Work began at the site, 20km off the Kent and Essex coasts, in January 2012 and there are currently 55 turbines connected and exporting power to the national grid.
The windfarm, which began generating electricity in October this year, is expected to be fully operational by spring 2013.
If the second phase is approved, an additional 240MW of generating cap city will be added to the 245km2 site.
Dong Energy owns 50 per cent of the project, Eon 30 per cent, and Masdar 20 per cent.