Enhancing the performance of solar cells through radiative sky cooling
Photovoltaic (PV) cells heat up substantially in real operating conditions, which is detrimental to their energy conversion efficiency as well as their lifetime. The so-called radiative sky cooling (RSC) technique is a very promising concept to lower their temperature. This approach consists in optimizing the thermal radiation of cells or modules – with the help of photonic structures – by taking advantage of the atmospheric transparency in the 8-13 μm range.
Using a coupled thermal and electrical model developed at INL, the potential benefit of enhanced RSC was quantified for a wide range of PV devices. For crystalline silicon based devices, which represent 95% of the PV marketshares, the study shows that a cooling of 10 °C is achievable. This would increase the electrical power output by almost 5 W/m².
This impressive performance boost requires the modification of optical properties over a wide spectral range (between 1.1 μm and 40 μm) in order to improve thermal emission but also to reduce so-called “parasitic” solar absorptions. The team is now exploring different technological pathways to achieve the desired photonic properties.
This work has been published in the journal Sustainable Energy & Fuels and in PV Magazine (https://www.pv-magazine.com/2021/04/06/cooling-pv-modules-with-radiative-sky-cooling/).
J. Dumoulin, E. Drouard, and M. Amara : Radiative sky cooling of solar cells: fundamental modelling and cooling potential of single-junction devices. Sustainable Energy & Fuels, 2021. doi: https://doi.org/10.1039/D0SE01536A
Computing and data-processing resources needed for this work were provided by the CNRS/IN2P3 Computing Center (Lyon – France).