ForoNuclear highlights role of nuclear in Spanish energy mix

Friday, 9 May 2025

In the latest edition of its annual report - titled Nuclear Results for 2024 and Future Perspectives - ForoNuclear says Spain's nuclear power reactors generated almost 52.4 TWh net in 2024, slightly down from the 54.4 TWh generated in 2023. As of 31 December, the total installed net capacity of the electricity generation fleet in Spain was 128,987 MWe, of which nuclear accounted for 7117 MWe (net), corresponding to 5.52% of the total installed net capacity.

According to figures from Spain's transmission system operator, Red Eléctrica, renewables - which accounted for 66% of the country's total installed capacity - accounted for 56.8% of Spain's electricity generation in 2024 (wind 23.2%, solar 18.6% and hydro 13.3% and others, including biogas and biomass, 1.7%), up 10.3% compared with 2023.

"The seven operating reactors continued to guarantee supply and energy independence, as they produce baseload power constantly and reliably," said ForoNuclear President Ignacio Araluce. "These aspects are essential in the current geopolitical context, in which Europe is striving to achieve energy sovereignty.

"I would like to highlight that Spanish nuclear power plants are essential in providing strength and stability to the electricity system. For yet another year, they contributed around 20% of the electricity consumed, even though their installed capacity remained unchanged while that of other technologies continues to increase. The plants have operated with the highest quality and safety standards, thanks to the commitment and dedication of the sector's companies, their workers and owners, who invest millions to keep the sites in optimal conditions and prepared for long-term operation."

Blackout response
 

On 28 April, two consecutive generation loss events occurred in southwestern Spain. The remaining generation was insufficient to meet demand, thereby triggering a cascading failure across the entire grid. The fault disrupted electricity supply not only in Spain but also in Portugal, Andorra and parts of the south of France. Red Eléctrica restored most of the electricity supply by early the following day. Investigations into the root cause of the blackout are still ongoing, but a lack of rotating inertia - a term for how resistant a grid is to changes in frequency - is thought to be the likely cause.

Four reactors (Almaraz II, Ascó I and II, and Vandellós II) were operational just before the blackout occurred. Three units were already offline - Trillo was in a scheduled outage, while Almaraz I and Cofrentes were not generating as Red Electrica had requested them not to generate power due to the high contribution from renewable energy in the system.

As a result of the loss of external power supply caused by the blackout, the operating reactors shut down automatically, and safety systems were activated to maintain a safe shutdown, ForoNuclear noted.

"The nuclear power plants acted according to their design and always remained stable and safe," it said. "During the incident, the Nuclear Safety Council activated its Emergency Response Organization [due to the lack of offsite power] and remained continuously informed while monitoring the status of the plants. The reactors are now resuming production after completing all corresponding safety checks, reconnecting to the grid as instructed by the System Operator or when matched in the electricity market."

It added: "It is worth noting that the large turbines and generators in nuclear power plants provide rotating power and inertia to the grid, as they are heavy synchronous machines that help stabilise voltage and frequency."

Phase-out policy
 

There were strong suggestions that renewables were the cause of the blackout, and that there was therefore a need to maintain the nuclear fleet. However, Prime Minister Pedro Sánchez dismissed suggestions that the blackout was the result of his administration's decision to expand the use of renewables while phasing out nuclear power. Under the country's nuclear phase-out plans, agreed in 2019, four reactors are scheduled to close by the end of 2030, while the remaining three reactors will shut by 2035.

"It does not seem logical to cling to a nuclear phase-out plan established 2019 without opening our eyes to reality, especially as the current energy, environmental, and geopolitical context is radically different from what it was then," Araluce said. "The most reasonable course of action would be to revise the closure schedule, considering the crucial role nuclear power plants play in ensuring supply, avoiding CO2 emissions, and helping to contain electricity prices. In fact, recent studies show that without nuclear, electricity in our country would be 23% more expensive for citizens and small businesses, and 35% higher for industrial consumers.

"That said, ensuring the continuity of nuclear energy requires a review of the suffocating tax burden it currently bears. This taxation - which has been increased by more than 70% in the past five years - includes overlapping taxes, regional eco-taxes, and the Enresa fee, which the Government unilaterally raised by 30%. This excessive tax burden, far above the European average, is making Spanish nuclear plants artificially unviable, despite the willingness of their owners to continue operating them and the fact that they are in excellent technical and safety conditions."

Earlier this year, the Plenary Session of the Spanish Congress approved a non-binding proposal calling for the government to implement a series of measures that would reverse the country's decision to phase out nuclear power. The proposal, presented by the right-wing People's Party, was passed on 12 February, with 171 votes in favour, 164 against and 14 abstentions. On 4 April, the Popular Party presented a bill to extend the useful life of nuclear power plants, arguing that it is "necessary" to keep them operational for the long-term.

World Nuclear Association Director General Sama Bilbao y León said: "The economic future of Spain depends on having access to abundant, affordable, 24/365, clean and definitely stable electricity. Thus, maintaining the current nuclear fleet is essential for the economic future of Spain."

Article researched and written by WNN's Warwick Pipe