We all know that we can acquire power out of the Sun. There have been several plans of space – located solar stations that would provide us with inexhaustible solar energy. One of them is even going to become a reality in less than ten years. However, have you heard of getting power from the night sky? This idea sounds unviable, but it has already become a project.
A team of ambitious researchers is working on a device that can produce energy using the cold of space. The electricity that this gadget can make is enough for an LED light.
How does this device function?
The device works thanks to the thermoelectric principle based on the difference between the temperatures of two surfaces. In other words, the gadget creates electricity derived from the temperature difference between ‘the hot side’ and ‘the cold side.’ The produced effect is called ‘radiative cooling.’
‘Radiative cooling’ is something that scientists have known for a long time. Some natural phenomena prove the power of this principle. The scientist Aaswath Raman reminds us of these two phenomena. The first one is the fact that sometimes windows can be covered with frost in the morning even if the temperature during the night were not very low. The other one is that in the past, the ancient Persians were able to create and keep ice in the desert.
Aaswath Raman worked with two other scientists – Wei Li, and Shanhui Fan. They used their knowledge of the thermoelectric law and further developed the idea using the earth as ‘the hot side’ and outer space as ‘the cold side.’
How does the thermoelectric generator look?
The scientists mentioned above used the thermoelectric principle and the ‘radiative cooling’ to make a thermoelectric generator. The device consists of two plates; one of them is facing the ground, the other one – the sky. The one, aimed at the earth, derives heat from it. On top of the one facing upwards, there is a black-painted aluminum disk. It gets the heat from the Earth and emits it into space. At the same time, it cools down the temperature of the plate and makes it below the temperature of the surrounding area.
The first experiments with the thermoelectric generator
The ambitious team of scientists tested the generator in 2017. They noticed that there was a temperature difference of 2 degrees Celsius between the two plates. The generator transferred this temperature difference into enough energy to power an LED light, of course not to its full capacity. The scientists were not completely satisfied with the amount of power they had generated.
The future of the thermoelectric generator
Even though the generator doesn’t produce a lot of energy, it still has big chances to be a useful energy source in the future. First of all, the materials used for the device are very cheap. Then, the generator can operate for a long time without the need to have any batteries recharged.
We hope that in the future, scientists will use the thermoelectric generator in combination with solar panels to provide energy all night and day long.