How we calculate carbon emissions

The model calculates CO2 emissions for the current year and the scenario year. The CO2 emission for the year 1990 is a fixed number taken from area data.

The CO2 calculations are used to determine the amount of CO2 that is emitted in the area. This calculation is based on the area's primary demand, and uses the emission factors of energy carriers to determine the total CO2 that is emitted from the energy carriers. The total CO2 emission of these carriers determines the total CO2-emission of the area.

There are two cases in which the calculation has an exception:

  • CO2 Capture and Storage

    Some converters can capture and store CO2, preventing it's emission. The percentage of this capture is stored as a converter attribute.

  • Non energetic energy use

    Some of the energy used in areas is not used in an energetic fashion, emitting CO2, but non-energetic, where the CO2 is maintained in a product. Plastic production is an example where the oil is not emitting its CO2, as the carbon is in part 'stored' in the plastic itself. Of course both the energy required in the production process, and the incineration of the plastic both are processes in which CO2 is emitted.

General calculation method

The model calculates CO2 emissions associated with the energy output of a specific converter in a bottom-up fashion: Each converter 'asks' the converter one level higher what the CO2 emissions of that converter's energy output are and takes his share. This process continues until it reaches the primary converters, where the CO2 emissions are calculated on the basis of the energy carriers and emission factors. In this process CO2 emissions related to distribution and conversion losses etc. are included.

The emission factors for energy carriers depend on the mix of origins for those carriers. For example, coal from different regions of origin has different carbon content and hence emission factors differ. The mix of origin is set to the current mix for a country. For the Netherlands, the future mix can be changed by the user in the 'Fuel chain emissions' section under Supply. The default emission factors can be found in the table below.

The emission factor for imported electricity is assumed to be the same as the regional average. (This assumption is expected to change in the near future).

For converters that have CO2 capture and storage (CCS) abilities, the associated CO2 emissions of its energy output are reduced by the capture factor. The capture factor of CCS technologies in the model is 85%.

Because the CO2 emissions calculation is based on energy flows, the model calculates only energetic CO2 emissions. This does not include CO2 emissions from final non-energy consumption, fugitive emissions, industrial process, solvent and other product use, agriculture, LULUCF (Land Use, Land Use Change, and Forestry), and other. For more information on these definitions click here.

Energy CarrierEmission factorSource
kg CO2 per MJ
Crude oil0.073281826
Natural gas0.056060597
Uranium (nuclear energy)0
Waste (independent of biogenic share)0
Biomass (solid, liquid, and gaseous)0
Renewable electricity (wind, solar etc.)0
Renewable heat (Ambient heat, solar thermal, geothermal)0
Imported electricityAverage of current region

Note: Steam & hot water (monetized heat) is not a primary energy carrier, it is always produced from some other form and cannot be imported.

Dashboard CO2 calculation

In the dashboard CO2 calculation we calculate the CO2 emissions associated with all final energy consumption in the area. Therefore these numbers do not include CO2 emissions from the conversion sector within the area that is associated with exported energy (currently only electricity). CO2 that is emited outside the area to produce electricity that is final energy consumption in the area is included. Note that this method deviates from the standard way CO2 emissions are measured, as normally any emission outside the target area would not be included, whereas all energetic emissions in the area would be.

Table "CO2 emissions with im- or export"

This table can be loaded anywhere in the ETM by clicking 'change' in any chart and selecting it from the list. It shows the following for 1990, 2010 and the future year 20xx:

  • The emission including emission for exported electricity (actuals)
  • The emission for exported electricity (difference, export is negative)
  • The emission for supplying only the inland final consumption (With im- and export)

Technical data

  • The amount of carbon capture and storage (CCS) for every converter is stored in attribute CO2_free. Currently the value is 100% for all non-energetic consumption, 85% for all CCS power plants, and 0% for everything else.

  • For each converter the ETM can calculate specifically how much CO2 is emitted in the scenario.

This makes use of the method "weighted_carrier_co2_per_mj" which is calculated for each converter.