The move takes the UK's total wind capacity to 5GW and follows on from last month's completion of the 172MW Gunfleet Sands wind farm in the North Sea.
However, despite the impressive figure there have been misgivings in the UK press about the state of the UK's wind industry.
National news channel Channel 4 news reported that only 20% of the construction jobs for the Thanet farm went to the UK.
The Guardian newspaper pointed out the 20% was comparatively good compared to other UK offshore projects. The paper said: "The 20% figure is better than the 10% reported by E.ON and its partners on the London Array scheme, which will open in 2011, but is still an embarrassment to government."
While RenewableUK, the national body for Britain's wind industry, is warning 50,000 jobs could be at risk if manufacturers base their offshore wind operations outside the UK.
The wind industry itself was quick to hail the 5GW breakthrough. Vestas chief executive Ditlev Engel said: "Vestas is incredibly proud of its successful partnership with Vattenfall in building Thanet, the world's largest operational offshore wind farm. This is yet another key landmark in the UK's bid to meet its energy and climate goals, and create local UK jobs.
"The UK's 5GW milestone is testament to industry achievement. Vestas looks forward to playing a major role in the UK government's future plans for on and offshore wind, and reducing the cost of energy."
Christina Grumstrup Sørensen, senior vice president of Dong Energy Renewables said: Dong Energy is already, together with partners, building the world's largest offshore wind farm the London Array. We have invested £ 2.6 bn. in offshore wind projects, and with our 20 years experience in building offshore wind power we are contributing to Britain's renewable energy future."