Greentech Media's Top Ten Startups

BrightSource

When BrightSource founder Arnold Goldman pulled an Elwood Blues on his old Luz International team and told them “I’m thinking of putting the band back together” a lot of us were skeptical of another utility-scale CSP company entering the market. To the outsider many of today’s leading solar thermal companies are hard to differentiate. But only BrightSource has the Power Tower, and that made all the difference.

BrightSource brings together over twenty years experience building utility-scale CSP plants, starting with predecessor Luz International’s Solar Energy Generating Systems, which, during the 1980s and 1990s, generated close to 90 percent of the world’s solar power. The company’s DPT 550 system uses flat mirrors, which are less costly than traditional parabolic mirrors, to focus thermal energy on distributed, water-filled towers, creating steam to drive a turbine. BrightSource mirrors track the sun in two dimensions, focusing energy directly onto the PowerTowers, while the choice of water over heating oil improves conversion efficiency.

Flat mirrors allow BrightSource to deploy larger systems at lower relative cost than companies using parabolic arrays. These significant cost reductions were enough to convince PG&E to sign with BrightSource for a potential 900 MW system at a cost of $2 billion to $3 billion. Under the deal, BrightSource will build an initial 100 MW system by 2011, with two 200 MW systems going up in each of the following years. The contract also contains an option for an additional 400 MW system. Though the company has only taken $50 million VC money to date, the PG&E contract is the biggest deal in the history of solar energy.