This is an excerpt from EERE Network News, a weekly electronic newsletter.

May 12, 2010

DOE Awards $62 Million to 13 Concentrating Solar Power Projects

Photo of two solar towers surrounded by reflectors.

One of the 13 awardees is eSolar, which is investigating the use of molten salt in its modular solar power towers. The company opened its first facility in 2009, employing two modules to generate 5 megawatts of power.
Credit: eSolar

DOE announced on May 7 its selection of 13 concentrating solar power (CSP) projects to receive up to $62 million in funding. This funding will support improvements in CSP systems, components, and thermal energy storage to accelerate the market-readiness of this renewable energy technology. The grantees will seek to improve component and system designs to extend operation to an average of about 18 hours per day, a level of production that would make it possible for these plants to displace traditional coal-burning power plants.

CSP technologies concentrate the sun's energy and capture that energy as heat, which then drives an engine or turbine to produce electrical power. CSP plants can include low-cost energy storage, allowing them to provide electricity even when the sun is not shining. Of the 13 awardees, three will evaluate the feasibility of a complete CSP baseload power system and support the development of prototype systems for field testing. Agengoa Solar, Inc. and eSolar, Inc. will both investigate molten salt as a working fluid with thermal storage capabilities for solar power towers, which use a field of flat mirrors, called heliostats, to concentrate the sun's heat on a central tower. The eSolar project will employ multiple modular towers. Molten salt was tested by DOE at Solar Two, a demonstration solar power tower project that was operated in Southern California in the late 1990's. In addition, Pratt & Whitney Rocketdyne will investigate a novel approach to thermal storage for solar power tower facilities.

The remaining 10 projects will study concepts and devices that could be part of a CSP baseload system. These include a thermal energy storage system based on a phase change from solid to liquid; a sulfur-based energy storage system that uses a chemical reaction to store energy; optimization of heliostat arrays to drive down the up-front costs of solar power tower plants; a modular solar power tower system that can be partially assembled in a factory; large-scale thermal storage for use with solar dishes; next-generation, low-cost reflectors with increased reflectivity and durability; and low-cost approaches to parabolic trough systems, which use long lines of trough-shaped mirrors to concentrate the sun's heat on a tube that carries a heat-transfer fluid. See the DOE press release and the CSP section of DOE's Solar Energy Technologies Web site.