News and New Products

Dow Corning: Solar Now Primary Focus

By Ann Steffora Mutschler -- Electronic News, 9/4/2006

To increase the availability of solar material feedstock to the photovoltaic industry, providing new options to ingot, wafer and cell producers, Midland, Mich.-based Dow Corning Corp. is announcing today that it has achieved a milestone in solar energy technology.

As part of its new primary focus on the solar industry, the company has created solar-grade (SoG) silicon derived from metallurgical silicon that exhibits good solar cell performance characteristics when blended with traditional polysilicon feedstock, according to Ga§×tan Borgers, director of Dow Corning Solar Solutions.

This silicon feedstock material, Dow Corning PV 1101 SoG Silicon, is believed to be the first commercially available feedstock produced from such technology using large scale manufacturing processes.

Since most solar cells require silicon in a very pure form, polycrystalline silicon (poly-Si), originally developed for the electronics industry, has been the option so far. However, Dow has identified other technologies that do not require poly-Si.

Since 2004, a shortage in poly-Si has limited the growth of the photovoltaic industry, with silicon feedstock availability a primary obstacle to the further expansion, at the same time the demand for megawatts peak (MWp) produced by solar modules is expected to increase more than four-fold by 2010, according to Michael G. Rogol, consultant for Photon Consulting, a unit of Solar Verlag GmbH. As a result, a new supply solution is needed.

Dow Corning's Borgers reminded that the company entered the photovoltaic market in 2001 based on the company's 60 years of experience in silicon based chemistry including silicon metal, silicones and silanes.

In addition, the company is well-positioned thanks to its majority share in Hemlock Semiconductor Corp., one of the world's largest producer of poly-Si and one of the leading silicon feedstock supplier to the semiconductor and solar industries.

The company also boasts an advanced metallurgical facility, part of Companhia Brasileira Carbureto de Clecio, is located in Santos Dumont, Brazil that is dedicated to supplying this alternative solar-grade feedstock.

Dow Corning says the key advantages to its approach include the fact that it is being done on an industrial scale.

PV 1101 SoG Silicon can be blended with polycrystalline to create solar-grade silicon, thereby serving as a complement to existing feedstock, which should help the photovoltaic industry achieve continued growth by extending material availability, as well as extending business and technical options, Borgers explained.

From that business perspective, the blend can be adjusted based on need, allowing for the mix to be fit to the application, he said.

"This is a first step, and Dow will continue development for more options in the future. We wanted to get to market quickly since it has a lot of value, and we will further refine the product and release new generations in the future, after successful development," Borgers noted.

"PV 1101 is certainly one of the most innovative technologies to come along in the solar energy industry since the manufacture of the first silicon solar cells," he continued.

"For years now, the solar industry has hoped to be supplied by new sources of silicon designed and dedicated to them. PV 1101 is a major step in that direction. It is a step that will provide a means of growth for the solar industry," Borgers added.

The PV 1101 blend material has already been tested in independent institutes and at several Dow Corning Solar Solutions customer production sites worldwide. The testing showed that the blended feedstock material exhibits performance characteristics similar to polysilicon in terms of solar cell manufacturing and efficiency, and the company has already received orders for the material.

Dow Corning began bulk production of PV 1101 earlier this summer with bulk customer shipments commencing last month.

Ramping up of the PV 1101 SoG Silicon production facility to full speed is currently in progress, the company concluded.