FAQ - Residual Mix
Find answers to Frequently Asked Questions on the Residual Mix.
Which types of emissions are accounted for in the Residual Mix?
The Residual Mix emission factors are based on EcoInvent emission factors per technology and per country. They can be found in the annex of the Residual Mix Report.
Only direct emissions are considered. No LCA calculations are performed, and biogenic carbon emissions are not included either.
Does the Residual Mix only contain fossil energy?
No. The Residual Mix serves as the cornerstone for a reliable energy disclosure system. All energy for which no GOs were issued, ends up in the Residual Mix. A country that relies for a large part on nuclear energy for their electricity production will in general also have a higher share of nuclear energy in the Residual Mix, provided that no nuclear GOs were issued. The Residual Mixes of different countries inside the calculation area interact to account for import and export of physical energy on the one hand, and of GOs on the other. This is why there may be a certain source share in the Residual Country, even though no electricity is generated from that source in that country.
In addition, expired GOs are also added to the Residual Mix, as they can no longer be used to disclose energy to a specific consumer. This is the main reason why there may be a fraction of renewable energy in the Residual Mix.
Which CO2 emission factor should I use?
We strongly recommend using market-based emission calculation for countries where a GO system is operated together with a Residual Mix.
If no GOs were cancelled for the energy for which the emissions are calculated, the Residual Mix emission factor should be used for reporting purposes. Use the emission factor for the country in which the energy was consumed.
If GOs were cancelled, the associated emissions should be used. The emission factor for electricity from renewable sources is zero.
Why is there no emission factor for some countries?
Until 2023, Austria and Switzerland had a "Zero Residual Mix", showing 0% for all energy sources, including the emission factor. From the 2023 Residual Mix onwards, this is replaced by "N/A".
The reason for this odd result is that Austria and Switzerland have implemented Full Disclosure. This means that all energy consumption must be disclosed towards end-consumers using cancelled GOs, renewable or otherwise. As such, there is no consumption left for which the energy source is undetermined, in other words, there is no need for a Residual Mix.
If you are reporting on emissions in such country, please refer to the source mix and associated emissions mentioned on the bill by the electricity supplier.
Does the Residual Mix account for imported/exported energy?
Yes. Imports from and exports to countries outside the calculation area are included in the calculation of the corrected production per country.
Imports/exports between countries in the Residual Mix calculation area are implicitly accounted for in the calculation.
How can there be a renewable share in a country's Residual Mix?
There are two reasons:
- Either, there is production of electricity from renewable sources that is included in the corrected production for that country, but for which no GOs were issued.
- Or there are expired GOs for electricity from renewable sources. Expired GOs are added to the Residual Mix.
Can I use data from the Residual Mix reports?
Yes, as long as you attribute AIB as the source for this data.
Can AIB anticipate next year's Residual Mix or make future projections?
No, unfortunately we can't. The Residual Mix depends on many, many factors, such as weather, availability of power plants, GO transfers, imports/exports,… this makes it impossible to anticipate possible evolutions in source shares and emission factors.
Does the Residual Mix calculation consider uncertainty in the emission factors?
No, it doesn't.
Does the Residual Mix consider transport/distribution losses?
Transmission and distribution losses are considered as consumption in the calculation. Therefore, they are not explicitly included in the Residual Mix. The TSO/DSO may choose to cancel GOs for such losses, or otherwise, their source mix and emissions are determined by the Residual Mix.
Can I access the data for the Residual Mix calculation of previous years?
Yes, please refer to the previous years in the navigation column on the left of the Residual Mix webpage.
Can I use the Total Supplier Mix for carbon emissions reporting?
If no GOs were cancelled for your client's/company's consumption, you should use the Residual Mix. If you do cancel GOs, you use them to determine the source mix and the associated emissions.
The Total Supplier Mix gives an average source mix for all consumption in one country. Using the Total Supplier Mix instead of the Residual Mix for reporting purposes would cause double counting of the renewable attributes.