Scientists in China recently announced that they are working to develop a solar panel that can harness energy from raindrops.
Researchers from the Ocean University of China (located in Qingdao) announced their findings (A Solar Cell That Is Triggered by Sun and Rain) in a journal published by the German Chemical Society and said they plan to use graphene, which utilizes a thin layer of carbon atoms arranged in a honeycomb, to produce electricity derived from exposing the material to salty rainwater.
“Raindrops would form a layer of positive ions, which are found in the salt of rainwater,” according to an article published this week by news outlet Quartz. “Meanwhile, graphene is rich with delocalized electrons -- which are free to move around. This forms a double layer -- where positive and negative charges are separated -- creating an electric potential between them. The separation in the double layer creates a voltage, just like a battery.”
Graphene has been used throughout the past decade in a variety of scientific applications and it has been previously been proven possible for the material to be used in such a way, according to the report.
A test panel engineered by the scientists at Ocean University was able to generate hundreds of microvolts, which is less power than is produced by a typical AA battery, and the energy conversion rate averaged around 7 percent. The most efficient solar cells currently on the market are able to maintain a conversion rate of 20 percent, by comparison.
The test panel, according to the report, was also tested using water that was far more salinated than typical rainwater, which contains far fewer ions. The researchers said it will take further work to streamline a design for practical application and that, at this point, the project is merely a “proof of concept.”
If, however, researchers and scientists can further refine the technology on which the project is based, they would be moving a step toward creating an all-weather solar cell able to generate energy without the need for constant sunlight.