Researchers at Michigan State University have created a fully transparent solar concentrator, which could turn any window or sheet of glass into a photovoltaic solar cell.
According to Richard Lunt, who led the research, the team is confident that the transparent solar panels can be efficiently deployed in a wide range of settings, from “tall buildings with lots of windows or any kind of mobile device that demands high aesthetic quality like a phone or e-reader.”
Past “transparent” solar panels were really only partially transparent, due to the fact that if fully transparent, light would pass through the medium and therefore could not absorb the sunlight.
To get around this limitation, the Michigan State researchers use a slightly different technique for gathering sunlight. Instead of trying to create a transparent photovoltaic cell, they use a transparent luminescent solar concentrator (TLSC). The TLSC consists of organic salts that absorb specific non-visible wavelengths of ultraviolet and infrared light, which they then luminesce (glow) as another wavelength of infrared light (also non-visible). This emitted infrared light is guided to the edge of plastic, where thin strips of conventional photovoltaic solar cell convert it into electricity.
Michigan’s TLSC currently only has an efficiency of around 1%, but they think 5% should be possible. This may not sound huge on their own, but on a larger scale – every window in a house or office block – the numbers quickly add up.