Decoupling curvature-induced electrothermal hazards via topology optimization for reliable curved BIPV

The geometric characteristics of curved surfaces introduce complex optical-electrical-thermal (O-E-T) coupling challenges, severely limiting the reliability of flexible photovoltaics (PV). Existing studies often treat electrical mismatch and thermal distribution independently, overlooking the critical mechanism by which current mismatch exacerbates temperature fields through localized Joule heating feedback. This paper constructs a spatially resolved two-dimensional O-E-T dynamic coupling model, revealing the physical pathway through which curvature-induced irradiation gradients translate into electrothermal hazards. The study demonstrates that hotspot formation in curved PV is not solely driven by uneven irradiation. Its root cause lies in the “current bottleneck” effect within series-connected topologies, where unutilized electrical energy converts into localized Joule heating. This mechanism causes severe overheating unpredictable by optical analysis alone. An electrothermal decoupling optimization criterion is proposed. By reconstructing the interconnection network along equal-irradiance lines (Type 2), current bottlenecks are eliminated, annual power generation increases by 151.9%, and hotspot formation is suppressed at its source. Ventilation's role is also clarified: its contribution to annual power generation is minimal (<0.2%), yet it functions as a thermal safety valve by eliminating all extreme high-temperature outliers exceeding the IEC standard (75 °C). This study establishes a hierarchical design strategy: topology optimization drives power enhancement, while low-energy ventilation ensures thermal safety, providing a theoretical foundation for reliability design in curved BIPV systems.