Performance enhancement of building roofs integrated flexible photovoltaics in tropical weather via optimal PCM configuration

Integrating flexible photovoltaics with building roofs is a promising solution for sustainable urban development, yet temperature-induced efficiency degradation and structural loading considerations remain critical challenges, especially in tropical climates. To address these issues, this study proposes a novel Roof Integrated Flexible Photovoltaic-Phase Change Material (RIFPV-PCM) system to enhance thermal regulation and energy efficiency. A computationally efficient theoretical thermal model is developed based on energy balance approach to evaluate system performance. Based on this model, a computational program is implemented to conduct simulations, with specific analyses performed under tropical weather conditions in Sanya, China. Key parameters, including PCM thickness and phase change temperature (PCT), are optimized to maximize energy efficiency. Results demonstrate that for effective thermal management, 40 mm PCM layer with a PCT of 45°C prove to be efficient during summer months, enabling superior heat absorption and nighttime recovery. Furthermore, a thickness of 60 mm and a PCT of 35°C achieve optimal performance, yielding a 5.10% increase in annual energy generation. From the material optimization perspective, the ideal PCT varies depending on PCM thickness, with higher PCTs being advantageous when balancing material usage and structural load constraints. These findings not only validate the model’s practicality but also highlight its dual role in advancing carbon-neutral building design and PV durability.