GE places solar bets on thin-film cells
Working with start-up PrimeStar Solar, General Electric is developing solar modules that use low-cost, cadmium telluride thin-film solar cells.
General Electric, which has long made solar panels using traditional silicon, is converting to thin-film cells, using the same material as industry cost leader First Solar.
The company's research organization on Thursday detailed its activities with cadmium telluride solar cells, which the company has determined offers the most potential to lower solar power costs.
As first reported by CNET, GE's next-generation solar panels are based on technology from PrimeStar Solar, a Denver, Colo.-based company where GE is the majority owner. GE executives are bullish that by lowering costs, solar can grow rapidly, as its wind business has done.
GE has not yet begun manufacturing solar panels using the thin-film technology but it plans to do so some time in 2011, according to a company representative.
There are several companies developing thin-film solar cell technology, which promise to lower the cost of manufacturing and use less material. But thin-film solar cells are less efficient at producing electricity than crystalline silicon cells.
GE chose to go with cadmium telluride because it offers the most potential for overall cost savings, said Danielle Merfeld, the solar-technology platform leader at GE's Research facility in Niskayuna, N.Y.
"We think cad tel fundamentally has better cost structure than other thin-film technologies," she said. "The combination of efficiency that we think we can get to, the yield of the manufacturing line, the cost of manufacturing, and the cost of raw materials--the combination gives us the best outcome for making electricity."
Over the past three years, a number of companies have invested in making thin-film solar cells from a combination of copper, indium, gallium, and selenide (CIGS). But CIGS is a tricky material to work with because manufacturers need to control four materials, noted Merfeld. Cadmium and tellurium are byproducts of existing mining processes, such as copper mining.
In terms of efficiency, Merfeld said GE projects it can come to market with a solar panel that is more efficient than what First Solar already offers, which is about 11 percent.
GE expects to target the utility market with its panels, but there is potential for commercial and residential customers as well. Because thin-film panels are less efficient, they are typically used in places where space is not a major constraint.
GE no longer produces panels made from crystalline silicon and plans to enter solar with high-volume manufacturing. "We decided not to step into manufacturing in 2009 as many other companies did because we wanted to make sure to have a competitive advantage from the technology," Merfeld said.
Asked about the toxicity of cadmium, Merfeld said that the material is stable once it is bound with tellurium. But GE does plan to have a recycling program for its panels, as other solar manufacturers do, she said.