Surprises in the Desert
Deserts have long been imagined as hot and desolate landscapes—but their reputations have been burnished recently. Deserts are now more likely to be appreciated as unique and often surprisingly diverse environments. Approximately 40 miles southeast of Las Vegas, the desert does indeed hold a most surprising find—a power plant generating electricity from the sun.
When most people think of solar energy, images of photovoltaic panels on rooftops come to mind. But there is another kind: concentrated solar power, which uses mirrors to collect and transform the heat of the sun into steam, which spins a generator. CSP’s relatively simple approach enables it to produce renewable electricity on a scale comparable to conventional coal and natural gas plants.
The third-largest solar power plant in the world—and the largest CSP plant in the United States—was built outside Boulder City, Nevada, in June 2007. The Nevada Solar One plant uses 760 long, tubular mirrors (or parabolic troughs) to concentrate the sun’s energy on solar receivers. The receivers heat a mineral oil fluid to 734 degrees F, which turns water into steam, which powers a turbine to generate electricity. The solar receivers track the sun’s movement, allowing the facility to produce electricity during all the hours the sun is brightest.
The solar fields themselves occupy an area roughly the size of 200 football fields. The plant’s maximum capacity is 75 megawatts, and it generates about 134 million kilowatt-hours of electricity each year—enough to power the lights, appliances, and electronics in 14,000 average U.S. homes. This near-zero-carbon electricity reduces global warming emissions by an amount equivalent to taking 20,000 cars off the road each year.
CSP is now sparking a lot of attention. Interest is especially high in the desert Southwest, which contains large open spaces and some of the world’s best solar resources. This area is also close to some of the country’s largest and fastest-growing population centers. As of July 2008, the federal Bureau of Land Management had received 125 applications to develop large-scale solar facilities on public lands (EIA 2008). In California alone, developers have proposed more than 3,500 megawatts of CSP projects, which are now under regulatory review (CEC 2008a).
Another piece of good news is that the construction of CSP plants creates good jobs. Estimates suggest that every 100 megawatts of installed CSP capacity creates 455 temporary construction jobs (Stoddard, Abiecunas, and O’Connell 2006). The Nevada One facility, for example, provided over 800 construction jobs for about 17 months, and now permanently employs approximately 30 people (ACCIONA 2009).
As with any renewable energy technology, CSP must be built in an environmentally responsible manner. Because many CSP projects are sited in desert areas, developers must avoid disrupting the natural habitats of unique desert plants and animals, and minimize the water used for cooling. But if careful policies guide environmentally responsible CSP development, our deserts may continue to be surprising places—where catclaw acacia and solar power plants alike delight the occasional visitor.
ACCIONA. 2009. Nevada Solar One. Accessed on April 29, 2009.
California Energy Commission (CEC). 2008a. Large solar energy projects: Solar thermal projects under review or announced. Sacramento, CA. Accessed on August 25, 2008.
Energy Information Administration (EIA). 2008f. Solar thermal collector manufacturing activities 2007. Washington, DC: U.S. Department of Energy.
Stoddard, L., J. Abiecunas, and R. O’Connell. 2006. Economic, energy, and environmental benefits of concentrating solar power in California. NREL/SR-550-39291. Golden, CO: National Renewable Energy Laboratory.