DONG Energy, Masdar and E.ON have been given the go-ahead to build the world’s largest offshore wind farm, the London Array, in the Thames Estuary.

The partners have each agreed to invest a total of €2.2bn (£2bn) to build the first 630MW phase of the project. Once complete, the London Array will be the world’s first 1GW offshore wind farm and is expected to supply enough electricity to power around 750,000 homes.

Anders Eldrup, chief executive of DONG Energy, said: ‘Following the 2 Renewables Obligation Certificate (ROC) announcement, and our subsequent decision to build the Walney projects, I’m thrilled that we also have the final investment decision on the London Array project. The decision to build the London Array offshore wind farm is a very significant cornerstone in DONG Energy’s strategy to increase the proportion of electricity generated from renewable energy sources. DONG Energy has built approximately half of all offshore wind farms in operation in the world today.

The London Array will be built in two phases on a 90 square mile site, around 12 miles off the coasts of Kent and Essex. The first phase, which will involve the deployment of 175 turbines, is scheduled for completion in 2012. The second phase will add enough capacity to bring the total to 1,000MW. Offshore work is due to start in early 2011.

The announcement follows the government’s pledge to increase offshore wind power and implement plans to create a low-carbon economy. According to project leaders, the London Array will displace the emission of 1.9m tonnes of CO2 every year.

Gordon Brown said: ‘The London Array is a flagship project in our drive to cut emissions by 80 per cent by 2050 and meet future energy needs. The UK is a world leader in offshore wind farms, creating jobs and prosperity for the economy. That’s why we have increased our support for this technology as we move towards a low-carbon future. E.ON, DONG Energy and Masdar are to be congratulated for their work on the London Array.’

Energy secretary, Ed Miliband, added: ‘This is another green light for green energy. It’s a vote of confidence in the support the government has put into backing renewable energy. The UK is already the world’s leading offshore wind power and this multi-billion pound project will help keep us there, cut our carbon emissions and contribute to secure energy supplies.’