SolarReserve Heats Up With $140M for 5GW of Solar Thermal

Although the sun could be setting on the renewable tax credits, private equity is shining down on solar thermal startup SolarReserve. The Santa Monica, Calif.-based company says it has raised a hefty $140 million in a second round of funding for its utility-scale solar thermal power plant design. Citi Alternative Investments, Sustainable Development Investments and Good Energies led the round and were joined by U.S. Renewables Group, PCG Clean Energy & Technology Fund, Nimes Capital and Credit Suisse.

SolarReserve says it will use the money to advance the development of 5,000 megawatts of utility-scale solar thermal plants all over the world, ranging in size from 30 to 500 megawatts. The company had previously tested its technology with the U.S. Department of Energy, but should the renewable energy tax credits not get renewed, SolarReserve, like other solar startups, will likely look outside the U.S. for development opportunities. The company plans to have its first plant up and running by 2010.

SolarReserve’s technology works on the problem of solar power’s intermittent power-generation ability by storing energy in the form of heat in molten salt. Mirrors, called heliostats, reflect and concentrate sunlight onto a central receiver that uses Rocketdyne’s heat transfer technology, which was originally developed for use in liquid-fuel rockets. The extremely hot salt is then piped through another heat exchanger, making steam that in turn powers traditional steam turbines.

SkyFuel, another solar thermal startup, also uses molten salt to store energy as heat, but collects the sun’s rays using parabolic troughs. Google-backed eSolar and BrightSource both use central power tower constructions like SolarReserve’s.

The stealthy startup had previously been largely mum about its financial and development plans. Founded at the start of this year, the company was spun out of United Technologies Corp.’s Rocketdyne division of aerospace giant Hamilton Sundstrand with funding from U.S. Renewables Group.