Glossary What are emission factors?

Emission factors (EF) for fossil and renewable energy sources summarise the total emissions along the respective energy supply chain. In addition to the direct emissions (EFDirect) from plant operation, they also include the indirect (upstream) emissions, i.e. all relevant emissions from the extraction, processing and transport of the fuels to the manufacture of the plants (EFUpstream) and the use of externally sourced auxiliary energy (EFAuxiliary) in plant operation. It should be emphasised that the conservatively selected emission factors represent neither actual individual plants nor the current state of the art, but rather the average number of plants in Germany.

The data is taken from the National Emissions Inventory (ZSE), various life cycle assessment databases (Gemis) of Directive 2009/28/EC and from the IFEU report on "Updating the input data and emission balances of key biogenic energy utilisation pathways (BioEm)" (IFEU, 2016). In the case of the emission factors for externally sourced auxiliary energy, an estimate is made based on official statistics (StBa, 2018), among other things. In the case of biofuels, the emission factors are largely determined by the raw materials used in production, the proportions of which are derived from the evaluation report in accordance with Biokraft-NachV/BioSt-NachV of the Federal Office for Agriculture and Food."
Source: Emissions balance of renewable energy sources (umweltbundesamt.de) S.18.