A third 400 kV AC interconnection to Sweden

The transmission system operator Fingrid Oyj is, in cooperation with the Swedish transmission system operator Svenska kraftnät, planning a new transmission line from Pyhänselkä in Muhos via Keminmaa to Messaure on the Swedish side of the border. The background for the transmission line project is electricity market needs for additional capacity between Sweden and Finland. Cross-border capacity between the countries is often inadequate, which means that the electricity market cannot function efficiently and electricity prices diverge. In an import situation, this increases the price of electricity in Finland. Furthermore, insufficient connections endanger adequacy of electricity in Finland during exceptional situations.

In 2016, Fingrid and Svenska kraftnät completed a study on cross-border capacity development needs. In accordance with the Energy Authority’s Electricity Market Act (588/2013), the key starting point for the report is the system responsibility for the Finnish electricity system and development and connection obligations assigned to Fingrid as well as maintaining the quality of electricity at a sufficiently high level. According to the report, electricity transmission connections between Finland and Sweden are inadequate and so-called bottleneck situations are very likely also in the future, so a new transmission connection is needed. Various options for increasing electricity transmission capacity were examined, and a new alternating current connection from northern Finland to northern Sweden appeared to be the most feasible in terms of the national economy and also technically.

Position of the project as a PCI project

On 23 August 2017, Fingrid and Svenska kraftnät signed an agreement concerning the realisation principles for the new connection. The project was placed on the European Commission’s Projects of Common Interest (PCI) list on 23 November 2017. This status can be granted to projects that are essential for the EU's internal energy market and reaching the EU's energy policy objectives. The main objective of the EU's energy policy is affordable, secure and sustainably produced energy. The project promotes all of these main EU energy policy targets. The project’s PCI number and descriptions are:

4.10 Cluster Finland – Sweden [currently known as "Third interconnection Finland – Sweden"], including the following PCIs:

  • 4.10.1 Interconnection between northern Finland and northern Sweden
  • 4.10.2 Internal line between Keminmaa and Pyhänselkä (FI)

Project location and planning situation

With regard to Finland, the connection between Finland and Sweden will be implemented in two parts. The section between the Pyhänselkä and Keminmaa substations (PCI 4.10.1) will be completed first and, after clarification of the routing options on the Swedish side, will be followed by the section from Keminmaa to the Swedish border and on to Messaure substation in Sweden (PCI 4.10.2). A schematic diagram of the connection is presented in figure 1.

Kolmas yhdysjohto
Kolmas yhdysjohto

Figure 1 Schematic diagram of the third 400 kV transmission line connection Pyhänselkä-Keminmaa-Messaure

The EIA procedure is currently underway for the section between Pyhänselkä and Keminmaa, and a separate EIA will be performed for the section between Keminmaa and the Swedish border. The latter will start in 2018. Fingrid and Svenska kraftnät will make decisions on detailed further planning and construction after the environmental impact assessment has been completed. Construction of the transmission line is expected to last 2-3 years. In addition to the transmission line, the project will include substation expansions as well as one series-compensator in Finland and one series-compensator in Sweden. The common goal of Fingrid and Svenska kraftnät is to have the transmission line connection in use by the end of 2025.