What powers these new solar panels that work at night?

It seems counterintuitive, doesn’t it? Solar panels, which get energy from, you know, the sun, that can somehow do that at night when there is no sun? Yup, that’s a thing now.

“The coldness of outer space is also an extremely important renewable energy resource,” said Shanhui Fan, lead researcher on a Stanford project that developed solar panels that work at night. You read that right: These panels literally use the coldness of space to create energy. An object facing the sky at night radiates heat into outer space, thus making it cooler than the air temperature around it. The team was able to modify commercial solar panels to take advantage of this and generate electricity through radiative cooling.

The amount of energy created was far less than what the panels can do with sunlight — they generated 50 milliwatts per square meter, as opposed to the roughly 200 milliwatts per square meter that usually comes from the sun. However, there’s certainly still an application here for low-energy scenarios, like charging smaller devices or keeping sensors running. And since the modifications were made to commercial panels, they could be widely adopted fairly easily.