Spain's grid operator, Red Eléctrica, has officially ruled out cyber interference as the cause behind the significant power outage that impacted not only Spain but also Portugal and parts of France. During a briefing, operations director Eduardo Prieto emphasized that preliminary investigations have shown "no kind of interference in the control systems," a sentiment echoed by Portuguese Prime Minister Luís Montenegro the previous day. However, the investigation remains ongoing, and officials have stated they "cannot draw conclusions" until more detailed data is available.
The power cut, which occurred on Monday, left Prime Minister Pedro Sánchez asserting that efforts were underway to identify the cause and implement preventive measures for the future. As investigations continue, details about the outage are gradually emerging, leading experts to propose several potential explanations for the incident.
One possibility that has surfaced pertains to the interaction of renewable energy within the grid. During the crisis, Sánchez noted a sudden loss of 15GW of power—about 60% of demand—within just five seconds. Prieto discussed two distinct "disconnection events" occurring in rapid succession in south-western Spain, an area known for its substantial solar power output. Despite concerns regarding renewable sources, Sánchez clarified that the incident does not stem from an excess of renewable energy supply, given the low electricity demand preceding the malfunction.
The dynamics of electricity supply and demand are complex, and discrepancies can lead to frequency fluctuations within the grid, a risk identified by Prof. Hannah Christensen of the University of Oxford. Rapid responses from power companies, in an effort to protect equipment from frequency deviations, can trigger a domino effect, resulting in a widespread blackout. Even with advanced predictive capabilities for renewable energy production, Christensen highlighted the inherent unpredictability of these energy sources.
Experts also considered the significance of Spain's electrical connections with France, which may have contributed to the outage. The reliance on just a few interconnections, compounded by the geography of the Iberian peninsula, makes it more susceptible to grid failures. Quick restoration of service was accomplished through connections to France and Morocco, as well as utilizing gas and hydropower resources.
Earlier speculation suggested the outage may have been linked to an unusual atmospheric event; however, Portugal's grid operator later retracted these claims. Despite the elimination of cyber interference as a causative factor, the investigation into the power cut will delve deeper, as uncertainties about its real cause continue to be scrutinized.
