All 116 of the turbines at the Rampion Offshore Wind Farm in Sussex are now able to generate electricity and are delivering power to the grid.
A spokesman for E.ON said the commissioning of the wind turbines marked 'a significant milestone in the project', which commenced offshore construction in early 2016.
It brings the scheme up to its maximum generating capacity of 400MW, which will provide enough electricity to supply almost 347,000 homes a year - equivalent to around half the homes in Sussex, the spokesman said.
Work will continue both on and offshore over the coming months to prepare the site for full operation later this year, added the spokesman.
Matthew Swanwick, project director for the Rampion Offshore Wind Farm, said: “We’re delighted to have now reached the point where all of the wind turbines are up and running and contributing yet more clean power, adding to the UK’s growing renewables fleet and its ability to help meet the UK’s energy needs.
“We still have a number of activities to complete, for example at the onshore and offshore substations and landfall, so people will continue to still see ongoing activities offshore and onshore over the coming months.
"Full reinstatement of the onshore cable route back to its former condition is another top priority for us this year.”
The wind farm was built 13km off the Sussex coast by E.ON, Canadian energy infrastructure company Enbridge and a consortium comprising of the Green Investment Group, Macquarie European Infrastructure Fund 5 and the Universities Superannuation Scheme.
The project is due to be completed and fully operational later this year.
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