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Fuel cell buses

bus-fuel-cell London's fuel cell bus trial has been extended London is taking part in a pioneering project to reduce air pollution and noise by testing thefirst generation of zero-emission fuel cell buses.

A cleaner, healthier future

This initiative is a key part of the Mayor of London'sTransport Strategy and Air Quality Strategy, designed to help give Londoners acleaner and healthier future.

Not only is the fuel cell bus trial a significant step towards achievingthis goal, it demonstrates that London is leading alternative forms ofpublic transport.

The initial trial was due to finish in December 2005 but due to thegood performance and reliability of the buses, it has been extendedby another year, with the vehicles now staying in operation untilJanuary 2007.

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Which route are they operating on?

The fuel cell buses will run on route RV1 between Covent Garden and Tower Gateway until January 2007. As conventional Citaro buses already operate on this route it will help in comparing the performance between fuel cell and diesel vehicles.

The fuel cell buses first went into service in January 2004 on route 25, with two buses in operation each day. The buses ran in addition to the normal service, as London Buses needed to assess how dependable they would be. The buses proved so reliable that when they were switched to RV1, all three buses were put into service and ran as part of the normal timetable.

How do fuel cell buses work?

Fuell cell diagram

Find out how fuel cells work (GIF 30KB)


Technical specification of the bus

Technical specification of the bus
Specification Value
Height 3.67m
Length 12 m
Width 2.55 m
Weight 14.2 tonnes (unloaded)
Seating 30 seated, 21 standees and 1 wheelchair
Fuel cell gross power: 250 kW (provided by 2 x 125 kW fuel cells)
Net shaft power: 190 kW @ 2100 rpm
H2 storage system pressure: 350 bar
H2 storage system capacity >40kg in 9 roof mounted pressure cylinders
Range 120 miles
Top speed 50 mph
Acceleration 0 - 30mph in 12 seconds
Interior noise 60 dBA

How is hydrogen made?

Hydrogen infrastructure
Hydrogen infrastructure

Hydrogen can be made from a number of different sources,including natural gas and the splitting of water into hydrogen andoxygen (electrolysis). The hydrogen for the London bus trials isproduced by steam reforming of natural gas. This is then liquefiedby cooling it down to a very low temperature. The liquid hydrogen isdelivered to BP's filling station at Hornchurch in east London whereit is stored under ground.

When the buses are being refuelled, the liquid is first vaporisedinto a gas before it is dispensed onto the bus and into pressurisedcylinders.

These are the cylinders you can see on top of the bus, along with the fuel cell system, coolersand other components.

Hydrogen infrastructure (PDF 124KB)

The trial

Nine cities in Europe originally took part in the fuel cell bus trial known as CUTE (Clean UrbanTransport for Europe), which ended in December 2005.

Fuel cell bus emitting water vapour
A fuel cell bus only emits water vapour

Seven cities are taking part in the one-year extension known asHYFLEET:CUTE.

These trials are the largest project of its type anywhere in theworld.

The reason it is so important is because local air pollution,greenhouse gas emissions and inner-city noise levels are majorcauses for concern.

The project brings together a large number of organisations, includingthe bus manufacturer, operating companies, hydrogen suppliers,fuelling and storage facilities, and universities.

It is part of the ongoing development of clean urban transport systems which combine energyefficiency with cost-effectiveness.

The fuel cell buses will be subjected to rigorous environmental, technical and economicanalysis, which will then be compared to conventional bus transportation.

By the end of the trial, London will have made a major contribution to a much-neededinitiative, the results of which are eagerly awaited by transport authorities and governmentsacross the globe.

The Mercedes Citaro buses, which have been built by Daimler Chrysler especially for thistrial, use the latest fuel cell and hydrogen technology.

Partners involved in the trial

The European Union

The European Union has co-financed the trial, with the support of the European CommissionDirectorate-General for Energy and Transport.

London Buses

London Buses, part of Transport for London, is responsible for achieving environmentaltargets and standards for the whole of London's bus fleet, as required by the Mayor's AirQuality Strategy.

First Group

The First Group operates around one sixth of the London bus network. The company's experience,support and expertise in transit management is crucial in ensuring the trial is conducted andassessed to rigorous standards.


BP is providing the hydrogen-refuelling facilities for the fuel cell buses. BP also provides therefuelling infrastructure for a number of the other cities in the HyFLEET:CUTE project and isdemonstrating a range of different hydrogen technologies in each location.


BOC is supplying the hydrogen technology to BP in London.

Energy Saving Trust

Energy Saving Trust supported the CUTE project through a grant from its New VehicleTechnology Fund programme (supported by the Department for Transport).

Daimler Chrysler

Daimler Chrysler has developed and manufactured the buses and will provide technicalsupport during the trial.

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