Lorraine Williamson
Almost one year after the Iberian Peninsula was hit by an unprecedented power outage, Spain’s blackout investigation has entered a sharper phase.
The Spanish blackout probe has widened, with the CNMC opening further sanction proceedings against energy companies. The move comes just days before the first anniversary of the 28 April 2025 outage, which affected Spain and Portugal and disrupted homes, businesses, transport, and industry.
More energy firms drawn into the investigation
Spain’s competition and energy watchdog has added further companies to its investigation, including Engie Cartagena and TotalEnergies Clientes. Reuters reported that the new proceedings follow earlier probes into Red Eléctrica, Iberdrola, Naturgy, Endesa, and Repsol.
The regulator is examining whether power sector rules were breached over extended periods. It has not been said that any one company caused the blackout.
That distinction matters. The official picture remains complex, with the outage understood as a multi-factor event rather than a single-point failure.
Why this matters now
The timing is significant. With the first anniversary approaching, major companies are also taking steps to protect future legal claims.
El País reported that Repsol, Moeve, and Iryo have begun extrajudicial action to preserve their right to claim damages. The move interrupts the one-year limitation period while the investigation continues.
Repsol has estimated losses of around €125 million, while Moeve put its losses at about €50 million, according to the same report. Insurers are also assessing possible action after paying compensation to affected customers.
Possible fines and long proceedings
The CNMC proceedings could take between nine and 18 months, depending on the seriousness of each alleged breach. The most serious violations may lead to fines of up to €60 million.
That means the blackout’s legal and regulatory aftermath is likely to run well beyond the anniversary.
For households, the question remains simple: how could such a widespread failure happen, and what is being done to stop it from happening again?
Energy companies push back
Some of Spain’s biggest electricity groups have already defended their actions.
Reuters reported earlier this week that Iberdrola and Endesa executives rejected suggestions that their plants caused the blackout. Endesa argued that Red Eléctrica should have done more to maintain system margins, while Red Eléctrica has denied breaching protocols.
That dispute may become central as the investigations progress.
A test for Spain’s energy transition
The blackout investigation also lands at a sensitive moment for Spain’s energy system.
Spain has rapidly expanded renewable generation in recent years. That has brought cheaper clean power, but it has also increased pressure on grid management, storage, and balancing systems.
The investigation is not a verdict on renewables. Yet it does underline the need for a power system that can handle sudden shifts, complex demand, and a growing mix of generation sources.
Accountability could take months
For now, the CNMC’s work is still procedural. Companies will be able to present arguments and evidence before any final decisions are made.
But the probe has clearly moved beyond a technical post-mortem. It is now becoming a fight over responsibility, compensation, and trust in Spain’s power system.
As the anniversary of the blackout approaches, the key question is no longer only what went wrong. It is whether Spain can prove it has learned enough to prevent it from happening again.