Photovoltaic louvers integrating radiative cooling and phase change materials: A comprehensive analysis of power generation and thermal management

Building-integrated photovoltaic (BIPV) systems face performance challenges due to temperature-induced power generation degradation. A photovoltaic (PV) louver incorporating phase change material (PCM) and radiative cooling (RC) technology has been proposed to suppress daytime temperature rise in PV modules and accelerate nighttime regeneration of the PCM. Experimental results indicate that PCM reduced the PV module temperature rise by 2.18–2.28 °C, reaching the maximum reduction of 2.28 °C at a louver tilt angle of 0°. With RC integrated, the louver cooling time was further shortened by 14.33–34.67% compared with natural cooling, and the greatest reduction (34.67%) was also obtained at a louver tilt angle of 0°. Multiple linear regression analysis indicates that the effects of louver tilt angle and PCM on power generation are comparable, contributing 54.77% and 45.23%, respectively. In contrast, for louver cooling, RC dominates the cooling performance, accounting for 76.54% of the cooling effect, substantially exceeding the influence of tilt angle adjustment. Overall, coupling daytime PCM thermal buffering with nighttime radiative cooling enables an effective day–night thermal management cycle for PV-PCM-RC louver system, reducing temperature rise and associated power degradation while accelerating PCM regeneration for BIPV applications.