Fast Frequency Reserve (FFR)

A Reserve Unit participating in the FFR reserve must meet the technical requirements set for the reserve. Compliance with the requirements must be demonstrated through prequalification tests before market participation. The activation of the Reserve Unit is based on a frequency measurement. Therefore, the Reserve Unit must have a controller that regulates power when the unit participates in the maintenance of the reserve. Fingrid does not send an activation signal.

The reserve power must be fully activated within the required time when the frequency falls below a certain value. The BSP can choose any of the activation options presented in the table below.

Activation frequencies and times for FFR:

The minimum duration of activation is 5 seconds if the deactivation rate of the power is at most 20 % of the FFR capacity per second. If the deactivation rate is higher, the minimum duration of activation is 30 seconds. The Reserve Unit must be capable to reactivate within 15 minutes of the previous activation.

The technical requirements and the verification of the regulation capability of the Reserve Unit are described in more detail in the document “The technical requirements and the prequalification process of Fast Frequency Reserve (FFR)” (See Appendix 2 of the FFR market agreement).

The need for FFR procurement depends on the inertia of the power system, so it is only procured for certain hours, and the amount procured generally varies between 0–60 MW. The procurement need is concentrated in the spring, summer, and autumn months during times when the level of inertia is at its lowest. Fingrid publishes a procurement forecast one week, see reserve market information.

Fingrid procures FFR from a national hourly market. On the hourly market, the bids for the hours of the following day are submitted the previous evening. The price of the reserve capacity is determined separately for each hour based on the most expensive accepted bid.

A BSP has the option to submit a combination bid for FFR and FCR-N or FFR and FCR-D Up products. The purpose of the combination bid is to enable flexible bidding for reserve capacity that is suitable for both reserve products. The capacity of the combination bid can be used for the procurement of either reserve product. Reserve capacity participating in the FCR yearly market can also be offered in a combination bid. Submitting a combination bid requires the BSP to have signed both FFR and FCR market agreements, and the Reserve Unit must have passed the prequalification tests for both reserve products.

The FFR market’s requirements for Reserve Units and BSPs, as well as the bidding rules, are detailed in the document “Terms and conditions for providers of Fast Frequency Reserve (FFR)” (See Appendix 1 of the FFR market agreement).