Doubled capacity and a new link to Norway was the decision of Svenska Kraftnät’s Board at an extra meeting on January 17th as a step towards adapting the Swedish and Nordic transmission grids to the European energy and environmental politics of the future. The growth in wind power generation will in particular create a need for increased capacity and flexibility in the electricity transmission grids. The decision means that the optimal combination of HVAC (high voltage alternating current) and new HVDC (high voltage direct current) technology will be applied.

There is already a decision to construct the Southern Link (Sydlänken). This will now be part of a larger infrastructure project, the South-West Link. The capacity is doubled compared to previous plans. Thanks to the extended project, bottlenecks in the national grid on the Swedish west coast and on the interconnection with southern Norway will also be alleviated.

“We have chosen the technology which can both provide maximum capacity and flexibility for the future. By constructing an connection to Norway at the same time, we will now solve a number of problems which have inhibited the efficiency and competition in the Nordic electricity market.” said Chairman of Svenska Kraftnät’s Board Sven Hulterström and acting Director General Sture Larsson.

The South-West Link will be constructed in three sections. From a switching station close to the town of Jönköping och southwards to the province of Skåne a new HVDC technology with underground cables will be used. The link to Norway will be constructed with the same technology and will be connected to the station near Jönköping and to the Norwegian national grid, west or north of the Oslo fiord. Subject to necessary decisions being taken in Norway, the Norwegian Transmission System Operator Statnett will be responsible for the part of the link on the Norwegian side of the border.

In the northern section from the province of Närke och southwards to the station near Jönköping, a new HVAC power line will replace an existing line and will use the same power-line corridor. When passing by sensitive areas, e.g. near to the town of Motala, special consideration will be given to the local environment.

The project is a challenge as it involves constructing the world’s first installation using this new technology on the doubled capacity level. Svenska Kraftnät and Statnett look forward to the manufacturers of the HVDC components being able to construct a project with such a high capacity.

Svenska Kraftnät’s Board decided on 25 November 2005 to construct the Southern Link to reinforce the Swedish national transmission grid between Närke and Skåne. The purpose of the link was both to increase the transmission capacity and the robustness of the grid. The Southern Link is one of five strategic projects which the Nordel collaboration has agreed upon in order to reinforce the Nordic electricity transmission grids.

The choice of technology for the link was not defined at that time, but was to be determined from subsequent investigations. The choice has mainly been between a conventional HVAC overhead line, such as in the rest of the grid, and new so-called “HVDC VSC”technology (Voltage Source Converter) with underground cables. No decision regarding choice of technology had been taken until the Board meeting of 17 January 2008.