Solar panels, by definition, are technological devices capable of harnessing solar energy to produce electricity or heat water. A team of researchers from the University of California at Davis, however, claimed to have found a way for the panels to produce energy even after sunset, in the absence of it. Yes, it seems like a paradox, but a professor of electrical engineering and computer science Jeremy Munday is working precisely on the prototype of a so-called “anti-solar” panel.
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Solar panels have been around for decades, but the fact that they need sunlight to produce enough power is a limiting aspect and can be a problem: in many parts of the world, during certain seasons, it becomes difficult. to produce and store energy using panels. That’s why the researchers came up with a new panel, designed to work day and night. The solar panel works exactly the opposite of a traditional solar panel and, under ideal conditions, is capable of generating up to 50 watts of energy per square meter at night, or about a quarter of what conventional photovoltaic technology can produce during the day.
But how does it work? The prototype is based on the properties of physics, according to which an object hot relative to its surroundings radiates heat in the form of infrared light, while a photovoltaic cell – cold compared to the sun – absorbs light.
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The professor says, “ To generate electricity after the sun goes down, we are looking at an alternative photovoltaic concept that uses the earth as a heat source and the night sky as a heat sink. We thought, ‘What if we take one of these devices (heat radiators), that we place it in a hot spot and that we direct it towards the sky? A normal solar cell generates energy by absorbing sunlight, causing the voltage to appear across the device and current to flow, (but) in these newer devices light is emitted instead and current and the tension goes in the opposite direction, but you still generate energy. You have to use different materials, but the physics are the same.
We don’t yet know how much power this new device can produce, the team estimates that it can produce up to 50W at night and are still working to improve its efficiency and find the most suitable material to use.