Michigan University researchers have devised what looks like the world’s first fully transparent solar cell. Think of all of those tall glass buildings; wouldn’t it be nice if all that incoming solar energy was harvested somehow? Likewise, why not let your smartphone charge up a bit while it’s taking a tan. Of course this isn’t a new idea, but previous attempts are rather unattractive because the compromise makes windows too shady or dark. After all, the purpose of a window is to let light in, not make energy. Ideally, you’d want them harness energy as well, complementary. The new system devised at MU is exciting because it offers exactly this: energy generation, with no compromise in visibility.
Image: University of Michigan
Obviously, windows are transparent because they let most of the incoming light through. This eventually bounces off your retina and allows you to see outside or inside. This is why all those solar cells meant to line windows make them look dark and make rooms inside shady. They have to absorb some of those light frequencies. The researchers at MU took an alternate route.
As you can see in these quite impressive photos, their system is fully transparent. That’s because the glass itself is not a solar cell – it’s a transparent luminescent solar concentrator (TLSC). The TLSC is made of organic salts tuned to only absorb ultra-violet and infrared energy, the kind of light frequencies you can’t see. The salt then luminesce at another infrared frequencies that gets picked up by tiny plastic channels that line the edges of the “glass” and direct the infrared rays to tiny conventional solar cells.