Trying to concentrate

A new U.S. solar thermal tower is now up and running in Lancaster, Calif. Called the Sierra SunTower, the 5-megawatt system from eSolar uses 24,000 mirrors to concentrate sunlight on two, 160-foot towers. The sun then heats water at the top of the towers, which produces steam that then generates power for Southern California Edison, a local utility company. The project was built on private land designated for heavy industrial use.

Solar thermal projects tend to be cheaper than using solar cells, as mirrors tend to be less expensive than silicon solar cells. eSolar chief executive Bill Gross told journalist Marc Gunther in that eSolar, which is largely backed by Google, is “producing the lowest cost solar electrons in the history of the world.” Gross claims that just 25 square miles of mirrors and towers could power the state of California. Solar thermal plants could be less expensive for consumers, too, as the electricity generated in Lancaster costs less than what the average Californian typically pays.

So far, the plant serves only 4,000 people, though Gross says the company plans to replicate the project across the country and, ultimately, internationally. In February, eSolar announced an agreement with NRG Energy to develop three plants in California and New Mexico that’s to generate up to 465 megawatts of electricity.