Automatic frequency restoration reserve (aFRR)

In 2013, the Nordic TSOs introduced a new type of reserve, Automatic Frequency Restoration Reserve (aFRR), in the Nordic power system. Its purpose is to return the frequency to the nominal value of 50 Hz. aFRR is a centralised automatically activated reserve. It activates based on an activation request signal sent by the TSO. The activation request is calculated based on the frequency deviation in the Nordic synchronous area.

The minimum capacity of regulation is 1 MW and full activation time is 5 minutes maximum. Please see Technical requirements and prequalification process of aFRR for more information.

Fingrid procures aFRR reserve from Nordic capacity market. aFRR is procured for hours during which the frequency tends to vary the most. The procurement hours are informed in advance.

A balance service provider can submit bids to the capacity and energy markets separately for up-regulation and down-regulation. Capacity payment is determined based on the price of most expensive accepted bid (marginal pricing) and it is paid to the balance service provider. Energy fee based on the energy market activations and is paid to the Balance service provider acording to the marginal price of the market period. Regulation energy is corrected for the balance responsible party of the reserve resource.

In addition, a project aiming for a common European aFRR energy market is also on-going.

Procurement of automatic Frequency Restoration Reserve (aFRR)