Assessing EU Electricity Flexibility Needs: A First Look At ACER’s Open-Source Model

ACER published the preliminary version of EU-Flex, an open-source electricity market model developed to assess flexibility needs across the EU.

What is it about?

Electricity flexibility is the power system’s ability to respond to changes in supply and demand. As renewable generation grows and electrification expands across sectors, the EU will need greater flexibility to ensure security of supply, integrate new renewables and keep electricity affordable.

Under the EU’s (2024) Electricity Market Design reform, ACER is tasked with estimating flexibility needs across the EU, identifying potential gaps between these needs and available flexibility and recommending actions to address cross-border issues. The first assessment is planned for July 2027.

Why a preliminary release?

By sharing the model ahead of the 2027 assessment, ACER aims to make its analysis more transparent, allowing stakeholders to explore the proposed approach and contribute to the model’s development.

Have your say!

Interested stakeholders have until 17 December 2026 to share their views on the:

• paper and methodology, through ACER’s public consultation.

• preliminary version of the model, via ACER’s GitHub repository.

Want to learn more?

On 17 November 2026, ACER will hold a webinar to present the model and demonstrate how to run it. Register for free.