The World’s Largest Solar CPV Farm, Courtesy of Amonix

A Kleiner Perkins-backed startup is supplying the gear for the largest solar farm in the world that will use concentrating photovoltaics — a hybrid tech that uses solar cells and solar thermal tech. Utility Public Service Co., part of Xcel Energy, has agreed to buy power from a 30-megawatt (AC) project being developed by Cogentrix Energy and using CPV gear from Amonix.

When it comes to the basket of solar energy technologies to pick from, utilities have largely favored solar panels and large concentrating solar thermal systems that use mirrors and lenses to concentrate the sun’s rays and capture the heat. But concentrating photovoltaics (CPV) — a hybrid of the two? Not so much.

That’s why the 30 MW, which will be built near Alamosa, Colorado, will be the largest in North America, and likely the world. Currently the largest one in operation in the U.S. is a 1MW CPV project just completed by SolFocus this year. SolFocus is also building a 10 MW CPV project in Southern Spain.

Cogentrix will use CPV panels from Amonix, which recently raised $129.4 million from the likes of Kleiner Perkins Caufield & Byers. Cogentrix, part of the Goldman Sachs Group, plans to start construction on 225 acres in the first quarter of 2011 and complete it in the second quarter of 2012. The 20-year contract with Xcel will provide enough power to supply electricity for 6,500 homes.

The project is the second utility contract announcement for Seal Beach, Calif.-based Amonix in recent months. The company has deals to supply its CPV systems to an undisclosed developer for two projects totaling 14 megawatts (DC), which will go to Tucson Electric Power under power purchase agreements.

The private equity funding and project announcements represent a vote of confidence not just for Amonix but CPV in general. While CPV promises to significantly reduce the amount of solar cells need for a solar project, which make up a big part of the cost of a solar energy system, CPV has met with no shortage of skepticism. The tech relies on motorized trackers and direct sunlight (can’t make use of diffuse light), which has made it less attractive for developers and regions with many cloudy days. Plus, the price for solar cells that go into solar panels have fallen by at least 50 percent during the past two years, making solar panels a whole lot more appealing for developers and utilities.

It will take more than a few deals to move CPV out of the world of niche technologies. One of the first high-profile CPV projects hasn’t panned out so far. GreenVolt promised to complete a 2-megawatt project by the end of 2009 and deliver the electricity to Pacific Gas and Electric. In early 2009, the company said the project be would delayed while it re-worked its technology. Shortly after, the company announced that it was replacing its CEO, Bob Cart, and re-directing its attention from project development and focus more on product development. The company has since hired David Gudmundson as its CEO and Uday Bellary as its CFO.

Amonix’s technology uses Fresnel lenses to concentrate the sunlight 500 times onto triple-junction solar cells. Each system, with 53-kilowatt (AC) of generation capacity, is made up of 7 giant modules mounted on a dual-axis tracker. Each module measures 10-ft. by 49-ft and contains 36 sets of lenses and receivers; each receiver contains 30 solar cells. Carla Pihowich, senior director of marketing at Amonix, told me in June that the company is using cells with 39 percent efficiency, which leads to 31 percent efficiency for each module and 25 percent efficiency overall for each system.

Cutting the costs of building and operating those giant systems remain a significant hurdle for CPV technology developers. Both Amonix and SolFocus hope to do so in part by scaling up their manufacturing. Last month, Amonix said it had secured a lease for a 214,000 square-foot space in North Las Vegas for a factory that should be in operation at the end of this year. During a factory tour I took in May, Vahid Ghassemian, senior vice president of manufacturing operations, told me that Amonix will be automating some key parts of its production process by the end of the year or early 2011.

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