National assessment of transit electrification in Canada: infrastructure costs, energy demand, and greenhouse gas reduction potential.

Battery electric buses (BEBs) offer a scalable solution for decarbonizing public transit; however, comprehensive national-level assessments remain limited. This study presents the first bottom-up evaluation of BEB adoption across Canada, using open-source data from 102 transit providers. We quantify fleet requirements, infrastructure needs, electricity demand, and the cost-effectiveness of greenhouse gas (GHG) reductions under a fully electrified bus transit system. Our analysis indicates a required 17% increase in fleet size and an additional 1.255 TWh of electricity annually, representing just 0.20% of Canada's total generation. GHG emissions would decline by over 92% to approximately 130,000 tonnes annually, with the social cost of carbon falling by a similar margin (92.68%). These findings demonstrate that nationwide BEB deployment is technically feasible, economically manageable, and environmentally impactful. This study offers reproducible, open-source-based, critical evidence to guide energy planning, policy decisions, and investments in a sustainable, zero-emission transit future.