On 7 July 2026, the national regulatory authorities of the Continental Europe Synchronous Area asked ACER to decide on the minimum activation period that frequency containment reserves providers with limited energy reservoirs must ensure to remain available during the alert state.
Why is the minimum activation period important?
EU’s electric power systems operate at the frequency of 50 Hz. Any imbalance between electricity supply and demand causes the frequency to deviate. If not corrected quickly, this can lead to blackouts.
Frequency containment reserves are the first line of automatic response to such deviations. They are activated within seconds to stabilise the frequency and are provided continuously by power-generating or consuming assets (like batteries, hydro plants, or demand response systems).
Some of these providers, especially batteries or demand-side resources, have limited energy reservoirs and can only respond for a short duration. The System Operation Regulation therefore requires a minimum activation time to ensure these resources remain available during the alert state.
What are the next steps?
ACER intends to decide on the minimum activation period within 6 months.
