Primary demand

Primary energy is energy found in nature that has not been subjected to any conversion or transformation process. For quantitative applications such as the Energy Transition Model (ETM) and Energy Balances we need to define the primary energy more precisely. The conventions in the ETM are consistent with International Energy Agency (IEA) and Eurostat (EC) conventions unless otherwise specified.

Primary energy calculation method

The model calculates primary consumption associated with the output of a specific converter in a bottom-up fashion: Each converter 'asks' the converter one level higher what the primary consumption of that converter's output is and takes his share. This process continues until it reaches the primary converters. At the primary converters, the primary consumption is determined using the physical content method. Hence the associated primary consumption can be calculated for every converter, including those that represent non-energetic consumption (for example feedstock in the chemical industry) and those that export energy (currently only electricity is exported as a carrier where transformation losses occur).

"Energy use" in the dashboard

Main article: Dashboard

The "Energy use" in the dashboard is the primary consumption associated with total (inland) final consumption. This includes primary consumption that results from final non-energy consumption (for example feedstock in the chemical industry). It does not include primary consumption that results from exports. This also means that, contrary to IEA/EC conventions, the losses which are typically incurred in the conversion sector are only included for the part of the inland final consumption, not for the exports.

Physical content method

We determine the primary energy equivalent of an energy flow by calculating the physical energy content of the primary energy form. This method is called the 'physical content method' (as opposed to the 'partial substitution method').

  • For combustible fuels (coal, oil, gas, biomass, waste and derived products) the primary energy form is the fuel itself. The physical energy is calculated on net calorific value basis.
  • For nuclear, solar-thermal, geothermal, and heat-pumps; heat is the primary energy form. The physical energy calculation is different for these carriers (see table below)
  • For hydro, wind, tide/wave/ocean and solar photovoltaic; electricity is the primary energy form. The physical energy is equal to the gross output of electricity.

Physical energy calculation

TechnologyPrimary energy formCalculation IEA/ECCalculation ETM
Combustible fuels (coal, oil, gas, biomass, waste and derivatives)Fuel itselfHeat of combustion on a net calorific value basis (also known as lower heating value)Idem
NuclearHeat3.03 x gross output of electricity (which assumes a 33% efficiency)3.125 x (assumes 32 % efficiency)
Solar thermalHeatOutput of heat. Note: only solar heat from flat plate collectors and solar thermal electric plants is counted, not passive heating of houses etc.Idem
Geothermal heatHeat2 x heat outputOutput of heat
Geothermal electricityHeat / Electricity10 x electricity outputGross output of electricity
Heat pump (ambient heat part)HeatUseful heat output - Electricity input. Note: only ambient heat for heat pumps that deliver monetized heat is counted; ambient heat for heat pumps in for example households or industry is not counted at all.All ambient heat input to heatpumps is counted, also for example in households or industry. The calculation is idem.
Hydro energyElectricityGross output of electricityIdem
Wind energyElectricityGross output of electricityIdem
Tide/wave/oceanElectricityGross output of electricityN/A
Solar PhotovoltaicElectricityGross output of electricityIdem

General information on primary energy can be found here.