Infinia, a solar startup which is using Stirling engines to produce solar power, is looking to raise $25 million in funding, and has closed $6 million.

Infinia’s products look like satellite dishes. But instead of sucking in information, they’re gathering sunlight, concentrating the heat from it, and using it to drive steam engines for power. And right now, the company is trying to pull in $25 million in venture funding.

So far, according to SEC paperwork, the Ogden, Utah, company has raised $6 million of that goal from three unnamed investors. But with all the attention on solar in the past few years, chances are the company will generate enough buzz to fill out its latest funding round.

The federal government has been generous to solar thermal projects, which is the kind of utility-scale work in which Infinia has been involved. This year, VentureBeat reports, the federal government has steered $2 billion to such initiatives.

Earlier this month, Ascent Solar, which makes solar panels, attracted $450 million from a Chinese and Singaporean joint venture, while Sungevity, which installs panels, pulled in $50 million from Citigroup. Infinia has attracted its share of funding from venture capitalists in the past, raising $50 million in 2008 from GLG Partners, Wexford Capital, Vulcan Capital, Khosla Ventures, Equus Total Returns, Idealab, and Power Play.

The Utah company’s solar thermal technology uses a parabolic dish of mirrors to concentrate sunlight to heat and expand helium inside a heat exchanger to cause a piston in an engine to run back and forth. That motion then drives an alternator to produce electricity. This type of technology is generally called a Stirling engine.Stirling engines have long been thought of as a promising technology to build solar farms, but the matchup has yet to become as popular as other types of solar thermal technologies, and at least one company has struggled to get its stirling engines built into a commercial solar project.

California regulators approved two Stirling solar projects using technology from Stirling Energy Systems totaling 1372.5 MW last year, but their developer, Tessera Solar (sister company to Stirling Energy Systems), subsequently sold them to different buyers when it couldn’t line up the financing to build them (Southern California Edison canceled its contract with one of the projects). Since then, one of the new buyers, K Road Power, has planned to use Stirling engines only for a small portion of its project while the second buyer, AES Solar Power, has said it will use solar panels instead. San Diego Gas & Electric told us it canceled the contract to buy power from the AES’s project in spring this year.

Like other solar thermal technology developers, Infinia is marketing its technology as suitable for not just solar electricity generation but also for combined heat-and-power generation. The system harvests the waste heat from electricity generation, and that heat can have a variety of uses, from heating a building to running industrial operations. Solar thermal technology developers such as Abengoa Solar and BrightSource Energy have carried out projects where the steam generated by the sun’s heat is used for cooking, showers and laundry at a federal prison and for extracting oil from wells.

Infinia raised $32 million in debt and options last year, according to another SEC filing, and another $50 million in equity before that. Investors include Equus Total Return, GLG Partners, Khosla Ventures, Bill Gross’s Idealab and Paul Allen’s Vulcan Capital.

But like Stirling Energy Systems, Infinia has seemed to also hit a few bumps in the road. Infinia began laying off employees at its previous headquarters in Washington state a few months back in order to move to Utah. The company’s CEO, Mike Ward, who came on board earlier this year, told a local newspaper, the Tri-CityHerald, that the move was to “accelerate from our R&D roots into a world-class solar generator company with geographically consolidated operations.”

However, Infinia has several installations and new customers in India. Infinia completed the first commercial installation of its technology earlier this year, reported the Tri-City Herald. The city and Infinia broke ground on a 45Kw project last year, but Infinia declined to say whether the project has been completed as planned.  Infinia also has installed a 9 KW system that was built on the rooftop of Belen’s City Hall in New Mexico.

In addition, Infinia recently sold 10 MW of its engines to solar developers in India. The deal in India involves a $30 million loan from the federal Ex-Im Bank to Dalmia Solar Power. Dalmia plans to develop the project and sell the electricity to NTPC Vidyut Vyapar Nigam, a subsidiary of the National Thermal Power Corp.