Watertightness Design and Experimental Evaluation of a Solar Panel Structure for Building Integrated Photovoltaics (BIPV) Roofs

Building integrated photovoltaic (BIPV) roof technology is gaining popularity and its durability is of concern to different interest groups—watertightness is an important aspect. This study proposes an optimized solar panel structure for BIPV roofs, which aims to achieve watertightness performance; further, watertightness experiments with static and dynamic rainfall (the max wind speed level was 12) were conducted based on GB/T 15227–2019 standard through third-party testing. The results show that the BIPV roof system proposed has good watertightness performance; the water leakage grade is “not severe”. In addition, this study compares the technology application differences of three BIPV roof prototypes and discusses the effectiveness of red dyed test strips in characterizing water leakages. The proposed structure can be a reference for architects and engineers in the early design stage of BIPV roofs, which effectively enhances the durability and the cost investment of waterproofing materials.