Los Angeles Times - 29 Mar 09

Prof. Robert B. Laughlin
Department of Physics
Stanford University, Stanford, CA 94305

http://articles.latimes.com/2009/may/29/business/fi-rocketdyne-solar29
(Copied 5 Dec 09)


A Solar Plant That's Worth its Salt

The mineral is a key part of a Santa Monica firm's proposed alternative energy project in the desert. The technology was proved workable in a pilot project near Barstow in the 1990s.

By Peter Pae
May 29, 2009

Just past Barstow on Interstate 15, Las Vegas-bound travelers can eye a tower resembling a lighthouse rising out of the desert encircled by more than 1,800 mirrors the size of billboards.

The complex is often mistaken for a science fiction movie set, but it is actually a power plant that once used molten salt, water and the sun's heat to produce electricity.

Now a storied rocket maker in Canoga Park and a renewable energy company in Santa Monica are hoping to take what they learned at the long-closed desert facility to build a much larger plant that could power 100,000 homes -- all from a mix of sun, salt and rocket science once believed too futuristic to succeed.

The Santa Monica-based energy firm SolarReserve has licensed the technology, developed by engineers at Rocketdyne.

"Molten salt is the secret sauce," said SolarReserve President Terry Murphy.

It is one of at least 80 large solar projects on the drawing board in California, but the molten salt technology is considered one of the more unusual and -- to some energy analysts -- one of the more promising in the latest rush to build clean electricity generation.

"It's actually something we'll likely see in a few years," said Nathaniel Bullard, a solar energy analyst with New Energy Finance in Alexandria, Va. "It's moving along in a nice way, and they have good capital behind it."

SolarReserve, which is financing and marketing the project, said it is working on agreements with several utilities to buy electricity generated from the plant. It hopes to have several announcements in a few months that could help jump-start construction of the first plant, which would probably be on private land in the Southwest, Murphy said.

The company last fall secured $140 million in venture capital.

The plant could begin operating by early 2013. It would use an array of 15,000 heliostats, or large tilting mirrors about 25 feet wide, to direct sunlight to a solar collector atop a 600-foot-tall tower -- somewhat like a lighthouse in reverse.

The mirrors would heat up molten salt flowing through the receiver to more than 1,000 degrees, hot enough to turn water into powerful steam in a device called a heat exchanger. The steam, like that coming out of a nozzle of a boiling tea kettle, would drive a turbine to create electricity.