Among the many different ways to harness solar power, luminescent solar concentrators (LSC) may be one of our favorites – and now researchers are using that technology to design clear solar cells that could also work as windows.
Historically, LSCs have been large, and have required colored glass – but now material engineers working at Michigan State University believe they’ve found the work-around, as they’ve now designed totally transparent solar concentrators, which could be built into windows without blocking the light and disturbing the view.
“No one wants to sit behind colored glass,” said the lead researcher of the study Richard Lunt in a press release. “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.”
The researchers achieved this by developing a system that diverts wavelengths invisible to the human eye. In particular, the concentrator absorbs light in the ultraviolet and near infrared spectrum and then transmits it in the infrared.
After this, the light is directed to the photovoltaic cells, which generate electricity. Since we are not able to perceive the ultraviolet and infrared wavelengths, the material remains transparent and looks to the human eye like ordinary glass.
While the new technology shows promise, the Michigan State researchers hope to make it more efficient before approaching the market. Currently, their solar concentrator tops out at about 1% solar conversion efficiency, as opposed to some other LSCs, which may top out at closer to 7%. The researchers say that they believe they can get their tech to at least 5%.
Conventional solar panels, for comparison sake, usually range between 15-40% of solar conversion efficiency. The applications of this technology, however, are far more reaching than conventional solar panels, and this is a big part of why the researchers are so excited about their new technology.
As Lunt said, “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.”