⚡ Europe’s Green Fragility Exposed.What the EU Doesn’t Want to Talk About:

By Shane Oxer – Energy Commentator

🗞️ Editorial Summary

Spain and Portugal’s 2025 blackout exposed a truth the EU would rather gloss over: a renewables-heavy grid without sufficient inertia is a grid on the edge. As voltage swings return, experts warn that Europe’s rapid green transition has outpaced the physical limits of its power systems — and unless policymakers face the engineering facts, another continental blackout may not be far away.

In late April 2025, the Iberian Peninsula experienced what experts now call the most extensive blackout in Western Europe in more than two decades. Cities went dark, trains halted mid-journey, hospitals switched to emergency generators, and communication networks faltered.

Now, months later, Spain’s national grid operator Redeia (REE) has quietly admitted that the same dangerous pattern — rapid voltage swings — is re-emerging. It’s a warning that cuts straight to the heart of Europe’s energy transition.

⚙️ The Official Line vs. The Engineering Reality

The European Network of Transmission System Operators for Electricity (ENTSO-E) confirmed that the April 28 blackout was caused by excessive voltage.

Official reports are technically correct — but strikingly careful. They emphasise that voltages “remained within margins” while avoiding the deeper issue: why such violent fluctuations occurred in the first place.Behind the bureaucratic language lies a more uncomfortable truth. As renewables occupy a larger share of Europe’s generation mix, traditional sources of grid stability — inertia and frequency response — are disappearing.

🌀 What Is Inertia, and Why It Matters

Inertia in an electricity grid is like shock absorption in a car. It’s provided by heavy rotating machinery — turbines in gas, coal, and nuclear plants — that physically resist sudden changes in frequency or voltage.

Solar and wind farms, by contrast, are linked to the grid through electronic inverters. They inject power, but they don’t spin — meaning they add almost no inertia. When demand shifts or voltage surges, there’s no mechanical buffer. The grid reacts instantly and sometimes violently.

That’s precisely what engineers say happened across Spain and Portugal: a momentary voltage rise cascaded across a system without enough damping power to absorb it.

⚠️ A Fragile Grid Under Stress

REE’s latest bulletin to Spain’s regulator CNMC warns that the grid has experienced new voltage swings in recent weeks — swings so steep they could trigger disconnections of both supply and demand.

Those words are carefully chosen. “Disconnections” is code for automatic shutdowns — the grid’s self-defence mechanism when it senses danger. Too many at once, and the whole system collapses.

While voltages technically remained “within limits,” the speed of the fluctuations was enough to destabilise key nodes in the network. In a conventional grid, turbines would have slowed the rise. In a renewables-dominated grid, the surge simply reflected back and multiplied.

🇵🇹 Portugal’s Week in the Dark

Portugal’s smaller and more isolated grid fared worst. When Spain’s system buckled, the shock travelled west, disconnecting interconnectors and plunging much of the country into darkness.Restoring power took days; in some regions, normal operation didn’t resume for more than a week. Restarting inverter-based systems is slower and more complex than re-energising conventional plants — another unspoken weakness of the green grid.

🔍 The Silence of Brussels

The European Commission’s energy directorate issued only a brief statement praising the “resilience” of Europe’s power networks. There was no direct acknowledgment that a renewables-driven system had shown structural fragility.Across the continent, national governments are doubling down on wind and solar build-outs under the EU’s Net Zero framework. Yet the Iberian blackout stands as an engineering red flag: political ambition has outpaced physical capability.

Grid experts have warned for years that inertia must be replaced, either through synthetic inertia from advanced inverters or rotating stabilisers known as synchronous condensers. These exist — but rollout has been patchy, underfunded, and years behind schedule.

📉 The Hidden Cost of Intermittency

Supporters of renewables point to falling costs per megawatt. But the true system cost includes stabilisation technology, backup generation, and massive energy storage. Without those, the price of instability is borne by the public — in blackouts, lost productivity, and damaged infrastructure.The April event wasn’t a one-off anomaly. It was a glimpse of what happens when a complex, finely balanced system is forced to operate without its mechanical stabilisers.

💬 The Conversation Europe Needs

No one denies that decarbonisation is necessary. The question is how fast and how safely it can be done. Spain’s experience shows that engineering limits don’t bend to political slogans.

Europe’s grid can’t run on ideology alone. Until policymakers acknowledge that stability must come before expansion, the risk of another continental blackout will grow.The warning signs are already flashing — literally.