A giant leap toward space-based solar power

Pacific Gas & Electric Co. for decades has generated power for its customers by splitting atoms, burning natural gas and capturing the force of falling water. More recently, the San Francisco utility began turning to the sun, wind, boiling geysers and even fermented cow manure to produce electricity.

Now, PG&E wants to turn to outer space.
A Manhattan Beach start-up called Solaren Corp. seeks to launch an array of giant solar power collectors into orbit 23,000 miles above Fresno and beam the energy to Earth. PG&E has signed a contract to buy the power — if Solaren can make the technology work.

The proposal is a potential energy game-changer, supporters say. But, critics dismiss it as pie in the sky.

Four or five rocket launches would be needed to put enough solar collectors into a stationary orbit to produce 200 megawatts of power, about half the output of a modern natural-gas-fired plant. The solar energy would be converted radio waves and beamed to a receiving station in Fresno, leaving unscathed any birds or airplanes that get in the way of the highly diffused beam. There, it would be converted to either alternating or direct electric current and dispatched to customers via high-voltage transmission lines.

Spirnak acknowledges that nothing on this scale has been attempted, but the basic technology is proven. Commercial communications satellites have been powered by solar energy for more than four decades. The satellites use the sun’s power, available 24 hours a day in space, to make electricity. The electricity is turned into radio waves to bounce television, telephone and other signals around the globe.

Experience with larger scale, experimental radio transmissions converted to electrical power is limited, PG&E wrote in the regulatory filing. In 1975, NASA’s Jet Propulsion Laboratory transmitted 34 kilowatts of energy about a mile. Last year, a former JPL scientist, John Mankins, transmitted a small amount of power generated by ground-based solar cells 92 miles between two Hawaiian islands.

“The challenge,” PG&E spokesman Jonathan Marshal says, is “putting enough hardware up in space and doing it economically.”

Los Angeles Times