Fuel trends in route buses; the impact on vehicle package design

This research reviews fuel trends in current route buses by examining the state-ofthe-art development for five alternatives to diesel fuel and subsequent impact on vehicle package design. Natural gas (NG), fuel ethanol (FE), hydrogen fuel cell (FC), hybrid electric vehicle (HEV), and electric vehicle (EV) systems are considered. The review covers availability, sustainability, system complexity, and local emissions produced during operation. Each fuel system is evaluated with a focus on design opportunities offered to route buses operating on Australian roads. Hydrogen fuel cell and electric vehicle systems display suitable characteristics for route bus operation; zero local emissions produced during operation and capability for energy capture through regenerative braking. However FC systems are a difficult investment for Australian operators due to their associated cost and complexity. Thus, EV systems display the greatest potential benefit to route buses operating in Australia and encourage further exploration through vehicle package design. Discussion is formed around a knowledge gap identified within current fuel trials, which are applied by way of a retrofit approach over existing diesel vehicle package. Further exploration into potentials of an EV system requires the application of a ground-up approach for designing, testing and refining an EV-centred route bus vehicle package. The research concludes by proposing potential areas of exploration when applying a ground-up approach to an EV vehicle package including saloon floor height, saloon ceiling height, vehicle roof height, arrangement of doors and modularity throughout the vehicle.