In 1986 solar panels were literally ripped from the White House roof. But political will and financial incentives have reignited the search for efficient, affordable ways to harness the sun’s energy. Two new solar thermal technologies—which focus sunlight to create heat rather than convert it directly to electricity, as photovoltaics do—promise to make solar power practical at vastly different scales.
The SunCatcher solar thermal system, developed by Tessera Solar and built by Stirling Energy Systems at the Sandia National Laboratories’ National Solar Thermal Test Facility, captures solar energy at 31.25 percent efficiency, the highest ever achieved by this technology. Each of SunCatcher’s 38-foot-wide dishes collects enough heat energy to run a Stirling engine that can then generate 25 kilowatts of electric power. The system will fulfill two of the world’s largest solar contracts, providing a planned 1,600 megawatts to Southern California by 2014. It improved on its predecessor with a ...