Ensuring System Stability in Europe: The Role of Energy Storage in Providing Inertia

Energy Storage Europe's position paper, "Ensuring System Stability in Europe: The Role of Energy Storage in Providing Inertia", focuses on how the EU can implement a cost-effective and technologically neutral approach to procuring inertia. It also outlines how such an approach should be firmly embedded within a harmonised European methodology for assessing and monitoring inertia needs within the same synchronous areas.

The European power system is becoming increasingly vulnerable to system stability challenges. As traditional synchronous machines are progressively being accompanied by inverter-based renewable energy sources (IBRs), such as PV and wind turbines, the overall system inertia is declining significantly. This reduction limits the system’s ability to withstand sudden frequency deviations and voltage disturbances, increasing the risk of instability. Despite these needs, the European Union still lacks a harmonised framework for assessing inertia needs and, consequently, procuring inertia.

The paper calls for EU-wide non-binding procurement guidelines that would support NRAs and TSOs in delivering inertia as a market-based service, procured via technology-neutral tenders with pre-defined product characteristics, delivery obligations and penalties for non-compliance. European Union and national policymakers should adopt a harmonised framework for the assessment of inertia needs, aiming to quantify local needs based on a common methodology.

Energy Storage Europe calls on the European Commission to accelerate the adoption of the amended NC RfG 2.0, so that all relevant synchronous and inverter-based assets can contribute to system stability on a level playing field.

In particular, Energy Storage Europe identifies the following measures as needed to ensure non-discriminatory market-based mechanisms for inertia procurement.