Clean solar power may be the future of energy. Transparent solar panels that seem just like normal glass may make that future real.
Researchers at Michigan State University have created a solar panel that resembles typical glass, which can be placed on top of a window to collect solar energy, while still providing an unobstructed view.
Called a transparent luminescent solar concentrator, the panel uses organic molecules made to absorb invisible wavelengths of light, such as ultraviolet and near infrared light. The material moves this unseen light to the edges of the panel, where strips of photovoltaic solar cells pick it up and convert it to electricity.
There have been past attempts at similar tech, but the results that have been produced were not transparent enough or were tinted. "No one wants to sit behind colored glass," said Richard R. Lunt, an assistant professor of chemical engineering and materials science at MSU and part of the panel's creators. "It makes for a very colorful environment, like working in a disco. We take an approach where we actually make the luminescent active layer itself transparent."
Such colorless transparency would allow these solar panels to have a wide variety of uses. There are residential and commercial uses of windows using this technology, or gadgets like mobile phones and tablets with these solar cells embedded in the glass, or electronic signs that charge themselves, or even in cars or other vehicles with such windows.
"It opens a lot of area to deploy solar energy in a non-intrusive way. It can be used on tall buildings with lots of windows or any kind of mobile device that demands high aesthetic quality like a phone or e-reader. Ultimately we want to make solar harvesting surfaces that you do not even know are there," said Lunt.
The current version of the transparent solar cells is about one percent efficient, but the research team aims to increase that beyond five percent. Colored luminescent solar concentrators can get efficiency up to seven percent. Opaque solar cells can have an efficency of 15 percent or more.
An article on the transparent solar cells was written by the researchers, "Light Harvesting: Near-Infrared Harvesting Transparent Luminescent Solar Concentrators," and was the cover story of the July issue of the journal Advanced Optical Materials. The article was authored by Yimu Zhao, Garrett A. Meek, Benjamin G. Levine and Richard R. Lunt.