Spain's energy watchdog seeks to curb voltage swings after 2025 blackout (updated)
19/03/2026 08:11
Report recommends stronger France power links
Watchdog seeks tighter voltage and protection checks
CNMC says blackout occurred despite existing mechanisms
Adds comments from power utilities lobby Aelec in paragraph 10
By Pietro Lombardi
MADRID, March 19 (Reuters) - Spain's energy watchdog has recommended measures to mitigate voltage swings in the country's power grid, as well as boosting French power links, after a blackout last April left large parts of Spain and Portugal without power for up to 10 hours.
The watchdog chief said earlier this week that this latest report would not assign blame. The power failure on April 28 has already led to multiple investigations, including from the government and from the grid operator.
The CNMC report calls for stronger power links with France, for harmonised Spanish and European rules on voltage limits and more rigorous periodic inspections of protection systems, as well as checks on installations after their initial certification.
MECHANISMS WERE ALREADY IN PLACE
Although these measures should help, the report noted that there were already mechanisms in place at the time of the blackout to manage it properly.
A spokesperson for the Energy Ministry said the findings of the report were in line with those of the government's probe.
Some of the measures proposed - such as increasing the supervision over voltage control obligations for players in the power system - have already been included in the rulebook and the ministry is working on others, including the international power links, the ministry spokesperson added.
The report shows the need to keep adapting technical, operational and regulatory frameworks to a power system "in continuous transformation, characterised by a high penetration of renewable generation, a greater operational complexity and an increasing volatility of voltage levels," the watchdog said.
Red Electrica, owned by Redeia REDE.MC, agreed with the CNMC on the need for every player in the system to comply with the rules in force, a spokesperson for the power grid operator said, adding that the company stuck to the rules before, during and after the blackout.
Spanish power utilities lobby Aelec, which represents the country's main electricity companies, including Iberdrola IBE.MC and Endesa ELE.MC, said the report supports its view that power plants were not responsible for the blackout. Operators acted responsibly and in compliance with current regulations, it said.
The CNMC report also made recommendations for sectors affected by the outage, such as railways, gas, fuel and telecommunications.
(Reporting by Pietro Lombardi; Editing by David Latona, Alexandra Hudson, Barbara Lewis and Jane Merriman)
((Pietro.Lombardi@thomsonreuters.com;))