Author: Dr. Nenad Končar, M.Sc.Eng.

Date: May 22, 2025

The massive power outage that paralyzed Spain and Portugal on April 28 was one of the most significant energy disruptions in recent European history. Millions of citizens were left without electricity, transportation collapsed, and communication and financial systems temporarily failed. Although supply was restored within 24 hours, the consequences of that day will echo through European energy institutions for a long time.

What Do We Know About the Cause?

The exact cause of the collapse has not yet been confirmed, although Spanish operator Red Eléctrica and Portuguese REN identified "two significant disconnection events," most likely linked to solar power plants in southwestern Spain. These oscillations triggered a chain reaction in grid frequency disturbances, resulting in automatic protection shutdowns across Iberia, as well as parts of France and Andorra.

Possible causes include extreme weather, grid overload due to high shares of renewables, and — initially — even suspicions of a cyberattack, though this has since been officially dismissed.

System Recovery – A Test of Resilience

Soon after the outage, emergency plans were activated. By 6:30 a.m. the following day, more than 99% of Spain’s electricity demand was restored. However, the technical complexity of restarting power systems — especially in conditions of high renewable integration — highlighted the challenges facing all of Europe.

The Role of Renewables – Culprit or Victim?

Despite speculation, experts agree: renewables were not the cause, but rather revealed both vulnerability and potential. Rapid decentralized production from household PV systems enabled local stability. However, when the system crashed, solar plants lost 15 GW of capacity — clearly indicating the need for better balancing systems, energy storage, and flexible grid solutions.

A Lesson for the EU – and for Croatia

This crisis shows that even interconnected European power systems are not immune to cascading failures. The question arises: do we have enough "inertia", flexibility, and strategic reserves for such scenarios?

Croatia, with its growing share of solar power and increasing decentralization, cannot afford to remain passive. Technologies like battery storage (e.g., container systems with second-life batteries developed by Adriadiesel), active regulation, and smart grids are no longer optional — they are essential.

Conclusion:

The blackout in Spain and Portugal was not just a technical failure — it was a global warning. In an era of climate change and geopolitical tension, energy resilience becomes a new pillar of security.

To ignore this experience would be irresponsible. Europe must accelerate grid modernization, invest in flexibility, and develop solutions to prevent a “mysterious collapse” from turning into lasting chaos.

Contact for cooperation and energy storage solutions:
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