FEATURE: PROACTIVE SECURITY
What caused the outages in Spain and Portugal?
1. The primary technical cause identified was the unexpected shutdown of the France- Spain high-voltage interconnector at 12:33 p. m. CEST. This critical artery linked the Iberian Peninsula to the broader European grid. A series of generation trips in southern Spain( a loss of 2200 MW in generation capacity) shortly before this triggered a rapid cascade. The Iberian grid’ s frequency dropped and voltage increased, leading to its automatic disconnection from France and widespread system collapse.
2. Spain’ s interconnection level with the rest of the EU is relatively low( around 5 % of its capacity), making it more vulnerable to isolated incidents compared to betterconnected regions.
3. While not the direct trigger, experts highlight that the high penetration of variable renewable energy sources( like solar and wind, which constituted around 70 % of Spain’ s generation before the blackout) contributed to the grid’ s fragility. Unlike traditional thermal plants, renewables often lack the“ inertia”( kinetic energy from spinning turbines) needed to stabilise grid frequency during sudden disturbances. The grid lacked sufficient fastresponding flexible resources( like fast-reacting gas turbines, pumped hydro, or battery energy storage systems) to offset the abrupt loss of imported power and maintain stability.
Outage trends in Europe:
RECENT OUTAGES HAVE SHOWN THAT INCREASING DOWNTIME IS NOT ISOLATED TO A SINGLE SECTOR. ACROSS INDUSTRIES, UK ENTERPRISES FACE MOUNTING SCRUTINY OVER DIGITAL RELIABILITY.
Beyond specific blackouts, the European energy sector continues to grapple with increasing general threats:
Heatwaves( June-July 2025): Recent heatwaves across Europe( e. g., in Germany, France, Spain, Poland) have significantly stressed power systems. While not causing widespread blackouts like the Iberian event, they led to:
Increased demand: Daily power demand increased by up to 14 % in Spain and 9 % in France during peak heat.
Thermal plant outages: Heatwaves can force thermal power plants to reduce output or shut down( e. g., due to river water temperature limits for cooling), creating additional stress on the grid. At least 7 GW of offline capacity was marked as“ Forced” during the July 2025 heatwave due to such issues.
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