Researchers from Stanford University have successfully improved the efficiency of solar cells and solar panels. They have developed a transparent overlay material, a patterned silica material on top of a normal solar cell, which increases solar cell efficiency by cooling cells in full sunlight. The material works by radiating heat away from the solar cells, according to Electronics Weekly.
“Our thermal overlay allows sunlight to pass through, preserving or even enhancing sunlight absorption, but it also cools the cell by radiating the heat out and improving the cell efficiency,” Shanhui Fan, professor of electrical engineering at Stanford, said.
When the material was tested, it cooled the solar absorber by 23 degrees Fahrenheit.
“For a typical crystalline silicon solar cell with an efficiency of 20%, 23 degrees Fahrenheit of cooling would improve absolute cell efficiency by over 1%, a figure that represents a significant gain in energy production,” researchers added.
The team also noted that this technology could be applied to other systems that need to be cooled but are exposed to sunlight.
“Say you have a car that is bright red. You really like that color, but you’d also like to take advantage of anything that could aid in cooling your vehicle during hot days. Thermal overlays can help with passive cooling, but it’s a problem if they’re not fully transparent,” Linxiao Zhu, co-first-author of the paper, said.
“That’s because the perception of color requires objects to reflect visible light, so any overlay would need to be transparent, or else tuned such that it would absorb only light outside the visible spectrum,” according to Electronics Weekly.
“Our photonic crystal thermal overlay optimizes use of the thermal portions of the electromagnetic spectrum without affecting visible light,” Zhu said, “so you can radiate heat efficiently without affecting color,” Zhu concluded.
