A group of researchers at Stanford University have developed a new type of coating, which will allow solar cells to cool themselves. This breakthrough would eliminate the need for water and energy intensive coolants and ventilation, which is currently used to cool solar cells. It would also extend the life span of the solar cells considerably.
On sunny days solar panels can heat up to 130 degrees Fahrenheit and more, which causes loss of efficiency and the shortening of their lifespan. The group of Stanford researchers now developed a new type of passive cooling technology, which might help solve this problem. Their findings were published in The Optical Society’s journal Optica. The way the team solved the cooling problem is by proposing the addition of a specially patterned layer of silica glass to the surface of regular solar cells, which eliminates unnecessary thermal radiation, and allows the cells to cool themselves.
The coating they developed is comprised of tiny pyramid and cone-shaped structures applied to a thin layer of the silica glass. This is then able to redirect the extra heat from the cells in the form of infrared radiation. This is possible because silica is transparent to visible light, and because it can be fine-tuned in terms of how it bends and refracts light of very specific wavelengths. By designing the silica layer in a controlled way, there is no performance loss to the solar cell, while it does enhance the radiation at the predetermined thermal wavelength to send the solar cell’s heat away more effectively.
In the course of researching this new technology, the scientists tested different shapes and sizes of cones and pyramids on the silica layer and also compared it to a flat layer of silica. During this process, they managed to fine tune the shapes and found a pattern that performed best. They also found that the patterned silica layer performed much better than the flat layer. The next step in the research process is to test the new technology in a real-world scenario.