Even as the price of clean solar energy continues to plummet, we continue to hear the same complaint over and over again: "Solar power only works when the sun is shining."
But now, scientists at Stanford University have created a revolutionary solar panel that can generate electricity during nighttime hours.
The research, published in the journal Applied Physics Letters in April of 2022, found that through the process of "radiative cooling," existing commercial solar panels could be modified to generate power even in the dark of night.
So how does this radiative cooling work? The solar panels radiate heat toward outer space at night, and this creates a difference in temperature between the panels and the air.
By installing a thermoelectric generator onto the panels, that temperature difference can be harnessed to produce electricity. Basically, these panels can generate electricity thanks to how cold outer space is.
Dr. Shanhui Fan, the electrical engineer who led the research project, explained how nighttime solar panels turn conventional wisdom on its head.
"We tend to think of the sun as the important renewable energy resource," Fan stated in the paper. "[But] the coldness of outer space is also an extremely important renewable energy resource."
While the modified solar panels didn't create a large amount of electricity, — a small fraction of what is yielded during daylight — there could still be immense applications for this technology in the future.
Some examples of these applications could include lighting or electronics and sensor charging.
Currently, the nighttime solar panels aren't able to radically transform the amount of electricity we produce. But as Dr. Fan notes in his research, future iterations of the design could largely improve its efficiency, making it far more viable.
This groundbreaking research underscores how bright the future of clean energy can be — even when the sun isn't shining.
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