What is a Low Carbon Emission Bus?

Please note: The LCEB accreditation scheme has now been superseded by the Low Emission Bus accreditation scheme which compares GHG savings with conventional Euro V diesel buses rather than Euro III buses for the LCEB scheme.

A low carbon emission bus (LCEB) is a bus that is able to achieve the LCEB target for Greenhouse Gas (GHG) emissions, which is equivalent to a 30% reduction in its GHG emissions compared to the average Euro 3 diesel bus of the same total passenger capacity. A low carbon emission bus can use any technology or fuel.

The definition of a LCEB was developed by LowCVP members and is based upon the GHG emissions from the vehicle and from the fuel production. The definition of a LCEB is as follows:

"A Low Carbon Bus produces at least 30% fewer Greenhouse Gas Emissions than the average Euro 3 equivalent diesel bus of the same total passenger capacity. The Greenhouse Gas (GHG) emissions will be expressed in grams of carbon dioxide equivalent measured over a standard test, and will cover "Well-to-Wheel" (WTW) performance, thereby taking into account both the production of the fuel and its consumption on board".

The LCEB emission target is expressed as a function of total passenger capacity and is expressed as:

GHG (g/km) = 6.28 x total number of passengers + 502

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The Greenhouse Gases (GHG) of interest are Carbon Dioxide (CO2) Methane (CH4) and Nitrous Oxide (N2O). The relative "global warming potentials" for these 3 gases are 1:21:310 respectively. These emissions will be expressed in CO2 equivalent using the global warming potential to weight the emissions of each gas.

To qualify as a LCEB the bus must achieve the LCEB GHG target against a real life bus drive cycle such as the MLTB test cycle, or equivalent. If another test cycle is used this must be approved by the DfT in advance.

A vehicle can not qualify as a LCEB simply by using a fuel type which allows it to achieve a 30% reduction in its GHGs, unless the fuel it uses is biomethane.