Ausra, one of the early startups insolarthermal, is in talks with three global conglomerates to sell itself, according to Reuters, the latest sign that green is going to be a big company game.

Like many Silicon Valley-funded startups, Ausra came up with a novel idea for harnessing clean power, but has lacked the money, engineering and contracts to fully test it out or take it commercial. The company, which raised over $115 million from firms such as Kleiner, Perkins, wanted to replace the expensive parabolic mirrors at solar thermal power plants with cheaper flat mirrors. At one point, the company theorized--as a way to illustrate the power of solar thermal technology--that it could conceivably harvest all of the electrical power the U.S. would need from a hypothetical plot of desert real estate measuring 92 miles by 92 miles.

Unfortunately, it never got a chance to start testing that out on a large scale. PG&E, Southern California Edison and the other big California utilities awarded their solar thermal contracts to competitors such as BrightSource Energy and Stirling Energy Systems. Speculation – never substantiated – circulated in the solar industry that Ausra's equipment could not provide the same level of power as other competitors. 

In February of this year, the company shifted directions. It largely abandoned its earlier plans to build and operate solar thermal power plants. Instead, it would sell equipment to large companies would would operate the power plants.

Power plants "are way beyond" the capabilities of a startup, said CEO Bob Fishman. Rival eSolar made a similar shift, although it said it would continue to seek out power plant contracts. He also strongly denied that its technology was inferior. In fact, Ausra managed to land two contracts, in Australia and the Middle East, after the change in strategic direction.

"We can get twice as much steam per acre as power tower [BrightSource's technology] and twice as much as trough [Solel, Schott]," he said earlier this year. "We can generate steam cheaper than anyone."

Fishman's comments in many ways underscore a major trend toward conglomerates and consolidation in solar. A few weeks ago, Siemens bought Solel, one of the oldest names in solar thermal, for $418 million. BrightSource Energy, meanwhile, one of the most successful startups, this summer enlisted Bechtel as a strategic partner. Bechtel will build and finance a 440-megawatt power plant in California for BrightSource. Bechtel also became an investor in the power plant. By selling part of a major asset, the deal signified that BrightSource needed help from a big brother to realize its ambitions. (BrightSource also won a contract this summer to provide solar thermal equipment to Chevron, which earlier invested in BrightSource.)

Although not an international conglomerate, First Solar is engaging in a similar strategy. Earlier this year, it bought the rights to develop to solar projects from largely defunct Optisolar for $400 million.

If a sale does go through, wags will also likely note that it is Kleiner's first "successful" exit, successful being up to the beholder. The storied VC firm has not yet participated in the few IPOs or major transactions.

Photo of the Kimberlina solar-thermal plant via Ausra.