What types of balancing services are there?

The Frequency Containment Reserve (FCR) is the fastest balancing services and must be fully delivered within 30 seconds. Providers independently measure the grid frequency at the location of generation or consumption and react immediately to changes in the grid frequency. FCR must be provided symmetrically, meaning there is no distinction between positive and negative FCR (as is the case with aFRR and mFRR). 

The German TSOs procure FCR in a joint tender with other European TSOs (see FCR Cooperation). FCR stops the frequency deviation and stabilizes it, regardless of where in the European interconnected grid the frequency deviation occurred. The amount of energy flowing into the grid area with the balancing discrepancy due to the activation of the FCR is included in the unintentional exchange and is settled monthly between the TSOs. To return the frequency to 50.0 Hertz and replace the FCR, FRR must be deployed in the grid area that caused the frequency deviation.

The automatic Frequency Restoration Reserve (aFRR) balances the system balance of each grid area in the European interconnected grid. 

aFRR consists of two sub-products: positive (power injection) and negative aFRR (power withdrawal). If the system balance is in surplus, meaning more electricity is being produced than consumed, negative aFRR corrects the surplus. If the system balance is in deficit, meaning more electricity is consumed than produced, the deficit is corrected by positive aFRR. 

Compared to FCR, there are some differences. In terms of speed, aFRR forms the bridge between the very fast FCR and the manual mFRR. Additionally, in the balancing services aFRR, a distinction is made between capacity provision (capacity market) and the actual use of balancing energy (energy market). While FCR is activated independently of the source of frequency deviation, each TSO is responsible for keeping its own grid area. 

The TSOs determine the need for aFRR based on the grid area. This is the difference between the planned and actual exports or imports of electricity. Adjusted for the activated FCR, the need is determined, which serves as the input for the load-frequency controller operated by each TSO. This controller distributes the need to aFRR providers, who have a direct connection to the control system of the connecting TSO to exchange data in real-time. aFRR providers must deliver the requested power within maximum five minutes. 

The need and the resulting activation are determined every four seconds ("control cycle"). Additionally, the European TSOs optimize the activation of aFRR via the PICASSO platform.

The manual Frequency Restoration Reserve (mFRR) is used to correct larger system imbalances and is manually deployed to replace aFRR in order to keep it available for the next imbalance situation. mFRR must be fully delivered within 12.5 minutes. 

Like aFRR, mFRR is traded as both positive and negative balancing services. While aFRR tends to be activated continuously, mFRR is rarely needed and usually only for a few 15-minute intervals. Another similarity to aFRR is that mFRR also distinguishes between reserved capacity and delivered energy. 

Despite its name suggesting manual activation, mFRR is not activated via phone or fax, but through the Merit-Order List Server (MOLS). TSOs use this tool to distribute the needs to the providers. Providers access this via a provider-client, receiving all the information they need to fulfill the activation requests. To make the deployment of mFRR as efficient as possible, the European TSOs optimize the use of mFRR via the MARI platform.