ENTSOG Winter Supply Outlook 2025/2026

Institution: European Network of Transmission System Operators for Gas (ENTSOG)

Date: October 2025

URL: https://www.entsog.eu/security-of-supply (Winter Supply Outlook 2025/26)

File: entsog-winter-supply-outlook-2025-26.pdf

Summary

ENTSOG's annual Winter Supply Outlook 2025/26 (published October 2025, before the February 2026 Hormuz closure) assesses EU readiness for winter 2025–2026 and provides a forward look to summer 2026. The analysis confirms that EU gas infrastructure can meet demand while maintaining >30% underground gas storage (UGS) levels through winter even without Russian pipeline gas, demonstrating EU independence from Russian supply. However, with initial storage at 83% on October 1, 2025 (below the prior year's 94%), the report flags lower starting positions and identifies potential west-to-east bottlenecks under extreme scenarios.

Key Findings

**Initial storage level (October 1, 2025):** EU UGS reached **83% on average** (943 TWh/~86 bcm), compared to **94% in 2024** (1,082 TWh/~98 bcm). National levels ranged from above 90% to as low as 50%. (ENTSOG Winter Supply Outlook 2025/26)

**Reference Winter scenario:** Under normal (Reference) Winter demand, EU gas network meets demand while maintaining more than **30% UGS stock level in all UGS facilities by end of winter** (April 2026). Simulations indicate a potential maximum average storage filling level of **41% across the EU by April 2026**. (ENTSOG Winter Supply Outlook 2025/26)

**Russian pipeline independence demonstrated:** Europe's average UGS stock level could remain above 30% at the end of winter even **without Russian pipeline gas**, demonstrating the resilience and increasing independence of the EU gas system from Russian supply. (ENTSOG Winter Supply Outlook 2025/26)

**LNG dependency:** LNG supply and supply from Norway represent the largest sources of supply for EU Member States. In a **LNG Low scenario** (~1,000 GWh/d cannot be received), demand response or adequate pipeline supply would be needed to prevent storage dropping to 24% by end of winter. Under the LNG Low scenario, storage could drop to **16%** without adequate response. (ENTSOG Winter Supply Outlook 2025/26)

**Cold Winter scenario:** In a Cold Winter with limited LNG supply, Europe would need to activate demand response estimated at **3% of total Cold Winter demand (~92 TWh/~8 bcm)** in the LNG Reference case, and up to **9% (~262 TWh/~24 bcm)** in the LNG Low case. In both cases, only **11% of UGS strategic reserves** would remain by end of winter. (ENTSOG Winter Supply Outlook 2025/26)

**Infrastructure resilience:** The gas infrastructure, including new projects commissioned since the last report, is "boosting energy security in the EU and allows for a more efficient cooperation among the EU Member States." However, under specific circumstances, some possible supply limitations and bottlenecks may occur. (ENTSOG Winter Supply Outlook 2025/26)

**Summer 2026 outlook — Reference scenario:** Starting from 83% on October 1, 2025, EU gas network enables achievement of the **minimum 90% UGS stock level target by end of summer 2026** (September 30). (ENTSOG Winter Supply Outlook 2025/26)

**Summer 2026 — LNG Low scenario:** Under limited LNG supply (LNG Low ~1,000 GWh/d unavailable), the infrastructure alone would be insufficient to reach the 90% target, achieving only **74%** by end of summer 2026. (ENTSOG Winter Supply Outlook 2025/26)

**Peak day and cold spell scenarios:** In high-demand events (2-week cold spell and peak day demand in Reference Winter scenario), **no EU Member State is exposed to demand response**. However, in the Cold Winter + Peak Day + Russian supply disruption scenario, **bottlenecks are observed in South-Eastern European region** — west-to-east cooperation constrained. (ENTSOG Winter Supply Outlook 2025/26)

**Disruption scenarios (Algeria, largest offshore infrastructure):** In Reference Winter demand scenario, additional withdrawal from EU storages would be needed: ~215 TWh (~20 bcm) additional LNG in case of disruption of all Algerian imports; ~111 TWh (~10 bcm) in case of disruption of the largest offshore infrastructure to continental EU. (ENTSOG Winter Supply Outlook 2025/26)

**Storage regulation:** The EU Gas Storage Regulation (EU/2025/1733) requires Member States to achieve **90% filling level between October 1 and December 1**, with flexibility permitted under challenging market conditions. (ENTSOG Winter Supply Outlook 2025/26)

**North-Western region concern:** Storage levels in the North-Western Region remain comparatively low at the onset of winter; further monitoring is recommended. (ENTSOG Winter Supply Outlook 2025/26)

Entities Mentioned

**Organizations:** ENTSOG (European Network of Transmission System Operators for Gas), EU Commission, Agency for the Cooperation of Energy Regulators (ACER), Energy Community
**Places/Countries:** EU Member States broadly; North-Western Region, South-Eastern Europe (SEE), Central and Eastern Europe (CEE); Russia (supply disruptor), Algeria (supply disruptor), Ukraine, Moldova
**Infrastructure:** Underground gas storage (UGS) facilities across EU, LNG terminals, pan-European pipeline network, TurkStream
**Numbers:** 83% (initial storage Oct 1 2025), 94% (initial storage Oct 1 2024), 943 TWh/~86 bcm (83% volume), 30% (minimum end-winter stock target), 41% (max end-April 2026 projection), 90% (EU storage filling target), 1,000 GWh/d (~1 bcm/d equivalent, LNG Low scenario gap), 3% demand response (Cold Winter LNG Ref), 9% demand response (Cold Winter LNG Low), 92 TWh/~8 bcm (Cold Winter LNG Ref demand response volume), 262 TWh/~24 bcm (Cold Winter LNG Low demand response volume), 11% (strategic UGS reserves), 215 TWh/~20 bcm (Algeria disruption LNG need), 111 TWh/~10 bcm (largest offshore disruption LNG need), 74% (summer 2026 LNG Low storage projection)

Relevance to Q1/Q2/Q3

**Q1 (Hormuz closure extent):** Not directly relevant — this report was published in October 2025, before the February 2026 closure. It provides pre-shock baseline data on EU gas storage (83%), LNG dependency, and infrastructure capacity. Useful for before/after comparison.
**Q2 (Price impact):** Low direct relevance — price forecasting is not the primary focus; however, the report documents structural gas supply vulnerabilities (e.g., LNG Low scenarios leading to 74% summer storage) that would amplify price impacts if the Hormuz closure persists
**Q3 (Europe gas/security):** High direct relevance — core institutional source for EU gas security assessment; documents EU's 83% pre-shock storage, LNG as dominant supply source, resilience without Russian gas, and vulnerability to LNG supply disruption

Quotes

"The gas infrastructure, including new projects commissioned, enables demand to be met while maintaining more than 30% UGS stock levels in all storage facilities by the end of the 2025/26 winter season. It also demonstrates independence on Russian pipeline supply in most scenarios where LNG is available in sufficient volumes." — ENTSOG Winter Supply Outlook 2025/26

"The increased role of gas supply in the form of LNG to Europe was also assessed through different scenarios of LNG availability. In addition to the reference scenario, which is based on historical data, sensitivity analyses were conducted for both low and high LNG availability scenarios." — ENTSOG Winter Supply Outlook 2025/26

Q1-SUPPLY-DESTRUCTION Q2-PRICE-IMPACT Q3-EUROPE-IMPACT