Europe – October 31, 2026 -- The EU Agency for the Cooperation of Energy Regulators (ACER) will open a public consultation on 5 November 2026 on the preliminary version of EU-Flex, an open-source electricity market model built to assess flexibility needs across the EU. The consultation will run until 17 December 2026.
ACER must estimate EU flexibility needs under the 2024 market design reform
The 2024 Electricity Market Design reform tasks ACER with estimating flexibility needs across the EU and identifying potential gaps. Flexibility is the power system's ability to respond to changes in supply and demand. ACER plans to publish its first assessment in July 2027, with EU-Flex supporting the process.
Preliminary release includes source code, test case data and methodology
The preliminary release will contain three components:
- An explanatory paper introducing the model and demonstrating its use through a test case.
- The preliminary model, including its source code and test case input data.
- A document describing the underlying methodology.
Stakeholders can examine the modelling approach before the 2027 assessment. ACER wants feedback on the model and its methodology, and aims to identify gaps, limitations and areas for improvement.
ACER schedules 17 November webinar to demonstrate how to run EU-Flex
On 17 November 2026, ACER will hold a free webinar presenting the model, explaining its key features and demonstrating how to run it. Registration is required.