Solar thermal power is back! Solar thermal gets less attention than its sexier cousin — high-tech photovoltaics — but has two big advantages. First, it is much cheaper than PV. Second, it captures energy in a form that is much easier to store — heat — typically with mirrored surfaces that concentrate sunlight onto a receiver that heats a liquid (which is then used to make steam to drive a turbine).
Back in the 1980s, Luz International was the sole commercial developer of U.S. solar thermal electric projects. The company built nine solar plants, totaling 355 MW of capacity, in California’s Mojave desert. Luz filed for bankruptcy in 1991 for a variety of reasons detailed in this Sandia report.
For 15 years, no commercial solar thermal plants had been built until the creation of the Spanish system pictured here. Technology Review has published, as an advertising supplement, one of the longest and most informative pieces I have seen on solar thermal, also called concentrated solar power (CSP).
California utilities are also beginning to contract for new CSP plants — “the resurrection of thermal solar arrays,” as the New York Times puts it. In July, Pacific Gas & Electric announced a plan to buy 550 megawatts of CSP in the Mojave Desert.
If you want to read more about this re-emerging form of solar power, the National Renewable Energy Lab has a website with publications on the technology and potential market.