Stirling Engines (Could) Rule
The first Stirling engine was created almost two centuries ago, but up ‘til now, they’ve mostly just been used as playthings. But for the past two decades, the U.S. Department of Energy has been trying to figure out how to make these things really work, and in serious ways.
Here’s the deal: Stirling engines make solar power far, far more efficiently than photovoltaic solar cells can. A Stirling solar dish--which behaves like a sunflower, following the sun all day and returning to a face-down position at night--directly converts solar heat into mechanical energy, which in turn turns an AC electrical generator. So, large farms of Stirling solar dishes (we’re talkin’ like 20k-dish farms here) could actually deliver cheap solar electricity—maybe even as cheap as we pay for electricity today...Stirling Energy Systems, makers of said dishes, is already in a contract with the DOE. By the end of 2005, they plan to have six dishes connected into a miniature power station capable of supplying enough electricity to power about 40 homes. By 2006, a power plant could transform the combined output of the dishes for distribution of industrial-level power. From 2007 to 2010, the program proposes mass-producing dishes to create a 20,000-dish farm from its own substation that would be directly connected to the grid. By 2011, Stirling solar-dish farms could be delivering electricity to the grid at costs comparable to traditional electricity sources. (Keep your fingers crossed.)
Some people, like Mr. Gizmodo, think that Stirling engines could even be (perhaps for the better) used as portable power. As he puts it:
Now, this could mean clean energy for homes and businesses, which is great, but I'm more interested in portable solar-powered Stirling generators. Like, backpack-sized. You listening, Voltaic? Stirling solar collection dishes could be a hot fashion accessory.