This device can use temperature difference to generate electricity at night, and can be used as a supplement to solar energy and energy storage

　　It is understood that there are still more than 1.7 billion people in the world without a reliable power supply. At present, many areas without electricity have begun to use solar energy to generate electricity, and the energy storage system has played a certain guarantee for the power supply at night.

　　But just generating electricity during the day is not enough. Researchers at Stanford University and UCLA are working on a technology that can generate electricity at night.

　　The technology itself is not very new, in fact, its principle comes from nearly 200 years ago.

　　This device is called the Thermoelectric Generator. Through the Seebeck Effect, the temperature difference between two metal plates is used to generate electricity. The greater the temperature difference, the greater the power generated.

　　The researchers built a device that consists of two "plates" stacked on top of each other. The top plate faces the cold air of the night sky, while the bottom plate faces the ground and is enclosed in relatively warm air. There will be a temperature difference between the two plates.

　　At two different temperatures, the device begins to use the flow of heat to generate electricity. But under such a small temperature difference, the power that can be generated is limited. The researcher's equipment only generates 25 milliwatts per square meter of electricity, which can satisfy a small LED reading light. In contrast, a solar cell of the same size has 4000 times the power.

　　The device itself can also be improved. For example, use in drier climates, apply coatings to equipment, create greater temperature differences, and so on. The upgrade of these technologies can increase the power output by 10 times.

　　This technology can provide another viable energy source for areas without electricity or where electricity is expensive. Of course, it is unlikely to replace the status of solar power generation and energy storage batteries. After all, even the expensive lithium iron phosphate batteries are now terribly cheap.