U.S. Department of Energy

    Environmental Assessment Issued for 750-Megawatt Solar Two Project

    February 24, 2010

    Photo of an array of large mirrored dishes, each composed of hundreds of facets. Each dish has a metal arm protruding from the center, holding a metal box at the dish's focus.

    Sixty SunCatcher solar dish/Stirling systems were recently installed in Peoria, Arizona, to form the 1.5-megawatt Maricopa Solar project. Enlarge this image.
    Credit: Salt River Project

    The California Energy Commission (CEC) and the Bureau of Land Management (BLM) released on February 12 a joint staff assessment and draft environmental impact statement (EIS) for the Solar Two Project, a 750 megawatt (MW) project to be located in Imperial County, about 100 miles east of San Diego. Stirling Energy Systems (SES) and Tessera Solar propose to build 42,000 dish/Stirling systems, called SunCatchers, on 10 square miles of land in the desert. Dish/Stirling systems employ a sophisticated tracking system to point a dish-shaped array of mirrors at the sun, concentrating the sun's heat on a Stirling heat engine, which converts the heat into electricity. SES and Tessera Solar have some commercial experience, as they launched the 1.5-megawatt Maricopa Solar power plant in Peoria, Arizona, in late January. The facility features 60 SunCatchers. SunCatcher technology was developed in the United States through a public-private partnership with DOE. See the press release from Tessera Solar (PDF 303 KB). Download Adobe Reader.

    For the proposed Solar Two facility, the draft EIS found no significant environmental impacts, other than a significant and unavoidable visual impact. However, SES will have to undertake special measures to protect the desert species, including the flat-tailed horned lizard, which has been proposed for listing as a threatened species. The CEC is accepting comments on the EIS until May 13, while the BLM will accept comments until 90 days after the U.S. Environmental Protection Agency publishes its notice in the Federal Register. The BLM published its notice on February 22. See the CEC press release, pages ES-15 through ES-18 (PDF pages 21-24) of the draft EIS (PDF 7 MB), and the BLM notice in the Federal Register (PDF 49 KB).

    SunCatchers are a form of concentrating solar power (CSP) technology, which generally involves concentrating the sun's heat with some form of mirror, and then converting that heat into electricity. While dish/Stirling systems have been slow to take hold, parabolic trough systems, which use trough-shaped mirrors, have been operating in California since the 1980s, and many more are planned for the state. For example, NextEra Energy Resources, a subsidiary of the FPL Group, signed a contract in October 2009 to sell 250 MW of solar thermal power from its proposed Genesis Solar Energy Project in Riverside County to Pacific Gas and Electric Company. The proposed Genesis site, featuring more than 500,000 parabolic troughs, is one of 14 solar projects identified by the BLM for fast-track consideration to receive permits by the end of 2010. The company intends to break ground in late 2010, with operations beginning about 30 months later. See the press releases from the FPL Group and the BLM.

    NextEra Energy Resources has also applied to the California Energy Commission (CEC) for permits to build its proposed 250-MW Beacon Solar Project, another parabolic trough facility, to be located in eastern Kern County. In November 2009, the CEC started its year-long review of three other proposed parabolic trough plants: the 484-MW Palen project near Palen Dry Lake in Riverside County; the 968-MW Blythe project near Blythe in Riverside County; and the 250 MW Ridgecrest project in the high northern Mojave Desert in northeastern Kern County. When such projects involve the use of federal lands, the CEC works closely with the BLM on their permit reviews. See the CEC press release and the CEC's full list of proposed power projects.