Under Section 36 of the Electricity Act 1989, the Secretary of State for Trade and Industry makes decisions on proposals in England and Wales for onshore wind farms greater than 50MW. The five such applications determined between March 2001 and March 2006 took an average of three years.
Applications for onshore wind farms of 50MW or less are decided in England and Wales by local planning authorities under the Town and Country Planning Act 1990. Figures from the British Wind Energy Association show that decisions made between January 2005 and September 2006 have taken an average of 15 months in England and 23 months in Wales.
This is dependent on the size of the wind farm. Wind farms are typically designed to operate for more than 20 years. A recent life cycle assessment provided in support of a 60 megawatt wind farm proposal indicates that it would pay back the carbon dioxide emissions due to the development, construction, operation and decommissioning in approximately seven months.