Light materials: Cadmium telluride

slider_cadmium_telluride

Light materials: Cadmium telluride, a semiconductor that’s good at absorbing light, can be used to make inexpensive solar panels.

GE has confirmed long-standing speculation that it plans to make thin-film solar panels that use a cadmium- and tellurium-based semiconductor to capture light and convert it into electricity. The GE move could put pressure on the only major cadmium-telluride solar-panel maker, Tempe, AZ-based First Solar, which could drive down prices for solar panels.

GE will work to improve upon cadmium-telluride solar panels originally developed by PrimeStar Solar, a spin-off of the Renewable Energy Laboratory in Golden, CO. GE acquired a minority stake in the company in 2007, and then a majority stake in 2008, but it didn’t say much about its intentions for the company until last week, when it announced that it would focus its solar research and development on the startup’s technology. “It definitely makes sense that they would avoid silicon at this stage,” says Sam Jaffe, a senior analyst at IDC Energy Insights in Framingham, MA. Especially in the last year, the market for silicon solar panels has been extremely competitive, with companies making little or no profit. “There’s a lot more space to wring profits out of making cadmium telluride.”

GE appears to be shying away from newer thin-film solar technology based on semiconductors made of copper, indium, gallium, and selenium (CIGS). Merfeld says that it is uncertain how well that material can perform at the larger sizes and volumes needed for commercial solar panels. Cadmium telluride is a simpler material that’s much easier to work with than CIGS, which makes it easier to achieve useful efficiencies in mass-produced solar panels. Merfeld says GE hopes to compete with First Solar by offering higher performance solar cells and reducing the overall cost of solar power. In addition, its name recognition could encourage installers to buy its panels and could help secure financing of solar projects from banks. GE also has extensive distribution networks, especially for new construction, says Travis Bradford, president of the Prometheus Institute for Sustainable Development, a consultancy in Chicago.

Yet challenges remain. Tellurium is a rare material, so to keep its costs down, it will be important for GE to secure large supplies of tellurium rather than buying it on the open market, Jaffe says. He says having another large manufacturer of tellurium-based solar panels may make it necessary to discover new sources of the element. What’s more, First Solar has a large lead on GE in terms of its experience manufacturing cadmium telluride and finding ways to bring down prices. It could be challenging to even get close to First Solar’s costs. “If GE wants to get into photovoltaics, the crystalline silicon boat already sailed,” Bradford says. “The problem is that the thin-film boat may have as well, particularly for cadmium telluride.”

Leave a Reply

Your email address will not be published. Required fields are marked *