The world’s largest offshore wind farm has been given the go-ahead to be built in British waters.

Energy Secretary Ed Davey has granted planning permission for the ambitious scheme – which could cost bill payers more than £10.5billion in green subsidies.

The plan is for 400 turbines to be erected in a giant grid structure 80 miles off the Yorkshire coast, covering 430sq miles in the area known as Dogger Bank.

Growth: The new windfarm off the Yorkshire coast would dwarf this one, Walney, off Cumbria

The plan is for 400 turbines to be erected in a giant grid structure 80 miles off the Yorkshire coast, covering 430sq miles in the area known as Dogger Bank

The Creyke Beck wind farms would be more than twice the size of the London Array, currently the world’s biggest offshore wind farm.

The turbines are expected to power 1.8million homes – about 2.5 per cent of Britain’s entire electricity requirement.

The building costs of the project are estimated at up to £8billion, which will be paid by Forewind, an international consortium of energy companies SSE, RWE, Statkraft and Statoil.

But if the plan is approved for inclusion in the Government’s subsidy scheme, Contracts for Difference, the firms could expect to make their money back within a decade because it would guarantee them a fixed price for the electricity they produce.

The decision on inclusion in the Contracts for Difference will be made by 2017 by whoever is Energy Secretary at the time, and then Forewind will decide whether to begin construction or not.

If the consortium is granted access to the programme, which is funded through a green subsidy on energy bills, it can expect to receive an estimated £700million a year – or £10.5billion over the 15 years of guaranteed funding.

Dr John Constable, director of Renewable Energy Foundation, which calculated the figures, said the size of the project is so big that it could alter the shape of the British economy.

He said: ‘The Creyke Beck offshore wind farm would receive about £700million a year, and all drawn from consumer bills.

'Additional energy costs on this scale will affect the course of British economic history, and not for the better. The last time public subsidies on this scale were directed towards a single industry it was called British Leyland. Arguably, not a good omen.’

And the scheme could still grow even bigger, with a decision on a second project, Dogger Bank Teesside, expected in August.

Tarald Gjerde, general manager of Forewind, claimed that Creyke Beck could create up to 4,750 jobs over its 25-year lifespan.

Liberal Democrat Mr Davey said: ‘Making the most of Britain’s homegrown energy is creating jobs and businesses in the UK, getting the best deal for consumers and reducing our reliance on foreign imports. Wind power is vital to this plan, with £14.5billion invested since 2010 into an industry which supports 35,400 jobs.’

Energy Secretary Ed Davey (pictured) has granted planning permission for the ambitious scheme – which could cost bill payers more than £10.5billion in green subsidies

The Government is keen to expand the number of offshore wind farms because they do not attract the same local opposition as onshore projects.

However, the offshore alternatives come at a price.

Every wind turbine built at sea costs bill payers an extra £300,000 a year in public subsidies, according to the Royal Academy of Engineering.

The Committee on Climate Change has estimated that green subsidies made up £45 of the average £1,140 dual gas and electricity bill in 2013. This will rise to £100 by 2020, and £175 by 2030, by which time the total average bill will be £1,305.

There are 1,200 offshore wind turbines in British waters today. The Government wants 3,000 by 2020.