Urban-scale modeling of building energy self-sufficiency using rooftop photovoltaics

Buildings are major contributors to global energy-related CO₂ emissions, accounting for a significant share of global climate impacts. This has highlighted the critical need to transition toward a carbon-neutral building stock by 2050. Rooftop photovoltaics (PVs) offer substantial potential to reduce energy demand and enhance urban energy self-sufficiency. This work focuses on developing an improved CityBEM framework, an in-house urban building energy model (UBEM), to evaluate the role of rooftop PV systems in decarbonizing urban energy systems. The enhanced methodology enables city-scale, high spatiotemporal resolution simulations of both building energy use and rooftop PV retrofitting while addressing key computational and data limitations commonly faced in UBEM applications.

CityBEM’s robust and scalable approach allows for transient simulations of individual buildings with diverse usage types, making it applicable to large urban areas. The rooftop PV module incorporates physics-based modeling, validation, and optimized designs to account for self-shading effects and maximize energy generation potential.

Currently, the tool is being applied to model the entire city of Montreal. The goal is to generate high spatiotemporal resolution simulations of energy demand and on-site electricity generation from rooftop PVs. This framework aims to provide actionable insights into the role of rooftop photovoltaics in achieving cleaner, energy self-sufficient cities and informing strategies for large-scale urban retrofitting and decarbonization.