In order to estimate the Primary Energy Factor and CO2 Equivalent Emission Factor of cogeneration units in previous FfE studies the "Replacement Mix" approach was introduced. It can be considered a simplified marginal approach, assessing the environmental effects of the electricity generation mix which can be displaced by additional (marginal) electricity generation from cogeneration plants. In this study the approach is developed further, especially considering the employed data set, accounting of electricity imports and the inclusion of grid losses as well as the upstream chain.
In the study, Primary Energy Factor and CO2 Equivalent Emission Factor values are calculated for each EU-28 country based on the displacement mix, an electricity generation mix that excludes the priority-of-dispatch generation, e.g. non-dispatchable renewable electricity. Because electricity generation from non-dispatchable renewable energies such as wind, solar and run-of-river has the lowest variable costs, these feed-in as much electricity as they generate. Also cogeneration plants are excluded in the displacement mix as it is assumed, that they would not be displaced by new cogeneration plants. All other plants are included in the displacement mix according to their share in the overall generation composition by country.
The results for the EU-28 are visualized in figure 1. Details are described in the report.
Figure 1: Resulting Primary Energy Factors for electricity of the EU-28 including grid losses according to displacement mix methodology based on lower heating value
Figure 2: Comparison of the generation with the displacement mix in the European Union and the resulting Primary Energy Factor and CO2 Equivalent Emission Factor resulting from the displacement mix