The world's largest offshore wind farm is to come up in Britain. It will involve as many as 341 turbines.
Comprising of about 90 square miles, it will be built 12 miles off the coasts of Kent and Essex to the east of London in the Thames Estuary.
The wind farm will be built in two phases. The first phase will consist of 175 turbines. The second phase will add enough capacity to bring the total to 1,000MW, with up to 341 turbines.
Dong Energy is based in Denmark, Masdar is an Abu Dhabi company while E.ON is German-owned.
Power giant E.ON said the first phase of the London Array project will start later this year and it could be generating power in time for the 2012 Olympics.
The project had been on a knife-edge, but increased support for renewable energy announced in the recent Budget led to the eventual green signal.
E.ON and its partners Dong Energy and Masdar said they will invest £2billion in building the first 630 megawatt phase of wind farm in the Thames Estuary.
Onshore work is now due to start in the summer, with offshore work due to begin in early 2011. Once complete, the scheme will be the world's largest, and the first 1 gigawatt offshore wind farm.
The project will supply enough power for around 750,000 homes - a quarter of all those in Greater London - and displace the emission of 1.9 million tonnes of CO2 every year, Daily Mail reported.
John Sauven, executive director of Greenpeace, said: 'Cutting-edge projects like the London Array will help generate clean, secure energy, and they'll generate thousands of British jobs.
'The UK has the best renewable energy resources in Europe, and the know-how to harvest it. The London Array should be the start of a major expansion of offshore wind to help power Britain.
'The Government now needs to remove the hurdles that have stopped the faster development of the wind industry.'
Friends of the Earth executive director Andy Atkins was equally enthusiastic. He said: 'It's fantastic news that the UK will be home to the world's largest offshore wind farm.
'London Array will cut UK emissions, reduce our dependency on fossil fuels and create hundreds of new green jobs.
'The UK has the best offshore wind resource in Europe. Ministers must ensure that more projects like this are developed so that Britain reaps the huge employment, business and environmental benefits of clean, green energy.
'This must include a new super-grid to ensure we get maximum benefit from offshore energy, and greater efforts to make sure that turbines are built in Britain - not imported from abroad.'
The firms behind the project said in a statement: 'The partners are satisfied that the project is now financially viable and are now keen to push ahead with construction and to produce the first renewable power in 2012.'
E.ON chief executive Dr Wulf Bernotat said: 'I'm delighted that work can now get under way on the world's largest offshore wind farm.
'The start of London Array will mark a key milestone in our roadmap as we continue with our ambitious strategy to take renewables to an industrial level.
'With this pioneering scheme, we see a significant increase in scale for offshore wind and also for E.ON as we aim to become the world's largest offshore wind farm developer.
'Today's announcement is proof that, if all interested parties work together, renewable power can be taken to its next level and so make a real difference to the fight against climate change.'
Prime Minister 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.'
Energy and Climate Change Secretary Ed Miliband said: '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.'
Hundreds of jobs are expected to be created in the construction phase of the project.