Alexander Dennis has achieved a class-leading energy efficiency average of 0.67kW/h per km for its latest-generation Enviro400EV battery-electric double-decker during testing for zero-emission bus certificate accreditation.
The process was handled by Zemo Partnership at UTAC Millbrook. It puts the Enviro400EV as the most efficient battery-electric double-decker yet tested by Zemo. The figure quoted is an average across the UK Bus Cycle generated by a bus with 472kW/h of battery capacity. It comes as the first customer deliveries of the model are “imminent.”
A certificate posted on the Zemo website shows that such a return gives the bus a theoretical range of 620km. The UK Bus Cycle involves various driving simulations, with the Enviro400EV having turned in 0.71kW/h per km on the inner urban phase and 0.61kW/h on the rural part.
Alexander Dennis has credited use of the heavy-duty variant of the Voith Electrical Drive System for the return. The average of 0.67kW/h per km is significantly lower than an earlier simulated figure of 0.91kW/h for the same vehicle, which was calculated by Zemo prior to completion of the first ‘in house’ Enviro400EV.
Variation between the simulated and actual figures has been explained by the manufacturer as being the result of it “preferring to remain conservative in our calculations for simulated certificates,” a spokesperson says.
They note that the simulation “only takes a theoretical view of component performance without the fine-tuning that our engineers do on the prototype vehicles.” The same exercise has been undertaken on the Enviro100EV small single-decker.
Alexander Dennis does not expect to carry out actual Zemo testing on the 354kW/h version of its Enviro400EV. It is expected that the 472kW/h model will account for most orders and accepted that the 354kW/h option will by definition be more energy efficient. “This is sufficient to prove zero-emission bus status,” the spokesperson adds.
Speaking about the completion of testing at UTAC Millbrook, Alexander Dennis Group Engineering Director Chris Gall says that the 0.67kW/h per km return “sets a new benchmark and is testament to Alexander Dennis’s lineage and strength in designing innovative products meeting the needs of the UK bus industry.”
Adds Mr Gall: “The result demonstrates not just the expertise of our fantastic engineering team who designed the bus, but it also confirms the efficacy of the system of zero-emission bus testing overseen by Zemo Partnership.
“The process encourages us and our fellow UK manufacturers to continually raise the bar, bringing down customers’ operating costs through reduced energy consumption and ensuring the transition to zero-emission technology is both sustainable and profitable.”
