After more than a decade of innovative engineering and validation testing Stirling Energy Systems (SES) and Tessera Sol have presented four newly designed solar power dishes .These four new dishes are the follow-up model of the original SunCatcher system and will be ready for commercial production in 2010.
The six first-generation SunCatchers are currently planted in the New Mexico desert where they are producing up to 150 KW of grid-ready electrical power during the day. The new dishes have been upgraded and tested a Sandia National Laboraratories to allow for a high rate of roduction and cost reduction. Sandia’s concentrating solar-thermal power (CSP) team has been working closely with SES over the past five years to improve the system design and operation which uses a Stirling engine.
The modular CSP SunCatcher uses precision mirrors attached to a parabolic dish to focus the sun’s rays onto a receiver, which transmits the heat to a Stirling engine. The engine is a sealed system filled with hydrogen. As the gas heats and cools, its pressure rises and falls. The change in pressure drives the piston inside the engine, producing mechanical power, which in turn drives a generator and makes electricity.
The new SunCatcher is about 5,000 pounds lighter than the original, is round instead of rectangular to allow for more efficient use of steel, has improved optics, and consists of 60 percent fewer engine parts. The revised design also has fewer mirrors — 40 instead of 80. The reflective mirrors are formed into a parabolic shape using stamped sheet metal similar to the hood of a car. The mirrors are made by using automobile manufacturing techniques. The improvements will result in high-volume production, cost reductions, and easier maintenance.
SunCatchers have numerous environmental advantages. They are said to have the lowest water use of any thermal electric generating technology, require minimal grading and trenching and require no excavation for foundations. And more important they will not produce greenhouse gas emissions while converting sunlight into electricity. Tessera Solar is planning to build a 60-unit plant generating 1.5 MW by the end of the year either in Arizona or California. One megawatt powers about 800 homes. The proprietary solar dish technology will then be deployed to develop two of the world’s largest solar generating plants in Southern California with San Diego Gas & Electric in the Imperial Valley and Southern California Edison in the Mojave Desert, in addition to the recently announced project with CPS Energy in West Texas. The projects are expected to produce 1,000 MW by the end of 2012.