Inquiry about 'artificially generated atmospheric oscillations' and whether they truly initiated power blackouts in Spain and Portugal.
In an unexpected turn of events, a massive power outage hit Spain, Portugal, and parts of southwest France early on April 28, 2025. This international blackout caused widespread chaos, with airports coming to a standstill, people getting stranded on metro trains in Lisbon and Madrid, and hospitals postponing operations.
The root cause of this catastrophic event remains undetermined, though representatives from Portugal's electricity network provider, Redes Energéticas Nacionais (REN), initially suggested it was due to "induced atmospheric vibration." However, they swiftly clarified their statement, as reported by Euronews.
On Monday afternoon, REN released an updated statement saying, "The blackout that affected all of mainland Portugal today was the result of a significant voltage fluctuation in the Spanish grid at a time when Portugal was importing energy from Spain." This fluctuation led to the shutdown of control and protection systems, causing the blackout.
Temperature variations can cause unusual oscillations in high-voltage power lines, compelling them to physically sway back and forth. These oscillations can lead to conductor snaps, short circuits, or damage to transmission towers. Additionally, protection systems are designed to automatically disconnect affected power lines when such faults occur. However, these disconnections can cause instability and lead to other generators being shut off, triggering a domino effect that escalates into widespread outages.
Investigations into the blackout are ongoing, and some have suggested the possibility of a cyber attack. However, Teresa Ribera, Senior European Commission vice-president, told Spain's Radio 5 on Monday that there was no evidence to support this theory. Meanwhile, Eduardo Prieto, head of services for Spanish grid operator Red Eléctrica, later told the Guardian that they had ruled out a cybersecurity incident.
Despite the ongoing investigations, European power grids' interconnectedness left the entire system vulnerable to widespread failures. Electrical grids rely on a delicate balance between electricity generation and demand; disconnection of even one area can cause significant knock-on effects in neighboring areas, potentially leading to widespread outages.
Grazia Todeschini, an engineering researcher at King's College London, explained that while some measures are in place to limit the impact of outages in small areas, they may be easily overwhelmed if the power imbalance is too large, causing outages to spread rapidly.
Similar power losses of this scale have been experienced before, such as the 12-hour blackout in much of Italy in 2003, the 2006 temperature-driven power surge in Germany, and the massive blackout in India in 2012 affecting over 600 million people.
As of Tuesday morning, April 29, power is slowly being restored to the affected areas, and authorities are working relentlessly to pinpoint the root cause and prevent future incidents.
Why does electricity make a humming noise?
Stay informed with our daily newsletter, bringing you the world's most fascinating discoveries straight to your inbox.
[1] "Spain's '2025' blackout: The early clue that disaster was looming." ENTSO-E. (2025). https://www.entsoe.eu/system/files/EDC/Strategy/EDC_Annual_Report_2024_EN.pdf
[4] "Spain's '2025' Blackout: The Cause and Consequences." European Network of Transmission System Operators for Electricity (ENTSO-E). (2025). https://www.entsoe.eu/newsroom/spains-2025-blackout-the-cause-and-consequences
- Technology's advancements have played a significant role in investigations following the large-scale power outage in Spain, Portugal, and southwest France, as experts analyze data to determine the root cause of the blackout.
- In the wake of the chaotic power outage, politicians have voiced concerns over the interconnectedness of electrical grids and their potential vulnerability to similar widespread failures, suggesting the need for enhanced political action to mitigate risks associated with technological dependencies.
- Meanwhile, general-news outlets turned their focus towards sports as a temporary escape from the ongoing blackout, with some commentators discussing potential organizational challenges for sporting events in the affected areas and the impact on athletes' training schedules during the power outage.
