Keeping the Balance
Elia aims to maintain the balance on the Belgian grid in real time by making use of the market flexibility offered by Balancing Service Providers (BSPs).

Primary control reserve - Frequency containment (FCR/R1)
Providing an immediate initial response to frequency deviations across Europe.
Secondary control reserve - Frequency restoration with automatic activation (aFRR/R2)
Tertiary control reserve - Frequency restoration with manual activation (mFRR/R3)
Balancing Rules
Elia takes action to restore the balance by using balancing services in accordance with the rules for the compensation of quarter-hourly imbalances (entry into force: 1 December 2018), as approved by the regulator (also known the Balancing Rules).
When determining an imbalance within a BRP’s portfolio, Elia appliesimbalance tariffs proportional to the resources used by Elia to manage the imbalance in the control area.
Dimensioning of balancing services
Elia evaluates and determines the volume of balancing services that may be required to keep the balance in the control area, taking into account active power forecasts and the risk of a dimensioning incident (for example, a sudden drop in active power generation following an unplanned outage of a power plant). In line with Article 228 of the Belgian Federal Grid Code, Elia publishes following documents after approval by the regulator:
- the LFC block operational agreement specifying the dimensioning rules for Frequency Restoration Reserves or ‘FRR’ (also referred to as aFRR and mFRR);
- the LFC Means specifying the methodology which determines thevolumes of balancing capacity with which balancing services for aFRR and mFRR will be delivered.