Final Report Finds Voltage-Control Failures Drove 2025 Iberian Blackout

Overview

• The investigation by 49 experts rejects a single root cause, describing a perfect-storm interaction of technical, operational and regulatory weaknesses in what ENTSO‑E calls Europe’s most serious power-system failure in more than two decades.
• Ineffective voltage management produced oscillations and overvoltages that led to widespread shutdowns, especially of wind and solar connected through power‑electronics converters.
• Shortcomings cited include improperly configured renewables, slow manual responses at conventional plants, a wider 400 kV voltage range that reduced safety margins, and Red Eléctrica’s lack of real‑time risk tracking under insufficient rules.
• The report recommends automated voltage control, active grid‑stabilization requirements for wind and solar, real‑time threshold monitoring, and penalties for plants that fail to provide promised support, and it notes some early disconnections remain unexplained.
• The outage began at 12:33 local time on April 28, 2025, cutting electricity and dependent services for hours and disrupting flights at major airports in Madrid, Barcelona and Lisbon.