PORTLAND, Ore. The solar power industry could help put Detroit back to work, according to Sandia National Laboratories and their commercial collaborators who plan to break ground next year on the first commercial Stirling engine-based solar energy collectors. The automotive supply chain can be used to make the collectors.
Based on prototypes at the Sandia National Laboratories' National Solar Thermal Test Facility (NSTTF), the patented SunCatcher solar dishes track the sun with parabolic mirrors that reflect light directly into the Stirling engines' combustion chamber, thereby focusing solar heat into electricity from the attached generator.
"Our engines and mirrors are being manufactured and assembled in the United States by what is essentially the existing automotive supply chain," said Sean Gallagher, a vice president at Tessera Solar and Stirling Energy Systems. "This is something that Detroit knows how to do very well. When we get into volume production, this emerging industry will be put our automobile workers back to work."
Tessera Solar (Houston) is constructing two pilot solar dish farms using collectors manufactured by Stirling Energy Systems (SES, Scottsdale, Calif.). The first is a 1,600-megawatt facility for the San Diego California Gas and Electric Utility scheduled to go online in 2010. The second is a Southern California Edison project for a 1,000-megawatt facility in the Mojave Desert to be launched in 2012. The pilot programs will use multiple 60-disk arrays each generating 1.5 megawatts to power about 800 homes--the largest solar generating plants in Southern California.
The U.S. Energy Department constructed the prototype Stirling solar-dish test farm at Sandia National Laboratories. DoE estimates that an 11-square-mile farm of Stirling solar dish farm coud generate as much electricity as the Hoover Dam. If successful, the solar farms could begin spreading across the Sun Belt to reduce U.S. dependence on our current fossil-fuel based electricity generating infrastructure.
Last year, the SunCatcher dish set a new solar-to-grid system conversion efficiency record compared to other solar concentrators, posting a 31.25 percent net efficiency rate. Since then, SES has trimmed 5,000 pounds and 60 percent of the parts count from the experimental Stirling-engine powered solar dishes. The SES design also is aimed at leveraging retooled Detroit automotive plants to help build components for solar dish farms across the southwest U.S.
Each Suncatcher produces about 15 kilowatts of grid-ready electrical power during a typical sunny day. The collector uses precision mirrors attached to a moveable, parabolic dish that tracks the sun to keep its reflected rays focused on the receiver that directs its the heat into a Stirling engine's combustion chamber.
The hydrogen-filled Stirling engine heats and cools inside the engine, causing its internal pressure to rise and fall, driving its piston which produces mechanical power by rotating a shaft that drives an electrical generator. More than 90 percent of the components are said to be manufactured in the U.S.