ACER Launches EU-Flex Model to Assess Electricity Flexibility Needs Across Europe

November 5, 2026 | Europe

The European Union Agency for the Cooperation of Energy Regulators (ACER) has published the preliminary version of EU-Flex, an open-source electricity market model designed to assess flexibility needs across the European Union.

As renewable energy generation continues to expand and electrification increases electricity demand, greater flexibility will be required to maintain grid stability, integrate variable renewable energy and ensure security of supply.

Under the EU's 2024 Electricity Market Design reform, ACER is responsible for assessing electricity flexibility needs across the EU, identifying potential gaps between available resources and system requirements, and recommending measures to address cross-border challenges.

The EU-Flex model will support this process by simulating the European electricity market and analysing how different flexibility resources can help balance electricity supply and demand. These resources include battery energy storage systems (BESS), demand response and cross-border electricity cooperation.

The preliminary release includes an explanatory paper, the model's source code, test-case input data and supporting methodological documentation. By making the model publicly accessible, ACER aims to improve transparency and encourage industry stakeholders to contribute to its development.

The public consultation runs from November 5 to December 17, 2026. ACER will also host an online webinar on November 17 to introduce the model and demonstrate its practical application.

The first EU-wide electricity flexibility needs assessment is scheduled for July 2027.

The initiative represents an important step towards a more coordinated European approach to electricity flexibility planning, with implications for battery storage deployment, renewable energy integration and cross-border electricity markets.