In the short term a gas tanker truck would be required to deliver the hydrogen to the bus garage but longer term the hydrogen could be delivered via the existing mains gas pipelines. This means that FCEV buses can be suitable for both inner city bus garages where there is insufficient electricity grid capacity and very rural bus garages where there is no suitable electricity grid. The only tailpipe emission from a FCEV bus is water vapour.
BEV’s are becoming very popular for passenger cars which typically drive for only a few hours a day and can be charged for 6 to 8 hours overnight. However, a BEV driveline is not optimum for all city bus applications because these can require up to 22 hours of driving per day and this leaves insufficient time for battery charging. Also, for longer and higher speed bus routes it isn’t always feasible to install enough battery capacity on the bus to meet the daily distance requirement. Due to these limitations, it is sometimes necessary to buy more than one BEV bus to replace one diesel bus.
Another challenge with BEV buses is the installation of sufficient electricity grid capacity to charge the buses. Typical UK bus garages can have around 100 buses. Charging this number of buses simultaneously requires at least a 33kV connection to the grid. It can cost around £1 million per km to bring such a high powered electrical supply to a bus garage and this assumes that the local electricity grid has enough spare capacity. To put this into perspective, a 33kV supply is normally enough to supply a town of 5000 houses.