The nuclear power plants, in the spotlight for the blackout

BarcelonaKnowing for sure what caused the massive blackout on April 28 last year, which left the entire Iberian Peninsula in darkness for hours, will be difficult. Several investigations have been carried out so far. Red Eléctrica, ENTSO-E (the European group of system operator companies), the National Commission for Markets and Competition (CNMC), the Ministry for Ecological Transition, and others have conducted them. All indicate that there was a combination of circumstances that led to the blackout, but without pointing to anyone in particular.

has already started to open disciplinary proceedingsThe National Commission for Markets and Competition has already begun to open sanctioning proceedings for what happened that day; one, for example, for a possible very serious offense, against Red Eléctrica, the company that operates the system. But it is not the only one. In the last two weeks, the CNMC has opened sanctioning proceedings against various generation plants, both renewable and nuclear, and against electricity distribution companies. And some of the proceedings that have been opened point directly to nuclear plants that, in a situation of maximum renewable production, as was the spring of last year, are called upon to maintain the stability of the system and ensure supply.

In fact, the nuclear lobby has already come out in defense after the proceedings opened against the companies operating some of the nuclear power plants. But of the 56 proceedings that the CNMC has opened so far, only three are for alleged very serious offenses, and, of these, one is for Red Eléctrica and the other two are for nuclear plants: the company that operates Almaraz and Trillo and the one that operates Cofrentes. To these must be added, although for a serious and a not very serious offense, the one opened against the company ANAV, which operates the Catalan nuclear power plants of Ascó and Vandellòs.

The nuclear employers' association distances itself from these proceedings. On the one hand, it assures that they are not for the day of the shutdown. And, on the other hand, they complain that nuclear power plants, in many cases, lose money due to fiscal asphyxia, especially when there is a lot of renewable generation, which inevitably causes the price of electricity to fall in the wholesale market.

"The recent sanctioning proceedings by the National Markets and Competition Commission (CNMC) addressed to various nuclear power plant operators are not related to the shutdown on April 28, 2025, nor do they concern safety issues of the facilities," stated Foro Nuclear in a press release last week, assuring that these proceedings "are circumscribed to different dates and to issues related to compliance with operational procedures (basic provision of voltage control), market offers, and shutdowns motivated by electricity market criteria."

This nuclear lobby emphasized that "nuclear power plants face an economic asphyxia derived from a disproportionate tax burden, which hinders their viability when market prices fall, especially in periods of high renewable penetration. If very low prices are maintained on a sustained basis, the facilities may not even cover taxes and fees, despite having very competitive real operating costs."

To defend themselves against suspicions of disconnection or shutdown of nuclear power plants precisely because of this economic impact when there is a high weight of renewables, Foro Nuclear argued that "plant shutdowns due to the electricity market are always communicated in advance to Red Eléctrica de España, which has the final say." And it added: "All shutdowns have been carried out in accordance with the regulations of the Nuclear Safety Council, following what is established by operating authorizations and being notified in accordance with established procedures."

Maximum pressure

All the fuss about the role of nuclear power during the blackout occurs at a time of maximum pressure to avoid its closure, planned in a schedule agreed between the Spanish government and companies in 2019, which foresees gradually disconnecting the plants until 2035. The government already has the decision on Almaraz on the table. It must decide whether to allow its lifespan to be extended or to begin the process of closing it.

Obviously, the nuclear lobby wants to extend the life of Spanish nuclear power plants. But it is not alone. Last week, the president of the PP, Alberto Núñez Feijóo, strongly defended nuclear energy during a visit to Ascó. It had been a year since the blackout, and Feijóo asked, in statements with the nuclear power plant in the background, to reverse the "ideological boycott" of the Spanish government on nuclear energy. In fact, he promised that if he governs, he will extend the lifespan of the plants throughout Spain "in a coherent, reasonable, and technically sound manner". For the popular leader, this type of energy is fundamental for four main reasons: “To ensure supply, to reduce electricity bills, to generate employment and retain population, and to contribute to decarbonization”. "We have come to Catalonia to commit to its energy autonomy, its industrial future, and to reduce the cost of electricity bills for households,” he said.

Another ally of nuclear power is the employers' association Foment del Treball. Also on the same day as the anniversary of the blackout, a delegation from Foment, led by its president, Josep Sánchez Llibre, went to Brussels to convey to European institutions the need to review the execution of the energy transition so that it is compatible with industrial competitiveness, security of supply, and the objective of climate neutrality. Foment has called for maintaining the electricity supply guarantee provided by nuclear energy. And it assured that it is necessary to avoid the dismantling of Spanish nuclear power plants such as Almaraz, Trillo, Cofrents, Vandellòs, and Ascó.