Dishing Out Real Power
Costs are down, interest is up, and the Stirling solar system is ready to flick the switch
The way Robert Liden sees it, his company is simply building an odd-looking car. It’s made mostly of steel and glass, after all, and it has an engine with a radiator and a water pump. It just doesn’t have wheels, s
eats or a Blaupunkt.What it does have is a generator that can power up to eight homes. No, the device isn’t a car; it’s a Stirling solar dish, and Sandia National Laboratories in Albuquerque, New Mexico, has recently completed a mini power plant composed of six of Liden’s dishes.
The dish, made by Stirling Energy Systems in Phoenix, is the world’s most efficient solar generator. It uses an old principle—that concentrated light is a great heat source—to achieve a level of efficiency on par with conventional power sources and far higher than traditional solar cells. Instead of converting sunlight directly into electricity, as those familiar rooftop solar panels do, it uses a concave array of mirrors to focus light on a central point, where the resulting heat causes compressed hydrogen to expand, driving a four-cylinder engine that turns a 25-kilowatt generator.
