MADRID: Spain and Portugal were hit by a widespread power blackout on Monday (Apr 28) that paralysed public transport, caused large traffic jams and delayed airline flights, and left utility operators scrambling to restore the grid.
Although nothing was off the table, there was no indication that the outage was caused by a cyberattack, said Portuguese Prime Minister Luis Montenegro.
He said the authorities were trying to restore the situation in the next few hours, but Portuguese utility REN said fully normalising the network could take up to a week.
It said the power supply interruptions in Portugal were caused by a fault in the Spanish electricity grid, related to “a rare atmospheric phenomenon”.
“Due to extreme temperature variations in the interior of Spain, there were anomalous oscillations in the very high voltage lines, a phenomenon known as ‘induced atmospheric vibration’,” it said.
“These oscillations caused synchronisation failures between the electrical systems, leading to successive disturbances across the interconnected European network.”
It added: “Due to the complexity of the phenomenon and the need to rebalance electricity flows internationally, it is estimated that full normalisation of the network could take up to a week.”
The outage caused chaos in parts of Portugal and Spain as traffic lights stopped working, causing gridlock. Transport networks were halted, hospitals were left without power and people were trapped in the metro and in elevators.
In Madrid, hundreds of people stood in the streets outside office buildings and there was a heavy police presence around some important buildings, with officers directing traffic as well as driving along central atriums with lights.
