German TSOs launch market-based procurement of Momentanreserve (inertia reserve), host stakeholder workshop

German transmission system operators (ÜNB) have moved to a market-based procurement mechanism for Momentanreserve (instantaneous/inertia reserve), operational since 22 January 2026, and are now inviting market participants and stakeholders to a workshop to discuss updates and current market challenges.

This introduces a new competitively procured ancillary service product for grid inertia in Germany, potentially opening a revenue stream for new technologies (e.g., synchronous condensers, grid-forming inverters, batteries) capable of providing inertia, and signals evolving TSO practice on system stability services as renewable penetration increases synchronous inertia scarcity.

The shift to market-based procurement of Momentanreserve represents a structural innovation in German ancillary services design, moving away from purely mandated/regulated provision toward a competitive mechanism. Because inertia has traditionally been a byproduct of synchronous generation, formalizing it as a procurable market product creates new participation pathways for storage, synchronous condensers and grid-forming inverter-based resources, while also requiring TSOs to define technical qualification, measurement, and settlement rules. The follow-up stakeholder workshop, held roughly eight months after go-live, indicates the mechanism is in an early operational learning phase, with TSOs seeking market feedback on design refinements—typical of a young market needing calibration on participation barriers, product definition, or price formation dynamics before broader market maturation.

German TSO ancillary services procurement framework for Momentanreserve

Stakeholder workshop on market-based procurement of Momentanreserve · 22 Sept 2026

Primary sources