SolarWorld Grade Silicon

Securing silicon through long-term contracts, in-house production, and recycling.

SolarWorld Secures Sustainable Solar-Grade Silicon Supplies Through In-House Production, Recycling and Long-Term Contracts with Renowned Manufacturers (Deutsch) was the news Tuesday, August 12, 2008. SolarWorld AG’s (FRA:SWV) wholly owned subsidiary, Deutsche Solar AG, secured an additional $580 million polysilicon contract with DC Chemical Co., Ltd. (SEO:010060) for delivery by 2016. At the same time, additional long-term wafer supply contracts worth over $350 million “were concluded with customers in Germany and China.

SolarWorld plans for in-house solar grade silicon production are detailed in the above slide titled “Ramp up internal silicon capacity” from the July 2008 Presentation of the Chief Financial Officer. Both the Joint Solar Silicon GmbH & Co. KG and Scheuten SolarWorld Solicium GmbH joint ventures are developed and managed by the Sunicon AG subsidiary. The SolarMaterial subsidiary recycles silicon for SolarWorld.

Just last Friday, August 8, 2008, SolarWorld and joint venture partner Evonik Industries AG inaugurated the first Joint Solar Silicon GmbH & Co. KG (JSSI) production plant in Rheinfelden (Baden) Germany per SolarWorld AG: Start of Industrial Production of Solar-Grade Silicon (Deutsch) or Evonik and SolarWorld Open New Solar Silicon Plant—New Production Process with Impressive Energy-Saving Features. Evonik said the new solar silicon production process:

requires only 10 percent of the energy used by conventional processes and is more cost efficient. The integrated production facility consists of a monosilane production plant operated by Evonik and a second plant in which JSSi uses the chemical to produce solar silicon. The production capacity will initially be 850 metric tons of solar silicon per year.

Three reactors will be used to reach the 850 and later 1000 MT (metric ton) annual silicon production capacity. The total investment by Evonik (51 per cent) and SolarWorld AG (49 per cent) in the JSSI joint venture production facility was said to be in the coy double digit million Euro range (~$10 to $99 million).

Deutsche Solar AG CEO Prof. Dr. Peter Woditsch presented two slides about the JSSI process at the 2nd PV Industry Forum before Intersolar 2006. Please see the Picasa Slideshow below.

Pyrolysis of SiH4 (monsilane) in tube reactor at 800°C
Monosilane is decomposed in hydrogen resulting in the chemical vapor deposition of silicon on the tube reactor walls and a silicon powder byproduct. SolarWorld claims the deposition process is protected by four patents exclusive to the JSSI joint venture.

Per the JSSI website, the Evonik (was Degussa AG) and SolarWorld joint venture was formed way back on May 24, 2002. Evonik would supply silane to JSSI while SolarWorld contributed the silane decomposition in tube reactor process technology. Although SolarWorld has a number of patents related to solar grade silicon, monosilane, and trichlorosilane production processes, SolarWorld obtained an exclusive license to the JSSI silicon process technology from GT Equipment Technologies, Inc., now well known as recent IPO GT Solar International, Inc. (NASDAQ:SOLR). Here is the original press release:

GT Equipment Technologies, Inc. licenses groundbreaking silicon feedstock production technology to SolarWorld AG

and the international patent published by the World Intellectual Property Organization (WIPO):


I have no doubt significant research and development efforts were required by JSSI to commercialize this silicon deposition process over the last six years.

Greentech Media has a good post, Timminco Shares Fall on Production Delay, about their production challenges in the ramp up of solar grade silicon. I have not had a chance yet to listen to the conference call.

Leave a Reply

Your email address will not be published. Required fields are marked *