Wednesday, 27 January 2010

Solar-driven Stirling engines get to work
January 22, 2010

Business and government officials on Friday cut the ribbon on a solar array in Arizona that uses giant parabolic dishes to generate electricity from the sun. Solar plant developer Tessera Solar installed 60 solar collectors, called the SunCatcher from Stirling Energy Systems, in Peoria, Ariz. Each dish is rated at 25 kWs and the entire facility will have a capacity of 1.5-MWs of generation.

Utilities installing large-scale solar energy generation are typically using arrays of flat photovoltaic panels or concentrating solar energy systems, where mirrors or reflective troughs create heat to make electricity. The Stirling Energy Systems technology also captures heat by using a mirrored parabolic dish that moves to track the sun. But instead of heating a liquid to make steam for a turbine, the heat is directed at a hydrogen gas-filled piston, which drives a Stirling engine to make electricity.

The company claims its technology delivers electricity more efficiently and uses less water than other technologies. Inifinia is another company that has built a solar energyed Stirling engine using a parabolic dish, although it is smaller. Tessera Solar said that it has contracts to install as much as 1,600 MWs' worth of capacity in California and Texas.