Skyline Solar unwraps low-cost concentrator

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.

(Credit: Skyline Solar)

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.

Skyline Solar concentrates light onto strips of monocrystalline silicon cells (bottom) rather than using traditional flat panels.

(Credit: Skyline Solar)

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.

[Harlan879]

Good article on an interesting technology, except for the last paragraph. *All* photovoltaic systems have mounting and tracking requirements for maximum efficiency, and I can't think of any reason why this system would require higher costs in those areas. The thing this system has that flat panels doesn't is that air-cooled heat sink. If that doesn't work well enough, they're going to be melting an awful lot of expensive solar cells... I think other concentrating technologies use liquid-cooled heat sinks, right?

[USDecliningDollar]

Interesting concept.

In Colorado, for residential solar - most of the mounting is done such that panels are angled for the optimum energy output for the entire year. Not sure about industrial applications.

I think that this concentrating technique is better suited for solar thermal and not for PV this is clearly demonstrated by the fact that the design is somewhat hamstrung by dealing with heat. (PV modules are less efficient at higher temperatures) With this design you basically have your PV modules underneath a magnifying glass, and I recall incinerating a lot of ants with a magnifying glass as a youngster.

How many other solar companies show their efficiency stats in grams of silicon? Typically this is done per unit of area ... which tells me that something is being hidden. I could see where this technique would be useful in areas with less than ideal sunlight ... higher latitudes??? But overall ... it seems as if this is the right application on the wrong (PV) technology.

[Crius72]

"How many other solar companies show their efficiency stats in grams of silicon? "

Actually, many do. Usual numbers these days for conventional flat panels are between 6.5-7g/W.



My blog: http://AmericanSolarEconomy.blogspot.com

[mahurshi]

This is good news.

I really hope one day, all these companies with innovative ideas work together and come up with a solution that is superior to all the individual techologies when they are used seperately. Maybe the government should make an effort and encourage the companies to let such a thing happen. Just imagine the possibilities if you can have a blend of all the best ideas to solve one problem..... :-)

[TrimTechComputers]

WE NEED THIS ...... the world should spend more time developing this type of technology to make the most of the Natural Resources ... THE SUN is the One Thing that we cant mess up.... unless the Human Race figures that one out too!

I say that ALL Government Buildings should be Retro-Fitted with Solar Energy Technology to offset the cost of Power by 20% - 30% to start, That could be a huge savings ... just think about that for a minute...

Now for those that might say 20% - 30% is nothing... think about that the next time you see a Retail Store AD for a "Blow Out Sale" (save 25% on selected items)

Hmmmmm