Transport and installation of 315 km of 66 kV inner array grid cables for HKZ 1-4.
Subsea 7 was awarded a substantial contract by Vattenfall for offshore installation works on the Hollandse Kust Zuid (HKZ) 1–4 offshore wind farm, located 18–36 km off the Dutch coast in the North Sea. The contracted scope included marine transportation and offshore installation activities for two core balance-of-plant elements: the wind turbine monopile foundations and the 66 kV inner-array (inter-array) cable network that interconnects turbines and connects them to the offshore high-voltage stations. Subsea 7 stated that its scope covered the transport and installation of approximately 140 wind turbine monopile foundations, as well as the transport and installation of 315 km of 66 kV inner array grid cables, in water depths of approximately 18–27 metres. Offshore execution was scheduled across 2021 and 2022, using Seaway 7 heavy lift, cable-lay and support vessels. This award related to the construction phase of HKZ and positioned Subsea 7 as a key offshore installation contractor for both foundation installation and infield cable installation. Subsea 7 noted the contract was subject to a final investment decision by Vattenfall, after which it would be included in backlog.