The other kind of solar power - (Part 1)

Published in The Economist Technology Quarterly June 6th 2009. I will briefly summarize what the article says.It is a very long article. I am therefore detailing it in parts.

"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.

BrightSource Energy, a California company will soon begin constrtucting 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 specializes in 'concentrating solar-thermal technology' in which mirrors concentrate sunlight to create steam, which in turn drives a turbine to generate electricity. 

Solar-thermal power stations have several advantages over solar-photovoltaic projects. They are typically built on a much larger scale, and historically their costs have been much lower. Compared to other renewable sources of energy, they are probably  best able to match a utility's electrical load, says Nathaniel Bullard of New Energy Finance, a research firm They work best when it is hottest and demand is greatest. And the heat they generate can be stored, so the output of a solar-thermal plant does not fluctuate as wildly as that of a photovoltaic system. Moreover, since they use a turbine to generate electricity from heat, most solar-thermal plants can be easily and inexpensively supplememnted with natural-gas boilers, enabling them to perform as realiably as a fossil-fuel power plant.

According to Mark Methos of America's National Renewable Energy Laboratory, solar-thermal power could in theory generate 11,000GW in Americ's south-west. That is about TEN times America's entire existing power-generation capacity."

.... to be continued in part 2, .....