Top Ten Solar

6. BrightSource Energy

In the desert of American Southwest, plans are being drawn up by a host of American and European companies that want to use the sun's heat to generate power. BrightSource Energy has emerged a serious contender. The company was founded in 2006, but it technical team came from Luz International, which built nine solar-thermal power plants in the California's Mojave Desert in the 1980s.

Oakland, Calif.-based BrightSource has convinced the two largest utilities in California – Pacific Gas and Electric Co. and Southern California Edison – that it can build power plants with up to 2.2 gigawatts in capacity and start delivering electricity to them several years from now (see BrightSource Inks 1.3GW SoCal Edison Deal). It also recently reached a land deal to build on private property in Nevada, in addition to its plans to build on public land in California. Construction for al these projects are scheduled to start next year.

The company is pursuing a different technology development than what Luz did. BrightSource is setting out to build a field of mirrors, or heliostats, that would concentrate and direct the sunlight to a central tower for heating up water to generate steam. The steam will then be piped to a turbine next to the tower to generate electricity. The technology is newer and considered less proven than the parabolic trough design that uses curved mirrors to heat fluid-containing pipes in front of them. Aside from proving the concept, BrightSource also is competing with companies that have built small solar-thermal power plants in Europe, including Abengoa Solar and Solar Millennium. Abengoa and Solar Millennium both have deals with utilities in Arizona and Nevada.