Better & Cheaper Solar Concentrator
Technology Review magazine writes about a new cheaper type of solcar concentrator. Morgan Solar’s high-precision optic–part acrylic and part glass–is molded so that light is trapped and bounces toward its center. A secondary glass optic concentrates the light to 1,000 suns and directs it to a tiny, high-efficiency solar cell. The low-profile design promises to reduce the cost of manufacturing and transportation. Solar concentrators have emerged in recent years as a way to intensify the amount of sunlight hitting solar cells, which are the most expensive part of solar panels. To make solar power more affordable, engineers have sought to use less solar-cell material by concentrating sunlight onto much smaller spaces.
The acrylic component–called a Light-Guide Solar Optic (LSO)–is a new type of solar concentrator that could significantly lower the cost of generating electricity from the sun. Unlike existing designs, there’s no need for mirrors, complex optics, or chemicals to trap and manipulate the light. “It’s pure geometric optics,” says Morgan, director of business development at Toronto-based Morgan Solar.
But this approach has its own challenges. Most concentrators tend to be complex systems that use special lenses, curved mirrors, and other optical components with a “nonzero” focal length. This means that there must be enough distance–an air gap–between the solar cell and the optic to properly focus the light. As a result, concentrator-based systems are usually packaged within bulky enclosures, with enough depth to accommodate the focal length and protect all components during shipping. This means higher material and assembly costs and more expensive shipping.
