TU-TESL

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According to foreign media reports, although solar panels are very effective, one of their main disadvantages is that they only generate energy during the day, so they need to store extra energy for use at night. But now, UCLA engineers have developed a prototype device that works almost the opposite of solar panels, collecting energy from the cold night sky to passively power LED lights. The device works according to the thermoelectric principle, that is, the current is generated by the temperature difference between two surfaces. Finally, the principle can be used to help manufacture the thermoelectric conversion device of the automobile exhaust pipe, to charge the automobile battery, to charge the mobile phone for the camping cooker, and to use the temperature to provide power for the wearable equipment. In addition, the thermoelectric device also uses a strange phenomenon - radiation cooling. The solar thermal energy absorbed by the earth's surface emits long wave radiation to the sky at night. If the weather is clear, breezy and dry at night, the temperature of the earth's surface will quickly cool down, and suddenly fall to a low temperature, which is the so-called "radiation cooling effect". Previous radiation cooling experiments have shown that this effect can cool buildings without using energy. Therefore, UCLA researchers combined the above two principles to build a thermoelectric generator. The device is made of a black coated aluminum plate, wrapped by a polystyrene shell, which is also wrapped with an aluminum coated polyester film, which can make the air inside relatively warm, while the aluminum plate is full of cold ground facing the sky. The thermoelectric module uses the temperature difference between the aluminum plate and the surrounding air to generate power. When connected to a voltage boost converter and a small white LED lamp, it can generate enough energy to make the LED lamp light. The team tested the device overnight on the roof and measured the generator's output power in more than six hours, and found that up to 25 milliwatts of power can be generated per square meter, although the energy is not very large, and the energy generated is much less than the same size of solar cells, but also enough to power an LED lamp. And researchers say it's easy to boost its power to 0.5 watts per square meter. Ideally, the thermoelectric generator can be used with solar panels, so the two systems can collect the surrounding energy day and night. (all pictures in the article are from UCLA official website)