Experimental investigation of photoelectrical performance and thermal characteristics of ventilated building-integrated photovoltaic system utilizing lightweight and flexible crystalline silicon module

Abstract

The existing large-scale of industrial buildings with lightweight insulated roofing structures presents a challenge for traditional glass crystalline silicon photovoltaic (PV) systems due to insufficient load-bearing capacity. Meanwhile, traditional PV rooftop applications also face challenges due to limited rooftop resources. To address these issues, this study proposes a ventilated building-integrated lightweight photovoltaic (VL-BIPV) system. The VL-BIPV system incorporates lightweight and flexible crystalline silicon modules, which increase rooftop load by about 6 kg/m2. Additionally, the system features a ventilation channel design to enhance thermal management performance. To evaluate the PV performance and thermal characteristics of the proposed system, an experimental setup was implemented to compare the performances of the VL-BIPV system with a building-attached lightweight photovoltaic (L-BAPV) system that utilizes color steel sheet base plates. The results demonstrate the exceptional performance of VL-BIPV system, with a 100.56% higher ratio of the product of short-circuit current and open-circuit voltage compared to L-BAPV. Moreover, the VL-BIPV system achieved a 1.77% increase in PV efficiency and a 2.35% enhancement in daily electricity generation. In hot weather, the adoption of VL-BIPV reduced the extreme temperature of PV cells by 9.23 °C below 85 °C, surpassing the 6.29 °C reduction achieved by L-BAPV system. Furthermore, the ventilation channel exhibited a gradual temperature increase with slower changes in the flow direction, while the base plate temperature decreased by 13.41 °C, which indicates that VL-BIPV can effectively reduce solar heat gain in the building envelope and improve the indoor thermal environment. The research findings provide important guidance for promoting and applying VL-BIPV technology in large-scale industrial buildings with low rooftop load-bearing capacity, thereby promoting the production and utilization of clean electricity in industrial parks.