AIB CADv2025 - methods and changes
The updates described in this article will go live on Dec 11, 2025.
Summary
| Publisher | Association of Issuing Bodies (AIB) |
| Full name | Association of Issuing Bodies - European Production and Residual Mixes |
| Description | Electricity Emission Factor set published by the Association of Issuing Bodies where the production mix, consumption mix as well as the residual grid mix (for untracked consumption) is calculated. |
| Version nr. | CADv2025 |
Source documents
Note that the year-suffix (e.g. y2025) in the versions refers to the year of in which the source document was published. This is different from the internal naming AIB uses, which refers to the year on which the data is based. The source referred to as AIB y2025 here lives on the url www.aib-net.org/european-residual-mix/2024 and is downloadable in a pdf titled Results of the calculation of Residual Mixes for the calendar year 2024.
Methodology readout notes
General Methodology
The AIB dataset used for CADv2025 was downloaded directly from the official source in spreadsheet format where available, if not from the published PDF.
Emission factor values were read out from the country tables for CO₂ only (no greenhouse gas split is provided in the source). All original values were expressed in gCO₂/kWh and converted into other units where needed.
The allocation of mix type and reporting split (market-based vs location-based) was based on the definitions for each of the mixes types made available by AIB.
The full readout mapping is summarised in the table below:
| Mix type | Market-based | Location-based |
|---|---|---|
| Country average mix | Supplier Mix | Production Mix |
| Residual mix (no green electricity contract) | Residual Mix | Production Mix |
| Green electricity contract | Set to 0 | Production Mix |
Justification:
- Production Mix is the only value in the AIB source that does not reflect market mechanisms and is therefore used for location-based reporting.
- Supplier Mix considers the average mix in a country taking into account GO trades and is therefore used to represent average national emissions under the market-based method.
- Residual Mix intrinsically represents the energy left in a region after GO's are taken into account (after Green electricity is sold off). This maps on Market based Residual Mix per definition.
- Green electricity values are set to zero emissions under market-based rules, while under location-based accounting the production mix is mapped.
Approximation of Generation and Transmission & Distribution (T&D) Emissions
As the AIB currently does not publish lifecycle stage emission factors, upstream generation and T&D emissions are estimated via a loss factor approach (GHG Protocol Scope 2 Guidance, p. 96). A fixed proportional increase was applied to the core electricity production emission factor:
| Lifecycle stage | Loss factor |
|---|---|
| Transmission & Distribution | 10% |
| Generation (fuel-cycle) | 30% |
These ratios were applied uniformly across all countries and years.
Justification:
- AIB published lifecycle factors in 2018; 30% reflects the rounded mean ratio for upstream emissions.
- Comparison with IEA dataset values showed similar ratios: both 10% (T&D) and 30% (generation) represent mean + 1 standard deviation, making them a conservative (slightly overestimating) estimate.
Approach to base years
As of CADv2025, Carbon+Alt+Delete has updated the application period definition for the AIB dataset. We now consider electricity emission factors released in year Y valid for application in year Y itself, pinning the application year to publication date rather than the base data year.
This approach eliminates the need for retrospective electricity corrections (year Y-1), aligns with databases that have less explicit methodological delays, and reduces inventory impact during annual updates.
In practical terms, this means that the factors published in the AIB y2025 release are considered valid for reporting year 2025. Values for reporting years 2024 and 2023 continue to use the originally attributed publications (AIB y2024) and do not change in this update.
Only reporting year 2025 values change in this release. As of the next update cycle, only the factor for reporting year 2026 will update.
Update cadence
Expected update dates will be added later.
Data considerations and notes
General content notes
- Country average mix should only be used to represent the actual averaged-out consumption across a population. For example, in product use. It should not be used to reflect "unclear contract attribution" as this will lead to double counting of the energy mix.
- For any electricity contract with no certain green Guarantee of Origin, the residual mix variant should be used to respect the attribution logic and avoid underestimating scope 2 emissions.
- In countries with full disclosure regimes, such as Austria (since 2017), Switzerland (since 2022), and The Netherlands (since 2024), the residual mix becomes ill-defined and should not be used. See https://www.aib-net.org/faq/residual-mix for more information.
- This dataset has no greenhouse gas split available, and only reports CO₂ factors.
- This dataset does not contain information about the bioCO₂ produced by electricity generated by biofuels.
- AIB factors show high fluctuations between publication years, often >10%. To avoid multiple correction rounds, C+A+D uses the Y-1 factor in year Y (see Approach to base years). Consider the temporal representativeness uncertainty associated with this.
Emission factor value flags
In countries with full disclosure regimes (Austria since 2017, Switzerland since 2022, The Netherlands since 2024), the residual mix is presented as zero for years the regime was active. In those circumstances, the residual mix is non-existent and ill-defined, so these value should not be used as a 0.
The production mix for Norway is 0 in 2023, resulting in 0 kgCO2/kWh location-based emissions for all details.
What's new in CADv2025
Important keyword changes
For Austria, Netherlands and Switzerland, the detail "Residual mix" is renamed into “Residual mix (not applicable in full disclosure regime)” to avoid any accidental usage of residual mix term in the disclosure regime (see above).
Important methodological changes
New approach to base years, see Approach to base years.
Factors for reporting years 2024 and earlier are unchanged in this update. Reporting year 2024 factors continue to use the value from the AIB y2024 publication. Reporting year 2023 and earlier factors use the values from AIB y2024, AIB y2023 etc. publications with a Y-1 shift.
Factor changes with CADv2025
Significant changes include:
- Switzerland - Country average mix: +283% (from 1.5 kg to 5.7 kg/MWh)
- Luxembourg - Country average mix: −76% (172 → 41 kg/MWh)
- Germany - Country average mix: −55% (96 → 42 kg/MWh)
- Netherlands - Country average mix: +47% (171 → 251 kg/MWh)
- France - Country average mix: −42% (33.6 → 19.5 kg/MWh)
- Austria - Country average mix: +41% (64.7 → 91.3 kg/MWh)
- Italy - Country average mix: −35% (431 → 279 kg/MWh)
- Denmark - Country average mix: −30% (330 → 243 kg/MWh)
- United Kingdom - all location-based: −23% (193 → 184 kg/MWh)
- Netherlands - residual mix: 0 kg/MWh, reflecting non-applicability under full disclosure regime
- Broad sub-20% shifts observed for other countries
Other changes
Emission factors for Norway no longer appear twice in the library.
Updated Comments for Austria, Switzerland, and The Netherlands.
External links
IEA 2024 Database documentation
IEA 2024 Upstream Emission Factors Documentation