Ventilation and heat dissipation analysis of photovoltaic roof

Abstract In recent years, the development and utilization of new energy have attracted more and more attention. As a green and clean energy, the utilization and development of solar energy have attracted much attention. Moreover, solar photovoltaic (PV) technology has been vigorously promoted, with building-integrated photovoltaic (BIPV) technology widely used in the building sector. However, in BIPV, although PV modules can be used as building envelope materials and provide electricity for buildings, due to various conditions during installation and design, PV modules are prone to overheating problems and affect photovoltaic performance. Hence, in the present study, a novel type of PV roof structure with lightweight crystalline silicon PV modules installed on the building surface is proposed, and an air space is provided between the novel lightweight crystalline silicon PV modules and the building surface, the novel lightweight crystalline silicon PV module has the characteristics of thinness and flexibility. After that, an experimental test platform with air space is established, and the data of typical meteorological days are selected to analyze the electrothermal performance of the novel lightweight PV roof, to obtain the optimal structure with the best PV performance. The results show that, under the same conditions, when the spacing is 0 mm and 80 mm, the temperature of the backplane and the substrate of the PV module gradually decreases with the increase of the air space. In contrast, the PV power and electricity generation gradually increase with the growth of the spacing. At the same time, when the distance exceeds 40 mm, the changing trend of the backplane of the PV module temperature, the temperature of the roof substrate, and the electricity generation is not apparent. In the present study, the optimal spacing of the novel lightweight PV roof is 40 mm.