EU Gas Storage Refill 2026: ACER Flags Need for Higher LNG Imports Ahead of Winter
Europe can still refill its gas storage before winter 2026/27. Whether it reaches the higher filling level will depend significantly on LNG availability and the pace of storage injections before November.
ACER highlights this challenge in its reaction to ENTSOG’s Summer Supply Outlook 2026. According to ACER’s analysis, meeting summer demand and bringing storage to 90% of capacity before winter would require EU LNG imports to rise by around 13% compared with 2025 levels. An 80% fill is a different story and remains within reach at last year's import levels. ENTSOG also notes that the EU Gas Storage Regulation allows some flexibility on the filling target. The difference illustrates how the targeted filling level affects the EU’s LNG requirements during the remainder of the injection season.
The starting position was uncomfortable. EU storage stood at 28% of capacity on 1 April 2026, below the level recorded at the start of each of the previous three summer seasons. Based on data updated to 2 July 2026, storage had reached around 49%, a level comparable with 2021. However, injections between 1 April and 30 June were below both the ten-year summer average and the 2025 level, putting the refill timeline at risk. ACER encourages Member States and their competent authorities to monitor refill trajectories closely, actively manage risks under the Gas Storage Regulation and ensure timely injections in the coming months.
What ENTSOG's Summer Supply Outlook 2026 Assesses
The outlook keeps returning to one constraint: LNG now covers around half of EU gas imports. ENTSOG, the European network of gas transmission system operators, publishes the assessment each spring, and the 2026 edition asks whether the EU gas system can cover summer demand, keep exporting to neighbouring countries and still inject enough gas to enter winter 2026/27 in reasonable shape. The modelling runs through several LNG availability scenarios.
The phase-out of imports under eligible short-term Russian LNG and pipeline-gas contracts reduces one source of supply available to the EU market, increasing the importance of LNG and other alternative supplies during the refill season. Why Storage Refilling Is Harder in 2026
Three things weaken the commercial case for injections this summer, and ACER names all of them.
Unfavourable price spreads
Storage works as a trade when winter forwards sit comfortably above summer spot. When that spread is compressed or negative, the market incentive for commercial storage injections weakens, which may slow the pace of refilling.
The REPowerEU phase-out of Russian contracts
Under the REPowerEU Gas Regulation, imports under eligible pre-existing short-term Russian LNG contracts were permitted until 25 April 2026, while imports under eligible short-term pipeline-gas contracts were permitted until 17 June 2026. The phase-out reduces one source of gas supply available to the EU market and increases the importance of LNG and other alternative supplies during the refill season.
Middle East volatility
Instability affecting Middle Eastern supplies contributes to gas-price volatility and uncertainty over global LNG availability. These conditions may make it harder for Europe to secure the LNG required for storage and increase the importance of timely injections. How 2026 Compares
A low starting point is manageable when injections run ahead of schedule. In 2026, they are running behind it, from a 28% base on 1 April, with half of the import mix arriving by ship. That combination is the concern.
ACER's own comparison is with recent history: the 1 April level sat below the start of each of the previous three summer seasons. That is why a routine seasonal outlook is getting this much regulatory attention.
We looked at the structural side of this shift in our analysis of Europe's LNG dependency in 2026; by late June, the inventory risk had reached mainstream coverage, including Bloomberg's reporting on below-normal gas stocks.
What This Means for Market Participants
For industrial gas buyers, the storage-refill trajectory is an important indicator for winter supply conditions and price risk. Continued delays could increase market sensitivity to LNG availability, demand and geopolitical disruptions during Q4 2026 and Q1 2027. Procurement and hedging decisions will depend on each buyer’s exposure, mandate and risk framework.
For traders, ACER’s analysis provides a quantified scenario: LNG imports around 13% above 2025 levels would be required to meet summer demand and reach the 90% storage level. The EU’s ability to attract those volumes will depend on global LNG availability, competition with other importing markets and access to regasification and cross-border infrastructure.
ACER’s recommendation signals that Member States may need to manage emerging refill risks actively and in accordance with the Gas Storage Regulation if trajectories fall behind. Key Terms
ACER – the European Union Agency for the Cooperation of Energy Regulators, which monitors EU gas and electricity markets and assesses ENTSOG's seasonal outlooks.
ENTSOG – the European Network of Transmission System Operators for Gas, publisher of the annual Summer Supply Outlook.
Injection season – the period from roughly April to October when Europe refills gas storage ahead of winter withdrawals.
Winter-summer spread – the difference between winter forward prices and current summer prices; the core economic incentive for storage refilling.
REPowerEU Gas Regulation – the EU regulation providing for the phased prohibition of Russian gas imports. Imports under eligible pre-existing short-term contracts were permitted until 25 April 2026 for LNG and 17 June 2026 for pipeline gas, while separate transitional deadlines apply to eligible long-term contracts.
Frequently Asked Questions
How full is EU gas storage in summer 2026?
EU storage stood at 28% of capacity at the start of the injection season on 1 April 2026, below the start of each of the previous three summer seasons. Based on data updated to 2 July 2026, storage had reached around 49%. Injections between 1 April and 30 June remained below both the 2025 level and the ten-year summer average.
How much more LNG does the EU need to refill storage?
Based on ACER's assessment, meeting summer demand and refilling to 90% before winter would take LNG imports roughly 13% above 2025 levels. Reaching 80% is achievable at 2025 import volumes.
Why are storage injections lagging in 2026?
Compressed winter-summer price spreads have weakened the commercial incentive to store gas. At the same time, the REPowerEU phase-out of short-term Russian LNG and pipeline contracts has reduced one source of supply available to the EU market, while Middle East volatility is creating additional uncertainty over LNG prices and availability.
What share of EU gas imports comes from LNG?
Around half. The refill season, therefore, depends significantly on Europe's ability to attract cargoes in a competitive global market.
What does ACER recommend?
ACER encourages Member States and their competent authorities to monitor storage-filling trajectories closely, foster continued progress, actively manage risks in compliance with the Gas Storage Regulation and ensure timely injections in the coming months.
Disclaimer
This article is prepared by D.TRADING for general informational purposes only and does not constitute legal, financial, investment, accounting, tax, or regulatory advice. The information contained herein is based on publicly available sources and reflects opinion on the regulatory environment as of the publication date. D.TRADING makes no representations or warranties, express or implied, as to the accuracy, completeness, or timeliness of the information provided. This document is not an offer or solicitation to buy or sell any energy products, commodities, or financial instruments.
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