Spain’s government has released a detailed report pinpointing the causes of the April 28 Iberian Peninsula blackout, which cut power to approximately 60 million people across Spain and Portugal. The investigation concluded there was no evidence of a cyber-attack; instead, a complex chain of technical failures and operational shortcomings led to the widespread outage.
Environment Minister Sara Aagesen summarized the findings: “Surging voltages triggered cascading disconnections when the grid failed to regulate dynamic voltages due to insufficient operational thermal power plants and poor performance by certain voltage management companies.” This led to system-wide collapses affecting electricity, transport, communications, and banking.
A 49-day investigation led by Minister Aagesen held Red Eléctrica de España (REE) and several utilities responsible for “bad planning” and operational errors. Key issues included ignoring scheduled replacements at voltage regulation plants and unintended automatic shutdowns of substations essential for managing reactive power—faults that ultimately disconnected Spain from the wider European grid.
The blackout, which began with voltage fluctuations and mismatch in reactive power, escalated in mere 12 seconds, wiping out a staggering 15 gigawatts—around 60% of Spain’s power supply. Investigators found no evidence of external attacks; however, the probe flagged cybersecurity vulnerabilities at smaller power generators as a potential risk.
The absence of a single failure and the grid’s inability to contain reactive voltage swings underscored systemic fragility in Spain’s evolving energy mix—which now includes nearly 60% solar and 12% wind, a significantly higher dependency than in past years.
As a corrective response, the report recommended enhanced supervision, infrastructure upgrades, stricter compliance measures, and improved cybersecurity protocols. Minister Aagesen emphasized the need for stronger monitoring and renewal of aging equipment, stating it was a robust factual analysis—not a blame exercise.
Prime Minister Pedro Sánchez defended Spain’s commitment to expanding renewable energy, noting the outage occurred under severe but unanticipated grid stress—not because of the energy transition.
