When completed in 2008, the 5-MW Kimberlina concentrating solar power (CSP) plant became the first large-scale solar thermal project to come online in California in 20 years.

Since then a range of projects have been approved, started construction or been completed, spawning a new boom in CSP. But the Kimberlina plant is different: While developers have typically chosen parabolic troughs or power towers in the past, this project utilizes Compact Linear Fresnel Reflectors, or CLFR, a newer technology starting to gain ground.

A CLFR power plant uses flat mirrors to focus sunlight onto a central receiver tube and directly create superheated steam. Rather than use molten salt or oil as a working fluid, the technology simply uses water. A CLFR project is generally less expensive to build because it uses fewer receiver tubes, less land and less expensive mirrors than, say, parabolic toughs. (The 5-MW Kimberlina plant cost about $3 per watt to build – larger CLFR plants could be $2.50 per watt, about 20% less expensive than trough technology).

However, CLFR has not historically been the first choice of developers. The technology's most mature competitor, parabolic troughs, have been in operation for more than 20 years. Because CLFR is still somewhat new, investors have been less willing to back it.

But that's changing. The French energy company AREVA recently took over Kimberlina's developer, Ausra, bringing institutional credibility and a very strong performance guarantee. With more than 1,000 MW in the pipeline, and with the 5-MW Bakersfield project in operation for almost two years now, the company is building a track record that may make investors more comfortable.

See for yourself how CLFR operates: In the video below, David Wagman of Power Engineering Magazine takes us on a tour of the Kimberlina plant with AREVA Solar's Bill Conlan.