Self-cooling solar cells are now possible with the help of tiny glass pyramids
When solar panels are used to give away power, are using small solar cells that need to have direct sunlight a long time. This is not a very difficult task, but can rise problems from time to time. As the solar cells heat up, their efficiency level is going down and the age quickly. Taking all this into account, the solar energy is not as cheap as we might think.
There are many ways the can get cooler in an active way, but this ways are generally not as cheap as we wish and they can also be problematic from the efficiency point of view. So, we might want to develop passive methods to cool the cells. In order to do this, a team of researchers from Stanford University developed a solution.
The highest level of efficiency reaches only conversion rates for the solar power they harvest, even if we are getting closer to a 50% rate. The remaining heat can be considered waste, as it brings the cells to 55 degrees Celsius. Every Celsius degree means a 0.5% cell efficiency decrease. This means that an efficiency levels at 30% is only bringing approximately 21% solar power.
The Stanford researchers brought a passive cooling solution by making use of the wavelengths of light. In order to do this, they use a thin sheet of silica glass among with the pyramids and shapes only a few microns thick. This means that visible light can enter through the glass unimpeded, but it also refracts away the infrared wavelengths that can be the cause of the extra heat.
In conclusion, with just a little extra cost, the additional glass layer can passively cools down the cells and the efficiency level can remain the same. Moreover, the live of the cells is longer, and an ideal efficiency level is to be reached. So far, this theory has been tested in a lab, but some outdoor test will be run in the near future. If these are successful, it might become a standard procedure for the next solar panel production, thanks to the big efficiency advantages.
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