UK using wind turbines to harvest
more green power

Sea change: Artist's impression of an ocean wind farm. Courtesy British Wind Energy Association

Wind power is set to make an important contribution to the drive in Britain to produce 10 percent of its electricity from renewable sources by 2010. The number of onshore wind farms in the United Kingdom is growing and there are imaginative proposals in the pipeline to build turbines offshore around the country's extensive coastline.

Surveys are now under way to enable the builders to overcome significant construction and operational problems in deep water, hostile conditions and gale-force waves and winds that, obviously, are not ideal for turbines. There is enormous energy potential and developers will benefit substantially from procedures and techniques already developed for other UK offshore activities, including the North Sea oilfields.

Most of the wind farms will be at least five kilometres (about three miles) from land. Experts say that an area of sea roughly the size of London is all that would be needed to generate 10 percent of the UK's electricity needs. The first offshore turbines were expected to begin producing electricity in 2000 and research is also underway on designs to have turbines set on barges floating off the coast.

Britain has nearly 800 operational turbines on 45 wind farms and they produce 350 megawatts (MW) of electricity. The target is to have 5,000 much larger turbines - an average of 1.2 MW in size - shared between onshore and offshore locations with the hope that they can produce between a third and a half of the 10 percent electricity target.

One big breakthrough was cost; wind power is now competitive with electricity from fossil fuel and cheaper than that from nuclear power. Modern wind turbines have two or three bladed rotors around 45 metres in diameter, supported by tubular steel towers rising to 40 metres. When the wind blows, the blades turn at a constant speed of about 30 revolutions a minute, driving a gearbox and a generator that feeds its electrical output to the electricity grid.

A typical well-sited wind farm of about thirty 600-kilowattt turbines has an output sufficient to meet the electricity needs of some 15,000 homes. This alone would offset the emission of thousands of tonnes of carbon dioxide a year. Experts believe that wind farms could eventually provide up to 20 percent of UK electricity needs.

There has been some resistance to the idea of wind turbines, with environmental and countryside groups expressing their reservations. In sensitive areas just one or two turbines can be erected to serve a community, so that people can identify with the machines producing the power they personally use, say protagonists.

Land right up to the turbine can still be used for agricultural purposes. Offshore, one proposal is a project costing 35 million pounds sterling to build 25 turbines, each of 1.5 MW capacity, off the coast of eastern England.

Prime Minister Tony Blair has said that the UK is committed to putting the environment at the heart of all decision making. Meeting the 10 percent target of electricity from renewable sources would lead to a reduction of five million tonnes in UK carbon emissions, making a valuable contribution to climate-change strategy. And the government is now requiring the country's electricity suppliers to generate a proportion of their output from non-fossil fuel.

At a recent conference, UK Environment Minister Michael Meacher emphasized the UK's commitment to renewable energy and its determination to see a 20 percent reduction in carbon dioxide gases by 2010. He said: "Climate change poses a serious threat to mankind - it will not go away and the 'do nothing' option is not, in fact, an option. The UK has to make use of its geography - we have potentially 40 percent of the European Union's wind resource."

According to a recent report commissioned by Greenpeace, the European Wind Energy Association and the international Forum for Energy and Development, wind power could meet some 10 percent of world needs by 2020, cutting carbon dioxide emissions by more than 10 billion tonnes.

One unexpected benefit in the UK is that its first commercial wind farm ­ which began operating in 1991 ­ now attracts 35,000 tourists a year.

Details: British Wind Energy Association, 26 Spring Street, London, United Kingdom, W2 1JA.

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