Said to be the only wind farm to be built offshore in the UK waters this year, the project is being developed on the southern side of the Outer Thames Estuary.
Featuring 15 wind turbines, the power plant covers an area of approximately 7.8km², and is expected to commence production later this year.
Vattenfall UK country manager Piers Guy said: "It’s important the UK pipeline keeps delivering – and Kentish Flats Extension does that in a modest way – so that British suppliers can maintain a foothold in the sector and help capture the significant economic opportunities that go with it."
The extension project will produce up to 173,000MWh of clean electricity a year, which can serve around 35,000 UK households.
Vattenfall Kentish Flats Extension project director Matthew Green said: "A number of large vessels will be offshore Herne Bay and Whitstable this summer as we add 15 turbines to the existing 30 at Kentish Flats."
In May 2010, Vattenfall was selected by the Crown Estate to extend the 30-turbine Kentish Flats wind farm, located around 8.5 to 13km north of Herne Bay and Whitstable in Kent.
