Research into transparent solar panels at Michigan State University has created a solar cell that not only captures energy from sunlight, but is also nearly invisible when placed over glass.

The solar panel — called a transparent luminescent solar concentrator — can be placed on top of a window to collect solar energy while still providing an unobstructed view. Furthermore, it uses organic molecules made to absorb invisible wavelengths of light, such as ultra-violet and near-infra-red 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 technology, but the results produced were not transparent enough.

Richard R Lunt, one of the panel creators, said: “No one wants to sit behind coloured glass. We take an approach where we actually make the luminescent active layer itself transparent.”

The colourless transparency allows the solar panels to have a wide variety of residential and commercial uses, such as charging devices like mobile phones and tablets via cells embedded in the screen glass. Further examples of the panel’s everyday use include powering electronic signs — or even electric windows in vehicles.

The current version of the transparent solar cells is 1% efficient, but the research team aims to increase this beyond 5%. Coloured luminescent solar concentrators can achieve efficiencies up to 7%, while opaque solar cells can have efficiencies of 15% or more.