Did you know that you can have the best of both worlds? Solar energy and a view. A team of researchers as Michigan State University (MSU) have done just this- developed a new type of solar concentrator that when placed over a window, creates energy but doesn’t block the view. It is called a transparent luminescent solar concentrator and can be used on buildings, cell phones and any other device that has a clear surface.
While research in this arena is not new, the results were poor as the energy production was low and inefficient and the materials were colored thereby blocking the view below the solar cell. The MSU solar harvesting system uses small organic molecules developed by Lunt and his team to absorb specific nonvisible wavelengths of sunlight better than its predecessors.
“No one wants to sit behind colored glass,” said Lunt, an assistant professor of chemical engineering and materials science. “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. We can tune these materials to pick up just the ultraviolet and the near infrared wavelengths that then ‘glow’ at another wavelength in the infrared.”
The “glowing” infrared light is guided to the edge of the plastic where it is converted to electricity by thin strips of photovoltaic solar cells. “Because the materials do not absorb or emit light in the visible spectrum, they look exceptionally transparent to the human eye,” Lunt said.
One of the benefits of this new development is its flexibility. While the technology is at an early stage, it has the potential to be scaled to commercial or industrial applications with an affordable cost. Lunt noted that more work is needed in order to improve its energy-producing efficiency. Currently it is able to produce a solar conversion efficiency close to 1 percent, but noted they aim to reach efficiencies beyond 5 percent when fully optimized. The best colored LSC has an efficiency of around 7 percent.