It is necessary to distinguish between the commercial market outcome, ie the balancing of supply and demand, and the physical balance of generation and consumption. When electricity trading leads to a market outcome in which supply and demand on the electricity submarkets are balanced, it does not automatically follow that the physical Electricity generation and consumption is in balance as well. The physical balance may, for example, be different from the commercial market outcome if the actual generation or consumption differs from the forecasts underlying electricity trading due to unpredictable events (such as power plant failures, altered weather conditions or consumption that changes at short notice).

Balancing services correct unpredictable deviations. Transmission system operators procure balancing services to ensure the physical balance between generation and consumption. They calculate the capacity needed for system security. They then acquire this capacity via auctions on the balancing market and are thus able to adjust generation or consumption at short notice. Transmission system operators make a distinction between three types of balancing services: frequency containment reserves (FCR) must be fully available within 30 seconds, frequency restoration reserves with automatic activation (aFRR) within five minutes and frequency restoration reserves with manual activation (mFRR) within 15 minutes. Transmission system operators also distinguish between positive and negative balancing services. Positive balancing services are provided by higher generation or lower consumption, whereas negative balancing services are provided by lower generation or higher consumption.

Comprehensive data on balancing services is shown in the Market data visuals section. Both the capacity price and available amount are given for the FCR. For the aFRR and mFRR, the data are more detailed, with the price for activated balancing services, paid by the transmission system operators per type of reserve, being shown as well. The data are published one hour after the end of the period of use. The amount of exported and imported balancing services is shown as well.

The imbalance data may also be interesting for SMARD users, since, together with the balancing services, the balancing group and imbalance system ensures that at all times just as much power is fed into the electricity grid as is taken from it. Imbalance data is also contained in the Market data visuals section.