After over a decade's delay, the huge Finnish nuclear power plant Olkiluoto3 (OL3) went into commercial production on Sunday, making Finland almost self-sufficient in electricity supply.

According to the plant operator Teollisuuden Voima Oyj(TVO), OL3 is currently the largest in Europe and the third largest globally in terms of electricity production volume. With an output of 1600 Megawatt (MW) electricity, the new reactor will supply 14 percent of Finland's electricity demand.

TVO said that the entry of OL3 plant makes Finland almost self-sufficient in electricity supply. Combining the Olkiluoto 1 and Olkiluoto 2 plant units, almost a third of country's electricity is produced on the Olkiluoto island on Finnish west coast.

Jarmo Tenhua, chief executive officer of TVO, said that the facility would run at full capacity until scheduled maintenance in March 2024.

Originally planned to be operational in 2009, the OL3 was based on technology delivered by the French Areva and German Siemens.

The delay was one of the reasons for the major shortage of Finnish power production in recent years, professor Peter Lund of the Finnish Aalto University said when talking to the Finnish news agency STT.

Before the energy crisis of 2021, Finland routinely imported 20 percent of its electricity from abroad. The deficiency of domestic production emerged in the 2010s as Finland closed major coal-powered power plants.

Professor Lund said the launch of OL3 could somewhat reduce the price of electricity for consumers.