Contrary to popular thought, heat reduces solar cell efficiency. As the cells heat up from the direct glare of the sun, their efficiency in converting light into electricity drops markedly. Depending on the system used and the location, losses can reduce output up to 10 to 25 percent.
This conundrum has vexed the industry for many years. After all, solar cells need the sun to work and this generates heat. So how to solve this problem and increase the light-to-electricity efficiency of solar cells?
Enter a team of researchers from Stanford University who have developed a transparent coating for the cells. The film keeps the cells cool as they heat up under the sun. Made of patterned silicon, the secret to this remarkable film is that, while it allows visible light to pass, it also absorbs and even emits the infrared rays, the source of thermal radiation. [Continue reading…]