Solar Cells That Could Generate Electricity At Night

One of the major drawbacks of solar panels is that they do not work at night. And for obvious reasons too: they depend on sunlight and, as an astronomical rule, the sun does not shine at night.

The Anti-Solar Panel

In early 2020, the solar community buzzed with the news that this paradigm had been challenged when Jeremy Munday, a professor of electrical and computer engineering at the University of California - Davis and a colleague, published a research paper in which they claimed to have developed a technology that could make solar panels work at night. CNN's coverage of the news included interviews with Mr. Munday. According to the two researchers, already existing prototypes of their new solar cell could generate up to 25% of a daytime solar panel, that is 50W per square metre.

Their 'anti-solar cell' works, not as a photovoltaic cell that generates electricity directly, but as a 'thermoradiative' one that generates electricity by a temperature difference that is created by the earth radiating away infrared ray at night. Generally, non-black bodies will radiate heat energy in the form of infrared waves to its surroundings when there is a temperature difference. In the conventional scenario, during the day when the sun's temperature is higher than that of the solar cell, it radiates energy that is received by the solar panel. At night, the earth is faced away from the sun and thus, the part of space around it is rather extremely cold because the earth blocks away the rays of the sun from reaching it. Under this temperature difference, any warm object pointed at the sky will radiate heat towards space in the form of infrared rays. With the temperature difference in the radiating material, a voltage and current is generated.

This technology is a rather simple and primitive one. Traditionally, food was cooled by placing them outside and facing them towards the sky at night so they can radiate away heat and become cooler. Theoretically, the anti-solar cell can generate light during the day as well. By being blocked from the sunlight and thus maintaining the temperature difference.

The researchers conceded in great modesty that there are many limitations to their technology. But they remain committed to further developing new and more sophisticated prototypes of their solar cell. It needs not be said the impact this innovation would have on the solar industry--when and if, it can fairly compete with existing night-time power storage technologies. We are still very far away from it but evidently, time is the only odd. Solarkobo helps homeowners and business in Lagos and throughout Nigeria design and install solar and inverter systems that help them meet their power needs and that fits their budget.