ACER publishes its Opinions on requests from seven national regulatory authorities for derogations from applying EU gas network codes and guidelines at interconnection points with third countries. 

These requests have been submitted by the energy regulators of Bulgaria, Estonia, Hungary, Italy, Lithuania, Slovakia and Spain, and are addressed to the European Commission and ACER (in line with the Gas Regulation). 

The Regulation widens the scope of the existing EU gas network codes and guidelines, expanding their application to third countries’ entry and exit points, starting from 5 August 2026. 

If, for specific reasons (e.g. existing long-term contractual arrangements or legal difficulties in establishing a dispute resolution procedure with transmission network operators or natural gas suppliers established in third countries), the EU rules cannot be effectively implemented, national regulatory authorities can request a time-limited derogation.

What is the role of ACER?

ACER’s role is not to issue a recommendation nor to reject or grant a derogation – this is the task of the European Commission.

After receiving the derogation requests, ACER had three months to provide its opinion to the European Commission. To inform its decision-making process, ACER conducted an extensive review of each request, held bilateral discussions with the relevant national regulatory authorities and applied a harmonised approach while considering the specifics of every Opinion.

For the details of each country, see the full text of the individual ACER Opinion. In brief, ACER considers that in Hungary and Bulgaria the relevant network codes have been implemented to the maximum extent possible to date, until certain EU rules are not implemented simultaneously by the neighbouring transmission system operators.

For Estonia, Italy, Lithuania, Slovakia and Spain, ACER has carefully examined the requests and their specific conditions, providing detailed inputs to the European Commission to support the Commission’s decision.

What are the next steps?

The European Commission will decide whether to grant the derogations, taking into consideration the input provided by ACER.

ACER approves the European Resource Adequacy Assessment proposed by the European Network of Transmission System Operators for Electricity (ENTSO-E) for 2025 (ERAA 2025). This draft ERAA was submitted in December 2025 for ACER’s review.

While this marks an important step towards securing Europe’s electricity supply, the ACER approval decision is accompanied by a letter addressed to ENTSO-E. The letter raises concerns about the assessment, in particular persistent methodological gaps and last-minute changes introduced by ENTSO-E shortly before submission, without proper stakeholder consultation. These include a supplementary approach to modelling investment behaviour, which led to a second, less robust set of results that ACER removed to ensure overall robustness.

As the ERAA is increasingly used to justify national measures (such as capacity mechanisms under the EU State aid framework), ACER emphasises the need to safeguard its technical integrity and ensure early, transparent cooperation. 

What does ACER say about the ERAA 2025? 

While the ERAA 2025 provides an important 10-year outlook on resource adequacy, ACER’s analysis identifies several critical areas where further improvements were needed:

• Address model inconsistencies between the investment and adequacy modules, which may otherwise systematically overstate adequacy concerns, leading to unnecessary or costly market interventions.
• Move towards a revenue-based investment module to better reflect whether market revenues can sustain existing capacity and support new investments, particularly in flexible resources (e.g. batteries).
• Reinforce procedural transparency to ensure significant changes are introduced in a timely manner and subject to proper stakeholder consultation. This includes greater transparency on ENTSO-E’s website on what is still a draft ERAA, hence subject to ACER's approval.

Without these improvements, the ERAA risks losing its usefulness as a reference for policy decisions.

What’s next? 

The ERAA 2025 was the last edition before the entry into force of the amended ERAA methodology (March 2026). From the upcoming 2026 edition, ENTSO-E will progressively integrate the amended methodology into future reports. 

ACER will hold a webinar on the updated ERAA methodology on 26 May 2026.

Full implementation of this methodology is needed to support the fast-track approval of capacity mechanisms under the Clean Industrial State-Aid Framework, such as indicating how much firm capacity is needed and calibrating technology-specific derating factors to determine how much each technology can be relied on to deliver when needed. 

Looking ahead, ACER identifies several priorities for ENTSO-E for the ERAA 2026:

• Adopt a revenue-based investment module to improve model coherence and provide a more realistic view of which capacities remain economically viable.
• Work on the full implementation of the amended methodology, introducing the "Trends and Projections" scenario to reflect the observed pace of the energy transition, and deliver capacity mechanism-related parameters to support the fast-track State aid approval process for capacity mechanisms.
• Ensure a more transparent and cooperative development process, including early alignment on methodological changes to ensure timely and efficient delivery of future ERAA annual assessments.
• Strengthen the hurdle rate method used in the assessment to better reflect investors’ risk aversion.

ACER publishes its report on unit investment cost (UIC) indicators for energy infrastructure, updating the reference values last published in 2023. 

What are UIC indicators?

Transparent cost estimation is essential for planning energy networks. Standardised reference values for specific infrastructure costs can improve the quality and credibility of assessments and enable consistent comparisons across the EU.

Under the TEN-E Regulation, ACER is required to develop and publish a set of UIC indicators and corresponding reference values every three years. These indicators provide a common framework for assessing the investment costs of comparable energy infrastructure projects.

What did ACER observe?

The 2026 ACER report provides updated cost information for energy infrastructure, expressed per unit (kilometre, installed power, capacity). It analyses the factors influencing infrastructure costs over time, using cost data and technical information collected from project promoters between October 2025 and January 2026. The report also includes additional indicators and a sensitivity analysis based on an alternative methodology that accounts for cross-country differences in labour costs.

ACER’s analysis shows that: 

• Infrastructure costs have increased above inflation across most categories (e.g. electricity lines, cables and substations). As the indicators are based on historical data from commissioned projects, they do not fully reflect current price levels and may underestimate actual costs.
• Cost drivers point to increased exposure to price volatility and dependence on supply chains, particularly for materials from third countries, as well as other manufacturing-related costs.
• Data representativeness remains limited for several infrastructure categories, with inputs unevenly distributed across countries, which can affect the robustness of the indicators. Future updates would benefit from data covering a wider range of commissioned projects across countries and infrastructure categories.

Despite some limitations, the indicators provide valuable insights into infrastructure costs and support more transparent and informed planning decisions.

Looking ahead

As the assessment is based on historical data from commissioned projects, the indicators may not yet fully reflect recent cost developments. Further work is needed to better capture these cost developments in future updates, for example by exploring alternative methodologies or taking into account recent tender outcomes. ACER notes that regulatory oversight, stronger cooperation on supply chains and better use of existing infrastructure can alleviate bottlenecks.

ACER's latest gas Monitoring Report covers trends in winter 2025-2026. A key is the impact of the evolving Middle East conflict and the closure of the Strait of Hormuz on European gas markets.

This analysis helps inform decision makers on strategies to ensure secure and competitively priced gas in the EU.

What did ACER’s monitoring find?

The EU is vulnerable to energy shocks. To date the 2026 energy crisis is not at the same level of magnitude as the 2022-2023 crisis.

• The Middle East conflict crisis could cut 20% of global LNG exports: EU sourced 7% of its LNG from Qatar during winter 2025/2026, equivalent to 4% of its natural gas imports over the same period. If Qatari production remains offline until December 2026, a global LNG supply shortfall of 26 bcm could arise and EU spot LNG demand could rise to around 56 bcm. Europe’s exposure to further price increases will depend on the duration of the conflict.
• Title Transfer Facility (TTF) gas prices peaked above 60 EUR/MWh after attacks on energy facilities: Price volatility is expected to remain high amid continued uncertainty.
• Competition with Asia for flexible LNG cargoes could push prices up: This could make Europe's summer storage filling more challenging, as heightened competition for flexible LNG cargoes threatens to push prices up further.
• EU underground gas storage ended winter below 30%, due to both higher reliance on gas use for power and a cold winter. EU gas stocks are near a 9-year low.
• Storage targets for the next winter, in accordance with the EU Gas Storage Regulation, may put upward pressure on prices this summer.
• Europe could achieve 80% storage levels at current LNG import rates (~11 bcm/month). Reaching the 90% target would be difficult without additional supply sources. 
• EU gas demand rose slightly year-on-year to around 2400 TWh: This increase was mainly driven by higher gas use in power generation and for heating, due to a colder-than-average winter. 
• Europe’s reliance on US LNG grew amid the phase-out of Russian gas imports. US LNG now accounts for 30% of EU gas imports and about two-thirds of its LNG imports. Russian gas flows continued to decline, falling close to 240 TWh (but still around 14% of total EU gas imports).
• In Europe, gas flows continued to shift away from eastern pipeline supply and to LNG entry points, resulting in higher west–east cross border flows. This shift was also reflected in wholesale market signals, with price spreads in Central Europe widening to over 2 EUR/MWh above the TTF benchmark.

Looking ahead

• Heightened price volatility: European gas prices will remain highly sensitive to global shocks. The Middle East conflict and strong competition with Asian markets for flexible LNG cargoes will be the main drivers of price spikes.
• Costly storage refills: While reaching the 80% storage target ahead of next winter is feasible, lower starting storage stocks and tight global supply mean that filling storage over the summer will likely come at a premium cost and be more vulnerable to sudden market disruptions.
• Geopolitics and supply shifts: Europe's structural pivot away from Russian gas supply will continue. In January 2026, the EU adopted a regulation introducing a gradual and permanent ban on Russian pipeline and LNG imports. This deepens the EU’s reliance on US LNG imports and maintains a west–east and coastal–continental gas pipeline flow in Europe.