NordBalt, The Baltic Sea

NordBalt is a joint project of the Swedish and Lithuanian TSOs (transmission system operators) Svenska kraftnät and Litgrid AB. It is part of Lithuania’s long-term strategy to secure its energy independence by interconnecting the power grids of the Baltic countries with other grids.

References
NordBalt, The Baltic Sea

Key Facts

Client

Svenska kraftnät, Sweden and Litgrid AB, Lithuania

Total cable route length

453 km

Location of the project

The Baltic Sea (Sweden-Lithuania)

Duration

2010 - 2015

Quantity of order

Turnkey ±300 kV DC cable system solution with a 700 MW power rating

Scope

HVDC cable system, including 2x400 km XLPE submarine HVDC cable, 2x40 km XLPE underground HVDC cable and 2x13 km XLPE underground HVDC cable
Cable system design and engineering
Cable system manufacturing
Submarine and underground cable-laying and installation
Project management, testing and commissioning

The project

The NordBalt HVDC link interconnects the power grids of Lithuania, Latvia and Estonia with those of the Nordic countries.

The interconnection enables the emerging electricity market of the Baltic countries to integrate with other electricity markets. This improves competition and provides alternative sources of electric power.

The sea crossing calls for a secure and environmentally friendly HVDC cable system installation for connecting the transmission systems. This is important since the cable route passes through former mined areas and explosives dumping grounds as well as a Natura 2000 nature protection area on the Lithuanian side.

The solution

We provided a HVDC cable interconnection for the transfer of power in either direction between the two power grids on each side of the Baltic Sea.

The cable system with submarine and underground cables offers several special features and compelling environmental benefits, including low losses, network stability, neutral electromagnetic fields, oilfree cables and minimal visibility. It is also designed for integration into a future pan-European grid.

Our solution is built on extensive knowledge and experience, and includes system design and engineering, onshore and offshore installation, testing and commissioning.

The cable system has a power rating of 300 kV. It comprises a 2x400 km long HVDC submarine cable across the Baltic Sea, a 2x40 km HVDC underground cable to Nybro on the Swedish side and a 2x13 km HVDC underground cable to Klaipeda on the Lithuanian side. At the time of installation, it was by far the world’s longest extruded power cable system.