Dudgeon Offshore Wind Farm, United Kingdom

The 402MW Dudgeon offshore wind farm, being developed in the UK North Sea, approximately 32km off the coast of Cromer in North Norfolk, will be one of the world's biggest offshore wind farms when completed. Holding a 35% stake in the project, Statoil will be the operator, while Masdar owns 35% and the remaining 30% is held by Statkraft.

Construction of the £1.5bn ($2.5bn) wind farm began in March 2015, with commercial operations expected to start in the second half of 2017. The project will create approximately 70 jobs during its operations.

The wind farm will annually produce approximately 1.7TWh of clean energy, which will power approximately 410,000 UK households. It will also offset 19 million tonnes of carbon dioxide emissions from the atmosphere over its 25-year lifetime.

Dudgeon wind project background

"Statoil and Statkraft acquired the project from Warwick Energy in 2012."

The UK Government granted the licence for a 560MW offshore wind farm development at the Dudgeon site during the Round II allocation in 2003. The project received planning consent from the Department of Energy and Climate Change (DECC) in 2012.

Statoil and Statkraft acquired the project from Warwick Energy in 2012 and reviewed the design, eventually reducing the generating capacity to 402MW. The revised proposal was approved by the DECC in December 2013.

Wind farm turbine details

The Dudgeon offshore wind farm will feature 67 Siemens 6MW wind turbines installed on monopile foundations at water depths ranging between 18m and 25m.

Each turbine will have a rotor diameter of 154m and 75m-long rotor blades, manufactured using single-cast Siemens Integral Blade production technology.

The turbines will rest on monopiles with a diameter between 7m and 7.4m, and weighing between 800t and 1,200t. The operations and maintenance base for the wind farm will be situated at Great Yarmouth Port's river harbour.

Power transmission from Dudgeon wind farm

The power generated by the offshore wind farm will be transported to the shore at Weybourne Hope on the North Norfolk coast via a 38km-long, 132kV seabed cable. A 48km-long underground cable will subsequently transfer the electricity to the Necton substation, which is to be built near Swaffham Town, Breckland, Norfolk. From here, the power will be transmitted to the National Grid network via a 400kV overhead line.

Dudgeon wind farm construction

"The Dudgeon offshore wind farm will feature 67 Siemens 6MW wind turbines."

Onshore cable construction works started in March 2015 and the offshore foundation installation, testing and commissioning started in 2016. The monopile foundations were installed using Seaway Heavy Lifting's crane vessel Oleg Strashnov.

The inter array cables, which are equipped with hang-off termination technology, were pulled inside the monopile foundations to connect the turbine generators with the offshore substation.

The export cable was loaded on to a cable installation vessel in Karlskrona, Sweden, and was laid between pre-drilled ducts in the landfall area towards the offshore substation.

Contractors involved

Siemens was awarded the contract for the engineering, supply, commissioning and service of 67 wind turbines for the Dudgeon wind farm. In addition, the company was awarded a turnkey contract in September 2014 to deliver the grid connection for the project.

The contract for the fabrication of the monopile foundations was awarded to Sif Group, while Atkins provided the monopile foundation engineering and management assistance. RG Carter was selected to build the onshore operations and maintenance base, while the installation contract of the wind turbine generators was awarded to A2SEA.

ABB was awarded the engineering, procurement and construction (EPC) contract for the submarine export cables. Seaway Heavy Lifting was awarded the monopole foundations and offshore substation installation contract. A five-year service operation vessel contract was awarded to Esvagt.

Visser & Smit Marine Contracting (VSMC) was awarded the engineering, procurement, construction and installation (EPCI) contract for the export and inter-array cables. The inter-array cables will be designed and supplied by JDR.

Carillion is responsible for the underground cable construction and installation.

NRI Energy Technology