Solar in China: Applied Materials engineers in the Solar Technology Center in Xi’an, China.
Its strategy, says Pinto, is to “help drive down costs through scaling.” The company developed equipment for building amorphous-silicon solar cells on thin glass panels the size of a garage door, 5.7 square meters. These sheets can then be sliced into smaller panels or left as they are. Working at this scale saves money; Applied Materials made it work by developing equipment that can coat the huge panels with uniform silicon films just nanometers thick.
To compete in both the U.S. and Chinese markets, says Ken Zweibel, director of the George Washington Solar Institute, the company will need to increase the efficiency of the solar cells that can be made using its equipment. “Amorphous silicon has a relatively low cost, but its efficiency is the lowest of all the thin-film solar cells,” says Zweibel. Cells made of cadmium telluride that are sold by U.S. thin-film company First Solar have an efficiency of around 11 percent. The amorphous-silicon solar cells made on Applied Materials’s equipment are at just over 8 percent. “The 3 percent difference in efficiency is a 30 percent difference in terms of overall cost,” Zweibel notes.
Pinto says research at the Xi’an center will focus on products suited to the way that country’s population is concentrated, in cities with tall buildings. “Cities in China don’t have very much rooftop” on which to place solar cells, says Pinto. The company plans to develop technologies such as electrochromic windows, which save heating and cooling costs by changing color with the weather. Solar cells embedded in windows might act both as a shade and an energy source. The company is also researching LED lighting and plans to work on thin-film batteries.