Stanford engineers discover extra chill solar cells in US

Stanford based three engineers have discovered a technology that pushes away the heat generated by a solar cell under sunlight and cools it off converting more photons into electricity.

The work of Stanford’s electrical engineering professor Shanhui Fan, his research associates Aaswath P. Raman and doctoral candidate Linxiao Zhu has been described in the issue of Proceedings of the national Academy of Sciences.

The new discovery overpowers inefficiency of solar cells to produce electricity after being heated up as it cools off solar cells underneath. A typical solar cell with an efficiency of 20% will gain over 1% of energy production in 55F cooling.

The team tested their technology on a customized solar absorber covered with transparent silica photonic. The material powers solar cells from the sunlight but also emits thermal radiation through infra red rays. Hence it boosts up the performance of the cell underneath.

According to Fan in a Stanford report: "Solar arrays must face the sun to function, even though that heat is detrimental to efficiency. 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."

The discovery can be used for smaller applications like automotive air conditioning or at large scales where energy is just as important as coolness and could benefit from extra chill solar cells.

In 2014, the same trio developed a "radiative cooling" with an ultrathin material that radiated infrared heat back into space without warming the atmosphere.