It has been said that wind turbines , once you consider all the greenhouse gas (GHG) emissions associated with their manufacture as well as the site construction process and operations, do not actually reduce carbon emissions as much as is claimed by wind proponents.
Detailed analysis has been done on the GHG emissions of different generators over their entire lifetimes and considering ALL emissions - in manufacturing, construction and operation. This is known as 'Life Cycle Carbon Analysis'.
One of the more comprehensive of these studies, summarised in the chart above, was carried out by the Intergovernmental Panel on Climate Change. This demonstrates that wind turbines, over their entire life-cycle and including manufacturing, construction and operations, emit 80 times less GHGs than a coal-fired power station and 40 times less than a natural gas fired power station.