Transparent solar cells that can convert invisible light wavelengths into renewable energy could supply 40% of the US’ energy demand, a Michigan State University (MSU) engineering team have reported.

In contrast to the robust, opaque solar panels that take up a large amount of space – whether on rooftops or on designated solar farms – the transparent solar cells can be placed on existing surfaces, such as windows, buildings, phones, and any other object with a clear surface.

 Traditional solar panels

Traditional solar panels require large amounts of space. 

‘Highly transparent solar cells represent the wave of the future for new solar cell applications,’ says Richard Lunt, Associate Professor of Chemical Engineering and Materials Science at MSU.

‘We analysed their potential and show that by harvesting only invisible light, these devices can provide a similar electricity generation potential as rooftop solar while providing additional functionality to enhance the efficiency of buildings, automobiles, and mobile electronics.’

 the sun

Solar, or photovoltaic, cells convert the sun’s energy into electricity. Image: Pixabay

Currently, the cells are running at 5% efficiency, says the team, compared to traditional solar panels that have recorded efficiencies between 15-18%. Lunt believes that with further research, the capability of the transparent cells could increase three-fold.

‘That is what we are working towards,’ says Lunt. ‘Traditional solar applications have been actively researched for over five decades, yet we have only been working on these highly transparent solar cells for about five years.’

 apple iphone

The cells can be added to any existing transparent surface, including mobile phones. Image: Max Pixel

While solar panels may be more efficient at converting energy than the group’s transparent cells, Lunt says that the latter can be easily applied to more surfaces and therefore a larger surface area, increasing the overall amount of energy produced by the cells.

‘Ultimately,’ he says, ‘this technology offers a promising route to inexpensive, widespread solar adoption on small and large surfaces that were previously inaccessible.’

Transparent solar cells. Video: Michigan State University

Together, and with further work on its efficiency, the authors of the paper believe that their see-through cells and traditional solar panels could fulfil the US’ energy needs.

‘The complimentary deployment of both technologies could get us close to 100% of our demand if we also improve energy storage,’ Lunt says.