with SunTech Power Holdings Co Ltd (NYSE: STP) wherein Hoku will sell and deliver polysilicon to Suntech beginning in mid-2009. The deal, which was announced yesterday after the markets closed, has sent the stock skyrocketing up nearly 60% to $7.97 in after-hours trading. SunTech closed yesterday at $32.28 and later gained 9c in the extended trading. Shares of Hoku and SunTech are currently trading up $7.38, or up 60.65%, and at $33.00, or up 2.11%, respectively.

The $678M agreement, which has a 10-year term and also allows either company to opt out of the last two years, provides for the delivery of polysilicon, used to make solar energy panels, at set prices. This deal follows an agreement in January between Hoku and Sanyo Electric Co Ltd (OTC: SANYY) that may bring an additional $370M in payments to the materials science company.

Hoku is currently in the process of building a $220M polysilicon production plant in Idaho in order to transition further into the solar industry. The plant will produce polysilicon for its own solar panel business, creating 200 jobs in the process, and will offer excess supply to the semiconductor market.

Analysts at investment bank Thomas Weisel believe this could be a good deal for Hoku, particularly amid its transition into the solar industry. The firm, however, is still concerned about Hoku's ability to raise $150M in debt financing, which it is seeking for the plant. Hoku believes it is currently on track with the plant, but if the company is unsuccessful in building the polysilicon plant or if it does not meet certain milestones with its products, the initial direct deposit must be returned to SunTech.