92 sq. miles of solar could power the U.S.A.

The stigma of solar as only one of many solutions needed to satisfy our energy needs may not be true. David Mills, chairman and chief scientific officer of solar company Ausra, recently presented a paper at the International Solar Energy Society conference saying that solar thermal plants could indeed solve all of our energy problems, including nighttime electricity. I know...all our energy problems? Well, I guess it's worth taking a look.

The plants use mirrors arranged in a Fresnel configuration to heat tubes of liquid rather than solar cells that convert the sunlight directly into electricity. The steam produced by the heated liquids power turbines that create electricity. While not a new technique, Mills says the technology will allow liquids to hold heat and produce steam during the night also. The paper calculates that 92 square miles of solar thermal farm could power the entire country.

Despite the optimistic results of their calculations, they warn that a plan like this requires a complete revamping of the current electric infrastructure. The country's AC grid would have to be converted to high voltage DC in order to decrease transmission loss from 50% to around 3% while moving the power from the sunny Southwest to the power-hungry North East. Miles says this would be a huge undertaking that would help move the country from "capital-intensive fossil fuel plants that need to run 24/7" to "electricity created by people's and the economy's daily rhythm," which solar and wind energy follows closely.

In the meantime, Ausra plans to develop a 175-megawatt solar power plant with their solar storage technology, hitting the market mid-2009. We're inclined to think that the proposal is more of a thought experiment, and while it's an exciting one, we don't see the U.S. grid switching to DC...ever. But while the South West's abundant sunshine is certainly a resource to be tapped, I'm pretty sure a more distributed system will be best in the end anyhow,

Big ideas require big changes, right? Maybe rethinking the carbon-biased infrastructure is as important as the sources of our electricity.

Via Green Wombat