Writing a dissertation really cuts down on available blogging time, but I couldn’t pass up a quick post about this! Headlines abound about a new solar cell breakthrough in efficiency found by a University of New South Wales research group and independently confirmed by the US National Renewable Energy Laboratory (NREL).
There isn’t an official peer-reviewed paper about it yet, unfortunately, so I’m gathering bits of information from various news sources – Science Daily, Yahoo, and Think Progress, for example. Definitely give these a read, but here’s what I can gather. Traditional solar cells use just one material that absorbs light really well only in a narrow range of wavelengths. This wastes all the energy from incoming light with wavelengths below that range (and some from higher wavelengths as well, but that gets into some details not necessary here). This group still uses those traditional materials, but the press releases state that the group uses ‘focused light’ and ‘optical bandpass filters’ to reduce the amount of incoming sunlight that is wasted. My best guess is that the researchers developed a system that filters sunlight of varying wavelengths, reflecting each one to a particular solar cell material that’s optimally tuned to absorb that wavelength of light. This maximizes the amount of light that is absorbed as well as the energy in the light that can be used, increasing efficiency to this incredible 40 percent range.
Solar cells are already market competitive if we account for all the external costs of fossil fuels. But if this new type of cell can be easily commercialized, this will be a huge boost to the renewable energy community and for our society as a whole. Apparently, a company called RayGen Resources assisted with the prototype build and will be interested in its application for high-power photovoltaic towers. Here’s hoping for a more detailed research paper about this soon!