Indeed, a team of researchers was able to generate enough electricity to power the LED lamp using equipment worth $ 30; thanks to the so-called radiative cooling.
According to an article published by the researchers, 1.3 billion people do not have access to electricity, and that the batteries, which produce electricity at night from solar panels; may be expensive costs, which made them devise a way to generate electricity at night.
Solar panels usually generate electricity from the sun through a physical process called the photoelectric effect; others work through thermal processes, in which the sun is hotter and the Earth is cooler, and this temperature difference can turn into usable energy.
The mission of the researchers came. The researchers' creation consists of a 20 cm (8 inch) black-plated aluminum disc that is connected to thermal generators. These discs are radiation emitters and are usually cooler by several degrees of ambient air.
The process is through the flow of heat from the ground to the air, and then from the air through thermal generators, and then to the disk that radiates heat up.
The device had been tested in California and was able to generate 25 milliwatts per square meter of disk, enough to run a small LED lamp during the day.
The device can also work in the opposite direction, absorbing sunlight and producing electricity from heat transmitted from the sun to the disk and in the external environment.