ACER to decide on amendments to the Core region’s long-term capacity calculation methodology
ACER to decide on amendments to the Core region’s long-term capacity calculation methodology
What is it about?
ACER will consult on amendments to the long-term capacity calculation methodology of the Core capacity calculation region (CCR) from 27 February until 27 March 2026.
On 21 November 2025, the Core CCR’s transmission system operators (TSOs) submitted a proposal to their national regulatory authorities (NRAs) to amend the long-term capacity calculation methodology. As the NRAs could not reach an agreement, the proposal was referred to ACER on 4 February 2026 under the Forward Capacity Allocation Regulation.
The Core CCR comprises 13 countries: Austria, Belgium, Czech Republic, Croatia, France, Germany, Hungary, Luxembourg, the Netherlands, Poland, Romania, Slovakia and Slovenia.
What is the methodology about?
Long‐term cross-border capacity calculation promotes efficient long‐term cross‐zonal trade. By providing reliable capacities to market participants early, it enables long-term planning and hedging opportunities.
The Core CCR’s long-term methodology covers both yearly and monthly processes, using the flow-based approach.
Why change it?
In their proposal, TSOs recommend to:
- Introduce a benchmark process for available transfer capacity, adjusting the flow-based capacity calculation to better reflect historical cross-border transmission capacities.
- Integrate the Ireland and Northern Ireland single electricity market - France bidding zone border into the Core CCR’s long-term capacity calculation process, once the Celtic interconnector is commissioned.
The proposed changes aim to improve long-term capacity calculation in the Core CCR by enabling the implementation of the flow-based methodology. As a transitional measure, the benchmark for available transfer capacity would be applied at the end of the process. This would allow the yearly auction at the end of 2026 (for delivery in 2027), as well as the monthly auctions in 2027, to take place.
The inclusion of the Ireland and Northern Ireland single electricity market – France bidding zone border reflects its recent integration into the Core CCR.
What are the next steps?
ACER aims to reach a decision by 4 August 2026. The Core TSOs shall implement the long-term capacity calculation methodology by the end of 2026.