An innovative method of collecting solar power could enable smartphone users to boost their batteries by leaving their device in the sun.

Researchers at South Africa’s University of the Free State and Belgium’s Ghent University have developed a working model for glass that shifts non-visible light to a solar panel. Using certain phosphor materials in glass, a pane can let visible light through while redirecting ultraviolet and infrared rays to small solar panels mounted at the sides.

“It can be implemented in the screens of cell phones, where the sun or the ambient light of a room can be used to power the device without affecting its appearance,” Hendrik Swart, senior professor in the physics department at the University of the Free State, said in a statement Wednesday.

If it comes to fruition, it could dramatically reduce the problem of solar power’s inefficiency by making panels far more ubiquitous (though we wouldn’t always know it). Current solar arrays involve placing a large, opaque square in front of the sun. This works fine for roofs, but not for windows. Imagine a skyscraper which, instead of having to draw solar energy from a single roof array is able to draw it from all of its windows.

See-through solar would also have a big impact on personal electronics like smartphones, which at present can’t collect solar power without resorting to unwieldy camping gear or elaborate phone cases.

With transparent solar panels, however, a self-charging smartphone could be well within reach.

The idea could also be used for electric vehicles, shifting light from the windows to edge panels to give a small boost, similar to the Toyota and Sono solar cars. The team is also exploring whether a similar idea could be used for durable plastics, so the panels could replace zinc roofs.

Lucas Erasmus, who is working with Swart on the research, added that the design “concentrates the light from a large area to the small area on the sides where the solar panels are placed; therefore, reducing the number of solar panels needed and in return, reducing the cost.”

Although the researchers admit the research is a long way from market, they also think it could reach consumers within a decade, a prediction which bears some resemblance to other research in this area.

Transparent Solar Panels: The See-Through Breakthrough

A similar idea has been trialed by researchers at University College London. The luminescent solar concentrator, with a rather yellowish hue, was detailed in a 2018 article. Some of the main issues with the current research include how to make the panels clear, how to ensure a high yield rate from light hitting the glass, and how to ensure they’re safe for use in buildings.

Maryland-based SolarWindow, founded in 1998, is another firm that claims to have the answer. It uses an array of ultra-thin wires to transport power away, working with a coating that generates electricity. It claims that its solar-generating windows installed on a 50-storey building could generate 50 times more power and 15 times the environmental benefits than a series of panels placed on the roof.

Other firms are also looking at ways to hide solar panels from everyday life. Tesla has developed a solar roof tile that looks like a regular roof to the untrained eye, removing the thick panels that typically adorn solar-powered houses. Australian architect Ben Berwick has created origami solar blinds that could bounce light into a room while collecting energy. A prototype solar tarp could also solve the rigidity of current panels, enabling users to pack the panel away into a bag when not in use.

The Tesla solar roof. Tesla

A see-through panel, like the one described by Erasmus, could offer even more chances to place panels in gadgets. Rumors from 2014 suggest Apple was exploring ways to put solar panels in the Apple Watch, and more recent reports claimed the company was considering a charging solution that could provide power to iPhones in a similar way to Wifi. Getting a solar panel inside these daily gadgets could save battery woes and improve their environmental credentials.

With the world setting record temperatures in recent years, it may be the ideal time.