Portugal and Spain have been hit with nationwide black outs, with parts of south-west France also affected.
The outages left as many as 60 million people without power on Monday, with no clear cause emerging yet.
Spain's Interior Ministry declared a state of emergency following the outage and said the status would be applied to regions that request it, which so far include Madrid, Andalusia and Extremadura, who have all asked for the central government to take over public order.
According to Spanish Prime Minister Pedro Sanchez around half of the country has now had their power restored, partially due to electricity assistance from France and Morocco. However, Portugal remains without power.
"Citizens can and should be calm," Sanchez said.
“We have a clear goal and it is to get power fully restored by tomorrow.”
The blackout saw all digital services down, including phone lines, power to shops disrupted and railways halted, with videos emerging of those in Spain cheering as power returns piece by piece.
In the Madrid region emergency services workers also performed 286 rescue operations to free people trapped inside elevators, the regional government head reported.
