Electricity had been restored to most of Spain and Portugal early on Tuesday after huge nationwide blackouts, although authorities were 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 on Tuesday morning, while Portugal's equivalent, REN, said that by late on Monday it had all 89 power substations in the country back up and running.
The authorities are now being pressed for an explanation of what caused one of the biggest power outages ever seen in Europe.
Spanish Prime Minister Pedro Sanchez said on Monday night the country had suffered a precipitous loss of 15GW of electricity generation in five seconds at around midday, equivalent to 60% 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 on Monday evening. Some areas in France suffered brief outages on Monday.
Spain is one of Europe's biggest producers of renewable energy, but Monday's shutdown has already sparked debate about whether the volatility of supply from solar or wind has made its power systems more vulnerable to such an outage.
John Kemp, an energy analyst and public policy specialist, said finding clear root causes for the sequence of failures that contributed to the blackout could take investigators several months.
"The region has one of the world’s highest penetrations of renewable generation from wind and solar so the blackout will be a case study of how renewable generators impact on reliability as well as restarting after widespread failure," he said.
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.
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”.
COUNTING COSTS
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.
Overnight, rail travelers were stranded in some of Spain's main hubs, as all trains were cancelled. In Madrid, some were forced to bed down overnight in the station or in the nearby Movistar Arena concert venue.
A state of emergency was declared across many Spanish regions on Monday, with the deployment of 30,000 police. In Atocha station in Madrid, police and Red Cross workers handed out blankets and bottles of water.
In Barcelona on Tuesday morning, restaurant owners counted the cost of lost produce after half a day of their fridges and freezers being off.
Maria Luisa Pinol, 63, owner of an establishment in the city, told Reuters late on Monday that she had been forced to temporarily close her doors.
"It’s impossible to serve food," she said. "(We’re) scared it will go bad, that we have to throw away everything away. We don’t know if the insurance will cover it, and, that's an economic loss besides other things too."