Zero emission buses: local authority toolkit

Buses are one of the least carbon intensive forms of road vehicle transport per passenger, per mile in the UK. Combined with coaches, they represented only 3% of UK transport emissions and 1% of total mileage in 2019.

They remain the most popular form of public transport, accounting for around 50% of all journeys on public transport.

Between 1990 and 2019, emissions have decreased by 42% as fuel efficiency has improved and zero emission buses have started to enter service.

Local transport authorities in England outside London are local authority bodies with responsibility for transport planning and public transport issues, typically county, unitary authorities and combined authorities.

They should work with bus operators, including through Bus Service Improvement Plans (BSIPs), to develop plans to decarbonise their bus fleet.

Local transport authorities also have an important role in accessing UK government funding for zero emission buses and accompanying supporting infrastructure.

Lower tier local authorities, such as district and borough councils, do not have a formal role in transport planning, but can work with local transport authorities to decarbonise the bus fleet in their areas.

What are zero emission buses?

Zero emission buses (ZEBs) are the latest development in bus technology and follow the introduction of low emission buses and ultra-low emission buses.

The UK government’s Zero Emission Bus Regional Areas (ZEBRA) scheme defines a zero emission bus as a bus:

The Ultra Low Emission Bus Certificate has been developed by Zemo Partnership (formerly Low Carbon Vehicle Partnership), an independent partnership funded by government and industry.

Earning the Ultra Low Emission Bus Certificate requires a bus to achieve a 30% well-to-wheel greenhouse gas saving compared to a conventional Euro VI diesel. Zemo Partnership are currently developing a Zero Emission Bus certificate.

The definition used for theZEBRAscheme includes battery electric and hydrogen fuel cell powered buses.

Battery electric buses operate using an electric motor powered by electricity from a battery charged using mains electricity.

In a hydrogen fuel cell bus, the fuel cell converts hydrogen (typically stored on the roof of the bus) into electricity to power the vehicle.

This definition ofZEBsexcludes:

An overview of various zero emission bus technologies can be found at the Zemo Partnership website.

In 2020,ZEBsaccounted for just 2% of England’s bus fleet, (4% of the London fleet and 1% of the fleet outside of London), while 84% of buses were diesel-powered.

Information about the area of operation of zero emission buses, and low emission buses across the UK can also be found on the Zemo Partnership website.

The benefits of zero emission buses

Zero emission buses will help local authorities achieve net zero targets, cleaner air, green growth and improved health and wellbeing outcomes.

As set out in Bus Back Better: national bus strategy for England, each zero emission bus reduces carbon emissions by about 70% (46 tonnes) annually compared to a diesel bus and also avoids the 23kg of nitrogen oxides (NOx) emitted by a diesel bus each year.ZEBsare also exempt from clean air zone (CAZ) charges.

For operators, zero emission buses have lower operating costs compared to diesel buses (though capital costs are higher). These savings can potentially be invested in service improvements.ZEBsalso provide an opportunity for operators to upskill their workforce.

For passengers,ZEBscan offer an improved passenger experience through reduced noise and vibration.

WhenZEBsare introduced under the right operating conditions, appropriately supported through promotional activity and combined with wider changes to the road network, they offer an enhanced passenger service.

This can encourage bus usage by offering a faster, cleaner and more attractive travel option than private vehicles.

Investment inZEBsalso has the potential to secure thousands of green manufacturing jobs and apprenticeship opportunities across the country, including in Scotland, Northern Ireland and the north of England. It can also support the decarbonisation of other transport modes. For example, investment in the electricity network for electric buses can be an opportunity to support other electric vehicles.

National policy direction

National Bus Strategy for England and Decarbonising Transport: A Better, Greener Britain set out the government’s most important commitments to decarbonising the bus fleet.

Five principles underpin government’s zero emission bus policies. They are that:

The government is committed to supporting the introduction of 4,000 zero emission buses (ZEBs).

Over this Parliament, the government has provided over £525 million to support the introduction of zero emission buses and supporting infrastructure. This includes:

The government has also committed to reforming the rate at which Bus Service Operators Grant (BSOG) can be claimed by zero emission buses to 22 pence per kilometre, to accelerate the take up of zero emission buses. This uplift will take place ahead of a wider reform of BSOG.

We are committed to setting an end date for the sale of new non-zero emission buses. An initial consultation was carried out in spring 2021 and a further full public consultation was launched in March 2022.

Zero emission bus technology

The 2 main zero emission bus technologies in the UK are battery electric buses and hydrogen fuel cell buses.

A battery electric bus operates using an electric motor powered by a battery charged using mains electricity.

In a hydrogen fuel cell bus, the fuel cell converts hydrogen (typically stored on the roof of the bus) into electricity to power the vehicle. Hydrogen can be produced from a variety of methods, including from fossil fuel based industrial processes to electrolysis of water using renewable electricity.

To deliver decarbonisation, local authorities need to ensure that low carbon hydrogen is being used to fuel buses wherever possible.

An emerging zero emission bus technology is to convert diesel buses to battery electric or hydrogen fuel cell buses.

Local transport authorities should work with bus operators in their area to determine which technology is most suitable in their local area, considering the nature of bus services and bus routes.

More information on various ZEB technologies can be found on Zemo Partnership’s website.

In 2020, the city of York council, working with First Bus, launched the largest ZEB park and ride fleet in the UK.

The 21 double deck electric buses were introduced with funding from the UK government’s Ultra Low Emission Bus Scheme. They have a 160-mile range and do not need to be charged during the working day.

The council worked in partnership with First Bus and Optare to develop the buses. The council’s iTravel site allows users to view details of the park and ride services.

Zero emission bus infrastructure

Zero emission buses will also require supporting infrastructure to operate.

Electric buses will require charging infrastructure and connections to the electricity network.

There are a number of different methods of charging electric buses:

Usually the least expensive option, buses plug in overnight. Rapid and ultra-rapid charging options are available which require less time to charge but are more expensive.

Buses are charged at various locations throughout the day. This can be at the bus depot, at a bus station or at set points along the bus route. The most common form of opportunity charging is pantograph charging using overhead cabling and roof-mounted equipment to recharge buses.

Other types of pantograph charging are available and ultra rapid plug in charging points can also be used for opportunity charging.

Opportunity charging is usually more expensive than overnight charging at depots using plug in charge points. Rather than relying only on opportunity charging, it is more typical for electric buses to use a combination of overnight charging and opportunity charging.

This emerging technology uses coils under the road surface to transfer energy to a bus stopped above. Dynamic wireless charging (of vehicles in motion) is still in pilot and development stages.

The decision on which charging method should be used will depend on:

The costs of connecting to the grid will vary depending on location but can be substantial. The Zemo Partnership estimates the cost of depot charging upgrades to be around 10% of the total project cost of overall fleet upgrade project costs.

The Confederation of Passenger Transport estimates the cost of upgrading a single bus depot at £1.5 million to £2 million, not including the cost of connecting to the electricity network.

Energy UK, the trade association for the energy industry, has produced guidance on Connecting Fleets.

Hydrogen fuel cell buses are refuelled in around 10 minutes and can be refuelled at a bus depot.

Alternatively, a hydrogen fuel cell bus can be refuelled at a central refuelling location, sharing hydrogen refuelling infrastructure with other transport modes.

Depending on the quantity required, hydrogen can be delivered to site in a liquified form by tanker trunk or as a compressed gas in cylinders or a tube trailer (a 40-foot trailer mounted on pressurised tubes).

Hydrogen can also be generated on-site through the installation of an electrolyser, using renewable electricity to produce hydrogen from water.

The role of local transport authorities

The Bus Back Better: national bus strategy for England required local transport authorities and operators to work together to produce Bus Service Improvement Plans (BSIPs) detailing how they would improve bus services.

As part of BSIPs, local transport authorities and bus operators were required to set out their ambitions to decarbonise the local bus fleet, with the expectation that the local bus fleet move to zero emission in the long run.

Local transport authorities can work to ensure that plans to decarbonise the bus fleets set out in BSIPs are aligned with wider decarbonisation plans.

The needs of bus and other mass transit providers should be considered as part of local authorityEVcharging infrastructure or local energy plans to ensure adequate, future-proofed provision is made.

Local transport authorities can also play a role in the procuring of zero emission buses. While in most cases zero emission buses would be procured by bus operators, local transport authorities that want to procure zero emission buses directly should consider procuring buses through Crown Commercial framework RM6060 and, from August 2022, RM6244.

Local transport authorities can also play a supporting role in infrastructure for zero emission buses. For electric buses, this could involve working with bus service operators to identify their needs, and with District Network Operators to identify the grid constraints and infrastructure upgrade requirements to recharge an electric bus fleet.

Facilitating access to funding

Local transport authorities can play an important role in securing access to UK government funding for zero emission buses and associated infrastructure.

There are currently no open funding schemes for zero emission buses.

The most recent UK government funding scheme, the Zero Emission Bus Regional Areas (ZEBRA) scheme, was open to local transport authorities in England (outside London). In line with previous funding schemes, theZEBRAscheme provided funding for up to:

A total of £269 million funding has been awarded for theZEBRAscheme in 2021 to 2022.

Almost £71 million funding was awarded to Warrington, Leicester, Milton Keynes, Kent and Cambridgeshire and Peterborough, in October 2021, supporting the introduction of up to 335 zero emission buses and associated infrastructure.

In March 2022, almost £199 million funding was awarded to Blackpool, City of York, Hertfordshire, Norfolk, North Yorkshire, Nottingham, Oxfordshire, Portsmouth and Hampshire, South Yorkshire, Southampton, Greater Manchester, West Midlands and West Yorkshire. This funding will support the introduction of up to 943 zero emission buses and associated infrastructure.

DfTwill provide information on how it will allocate funding for zero emission buses in the future in due course.