Focusing Light on Silicon Beads

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The flexible foil base means that the modules can be shaped for different applications. "You could install them on top of hybrid electric cars and curved tiles on rooftops," says Murozono.

"I think the technology works," says Branz. But the question is whether the company can make the solar cells more efficient. The cells currently being produced have efficiencies of only about 10 percent, he says. "Right now, most solar cells are 14 to 15 percent efficient."

Reducing the cost by 30 percent does not help if 30 percent more cells are needed to produce the same amount of electricity, says Branz.

Murozono says that there are ways to make the cells more efficient--for example, by improving the purity and quality of the silicon. Reducing the size of the spheres to 0.8 millimeters should also improve performance, while reducing costs even further by using 20 percent less silicon. "We are going to improve the efficiency to 13 percent within 2008, and 15 percent by 2010," Murozono says.

"There's a worldwide shortage in terms of high-quality silicon," says Charles Cromer, a researcher at the Florida Solar Energy Center, in Cocoa, FL. This shortage has largely been driven by the growth of demand for integrated circuits and solar cells, and has only served to push up the price of silicon-intensive photovoltaics. So a solar cell that uses far less silicon than its competitors should give CV21 a real edge in terms of reducing costs. "But just because they can make them cheaper doesn't mean they will be selling them half price to consumers," Cromer says.