The future of zero-emission buses will include a mix of battery- and hydrogen fuel cell-electric – and possibly also hydrogen combustion, outgoing ComfortDelGro Group Engineering Director Ian Foster said in a panel session at the Association of Local Bus Managers (ALBUM) conference in Edinburgh on 26 April.
Mr Foster was joined by Warrington’s Own Buses Managing Director Ben Wakerley, Lothian Buses Engineering Director Colin Barnes and EO Charging CEO Charlie Jardine. Mr Wakerley opened the segment by revealing that the Volvo BZL, with charging infrastructure from EO, is expected to form the Cheshire operator’s fleet of 105 battery-electric buses.
Speaking about the choice between batteries and hydrogen, Mr Foster says that range is presently the defining factor. “Our experience is that battery technology is not advancing as quickly as we were told it would,” he notes.
Management of battery-electric vehicles is more challenging than for diesels, but experience of a batch of Wrightbus StreetDeck Hydroliners by ComfortDelGro subsidiary Metroline has demonstrated that those buses can be operated in much the same way as diesels.
To manage battery life, Metroline rotates its over 200 battery-electrics through each daily duty and charges them appropriately. As a result, they receive a full charge relatively infrequently. Mr Foster would like to see parts for battery-electric models drop in price. While he acknowledges that will come in time, a greater degree of commonality across manufacturers would also be beneficial.
But while vehicle choice remains a major consideration for decarbonisation, Mr Wakerley says that experience thus far in the transition of Warrington’s Own Buses’ fleet has demonstrated that they are no longer the factor upon which the zero-emission transition hinges. That is infrastructure, and in particular, ensuring that sufficient power is available in depots for battery-electric buses.
Lothian is at the start of its zero-emission journey, but Mr Barnes – who joined from Go North East recently – has previous experience of battery-electric. The Edinburgh operator’s large fleet and the age of its depot estate will make the shift difficult. Mr Barnes says that he expects the approach “to be flexible” as technology advances.
Whether batteries or hydrogen are the route for Lothian remains to be seen. “We are totally open-minded,” Mr Barnes continues. “Initially our interest will be in battery-electric, but we are watching hydrogen.” While batteries will suit some Lothian applications, others will be more challenging. That could be where hydrogen enters, although opportunity charging is a further possibility.
However, Mr Barnes underlines Mr Wakerley’s point about power supply for battery-electrics. “Never rely on the timescale given and always be flexible,” he says. “If you are told six months, allow 12.”
