Global estimation of building-integrated facade and rooftop photovoltaic potential by integrating 3D building footprint and spatio-temporal datasets

<h2>Abstract</h2> This research tackles the challenges of estimating building-integrated photovoltaics (BIPV) potential across various temporal and spatial scales, accounting for different geographical climates and urban morphology. We introduce a holistic methodology for evaluating BIPV potential, integrating 3D building footprint models with diverse meteorological data sources to account for dynamic shadow effects. The approach enables the assessment of PV potential on facades and rooftops at different levels—individual buildings, urban blocks, and cities globally. Through an analysis of 120 typical cities around the globe, we highlight the importance of 3D building forms, cityscape morphology, and geographic positioning in measuring BIPV potential at various levels. In particular, within the analyzed areas, our study reveals that the total solar radiation received by facades is highly competitive with that received by rooftops, showcasing an average facade-to-rooftop ratio of 100.7%. Moreover, 35.9% of the facades receive even more total radiation than rooftops, further emphasizing their potential as viable solar energy surfaces. Despite the generally lower conversion efficiency of facade PV systems compared with rooftop installations, our simulation results indicate that the average ratio of facade PV potential to rooftop PV potential remains approximately 68.2%. Additionally, approximately 17.5% of the analyzed samples demonstrate even higher facade PV potentials compared with rooftop installations. This finding underscores the strategic importance of integrating facade PV applications to enhance the overall urban sustainable energy systems strategy.