Winter 2022-2023: significant increase in nuclear availability

No blackout on the French electricity grid for the winter of 2022-2023. In its forecasts for the next cold season, the French electricity transmission network (RTE) envisages a significant increase in the availability of nuclear reactors and the regular operation of gas-fired power stations. However, the operator also calls on the French to adopt eco-gestures through the “Ecowatt” alerts in the tensest moments.

On Wednesday, 14 September, the French electricity transmission system operator (RTE) published its forecast study for the winter of 2022-2023. One of the first remarks of the chairman of the board, Xavier Piechaczyk, is that this exercise has been brought forward to September (as opposed to October-November). This decision is due to the tensions on the electricity network expected to start in autumn 2022. These usually occur in winter, but France and Europe face exceptional energy situations.


This situation is explained on the one hand by “a gas crisis, which appeared in the second half of 2021 with tensions on energy supply and demand following the post-Covid global economic recovery. It has been then amplified by the war led by Russia in Ukraine”. On the other hand, a period of significant maintenance on the French nuclear fleet, linked to the ten-yearly inspections, the planning of which has been postponed to 2020 and 2021 because of the health crisis, has also contributed to aggravating an already tense situation. Then, the discovery of an anomaly in some reactors, called stress corrosion cracking (SCC), led to the shutdown of twelve reactors. Finally, the relatively low hydraulic stocks were linked to significant summer drought.

Less uncertainty about nuclear power

For nuclear energy, the current situation is tense. “The availability of the nuclear fleet was 15 GW below the nominal situation,” explains RTE (out of a fleet of 63.1 GW installed in France). For 2022 EDF anticipates production of between 280 and 300 TWh, i.e., a drop of 25% compared to the 2016-2019 average, calculates RTE. After a low point of around 25 GW this summer, the restoration of the availability of the park will be essential in the supply-demand balance of the following winter. In particular, the re-commissioning of reactors that have been shut down for CCS-related examinations[1]. “Uncertainty about the extent of checks and repairs has decreased over the past few months, which is very positive news for system management,” says RTE.

In concrete terms, RTE has defined three scenarios. The “degraded scenario” is where European exchanges would be limited due to tensions on gas. The “high scenario” targets a high nuclear availability of 50 GW. Finally, the “intermediate scenario,” used as a reference, foresees a regular operation of our gas power plants and increased availability of nuclear power. The regulator expects a nuclear availability of 38 GW on 1 January 2023 and 45 GW on 1 February 2023. In all these cases, RTE excludes any risk of blackout but calls on the French to save energy, particularly during Ecowatt alerts. The use of this system will increase during a freezing winter, as France experienced in 2010-2011.

The forecast for the restarting of reactors presented by RTE is more prudent than the data provided by EDF. The latter aiming at about 50GW in service in the middle of winter. On the same day, Jean-Bernard Lévy, CEO of EDF, was interviewed by the Economic Affairs Committee of the National Assembly. He announced that currently, 30 reactors are available, including 3 in fuel economy for the winter. Of the 26 reactors now shut down, ten are for scheduled maintenance, 10 for repairs following CCS research, 5 for CCS examinations, and 1 for an accidental shutdown. As things stand, EDF expects five reactors to be back in service in September, five in October, seven in November, three in December, and two in January.

Excessive prices

RTE also reported on the increase in electricity prices. These are generally correlated with gas prices and have gradually increased in recent months. But today, these prices are rising sharply, forcing the government to impose a tariff shield. This price hike is not justified, according to RTE.

The experts explain: “Market participants’ concerns about the supply-demand balance for the winter have led to higher forward prices than technical fundamentals reveal. However, the level of risk revealed by RTE’s forecasting analysis does not justify such abnormally high levels without forecasting a downward trend in demand and considering that the availability of the nuclear fleet is lower than the aggregation of the data declared on the transparency registers[2].


At a conference on the energy situation in France on 12 September, Prime Minister Elisabeth Borne also said that “our objective is to stop the explosion of energy prices and bring them back to more moderation.” She spoke of “unreasonable” electricity prices and wanted to “reassure consumers.”

Published on 15 September 2022

By Ludovic Dupin (Sfen)

(Photo by Eric PIERMONT / AFP)

Photo: (from left to right) Thomas Veyrenc, Executive Director in charge of RTE’s Strategy, Prospective and Evaluation division, Xavier Piechaczyk, Chairman of RTE’s Executive Board, Jean-Paul Roubin, RTE’s Executive Director for Customers, Markets and Operations – Copyright: Eric PIERMONT / AFP

[1] In the RTE report, page 16, we read: “the checks (…) were carried out using the techniques available, namely the cutting of portions of piping (…) These processes (…) then require complex repairs, whether or not the reactor is ultimately affected by the defect.

[2] These are EDF’s mandatory publications on the availability of its reactors.