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What you need to know about the Iberian Peninsula’s blackout 

29 April 2025
On the morning of 28 April, a major blackout swept across the Iberian Peninsula, cutting power to millions. While the exact cause is still under investigation, this extraordinary event serves as a powerful reminder of the critical importance of Europe’s electricity grid - a system we often take for granted.

What happened? 

On Monday 28 April, between 12:38 and 13:30 CET, Spain’s transmission system was disconnected from the European grid at the 400 kV level due to an issue with a power line connecting French and Spanish Catalonia. The fault triggered a domino disrupting electricity supply not only in Spain but also in Portugal, Andorra, and parts of France.  

Spain’s transmission system operator, Red Eléctrica restored 99% of the electricity supply by early Tuesday morning, but investigations into the root cause of the blackout are still ongoing. 

What’s known so far 

“What we do know is that we had a very serious incident – one that has had major impacts in several European countries at the same time. Something that is very very rare” Eurelectric’s Secretary General Kristian Ruby told BBC.  

While the cause of the blackout is yet to be defined, in there were reports of anomalous oscillations in the high voltage lines before the power shut down. These oscillations caused synchronisation failures between the electrical systems and eventually ended it disturbances across the interconnected European network.  

The impact 

The blackout disrupted key infrastructure across both Spain and Portugal, affecting public transportation, traffic signals, hospitals, manufacturing plants, digital payment systems, as well as nuclear power facilities. 

Banking systems were interrupted, auto traffic control systems went dark, metros were stopped, and intercity trains were halted. Hospitals were particularly affected, with many having to activate on-site generators and reduce services while power was restored. 

Why it matters  

Yesterday’s extraordinary event is a stark reminder that the grid is the backbone of our society. With electricity playing an increasingly important role in our society, we need to   create all the conditions for enable a secure electricity supply.  

“As society relies more and more on electricity, it’s crucial that electricity is reliable”. 

Picture of Kristian Ruby
Kristian Ruby
Eurelectric, Secretary General

Making the grid future-proof 

Investing in a resilient grid is no longer optional. The success of Europe’s energy transitions depends on an extended, fully digitalised grid that can manage the amount of renewables capacity that is set to come. Making the grid fit for the purpose requires an annual investment of €67 billion from now until 2050.  

However, existing technologies can already help reduce these costs. By optimising grid use, annual investment needs could drop to €55 billion – without compromising resilience or performance. 

Conclusion 

Yesterday’s blackout was a wake-up call. It showed that the need to modernise and reinforce Europe’s electricity grid is urgent and unavoidable. Now is the time to invest in the infrastructure that powers everything. 

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