Reserve products

Reserves are divided into three groups based on their purpose:

1. Frequency Containment Reserves (FCR) are used for the constant control of frequency.
2. The purpose of Frequency Restoration Reserves (FRR) is to return the frequency to its normal range (49.9 - 50.1 Hz) and to release activated Frequency Containment Reserves back into use. 
3. Replacement Reserves (RR) release activated Frequency Restoration Reserves back to a state of readiness in case of new disturbances. (Not used in the Nordic power system)

In addition, Fast Frequency Reserve is used in the Nordics since 2020. It contributes to frequency containment in low inertia situations.

Click to open the picture in a new window, if viewing with a mobile device.