Amid a major expansion program, Global Solar Energy Inc. (GSE) claims to have achieved a breakthrough for solar cells based on copper indium gallium diselenide (CIGS) thin-film technology.

GSE (Tucson, Ariz.) said that its CIGS-based, thin-film cells have achieved an average of 10 percent efficiency "on a flexible, lightweight substrate over several production runs." Starting in 2007, the company's solar cells achieved an average efficiency of about 9 percent.

The privately-held company is also expanding its production base amid the ongoing growth in the solar-cell industry. It plans to announce a new plant in Tucson, which is slated for production in March. Last year, GSE announced a new plant in Berlin, Germany, which is scheduled for production in mid-2008.

In 2007, GSE capped off a record year in which the company manufactured and shipped 4 megawatts (MW) of photovoltaic products. Over time, the company hopes to have a total capacity of 65 MW.

Other thin-film, solar-cell suppliers, including First Solar Inc. and United Solar Ovonic, are also in the process of expanding their capacities. "The demand for [solar energy] is still pent up," said Tim Teich, vice president of sales and marketing at GSE, in an interview.

Thin-film products are especially hot, given the ongoing shortages of polysilicon materials. Conventional solar cells make use of polysilicon, while the thin-film products use little of none of these materials.

The company's proprietary process claims to produce among the "highest efficiency" solar cells in the thin-film market. In comparison, high-flying First Solar, which uses a cadmium telluride (CdTe) technology, is said to have efficiencies in the 10 percent range. First Solar's average module conversion efficiency is 10.5 percent as of September 2007, according to that company.

GSE has made a big step by boosting its average efficiency to 10 percent. "This is a big milestone," Britt said. "A number of CIGS thin-film companies have exceeded 10 percent efficiency in the lab or in individual cells, but achieving 10 percent average solar cell efficiency over the course of several sustained, continuous production runs is a significant achievement."

"As of January 2008, there are currently 185 solar module prices below $4.75 per watt, or 11.7 percent of the total sample. This compares with 215 prices below $4.75 per watt in December," according to the firm.