Life cycle externalities and abatement costs of public transport electrification using fuel cell and battery electric buses in Putrajaya city

City-level bus electrification is needed for urban decarbonization. Previous research shows varied preference between battery electric buses (BEBs) and fuel cell electric buses (FCEBs), due to region-specific factors. Hence, to determine the more practical option for deployment in a Malaysian city, this case study evaluates environmental and economic performance through life cycle assessment (LCA) and total cost of ownership (TCO) analysis, based on simulated energy consumption. The system boundary covers both vehicle and fuel cycles, assessing fossil-, solar-, and biomass-based hydrogen pathways. Results show that BEBs exhibit the lowest values across all three endpoint environmental impact categories, compared to all other FCEBs scenarios, with its environmental externalities priced at USD 831,587. They also achieve the lowest life-cycle GHG emissions at 58.1 kgCO2/100 km under Malaysia’s fossil-heavy grid, compared with the best FCEB scenario of 121.2 kgCO2/100 km. BEBs also yield the lowest TCO at 8.9 million USD and the lowest GHG abatement cost of 0.39 USD per kgCO2. The findings show BEBs deliver greater environmental-cost benefits than FCEBs, but future improvements in hydrogen supply chain might narrow this gap. Future work should assess whether FCEB deployment could be justified as a strategic option in helping a national hydrogen ecosystem development.