Top and above: New technology that harnesses the mechanical energy of falling raindrops might make give renewable-energy fans something to smile about. Images credit: Shutterstock.
What is it? Researchers at Soochow University in China have developed a lightweight solar panel that generates electricity from rain.
Why does it matter? Solar power is an abundant and renewable source of energy that’s gaining in popularity worldwide, but it’s got a downside: Eventually the sun sets or retreats behind the clouds. While some clever souls are finding ways to store solar energy for later use, Baoquan Sun and his team are approaching the conundrum from a different angle: harnessing the mechanical energy of falling raindrops. They’re not the first scientists to take a crack at this — riboelectric nanogenerators(Tengs) have been in the mix for a while — but they say their invention’s simplicity and efficiency set it apart, as does its weight. “In future, we are exploring integrating these into mobile and flexible devices, such as electronic clothes,” Sun told The Guardian.
How does it work? The team outfitted the top of a photovoltaic cell with two transparent polymer layers. As a raindrop falls on the device and rolls off, it creates an electrostatic charge. “Our device can always generate electricity in any daytime weather,” Sun said. “In addition, this device even provides electricity at night if there is rain.” More details appear in the team’s paper, published in ACS Nano.