Automatically translated with deepl.com.
In September 2023, the Federal Network Agency initiated a determination procedure pursuant to Sections 12h (5) and 29 (1) of the Energy Industry Act (EnWG) on the specifications and technical requirements for the transparent, non-discriminatory, and market-based procurement of the non-frequency-related system service “inertia of local grid stability” (“instantaneous reserve”). On January 22, 2026, the TSOs started the market-based procurement of instantaneous reserve.
The final determination of the procurement concept by the BNetzA took place on April 22, 2025.
Instantaneous reserve is an inherent response to an active power imbalance in order to prevent a violation of frequency maintenance limits, even if only local, which could be critical for grid stability. An inherent response refers in particular to instantaneous reserve from synchronous machines (flywheel mass) or grid-forming converters (synthetic flywheel mass), which aims to limit frequency gradients. The instantaneous reserve reacts immediately to short-term changes in the voltage angle, counteracts the active power imbalance, and limits the frequency gradient at its source.
Instantaneous reserve is procured via a fixed-price system that remunerates the provision of instantaneous reserve. The amount 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 using a methodology developed by an independent expert.
The products are differentiated according to direction (positive/negative) and availability (basic/premium), resulting in four different products.
The “instantaneous reserve” procurement concept regulates the framework for
In accordance with the procurement concept, TSOs are required to publish the following information for a preview period of two years:
The first forecast period 2026/2027 runs from January 22, 2026, to January 21, 2028.
In the first preview period/fixed price period, the procurement regions correspond to the control areas of the German transmission system operators. The reason for this is that there is initially a significant demand for instantaneous reserves in all regions of Germany. In the long term, the transmission system operators plan to adjust the procurement regions depending on residual demand (based on the current system stability report).
The instantaneous reserve requirements until 2030 are taken from the 2025 system stability report and are aggregated by control area in the following figure. The values shown correspond to the instantaneous reserve requirements for the target year 2030, disregarding the most critical 1% of hours.
Once a year (starting in Q1/2027), the transmission system operators will also publish the contracted instantaneous reserve in MW on this page in accordance with the procurement concept, thereby reporting on the status of demand coverage.
In the 2026/2027 preview period, transmission system operators in all procurement regions will procure both basic and premium products in both positive and negative directions.
The currently valid “Framework agreement on the non-frequency-related system service ‘inertia of local grid stability’ (instantaneous reserve) in accordance with Section 12h (1) sentence 1 no. 2, (5) EnWG” can be viewed and downloaded in the Documents and Templates section.
To determine the initial fixed prices valid from January 22, 2026, to January 21, 2028, the four German transmission system operators commissioned an expert opinion to determine the fixed prices, as provided for in the procurement concept in accordance with BK6-23-010.
Based on this, the following fixed prices are set for the first fixed price period:
The following additional information should be noted:
The transmission system operators also provide a non-binding explanatory document, which can be viewed and downloaded in the section “Further information on the procurement procedure.”
The transmission system operators publish information documents and anonymized answers to suppliers' questions of general interest here. If you have any further questions regarding the procurement procedure, please contact the network operators using the contact details below.
Here, suppliers will find the current version of the documents required for submitting bids and during the service provision period.
Previous versions could be linked here in the future.
Here, the TSOs provide information about upcoming information events for stakeholders on market-based procurement of instantaneous reserves. The table below lists the events, information materials, and registration links:
If you have any questions about the market-based procurement of inertia of local grid stability, please contact the responsible TSO: