Search giant Google said Thursday the company's philanthropic arm doled out $10 million to solar-thermal developer eSolar.

The news is part of a larger announcement touting Google's $25 million commitment toward philanthropy, which includes supporting alternative-vehicle advancements (see Google Leaves Out Clean Diesel, Hydrogen).

The funding also is part of the Renewable Energy Cheaper than Coal initiative, or REC, that Google announced in November. As the name implies, the initiative works to reduce clean-energy prices below those of fossil fuels. Google said it would accomplish such a task by spending "tens of millions" on internal research and development, and "hundreds of millions" in capital planning (see Googling Greentech).

At the time, Google (NSDQ: GOOG) said it was already working with two companies, Pasadena, Calif.-based eSolar and Alameda, Calif.-based wind-to-energy developer Makani Power.

Although Google hinted it had made investments in the companies, Thursday's news clarified the amount that eSolar had closed.

The company is developing solar-thermal power plants, which use the sun's heat instead of its light, to produce electricity. The company's approach calls for a field of mirrors that reflect sunrays toward a water tower of sorts. As the water heats, it turns into steam, which can then be converted into electricity using a turbine (see a tech demonstration by eSolar's former CEO here).

But eSolar isn't alone in its efforts to bring solar-thermal power to the masses.

Over the past year, several pieces of news have come out of the sector, including Ausra scoring $40 million from high-profile venture backers Khosla Ventures and Kleiner Perkins, signing deals with Pacific Gas and Electric Co. and Florida Light and Power and announcing it is building the world's largest solar-thermal manufacturing plant (see Ausra Raises $40M for Concentrating Solar-Thermal, Ausra to Build 177-Megawatt Solar-Thermal Plant and Ausra to Build World's Largest Solar-Thermal Factory).

In eSolar's case, the company claims it can build solar-thermal projects between 25 megawatts and 500 megawatts of capacity, all while staying "competitive" with fossil fuels.