Infinia dish turns out solar power with Stirling engine

Infinia on Monday said that it raised $50 million to commercialize a large mirrored dish that turns out three kilowatts of solar power.

With the money, Infinia will be able to bring its Infinia Solar System to market late in 2008.

The company is negotiating with project developers who intend to use hundreds of the dishes in solar power plants in Spain and the southwestern United States, according to Infinia president J.D. Sitton.

The series B round was led by hedge fund GLG Partners and private equity firm Wexford Capital, and included prior investors Vulcan Capital, Khosla Ventures, EQUUS Total Return, Idealab, and Power Play Energy.

The $50 million investment is another large bet on solar electricity, one of the hottest areas in the overall clean-tech business. Many of the larger deals have gone toward developing alternative solar cell manufacturing technology or to finance solar power plants.

Infinia is somewhat unique in its technology approach. Its 21-foot-high dishes concentrate sunlight to make heat, which drives a mechanical power generator. It's based on 19th century Stirling engine design, which uses differences in gas temperature to turn a piston.

Its technology can be used in a wide range of applications, from combined heat and power appliances to residential solar power dishes. But the company chose to focus on small- to medium-scale solar power plant developers because of market demand, said Sitton.

He said that its Stirling engine dish can generate electricity 20 percent to 30 percent cheaper than traditional photovoltaic panels.

Solar power plant developers are also investing in solar troughs or towers, which also use heat to make electricity. Another approach is concentrated solar photovoltaics, where light is amplified onto high-efficiency solar cells to make electricity. Stirling Energy Systems has been contracted to build a facility that uses arrays of very large dishes.

"We think various technologies will migrate to their places in the world where their performance is the best and where they have the lowest cost and best risk profile," Sitton said. "The way we win is by dramatically expanding the number of sites available."

The dishes can be set up on hillsides or even within urban areas, where construction of transmission lines wouldn't be necessary, he said. Because it's a modular design--334 units generate a megawatt of power--power plant developers can incrementally construct a, say, 10-megawatt facility.

The company does not intend to build a separate plant but will instead contract with existing manufacturers which already supply auto parts and other industries.