A deep dive into the recent energy crisis in Southern Europe

On April 28, Spain and Portugal experienced one of the most significant power outages in recent European history, affecting around 55 million people and disrupting transportation, communications, and essential services.

In the aftermath, speculation emerged that the blackout was due to the region’s high reliance on renewable energy sources. While this narrative has circulated in some media and political circles, a closer examination reveals a far more nuanced reality, one that highlights infrastructure and grid management challenges rather than failures of renewable energy technology itself.

At the time of the blackout, Spain’s electricity mix was indeed dominated by renewables: solar power provided approximately 59% of the electricity, with wind contributing 12%.

Nuclear and gas accounted for 11% and 5%, respectively. The fault is believed to have occurred in the Extremadura region, home to both extensive solar infrastructure and the Almaraz nuclear power plant. This fault caused an immediate and significant imbalance between electricity supply and demand, which in turn led to a drop in grid frequency and voltage. Protective systems kicked in to prevent infrastructure damage, resulting in cascading disconnections across the Iberian Peninsula.

Critics of renewables have pointed to this high level of intermittent generation as the source of the instability.

However, grid operator Red Eléctrica, along with numerous energy experts, has emphasised that renewables were not the root cause. Instead, the blackout exposes underlying weaknesses in the system’s ability to manage and balance these energy sources effectively.

One technical concern often raised in this context is the lack of mechanical inertia provided by solar and wind generation. Unlike traditional fossil fuel plants with large spinning turbines, most renewables don’t inherently provide inertia, which helps stabilise grid frequency.

While this is a legitimate engineering challenge, it’s also a well-known one—and grid planners have been increasingly addressing it with technologies such as synchronous condensers, energy storage, and fast-reacting demand-side management.

Importantly, the grid had successfully operated under similar conditions in the past. What changed was not the share of renewables but the specific sequence of events, including the fault location, inadequate redundancy, and limited interconnection with the broader European grid. Spain and Portugal are relatively electrically isolated from the rest of Europe, making it harder to import or export electricity during crises. This isolation can amplify the impact of even minor disturbances.

The blackout has reignited political debates in both countries. While some opposition voices have used the incident to critique the rapid transition to renewables, most energy professionals and government officials have instead called for accelerated investment in grid modernization. The key takeaway from this event is not that renewable energy is unreliable, but that the grid infrastructure needs to evolve in parallel with the energy transition. This includes building better forecasting systems, expanding battery storage, improving interconnectors, and developing flexible grid management technologies.

In short, blaming renewables for the April 2025 blackout misses the mark. The incident underscores the complexity of managing modern electricity systems and the importance of infrastructure readiness—not the unsuitability of clean energy. With the right tools and investments, renewable energy can continue to provide reliable, resilient, and sustainable power across the Iberian Peninsula and beyond.