When an imbalance between generation and consumption occurs on its grid, Elia uses a range of mechanisms to restore the balance.
Each system operator within the ENTSO-E synchronous area is responsible for balancing generation and consumption within its own control area. In Belgium, Elia assumes this responsibility while the access responsible parties (ARPs) are each responsible for maintaining a balance within their own individual balance area.
Elia monitors imbalances on its grid on an ongoing basis. Data pertaining to each quarter-hour period can be accessed via Current system imbalance.
To rectify such imbalances, Elia can exchange imbalances with foreign Transmission system operators via IGCC or Elia can access what are known as contractual reserves (primary, secondary and tertiary reserves): these are volumes of electricity which can be activated upwards or downwards as required. To view a list of available volumes and corresponding activation prices, go to Available balancing energy. For more information concerning the imbalance exchange, go to Ancillary services.
Finally, to cover the costs arising from imbalances among ARPs, Elia applies a tariff to any imbalances identified within their balance area. The amount billed in respect of an imbalance is based on the imbalance prices published for each quarter-hour period. Full details of the imbalance price are available via Imbalance prices. Where an imbalance is identified within an ARP's balance area, that ARP must pay an imbalance bill.
For further information on balancing mechanisms, please consult the relevant product sheets.