Performance analysis of a hybrid system combining photovoltaic and nighttime radiative cooling

Abstract The concept of hybrid utilization of daytime photovoltaic (PV) conversion and nighttime radiative cooling (RC), namely, PV–RC, was proposed and experimentally demonstrated. A PV–RC hybrid module with a size of 1380 mm × 720 mm was manufactured and characterized, and a corresponding PV–RC hybrid system was established. The PV–RC hybrid system can generate electricity at daytime by PV conversion and simultaneously obtain cooling energy by nighttime RC. PV performance of the hybrid system was tested on a mostly sunny day, and measured results showed that the daily average electricity output and electrical efficiency were 94.0 W·m −2 and 14.9%, respectively. Besides, nighttime RC performance of the hybrid system was measured on a mostly clear night sky and net cooling power of the PV–RC system was evaluated as 72.94 W·m −2 when temperature of the PV-RC panel was equal to ambient air temperature. Furthermore, a validated thermal analysis model was used for parametric study and results show that nighttime RC performance will be enhanced by dry atmosphere and low parasitic cooling loss. In summary, this work presented an experimental and simulation study for PV–RC hybrid system, which acts as a demonstration project of a real system. This study is a new attempt towards a real-world application of comprehensive utilization of solar energy and RC, which provides a good choice for cooling demand dominated buildings.