Modelling and Assessment of System Costs and CO2-Emissions for Electrification of Bus Fleets

The transition of mobility from fossil-fuelled to emission-free drives is gaining speed in public transport. Transport companies have to face challenges in increased complexity when identifying an optimum system approach and choosing the most suitable technology. A modelling and evaluation approach is introduced to compare the diesel to several battery-electric bus systems and permits the assessment of the importance of each of the system components. Although the modelling is quite simple, the use of data derived from several years of bus operation provides reliable results that show annualized costs are about 30 percent higher and that the main cost drivers are the high investment costs for buses and batteries. CO2 emissions have been reduced by at least two-thirds whereas the remaining emissions mainly result from the manufacturing of the batteries. Sensitivity analyses show that a carefully thought out matching of bus and battery lifetime is crucial in order to optimize both annual costs and emission savings. Due to the simplicity of the model, it can easily be adopted by other transport companies and yet high quality of results can be ensured while still relying on data derived from bus operation.