Nordic power system and interconnections with other systems
Finland’s main grid is part of the synchronous inter-Nordic system, which includes the transmission grids of Sweden, Norway and eastern Denmark, in addition to Finland. The Nordic system is interconnected with other countries through several direct current (DC) transmission connections. There are a number of DC connections to western Denmark (Jutland) from Sweden, Norway and Eastern Denmark. DC connections run from Sweden to Germany, Poland and Lithuania. There is a DC connection from Norway to the Netherlands, and from Finland to Estonia and Russia.
Finland’s main grid is connected to the Swedish grid via two 400 kV alternating current (AC) connections in northern Finland. Finland also has a 220 kV AC connection to Norway. In addition to the AC connections, DC links have also been built: Fenno-Skan 1 from Rauma (400 MW) to Dannebo, Sweden, and Fenno-Skan 2 (800 MW) from Rauma to Finnböle, Sweden. There is a 100 MW DC connection from Naantali to the Åland Islands; that connection is owned and operated by Kraftnät Åland.
The Russian and Estonian grids do not have AC connections with the Nordic grid. Finland and Estonia are connected by the DC links Estlink 1 (350 MW) and EstLink 2 (650 MW). There are three 400 kV transmission links from Finland to Vyborg, Russia. Russia and Finland are also connected by 110 kV connections from Ivalo and Imatra in Finland. These enable the connection of hydropower plants in Russia to the Finnish grid.
The TSO of Norway, Statnett, maintains a map which shows the state of the Nordic power system. The map can be found from Stattnet's pages here.