Coming on the heels of last month's new contract announcement (see related story link below: "World's Largest Solar Project Unveiled") by Stirling for a 20-year power-purchase agreement with Southern California Edison for a 500 MW solar generating station, today's announcement is another substantial step forward for the SES solar technology in the commercial electricity generation field.

In this latest deal, SES and SDG&E have agreed to a 20-year contract to purchase all the output from a 300 MW solar power plant, which will consist of 12,000 Stirling solar dishes on approximately three square miles in the Imperial Valley of Southern California. SDG&E has options on two future phases that could add up to 600 MW of additional solar energy capacity to SDG&E's resource mix. This contract will still have to be approved by the California Public Utilities Commission.

"This large-scale application of SES technology will provide clean, renewable solar energy to SDG&E customers," said Bruce Osborn, CEO of SES. "We believe this is a truly historic moment for the solar energy industry, and we are pleased to be teaming with a progressive and innovative company like SDG&E." Its technology is said to be nearly twice as efficient as any alternative solar technology.

The entire energy conversion process in SES Stirling solar dish technology takes place within a canister the size of an oil barrel; it does not require water and the engine is emission-free. It uses a mirror array to focus the sun's rays on the receiver end of a Stirling engine. The internal side of the receiver heats hydrogen gas, which expands. The pressure created by the expanding gas drives a piston, crank shaft, and a drive shaft assembly, which then turns a small electricity generator.

"SDG&E has pledged to supply 20 percent of its customers' energy needs from renewable resources like solar and wind by 2010," said Edwin A. Guiles, chairman and chief executive officer of SDG&E. "With this purchase, SDG&E continues to demonstrate its commitment to bring more renewable energy to its customers."

The previous major contract for SES was in early August, when the company announced a contract with Southern California Edison for a 4,500-acre solar generating station in Southern California, calling for development of a 500 MW solar project in the Mojave Desert northeast of Los Angeles, with an option to expand to 850 MW. The first 500 MW phase, consisting of a 20,000-dish array, will be constructed over a four-year period.