Lifecycle carbon dioxide emissions and cost assessment for battery electric bus systems

Battery electric buses (BEBs) have emerged as a promising solution for reducing transportation emissions; however, prior research has rarely addressed the combined environmental and economic impacts of BEB fleets and their charging facility. This study presents a comprehensive lifecycle assessment (LCA) framework that quantifies carbon emissions and total costs across the production, operation, and recycling phases of BEB systems, integrating heterogeneous bus fleets with diverse charger types and route-specific constraints. In a case study of a public transit network in Nanjing, China, seven scenarios with different BEB system configurations were evaluated. Results show that the capital cost of BEBs accounts for approximately 66% of the total lifecycle cost, with Scenario #1 costing $232.51 million and Scenario #3 reaching $377.07 million-a 62% increase. Sensitivity analyses further indicate that reducing the power grid carbon emission factor from 0.910 to 0.095 kgCO2e/kWh can lower lifecycle emissions by 81.3%, while a 5% increase in BEB energy consumption leads to a 4% rise in emissions, with only a 0.2% impact on overall costs. These numerical results substantiate the effectiveness of our coupled LCA framework by demonstrating that strategic interventions - such as grid decarbonization and improvements in BEB energy efficiency - can significantly mitigate both environmental impacts and lifecycle expenditures. Our findings provide critical quantitative insights for decision-makers, highlighting the potential for substantial reductions in lifecycle impacts as cleaner energy sources and advanced vehicle technologies become increasingly prevalent.