Radiative sky cooling of silicon solar modules: Evaluating the broadband effectiveness of photonic structures

Photovoltaic solar cells are designed to efficiently absorb solar photons but convert only a limited proportion of them into electricity. Under real operating conditions, the remaining energy causes solar modules to heat up to 50–60 °C, which is detrimental to their power conversion efficiency and lifetime. In recent years, there has been a growing interest in the so-called radiative sky cooling strategy. 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 range. In this paper, we present an in-depth analysis of radiative sky cooling applied to silicon based photovoltaic modules. A simulation of a preliminary design of a photonic structure for possible radiative sky cooling of a module is also proposed.