Business Context

Fast Frequency Reserve or FFR is an automatic reserve product that is procured to manage situations with low inertia in the power system, and to prevent the frequency of the power system from falling below 49,0 Hz should a power generation unit or HVDC link be lost. Inertia refers to the ability of the power grid to resist changes in frequency. FFR is procured daily from a national hourly market. The need for FFR procurement is determined by the inertia of the hour. FFR was introduced in the Nordic power system in May 2020. In order for a reserve resource to participate in the FFR market, a prequalification test must be passed.

The activation of FFR reserves are based on the grid’s frequency. Once the frequency falls below a threshold, the resource activates automatically. There is no activation signal sent by Fingrid, the activation must be based on a frequency measurement. The required speed for activation depends on the activation frequency.