IT IS being billed as the next North Sea boom. This week the tentative go-ahead was given for the construction of up to 2000 giant turbines off the coast of Scotland, with big projects planned for the Firth of Forth off Edinburgh and the Moray Firth off Inverness. These first offshore wind farms in Scotland are not the half of it, however.

In the spring, we will get the first indications of where new projects for another 5000 wind turbines are to be sited elsewhere around UK shores, with the seabeds of the Thames Estuary, round East Anglia and up to the Humber likely to feature strongly.

The number of firms queuing up to cash in indicates that our energy firms have got a whiff of the sort of a bonanza that made fortunes for those in the North Sea oil boom of 1970s and 1980s, as offshore windpower will receive lucrative subsidies, allowing operators to charge far more than land-based conventional power plants for their generated electricity.

This year will be a watershed, as it were, for sea-based wind farms. If wind is the future - which the Department of Energy and Climate Change has said it is - then offshore is where it will happen. Offshore wind farms are more expensive to construct than those on land, but they can a) produce far much more power and b) are much more likely to get planning permits.

But the step change in the industry that is being considered is almost inconceivably huge. The Energy Department's plan indicates that it wants a total of 33,000MW of electricity to be generated by offshore wind by 2020. That would equate to about 40% of the nation's installed generating capacity, powered by a staggering 8000 turbines in the next 11 years.

They had better get a move on, as thus far the turbines of the wind industry have ground slowly. Since the first offshore licences were granted in 2001, almost 30 projects have been approved. However, in that eight years, just six have gone into operation following the commissioning of North Hoyle off North Wales in 2003.

These installed turbines are producing a maximum of 550 megawatts - less than 1% of the UK's daily needs, barely enough electricity to power a provincial town. Ed Miliband has made several visionary statements since he became Secretary of State for Energy and Climate Change last year - witness a potential £20 billion investment on the untried economics and mechanics of a huge tidal-driven barrage in the Severn estuary.

Miliband's hopes for the take-up of offshore wind, however, stretch credibility and even arch-supporters such as Ian Marchant of Scottish and Southern Energy's Airtricity wind operation euphemistically call the targets "ambitious".

Speak to industry executives, and they will indicate that many of the projects already permitted - and especially the ambitious ones such as London Array in the Thames to power a quarter of the capital's homes - are in abeyance, with construction dates some years in the future or not even specified.

Several questions remain for Miliband to answer over how we get from here to where he wants to be. Who is going to build all the actual turbines when the giant manufacturers of the world are already at full stretch and getting better offers to ship their products to the US and China? If we could source 8000 turbines, where would we get all the personnel and specialist vessels needed to instal them?

Will the National Grid have the capability and the raw materials to connect these wind farms miles out to sea? Where will all the investment come from during the biggest financial crisis in 80 years? Are the big players in the UK offshore market - Centrica, E.ON, RWE npower, Scottish Power, Scottish and Southern Energy - truly committed when they can see better economics and certainties for their investments in the £40 billion plans to build at least six new major UK nuclear plants?

And when will the Government finally loudly confess - as it has already done quietly in its energy consultation papers - that the costs of building offshore wind will ultimately be borne by the consumer, with rises of about 25% in domestic energy bills and even more for industry?

This next "North Sea boom" may just become a blowout.

THE SEVEN WONDERS...

• Our coastlines are among the windiest in the world
• Large areas of shallow waters off UK shores
• Incentives in place to build wind farms
• UK is running short of energy resources
• Wind is an alternative to increasingly expensive fuel materials
• Turbine technology is improving wind farm efficiency
• Will help UK meet carbon emission and climate change target

...AND THE SEVEN DEADLY SINS

• Wind does not always blow, leading to shortages
• Turbines are an environmental and aesthetic blight
• Funding is by rising domestic and industrial energy bills
• Thousands of turbines needed to provide meaningful output
• Maintenance and obsolescence costs are high
• Construction/connection costlier than for normal power plants
• Government targets by 2020 are not credible or achievable