European Residual Mix
The residual mix is a key tool for avoiding double counting of the same amount of electricity from a certain energy source.
This is explained in detail in the Best Practice Recommendations from the RE-DISS project.
AIB is updating the Residual Mix calculation methodology to overcome issues with the previous methodology. The reasons for change and the new methodology are downloadable from this page. This methodology was subjected to an initial round of consultations in December 2019, and further comments to this methodology were invited by 15th March 2020. A webinar was held on 10th March 2020 to present this methodology and providing occasions for questions, and presentations given are downloadable below:
AIB has published the Residual Mixes and European Attribute Mix of 2019. The calculation was carried out by Grexel Systems Ltd on behalf of AIB, assisted by Ostfoldforskning and Ecoinvent.
A residual mix represents the mix of uncertified electricity and is a key ingredient of a reliable disclosure system. A residual mix is needed for reliable disclosure of electricity consumption where Guarantees of Origin (or in some cases other legally accepted tracking instruments) are not used. Due to the international nature of both the power market and the Guarantee of Origin (GO) market, centrally calculated residual mixes and the European Attribute Mix (EAM) are needed. Energy authorities use the results of the calculation either directly or to calculate the residual mix for their respective country using national rules.
The first residual mix calculation with the revised Issuance Based Method is now complete. The key motivation for the methodology change was to remove the systemic error due to the use of the Guarantee of Origin (GO) Import and Export volumes, which include trading as well as transfers for end-use. A comparison of the last three years' residual mix results is shown at the end of the report, in Figure 10 and Table 7. As expected, the residual mixes of Norway and Belgium have changed a lot, along with some of the other countries, although the residual mixes of others have not changed at all. A key difference between the old and new methodologies is that it was difficult to identify the precise impact of trading activity, but this is no longer the case (for example, the Norwegian residual mix of 2017-STB was very similar to the new Issuance-based figure).
As expected, the deficit from the European Attribute Mix was tens of TWhs (70 TWh) higher than the surplus to it. This is due to the use of Issuance volumes instead of Cancellations for domestic residual mixes in an environment where the GO coverage in Europe is expanding. The expansion means that Cancellation volumes lag behind Issuance volumes - which can be seen clearly in the AIB activity statistics. All national attribute deficits are nevertheless filled with EAM, which means that attributes from future EAM are used, but according to the current mix. Over the years, the situation would be balanced if the Cancellation volumes grow higher than the Issuance volumes. Nevertheless, with the low amount of Renewables in the EAM, this is a conservative approach to make the annual calculations possible.
Highlighted results from the calculation:
- The European Attribute Mix for 2019 is 4.44% renewable, 42.02% nuclear and 53.53% fossil. The change to last year is (respectively) +2.00%, +5.06% and -7.07%.
- The volume of reliably-tracked electricity origin grew from 988 TWh to 1068 TWh. However, a big part of this change is due to the use of Issuance volumes instead of Cancellation volumes.
- The share of untracked consumption has continued to decrease and is now 67.3% (70% in 2018). The methodology change did not have any effect on this. In 2019, the lowest untracked consumption (apart from full disclosure in Austria) was Luxembourg (9.40%), Ireland (11.33%), Sweden (12.63%) and Switzerland (12.80%). Low untracked consumption suggests high consumer demand for origin tracked electricity, but it also shows national regulation choices.
- Contrary to the EAM, on average the residual mixes showed a decrease in the renewable share: 9.3% renewable, 35.8% nuclear and 54.8% fossil. For 2018, the figures were respectively 12.4%, 33.0% and 54.6%.