Optimal design of pure battery electric bus system on the grid network

Electrifying bus fleets is a practical way to develop sustainable transit systems. This study develops a continuous approximation model to provide strategic-level insights. Considering conventional depot charging mode, the proposed model optimises the design parameters of a pure electric bus network such as stop spacing, headway, and batteries' expected charging range. Numerical cases are presented over a wider range of key design parameters. Both analytical and numerical simulations are conducted to compare the results between the proposed system and the diesel bus system. Substituting electric buses for traditional diesel could save CO2 emissions from 47% to 52% and up to 8% of the total cost can be saved with electric buses, and deploying electric bus systems would bring an around 7% increase in capital cost but save 23% operation cost. On a real-world grid network in Xi'an, China, deploying electric buses can save the system cost by 7.7%.