On 19 June 2026, the European Union Agency for the Cooperation of Energy Regulators (ACER) adopted Decision No 07/2026, amending its earlier Decision No 02/2019 on the day-ahead and intraday common capacity calculation methodologies (CCMs) for the Core capacity calculation region (CCR). The amendment removes specific requirements in Article 5(8)(b) and (c) and Article 5(9) of the CCMs, following a General Court judgment that found those provisions incompatible with EU electricity regulations.
The decision responds to a legal process that began with ACER's original Decision No 02/2019 of 21 February 2019, which set out the regional CCMs for the Core CCR covering Belgium, the Czech Republic, Germany, France, Croatia, Luxembourg, Hungary, the Netherlands, Austria, Poland, Romania, Slovenia, and Slovakia. That decision was challenged by German regulator Bundesnetzagentur, leading to a Board of Appeal decision on 11 July 2019 that dismissed the appeal. However, on 7 September 2022, the General Court annulled the Board of Appeal's decision in case T-631/19, BNetzA v ACER. The Board of Appeal then re-examined the case and issued Decision A-003-2019_R on 7 July 2023, confirming the original ACER decision. Further annulment actions by Bundesnetzagentur and Germany led to the General Court's judgment of 1 October 2025 in joined cases T-600/23 and T-612/23, which annulled the Board of Appeal's decision insofar as it adopted Article 5(8)(b) and (c) and Article 5(9) of the CCMs. The court found that those provisions were not permitted under Articles 14 to 16 of Regulation (EU) 2019/943 and Article 29(3)(b) of Regulation (EU) 2015/1222.
On 13 March 2026, the Board of Appeal issued Decision A-003-2019_R_R, remitting the case to ACER and instructing the agency to remove the contested requirements. ACER's new Decision No 07/2026 implements that instruction by deleting the specified provisions from the day-ahead and intraday CCMs for the Core CCR. The amendment ensures compliance with the General Court's ruling and the Board of Appeal's subsequent direction.
The decision impacts transmission system operators (TSOs) in the Core CCR, who must now apply the amended CCMs without the removed requirements, which previously imposed additional constraints on capacity calculation. National regulatory authorities in the region will oversee the implementation. The change may affect cross-border electricity trading efficiency, as the removed provisions were designed to manage congestion but were found to exceed legal authority. Stakeholders, including electricity traders and consumers, may experience altered capacity allocation outcomes, though the net effect on market integration remains to be seen.