The European Union Agency for the Cooperation of Energy Regulators (ACER) have received a proposal from all Transmission System Operators (TSOs) for the definition of capacity calculation regions.
On 25 March 2026, ACER received a proposal from the European Network of Transmission System Operators for Electricity (ENTSO-E) to amend the methodology for the regional sizing of reserve capacity. ACER will decide on the amendment by June 2026.
