Solar-concentrating company Infinia Corporation said Monday it snagged $50 million in a second round of financing for the commercial launch of itssolarsystems that draw on engine technology to convert heat from the sun into electricity.

GLG Partners led the round. Additional backers included Khosla Ventures, Wexford Capital, Vulcan Capital, EQUUS Total Return, Idealab and Power Play Energy.

In total Infinia has raised $59.5 million.

With latest round of funding in tow, the Kennewick, Wash.-based company expects to start manufacturing its solar system technology before the yearend.

The company has developed a large, satellite TV inspired dish covered in mirrors that tracks the sun and focuses the rays of light toward the company's key technology -- a three-foot long cylinder with a 10-inch diameter encapsulating a Stirling engine.

Invented in the early 19th century as an alternative to steam engines, Stirling engines drive a piston using the expansion of gas at a high temperature (click here to see how a Stirling engine works).

In the case of Infinia, the company focuses the sun's rays to heat helium, which then expands and drives the piston. The company has engineered the approach in such a way that the piston moves back and forth. An alternator then captures the power created and converts it into AC power.

The company claims it can deliver renewable energy cheaper than traditional solar technology that uses silicon to convert the sun’s light into electricity.

Infinia has two pilot projects, one at its headquarters and the other at the Sandia National Laboratories in New Mexico.

Infinia is looking for large-scale solar project developers to buy into their approach. And according to the company, future buyers have already expressed more than just interest.

"We have at least a dozen term sheets in play that would represent our first customers," said Gregg Clevenger, chief financial officer for Infinia.

Although Clevenger wouldn't divulge who those customers might be, he did say the potential contacts range in size from 10 megawatts to 150 megawatts of capacity.

Shining Competition

When it comes to providing solar system technology on mass scale, Infinia is far from alone.

Companies like Palo Alto, Calif.-based Ausra, also are in the race. In December, Ausra said it was building the world's largest factory for solar-thermal power systems in Las Vegas (see Ausra to Build World's Largest Solar-Thermal Factory).

Unlike Infinia, Ausra's technology uses fields of mirrors to heat water into steam, which is then converted into electricity using a standard steam turbine.

And others have turned to a type of concentrating solar that takes sunlight from a larger area and uses lenses or glass to direct and concentrate it onto smaller solar cells.

In January, Mountain View, Calif.-based SolFocus installed its first array of solar cells in what will be a 3-megawatt project in Spain. And Germany's Concentrix Solar installed 12 of its solar-tracking systems for a Spanish project, according to Gunther Portfolio.

But despite the slew of companies gunning to deliver concentrating solar technologies, few have been able to deliver the goods on a large scale and at an economical price.

Among the challenges concentrating solar faces are issues of durability because it has more parts than traditional solar systems. For example, Clevenger said each Stirling solar system unit is comprised of several hundred parts.

Infinia plans on contracting with manufacturers around the world to make the individual parts and assemble them in U.S.-based facilities.

But is Infinia's piston-driving approach just one more moving part to worry about? Clevenger said no. "We have developed this engine to be zero maintenance," he said explaining the encapsulating cylinder won't ever have to be opened for such things like adding more lubricant of which there is none.