Global Solar Energy wants you to know two things today: Its copper-indium-gallium-diselenide (CIGS) cells could covert as much as 15.45 percent of the sunlight that falls on them into electricity; and, it's pursuing sales in the so-called building integrated photovoltaic (BIPV) market, where solar cells are embedded into building components instead of encased in glass panels and parked on a rooftop.
The company's interest in the BIPV market isn't new. Global Solar said in April 2008 that it would join Dow Building Solutions, part of Dow Chemical, to develop solar roof shingles as part of a project funded by the U.S. Department of Energy.
The Tucson, Ariz.-based company still isn't willing to say much about any other customers or installations showcasing its technology. But Global Solar expects to see commercial products with its thin films launched for the BIPV market next year, said Tim Teich, VP of sales and marketing.
"We are going to do BIPV and put it into building products instead of putting it in the dinosaur glass modules. We are using solar films where no solar has gone before," Teich said.
BIPV is a new market with lots of promises. Plenty of other companies – including CIGS thin-film maker Ascent Solar Technologies in Thornton, Colo. – are looking at turning their solar technologies into roofing products or windows.
There aren't many truly integrated solar building materials on the market, and they are expensive. But exploring the BIPV market aggressively could be wise at a time with silicon solar cells getting incredibly cheap and dominates the global solar market.
Global Solar is one of the earlier developers of CIGS thin films. The company deposits the CIGS materials on a roll of flexible stainless steel to make the solar cells, which are then connected 18 of them together to form a strip (or string, as the company calls it).
The company sells the strings to companies that assemble them into panels. This model eliminates the need for the company to invest in factories to make the final products, and strings are a lighter and cheaper to ship than panels, which are typically encased in glass.
Global Solar started selling the strings last summer, but has remained largely mum about the customers that are making CIGS panels from its cells. Solon, a Germany-based solar panel maker, owns 19 percent of Global Solar.
Solon made the panels used for a 750-kilowatt system installed on the grounds of Global Solar's factory in Tucson. Global Solar announced the installation last December and called it the first commercial-scale deployment of its products.
The solar company has a 40-megawatt factory in Tucson and a 35-megawatt factory in Germany. Global Solar had planned add another 100 megawatts of production capacity by the end of 2009, but scratched the idea when the recession hit, Teich said. The company's is running its factories at 50 percent capacity, he added.
Last year, Global Solar said its cells could achieve 10 percent efficiency. The company has since made cells from its production line that could achieve 15.45 percent efficiency, a figure verified by the National Renewable Energy Laboratory.
Solar companies typically send their best cells to the lab for testing and verification. Those that roll out of factories could have lower efficiencies.
Global Solar is making strings that could get as high as 11.7 percent, Teich said. The average is between 10 percent and 11 percent, he added. When assembled into a panel, the efficiencies are likely to drop further since not all cells coming off a production line have exactly the same efficiency.
Raising efficiencies is crucial for the company to offer more attractive products and reduce manufacturing costs. Teich declined to disclose the production cost.
Other CIGS thin-film makers have been reporting higher efficiencies lately. Germany-based Solibro announced just Tuesday that it is producing panels at 12 percent efficiency.
Last week, Nanosolar in San Jose, Calif., said its CIGS cells could achieve 16.4 percent. But the medium efficiency of the cells rolling off its production lines falls between 11 percent and 12 percent (see Nanosolar Boosts Cell Efficiency, Starts Mass Production).
NuvoSun, a newer entrant based in Palo Alto, Calif., said last month it had produced a test cell that could reach 11.8 percent. Mass-producing cells is more complex than making a test cell, so the efficiency of market-ready cells would be lower.