With the winter season approaching in Europe, ENTSO-E has published its Winter Outlook for 2025–2026. The purpose of the analysis is to determine when and where the adequacy of the electricity system — i.e., the balance between electricity supply and consumption — may be at risk. The forecast reports are not predictions of the future, but rather outline potential risks to resource adequacy at certain points during the upcoming season. These risks can be proactively addressed through preparatory or mitigating measures. The scenarios identified are based on an assessment of a reference model and various sensitivities, taking into account the possible uncertainties that may arise.

Evolution of generation capacity

Compared to last winter, the installed capacity from renewable energy sources in Europe is about 60 GW higher. Most of this increase is due to the expansion of photovoltaic and wind power in different parts of the continent. Installed solar capacity has grown by 15% and wind energy by 5% in one year. Photovoltaic capacity has increased by around 50 GW across Europe, while wind capacity has grown by 14 GW.

The capacity of battery energy storage systems is also growing rapidly—by more than 150% compared to last winter—but remains relatively small, reaching 28 GW of installed capacity across Europe.

Lignite, coal, and oil power plants see an overall decline in installed capacity of almost 12 GW (-10%). However, in certain exceptional situations, decommissioned capacity may be activated as non-market resources to ensure adequacy or to provide other non-market system services.

On the other hand, more flexible gas-fired power plants see a slight increase, with installed capacity growing by 4 GW compared to last winter. Nuclear energy reports a slight net decrease of 1 GW.

According to ENTSO-E’s Winter Outlook for 2025–2026, all EU countries can cover their peak consumption without the need for imports. However, given the unavailability of conventional generation capacity — such as forced outages or planned maintenance — some areas, such as Belgium, Denmark, Ireland, Finland, and Germany, may need to rely on imports in scenarios with low renewable energy production.

Demand overview

Total electricity demand in the EU is expected to be slightly higher (by 2.9%) than in the previous year, but remains similar to the levels seen in the winter of 2023–2024. The highest weekly consumption is usually observed in January and February. Peak demand in Europe is mainly concentrated during daytime hours.

 Adequacy situation and gas need during winter 2025–2026

Adequacy in the winter of 2025–2026 is assessed by ENTSO-E using a two-step approach. The first step analyses adequacy under normal market conditions. The second stage includes non-market resources, such as strategic reserves, to assess whether they are sufficient to overcome the risks identified in the previous stage. Non-market resources can be activated in the event of a structural shortage of supply on the market.

According to the reference scenario, there is no risk to the adequacy of the system under normal winter conditions in most European countries, including Bulgaria. However, risks exist for Cyprus, Ireland, and Malta due to limited or no connectivity to the European continental network.

Traces of  risks related to capacity shortages have also been identified in Estonia, Finland, Lithuania, Northern Ireland, and Ukraine.

Cyprus may face risks in the event of adverse weather conditions combined with unplanned power outages. As the Cypriot electricity system has no interconnections, the country relies entirely on domestic production.

Ireland faces adequacy risks in the winter of 2025–2026, with peak load expected in March 2026. Although generation capacity has increased over the past year, the system could enter a state of alert during certain periods, particularly when wind farm generation is low and imports via interconnectors are limited.

Certain risks related to capacity shortages have also been identified in Estonia, Finland, Lithuania, Northern Ireland, and Ukraine.

The Maltese system may face risks in early 2026. Based on careful monitoring of adequacy each winter, Malta has put in place specially developed non-market resources that can be activated in the event of a supply shortage.

The systems in Finland, Estonia, Northern Ireland, and Lithuania are exposed to minor risks this winter. Electricity consumers may be affected by a combination of extreme weather conditions or interruptions in interconnections.

In Finland, the electricity system is increasingly dominated by wind power, and the reliability of local electricity generation and interconnections is crucial during cold and windless days.

The situation in the European power system is much more certain for winter 2025–2026 than at the same time three years ago, in the middle of the European energy crisis. As in the previous winter, Europe has much greater assurance regarding fuel supply availability as supply routes have been diversified and alternative supplies identified by many actors. Furthermore, nuclear availability and hydro stocks are in much better shape compared to three years ago.

Прогноза за България

In general, no adequacy issues are expected in Bulgaria for the winter of 2025–2026. For a more complete description of the situation, several important aspects should be noted:

• Peak loads during the coming winter are not expected to be higher than the normal – around 6.5 GW.
• There are no planned outages of thermal and large hydro units scheduled during the examined period of the WO 2025-2026.
• Hydro reserves at the beginning of November 2025 are estimated at 53% which is considered below average, but typically inflows are expected in the months of January and February at the Arda hydro cascade.
• However, a growing concern for the BG power system is its continuous reliance on electricity imports during hours of peak demand and low availability of renewables. This, in combination with unforced outages in the nuclear and thermal generation fleet could create a scarcity situation and put a heavy strain on the system.
• Unfavourable weather conditions, especially heavy snowfall, could create small outages of power supply in the remote mountainous areas as it has happened in the past.
• Good news is the rapid penetration of battery storage systems (1000 MW and increasing) that could relieve the burden on the hydro plants in the peaking hours of the day. Hopefully, one more unit in PSHPP Chaira will be put back in operation at the start of 2026.

More information is avalable in Winter Outlook 2025-2026.