A Solar Cell That Can Work at Night

Researchers at the University of California, Davis, have come up with a solar cell that can work at night. Well, it might come as a surprise to many, but thanks to these scientists, it’s now true.

The researchers, Jeremy Munday and Tristan Deppe, have designed a unique solar cell that can generate up to 50 W of solar power per square meter under ideal conditions at night. This is about a quarter of what a conventional solar cell can generate during the daytime.

The researchers are currently working on developing prototypes of solar cells that can generate small amounts of power during the nighttime. They are also focusing on increasing the power output and efficiency of these cells.

According to Jeremy Munday, a professor in the Department of Electrical and Computer Engineering at UC Davis, the process is similar to the way a normal cell works but works in reverse. To put it in simple words, an object that is hot as compared to its surroundings will radiate heat as infrared light, whereas a conventional solar cell is cool as compared to the sun, and hence it absorbs light.


Munday points out that the space is extremely cold, and if you have a warm object, it will radiate heat toward it, and people have been using this phenomenon for many years. There has been a lot of interest in the devices that can do this during the daytime lately.

Munday further notes that there is another kind of device called the thermoradiative cells, which can generate power by radiating heat to the surroundings. Researchers have been working on it to generate power from waste heat from engines.

“A regular solar cell generates power by absorbing sunlight, which causes a voltage to appear across the device and for the current to flow. In these new devices, light is instead emitted, and the current and voltage go in the opposite direction, but you still generate power,” says Munday.

The device could work during the day as well if the device is kept away from direct sunlight or is pointed away from the sun. Given the adaptability of the device, it can serve as a viable option to balance the power grid over the day-night cycle.

Recently, according to a paper released by the University of Queensland, a set of researchers set a world record for the conversion of solar energy to electricity using tiny nanoparticles called ‘quantum dots’ which pass electrons between one another and generate electricity when they are exposed to sunlight or solar energy. The team of researchers at the University achieved 16.6% efficiency surpassing the previous world record of 13.4%.

Earlier, Researchers at Purdue University came up with a new thermodynamic formula, which reveals that bifacial cells make the double-sided panels generate 15% to 20% more electricity than the conventional mono facial cells on one-sided solar modules.