Solar power has the potential to generate about 40 percent of America’s energy, yet the technology still has limitations. One is weather. Clouds and rain diminish solar cell efficiency, a problem for places that are more overcast than sunny. But new research could change that. A team of four Chinese scientists from Yunnan Normal University and the Ocean University of China recently discovered how applying graphene to solar panels turns rain into clean energy.
What if rain could power solar cells as well as sun? That’s the question the Chinese scientists sought to solve, and it turns out using graphene provides the answer. The process of extracting this one-atom thick layer of carbon from graphite was only discovered a little over a decade ago by researchers at The University of Manchester, who won a Nobel Prize in Physics for their discovery. This thin material is changing the way we live – with applications in everything from water purification to wearable technology. It’s also “the world’s most conductive material,” which makes it perfect for solar cells.
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The Chinese scientists placed graphene on top of solar cells, which, in the presence of rainwater, makes all the difference. The positively charged ions of different salts present in rain, such as ammonium, calcium, and sodium interact with graphene’s electrons to produce electricity, allowing the solar cells to function on even the dreariest of days.
It’s an exciting step, but not a final solution. The graphene-coated solar cells aren’t very efficient yet; they are only able to transform 6.5 percent of the energy generated into electricity. Most solar panels are able to convert around 22 percent, so more research is necessary. Still, we are only beginning to tap into graphene’s potential, and further development could have profound implications for the future of solar.
Images via Jon Olav Eikenese and Wikimedia Commons (1,2)