The ambitious scheme, hailed by environmental campaigners as a historic commitment towards harnessing green energy sources, will see a string of wind farms built around the country's long and often blustery coastline.

Energy from the planned new developments will eventually be enough to power more than 3.5 million households, Trade and Industry Secretary Patricia Hewitt told a news conference in London.

"This announcement is good for the environment, for Britain's energy needs and for jobs," she pledged.

Farms, which could contain up to 300 massive turbines at a time, will be built around five miles (eight kilometres) off the coasts of northwest England and north Wales, East Anglia in eastern England and the estuary of the River Thames to the southeast of London.

The sites would be too distant to be clearly visible from the shore, and environmental factors such as bird breeding grounds would be taken into account, Hewitt said.

The first project, 30 turbines being built off North Wales, is expected to start producing power later this year.

Tenders for new wind farms must be submitted by firms within three months, with leases then awarded for new projects.

Environmental campaign group Greenpeace hailed the move as a landmark.

"For 30 years Greenpeace has opposed the pollution of our oceans but can today fully support this massive commitment to harness wind power at sea," said spokesman Rob Gueterbock.

"Global warming poses a unique threat to our planet, but the government is now demonstrating the ambition needed to defeat it.

"We have the most abundant energy resource in Europe and could soon have an industry to match it."

Britain's government has pledged to provide 10 percent of Britain's energy from renewable sources by 2010.

SPACE.WIRE