Professor Dieter Helm
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Wind farms: 'The question is, who will pay?'

15 August 2011 Last updated at 19:14 BST

This week, BBC News is taking an in-depth look at offshore wind farms, and the challenges, costs and construction of these sea giants.

Here, science correspondent David Shukman talks to Professor Dieter Helm, an economist from the University of Oxford, who believes that while the UK government should invest in more green power generation, offshore wind farms are far too expensive.