Estimating life-cycle carbon mitigation potential of building integrated photovoltaics (BIPV) facade at the city scale

Buildings contribute to 40% of global energy consumption and one-third of greenhouse gas emissions. To advance sustainable city goals, the adoption of renewable energy technologies across urban landscapes is essential. Building-integrated photovoltaic (BIPV) systems offer significant potential for reducing building energy consumption, serving as a critical component in climate change mitigation. Although previous research has highlighted the prospects of rooftop photovoltaics in urban areas, the limited space on urban roofs and the presence of rooftop equipment significantly constrain the installation of rooftop PV systems. In contrast, building facades present a promising perspective for the application of photovoltaic systems, especially in cities with a large number of high-rise buildings.

This research investigates the life-cycle carbon mitigation potential of Building-Integrated Photovoltaics (BIPV) façade at the city scale, with a focus on their deployment in densely populated urban areas. Initially, the study uses GIS spatial analysis to identify building geometry adjacencies and distinguish the areas suitable for the installation of facade photovoltaic systems. Then, we estimate the PV power generation potential of urban building facades, considering the shading impact from surrounding buildings. Finally, we quantify the carbon mitigation potential of urban facade photovoltaics from the manufacturing stage to the end of life, by calculating Cumulative Energy Demand (CED), Carbon Emission Rate (CER), Life-cycle Carbon Reduction Benefit, Carbon Payback Time (CPBT), and Energy Payback Time (EPBT).

This study aims to inform urban planners, policymakers, and stakeholders about the viability of BIPV as a solution for reducing urban energy consumption and advancing toward a low-carbon future. By analyzing life cycle phases, the results can also provide policy guidance to maximize the carbon mitigation benefits of BIPV.