Reconfiguring solar and thermal radiation through spectral-constraining and optimization to enable integrated solar photovoltaic conversion and radiative sky cooling

To achieve high radiative cooling (RC) performance during the daytime, the RC emitter must reflect most of the solar irradiance in order to minimize parasitic solar absorption. However, this requirement also implies that a large portion of available solar energy, a clean and abundant renewable resource, cannot be effectively utilized and is therefore wasted. To enable efficient utilization of the incident solar radiation while maintaining high daytime RC performance, this study proposes an innovative integration module of photovoltaic (PV) and RC modules based on a transparent compound parabolic concentrator covered with a transparent infrared reflective film (SS-TCPC), referred to as the CLARITY. In this paper, a comprehensive numerical analysis of modules integrating different SS-TCPC structures and RC emitter configurations is presented. Numerical simulations reveal that the solid SS-TCPC structure shows great solar concentration capacity to the PV module, maintaining sunlight receiving ratio above 0.90 over a zenith angle range of 0°–45°. In addition, inverted V-shaped RC emitters outperform CPC-shaped RC configuration by suppressing lateral sunlight guiding and preserving a high sky view factor, thereby maintaining effective cooling performance. Under zenith conditions, the net cooling power density on the sunward side exceeds 94.29 W/m2. This study reveals a viable strategy to integrate daytime RC with solar photovoltaic conversion, providing a new pathway for integrated building multi-energy utilization.