Offshore wind farm London Array, UK

Published:  29 July, 2016

The world’s largest offshore wind farm 
London Array is the largest offshore wind farm currently in existence (as of 2014). Our contribution to this mega-project was design, fabrication and installation of the foundations, as well as transport and installation of the turbines. The 175 wind power generators, with a 630 MW capacity, are situated in the Thames estuary, roughly 20 km off the coast of Kent and Essex. The project is divided into two phases and will, after completion of the second phase, provide electricity to 750,000 households.

A wind farm of colossal proportions
The 177 monopiles are up to 60 m in length and have diameters ranging between 4.7 and 5.7 m. With the longest weighing roughly 650 t, they were driven up to 25 m into the seabed. The transition pieces, connecting the foundation and the wind power system, each weigh 350 t and are 27 m long. A total of 100,000 t of steel was used for the foundations. The monopiles were manufactured in Rostock, while the transition pieces were constructed in Denmark. Once production was complete, the monopiles and transition pieces were transported on barges to the port of Harwich in Great Britain, where they were loaded onto special installation ships and taken to the project area. 

The project at a glance

Client:
London Array Ltd. (joint venture between Dong Energy A/S, E.ON UK LTD., Masdar Ltd)

Location: 
UK, approx. 20 km off the coast of Kent and Essex, in the Thames estuary

Construction period: 
2009 - 2012

Partner: 
50:50 joint venture with the Danish company Per Aarsleff A/S

Foundation type: 
Monopile 

Services: 
"Design and Build", installation of the 177 monopile foundations and transition pieces, transport and logistics for the installation of 175 Siemens 3.6 WTGs 

Water depth: 
0 - 25 m

Foundation dimensions:
Length: max. 60 m, ø: 4.7 – 5.7 m, weight: max. 650 t 

Installed capacity: 
600 MW, 3.6 MW/turbine