Sustainable planning of electric bus systems: Degradation-aware and climate-specific techno-economic analysis

The transition to battery electric buses (BEBs) offers a promising pathway to decarbonize urban transport. However, planning their deployment requires careful evaluation of both economic and environmental trade-offs. This study presents a novel planning framework that jointly minimizes the total cost of ownership (TCO) and greenhouse gas (GHG) emissions by optimizing onboard battery size, charger power, and number of chargers, while incorporating a detailed battery aging model to capture real-world degradation under varying temperatures and charging conditions. A comparative analysis is conducted across four cities-Singapore, Adelaide, Munich, and Calgary-each representing distinct climate profiles, electricity prices, and grid emission intensities. The study also evaluates three widely used lithium-ion battery chemistries: LFP, NMC, and NCA. Results reveal substantial variation in optimal BEB configurations across regions. Colder cities require larger batteries and higher charging power to maintain reliability, resulting in increased costs and emissions, while milder climates with cleaner grids support more cost-effective and sustainable solutions. Critically, the analysis demonstrates that no single configuration performs best across all locations or chemistries-underscoring that one-size-fits-all approaches are unsuitable for BEB planning. These findings provide actionable insights for policymakers and transit agencies aiming to deploy BEBs effectively under diverse regional conditions.