Solar Trough Power Plant Opens in Arizona

Arizona Public Service Company (APS) has announced the opening of the state’s first solar-thermal power plant, and the first built in the nation in 17 years. Built by Solargenix Energy, LLC, of Raleigh, North Carolina, the plant features over 100,000 ft² (9,000 m²) of parabolic-trough mirrors—looking like several rows of mirrored half-pipe—that focus sunlight on pipes filled with mineral oil (see EBN Vol. 13, No. 5). The superheated oil vaporizes a second fluid through heat transfer, and the vapor spins a turbine to generate 1 MW of electricity, enough to power 200 homes. Energy storage capacity allows the fully automated plant to supply the energy when it’s needed. The plant is the first solar trough system to use an organic Rankine cycle power block for generation; this configuration is more typical of geothermal or biomass plants and allows for generation at lower temperatures. Construction of the $6 million plant began in June 2004 and ran for 15 months. Solargenix is currently constructing a 64 MW solar thermal power plant in Boulder City, Nevada, expected to be the largest of its type when finished next year (see EBN Vol. 14, No. 12). Solargenix is online at www.solargenix.com. Read more on Solargenix and solar thermal technology in EBN Vol. 13, No. 5.