Generic minibus transport

The category /transport/minibus/generic contains data associated with the greenhouse gas emissions of minibus vehicles sourced from the VCA.

Emissions calculations within this category use distance-based emissions factors, although users have the option of using either established generic emissions factors or deriving their own from details of their vehicles fuel consumption together with generic fuel-based emissions factors. (This category functions similarly to the Generic car transport category).

Selecting vehicle type

To use this category, specify the vehicle fuel type and size using the fuel and size drill options. The category contains the following four representative vehicle types:

• diesel, mpv - Multi-purpose diesel vehicle based on Ford Tourneo Connect
• petrol, mpv - Multi-purpose petrol vehicle based on Vauxhal Zafira
• diesel, minibus - Diesel minibus based on Ford Transit Connect
• petrol, minibus - Petrol minibus based on Mercedes Benz Viano

Calculating by fuel consumed

To make calculations according to the quantity of fuel consumed, users need only specify the fuel quantity using the fuelConsumed profile item value. The returned value represents CO₂ emissions associated with the quantity specified. This is the most accurate method for determining emissions since it makes no assumptions or generalisations regarding the performance, context or efficiency of the vehicle. This calculation method takes precedence over distance-based calculations (see below) - i.e. this calculation will be performed whenever the fuelConsumed profile item value is specified.

Calculating by distance

To calculate according to distance, users need to specify at least a distance value, and select between calculations based on either established, generic emissions factors or those derived from fuel consumption data. Occupancy can be specified (see below) but defaults to a sensible value if not set.

Using established emissions factors

To use established emissions factors (sourced from VCA, users need only set the distance profile item value (although several further specifications may be made in order to establish more accurate results). If the distance profile item value alone is set, the returned amount represents CO₂ emissions associated with minibus travel according to the distance specified.

Deriving emissions factors from fuel consumption

Instead of using pre-established emissions factors, users can opt to give a vehicle's fuel consumption. This can either be a user's own estimate (self-calculated or perhaps obtained from their on-board computer) or one provided by the manufacturer, and results in a more accurate estimate of the kg CO₂ emitted. The specified fuel consumption value is used in conjunction with data on the carbon intensity of the respective fuel type taken from The category /home/energy/quantity to obtain a distance-based emissions factor according to:

Factor_{(mass CO2 per distance)} = fuel carbon intensity_{(mass CO2 per volume)} / fuel consumption_{(volume per distance)}

To specify either a manufacturer or self-calculated fuel consumption rate, set either the fuelConsumption or fuelConsumptionOwn profile item values. If the former (i.e. manufacturer) is specified, Discover will inflate the value by 15% to account for real world usage. Next, specify the distance travelled using the distance profile item value.

Emissions factor modifiers

Emissions factors can be further tweaked to provide more accurate calculations by setting several other profile item values which represent factors affecting vehicle fuel consumption. These can be accessed as follows:

• set tyresUnderinflated = 'true' to specify under-inflated tyres (increases emissions by 1%)
• set airconFull = 'true' to specify regular use of air conditioning (increases emissions by 20%)
• set airconTypical = 'false' to 'switch off' the typical-air-conditioning-usage assumption (decreases emissions by 5%)
• set ecoDriving = 'true' to specify fuel saving driving practices (e.g. avoiding excessive speed, harsh acceleration and braking; decreases emissions by 10%)
• set regularlyServiced = 'false' to 'switch off' the regular-vehicle-service assumption (increases emissions by 4%)

Note: these are irrelevant and therefore ignored if the user has supplied their "own" estimate of fuel consumption, and only apply if using established, generic emissions factors or an emissions factor derived from manufacturer fuel consumption data.

Occupancy

Users can set multiple occupancy for large goods vehicle travel, which 'shares' the vehicular emissions across all passengers. To specify the number of occupants set the occupants profile item value. If no value is set, the calculation will be made on the basis of a single occupant (i.e. the driver) and simply represents emissions for the entire vehicle journey(s).