France evolution of Nuclear Generation

Will France have power cuts in the winter of 2022/2023?

In France during the winter of 2022/2023, it is possible electricity supply will not be adequate to satisfy demand and power cuts will be imposed because of many nuclear reactors being out of operation. This page starts with a summary of the situation, followed by the details.

Balance in electricity and generation and consumption

The figures below summarize the actual situation and future predictions for the balance between electricity generation and consumption during the winter of 2022/2023.

The first plot concerns the nuclear power generation, which represents about 70% of the total electricity generation. The plot shows actual generation in 2022/2023 compared to the average generation over the past years of 2016-2021. For the predictions for the future, the generation capacity anticipated from the nuclear reactor restarts announced by the EDF company are used.

Nuclear generation in France in winter 2022/2023. The red curve on the left up to 10 Jan, is the actual nuclear generation, while the dashed red curve to the right, is the nuclear capacity predicated for the rest of the winter on 11 Jan. The black curve is the average nuclear generation over the past 6 years 2015 to 2021. The orange curve is the nuclear generation deficit defined as the difference between the average past generation and the actual 2022/2023 generation or predictions.

The plot shows, for 10 Jan, the scheduled capacity is 45 GW and the actual generation is 42 GW. On 10 Jan, 12 reactors out of 56 are still offline. The EDF schedule has 8 of these reactors restarting in Jan/Feb but plans 9 other reactors to go offline for maintenance in the same period such that at the end of Feb 2023 the scheduled capacity would be 47 GW. The plot shows that the past generation, averaged over 2016-2012, peaked around 53 GW in mid January and then reduced because of reduced demand in warmer weather. The 2023 scheduled capacity becomes similar to the past average in March and the nuclear generation deficit during January and February is be around 5 GW.

To understand if this remaining deficit could lead to power cuts, the generation types other than nuclear and imports/exports must be considered. The next plot summarizes the details of the other generation types which are described in some detail later in this page. The plot compares the actual generation for these other generation types for actual generation in 2022 and the past average over 2016-2022.

Comparison of generation types other than nuclear for actual generation in winter 2022/2023 and the past average of 2016-2022. The black curves are for the sum of wind, solar, hydro, biowaste and fossil fuels and the green curves for wind and solar alone.

The plot shows that the total other generation fluctuates about the past average due to weather variations and is sometimes higher due to increased wind capacity.

These data are combined with the nuclear data and compared to consumption in the following plot. For nuclear the future prediction is the EDF capacity expectation, while for other generation it is taken as the past 6 year average. For consumption the future prediction is also the past 6 year average.

Complete balance between generation and consumption for winter 2022/2023. Total generation is nuclear plus other generation types. The prediction for other generation and consumption are the past average while for nuclear it is the EDF current schedule for capacity.

This plot shows that the prediction for consumption exceeds generation from mid January, a conservative conclusion because no correction is made for the consumption savings discussed below. The deficit between total generation and consumption in the estimate shown in the plot after mid Dec is <4GW.

The last consideration in the balance of electricity supply is the situation of imports/exports and the plot below show the imports in 2022 compared to the past average of imports/exports.

Comparison of import/export in 2022/2023 and the past average of 2016-2021. Imports are values >0 and exports values <0.

The plots shows a peak in imports of 14 GW in early Dec 2022 compared to the past average of around zero at that time. At the end of December the situation became net exports.

The conclusion is that there will be no need for power cuts in France in the winter based on the expectation of the nuclear reactor fleet and normal weather conditions, only unusual extreme weather could cause problems.

Changes in nuclear generation capacity

The generation of electricity in France reached a low point of production of 21 GW at the end of August 2022. The reason for this low point in production was that more than half the nuclear reactor fleet were offline for maintenance.

Generation of electricity from nuclear power in France from 2015 to 2022. Sliding average over 28 days.

Starting at the beginning of September 2022 reactors restarted. On 4 Sept the restart schedule announced by EDF and reported on the website: Nuclear Monitor was recorded. With this schedule 19 reactors were scheduled to restart in September and October and of these 11 actually did in that timeframe. The table below gives the restart dates of those that restarted and the delayed dates (reported on 5 Nov) for those which did not.

Nuclear reactor restart schedule recorded on 5 Nov compared to schedule announced by EDF on 4 Sept

The table below gives the restart schedule as announced by EDF on 4 Nov. Between 4 Nov and 9 Jan, out of the 19 reactors scheduled to restart, 15 had actually done so.

Nuclear reactor restart status recorded on 9 Jan compared to the schedule announced by EDF on 4 Nov

The graph below shows the generation capacity corresponding to the two restart schedules in the tables above, the actual restart capacity and the actual generation. The graph and tables above show large delays in the schedules. The date for the restarted capacity of 35 GW to be achieved was 2 months late compared to schedule announced on 4 Sept. At the end of Dec above average temperatures led to a large reduction in consumption and several reactors were stopped, reducing nuclear generation to 26 GW.

Schedules of nuclear reactor generation capacity according to EDF data on 4 Sept and 4 Nov, together with the actual available schedule capacity of 13 Dec. The actual generation is shown in purple.

The plot below gives the nuclear generation during 2022 compared to the average over 6 years 2016 to 2021. The deficit is the difference between the 6 years average and 2022 generation. The deficit was a maximum of 15 GW in early September and had fallen to 5.5 GW on 13 December. At the end of December many reactors were shut down because of reduced demand due to holidays and warm weather.

Nuclear generation for 2022 compared to average 2016 to 2021, Data for 2022 is plotted averaged over 1 day. "Deficit" is difference.

On 11 Jan 44/56 nuclear reactors were operational, a proportion of 79%. Starting on 20 Jan reactors are planned to turn off for long term maintenance as shown in the table below.

Schedule of reactors maintenance stops starting in Jan-Mar 2023

Changes in consumption

The next plot shows the deficit (difference) in consumption during 2022 compared to the 6 year 2016-2021 average. The reduction in consumption was around 11 GW at the end of Oct but fell during Nov and Dec when the outside temperature conditions returned to the normal situation. On 13 Dec consumption had changed to exceed the past average by 7 GW. These variations in consumption seems to be dominated by temperature variations, as described below.

Electricity consumption in 2022 compared to average of 2016 to 2021. The data for 2022 is averaged over 1 day and the regular fluctuations are due to lower consumption at weekend. "Deficit" is difference between the average 2016 to 2021 and the values for 2022.

Changes in imports/exports

For decades, France has been a net exporter of electricity but in 2022 it changed to become a net importer to compensate for the reduction in nuclear generation. This is shown in the plot below where imports are positive values and exports are negative values.

Evolution of imports/exports in France from 2015 to 2022

The plot below shows the situation of imports/exports in 2022 compared with the 6 year average of 2016-2021. In the past the situation was normally net exports but in 2022 it was nearly always net imports except for a couple of periods like end Oct when there was the large reduction of consumption shown above.

Comparison of impots/exports in 2022 compared to 2016-2021 average.

Compensation of nuclear deficit with consumption and imports

The nuclear generation deficit, reduction in consumption and increase net imports are displayed in the following plot to illustrate the balance. The plot shows that for most of 2022 the nuclear deficit was compensation by imports with a period end Oct/beginning Nov when the consumption reduction was large and imports/exports returned close to the past average values. After mid Nov the temperature in France returned to average seasonal values and electricity consumption rose, such that in this period imports had to increase again to balance the nuclear generation deficit.

Deficit of nuclear generation compared to the compensation from increased imports and the reduction in consumption. When the compensation line is below the nuclear deficit line other generation types are above the past average and when it is above they are below the average.

Changes in other generation technologies

Nuclear generation makes up the largest fraction of the electricity generation mix in France as shown in the pie charts below. Averaged over years, in 2022 nuclear was a fraction 65% of the generation mix down from 71% in 2021 for the reasons discussed above. Fluctuations in the amounts of these other generation types, in particular wind lead to fluctuation in the amount of imports needed to balance demand and contribute to the risk of power cuts.

Contributions to the electricity generation mix in France in 2021 (left) and 2022 (right).

The plot below shows the evolution of the electricity generation mix in France from 2015 to 2022.

Summary of full electricity production with grouping of generation types as indicated. The excess/deficit of generation and consumption is compensated by exports/imports. Until 2022 France normally generated more electricity than was locally consumed and so exported the excess, this changed in 2022.

The plots below compare generation in 2022 with past averages for wind,  solar, hydro and fossil fuel power technologies. Wind and solar show significant increases for 2022 compared to the past average but both have very large fluctuations due to weather. Hydro has significant variations compare to the average but the regular fluctuations are due to the demand reduction at weekends compare to the smoothed past average of the past. Fossil generation is not very different overall during the year 2022 from past averages but has variations related to the fluctuations in wind and solar due to weather.

 Plots of wind, solar, hydro-electricity and fossil, comparing generation in 2022 with past average of 6 years 2016-2021.

The plot below is the sum of wind+solar+hydro+bio+fossil which together make up about 30% of the electricity generation in France.

Plot of sum of all generation technologies beyond nuclear: wind + solar + hydro + biowaste + fossil fuel, comparing generation in 2022 with past average of 6 years 2016-2021.

The plot shows the deficit of the sum of the other generation technologies in 2022 was similar to that of the past average but with fluctuations of around ±5 GW or more due to weather variations.

Temperature dependence of consumption

The electricity consumption in France is very dependent on the ambient temperature because of the widespread use of electricity for heating. The following plot illustrates the variations of average daily consumption, which varies from around 45 GW in summer to above 80 GW in winter.

Comparison of electricity consumption and averages temperature  France. Temperature is averaged over 44 WMO weather stations at locations distributed roughly evenly around France.

The plot below gives the correlation between consumption and temperature for each weekday from 2016 - 2021. The data shows a large increase of consumption in winter, of 3 GW per °C, for heating and a smaller increase in summer for cooling. 

Correlation of consumption with temperature in France, one point per day 2016 to 2021. Temperature averaged over regions of France.

The plot below compares the temperature between Oct and Dec in 2022 with the average 2016-2021. The plot shows variations in the 2022 by +6°C at the end of Oct and -6°C at the beginning of Dec. From the correlation plot about these temperature variations correspond to 18 GW change in electricity consumption.

Temperature Oct-Dec 2022 compared to average 2016-2021. Temperature data is from Wolfram Mathematica database using 44 weather stations around France.

The next plot shows the raw electricity consumption saving and a temperature corrected saving using the data in the previous two plots. It can be seen that while the raw saving is up to 20% at the end of Oct and the end of Dec, the temperature correction changes the saving drastically so the average saving is around zero.

Saving in electricity consumption in France Oct-Dec 2022 compared to average 2016-2021. Dashed curve is the actual (raw) saving and the solid curve is corrected for the temperature variations using a linear adjustment of 3 GW / °C.