Electricity has been restored to most of Spain and Portugal after huge nationwide blackouts, although authorities are still trying to find out what caused the sudden outage.
In Spain, schools and offices reopened, public transport restarted after long delays, traffic gridlock eased and many hospitals had recovered power while others continued to operate on generators.
Spain's electricity grid operator Red Electrica said it was able to supply virtually all of the country's electricity demand early on Tuesday as the system gradually recovers from a nationwide blackout on Monday.
All of Spain's substations were operating on Tuesday morning, Red Electrica said in a post on X social media.
"We keep on working from centre of electric control to secure total normalisation of the system," it added.
The Madrid underground metro network said it had resumed operating with 80 per cent of trains circulating, but railway infrastructure operator Adif said most trains nationwide were not operating.
The outage hit most of the Iberian Peninsula on Monday morning, bringing Spain and Portugal to a standstill.
As the metro service stopped, train stations cleared out and shops and offices closed, and thousands of people spilled onto the streets of Madrid. Some resorted to hitchhiking. Others walked hours just to get home.
Spanish national TV broadcast images of commuters clambering out of stalled trains in unlit tunnels.
The cause of Monday's blackout was unclear with authorities being pressed for an explanation of what caused one of the biggest power outages ever seen in Europe.
The governments of Spain and Portugal announced crisis meetings on Tuesday to assess the situation.
Prime Minister Pedro Sanchez said Spain had suffered a loss of 15GW of electricity generation in five seconds, equivalent to 60 per cent of national demand.
The grid instability caused the Spanish and French electricity interconnection through the Pyrenees mountains to split, resulting in a general collapse of the Spanish system, Red Electrica's chief of operations Eduardo Prieto told reporters.
Some areas in France suffered brief outages on Monday.
In Portugal, the government said hospitals were back up and running, airports were operational albeit with hangover delays in Lisbon, while the capital's metro was restarting operations and trains were running.
The government said all 6.4 million electricity clients had power supplies normalised after Monday's country-wide blackout.
Schools were also reopening and the health service fully stabilised.
Marc Ferracci, the French Industry Minister, told RTL radio station on Tuesday that France was better prepared to prevent blackouts such as the one suffered by Spain and Portugal and that the impact in France had been "minimal".
Madrid's authorities put on free buses to get people to work on Tuesday and the metro and some trains started to operate, although with delays.
with AP