Even when the sun goes down!The new photovoltaic cells can provide power 24 hours without interruption

2022-07-03 0 By

Financial Union (Shanghai, editor Huang Junzhi) news, according to statistics, there are about 750 million people in the world at night without electricity to use.Solar cells provide electricity during the day, but to be able to use it at night requires a lot of battery storage.In applied Physics Letters, published by the American Physical Union (AIP), researchers from Stanford University have built a photovoltaic cell that can capture energy from the environment during the day and at night, completely avoiding the need for large numbers of batteries.The device uses heat that leaks back into space from Earth – the same amount of energy as solar radiation entering the planet.The team demonstrated their device’s power generation process during the day and at night.During the day, the device works in reverse and provides extra power to conventional solar cells.At night, the solar cells radiate and emit heat into the sky to reach temperatures several degrees cooler than the surrounding air.The device under development uses a thermoelectric module to generate voltage and current from the temperature gradient between the battery and the air.This process depends on the thermal design of the system, including the hot and cold sides.The researchers say the device is cheap and could, in principle, be integrated into existing solar cells.It is also simple in structure, making it feasible to carry out construction in remote areas with limited resources.Lighting at night using electricity requires only a few watts of power, and the current installation can produce 50 milliwatts per square meter, meaning that lighting will require about 20 square meters of photovoltaic area.”What we’ve managed to do here is build the whole device out of off-the-shelf components, with very good thermal contact, and the most expensive thing in the whole device is the thermoelectricity itself,” says Zunaid Omair, author of the paper.”None of these components were specifically designed for that purpose,” he said. “So I think there’s room for improvement, in the sense that if we really designed these components for our purpose, I think the performance could be better.”Next, the team aims to optimize the device’s insulation and thermoelectric components.They are exploring engineering improvements to the solar cells themselves to improve their radiant cooling performance without compromising their solar energy collection capabilities.