Spain’s national power grid operator, Red Electrica de Espana (REE), underestimated the nation’s electricity demand on the day a mass blackout hit the Iberian Peninsula in April, an official government inquiry published Tuesday said.
Energy Minister Sara Aagesen confirmed that REE didn’t have sufficient thermal power plants running during the peak daytime hours of April 28, when a voltage spike caused a large-scale outage. “The system did not have adequate dynamic voltage control capacity,” Aagesen said in Madrid to reporters. “REE assumed additional thermal capacity wasn’t required after the early hours, which proved to be a major miscalculation.”
The blackout lasted for hours, causing pandemonium in big cities, stranding passengers in trains and elevators, and paralyzing traffic. The probe showed that some power stations, which were statutorily required to stabilize voltage levels, did not do so at a critical moment.
These plants were not only being tasked with regulating voltage fluctuations, but they were also being paid for it financially,” said Aagesen. “They did not draw the anticipated amounts of reactive power during the high-voltage incident.
Having a consistent frequency of 50 Hertz (Hz) throughout Europe’s electrical grid is vital to ensure operational stability. Even minor variations can ruin infrastructure. An increase in frequency generally means there is too much supply, whereas a decrease means demand outstripped supply. Here, the imbalance wasn’t corrected quickly enough to cause a cascading failure.
Even with the disruption, no proof was found by the inquiry of any cyberattack leading to the event.
A full report on the blackout will be issued later on Tuesday, providing a more in-depth examination of the series of mishaps. Authorities are now calling for better monitoring and readiness to avoid such grid misjudgments in the future.