Solar Thermal Power
Solar thermal power stations concentrate and absorb incoming radiation, generating high-pressure steam to drive steam turbines. Over 350MW of power stations have operated in the Mojave Desert for nearly 20 years, and a construction boom is underway worldwide with multiple collector designs and thermal cycles. Solar thermal power systems deliver energy today at roughly half the cost of photovoltaic (PV) electric power; more important, solar thermal systems are being built with thermal energy storage systems, providing a reliable, dispatchable "baseload" energy source without increasing the cost of generated power. Large-scale thermal energy storage systems are well proven and economical, roughly two orders of magnitude less expensive and significantly more cycle efficient than available systems for storing electrical energy. Ausra's innovative Compact Linear Fresnel solar collector system incorporates new air-stable selective surface materials and new optical geometry to lower materials use and assembly cost per unit area versus previous parabolic trough collectors. Based on the research work of Dr. David Mills and colleagues at Sydney University, the company was initially founded in 2002, and has had prototype collectors in operation in Australia since 2004. Ausra moved to the US in 2007 and has built a strong team out of the electric power industry, including CEO Bob Fishman, previously Calpine's Chief Operating Officer. In May 2008 Ausra will open an automated production facility in Las Vegas, NV in May 2008 capable of producing 700 MW (electric) annually. In November 2007 Ausra and PG&E announced a contract for Ausra to supply PG&E electric power from a 177 MW project in central California, planned to begin operation in 2010. California alone needs more than 15,000 MW of clean electric power by 2020 to meet the existing Renewable Portfolio Standard; solar thermal power will play a major role, as the California utilities have announced they're not going to be building more wind (wind contributes little to peak capacity) and other renewables have limited developable resource. A recent study by David Mills and Rob Morgan considered the seasonal correlation of solar power plant output and California grid energy needs, finding that solar alone can deliver over 90% of California grid energy (with similar findings considering the national US grid). The talk will review some of the solar thermal power systems now planned or in use, and discuss aspects of Ausra's technology and project plans. .