Wednesday, September 18th 2019, 5:35 pm - Researchers say the device could potentially harness as much as 0.5 watts per square meter in hot and dry climates where radiative cooling has a stronger effect.
A joint study from the University of California Los Angeles and Stanford University demonstrates a way to generate electricity in the dark by use of a thermoelectric generator device.
In the study published in the journal Joule, researchers explain that the device consists of a black aluminum disk on the surface with a small thermoelectric generator placed at the bottom part.
The device' surface gives off thermal radiation to the atmosphere at night, allowing its surface to become a cooler temperature than the surrounding air in a process known as radiative cooling.
As heat is released unevenly, the bottom part of the device, which contains the generator, still has heat. The excess heat is converted into electricity.
In the paper, lead author of the study, Aaswath Raman, from UCLA's Department of Material Science and Engineering, explains that the device generated up to 25 millawatts of electricity per square meter, which was enough to power a white LED.
In comparison, the New York Times pointed out that a photovoltaic solar panel is able to harness around 200 watts per square meter when it is under direct sunlight.
This means that a solar panel is able to produce approximately 8,000 times more energy than the thermoelectric generator.
In a news release from UCLA, Raman explained that the device could potentially harness as much as 0.5 watts per square meter in hot and dry climates where radiative cooling has a stronger effect.
The team added that they believed that technology can complement existing solar technology as it is able to work during the night.