What if the solar panels worked at night? Just develop devices that work exactly the opposite way to solar panels. This is demonstrated by a study on Acs Photonics
And if the solar panels could generate electricity also of night , without therefore needing light ? It would seem like a paradox. But a team of researchers from the University of California in Davis has just succeeded in the venture. He designed, in fact, a prototype of a solar panel , , that is, that works exactly in the way opposite to a traditional solar panel, which has proven to be able to generate small quantities of energy at night . The study has just been published on the pages of Acs Photonics .
The team of researchers, led by Jeremy Munday , of the Electrical and computer engineering department of the university, has developed a prototype of anti-solar panel capable of generating well overnight 50 watts of power per meter square. To realize, an amount equal to a quarter of that produced during the day by a normal solar panel.
But how does it work? The process is similar to what follows a normal photovoltaic panel , but simply the opposite. According to the properties of physics, a hot object with respect to the surrounding environment radiates heat such as infrared light , while a cell photovoltaic, which is cold compared to Sun absorbs light. In practice, we know that the solar panels are cold when compared to the Sun, which is why they absorb the sunlight , which is then converted into energy. The Space , on the other hand, is very cold and if you have a relatively hot object and point it towards the sky , then it will radiate heat towards Space, such as infrared light , also allowing in this case to generate energy. “The thermal energy from the Sun to Earth is taken during the day from a solar panel, which converts it into electricity”, explains to Inverse Munday. “What the new night device does is very similar, but now the hot body is Earth and Space is the cold body”.
To generate electricity, unlike the photovoltaic cell used in a solar panel, in the new device the researchers used the thermoradiative cell , which generates energy by radiating heat in the surrounding environment. “A normal solar cell generates energy by absorbing light, generating a voltage and current flow ”, Explains the author. “In these new devices, however, light is emitted and the current and voltage go in the opposite direction, but energy is still generated”.
However, much more work will be needed to improve the efficiency of the new device. The first question to be solved now will be which materials to use: if silicon is generally used for traditional panels , excellent material for absorbing light, researchers are trying to understand which material can capture light at an extremely long wavelength. As, the author hypothesizes, some mercury alloys.