The weeks follow each other and look alike in France. After a slight thaw at the end of last week, a new heat wave is hitting the country. All this in the latent context of the biggest episode of drought that the country has experienced since the beginning of the century. Fires, disaster scenario for agricultural crops, numerous disputes around aquatic resources… In this summer of 2022, France, and Europe as a whole, are taking the brunt of a summary of what will undoubtedly be the norm tomorrow with global warming.
Less visible than forest fires, this wave of heatwave-drought also shakes up the European electricity system. Since the beginning of summer, a period which is normally characterized by a lull in the wholesale electricity markets due to the drop in demand compared to winter, electrons have continued to be exchanged at record prices. On Monday evening, the megawatt hour of French electricity delivered in 2023 was trading at a stratospheric level of 543 euros, according to data from the Epex Sport Stock Exchange compiled by Bloomberg. That is five times more than the average seasonal price of the last five years. Germany is not to be outdone, with prices reaching up to 414 euros per MWh. By way of comparison, the maximum prices in 2021 were respectively 100 euros/MWh for France and 150 euros/MWh for Germany, standards that were already quite high for the time.
How can such a discrepancy be explained? The European electricity system has been confronted for several months now with the surge in Russian gas and coal, fuels for many power stations on the Old Continent. The chronic unavailability of the French nuclear fleet and therefore of France’s export capacities are also fueling this outbreak. The heat wave and the drought do not help these difficulties, affecting all the means of electricity production, contrary to what one might think in France where the debate is systematically polarized around nuclear power.
Hydraulic production is obviously the most affected by the drought. In a study published in mid-July, the Joint Research Center (JRC), the scientific and technical research laboratory of the European Union, calculated that the production of electricity from run-of-river power stations ( which depends on the flow of the river) was below the 2015-2021 average for many countries such as Italy, Portugal and even France. “The same decline is seen for hydroelectric reservoir levels, affecting countries like Norway, Spain, Romania, Montenegro and Bulgaria, among others,” the JRC explains.
The situation is particularly delicate in Norway, which depends 90% on hydroelectric works for its national production. The hydroelectric reservoirs in the area most affected by the drought are 49.3% full, compared to an average of 74.9% for the period 2000-2019 at this time. Also, the Nordic country, which usually exports a lot of electrons through Europe or the United Kingdom, is preparing to temporarily restrict its exports to safeguard its reservoirs in anticipation of winter, according to statements by its energy minister on Monday.
France also feels the blow pass. EDF, which operates a large part of the French fleet, noted in its latest financial report that the country’s water supply (i.e. its monthly flow compared to the interannual average) was particularly low, with a level of filling of the reservoirs at the end of June amounting to “68.4%, close to historical minima”. As a result, EDF is obliged to constantly monitor the flow of waterways and to manage stocks preventively. Its hydraulic production suddenly fell from 33.9 TWh to 25.5 TWh between the first half of 2021 and 2022. The same is true for Compagnie du Rhône, which saw its production drop by 25% over the first seven months of the year.
- Nuclear power, between fantasy and reality
In France, the debate focuses as every summer on the question of power losses on the nuclear fleet linked to the heating of the rivers. While it takes water from certain rivers to cool its power plants (before returning it, almost 100%), the operator EDF is forced by law not to heat the river downstream of its rivers above a certain temperature via its discharges. A constraint which obliges it every summer to modulate the power of certain reactors sporadically, or even to stop some exceptionally, so as not to discharge too hot water likely to have impacts on the local fauna and flora. Since the beginning of the year and until August 5, 0.47 TWh have been lost for this reason, according to calculations by the company Callendar Climate Intelligence, a start-up specializing in the assessment of climate risks. But this figure should swell. On August 6, EDF announced that the new wave of heat wave could force it to make further reductions. Problem, the situation is so tense on the front of the electricity supply this summer that exceptional derogations have been granted for the operator so that it maintains its production and this, even if the temperature of the rivers in question rises to the -above the thresholds allowed under normal operating conditions.
Unacceptable for environmental organizations and some politicians, railing against the impact of this warm-up for fauna and flora. Some, like the boss of rebellious France Jean-Luc Mélenchon or the secretary general of EELV Julien Bayou, also believe that these problems experienced by nuclear power every summer make it “incompatible” with the warming of temperatures, these episodes before s intensify by the end of the century. Naturally, this phenomenon should not be overlooked. But in reality, losses linked to drought-heat waves represent 0.3% of EDF’s annual production, ie a drop of water. The 0.47 TWh of electricity lost due to heat waves since the beginning of the year do not weigh much either in the face of the unavailability of reactors linked to the phenomenon of stress corrosion. Since the start of the year, EDF has lost almost 30 TWh compared to 2021, mainly because of this phenomenon.
That being said, the risk of unavailability for climate-sensitive reactors due to drought or heat wave could “increase by a factor of two to three” by 2050, according to the electricity transmission system operator, TEN. “EDF mentions the figure of 0.3% but it is smoothed over the year. We experienced a summer when up to 6.1 GW of capacity was out of service due to drought and heat, i.e. 10% of the park out of service. As such, it is not enough to be problematic for the network, but when it is combined with other hazards, we can arrive at complicated situations”, explains Thibault Laconde, the founder of Callendar Climate Intelligence.
A situation that calls, according to this expert, for a better understanding of the climate risk for nuclear power. “On the existing fleet, it will be difficult to develop other than marginally. Losses will increase but this should remain manageable. On the other hand, when we build new reactors, it will be necessary to avoid repeating errors, and to design so that they work with the climate of the end of the century, given their lifespan.” A fact to be integrated, but not insoluble as some environmental leaders suggest. Elsewhere in the world, in South Africa, the United Arab Emirates or even in American states, certain nuclear power plants are faced with much more extreme temperatures than in France. EDF ensures, for its part, that it will integrate these climatic hazards in the design of future power plants.
- Coal and gas, also affected
The still divisive nature of nuclear power in France also masks the difficulties caused by the heat and the drought on other energies. The Martigues gas plant had to reduce its production during the second half of July. If EDF evokes external causes linked to the environment, Thibault Laconde sees there again an effect of heat waves. “Whether nuclear, gas or coal, all thermal power plants must be cooled. That of Martigues is usually cooled by the Mediterranean”, he explains to L’Express. However, the warming of the sea since the beginning of the summer has made it impossible for the operator of the power plant, EDF, to operate its turbines at full power without exceeding the regulatory discharge thresholds to which it is also subject.
The drought has other collateral impacts such as in Germany, where the extremely low level of the Rhine, which hinders the movement of freight ships, has effects on the electricity production of our neighbour. The energy company Uniper, which operates several coal-fired power stations in the country, warned at the end of last week that two of these reactors could see their power reduced, for lack of being able to obtain supplies in a normal way.
- Wind and solar power in a communicating vessel
Finally, with regard to the two intermittent renewable means of production, solar and wind, the game of communicating vessel between the two energies plays its full role in this summer period compared to winter. With the summer and the heat wave, production drawn from the wind is obviously very low. This Wednesday at 12 noon, wind power produced only 18% of the production installed in France, against 80% for solar production. It is regularly the opposite during the winter. That being said, the share of solar in the French and European mix (respectively 6% and 5%) does not give it sufficient weight to respond correctly to vigorous electricity demand, particularly given the growing weight of air conditioning. in Europe. High temperatures also affect the performance of photovoltaic panels (production is linked to luminosity), the ideal operating temperature being around 25°C. What fuel a little more soaring prices of which Europe definitely does not see the end.