In March 2026, ACER received a proposal from the European Network of Transmission System Operators for Electricity (ENTSO-E) to amend the methodology for the regional sizing of reserve capacity. After reviewing the proposal and exchanging with stakeholders, ACER has decided to amend the methodology.

What is the methodology about?

The methodology for the regional sizing of reserve capacity (first approved by ACER in 2023) allows regional coordination centres (RCCs) to assess the reserves needed at regional level, taking into account volumes shared between transmission system operators (TSOs) through bilateral agreements. 

This coordination helps reduce procurement costs and ensure a more efficient distribution of reserves across Europe. Based on their assessment, RCCs provide TSOs with recommendations on how to optimise reserve capacity volumes, leveraging the flexibility of the EU electricity system.

What’s new in the amended methodology?

As previously requested by ACER, the methodology now:

• Establishes that all RCCs must rely on data from the previous 12 months when assessing the minimum volume of reserves needed for the following year. This ensures the data used reflects the most relevant and frequent system conditions.
• Specifies, for each system operation region, how much reserve capacity is needed to cover positive and negative imbalances. 
• Introduces a 24-month rolling implementation deadline for assessing the short-term availability of reserve capacity (for sharing agreements established after 1 July 2026).
• Enhances transparency by strengthening and streamlining RCCs’ reporting obligations.

These changes will help RCCs size reserve capacity more efficiently, address TSOs’ operational risks and enhance the process’ transparency and coordination.

What are the next steps? 

As previously agreed, RCCs must implement the methodology’s main changes by 1 July 2026.

As the EU moves towards a decarbonised energy system, the role of gas is evolving. Reducing fossil gas dependence can support the EU’s 2050 climate neutrality target, while also raising important questions around security of supply, affordability and competitiveness.

ACER’s 2026 Monitoring Report on decarbonising the EU's gas market, published today, examines four key dilemmas:

1. Can renewable gases reduce gas import dependency while keeping energy prices affordable?
2. Will natural gas continue to shape electricity prices during the energy transition?
3. Can the EU decarbonise its gas sector without undermining industrial competitiveness?
4. How can methane emissions be tackled, given the potential for low-cost abatement but rising implementation risks?​

What did ACER monitoring find? 

ACER’s monitoring shows that gas decarbonisation can follow two main strategies: Displacing natural gas, by reducing demand or switching to renewables, and reducing its greenhouse gas footprint, for example through carbon capture, storage and measures to address methane leaks.

• Gas demand reductions are not guaranteed. EU gas demand reached 340 bcm in 2025, up 2% from 2024, which could slow progress towards the EU’s decarbonisation goals. Gas continues to provide system flexibility and remains important for industrial competitiveness.
• Gas still affects electricity prices and industry. Gas-fired power plants were economically competitive in 40% of hours in 2025, while low-carbon electricity systems paid on average 40% less than more carbon-intensive peers.
• Biomethane is promising but still limited. Biomethane is the most mature renewable gas option, but with 4.3 bcm of output in 2024, it represents only 2% of gas network injections.
• Methane emissions remain a supply-chain challenge. 85% of methane emissions linked to EU gas and oil consumption occur outside the EU, making implementation of the EU Methane Regulation key but challenging.

Together, these findings show that no single solution can decarbonise the gas sector. A balanced portfolio of technologies and policy measures will be needed, including electrification, biomethane, hydrogen, carbon capture and storage, methane emissions reduction and clean flexibility solutions.

Webinar

ACER will hold a webinar to present the main findings of this report. 

When? 24 September 2026 at 10:00 CET. 

Register for free.

On Thursday 16 July 2026, ACER will open a public consultation on an Annex to the Guideline on REMIT transaction reporting, covering energy derivative transactions.

What is it about?

REMIT is the EU-wide framework that detects and deters market manipulation and abuse in wholesale energy markets. The Regulation was revised in 2024 to keep pace with evolving market dynamics, and its secondary legislation was updated in April 2026 with new and revised obligations.

To reflect these regulatory developments, ACER is updating its guidance, including a new Guideline on REMIT transaction reporting (see ACER’s consultation).

Why are we consulting?

To complement the new Guideline, ACER has developed a dedicated Annex on the reporting of energy derivative transactions. The Annex:

• Clarifies the scope of reporting under REMIT and Regulation (EU) 648/2012 on over-the-counter (OTC) derivatives, central counterparties and trade repositories (‘EMIR’).
• Explains how REMIT reporting exemptions apply for derivatives that are already reported under EMIR.

ACER is seeking stakeholder input to ensure the Annex is clear, practical and supports consistent data reporting across the EU.

Have your say!

The public consultation will run from 16 July to 11 September 2026.

ACER is hoping to hear from any interested parties, including but not limited to market participants, national regulatory authorities, registered reporting mechanisms (RRMs) and organised marketplaces (OMPs).

In this process, ACER will also cooperate and consult with the European Securities and Markets Authority (ESMA).

Read more and get ready to share your views.