The bad thing about solar panels is that they are quite useful during the day when the sun is shining, but they are quite useless at night, in the dark. But now, that doesn't have to be the case.
A new solar panel design works even at night, according to an article published by Jeremy Munday, a professor in the UC Davis Department of Electrical and Computer Engineering.
Researchers have designed a new solar cell that can generate up to 50 watts of energy per square meter at night under certain conditions. That's about a quarter of the normal output of a solar panel during the day.
The new panel works like a normal solar cell does, except in reverse. Unlike a photovoltaic cell, a so-called thermoradiative cell generates energy by radiating heat into its surroundings and, when pointed at the night sky, it emits infrared light because it is warmer than outer space.
The new device, called an anti-solar cell, collects this radiation to convert it into electricity in the same way that a conventional solar cell absorbs solar radiation.
"We were thinking, what would happen if we took one of these devices and put it in a warm area and pointed it up at the sky," explains Munday. “A normal solar cell generates energy by absorbing sunlight, which causes a voltage to appear across the device and current to flow. In these new devices, light is emitted and the current and voltage go in the opposite direction, but energy is still generated ”, clarifies the scientist.
"You have to use different materials, but the physics is the same," he adds.
Better yet, the new device can also work during the day if it is protected from direct sunlight or away from the sun. In other words, unlike conventional solar panels, this one can work around the clock, which would overcome a serious limitation inherent in the current generation of photovoltaic cells.
"Because this new type of solar cell could operate 24 hours a day, it is an intriguing option for balancing the power grid during the day-night cycle," says the university.
Written by Daniel T cross. Article in English.