European Resource Adequacy Assessment
What is it?
Mandated by the 2019 Clean Energy Package, the European Resource Adequacy Assessment (ERAA) is ENTSO-E’s annual assessment of the risks to EU security of electricity supply for up to 10 years ahead.
Following the approach of the ERAA methodology by ACER in October 2020, ENTSO-E must carry out an annual ERAA to assess whether the EU has sufficient electricity resources to meet its future demand.
At national level, Member States set their own electricity reliability standard to indicate the level of security of electricity supply they need.
At European level, ENTSO-E’s ERAA aims to identify potential electricity resource adequacy concerns in the EU and provide an objective basis for assessing the need for additional national measures ensuring security of electricity supply such as the introduction of temporary capacity mechanisms.
European Resource Adequacy Assessment
What is the role of ACER with respect to the ERAA?
ACER has been closely involved in the development of the current EU adequacy framework and its implementation. ACER
- approves the methodologies associated with the ERAA (see below)
- assesses ENTSO-E’s annual ERAA that is subject to ACER’s approval. Analysis includes the relevant scenarios, assumptions and results (see below the ACER decisions on the ERAAs)
- contributes to the discussions around ERAA and guides ENTSO-E to deliver a robust assessment in the interest of EU security of electricity supply.
European Resource Adequacy Assessment
ERAA 2023: Track ACER's involvement
The image below illustrates how ACER, throughout the year, engages with ENTSO-E and other stakeholders on ERAA issues, communicates its views and strives to resolve pressing matters.

1. ACER’s Decision on the previous ERAA - February 2023
The ACER Decision on ERAA 2022 identified priority areas where significant improvements were needed:
- internal consistency of the ERAA model (between its investment module and its risk module), and
- external consistency with EU policy objectives (e.g., Fit-for-55 targets), ENTSO-E’s EU ten year network development plan (TYNDP) and TSOs’ cross-zonal capacity targets.
2. ENTSO-E webinar on input data – March 2023
During the ETNSO-E webinar on the preliminary input data, ACER
- highlighted the role of stakeholder involvement in ensuring data quality,
- reiterated a need for reliable input data for robust ERAA results.
3. Response to the public consultation on input data – April 2023
ACER’s response to ENTSO-E public consultation
- provided concrete examples of where assumptions and data should be improved,
- advocated for a consistent application of data within the two modules of ERAA and for enhanced consistency with the EU emission reduction targets.
4. ENTSO-E methodology webinars (part I and part II) – June 2023
During these ETNSO-E webinars, ACER
- recalled the importance of consistency in ERAA implementation as outlined in ACER’s decision on ERAA 2022 and provided examples where progress was expected.
5. The draft ERAA-2023 is expected to be published by ENTSO-E in November 2023. ACER will conduct its review of the draft ERRA and will issue its decision in Q1 2024.