Increasing the energy density of batteries is a “primary focus” of bus manufacturers in the battery-electric segment, Alexander Dennis Group Engineering Director Chris Gall (pictured) told the ALBUM conference on 28 April.
Mr Gall – who joined ADL in 2021 – also notes that in addition to energy density, predictability of battery performance is a further imperative for the electric bus sector, and that such a position will allow vehicle OEMs to provide operators with “the best solution.”
Such work is already underway, he continues. Alexander Dennis predicts that over the next five to 15 years, energy density will increase by 50% and that the battery cost per kW/h will drop by around one-third from their current positions. Over a 15–30-year horizon, energy density is anticipated to grow to double what it is now, while cost per kW/h should reduce to one-third of its current level.
Such advances will allow increases in either range or passenger capacity, Mr Gall continues. Further major change to the total cost of ownership of battery-electric buses will come through the transition to solid-state storage. That is likely over the longer term and ADL has set its partners a target of achieving a 15-year battery life within that horizon, he adds.
But while energy storage is at the centre of ADL’s work on battery-electric vehicles, Mr Gall observes that improved overall efficiency is a further consideration. Much energy is consumed by the driveline and reducing that will also translate to greater range or passenger capacity.
Autonomy is a lesser consideration, and Mr Gall believes that it will likely come first in confined depot environments. However, the use of software to modify a vehicle’s response to driver inputs is another consideration. That would not disturb the feeling that the bus is still under the driver’s control but could increase efficiency significantly.