Al₂O₃/graphene/PVDF-HFP radiative cooling coating reinforced heat dissipation of BIPV modules

Building integrated photovoltaic modules, applied to industrial and commercial buildings, generally used metal as the backsheet. In summer, the operating temperature of modules is as high as 70 degrees C, resulting in instability of output power and service life. Therefore, it is very important to reduce the operating temperature of photovoltaic modules. In this work, Al2O3/graphene/poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) composite radiative cooling coatings were prepared and utilized for reinforcing heat dissipation of photovoltaic modules. The results indicate that 0.75 wt%Al2O3/1wt%graphene/PVDF-HFP composite coating exhibited a thermal diffusivity of 3.24 mu m(2)/s and an average emissivity of 0.94. The maximum temperature drop of the coating in the outer door reached 5.8 degrees C. In addition, a mini photovoltaic module coated with the composite coating achieved the cooling effect of 2.4 degrees C, and the output power and conversion efficiency were increased by 5.8% and 7%, respectively. This demonstrates that the heat conduction radiative cooling coating possesses potential applications for improving the reliability of photovoltaic modules.