U.S. Department of Energy

    Solar Cell Companies Aim to Cut Costs by Cutting it Thin

    December 17, 2003

    When it comes to solar cells, thin is in, at least for those made from crystalline silicon. The material cost of crystalline silicon is the most expensive part of these solar cells, and a thinner cell uses less material and is, therefore, cheaper. The trick is to find a way to cut paper-thin slivers of silicon without wasting too much time, energy, or material. And about a year ago, Australia's Origin Energy claimed to have accomplished that trick; last week, Origin took a crucial step forward with that process when it announced it is building a $20 million plant to produce solar modules using its ultra-thin "Sliver" solar cells. Construction of the plant is now underway in Adelaide, South Australia, and Origin expects the modules to be commercially available in January 2004. The company claims the plant will start production with the capability to produce 5 megawatts of solar modules per year, but can be expanded in the future to as much as 25 megawatts per year. According to Origin, its solar cells are less than 70 microns thick and convert 19.5 percent of the solar energy that hits them into electricity. See the Origin Energy press release.

    Researchers at the Fraunhofer Institute for Solar Energy Systems (ISE) in Germany appear to be nipping at the heels of their Australian counterparts. The Fraunhofer ISE researchers claim to have produced a crystalline-silicon solar cell that is only 37 microns thick—nearly half the thickness of the Origin Energy cells—and achieves a slightly better solar energy conversion efficiency: 20.2 percent. They have also developed an inexpensive process to attach electrical connections to the cells. However, unlike their Australian competition, the German researchers say that considerable research will be needed before they can economically manufacture the extremely thin silicon wafers. See the Fraunhofer ISE press release.

    While some companies are developing paper-thin solar cells, others are achieving success by trimming the silicon a little, rather than a lot. In August, Japan's MSK Corporation opened the world's largest solar module production plant, capable of producing enough modules each year to generate 100 megawatts of electricity. The facility can handle crystalline silicon solar cells that are only 200 microns thick, about two-thirds the thickness of typical crystalline silicon cells. See the MSK Corporation press release.