A Michigan State University research team has at last made a truly transparent solar panel — a innovation that could soon usher in a world where windows, panes of glass, and even complete buildings could be used to produce solar energy. Until now, solar cells of this kind have been only partly transparent and generally a bit tinted, but these new ones are so transparent that they are almost indistinguishable from a usual pane of glass.
Previous claims toward transparent solar panels have been deceptive, since the very nature of transparent materials means that light must pass through them. Transparent photovoltaic cells are almost impossible, in fact, as solar panels produce energy by changing absorbed photons into electrons. For a material to be completely transparent, light would have to travel uninhibited to the eye which means those photons would have to pass through the material wholly (without being absorbed to produce solar power).
So, to attain a truly transparent solar cell, the Michigan State team made this thing called a transparent luminescent solar concentrator (TLSC), which employs organic salts to absorb wavelengths of, light those are at present unseen to the human eye. Steering clear of the fundamental difficulties of making a transparent photovoltaic cell permitted the scientists to harness the power of infrared and ultraviolet light.
The TLSC projects a luminescent glow that has a converted wavelength of infrared light which is also invisible to the human eye. More traditional (non-transparent) photovoltaic solar cells frame the panel of the main material, and it is these solar cells that transform the concentrated infrared light into electricity.
Versions of previous semi-transparent solar cells that cast light in colored shadows can generally achieve proficiency of about 7%, but Michigan State’s TLSC is projected to attain a top efficiency of 5% with additional testing (presently, the prototype’s efficiency reaches a mere one percent). While numbers like seven and five percent efficiency appear low, houses featuring fully solar windows or buildings made from the organic material could compound that electricity and bring it to a more useful level.
Scientists on the Michigan State team believe their TLSC technology could span from industrial applications to more manageable uses like consumer devices and handheld gadgets. Their main priorities in continuing to develop the technology seem to be power efficiency and maintaining a scalable level of affordability, so that solar power can continue to grow as a major player in the field of renewable energy.