The world's largest offshore wind farm, which cost more than GBP750m to build, is poised to begin generating power off the coast of Kent, south-east England, with 100 turbines producing enough electricity to supply heat and light for some 200,000 homes.

The Thanet facility, which is going through final testing by Vattenfall, its Swedish power company operator, is going on stream as the National Grid revealed that at one stage last week 10 per cent of the U.K.'s electricity came from wind farms.

But industry experts claim that the wider green revolution needed to meet renewable and climate change targets imposed by the European Union is still in danger from proposed spending cuts.

Chris Huhne, the energy and climate change secretary, will open the facility, which is 7.5 miles (12km) off Foreness Point, on 23 September.

The Thanet farm, which will be able to produce 300MW of electricity, will be the biggest offshore facility of its kind until the even larger London Array, which has an eventual goal of 340 turbines, is completed.

It will dwarf the nearby Kentish Flats facility off Whitstable, also run by Vattenfall and using similar Vestas turbines.

Excitement about the potential for wind was heightened last week when the grid put out a statement that over a 24-hour period up to 10 per cent of electricity came from wind and 4 per cent from hydro.

Maria McCaffery, chief executive of RenewableUK, said the figures underscored the contention that wind and renewables were no longer “alternative” but core parts of the power sector.

“We are expecting to see the contribution of electricity from wind gradually increase over the next decade, to around 30 per cent of the UK's total consumption.

This news confirms that not only are the wind farms we have built so far starting to deliver, but that U.K. wind farm yields are the best in Europe, and comparable with established technologies such as hydro,” she said.

The U.K. currently generates only 3 per cent on an annual basis, although last week's figure from the National Grid shows that — on a temporary basis at least — that figure can be much higher. — © Guardian Newspapers Limited, 2010