Low-carbon electricity in Finland was so abundant this week it sent energy prices briefly into negative territory, Jukka Ruusunen, chief executive officer of Finland's grid operator Fingrid told public broadcaster Yle.

The Nordic country, which recently announced commercial operation of a new nuclear power plant, reported that its spot energy prices dropped below zero before noon.

Ruusunen told Yle on Wednesday (24 May): “The average price for the day is now slightly, but nevertheless, on the negative side. Yes, it is historic.”