Next year, southern California will be home to the construction of the largest solar power plant in the world. But unlike the typical flat panels that come to mind, this system won’t use an ounce of silicon. Instead, the 200 year old stirling heat engine will convert 30% of the sun’s power directly into grid ready AC power, much more efficient and cost effective than present photovoltaic cells. Forty foot tall mirrored dishes focus the sun’s energy onto the stirling engine, which uses the 1350°C heat to operate. Unlike combustion engines, the stirling engine has few moving parts, no exhaust, is highly efficient, and runs only on the temperature gradient given to it. Since the vast majority of components are steel and glass, parts are cheap and aren’t affected by the rising cost of semiconductors.
Upon completion in 2010, two plants with a total of 32,000 dishes will produce 800 MW of electricity, enough to power 800,000 homes and keep 3.32 million tons of greenhouse gases out of the atmosphere. This is the first solar installation that will rival the output of a coal plant, which typically produces 1000 MW.
Using a square of the desert 100 miles by 100 miles for these dishes would generate enough energy to power the entire United States (excluding fuel used to run vehicles, which is roughly half the energy consumption of the US). For you politically charged folks out there, the project would cost about one quarter the current price tag of the Iraq war.
by Chris Wegemer