Non-frequency-related ancillary services

Frequency deviations can occur in the event of imbalances between the electrical energy supplied and that consumed in a given area. These deviations can occur almost immediately and, depending on the cause, at different locations, for example in the event of a system split. With such rapid changes, inertia is required to immediately and effectively cushion rapidly occurring power imbalances until the primary control system stabilises the grid frequency and secondary control restores it to 50 Hz.

At present, the available inertia is mainly determined by the number and size of the available synchronous generators. In the course of the energy transition, however, these capacities will decrease and power generation based on renewables and battery systems will increase. These latter resources will increasingly have to provide the ability to provide inertia electronically in order to meet demand.

In order to support this development and ensure that sufficient plants capable of providing inertia will be available to ensure stable grid operation in the future, TransnetBW will soon initiate market-based procurement of inertia on the basis of Section 12(h) of the Energy Industry Act (EnWG).

The Federal Network Agency has initiated a procedure under file number BK6-23-010 to define the specifications and technical requirements for the future market-based procurement of inertia. TransnetBW is actively supporting this process and will implement the appropriate procurement processes once the new framework conditions have been defined by the Federal Network Agency.