Yet another renewable energy technology-concentrating solar power (CSP)-may be ready for the explosive growth that has marked solar photovoltaic and wind power systems in recent years.

CSP, a utility-scale technology ideally suited to desert areas, is resurging around the world, with major facilities being built or planned in the U.S. Southwest, Spain, North Africa, Peru, Chile, and even Germany, write Susan Moran and J. Thomas McKinnon in the March/April issue of World Watch magazine. In the United States, a "perfect storm" of influences-especially growing public concern about coal, new venture
capital, high oil prices, and state renewable energy mandates-is positioning CSP to become a much bigger part of the energy mix.

CSP delivers power in the middle of the day, when demand is typically highest. And CSP facilities can be equipped with thermal storage capacity that enables them to supply "off-peak" power long after the sun has gone down. Costs are currently around 17 cents per kilowatthour (kWh), but Moran and McKinnon cite one set of projections suggesting that cost could drop to 8 cents/kWh with experience. Department of
Energy research grants have been awarded to nine U.S. companies in an effort to bring costs down to 7 cents/kWh by 2020.

Although Congress failed to extend a solar investment tax credit earlier this year, many U.S. states are more sympathetic. In California, for instance, several utilities have signed power purchase agreements with builders of CSP facilities.