Red Eléctrica has denied that a cyberattack was the cause of the power outage, however, Spain’s High Court has not yet completed its investigation, Euronews reports.
Spain’s national electricity grid, Red Eléctrica, has assured, through its president, that the blackout will not happen again and that what happened was not a mistake on the company’s part. Beatriz Corredor also explained that “linking Monday’s serious incident with the rise of renewable energy is not correct” and said that the Spanish electricity system is “the best and most resilient in Europe”.
Corredor denied the theory that the blackout was caused by a cyber attack, but confirmed that Spain’s High Court is still investigating this possibility. The Spanish government gave Red Eléctrica until late Wednesday afternoon to report its findings.
The Iberian neighbor is also investigating the event and Portugal’s National Emergency and Civil Protection Authority (ANEPC) said it “still does not know the cause of the blackout”. The agency’s president, José Manuel Moura, told reporters on Wednesday that there were “no victims” in Monday’s power outage.
What is known about the blackout
About three hours before the blackout, power quality sensors in homes in the Madrid area showed warning signs of an unstable grid. There were small fluctuations in voltage around 9:30 a.m. local time, according to Bob Marshall, CEO of Whisker Labs, which has sensors in homes in and around Madrid where it tests technology for preventing residential fires and monitoring the power grid.
Marshall says the data shows there were oscillations whose frequency and magnitude increased over the next three hours until the grid failed. Around noon, there was a large increase in the magnitude of the fluctuations, with the measured voltage rising and falling by about 15 volts every 1.5 seconds.
“The way I would interpret our data,” Marshall explains, “is that the power grid is struggling. Something is wrong. And it’s showing increasing signs of instability.”
It was just after 12:30 p.m. when Spain lost 15 gigawatts of electricity. This is equivalent to 60% of the demand in the country of 49 million inhabitants. Data provided by Prime Minister Pedro Sánchez.
According to Spain’s electricity grid operator, Red Eléctrica, there were two significant “disconnection events” — power outages — before the power outage. The Spanish grid managed to recover from the first event, but the second was more damaging, progressing to the point of causing interruptions in the French electrical system and producing “a massive and temporary disconnection”, as explained by the director of systems operations, Eduardo Prieto.
Europe’s electricity grid is highly connected, which means it can pool energy between countries and can make the system more resilient. However, it means that an outage in a major transmission artery or a frequency imbalance could trigger cascading protection outages between countries, according to Shreenithi Lakshmi Narasimhan, a fellow at the Institute of Electrical and Electronics Engineers.
Spain and Portugal are connected to Europe’s main electricity grid through France and the sudden power outage caused an interconnector between Spain and France to trip, hence the blackout affecting French territory.
What is not known about the blackout
Neither Spanish nor Portuguese authorities know exactly what caused the fluctuations and eventual power outage.
“There are a variety of things that often happen at the same time and it’s very difficult for any one event to say ‘this was the root cause’,” said Eamonn Lannoye, managing director of the Electric Power Research Institute. According to Lannoye, there are a number of events that could explain grid failures, including the shutdown of power lines or generators in some locations for maintenance. “I think it’s fair to say this could be a really complex event,” he said.