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. 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 socio economic benefit and also technically. On 23 August 2017, Fingrid and Svenska kraftnät signed an agreement concerning the realisation principles for the new connection.

Important European project

The expansion of the Finnish-Swedish high-voltage interconnection is included on EU’s list of important infrastructure projects – so-called Projects of Common Interest (PCI) – which are deemed essential to the integration of the European electricity grids. As a result, the project has received EU funding.

Learn more about PCIs.

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 4.10.2) 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 4.10.1). The route alternatives of the connection are presented in figure 1.

Figure 1 The planned route of the transmission line in Finland and the route alternatives being analysed in Sweden. You can zoom in on the picture on mobile device.

The Environmental Impact Assesment (EIA) procedure was finalised in January 2019 for the section between Pyhänselkä and Keminmaa, and the EIA is underway for the section between Keminmaa and the Swedish border. The latter will be finalized in 2020. EIA will be coordinated with the Swedish routing and environmental analysis. Fingrid and Svenska kraftnät will make decisions on construction after the environmental impact assessment and further planning and 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 expansion in Messaure, Sweden and Pyhänselkä, Finland, a new substation in Keminmaa, Finland, one series-compensation station in Sweden and one series-compensation station in Finland. The common goal of Fingrid and Svenska kraftnät is to have the transmission line connection in use by the end of 2025.