The subsidy system supporting wind farms in the UK is one of the most expensive in Europe, according to research by the European Commission. Only Italy’s system, which is of a similar style to the UK’s “renewables obligation” or RO, gives renewable electricity companies a greater expected profit.

The subsidies come not from the taxpayer but the electricity consumer, adding £1bn a year to electricity bills by 2010, rising to £3bn by 2020. But although the subsidies are intended to increase the amount of electricity produced from renewable sources – of which wind is one of the cheapest and most mature – fewer new wind farms are being built, owing to planning restrictions.