By Martino de Mori

The 2025 Iberian blackout exposed structural weaknesses in Europe’s power systems at a time of rapid electrification. One year on, it highlights the urgent need to adapt grids, rules and control systems to a more complex and decentralised energy landscape.  “These problems are not unsolvable”, experts say. “But Europe must expand and modernise interconnection, transmission and distribution infrastructure”

At 12:33 on 28 April 2025, the lights went out across Spain and Portugal. In a matter of seconds, more than 50 million people lost electricity — one of the largest blackout in Europe in over two decades. All RENFE trains stopped. Madrid’s Barajas airport went dark. Hospitals switched to emergency generators. The event also claimed lives, and for several hours life as modern Europe knows it simply stopped. The outage lasted less than a day, but its implications will last much longer. “One of the things that the Iberian blackout demonstrated“, says Janusz Bialek, Principal Research Fellow at Imperial College London and one of Europe’s leading experts in power system dynamics, “is that life, as we know it, completely stops if there’s no electricity. Things we don’t think about — they just don’t work anymore“. The blackout was not just a technical failure. It was a signal of a power system undergoing a transformation faster than the rules, infrastructure and control systems built to manage it.

That transformation is well underway. The International Energy Agency (IEA) has described the world as moving rapidly into a new Age of Electricity: over the next decade, global electricity consumption is set to grow six times as fast as total energy demand. Since 2010, global installed capacity of solar PV has expanded more than 50-fold, while wind capacity has risen sixfold. The electricity grid is becoming the central nervous system of the modern economy. It is doing so in a geopolitical context that amplifies every vulnerability: war at Europe’s borders, growing risks of physical and cyber attacks on critical infrastructure, and mounting pressure on supply chains for the components that make the transition possible. Into this picture, the Iberian blackout arrives with uncomfortable precision. The immediate trigger was linked to voltage control issues in southern Spain — but both Bialek and Rena Kuwahata, Programme Lead for Grid Modernisation and Electrification at Agora Energiewende, point to a deeper cause. “The real challenge“, Kuwahata argues, “lies in outdated operational and market rules — renewables were not required or configured to help manage voltage levels, and conventional generators were not consistently meeting their system stability obligations either“. The difference, Bialek notes, is not technological, but operational: “The fundamental reason for the blackout was that Spain had not adapted its system operation and control to the high penetration of renewables“.

This points to a challenge that goes well beyond Spain. In the traditional power system, stability was provided automatically — by the physics of large synchronous generators, whose rotating mass gave the grid inertia, frequency support, and resilience. As wind, solar and batteries take their place, that automatic stabilisation disappears. “There is no physics anymore, because everything is programmable,” Bialek explains — meaning that stability is no longer guaranteed by physical inertia, but must be actively designed and controlled. “Those are power electronics devices, and you program them to behave like synchronous machines — but they are not“. The result is a system full of unknowns: hundreds of thousands of different devices, models not fully understood, new instabilities already appearing in several countries. “It took roughly a century to build the frameworks that made traditional power systems reliable”, Bialek notes. “Now, we have to make the same journey in about a decade“.

The investment picture compounds the challenge: investment is still not aligned with what the system actually needs. According to another IEA report, for every dollar spent on renewable power, only 60 cents are spent on grids and storage — a ratio that needs to reach 1:1 if the transition is to remain secure. “You cannot spend all the money on hardware if you don’t know how to run it safely“, Bialek says. Kuwahata frames the same issue in broader terms: Europe must “substantially expand and modernise interconnection, transmission and distribution infrastructure“.

It is precisely this gap — between the hardware of the energy transition and the software needed to manage it — that European projects like INTERSCADA are designed to address. “Traditional SCADA systems, the software platforms that run grid control rooms, were built for a different era”, notes Antonello Monti, Project Coordinator at Fraunhofer FIT and professor at RWTH Aachen University. “They are monolithic, closed architectures, designed for slow electromechanical dynamics and a single type of current”. As hybrid AC/DC networks expand — combining conventional transmission lines with DC links, battery storage and converter-based generation — those systems struggle to adapt. “When you don’t have a modular solution but a monolithic, complex software, upgrading components becomes cumbersome and error-prone, because you cannot easily isolate what needs to be modified“, he explains. The project’s response is a platform that sits alongside legacy systems rather than replacing them — open source, vendor-independent and modular. “The system becomes a co-development“, Monti says, “in which grid operators are deeply involved and can feed in requirements much more flexibly“.

The challenge, as Monti acknowledges, is that this transformation must happen without ever switching the system off. “You do the transformation while the system is alive — and you cannot afford to stop it, not even for one day, while you’re fully revolutionising the way you work“. The same constraint applies to the broader transition. Bialek describes a “chicken-and-egg” dynamic at its core: manufacturers designing inverters need to know what system operators require for stability; system operators need to know what the devices can actually provide. “One side needs to inform the other“, he says. “There needs to be close collaboration — manufacturers and vendors on one side, system operators on the other — to make sure everything works together“. Open cooperation, shared development and systems that remain under European control — this, he argues, is the culture that projects like INTERSCADA are trying to build.

What emerges is a shared diagnosis — and a growing urgency. Kuwahata calls for “better integrated long-term infrastructure planning, faster permitting and interconnection processes”, along with the enabling of flexibility from demand and distributed energy resources. Bialek is no less direct about the scale of the challenge: “System operators are scared — they realise there are questions they don’t have answers to. But these problems are not comparable to putting a man on the moon in 1969. If we put our minds and money into solving them, they can be solved”.

On 28 April 2025, Europe’s power system offered a glimpse of what happens when it fails to keep up. The next test will be whether it can adapt in time.

Cover photo by jony Y (@langdima)