Daily Telegraph - 7 Mar 08

Prof. Robert B. Laughlin
Department of Physics
Stanford University, Stanford, CA 94305

(Copied 28 Nov 09)

Nevada Solar Plant Harnessing Desert Sun

By Catherina Elsworth
March 7, 2008

A field of adjustable mirrors covering a barren patch of the Nevada desert is generating power to help fuel the neon lights and hotels of the Las Vegas strip, thanks to a little known type of solar power gaining currency across the US and beyond.

Nevada Solar One lies some 20 miles south of Las Vegas and is one of two prototype plants to utilise the technology that recently opened in the US. It is capable of producing enough electricity to light up 14,000 homes.

Another 10 such plants are in advanced stages of planning in California, Arizona and Nevada, the New York Times reports.

When the sun is strong, the 10 plants will have the potential to generate as much electricity as three nuclear reactors but can be built in a fraction of the time it takes to construct a nuclear facility.

Unlike solar power from photovoltaic panels attached to roofs, the desert mirrors focus the sun's rays on to black pipes containing a synthetic oil which is used to boil water until it becomes steam. The steam is then used to drive a turbine that generates electricity.

Although not new, the technology is suddenly in high demand given the soaring price of fossil fuel, concerns about the environment and recent mandates in several states that require utility companies to obtain more power from renewable sources.

Nevada Solar One, built by a Spanish company, Acciona, contains 182,000 curved mirrors covering nearly a square mile. Each mirror magnifies the sun's rays 70 times and is adjusted by computerised controls to track the sun as it moves across the sky, maximising energy production. The area typically gets 330 days of sunshine a year.

As well as the US plants, eight are being built in Spain, Algeria and Morocco with another nine projects in the pipeline across Europe, Asia and Africa, according to Frederick Morse, an energy consultant and former head of solar energy at the US Energy Department.

Mr. Morse told the New York Times that solar thermal plants could meet much of the soaring energy demands of desert cities such as Phoenix, Las Vegas as well as much of the southwestern United States.

Some experts even believe the powerful desert sunshine in Arizona, New Mexico, California and Nevada has the potential to meet the energy needs of the whole of the US, although this would require costly extensions of transmission infrastructure into remote desert areas.

A system utilising this type of solar thermal power was developed in the 1980s when a series of plants were constructed in California's Mojave desert. But although relatively inexpensive, the low price of natural gas in the 1990s made the plants uneconomic.

The situation has since changed making the plants economically viable. Solar plants also receive a federal tax subsidy. Nevada Solar One is the first major solar thermal project to be built in over 16 years.

Last month, a 280-megawatt solar thermal plant was announced in Phoenix, Arizona, which will be built by another Spanish company, Abengoa, and finished in 2011. It will rank as the largest such project in the world and be capable of storing heat to continue producing power for several hours after the sun sets.

Manufacturers of solar thermal equipment are braced for a surge in demand. A Las Vegas company, Ausra, is building a factory to make mirrors for one type of solar plant, while German company, Schott, announced it is building a factory in Albuquerque that will produce both photovoltaic panels and receivers for solar thermal power plants.