Strengthened Connections: Keystone of the European Power Grid Network
In the realm of electricity networks, connections between countries are more than just convenient—they're essential for managing the flow of power and maintaining grid stability. This was crystal clear during the unexpected blackout that hit the Iberian Peninsula in April 2025.
Onyema Nduka, senior lecturer in power sustainability at Royal Holloway University of London, explained that while electricity outages are as rare as hen's teeth in European countries, they can occur, as demonstrated by what transpired in Portugal and Spain.
Ideally, the system should be built with redundancies in place, such as multiple supply points, backup generators strategically located, interconnected wires, and cables. Grazia Todeschini, a reader in engineering at King's College London, shed light on the fact that Europe boasts the largest synchronous electrical grids globally, supplying over 400 million customers across 32 countries and most of the EU.
However, this vast interconnectedness can have its pitfalls. In special and extreme scenarios, outages can spread like wildfire, jumping borders and causing mayhem. That's precisely what happened on that fateful Monday when the outage in Spain made its way across the border and hit Portugal.
The Iberian Peninsula being situated at the edge of the European electricity network makes it something of an "electricity peninsula," with Spain and France separated by the Pyrenees. They've had an interconnection capacity of 2.8GW since 2015, aiming to increase it to 5 GW by 2028. Spain is also interconnected with Morocco via a 700MW line, but these connections are nowhere near enough to fully protect the region from such catastrophic events.
The stability of the electrical network is a delicate dance between generating power and meeting demand. Todeschini indicated that measures are in place to limit the impact of outages to small areas, but when the power imbalance becomes too cumbersome, these outages can spread quickly and far.
In this instance, Spain saw a loss of an astonishing 15GW of production in a blink of an eye, causing a widespread blackout. The French high-voltage network operator, RTE, immediately sprang into action, offering assistance to Spain via interconnectors between the two countries. They managed to gradually inject up to 2GW into the Spanish network, dependent on local demand.
To deal with such situations, RTE has protocols in place with numerous manual and automatic "defence barriers" to address all possible scenarios, from stemming the propagation of an incident to restoring power to consumers in the event of a black-out. On this particular day, RTE activated automatic security measures that isolated the Iberian peninsula, stopping the instability from spreading to central Europe.
Rystad Energy, a company specializing in energy research, highlighted that the role France played in the crisis was absolutely critical. The sudden drop in Iberian demand forced France to temporarily reduce its generation output and reroute its energy flows. This included a shut-down of the Golfech nuclear power plant in southwest France around the same time as the outage in Spain and Portugal.
Once some semblance of stability returned to Spain, France resumed limited exports to aid in recovery. Interestingly, the Iberian network was automatically disconnected from the European network between 1038 and 1130 GMT, and it then took several hours to be completely restored, area by area, in Spain and Portugal.
French energy minister Marc Ferracci explained on RTL radio that cooperation and interconnections between France and Germany, as well as partnerships between RTE, were instrumental in enabling and facilitating the swift recovery of electricity consumption in Spain.
Cross-border links in Europe's electrical grid are the backbone of the continent's energy security, but they require careful management to balance local resilience with system-wide vulnerabilities. Ensuring adequate redundancy and interconnection capacity is crucial to avoiding future outrageous episodes like the Iberian blackout.
- The Iberian Peninsula, despite having interconnection capacity with France and other countries, is vulnerable to widespread blackouts and requires considerable interconnection capacity expansion to prevent such catastrophic events.
- During the April 2025 blackout in the Iberian Peninsula, France played a critical role in aiding recovery by offering assistance through interconnectors and temporary reducing its generation output to reroute energy flows.
- The European electrical grid, with its vast interconnectedness, can have pitfalls, as demonstrated by the 2025 Iberian blackout where outages can spread like wildfire, jumping borders and causing mayhem.
- To maintain grid stability, the system should be built with redundancies, such as multiple supply points, backup generators, interconnected wires, and cables, and measures should be in place to address all possible scenarios, as France demonstrated with their manual and automatic "defence barriers".
- Ensuring adequate investment in energy technology, interconnection capacity, and redundancies is essential to balancing local resilience with system-wide vulnerabilities, thereby preventing future extreme blackouts in the European electrical grid.
