Businesses were urged last night to cash in on a new green energy building boom off the East Anglian coast after ministers put billions of pounds of windfarm contracts up for grabs.

Businesses were urged last night to cash-in on a new green energy building boom off the East Anglian coast after ministers put billions of pounds of windfarm contracts up for grabs.

Energy minister Lord Hunt gave the go-ahead for construction of a new phase of offshore windfarms - with the aim of generating enough electricity to power 19 million homes.

The minister opened the bidding to businesses for �15bn of contracts just to manufacture and lay cables to connect offshore turbines to the power grid.

But precisely where and how big the new windfarms will be was unclear last night.

A site in the southern North Sea is one of "nine indicative zones for development" around the British coast where companies can bid to exploit wind power - but it has yet to be decided if all or only part of the site will be used.

Lord Hunt's announcement came as the developers behind 88-turbine Sheringham Shoal in The Wash signed a deal with the Wells Harbour Commissioners to use the town as the windfarm's operational base "for up to 50 years".

The Sheringham Shoal - approved under an earlier round of wind power contracts - carries the promise of about 40 new jobs in Wells and has the potential to turn the town into a hub for the green energy industry.

Further around the coast, Lowestoft has also been picked as the operational centre for the world's biggest offshore windfarm, called Greater Gabbard, off the Suffolk coast.

But industry experts last night pointed out that wind power still only accounts for a small fraction of Britain's power needs.

Of the electricity generated between 5pm on Tuesday and 5pm yesterday, 41pc came from gas-fired power stations, 31pc from coal-fired power stations, 24pc from nuclear power stations and 2.5pc was imported from Europe through the interconnector system with France.

Only 0.3pc of the power generated in those 24 hours came from wind turbines on or offshore.

John Best, chief executive of the East of England Energy Group (Eeegr), said the power generation figures showed the scale of the task if the government was to meet its aim of generating 15pc of the country's energy from renewable sources by 2020.

Ironically, Lord Hunt's announcement yesterday suggested that offshore wind "has the potential to meet more than a quarter of the UK's electricity needs".

Mr Best said: "Announcements like these are to be welcomed, but we need to continue to move from the rhetoric of announcement to the reality of delivery."

He added that there was a "generation who don't understand generation" and called for a more informed debate about energy issues.

Caroline Williams, chief executive of Norfolk Chamber of Commerce, said that the region's credentials in the oil and gas industry left it well-placed to benefit from the promised expansion of green energy.

"Norfolk business needs to grab hold of the opportunities which the announcement by Lord Hunt could bring," she said.

"We need to demonstrate our expertise and the drive to ensure that Norfolk benefits from the new jobs and annual revenue which will follow.

"The Eastern region does have a strong energy supply chain and Norfolk will need to be assertive to ensure as much work as possible is placed with our businesses."

Chris Starkie, chief executive of economic development partnership Shaping Norfolk's Future, said: "The announcement is good in theory, but it seems like a very ambitious target. What we would like to see now is real government support to help build the supply chain so design and construction of the turbines can take place in the UK.

"In Norfolk, the Hethel Engineering Centre is leading the development of an east of England wind energy supply group to pool expertise in wind turbine design and construction, and it is initiatives like this that the government must support if it is serious about offshore wind."

Energy and climate change minister Lord Hunt said wind power presented a "huge opportunity" for the UK industry.

"We're already the world's number one offshore wind power. With the right support, we can grow the industry even further, supporting tens of thousands of high-value, green manufacturing jobs."

Maria McCaffery, chief executive of the British Wind Energy Association, said the "extremely ambitious" target could result in every home in the UK being powered by offshore windfarms by 2020 - if the right infrastructure was put in place.

Dr Doug Parr, Greenpeace chief scientist, said: "Offshore windfarms must be a key part of the UK's future energy supply.

"And they won't just generate electricity, they'll also generate thousands of British jobs and help tackle energy security.

"But, if Britain is to get all the benefits that offshore wind will provide, the government must do more to support the industry."