“The heat engines are made from a different kind of cell than a photovoltaic cell”
When we think of solar panels we think of the sunshine bearing down on photovoltaic cells used to produce clean electricity. The big drawback has been lack of sunshine, which diminishes their ability to produce electricity during the nighttime hours and on cloudy days. For households surrounded by trees, I often hear the excuse, “We can’t install solar because the sun doesn’t hit our roof, yard, ect.”
There is some recent exciting news! Scientists have discovered a new way that solar can generate electricity with lack of sun and during nighttime hours. Researchers have discovered that if you want to generate electricity at night you need a system that does the opposite of what solar panels do during the day. They are calling the new tehnology anti-solar or “heat engines.”
Photovoltaic vs Thermoradiative Cells
These “heat engines” are made from a different kind of cell than a typical solar photovoltaic cell normally thought of when producing clean energy. The new cell is called a thermoradiative cell and works the opposite of the photovoltaic cell.
Jeremy Munday, professor in the Department of Electrical and Computer Engineering at UC Davis is currently busy developing nighttime solar cells that can generate up to 50 watts of power per meter with hopes of improving the power output with further research. Munday states, “Our device couples the cold side of the thermoelectric module to a sky-facing surface that radiates heat to the cold space and has its warm side heated by the surrounding air, enabling electricity generation at night.”
In a recent paper published in the journal of ACS Photonics, Jeremy Munday explained, “A regular solar cell generates power by absorbing sunlight, which causes a voltage to appear across the device and for current to flow. In these new devices, light is instead emitted and the current and voltage go in the opposite direction, but you still generate power. You have to use different materials, but the physics is the same.”
With the ability to generate electricity around the clock, overcoming the lack of sunshine on cloudy days and long nights, we can move towards a sustainable planet, one more effort in combating our changing climate.