Solar-thermal technology

The other kind of solar power

Energy: Think of solar power, and you probably think of photovoltaic panels. But there is another way to make electricity from sunlight, which arguably has even brighter prospects

Jun 4th 2009 | from the print edition

AP

IN THE past few months BrightSource Energy, based in California, has signed the world’s two largest deals to build new solar-power capacity. The company will soon begin constructing the first in a series of 14 solar-power plants that will collectively supply more than 2.6 gigawatts (GW) of electricity—enough to serve about 1.8m homes. But to accomplish this feat BrightSource will not use photovoltaic cells, which generate electricity directly from sunlight and currently constitute the most common form of solar power. Instead, the company specialises in “concentrating solar-thermal technology” in which mirrors concentrate sunlight to produce heat. That heat is then used to create steam, which in turn drives a turbine to generate electricity.