EGC annuls Acer decision on the calculation methodology regarding electricity capacities
Authors: Julia Scheibler und Paula Friederike Linden
On 25 September 2025, the European Court of Justice (‘EGC’) upheld the action brought by both the Federal Network Agency, the national regulatory authority in Germany, and the Federal Republic of Germany, and annulled the decision of the European Union Agency for the Cooperation of Energy Regulators (ACER) on the method for calculating transmission capacities for electricity trading (day-ahead and intraday) in the so-called ‘core region’, which also includes Germany (case T-485/21).
Pursuant to the Regulation 2015/2022 establishing a guideline on capacity allocation and congestion management, ACER adopted on 30th November 2020 a methodology for sharing the costs of redispatching and countertrading in the core region. This core-region includes i.a. Germany, France, Austria and Poland. ACER adopted this decision since the national regulatory authorities of the Member States belonging to the Core Region were unable to agree on a proposal for a capacity calculation method submitted by the transmission system operators. The scope of this methodology extends not only to cross-zonal network elements (interconnectors), but also to all internal network elements with a voltage level higher than or equal to 220 kilovolts (kV).
Arguments of the applicant
The Federal Network Agency argued that internal bottlenecks in the German electricity grid – i.e. internal network elements – have not been sufficiently taken into account by ACER within the cost methodology. In concreto, the Federal Network Agency submitted that ACER should not include internal network elements, which are significantly affected by cross-zonal exchanges, in the capacity calculation dependent on the performance of an economic efficiency analysis and an impact assessment of increasing the threshold for inclusion.
Decision of the EGC
Based on a literal, contextual und teleological interpretation of the relevant regulations, the EGC finds that ACER is not empowered to introduce other requirements than that of being significantly influenced by cross-zonal exchanges in order to determine internal network elements that should be qualified as ‘critical’ and therefore be included in the capacity calculation. The decisive factor must thus solely be whether cross-zonal exchanges have a significant impact on the network element.
Furthermore, the EGC states that the application of the economic efficiency criterion, in so far as it requires transmission system operators to ascertain whether a reconfiguration of their zone or the use of remedial action might not be more economically efficient compared to capacity allocation to address congestion on their internal network elements, is wholly irrelevant, if the minimum capacity of 70% available for cross-zone trade has been reached by those operators. The primary objective of a minimum capacity takes precedence in this respect and must not be affected by additional obligations such as an economic efficiency analysis.
Consequences of the judgement
The judgment of the EGC leads to the annulment of the ACER decision and requires a revision of the method for calculating electricity capacities in the core region without the approaches that have been classified as unlawful. ACER can file an appeal against the ruling with the European Court of Justice within two months.
