Tertiärregelung

Tertiärregelung, in the context of electricity markets and grid operation, refers to the tertiary regulation used to balance the power system after disturbances and to restore reserved balancing capacity. It is the third layer in the conventional sequence of balancing energy, following primary (frequency containment) and secondary (frequency restoration) regulation.

The primary objective of Tertiärregelung is to correct residual energy imbalances that remain after automatic primary and secondary responses have acted. It helps to re-establish nominal system frequency and to rebuild the available regulating reserve for future disturbances. Tertiary regulation is typically activated when automatic measures cannot fully restore balance or when there is a need to reinstate planned reserve capacities.

Activation and timing vary by market design and contract. Compared with primary and secondary regulation, tertiary regulation is slower and more deliberate. It is generally activated on timescales from minutes to hours after a disturbance and can involve manual instructions to generation units or demand-side resources to increase or decrease output relative to schedules. In many systems, tertiary regulation energy is procured in advance (e.g., day-ahead or intraday markets) and held in reserve until called upon by the transmission system operator.

Market and participants include conventional power plants, pumped-storage hydro, other flexible generation, energy storage, and sometimes demand-side response. Tertiary regulation is coordinated at the national or regional level and, in Europe, can be cross-border, contributing to overall balancing energy markets and grid reliability.

In summary, Tertiärregelung is a slower, long-horizon balancing tool used to restore energy balance and reserve capacity after primary and secondary regulation have addressed immediate frequency deviations.