FRR (Frequency Restoration Reserve)
A frequency regulation product that restores grid frequency back to 50 Hz after a disturbance, on a slower timescale than FCR products. Available in automatic (aFRR) and manual (mFRR) variants.
In energy storage
BESS participate primarily in aFRR, where the automatic activation signal updates every few seconds and the asset must ramp to full setpoint within the market-defined activation time (e.g. 30 seconds in continental Europe). Participation requires pre-qualification with the local TSO and typically a minimum bid size, though aggregation of smaller units is permitted in most markets.
Also available in: Svenska