Winter Outlook 2017/2018 and Summer Review 2017

ENTSO-E analyses possible risks for the security of supply in Europe twice per year: for the summer and winter periods. Because of possible very high/low temperatures and other 'extreme' weather conditions, winters and summers are more the most critical periods for the power grid.

Executive Summary

ENTSO-E’s Winter Outlook 2017/2018 shows that there should not be any risk to security of supply under normal conditions. However, in case of cold spells and low generation availability, ENTSO-E’s analysis suggests that risks can materialise in several countries and mainly during the second week of January.

Under severe conditions, margins are indeed expected to be tight in Great Britain, France, Belgium, Poland and Italy. However, the risk of not having enough generation capacity to cover demand is contained in probability.

Upgraded methodology to cover more critical situations

The ENTSO-E Winter Outlook is a unique pan-European, system-wide, analysis of risks to electricity security of supply. This year’s analysis is more refined than the 2016/2017 edition as lessons from last winter have been taken on board. Last winter, Europe’s power system has indeed faced tensions due to an unforeseen cold spell combined with low availability of nuclear generation in France.

Instead of considering situations that only happen in 1 year out of 10, the Winter Outlook 2017/2018 looks at worst-case situations that could occur in 1 year out of 20. This allows to cover more potential risks. Furthermore, ENTSO-E has analysed risks associated with these extreme climatic conditions taking place simultaneously in all of Europe.

Focus on hydro and impact of gas on power system security

As these also play an important role in electricity security of supply, this Winter Outlook has focused on hydro reservoirs. The hydro reservoir levels in Europe are generally back to historical average, except for Italy and Spain where the levels are close to the historical minimum values.

The Winter Outlook also includes a sensitivity analysis of the impact of potential gas shortage on the electricity security of supply. ENTSO-E and its equivalent for gas, ENTSO-G, have teamed up and their joint assessment shows that the European electricity system stays robust, even in the event of a high demand situation with a simultaneous interruption of gas transit through Ukraine.

In case of over generation (high variable generation and low demand), there may be some curtailment needed in Ireland and in some bidding zones in Southern Italy.

Evolution of generation in Europe

As usual, the Winter Outlook analyses the evolution of the generation fleet, compared to end 2016. The decommissioning of dispatchable thermal power plants has been only partly compensated by new inflexible renewable generation, affecting the power system operation and adequacy for the whole ENTSO-E grid.

In case of unforeseen severe events, ENTSO-E will publish on its Winter Outlook webpage some additional information. ENTSO-E will host together a Winter Outlook webinar on 1 December. All details can be found under our events page.

Evolution of the generation capacity

The analysis of total generating capacities in Europe confirms the decrease of nuclear and thermal and an increase of renewable generation capacities.

Wind & Solar
Mainly thermal

Evolution of net generating capacity in 2017


Special Reports

Managing critical grid situations - Success and Challenges

The report looks at the consequences on systems and markets in the most impacted countries. If the report shows good cooperation notably through Regional Service Coordinators in Western Europe, the cooperation in South East Europe seems to have suffered from a lack of policy and regulatory alignment.

The report lists a series of recommendations like the enhancement of the methodology used in Outlooks to cover more adequacy risks. Today the methodology is not able to forecast situations like the South East Europe January 2017 cold spell. ENTSO-E is committed to make these improvements in time for the next winter outlook.

On net generating capacity, the decrease of fossil fuel (except gas) and the increase in wind and solar is confirmed compared to last summer.

Read Managing critical grid situations - Success and Challenges​​

Annex - A market analysis of the January 2017 cold spell in Europe

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