On April 28 at 12:32 PM, an unexpected blackout left all of Spain without electricity, also affecting regions of Portugal and France in an unprecedented event in Europe. The outage lasted for hours, causing great uncertainty among the population. The causes are still under investigation.

 In the midst of the information surge, representatives from the renewable sector advocated for caution, avoiding falling into rumors, and explained that at the time of the blackout, Spanish renewable plants over 2 MW disconnected from the grid due to a frequency disturbance, for safety reasons. That is, the disconnection that occurred—just as with nuclear plants and other technologies—was a consequence, not the cause, of the event.

Even the president of Redeia, Beatriz Corredor, stated that 'renewables are not the cause' of the massive power outage on Monday. Corredor, who leads Redeia, the parent company of Spain's electrical system operator, Red Eléctrica, distanced the blackout from renewable energy generation, clarifying that the issue lies elsewhere.

To analyze this blackout at the European level and go beyond Spain's borders, Review Energy interviewed Kristian Ruby, Secretary General of Eurelectric, who acknowledged that we are facing an event that occurs once every 50–100 years.

Responding to the question of whether Europe should move towards greater regulatory harmonization or even more centralized energy governance, Ruby points out that from the network's perspective, they do not recommend moving in that direction.

“Considering the vast diversity in network topology, modernization, and investment needs across Europe, we need specific regulatory frameworks that incentivize investments tailored to the needs of each grid. However, we strongly advocate for more investments in physical and cyber resilience of networks, both at the national and cross-border levels,” Ruby emphasized.

When it comes to existing mechanisms to prevent a "domino effect" when failures occur in different regions, the Secretary General of Eurelectric explained that “typically, electricity grids are built under the n-1 principle, meaning that almost all energy users are connected by more than one line. Thus, if an asset or component unexpectedly fails, the automatic protocols of the system operator redirect the current through another line, allowing the system to continue functioning and customers to remain supplied.”

This principle, he added, ensures reliability by preventing widespread blackouts, resilience by allowing rapid adaptation after a failure, and stability by maintaining frequency, voltage, and system synchronization.

Ruby agreed that the exact causes of this blackout will only be known after a detailed technical analysis, which could take weeks, even months.

Despite the magnitude of the event in Spain, Ruby defended the resilience of the continental electricity system. “Thanks to existing protocols, we did not have a large-scale blackout outside Iberia. Spain disconnected from the continental grid, and only minor impacts were recorded in France,” he commented.

Electricity interconnections: A safeguard or a shared vulnerability?

According to the Secretary General of Eurelectric, electricity interconnections are crucial for strengthening energy security across Europe. “A higher level of interconnection helps ensure access to diverse electricity sources and a secure 24/7 supply. Interconnected electricity grids, along with robust distribution networks reaching deep into local markets with distributed energy resources, ensure that no region is left without sufficient supply, sharing the benefits of each Member State’s energy mix.”

Additionally, he warned about the vulnerabilities faced by countries with fewer interconnections, such as Portugal. “Without access to other resources, poorly interconnected countries are more vulnerable to system disruptions, whether due to unexpected supply or demand shifts, deliberate attacks, or extreme weather events,” he noted.

Ruby concluded that as we move towards a system with higher rates of variable renewable energies, it is vital to better leverage flexibility technologies like battery energy storage systems and pumped hydro storage, as well as grid-enhancing and grid-forming technologies. These will be key to maintaining grid balance during periods of low renewable generation.