Skyline Solar has designed a solar concentrator that relies on more sheet metal and less silicon to cut costs.
The Mountain View, Calif.-based start-up on Monday introduced its product, called High Gain Solar (HGS) arrays, and said that it has raised an additional $24.6 million from New Enterprise Associates and other investors. It's one of six companies to get a Department of Energy grant worth $3 million for solar photovoltaics research.
Its arrays, expected to be available later this year, are targeted at commercial customers and utilities looking to generate from about 100 kilowatts to megawatts worth of electricity. The company has a 24-kilowatt demonstration facility at a plant in San Jose, Calif., with the Santa Clara Valley Transportation Authority.
Skyline Solar's concentrator is built around a reflective metal trough that concentrates light onto strips of monocrystalline silicon cells. A tracking system follows the sun over the course of the day so that sunlight bounces onto the cells directly.
By concentrating the light onto these cells, Skyline Solar says it can deliver 10 times more energy per gram of silicon compared with traditional flat solar panels.
Because silicon is an expensive material, there are a number of solar companies using concentrators to squeeze more electricity from solar cells. Skyline Solar CEO Bob MacDonald founded the company after leaving SolFocus, a company that uses more expensive, high-efficiency solar cells and mirrors to concentrate light 500 times.
Skyline Solar's troughs concentrate the light by only a factor of 10 but its arrays use relatively few parts and those parts can be manufactured with existing equipment, such as that for car factories. An air-cooled heat sink is placed behind the solar cells to improve efficiency.
The market for midsize solar arrays is growing, Travis Bradford, solar industry analyst at the Prometheus Institute for Sustainable Development, told Technology Review.
Utility giant Pacific Gas & Electric expects to install 500 megawatts worth of solar power in part through midsize solar installations. Other potential customers include industrial facilities with enough land and good sun.
But it's unclear that Skyline Solar's design will be much cheaper on balance because the tracking and mounting system adds costs and the prices for traditional flat solar panels are dropping, Bradford said.