15 August 2011 Last updated at 10:42 ET

Three steps to build a wind farm

The turbines pictured above are now part of the Ormonde wind farm, built by Swedish-based energy firm Vattenfall. The site, located off

the Cumbrian coast, has 30 of the five-megawatt turbines in total and should be able to power around 100,000 homes.

Is wind power the answer?

By 2020 the government hopes that 15% of the UK's energy will come from renewable sources with wind energy making a key

contribution.

But although the UK has access to some of the world's best resources for producing wind energy, offshore wind farms remain an

expensive way of producing electricity.

Professor Dieter Helm, an economist from the University of Oxford, told the BBC he doubted a large expansion in offshore wind power was

affordable. He said: "Offshore wind is one of the very few things that makes nuclear power look cheap."

The graphic above refers to energy projects started in 2009. As time passes costs are expected to drop, the government hopes that offshore

wind can reach 100/MWh by 2020.

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