Alexander Dennis Enviro400EV

The Alexander Dennis Enviro400EV is a battery electric double-decker bus produced by the British bus manufacturer Alexander Dennis in partnership with Chinese electric vehicle manufacturer BYD Auto since 2018. Based on its Alexander Dennis Enviro400 City body, which was launched in 2015 to compete with the hybrid electric New Routemaster, the Enviro400EV is produced at Alexander Dennis' Falkirk and Scarborough factories in the United Kingdom, with production of the type at the company's Larbert headquarters set to also commence in mid-2023. The Enviro400EV is available both as a complete integral battery electric bus and as a battery electric bus body on a BYD K series chassis, as well the integral Enviro400FCEV fuel cell bus.

Description
In 2018, Alexander Dennis launched the Enviro400EV in partnership with BYD Auto, based on the Enviro400 City body and built on a BYD chassis. It is the second battery electric bus model from Alexander Dennis, following 2016's launch of the single deck Enviro200EV, also produced in partnership with BYD. Initially, the first 10.9 metre Enviro400EVs first entered service with Transport for London operator Metroline on route 43 in 2019, followed by a shorter 10.3 metre variant launched in 2021.

Alexander Dennis added to the EV range by introducing the Enviro400FCEV fuel cell bus in 2021, with the first completed example of the type being shown at the 2022 Euro Bus Expo. The Enviro400FCEV can be equipped with either a 45 kW or 60 kW Ballard FCmove-HD hydrogen cell as well as a 30 kWh electric reserve battery from Impact Clean Power Technologies, and the Enviro400FCEV has a maximum power output of 350 kWh provided by the Voith Electrical Drive System, offering a maximum range of 300 mi.

A second-generation Enviro400EV, featuring a newly restyled exterior and driver's cab, a new Voith driveline with a 410 kW peak power output, as well as options for either 472kWh or 354kWh NMC batteries repositioned further towards the front of the bus, was announced by Alexander Dennis in November 2022, with the first complete bus unveiled in November 2023. An open top variant was also announced upon the launch of the second-generation Enviro400EV.

BYD D8UR Enviro400EV City
Large numbers of first-generation Enviro400EVs on BYD chassis have entered service with London's bus operators for TfL bus services across the city. Customers include Go-Ahead London, who alone have ordered 169 of the type for delivery throughout 2023, Metroline, RATP Dev Transit London, Stagecoach London and Abellio London. Ten of Stagecoach London's Enviro400EVs were used to shuttle delegates and world leaders at the 2021 United Nations Climate Change Conference in Glasgow prior to entering London service,  while a batch of Abellio Enviro400EVs operating on route 63 were delivered with enhanced interiors specified under TfL's Future Bus project. Go-Ahead London also took delivery of eighteen Enviro400EVs fitted with pantograph chargers for service on route 132 in 2021.

National Express West Midlands and National Express Coventry are also major operators of first-generation Enviro400EVs, with its first 19 entering service in Birmingham in July 2020 and an additional 10 arriving at Coventry later in the year. National Express Coventry began taking delivery of an order of 130 Enviro400EVs in late 2022 as part of a plan for Coventry to have the first all-electric bus fleet in a UK city, with the completion of the order in September 2023 coverting the National Express Coventry fleet to 80% zero-emission vehicles. A further 170 Enviro400EVs were ordered by National Express West Midlands in April 2023, which upon their delivery in 2024, will take National Express' total fleet of Enviro400EVs in the West Midlands to 329. National Express Transport Solutions, the tour coaching arm of the National Express Group, also took delivery of four Enviro400EVs in May 2022 for tourist shuttle services to the Warner Bros. Studios, Leavesden.

Stagecoach Manchester took delivery of 32 Enviro400EVs in early 2020, which were allocated to the Sharston depot for service in South Manchester. In addition, Stagecoach in Cambridge received two in February 2020 on the Cambridge Citi 6 service. 22 Enviro400EVs were also delivered to Stagecoach Bluebird for service in Aberdeen in April 2022, which were joined by 13 more in 2023; Stagecoach West Scotland also received two Enviro400EVs for service in Ayrshire in this same order.

First Leeds ordered five Enviro400EVs for the Stourton Park & Ride, which entered service with the opening of the site in mid-2021, while First Glasgow also ordered 91 Enviro400EVs alongside 22 Enviro200EVs in 2021. Delivery of the first batches of these buses began following the COP26 conference. Four Enviro400EVs were delivered to Lothian Buses in March 2021 with branding advertising Scottish Power, who helped to fund Lothian's order for the buses, and 12 Enviro400EVs were delivered to Xplore Dundee, entering service in early 2022.

Transport for Greater Manchester ordered 100 Enviro400EVs in 2022 for use on its franchised 'Bee Network' bus services, which commenced operations in September 2023; the first 50 buses began to be delivered to Go North West for Bee Network services in Bolton in June 2023, and the remaining 50 entered service with Stagecoach Manchester in Oldham from March 2024.

Enviro400FCEV City
Twenty Enviro400FCEVs were ordered by the Liverpool City Region Combined Authority for use on contract to both Stagecoach Merseyside and South Lancashire and Arriva Merseyside. The "publicly-owned" hydrogen buses are branded for Liverpool's MetroBus network and operate on service 10A, Liverpool's busiest bus route which connects the city with St Helens via Knowsley. The first bus from this order was completed in November 2022, and the first buses started entering service in May 2023.

Second generation (2023-present)
The Stagecoach Group were the first operator to order and take delivery of the second-generation Enviro400EV, taking delivery of the first of 55 Enviro400EVs for Stagecoach West's Oxford depot in March 2024, branded as 'electro' buses for use in the Oxford SmartZone. A further 180 were ordered by the group for delivery between 2025 and 2026, intended for Stagecoach subsidiaries receiving central government funding from the Zero-Emission Regional Bus Areas (ZEBRA2) scheme, and 17 Enviro400EVs built to TfL specification were additionally ordered by Stagecoach London for delivery in early 2025.

Transdev Blazefield's Harrogate subsidiary is to take delivery of 19 Enviro400EVs equipped with pantograph chargers for use on the 36 service between Harrogate, Ripon and Leeds from September 2024, with the first bus from the order delivered to the company in June 2024.

Reading Buses is to take delivery of 24 Enviro400EVs to replace biogas double-deckers on its Purple 17 and Claret 21 services, the latter serving the University of Reading, in June 2025 as part of a 53-vehicle order for Alexander Dennis buses placed by the operator.