Duke Solar has been selected to build a 1 MW trough ORC power plant for Arizona Public Service (APS).Raleigh, North Carolina – September 20, 2002 [SolarAccess.com] The APS competitive solicitation requested a 1 MW trough ORC plant that operates unattended with automated startup, shutdown and offers remote monitoring capability. The bids were required to offer system capital costs less than a comparable photovoltaic system and have an operation and maintenance cost lower than the wholesale rate for power (~3¢/kWh). At least three companies bid on the project. “The trough system that will be used for this project is an enhanced version of solar parabolic trough used at the SEGS plants in California,” said Gilbert E. Cohen, Duke Solar VP of Engineering & Operations. “It includes the collector structure, the reflector panels , the absorber tube (also called receiver), a control system and a drive system.” The receiver, one of the key elements of the collector, is a stainless steel tube with a special selective coating surrounded by a glass sleeve. The receiver is located at the focal point of the parabolic trough and heats a fluid circulating inside. APS will use the plant to help satisfy their Arizona Environmental Portfolio Standard obligation that requires utilities to generate a portion of their energy from solar resources. The utility believes that small, modular trough plants could provide a lower cost alternative that would help them meet their portfolio requirements within their budget. If cost and performance goals are achieved with the first plant, APS will consider up to an additional 10 MW of systems to be installed over a 10-year period. Duke Solar plans to build a 1MW ORC plant that uses a field of forty of its first generation parabolic trough solar collectors. The APS project could be the first commercial deployment of the new DS1 collector, a next generation parabolic trough collector that is currently under development in partnership with the DOE Concentrated Solar Power program. The DS1 uses a special truss and hub structure that should reduce cost and improve structural stiffness over current concentrator designs. Duke also plans to use the new Solel UVAC receiver that has demonstrated a 20 percent increase in thermal performance and improved reliability in recent field-tests. Duke has partnered with ORMAT to provide a 1MW recuperated ORC power cycle. ORMAT has extensive experience with ORC power cycles in waste heat, geothermal and other solar applications. Current plans call for construction in early 2004.