Cable supplier, Nexans, has won a €50m plus contract to supply a total of 57km high voltage subsea power export cables to Northwind NV in the North Sea.

The project comprises 14km of cable to connect Belwind Phase 2 to the Northwind wind farm (formerly known as Eldepasco), together with a further 43km of cable that will transfer a total of 381MW produced by both wind farms to the onshore grid connection at Zeebrugge.

In addition to the design, type testing and supply of the XLPE subsea cables, Nexans will also supply mechanical and electrical accessories. This includes the onshore transition joints to connect the subsea cables to the land cables, the accessories for the two platforms, comprising hang-off and GIS (gas insulated switchgear) terminations, and four repair joints.

The Northwind wind farm will comprise 72 wind turbines, summing up to a total of 216MW installed capacity. The power will be delivered to the Belgian electricity network at the ELIA HV connection station in Zeebrugge.

The 14km section of 245kV cable connecting Belwind Phase 2 to Northwind will consist of three copper cores, each with a cross section of 400mm2.

The majority of the 43km, 245kV connection from Northwind to Zeebrugge will comprise of three 1000mm2 copper cores. However, there is a length of the route where the cable has to traverse a sea channel subjected to regular dredging, requiring it to be buried down to nine metres in the seabed for protection.

In order to maintain the electrical performance of the cable along this channel, the copper cross section will be increased to 1,200mm2 on a 4km section. This section of cable will have an outer diameter of 265mm and will weigh 130kg per meter.

The subsea cables will be manufactured at Nexans’ specialised facility in Halden, Norway. They will also include two FO48 fibre optic elements, manufactured in the Nexans Rognan plant, to enable data communications, control and monitoring for the power transmission system.

“Following the success of our cable contract for Belwind Phase 1, we are delighted to have been awarded the contract to supply high voltage power cable for Northwind offshore wind farms,” said Dirk Steinbrink, executive vice president High Voltage & Underwater Cables Business Group of Nexans.