The first consultation of the procurement concept was initiated by the BNetzA on September 29, 2023, the second consultation started one year later on September 12, 2024. The final determination of the procurement concept by the BNetzA took place on April 22, 2025.
What is Inertia of local grid stability?
Inertia of local grid stability is an inherent reaction to an active power imbalance in order to prevent a violation, even if only local, of frequency stability limits, which can be critical for grid stability. Inherent reaction means in particular the Inertia from synchronous machines (rotating mass) or grid-forming converters (synthetic rotating mass), which has the aim of limiting frequency gradients. The Inertia reacts instantaneously to short-term changes in the voltage angle, counteracts the active power imbalance and limits the frequency gradient at the origin.
Market design (according to BNetzA definition)
The procurement of Inertia takes place via a fixed price system that remunerates the provision of iInertia. The level of remuneration depends on the availability of the unit in the respective billing period, the procurement region and the product offered. The fixed price is determined on the basis of a methodology drawn up by an independent expert.
The products are differentiated according to direction (positive / negative) and availability (basic / premium), resulting in four different products.
The inertia of local grid stability procurement concept regulates the framework for
- Remuneration requirements
- Product definitions
- Deadlines
- Availability
- Framework conditions for pricing
- Remuneration
- Publication obligations of the procuring TSO