The glass panels use standard commercial-grade glass sheets with a thin layer of organic dye coating the surface. These dyes absorb light with matching wavelengths then re-emit them into waveguides that lead the light to solar cells attached to the edges of the glass. The process is straightforward and significantly less expensive than manufacturing traditional solar cells. Organic solar concentrators can also be used in conjunction with traditional cells to increase their efficiency to as much as 25%.
Based on research originally performed at the Massachusetts Institute of Technology, the organic solar concentrators work without lenses or mirrors and thus retain a fairly constant temperature without the need for costly cooling elements and can even be directly handled or touched while in operation. Because the light sent to the solar cells at the edges of the glass has already been reduced to the narrow band of wavelengths they were designed to capture and turn into electricity, these cells are also more efficient than similar cells in other configurations (the panel as a whole is less efficient than a standard solar panel, but much cheaper and can be used in a much larger range of conditions). In addition, the lack of moving parts and limited connectors mean these panels require less maintenance than standard photovoltaic arrays.
There isn’t much information available about the dyes used by the panels or the specific process used to apply them to the glass, but Covalent Solar claims to use standard commercial dyes. The key is to use them in the right combinations to match the wavelengths expected by the integrated solar cells. Covalent Solar also uses dyes that absorb light in a different wavelength than they emit so the emitted light isn’t recaptured by the dye, lowering efficiency.
TFOT has previously reported on other innovative photovoltaic systems including a new low cost manufacturing process for copper indium gallium selenide-based solar cells, solar panels based on plant materials instead of the more traditional silicon, and plastic dye-sensitive solar cells with an efficiency close to traditional thin film solar cells. TFOT has also reported on innovative uses of solar panels including the solar panel installed on the roof of 2010 model Toyota Prius cars, the aigo portable solar charger capable of using solar power to recharge some mobile phones, and a solar-powered robotic lawnmower.
Read more about the organic solar concentrator at the Covalent Solar website.