The UK Planning Inspectorate has until 12 July to decide whether to accept it. Atlantic Array is planned for a site in the Bristol Channel, off the Devon and south Wales coasts.
RWE npower renewables has made a series of revisions to its project plans for Atlantic Array, with the latest reducing it from 1.5GW to 1.2GW.
Last year, RWE originally envisaged installing 417 turbines in the Bristol Channel. However in March, it said this had been capped at 278 following environmental studies. At the time, it hoped to reach the 1.5GW through the use of larger turbines.
The latest changes follow analysis of the consultation undertaken in 2011, as well as the results of environmental and engineering studies.
Scaling down the project will reduce its visual and seascape effects, as well as the potential for underwater disturbance during construction. Commercial fisheries, birds, navigation and the ecology of the seabed will also benefit from the refinements.