All 175 turbines at what is believed to be the world’s largest operating offshore wind farm are now generating clean electricity.

The 630MW London Array in the Thames Estuary has completed its first phase of the project, with the final turbine (pictured) online on Saturday, 6 April.

With all turbines now exporting power to the National Grid, the wind farm is expected to produce enough electricity to power nearly half a million homes in the UK and cut carbon emissions by more than 900,000 tonnes a year.

Project Director Richard Rigg said: “This is the final major milestone of the construction phase and the culmination of more than two years’ offshore construction work which began in March 2011 with the installation of the first foundation.”

RenewableUK welcomed the announcement and said the project is a “real achievement” for Britain. Chief Executive Maria McCaffery added: “It’s a monumental feat of green engineering… To hold on to the UK’s global lead in offshore wind, it’s vital that we maintain this momentum. We must ensure that the crucial legislation going through Parliament right now – the Energy Bill – sets a rock-solid framework to encourage investment in renewables.”

DONG Energy, E.ON and Masdar own 50%, 30% and 20% stakes in the project. The second phase is expected to consist of wind turbines with a total capacity of 240MW if approved.