Blog Series Emissions #3b Carbon Reporting

Emissionsberechnung_80x80In our last post you learned about carbon reporting with PTV xRoute and comprehensive approaches. Today, we focus on factor-based approaches and their calculation with PTV xRoute.

Factor-based approaches contain emission factors but no consumption values. Consumption values are chosen by the user and can be based on own average fuel consumption or different recommended consumption default values. See our post about emission standards for details. CEN and UK DEFRA are examples for this type of calculation approach.

What you need to have

  • PTV xRoute Server
  • PTV Map including the area where emissions are calculated
  • In case of calculation according to factor-based data approaches there is no specific data or license needed.

What you need to do

You need to send a PTV xRoute request for either the method calculateExtendedRoute or calculateAdvancedTour. The route must at least contain two waypoints and you have to specify the data standard type you want to use e.g. CEN_2012. Additionally, you set the consumption of your fleet or the expected consumption for the route as average or the current measured value. This is described in the proceeding sample request. As a result you receive the values for the available greenhouse gases supported by the standard.

Sample Request

In the PTV xRoute request you specify at least two waypoints and your vehicle routing profile. Set the cenVersion attribute in the ResultListOptions element according to the emission standard you want to use. Don’t be confused about the naming. Here, you can also choose other emission standards than CEN although it is called ‘cenVersion’. All comprehensive approaches will be set via this cenVersion even if they are not CEN. If you want to use CEN 2012, as done in this sample, set the cenVersion to CEN_2012.

...  
"details": {
    "cenEmissionConfiguration": {
      "$type": "CENEmissionConfiguration",
      "fleetSpecificAverageFuelConsumption": "8.7",
      "cenVersion": "CEN_2012"
    },
    "emissions": {
    "$type": "EmissionType",
    "emissionLevel": "BASIC"
    }
  }
}

The fuel consumption is also specified in the request within the “cenEmissionConfiguration”. There are three types of consumptions available which can be set in the request:CENEmissionConfig

In this example the fleet specific average fuel consumption of 8.7 l/100km is used.

The granularity of the emission information returned is handled the same like for comprehensive approaches. There are three emission levels available:

  • BASIC, if you only need the total emissions of the route
  • STATIONS, if you want to obtain the emission per part of the route
  • SEGMENTS, if you additionally want to obtain the emissions per Segment

In the sample request, the level BASIC is used. Therefore, the response contains the total emissions summed up for the entire route.

Sample Response

The listed values in the response depend on the emission standard. Have a look at the documentation for CENEmissions2011, CENEmission2012, CO2DecreeFrance2011, AustraliaNGA2011 or UKDEFRA2014 for detailed information.

The response of the sample request contains several sections:

  • The first general section “Emissions” with the values of the greenhouse gases
  • The second section “vehicleSpecific”: The emissions based on the vehicle specific fuel consumption. The fuel consumption of the vehicle is set by request or in the vehicle Profile.
  • The third section “fleetSpecific”: The emissions based on a fleet specific fuel consumption.
  • The fourth section “basedOnHBEFA”: The emissions based on the fuel consumption as it was calculated by HBEFA 3.1 or higher. The values based on HBEFA 2.1 will not be correct. If you do not want to calculate emissions based on HBEFA, use HBEFAVersion NO_HBEFA.

If you would have provided other consumption values for the route or the actual fuel consumption in the request, there would also be sections for their values in the response:

...
"emissions": {
      "$type": "Emissions",
      "hydrocarbons": 0.26766972687899987,f
      "methane": 0.02248425285899999,
      "hydrocarbonsExMethane": 0.24518547402000002,
      "carbonMonoxide": 15.616740881359998,
      "carbonDioxide": 4.230746730810099,
      "sulphurDioxide": 0.186552613168,
      "nitrogenOxides": 0.8886238383990003,
      "nitrousOxide": 0.053431981629999965,
      "ammonia": 0.5341401447849998,
      "benzene": 0.03460969095000001,
      "toluene": 0.02489327998599999,
      "xylene": 0.020610580044,
      "lead": 0,
      "particles": 0,
      "fuel": 1.3325186338024397
    },
    "cenEmissions": {
      "vehicleSpecific": {
        "$type": "CENEmissions2012",
        "energyUseTank2Wheel": 66.26502399999997,
        "energyUseWell2Wheel": 77.58358399999999,
        "energyUseWell2Tank": 11.31856000000002,
        "co2eTank2Wheel": 4.9801664,
        "co2eWell2Wheel": 5.926809600000004,
        "co2eWell2Tank": 0.9466432000000041,
        "fuelConsumption": 1.5331504000000014
      },
      "fleetSpecific": {
        "$type": "CENEmissions2012",
        "energyUseTank2Wheel": 72.06321359999998,
        "energyUseWell2Wheel": 84.37214759999998,
        "energyUseWell2Tank": 12.308933999999994,
        "co2eTank2Wheel": 5.415930960000001,
        "co2eWell2Wheel": 6.445405439999999,
        "co2eWell2Tank": 1.029474479999998,
        "fuelConsumption": 1.6673010599999993
      },
      "basedOnHBEFA": {
        "$type": "CENEmissions2012",
        "energyUseTank2Wheel": 42.89876173256145,
        "energyUseWell2Wheel": 50.226189978806374,
        "energyUseWell2Tank": 7.327428246244928,
        "co2eTank2Wheel": 3.224068428347786,
        "co2eWell2Wheel": 3.836907881670089,
        "co2eWell2Tank": 0.6128394533223032,
        "fuelConsumption": 0.9925334624459093
      },
      ...

In our PTV xServer Codesample Browser you can find some examples for emission calculation according to Factor-based ApproachesThere, the result is visualized like this:

EmissionCalcCodeSampleBrowser_CENinput

EmissionCalcCodeSampleBrowser_CENoutput

Conclusion

  • PTV xRoute Server allows calculating emissions for the methods calculateExtendedRoute or calculateAdvancedTour
  • For factor-based approaches no additional data and licensing is required
  • In the request you specify route, vehicle type and emission standard type and for factor-based approaches the fuel consumption
  • As a response you receive the values for the available greenhouse gases supported by the standard as provided in the request for the given consumption value type: fleet, route or actual consumption specific.

An use case documentation can be found here. Please remember that UK DEFRA is only available with the new PTV xServer 1.20.1 release, which has just been released yesterday. With this, the use case description will be updated containing the UK DEFRA information and other improvements. Just take another look on the use case docu right now.

Further links:

BlogSeriesThis was the last post of our “Emission Wednesday Series”. We hope you did get an impression of emission calculation with PTV xRoute. A short summary of all topics will follow next week.