This category allows users to calculate greenhouse gas emissions from a ship journey from indicating the ship's size. The methodology follows the latest Defra emission factors and advice.
How to use this category
There is one drill-down in this category. Use the drill-down type to select the type of ship used from the following options.
- ferry - average RoPax ferry (roll-on roll-off ferry with additional passenger capacity)
- by foot - pedestrian journey only
- by car - car journey only
The distancePerJourney must then be entered as a profile item value. There are three further optional profile item values, isReturn, numberOfJourneys, numberOfPassengers. The isReturn profile item can be set to either true or false (false by default), if true the algorithm doubles the numberOfJourneys. The emissions for one journey for one person are multiplied by the numberOfJourneys and numberOfPassengers (each have a default of 1) to give the total emissions for the people and journeys the user wishes to calculate for.
CO2eEmissionFactor = CO2EF + CO2eEFForN2O + CO2eEFForCH4
CO2e = CO2eEmissionFactor * distancePerJourney * numberOfJourneys * numberOfPassengers
The algorithm returns a value of kgCO2e for the selected journey. This value includes contributions from carbon dioxide, nitrous oxide and methane.