Marco DeMiroz says there are probably only around 100,000 out of the roughly five million rooftops in America that are good candidates for Soliant’s solar concentrators.

“But that’s ten gigawatts,” says DeMiroz, a VC at Trinity Ventures who recently became interim CEO. After that, Soliant can expand to southern Europe, India and the Middle East.

Like fellow PV concentrator startups SolFocus and GreenVolts, Soliant is moving into the “’Yeah? Prove it’” stage of corporate existence. Originally named Practical Instruments, the company was founded by scientists from the NASA Jet Propulsion Laboratory in 2005 when greentech was an emerging opportunity and VCs were more open to novel ideas.  

In 2007, the company switched from working on a cheap, low-concentration concentrator to a high-powered, dual-concentrator (it has a Fresnel lens and a proprietary concentrator) that can focus the energy of 500 suns onto a III-V solar cell. In 2008, it received $21 million more in a second round and said it hoped to have a 40-megawatt manufacturing facility by late 2009.

But things haven’t gone completely as planned. Soliant is now looking at a 5 megawatt manufacturing facility in the first half of 2010 with 20 megawatts in 2011. It also swapped CEOs (see Soliant Gets Interim CEO).

The next few months will prove crucial. Soliant says it will erect its first commercial installations in the second half of the year. These will be 100 kilowatt or so systems and serve as a beta site to sell larger 100 to 500 kilowatt systems.

Although concentrators got some of their original momentum from the fact that silicon was in short supply, the idea remains viable, says DeMiroz and others. There’s only so much available real estate on commercial rooftops and concentrators take a lot less room than standard thin film or crystalline systems. The system fits into standard racking systems. Because sunlight is concentrated, you only need half of the number of panels and the labor is cut in half, he said. Solar customers are increasingly going to aim at solar applications tailored to their needs.

“CPV excels when you have limited space,” he said.

Soliant’s system, he added, can also crank out the power. A single panel of Soliant’s concentrators can put out 355 watts at peak, compared to 210 watts for a SunPower panel and 80 for an equivalent First Solar installation. Overall, the system is 21 percent efficient, a few points better than most crystalline panels but way ahead of the 10 percent and below seen in thin films.

The fact that concentrators track the sun also means that they can provide higher and more consistent levels of power through the crucial peak power period of 2:00 p.m. to 6:00 p.m., he argued. Conventional solar cells begin to taper off. The performance of multicrystalline solar cells also doesn’t erode when the panel gets hot, a problem with silicon. Soliant tracks the sun to within a 1 percent accuracy.

Nancy Hartsoch, the VP of Marketing at SolFocus, is naturally upbeat on the future too. She estimates that 10 megawatts of concentrating PV was deployed in 2008 and she predicts 50 megawatts will be deployed in 2009. GreenVolts recently replaced founding CEO Bob Cart and pushed out the installation of a 2-gigawatt system for PG&E to mid-2010 (see GreenVolts Replaces CEO Bob Cart). The first megawatt was supposed to be in by the end of 2008.   

Unlike GreenVolts and SolFocus, Soliant will not try to win large utility scale contracts and just focus on roofs. Why? The system only stands about two feet tall, so it’s ideal for those flat roofs on superstores.

That’s the good argument. The negative? Concentrators add capital costs, and it is unclear whether the higher efficiency and greater power output will ultimately level out the math in their favor. Concentrators also add complexity. Soliant’s tracker might move accurately with the sun, but it’s still operated by a motor that will need to be monitored. Conventional solar panels sit passively for decades, only needing the regular washing.

“CPV is a zero billion-dollar market segment with only a few megawatts deployed, stuck in the middle between the rapidly commodifying silicon solar market and the well-financed high-output concentrated solar thermal market,” writes Eric Wesoff, an analyst with Greentech Media.

A Greentech Media/Prometheus Institute report says that by 2020 CPV may only account for 6 gigawatts of solar power worldwide, small compared to the 170 gigawatts of passive solar power.

But the report also says that there will be 100 gigawatts of tracking solar power. And half of Soliant’s story is in its accurate tracker.

So stay tuned.