PC_2025_G_04 - Public consultation on the ACER gas TSO cost efficiency comparison draft methodology

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.

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. 

The 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 welcomes stakeholder input on the objectives, design and transparency needs of the efficiency comparison:

• 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.

Privacy statement.

9-10 July: ACER two-day workshop in Brussels to present the draft methodology and discuss stakeholder feedback and views.

Interested in presenting at the workshop? Contact us at AEC@acer.europa.eu.