That was due to the severe cold in Russia which threatened power supplies in the St. Petersburg area -- a metropolitan region with roughly the same population as Finland.

On Thursday UES cut supplies to Finland from 1,400 to 800 megawatts. Finland used reserves and imported more electricity from Sweden to make up for the shortfall.

Freezing conditions have pushed electricity consumption to record levels. Power grid operator Finngrid has already advised consumers not to excessively use power during the morning and evening peak periods. However, there is no actual risk to electricity supplies.

This winter's record cold was recorded early Friday in the village of Pokka in Kittilä, Finnish Lapland, where the mercury sank to -42.6 degrees Celsius.