Alexander Dennis unveils next-generation electric buses

02 November 2023

Alexander Dennis (ADL) launched its next generation of battery-electric buses for the UK and Ireland with the unveiling of the new Enviro100EV small bus and Enviro400EV double decker. The new buses have been engineered fully in house as zero-emission vehicles from the ground up.


The 11.1m-length Enviro400EV double decker is designed to shift the crowds on busy urban and interurban routes, and offers according to ADL a range of up to 260 miles. The Enviro100EV is a highly manoeuvrable small bus just 8.5m long and 2.35m wide, covering up to 285 miles on a single charge. Until now ADL developed electric buses using chassis from Chinese manufacturer BYD and says that in addition to its next-generation buses, it will continue to sell and support electric buses built in partnership with BYD. The new generation ADL buses are equipped with a zero-emission driveline developed in house. Voith Turbo supplies the Voith Electrical Drive System (VEDS), which has been specifically developed for the requirements of urban and interurban buses. While the Enviro100EV uses the medium-duty variant of VEDS, the heavy-duty version is employed in the Enviro400EV for gradeability and maximum reliability even at higher operating speeds.

ADL chassis

A future-proof battery system has been developed in partnership with Impact Clean Power Technology. Using NMC lithium-ion cells, it delivers a higher total energy throughput – up to 1.4GWh in the Enviro400EV. The battery packs are mounted within the chassis and rear of the vehicle as well as under the staircase of the Enviro400EV. Underfloor packs are mechanically isolated rather than directly bolted to the chassis, protecting them against external loads from twists and impacts that could cause premature failure. Impact is already planning a future iteration of NMC batteries for Alexander Dennis that is expected to increase range even further. With battery locations optimised to balance weight distribution and avoid intrusion into passenger spaces, the Enviro400EV double decker has a conventional lower saloon layout with a flat floor, improving legroom for seated passengers and increasing overall passenger capacity by up to 19%.

adl dash

The working environment for bus drivers has also been improved with a new steering wheel, configurable dashboard display and improved heating, cooling and ventilation in the cab. A redesigned geometry of the vehicle front provides drivers with better direct vision and protects vulnerable road users. Combined with further measures around the vehicle including latest assistance technologies, Alexander Dennis’s next generation of battery-electric buses meets current and upcoming targets of Transport for London’s Bus Safety Standard.


ompleting the support suite is AD Connect, a new, bus-dedicated telematics solution for enhanced diagnostics, parts and repair information. AD Connect is accessed directly through the AD24 portal or via integration into customers’ existing fleet management systems. The Enviro400EV will be assembled in Larbert, where Alexander Dennis has transformed its facility and overhauled its build process by introducing digital support tools and reducing the number of build stages to improve material, process and quality control.

The Enviro400EV and Enviro100EV for the UK and Ireland are part of the wider family of Alexander Dennis next-generation zero-emission buses that also includes the three-axle Enviro500EV double decker for international markets. An international version of the Enviro100EV is under development, as is the autonomous Enviro100AEV and an open-top variant of the double deck Enviro400EV.