Solar Electric Generating Systems power plant in Kramer Junction, Mojave desert, California, USA. The Solar Electric Generating Systems (SEGS) power plant located in Mojave desert is the largest solar plant in the world. It consists of nine solar fields among three nearby sites (Daggett, Kramer Junction, and Harper Lake) which have a combined power generating capacity of 354 MW. The SEGS uses parabolic trough solar thermal technology which so far has proven to be the most commercially successful type of solar power plant. A long parabolic reflecting trough concentrates sunlight on a tube running above the trough. The tube is filled with thermal oil that becomes hot and is used to heat steam for a standard turbine generator. A complete system consists of many such troughs laid out over a large area. The SEGS is an advantageous peaking facility because it provides the most power during those hours when there is the greatest demand, usually on hot afternoons. To regulate generated power and ensure uninterrupted supply during high demand periods, cloudy days and early evenings, a supplemental natural gas generator is used. April 2007.