ENTSO-E Adequacy Assessment and Forecasting as a Key Element for European Security Of Supply

ENTSO-E has developed a “Target Methodology for Adequacy Assessment”1) in close cooperation with the Commission, Member States, the Electricity Coordination Group and stakeholders, covering in particular the stochastic aspects of high shares of RES in power systems.

This state-of-the-art methodology should be used on the pan-EU level as the ‘best practice’ methodology, providing common definitions of adequacy indicators and enabling the consistent comparison of adequacy levels across Europe.

The ENTSO-E methodology provides reliable and harmonised indicators for adequacy assessments across Europe and will include flexibility assessments, common definitions of indicators and common methodologies, modelling the role of cross-border exchanges using probabilistic methods. The methodology will therefore provide a realistic hour-by-hour simulation of load variations, forced outages, cross-border flows and fluctuations of external factors such as hydrology, wind, sun, and temperatures based on a European climate database. Based on the hourly simulations, the adequacy methodology will provide in particular a much more detailed view of cross-border contributions to each Member State’s system adequacy, especially in moments of scarcity, as well as information about the needs for flexibility in the respective power systems.

The use of this common ENTSO-E methodology for regional and pan-European adequacy assessments will ensure that common definitions, indicators and consistent adequacy indices’ calculations, based on ENTSO-E’s modelling tools, will provide for the first time a harmonized ground for Member States to discuss their chosen national adequacy indices and security of supply targets, both regionally and across Europe. ENTSO-E hopes that this tool will enable Member States to discuss cross-border support during widespread scarcities and identify and address simultaneous scarcity situations and cross-border effects of energy mix in a much more informed manner.

Depending on the specific type of adequacy risks and needs, the geographic scope of the common adequacy methodology will vary to take into account the specificities of geographical distribution of resources (regional, national, local level) and their links to grid constraints and planning. Some level of details and sensitivities will and should be better accounted for at the national or regional level, especially with regard to decisions about measures to ensure security of supply.

ENTSO-E’s regional and EU-wide adequacy assessments would thus be used to identify adequacy risks and improve the European market design. The regional adequacy assessment would serve as a basis for regional measures to ensure security of supply, e. g., market design adaptations. National adequacy assessments would be used as a basis for local market design adaptations to ensure that energy policy objectives are met. The application of consistent methodologies between the national and the regional levels would allow for accounting realistically for cross-border support being available under the many different scenarios simulated. The methodology should be common and shared between these three levels, taking into account national sensitivities and specificities. However, the decision to implement measures to ensure security of supply at the national level is directly connected to the responsibility for security of supply. Only the entity responsible for security of supply can make the decision to implement or not measures to ensure security of supply. Indeed, this should be done in coordination with neighbouring Member States and TSOs.


  1. ENTSO-E’s system adequacy methodology should become the basis for enhancements of the market design, security of supply and market integration at a regional and European level.

  2. ENTSO-E’s regional and European adequacy methodology should be adapted by and used across Member States to guide their decisions on capacity mechanisms, support schemes, and security of supply on the basis of their national sensitivities and specificities.