Google, Big Oil invest $115 million in solar startup

The souring economy hasn’t dissuaded green tech investors from making big bets on renewable energy. On Wednesday, solar power plant builder BrightSource Energy announced it had raised $115 million from a group of investors that include Google.org, the search giant’s philanthropic arm, and oil giants Chevron and BP.

The investment in the Oakland, Calif.-based startup is Google’s (GOOG) second big solar energy play in the past two months. In April, Google.org joined a $130 million round for eSolar, a Pasadena solar power plant company whose chairman is Idealab founder BIll Gross.

BrightSource Energy, started by American-Israeli solar pioneer Arnold Goldman, has contracts to supply California utility PG&E (PCG) with up to 900 megawatts of solar electricity from power plants to be built in the Mojave Desert on the California-Nevada border. BrightSource has developed a new solar technology, dubbed distributed power tower, that focuses fields of sun-tracking mirrors called heliostats on a tower containing a water-filled boiler. The sun’s rays superheat the water and the resulting steam drives an electricity-generating turbine. (Artist rendering of BrightSource’s planned Ivanpah plant above.)

Given that a 500-megawatt solar power plant can cost more than $1 billion to build, $115 million is but a drop in the bucket. But it will allow BrightSource, which previously raised $45 million, to proceed with the development of its technology as it seeks project financing for construction of its first power plants.

And it can’t hurt to have such high-profile backers when you negotiate power purchase agreements with utilities. Besides Google, BP Alternative Energy (BP) and Chevron Technology Ventures (CVX), previous investors participating in the new round include Morgan Stanley (MS), VantagePoint Venture Partners, Draper Fisher Jurvetson and DBL Investors.

Another new BrightSource investor is Norweigan oil and gas behemoth StatoilHydro (STO). Apparently, even Big Oil has seen the light when it comes to hedging its bets with green energy.