EDF's largest union is concerned about the stability of the electricity system

The union expressed its "serious concerns" about the future of the electricity network in a letter sent at the end of December to the Minister of the Economy, Roland Lescure, which AFP was able to consult on Friday.

At the heart of its concerns is the perceived excessive use of "modulation", which is increasingly leading EDF to reduce its nuclear production to adapt to electricity consumption when it falls or to compensate for the growing share of renewable energies, which are by nature intermittent depending on the wind and the sun and cannot be controlled, unlike nuclear power.

Given the delay in electrification in the country, "if we make choices with too large a volume of renewable energy (RE), this will have consequences on the modulation of the fleet," André Palu, national secretary of CFE-Energies, in charge of public and European affairs, warned AFP.

It is based on an analysis "conducted independently" by his union and the feedback he received from a report on the subject, written by EDF and which has not yet been made public.

If renewable energy, particularly solar, is developed too rapidly, "it will exacerbate the solar overload," Mr. Palu told AFP. The problem stems from the high solar production during the day in summer, a time when electricity demand is lower, necessitating a reduction in the output of nuclear power plants to balance the grid.

"If there is too much renewable energy production, we will be forced to shut down a number of nuclear power plants (...) the more times a plant is started and stopped, the more the equipment is degraded," with "consequences also for extending the lifespan of reactors," given the "pressure and temperature variations." However, extending the lifespan of reactors is central to France's energy strategy.

"CFE Énergies requests that the study carried out by EDF be submitted to the public debate, published without delay and taken into account in the development of PPE3," the energy roadmap currently being prepared, writes the general secretary of the union, Alexandre Grillat, in his letter to the minister.

"The PPE3 cannot ignore the impact of these demands on the maintenance, availability and lifespan of reactors, nor on the overall economic balance of the nuclear fleet," he insists.

There is a "very strong development today" of photovoltaics, "which poses difficulties on the network", added Gwenaël Plagne, for the CGT Energy (FNME-CGT), who confirms that "the nuclear fleet is modulating more strongly than usual".

But, implicitly criticizing the CFE-CGC's stance, he reiterates his union's wish that the PPE be the subject of a "technical, but above all political debate" in Parliament.

"It is not up to us, despite our positioning, to say before the democratic debate what choice the nation should make for the next 20 years," he concluded.