The government has granted permission for the 175-turbine Rampion offshore wind farm.
The farm, which will be 13km off the Sussex coast, is expected to support 750 jobs and bring around £2 billion of investment to the UK’s economy.
The government gave the scheme the green light this morning, with German energy giant Eon set to run the site.
Once built, the wind farm would generate enough electricity to power approximately 450,000 homes.
Energy and Climate Change Secretary Ed Davey said: “We’re driving investment in our energy security, and our plans have made us number one in the world for investment in offshore wind energy.
“This project is great news for Sussex, providing green jobs as well as driving business opportunities right across the country in a sector with a clear roadmap for long-term growth.”
Michael Lewis, chief operating officer, E.ON Renewables, said: "E.ON is delighted to receive development consent for the Rampion Offshore Wind Farm proposal.
"This is a key milestone for the project and we firmly believe Rampion will play an important role in helping to ensure future security of supply and make a significant contribution towards meeting the UK's renewable energy targets."
Chris Tomlinson, development manager for Rampion Wind Farm, added: "The wind farm will not only help generate jobs during both construction and operation, but also provide a boost to the port regeneration at Newhaven and the local economy."
The developer, E.ON Climate and Renewables UK Rampion Offshore Wind Ltd, is expected to start onshore construction for the site in 2015, and estimates power generation will start in 2018 or 2019.
For the wind farm to go ahead the company will need to make a final investment decision on the project, and apply for subsidies.