Annual energy analysis of a trigeneration solar system using radiative cooling in Mediterranean climate

Radiative cooling with the outer space as a natural heat sink can be very useful in order to widely diffuse the standard of Nearly Zero Energy Building in Mediterranean climate. Despite it is a well-known passive technique, it is not so commonly used due to low power density and long payback periods. Recently, the integration of a radiative cooler into a solar photovoltaic/thermal collector is gaining increasing interest in research as a solution to overcome these drawbacks. In this study, the energy performance of a system converting solar energy into electricity and heat during daytime and offering cooling energy at night is assessed on the basis of a validated model of a trifunctional photovoltaic–thermal–radiative cooling module. The key energy performance indicators are analysed by varying the main parameters of the system such as spectral emissivity of the selective absorber plate and cover, and thermal insulation thickness. The annual performance analysis is performed for a typical residential building and climate of the Mediterranean area.