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 Now available on the market: instantaneous reserve through renewables and storage system

The so-called instantaneous reserve is essential for the stable operation of our electricity grids. Since the end of January, it has been available on the market. But what does this mean? Let’s take a look at the latest developments in system stability.

Instantaneous reserve refers to the automatic and immediate energy discharge or absorption by plants in response to power imbalances. It helps stabilise the frequency of the electricity grid, making it a crucial system service for maintaining a stable electricity supply. With its help, disruptions such as large-scale power outages and their serious consequences can be prevented.

^{Instantaneous reserve market launched in January 2026}

Previously, this system service for the grid was primarily provided by large conventional power plants and transmission system operators’ equipment. However, this need not be the case, as instantaneous reserve can also be supplied by other so-called grid-forming systems, such as renewables and storage systems. To facilitate this, the inverters of battery storage systems or renewable energy plants (which, for example, convert direct current into alternating current in solar plants) can now be developed into grid-forming inverters.

Since 22 January, instantaneous reserve has been available for procurement through the market, making it more cost-efficient. This opens the door for inverter-based systems, such as battery storage or wind and solar plants, to provide instantaneous reserve on the market for the first time. With the additional potential for instantaneous reserve, the resilience of the electricity supply is further strengthened. The Federal Network Agency (BNetzA) has established the key guidelines for the market-based procurement of instantaneous reserve.

^{Foundation for market-based procurement of instantaneous reserve adjusted}

In time for the start of the market-based procurement of momentary reserve at the end of January, Forum Network Technology/Network Operation (FNN) at the VDE (Association for Electrical, Electronic and Information Technologies) published a revision of its guidelines ‘Technical requirements for grid-forming properties including the provision of instantaneous reserve’ (in German only). This document provides the technical foundation for market-based procurement. With this revision, all conditions for grid-forming inverters and market-based procurement of instantaneous reserve are now in place. These are considered key milestones in the System Stability Roadmap of the Federal Ministry for Economic Affairs and Energy  – a strategic framework for the secure and resilient operation of the future electricity supply system, based on renewable energy. Manufacturers, grid operators, plant operators, and research institutions are collaborating within the VDE FNN.