Coating developed by Stanford University engineers could help solar cells be cooler
Sep 25 2015
The solution, proposed by Stanford electrical engineering Professor Shanhui Fan, research associate Aaswath P. Raman, and doctoral candidate Linxiao Zhu, uses a material that is able to capture and emit thermal radiation (heat) away from the solar call.
In 2014, the same trio developed an ultra-thin material that radiated infrared heat directly back toward space without warming the atmosphere.
Solar panel technology has improved by leaps and bounds, but the technology has a flaw that limits the efficiency of the system. A standard silicon cell, for example, will drop from 20 to 19 percent efficiency by heating up just 10° C (18° F) or so.
The tests were performed on a custom designed solar cell, which is similar to the commercially available solar cells, but it does not produce electricity. The coolness of space, approaching absolute zero, would negate the need for elaborate and expensive heat dissipation contraptions - if only we had a way to access it from the ground. Their experiments showed that the overlay allowed visible light to pass through to the solar cells, but that it also cooled the underlying absorber by as much as 23 degrees Fahrenheit.
The engineers tested the overlay using a custom-made solar absorber, which mimics the properties of a solar cell without actually producing electricity. "So you can radiate heat efficiently without affecting color".
They estimate the device could boost efficiency of the cell by more than one per cent, marking a significant improvement in energy production.
A team of scientists has developed a novel transparent coating that will help keep the solar cells cool and significantly increase their efficiency.
The Stanford researchers recommended that the transparent overlays would ideally be suited for clear and dry environments, which happen to be ideal for large solar panels.
Engineers stated that their invention would prove beneficial in nanoprint lithography technique used to develop nanometer-scale patterns. I'm optimistic. Thermal overlays can help with passive cooling, but it's a problem if they're not fully transparent. Therefore, any overlay would have to be transparent, or to be tuned to absorb only light beyond the visible spectrum.
"Our photonic crystal thermal overlay optimizes use of the thermal portions of the electromagnetic spectrum without affecting visible light", Zhu said.
Stanford University Develops A Wonder Material For Solar Panels
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