Solar powered Sterling engine project, from Sandia [View All]

[phantom power]

"The Stirling engine makes solar power so much more efficiently than photovoltaic solar cells can," said Robert Liden, chief administrative officer at Stirling Energy Systems Inc. (Phoenix). "That's because the Stirling solar dish directly converts solar heat into mechanical energy, which turns an ac electrical generator." The bottom line, he said, "is that large farms of Stirling solar dishes — say, 20,000-dish farms — could deliver cheap solar electricity that rivals what we pay for electricity today."

Under a multiyear Energy Department contract that started in 2004, Stirling Energy Systems will supply Sandia National Laboratories with solar dishes for integration into full-fledged power-generation substations capable of direct connections to the existing U.S. power grid. Right now about 20 EEs, including more than a dozen from Stirling Energy Systems, are working full time at Sandia to create the electrical-control systems to manage these sunshine stations.

By the end of 2005, they plan to have six dishes connected into a miniature power station capable of supplying enough 480-volt three-phase electricity to power about 40 homes (150 kW). The next step, in 2006, is a 40-dish power plant that will transform the combined output of the farm from 480 to 13,000 V, for distribution of industrial-level power to an existing substation. From 2007 to 2010, the program proposes mass-producing dishes to create a 20,000-dish farm supplying 230,000 V of long-haul power from its own substation directly connected to the grid.

If the project succeeds, the DOE predicts that by 2011, Stirling solar-dish farms could be delivering electricity to the grid at costs comparable to traditional electricity sources, thereby reducing the U.S. need for foreign sources of fossil fuels.

Power today costs from about 3 cents to 12 cents per kilowatt-hour, depending upon the customer's location and the time of day. The average is 6.6 cents/kW-hr for the industrial sector in 2004, according to DOE. In contrast, the Stirling solar-powered substations operate only during peak hours (daytime) but at potentially the same or less than the peak rates paid today — or "about 6.5 cents per kilowatt-hour during peak periods," said Liden of Stirling Energy Systems.

(there's another link at the bottom of this story, which is the full article. For some reason, the real link isn't working with the DU posting software)
http://www.gizmodo.com/gadgets/gadgets/solar-powered-stirling-generators-026232.php