Solar Power: Photos of GreenVolts, Sopogy, SkyFuel

Too bad the convention hall in San Diego housing the Solar Power International convention this week has hardly any sun light. If so we’d be able to watch the innovative solar systems that are crowded into the building in action. Interspersed between giant solar panels from some of the major solar gear makers like Sharp, Suntech and Applied Materials, across the show floor, the technology of some of the startups — particularly GreenVolts, Sopogy and SkyFuel — stood out.

If there was a Best of Show award for displays, I’d give it to GreenVolts, which was displaying a system that uses 176 power units that concentrate light onto highly-efficient triple junction cells; called the CarouSol, it tracks the sun on two axis’ and can generate 3 kW. The setup had such a large crowd around it that GreenVolts director of marketing and communication, Michael Goldberg, had to constantly shoo eager attendees away from touching, measuring and taking pictures of it (photo opps for press only!) during a discussion with us.

Unlike GreenVolts, which uses concentrating and photovoltaic technology, Sopogy and SkyFuel use straight solar thermal technology. Sopogy is a Honolulu-based five-year-old company that makes small-scale solar thermal systems, which are condensed versions of the setups that use mirrors and lenses to heat liquid and turn that into power (the photo is of an even smaller prototype). The company has strong roots in the state, with local investors and money from the state legislature to build and operate a solar plant in Hawaii. As of October, Sopogy CEO Darren Kimura told us, the company is working on getting a 1-megawatt solar system up and running to help alleviate Hawaii’s “highest electricity rates in the U.S.”

SkyFuel has been working on dramatically lowering the cost of an established solar-thermal technology that’s been used for decades: trough-shaped solar concentrators. SkyFuel’s innovation is its ReflecTech film material — sort of like mylar but sturdier. SkyFuel developed the material while working with the National Renewable Energy Laboratory (NREL) and the company claims it can bring down the cost of a solar system by 25 percent.