Final assembly of the first phase of the London Array wind farm

by business editor Trevor Sturgess

The first phase of the world's largest offshore wind farm off the Kent coast is complete with the installation of the 175th turbine.

London Array, the £2billion project in the Thames Estuary, off Ramsgate, has been supplying power to the National Grid since October - but energy levels should rise after the latest milestone. Turbine installation began in January 2012 .

With all turbines in place and 55 connected and supplying power to the National Grid, the wind farm is on track to be fully operational by next spring.

The project has involved 84 foundations, 175 wind turbines, 178 array cables and three export cables to the onshore sub-station at Cleve Hill, Graveney.

London Array, a consortium of DONG Energy, E.ON and Masdar, is now focusing on the commissioning and testing of the remaining turbines before the project is handed over to an operations and maintenance team, largely based in Ramsgate. The project has injected an estimated £15million into the east Kent economy.

The first phase has a combined capacity of 630MW - enough power for 470,000 homes. A second phase, for which planning permission is being sought, would boost the total to 870MW, adding up to 65 extra turbines. The area is less than originally envisaged to protect the wintering grounds of rare red-throated divers from northern Europe.

Benj Sykes, head of DONG Energy's UK wind business, said: "The London Array will soon be the largest operational offshore wind farm in the world - building offshore wind farms of this size and larger in the future allows us to harvest the advantages of scale and is an important element of our strategy to drive down the cost of energy."

Tony Cocker, E.ON chief executive officer, added that it was a significant milestone for London Array and the UK.

"I look forward to seeing London Array's contribution to the UK’s low carbon energy mix for many years to come."

Dr Sultan Ahmed Al Jaber, Masdar CEO, said: "This milestone brings us a step closer to showcasing the economic, social and environmental benefits of clean energy."