Hoku and Solargiga Sign $455 Million Polysilicon Supply Contract

Hoku Materials, Inc., a wholly owned subsidiary of Hoku Scientific, Inc. (NASDAQ: HOKU) established to manufacture and sell polysilicon for the solar market, and Wealthy Rise International, Ltd., a wholly owned subsidiary of Solargiga Energy Holdings, Ltd. (HKG: 0757), a manufacturer of monocrystalline ingots and wafers in China, today announced the signing of a definitive contract for Hoku's sale and delivery of polysilicon to Solargiga over a ten-year period beginning in early 2010.

According to the contract, up to approximately $455 million may be payable to Hoku during the ten-year period, subject to product deliveries and other conditions. The contract provides for the delivery of predetermined volumes of polysilicon each year, with the first shipment in the first quarter of 2010 and the remainder over a ten-year period at set prices that will decline throughout the term of the agreement. The contract also provides for a deposit of $22 million to Hoku within 15 days, and requires that Solargiga make additional deposits for products in the amount of $21 million by December 20, 2008, $20 million by March 31, 2009, and $5 million upon first shipment. Under the agreement, Hoku will grant to Solargiga a security interest in its polysilicon assets to secure Hoku's obligation to repay $68 million to Solargiga as a credit against product shipments over time.

"This agreement with Hoku is key to our company's expansion plans," said Solargiga's president and executive director, Wenhua Tan. "Solargiga is currently the number two producer of monocrystalline ingots in China but we are implementing an aggressive plan to double our capacity by the end of 2009. We selected Hoku to supply us with polysilicon because they share Solargiga's focus on delivering only the highest possible quality product, and because -- like us -- they believe in the importance of establishing a long-term partnership."

"We are pleased to enter into this long-term supply agreement with Solargiga," said Dustin Shindo, chief executive officer of Hoku Scientific. "They are an established leader in the global solar market, and Solargiga's strong expansion plans coupled with their demonstrated commitment to technology and innovation make them an excellent strategic partner for Hoku."

About Hoku Scientific, Inc.

Hoku Scientific, Inc. (NASDAQ: HOKU) is a diversified clean energy technologies company with three business units: Hoku Materials, Hoku Solar and Hoku Fuel Cells. Hoku Materials plans to manufacture, market, and sell polysilicon for the solar market from its plant currently under construction in Pocatello, Idaho. Hoku Solar provides turnkey photovoltaic systems in Hawaii. Hoku Fuel Cells has developed proprietary fuel cell membranes and membrane electrode assemblies for stationary and automotive proton exchange membrane fuel cells. For more information visit www.hokuscientific.com.

Hoku ®, Hoku Scientific ®, Hoku Solar(TM) and Hoku Fuel Cells(TM) are trademarks of Hoku Scientific, Inc., and Hoku Materials(TM) is a trademark of Hoku Materials, Inc.

About Solargiga Energy Holdings, Ltd. and Wealthy Rise International, Ltd.

Solargiga Energy Holdings Limited (HKG: 0757) is an investment holding company. The Company, along with its subsidiaries, is engaged in the trading of, manufacturing of and provision of processing services for monocrystalline silicon ingots/wafers. Its subsidiaries include Jinzhou Yangguang Energy Co. Ltd, Jinzhou Rixin Silicon Materials Co., Ltd., and Wealthy Rise International Limited. In June 2007, it acquired Solar Technology Investment (Cayman) Corp. (Solartech), Shanghai Jingji Electron aterial Co., Ltd. (Shanghai Jingji) and Jinzhou Youhua New Energy Co., Ltd. (Jinzhou Youhua), which comprised, amongst others, established polysilicon reclaiming and upgrading facilities and monocrystalline silicon ingot manufacturing facilities. Wealthy Rise International was incorporated in Hong Kong on June 21, 2007 to act as the intermediate holding company for all PRC-incorporated group companies, and engages in the trading of raw materials, ingots and wafers. www.solargiga.com

Forward-Looking Statements

This press release contains forward-looking statements that involve many risks and uncertainties. These statements relate to Hoku Materials's ability to successfully derive revenues from the sale of polysilicon to Wealthy Rise International, Ltd. and Solargiga Energy Holdings, Ltd., Tianwei New Energy, Kinko Energy, Solarfun, and Suntech; the timing of Hoku aterials's receipt of future prepayments in the aggregate amount of $68 million from Solargiga; its ability to successfully raise sufficient funds to establish a polysilicon manufacturing plant; its ability to engineer and construct a production plant for polysilicon; its ability to manufacture polysilicon; its ability to meet the delivery schedule in its agreement with Solargiga; the quality of polysilicon to be manufactured; Hoku aterials's costs to manufacture polysilicon, and its ability to offer pricing that is competitive with competing products; Solargiga's plans to expand its silicon ingot and wafer businesses; Hoku Scientific and Solargiga's future financial performance; their respective business strategies and plans; and objectives of each company's management for future operations. In some cases, you can identify forward-looking statements by terms such as "anticipate," "believe," "can," "continue," "could," "estimate," "expect," "intend," "may," "plan," "potential," "predict," "project," "should," "will," "would" and similar expressions intended to identify forward-looking statements. These statements involve known and unknown risks, uncertainties and other factors that may cause Hoku Scientific and/or Solargiga's actual results, performance, time frames or achievements to be materially different from any future results, performance, time frames or achievements expressed or implied by the forward-looking statements. Given these risks, uncertainties and other factors, you should not place undue reliance on these forward-looking statements. In evaluating these statements, you should specifically consider the risks described in Hoku Scientific's filings with the Securities and Exchange Commission, and Solargiga's filings with the Hong Kong Stock Exchange, as applicable. Except as required by law, neither Hoku Scientific nor Solargiga assumes an obligation to update these forward-looking statements publicly, or to update the reasons actual results could differ materially from those anticipated in these forward-looking statements, even if new information becomes available in the future.