On 22 May 2024, the National Regulatory Authorities (NRAs) of the Continental Europe Synchronous Area (CE) requested from ACER a six-month extension to decide on the Transmission System Operators’ (TSOs') proposal to introduce a probabilistic dimensioning approach of Frequency Containment Reserves (FCRs).
On 23 July 2024, with its Decision 10/2024, ACER has granted the extension requested by the CE NRAs, who now have until 17 January 2025 to reach an agreement on the TSOs’ proposal.
Why consider probabilistic dimensioning for FCR?
Historically, TSOs in this region have used a ‘deterministic’ criterion for FCR dimensioning, ensuring that the FCR can handle frequency deviations resulting from the worst-case system outages, typically set at 3000 MW.
In November 2023, TSOs proposed a ‘probabilistic’ dimensioning for FCRs, which considers load and generation patterns, as well as inertia factors (such as synthetic and real-time minimum inertia). This approach aims to enhance the power system’s resilience by reducing the probability of insufficient FCR capacity to once every 20 years or less.
