Blog Series Emissions #2 Carbon Calculation

Emissionsberechnung_80x80In our last post we emphasized the importance of carbon reduction. Now, we dive into carbon calculation and go further into details of emission data standards and approaches. The described possibilities of emission calculation are available with PTV xServer.

Emission calculation

For calculating emissions two main influencing factors are important:

  • Vehicle-specific factors as for example vehicle type, fuel type, fuel consumption
  • Route- specific factors like heights, distance, speed, network level etc.

These factors can be different from area to area; country to country or continent to continent. Therefore, area-specific data standards have been developed by various institutes and governments to provide the most suitable factor set.

Emission data standards

Emission data standards include a set of influencing factors and parameters: reference data, default values for consumption, emission factors, vehicle types etc. National characteristics and standards play an important role. Different road and vehicle types as well as regional landscape differences lead to continental/country specific emission factors and consumption values. The data standards vary a lot, support different vehicle types, contain more or less factors and offer different result sets. If you want to meet national requirements you have to chose a suitable data standard. PTV xServer provides the following data sets:


  • HBEFA 3.2 (Europe): The Handbook of Emission Factors for Road Transport (HBEFA) was originally developed on behalf of the Environmental Protection Agencies of Germany, Switzerland and Austria. In the meantime, further countries (Sweden, Norway, France) as well as the JRC (European Research Center of the European Commission) are supporting HBEFA.
  • CEN 2011/2012 (Europe): The CEN standard EN 16258 is a European standard specifying general principles, definition, calculation methods and data recommendations, with the objective to promote standardized, accurate, credible and verifiable declarations, regarding energy consumption and emissions related to any transport service.
  • CO2 Decree France 2011 (France):  Since 2013, all commercial transports (trucks, taxis, ships, trains, etc.) starting or ending in France have to report their CO2 emissions. In other words: a company carrying out a transport from or to France has to report their emissions.
  • UK DEFRA 2014 (UK): Government conversion factors for greenhouse gas reporting. These factors are suitable for use by UK based organisations of all sizes, and for international organisations reporting on UK operations.


  • Australia NGA 2011: Emission calculation for transports in Australia have to be in accordance with the National Greenhouse Accounts (NGA) factors published by the Australian government.
  • COPERT Australia 1.2: COPERT Australia is designed to be used for road transport emission inventories across Australia. It is the result of a joint effort of EMISIA and the Queensland Department of Science.
Emission calculation with UK DEFRA 2014 and COPERT Australia 1.2 will be available with the new PTV xServer 1.20.1 release in August this year. Further information will follow in our webinar about the release on 15th of September, 2:00 pm. Details about the webinar will follow in this blog.

Emission calculation approaches

As described above, vehicle- and route-specifics are needed for emission calculation. One important vehicle factor is the fuel consumption. It is treated different in different data standards. This is shown later. All other specifics are reflected in factors provided by the data standard.

In simple terms, emissions are calculated by multiplying fuel consumption values with emission factors. Depending on the chosen emission data standard for determining the emissions, consumption and factors are both included in the data or are provided separately. Two basic approaches are distinguished according to this difference: Comprehensive Approach and Factor-based Approach


The Comprehensive Approach includes both, consumption default values and emission factors. Therefore, no own average fuel consumption values have to be determined for calculation. Additional, it also takes height data into account. HBEFA and COPERT Australia are standards of the comprehensive approach.

The Factor-based Approach provides emission factors. Consumption values are chosen by the user and can be based on own average fuel consumption or different recommended consumption default values provided for example in the PTV xServer manual. Australia NGA 2011, CEN 2011/2012, CO2 Decree France 2011 and UK DEFRA 2014 are standards of the factor-based approach.


  • There are different emission data standards available providing the data basis for calculating emissions for specific areas and countries. Depending on your activities, your fleet and legal requirements you have to choose a suitable data standard.
  • PTV xServer supports various data standards for Europe and Australia.
  • The data standards can be factor-based or comprehensive. In the case of factor-based approaches you have to determine your own consumption values (or use default values proposed by different institutes) whereas comprehensive approaches already include default consumption values.
  • PTV xServer allow the calculation of both approaches.

BlogSeriesGot an overview of the calculation approaches and want to get started calculating? Don’t miss our third emissions post next Wednesday about generating reports.Get to know the possibilities of Carbon Reporting with PTV xServer.

By Hannah Esswein

Technical Product Manager for PTV xServer