Offshore

Installation in the North Sea

Offshore construction is expected to begin in 2022 with contractors using specialist vessels to install the offshore infrastructure.

The first phase, Dogger Bank A, is expected to be operational in 2023.

Cable installation

Offshore wind farms have two distinct offshore cable requirements, the first being the ‘inter-array’ cable network within the wind farm itself and the other being the subsea ‘export’ cables which take the generated electricity from the wind farm to shore.

Specialist cable laying vessels will be used to install and bury the subsea cables within the site and along the export cable route to shore.

Inter-array cables

The inter-array cable network consists of a large number of subsea cables which inter connect the turbines to the offshore HVDC converter platform.  The installation and connection of the cables to the turbines requires the use of specialist teams and vessels to:

  • Clear each cable route of obstruction
  • Dig trenches to a depth of around 1.5m in which to lay the subsea cables
  • Lay and bury the subsea cables
  • Connect the cables to the turbines and to the offshore converter platform

At its highest extended point, the Voltaire turbine installation vessel stands taller than the Eiffel Tower

Converter platforms

Our contractors will construct a converter platform within each wind farm which will take the electricity generated by the turbines and convert it from AC current to High Voltage Direct Current (HVDC) before the power passes through the adjacent main substations and on to the National Grid.

Turbines

The installation of the turbines at Dogger Bank A and B will require the use of specialist installation and support vessels.

The monopile foundations will be installed in the seabed with a transition piece fitted, providing a stable and secure platform on to which the turbines can be fixed.

Once manufactured, the turbine components will be delivered to a marshalling and construction facility at Able Seaton Port on the north east coast of England.

The components will then be loaded aboard the Voltaire, the world’s largest specialist heavy lifting jack up vessel, and shipped to the wind farm for installation and commissioning.

Dogger Bank A and B will feature 190 of the world's largest offshore wind turbines – GE's Haliade-X

To find out about onshore construction works click here.

ONSHORE