Workshop: ACER’s new cost efficiency comparison of EU gas TSOs
What is it about?
ACER has been tasked with carrying out a periodic cost comparison assessing the efficiency of gas transmission system operators (TSOs) across the EU. The results should be taken into account by national regulatory authorities (NRAs) when setting the allowed or target revenues of the TSOs.
On 9 and 10 July 2025, ACER will hold a two-day workshop in Brussels to present the draft methodology for its efficiency comparison.
The workshop complements a public consultation on the same topic (running from 17 June to 17 July) and provides an opportunity for stakeholders to ask questions, exchange views and provide feedback.
Event objective
Understanding stakeholders’ views about the efficiency of TSO costs is important in the context of decarbonisation. In the coming years, natural gas is expected to be partially replaced by low-carbon alternatives such as biogas, biomethane and hydrogen.
This transition will affect transmission networks, which might require additional investments to accommodate renewable and low-carbon gases, as well as to ensure continued use of existing infrastructure (i.e. through reinvestments). At the same time, expected lower demand will likely reduce the utilisation of the existing infrastructure, possibly triggering tariff increases (as it has already occurred across Member States). Ensuring cost efficiency is thus key to enable fair, affordable and sustainable energy systems, while supporting EU policy goals outlined in the European Commission’s Action Plan for Affordable Energy.
ACER strongly recommends stakeholders to take part of the event and to provide input on the objectives, design and transparency needs of the efficiency comparison. The event will discuss:
- Objectives and criteria:
- defining the purpose and objectives of the cost efficiency comparison;
- identifying upcoming challenges for natural gas transmission networks;
- assessing the relevance of different factors (such as network utilisation, legacy investments);
- assessing mechanisms to ensure comparability of TSO costs across Member States;
- ensuring transparency and data quality;
- enabling the interpretability of results;
- ensuring legal robustness.
- Method, data and process:
- selecting benchmarking methods;
- requesting data from TSOs;
- defining parameters to support the benchmarking methods;
- outlining the process and timeline for completing the benchmark by 5 August 2027.
What are the next steps?
To gather diverse perspectives, ACER encourages participation from a broad range of stakeholders (such as network users, end-users, consumer associations etc.) to join the discussion on how to achieve a robust efficiency comparison of TSO costs.
Interested in presenting at the workshop? Contact us at AEC@acer.europa.eu.
To actively engage in the discussion, physical attendance in Brussels is required (free of charge). Seats will be allocated on a first-come, first-served basis.
The event will also be streamed (no registration is needed, the streaming link will be published as soon as possible on this page).
A detailed agenda will follow.
Pre-reading material
Workshop documents will be published on 17 June.
Useful background materials: