Harvesting the power of wind

Photo: London Array

At the widest point of the Greater Thames estuary, between the sandbanks of Kentish Knock and Long Sand, lies the London Array - the largest offshore wind farm in the world. 

Covering an area of 100 km2, the London Array comprises 175 massive turbines and two substations laid out in neat rows like a vast plantation of mechanical palm trees.

It produces up to 630 megawatts of electricity - enough power for more than half a million homes a year.

This vast wind farm symbolises the world's increasing focus on renewable energy sources. In the UK alone, the goal is to provide 15 percent of Britain’s energy from renewable sources by 2020.

Keeping risks at a minimum

According to COWI Senior Market Director Jan Rønberg, there is a rapidly growing demand for offshore wind. At the same time, there is a transition taking place within the offshore wind industry.  
"The industry is in a transition from being highly subsidised to an industry competing purely on market prices. Suppliers must provide innovative and high-quality solutions, while having the necessary control measures in place to keep the risks at a minimum," he says.

Great variations in the sea bed were among the major challenges when designing London Array. market director jan rønberg tells the story.

Suppliers must provide innovative and high quality solutions, while having the necessary control measures in place to keep the risks at a minimum.
Jan Rønberg Market Director, COWI

The need for high-quality, innovative solutions also applied to the monopiles supporting the wind turbines in the London Array.

These gigantic steel structures are up to 100 metres tall and are made of cylindrical steel tubes, which are driven into the seabed.

COWI carried out the detailed design of the steel foundations, which are 5.7 metres wide and weigh as much as 1,000 tonnes in total.

To handle the enormous amount of data sets involved, the COWI team created COPILOD - a complex software platform that incorporates the latest design knowledge, stores all design information and compiles data and drawings.

“The tool makes it possible to achieve a high-quality and fast generation of design drawings and reports. It enables you to execute the design of foundations quickly and make amendments in minutes when otherwise they would take days to perform,” explains Technical Director, Martin Kelm.  

unique monopile design

The varied soil layers put heavy demands on the monopile design. Click on video to know more.

facts About the london array

  • The London Array project was launched in 2001, when a series of environmental studies in the outer Thames Estuary confirmed the area as suitable for a wind farm. 
  • Two years later, in 2003, the Crown Estate gave London Array Ltd a 50-year lease for the site and cable route to shore. 
  • The wind farm is located 20 km off the Kentish coast. Construction of the onshore substation started in July 2009 and the first turbine was installed in 2012.
  • Later in 2012, power was obtained for the first time.
  • Project owners: Ørsted,  E.On, Masdar and La Caisse de dépôt et placement du Québec


North Sea 


Aarsleff | Bilfinger
Berger Joint Venture


  • Structural design
  • Geotechnical design
  • Hydraulic calculations
  • FEM analysis

Get in contact

Jan Rønberg

Jan Rønberg
Senior Market Director
Marine and Foundation Engineering, Denmark

Tel: +45 56401561