An international journal, Applied Physics Letters, published a paper that established the technology to produce energy directly from the cold of space. According to this, by aiming a semiconductor diode in outer space near absolute zero, it produces energy from the cold, as if a solar panel generates sunlight.
The power generation technology using the cold of space is that it is possible to obtain energy through a temperature difference using a photodiode directed toward space. A hemispherical photodiode located at the center of the device grasps the structure facing the sky through a parabolic mirror. This technique concentrates some of the electricity generated by the negative illumination effect that occurs when heat is radiated to an object and converts it into energy. However, it is impossible to generate electricity only in hot places in a few times at zero degrees. Such a space is an outer space that is almost absolute zero.
Although it is not a practical amount of power generation, the research team has already succeeded in generating 64 NW (1 billionth of a watt) of electricity per m2. In theory, it can produce 4 watts per square meter. If practical, it could be mounted on an artificial satellite or a space probe, and used for auxiliary power when solar power cannot be generated by entering the shadows of the earth and celestial bodies. Related information can be found here .