Finance

Spain's grid operator blames power plants for blackout, disputes miscalculation

Published by Global Banking & Finance Review

Posted on June 18, 2025

2 min read

· Last updated: January 23, 2026

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Spain's grid operator blames power plants for blackout, disputes miscalculation
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By Pietro Lombardi MADRID (Reuters) -Spanish grid operator Redeia blamed power plants for the massive blackout that affected the Iberian peninsula in April, as it disputed a government report that

Spain's grid operator blames power plants for blackout, disputes miscalculation

By Pietro Lombardi

MADRID (Reuters) -Spanish grid operator Redeia blamed power plants for the massive blackout that affected the Iberian peninsula in April, as it disputed a government report that said its failure to calculate the correct energy mix was a key factor.

REE-owner Redeia's own investigation discovered anomalies in the disconnection of power plants on April 28 even though voltage in the system was within legal limits, operations chief Concha Sanchez told a news briefing on Wednesday.

A combined-cycle plant that was supposed to provide stability to the system disconnected in the first seconds of the blackout when it should not have, while there was also an anomalous growth in demand from the transport network, she said.

"Based on our calculation, there was enough voltage control capabilities planned" by Redeia, she said. "Had conventional power plants done their job in controlling the voltage there would have been no blackout."

Aelec, which represents Spain's main electricity companies including Iberdrola and Endesa, said in a statement on Tuesday it agreed that voltage control was the main cause of the outage, but said that, as system operator, Redeia was ultimately responsible for controlling voltage.

The government's report released on Tuesday said Redeia's miscalculation was one of the factors hindering the grid's ability to cope with a surge in voltage that led to the outage that caused gridlock in cities across the Iberian peninsula and left tens of thousands stranded on trains overnight or stuck in lifts.

But Sanchez said the system was in "absolutely normal conditions" at noon just before the blackout and that adding another gas plant to the system to absorb additional voltage would have made no difference.

Redeia, which is partly state-owned, will release its own full report on the causes of the outage, its chair, Beatriz Corredor, told the same news briefing.

Corredor said she had absolute faith in Redeia's calculations and that the operator had complied with all procedures and rules.

(Reporting by Pietro Lombardi, writing by Inti Landauro and Charlie Devereux, editing by Andrei Khalip and David Evans)

Key Takeaways

  • Redeia blames power plants for the April blackout.
  • Government report cites Redeia's miscalculation.
  • Voltage control was a key issue in the outage.
  • Aelec agrees with Redeia on voltage control responsibility.
  • Redeia to release its own report on the incident.

Frequently Asked Questions

What did Redeia blame for the blackout?
Redeia blamed power plants for the massive blackout that affected the Iberian peninsula, disputing a government report that cited miscalculations.
What anomalies did Redeia find in their investigation?
Redeia's investigation discovered anomalies in the disconnection of power plants during the blackout, despite the voltage being within legal limits.
What was the government's stance on Redeia's calculations?
The government's report indicated that Redeia's miscalculation was a factor that hindered the grid's ability to manage a voltage surge, contributing to the outage.
How did Aelec respond to the blackout?
Aelec, representing major electricity companies, agreed that voltage control was the main cause of the outage but also pointed out that Redeia's miscalculations played a role.
What did Redeia's chair say about their procedures?
Redeia's chair, Beatriz Corredor, expressed confidence in Redeia's calculations and stated that the operator had complied with all procedures and regulations.

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