If the word "wind farm" calls to mind ranks of white windmills bestriding green fields, think again. Think rigs and ships and vast platforms out at sea.

Offshore wind energy could be the North Sea oil and gas of the 21st century, a world-class industry supporting upwards of 50,000 jobs by 2024 and generating a higher proportion of the nation's power than a revived nuclear industry - at least, this is the view of scientists at The Open University's Energy and Environment Research Unit (EERU).

They also envisage the UK playing a pivotal role in a "Su- pergrid" linking huge offshore wind farms in the UK, Germany, Denmark and eventually Southern Europe, which will be a common power source for EU member states and help even out the peaks and troughs in supply caused by varying wind speeds.

"The United Kingdom is the Saudi Arabia of wind energy," says Godfrey Boyle, director of the EERU, one of the country's leading centres for research into renewable sources of energy. "The offshore resource is huge, like offshore oil and gas was. We should be going for it with enthusiasm, rather than timidly as we are now."

EERU's report, backed by detailed figures, was submitted as evidence to the Department of Trade and Industry (DTI) Energy Review published in July. It makes the case for public-private partnership with pump-priming by Government to create the infrastructure and investment necessary for a thriving offshore wind industry.

And, like other advocates of renewable energy sources, Boyle is also concerned that unless a strong case is made, the current emphasis on the development of the nuclear industry may divert much- needed resources and investment away from renewables.

Offshore wind could, in theory, be part of an energy mix that includes the revived nuclear industry projected by the Energy Review. According to EERU's calculations, a programme of wind turbine installation, building from 90 turbines a year in 2006 to 400 a year in 2015, with a progressive increase in turbine size as well, would mean that by 2024, offshore wind farms could be producing some 94 terawatt-hours of electricity annually, just over 26 per cent of current annual UK electricity demand, and saving some 5.7 per cent of the nation's current annual carbon emissions.

By comparison, a major nuclear expansion along the lines envisaged by the Government would generate some 82 T Wh a year, 23 per cent of current demand and a saving of some five percent of emissions. The Government's own figures suggest that the generating costs of offshore wind power, including an allowance for investment costs and the cost of additional backup supplies for use when the wind isn't blowing, would be slightly cheaper than those of nuclear power.

A target 400 new offshore wind turbines a year - equivalent to some 2,000 megawatts generating power per annum -is not a particularly ambitious one. In fact 2,000 megawatts a year is the average rate at which wind turbines have been installed on land in Germany over the last few years, and slightly less than the rate of installation in the US in 2005.

And offshore, there is no lack of room for wind turbines, says the EERU report. "The programme we envisage would involve the installation in 18 years of around 6,000 offshore turbines, ranging in size from the current three-megawatt to the five-megawatt size expected after 2012. These could be located in, say, 30 arrays of 200 turbines each. There is no shortage of space for such arrays in the UK's extensive surrounding seas, allowing room for shipping lanes, fishing, defence radar exclusion zones and other uses."

Some 50,000 people are employed in the German wind energy industry, so a similar installation rate for the UK should generate a similar number of jobs, in manufacture, assembly, delivery, installation, connection and servicing of offshore wind farms. The creation of a wind industry would help ensure continuing employment in the UK offshore sector, as reserves of oil and natural gas decline.

The Government's current offshore wind strategy is relatively modest. There are three UK offshore wind farms, with a total capacity of 210 megawatts, and a further 190 megawatts capacity is expected by the end of 2006. The DTI's plans involve an expansion of 1,000 megawatts over the next few years, in round one of a two-part strategy. Round two envisages a further 15 additional offshore wind farms, bringing the total capacity up to some 7,200 megawatts, far short of EERU targets.

But Boyle finds encouragement in sections of the Energy Review, such as the provision to increase the Renewables Obligation - the amount electricity companies have to draw from renewable sources - up to 20 per cent by 2020. More detail is needed, which he is hoping to find in the next step in the development of the Government's energy strategy, a White Paper expected around the end of the year.

"The Government talks of 'banding'- introducing higher levels of support for offshore wind, tidal and wave power, but we need to know what these are.

"I would like to see increased support for offshore wind in the Renewables Obligation, at least for a transitional period. The industry needs to invest in large installation equipment and new electrical transmission links. When it is over that investment hump, the costs will start coming down."

Incentives should favour offshore wind above onshore because the onshore industry is better established and needs less support, he says. Onshore wind is already quite attractive economically because the costs of installation are not so high.

Building the new electrical infrastructure needed to connect offshore wind farms and other marine technologies, such as wave and tidal power, to the national grid will also be expensive. The EERU argues that this can be funded by the creation of a public-private partnership.

But however strong the case for offshore wind, its proponents fear it may not be taken seriously. "In the past nuclear has been the cuckoo in the nest," says Boyle. "It has crowded out other energy sources. In an ideal world, it would be possible for investment to include nuclear and renewables, energy saving, carbon capture and storage and so on.

"But in the non-ideal world in which we live, there is a tendency for investors to go for what Government favours, and the impression has been given that Government favours nuclear. Things may be different this time, but we will have to wait and see."

More details of the EERU evidence are in Godfrey Boyle's article Offshore Wind: the Enormous Potential in the July-August issue of Refocus, published by Elsevier Advanced Technology, Oxford. The Energy Review is available at www.dti.gov.uk/energy/review/

The UK is the Saudi Arabia of wind energy. The offshore resource is huge'