Lorraine Williamson
At 12.33 pm on 28 April 2025, Spain’s electricity system failed. Traffic lights went dark, trains stopped, phone networks struggled, and millions of people were suddenly left without power.
One year later, Spain´s blackout anniversary has brought more reports, more technical explanations, and more political blame. What it has not delivered is a single, universally accepted answer.
A year of reports, but no single culprit
The blackout affected mainland Spain and Portugal, with a small area of southern France also briefly impacted. ENTSO-E, the European network of transmission system operators, later described it as an unprecedented incident and published a final expert report in March 2026. The report identified multiple interacting causes and set out recommendations to strengthen Europe’s power system.
That matters because the public debate has often looked for one clear failure. Was it renewable energy? Was it grid planning? Was it the response of power plants? Was it political decision-making?
The official picture is more complicated. European experts have pointed to a chain of events involving voltage problems, generation disconnections, and system-control weaknesses rather than a single dramatic mistake.
Red Eléctrica says the blackout was “unprecedented”
Red Eléctrica, Spain’s grid operator, has marked the anniversary with its own material, describing the blackout as an unprecedented, unpredictable, and multifactorial episode. It has also released a documentary-style reconstruction from the point of view of its technical teams.
The company has repeatedly argued that it did not cause the blackout and that it complied with the rules before, during, and after the incident. In March, it said the European expert report found no cause attributable to Red Eléctrica that led to the total power failure.
That position has not ended the argument. It has simply moved the dispute into a more technical and political phase.
Fresh CNMC files keep the pressure on
The anniversary has also arrived as Spain’s competition and markets regulator, the CNMC, continues to open proceedings linked to the blackout.
Cadena SER reported this week that the CNMC has opened a new “very serious” disciplinary file against Iberdrola and Iberdrola Generación Nuclear. The case concerns alleged issues around production availability and possible reductions in supply without authorisation. The regulator has also opened other files linked to the wider investigation, including one involving Red Eléctrica.
Crucially, these proceedings do not yet mean the companies have been found responsible for the blackout. They do, however, show that the official investigation is still active one year later.
The political fight has not cooled
The blackout has become part of Spain’s wider argument over energy policy.
Opposition leader Alberto Núñez Feijóo has used the anniversary to renew criticism of the Sánchez government and defend a greater role for nuclear energy. He has argued that the blackout was not simply an unforeseeable accident, but the result of policy choices that made the system less secure.
The government and renewable-energy supporters reject attempts to blame clean energy as a simple cause. European grid operators, meanwhile, are now calling for better voltage-control rules across new power plants as Europe adds more renewable generation. Reuters reported that ENTSO-E is pushing for updated EU rules following the Iberian blackout.
What has changed since the blackout?
The clearest change is that Spain and Europe are now focusing harder on voltage control, coordination, and grid resilience.
The ENTSO-E final report recommends measures to improve the system’s response to instability. It also highlights the need for better oversight, stronger coordination, and improved technical requirements for generation connected to the grid.
In plain terms, Europe’s electricity system is becoming cleaner, more decentralised, and more complex. That does not mean renewables are the problem. It does mean the rules, technology, and backup systems must keep pace.
The question that still matters
For many people in Spain, the anniversary is less about technical language and more about trust.
The country has had reports, commissions, political speeches, and regulatory files. Yet the public is still left with a frustrating question: could it happen again?
The honest answer is that Spain now knows far more than it did a year ago. But until responsibility is clearer, sanctions are resolved, and reforms are fully in place, the blackout will remain more than a memory. It will remain a test of whether Spain’s energy system can explain itself when the lights go out.