Iberian Blackout: ENTSO-E report puts spotlight on grid resilience and voltage control – not on renewables

ENTSO-E's factual report on the "Iberian Blackout" issued on 3 October shows that renewables are not to be blamed for the large-scale outage of 28 April 2025. Instead, the report points to excessive voltage as the probable main cause for the blackout. These findings will be essential for Europe to build more resilient electricity grids and to avoid similar events in the future. In this piece we explain why the Iberian Blackout will also be remembered as a textbook example of dis- and misinformation.

ENTSO-E's expert group has released its preliminary report on the Iberian Blackout. This "factual report" presents key facts and details on the events that led to the blackout which left millions without electricity.

Crucially, it shows that renewables were not to be blamed for the outage. Contrary to initial speculations, the report further says that neither inertia nor inter-area oscillations were root causes.

Instead, the most likely trigger for the blackout was excessive voltage. A sharp increase in voltage led to a cascading loss of generation which affected the whole Iberian system. Fossil, nuclear and renewable power plants alike isolated themselves automatically from the electricity system to protect their electrical equipment from overvoltage. This further increased the voltage peaks until the whole system shut down.

A tale of disinformation

Shortly after the lights went off in Spain and Portugal posts and comments on social media started to pin the blame on renewables. They argued it was not safe to run power systems on high shares of renewables. The ENTSO-E report now dismisses these claims, making the Iberian Blackout a tale of dis- and misinformation.

The claim that even small shares of wind energy increase the risk of blackouts is as old as the technology itself. But it is fundamentally wrong. Reality refutes it every day. In Europe 20% of all electricity consumed comes from wind. Yet we don't see more blackouts. The EU wants to increase this share to more than 50% by 2050.

Denmark already gets almost 60% of its electricity from wind. And Spain 24%. Many European countries, including Portugal, Spain and Greece, have run hours and days solely on renewable electricity. Germany has around 30,000 operating wind turbines. Yet they run one of the most secure and reliable electricity grids worldwide.

Some of the social media commentators might have unknowingly reshared dangerous and misleading facts ("misinformation"). But a closer look at the nature of the comments and the actors behind them suggests that the claims were intentionally spread to mislead the public and stir up opposition to renewables ("disinformation").

Some examples: social media users suspected terror attacks conducted by Russia, Morocco or North Korea, respectively. A fake post of European Commission President Ursula von der Leyen seeming claiming a Russia cyberattack went viral. Euronews felt the need to run a fact check after social media pushed the news that the blackout was an "experiment" conducted by the Spanish Government to evaluate how far they could push the "dependence on renewables". Russian disinformation operations aimed to impersonate media outlets to spread disinformation content. Other fake claims included reports about solar flares and rare atmospheric anomalies.

Research proves how persistent such narratives can be. Fresh polling from Climate Action Against Disinformation (CAAD) lists the different conspiracy theories around the Iberian Blackout and finds that 70% of respondents in Spain still believe at least one of those false narratives - almost half a year after the event.

New online hub to fight dis- and misinformation

Dis- and misinformation are serious issues for Europe's wind industry - not only in the context of the Iberian blackout. False claims fuel opposition to individual projects and have, in extreme cases, led to violent attacks on wind farms.

WindEurope has set up a dedicated online hub to fact-check common disinformation and claims around wind energy.

Grid resilience - what's next?

The European Commission has announced an EU Grids Package. It is expected for November 2025 and will accelerate investments in grid infrastructure. The Iberian blackout serves as a stark reminder of the urgent need for smarter, more resilient electricity grids. Investments in grid stability, voltage control, digitalisation, flexibility and cross-border interconnections are essential to meet Europe's energy security and climate goals.

The EU is also reviewing its energy security framework. The Iberian Blackout will help industry and policymakers better understand grid resilience challenges in modern energy systems. The final ENTSO-E recommendations, expected in Q1 2026, will help further improve the resilience of Europe's power system and avoid similar outages in the future.