NordLink Interconnector, Germany


NordLink

NordLink is a proposed bi-pole, high-voltage, direct current (HVDC) interconnector that will link the German and Norwegian power grids and connect the two main European electricity markets for the first time.

Designed to be Europe's longest interconnector, NordLink will be developed by Statnett (50%) in collaboration with TenneT (25%) and investment bank KfW (25%). The electricity generated from the project will be able to meet the energy requirements of 3.6 million German homes.

The project will also help in reducing carbon emissions by promoting the exchange of renewable energy and increasing the use of renewable in power generation. By utilising Norway's vast hydropower and Germany's wind and solar power, the interconnector will ensure an efficient and secure power supply.

An investment decision on the project was taken on 10 February 2015 and was followed by the groundbreaking ceremony for the construction of the German converter station on 16 September 2016.

The project is expected to be completed by 2019 and will start commercial operations in 2020 after completion of trial operations. Total cost of the project is estimated to be between €1.5bn ($1.68bn) and €2bn ($2.24bn).

NordLink Interconnector details

NordLink will enable Germany to export energy generated from wind and sun to Norway during the dry season, while Norway can export its surplus energy from hydropower to Germany during winters, which will help in facilitating the integration of the European energy market.

The 623km-long cable will have a planned capacity of 1,400MW and will connect the continental ENTSOE grid and the Nordic grid, having an installed capacity of 600GW and 100GW respectively.

The interconnector will consist of 54km of underground cable route in Germany, 516km of submarine cable route and 53km of overhead line in Norway. Its planned route will be between Tonstad / Ertsmyra in Sirdal municipality in Norway and Wilster in Schleswig-Holstein in Germany.

The HVDC system will comprise a bipole configuration with a rating of ±525kV. The converter stations will be located in Wilster and Tonstad, where electricity will be converted between direct current and alternate current and supplied to the transmission grids, for distribution to homes and businesses.

Details of NordLink Interconnector cable system

"The electricity generated from the project will be able to meet the energy requirements of 3.6 million German homes."

Subsea cables in Germany will be buried at a depth of approximately 25m and will comprise two parallel mass impregnated cables. They will be installed in a bundled configuration to ensure minimum impact on magnetic marine compasses.

The submarine cables will be equipped with a copper conductor, as well as a paper insulation system and double-steel wire covering. The cable will have an outer diameter of 15cm.

The underground cables will be similar to the subsea cables but will not have a wire covering and will be equipped with an extruded polyethylene (PE) sheath. The cables will be joined onsite and will be delivered in lengths of approximately 1km on cable steel drums.

Contractors involved

Nexans was awarded a €500m ($560m)-worth contract to design, manufacture and install two 525kV cable subsystems. It will also design, manufacture and install mass impregnated non-draining (MIND) HVDC cables at depths of 450m using cable-laying vessel, C/S Nexans Skagerrak. Nexans will use its Capjet system for trenching the cables on the seabed for protection.

A $900m-worth contract for the HVDC converter stations and the cable system in Germany was awarded to ABB. The scope of work includes design, engineering, supply and commissioning of two 525kV, 1,400MW converter stations using its Voltage Sourced Converter (VSC) technology.

ABB will also design, manufacture and install a 525kV mass impregnated cable system in the German sector that will encompass 154km of subsea and 54km of underground cable.