Norway's Seaway7 Begins Subsea Cable Laying at Hornsea 3 Offshore Wind Farm in the UK

en.Wedoany.com Reported - On November 12, Norwegian offshore engineering company Seaway7 announced that it had completed the laying of the first inter-array cable at the Hornsea 3 offshore wind farm in the UK North Sea, officially commencing subsequent subsea cable installation operations. The project has a planned installed capacity of 2.9 GW, and Seaway7 is responsible for the transportation and installation of 197 66 kV inter-array cables with a total length exceeding 536 km, connecting wind turbines to offshore converter facilities.

The construction is being carried out by the specialized cable-laying vessel Seaway Phoenix, with Seaway Moxie participating as a support vessel. Seaway Phoenix is responsible for cable loading, deployment, and offshore laying, while Seaway Moxie provides personnel transport and offshore construction support. Cable suppliers include Hellenic and Italy's Prysmian Group, with JDR Cable Systems responsible for inter-array cable testing and termination connections.

Inter-array cables form the collection network within an offshore wind farm, responsible for gathering and transmitting power generated by individual turbines to offshore electrical facilities. The cables being installed have a rated voltage of 66 kV, and the 197 cables will form a connection network covering the interior of the wind farm. Only after laying and subsequent connection and testing are completed can the power generated by the turbines be transmitted to the onshore grid through the offshore transmission system.

Hornsea 3 is located off the coast of Yorkshire and Norfolk in England, approximately 120 to 160 km from the coast, with water depths of approximately 25 to 75 m. The project plans to install 197 Siemens Gamesa SG 14-236 DD offshore wind turbines, each with a rated capacity of 14 MW. The project features two offshore converter facilities, using high-voltage direct current (HVDC) transmission technology to deliver power to shore.

Seaway7 previously participated in the Hornsea 1 and Hornsea 2 offshore wind projects developed by Ørsted in the UK North Sea. The Hornsea 1 project involved the installation of 89 inter-array cables totaling approximately 170 km; the Hornsea 2 project involved 165 cables totaling approximately 382 km. With construction now underway at Hornsea 3, Seaway7's total inter-array cable installation across the three Hornsea wind farm projects is expected to exceed 1,000 km.

Currently, the Hornsea 3 offshore wind project remains under construction, and Seaway7's inter-array cable installation work will be coordinated with turbine foundation installation, turbine installation, and offshore electrical facility construction. The project is expected to enter commercial operation in 2027.