Alex Henney sends me a 2012 article from the journal New Power, in which he and Fred Udo examine electricity grids in several countries around the world and assess how the use of wind turbines has affected the carbon intensity of the power generated. Suffice it to say that it's not quite what the environmentalists intended.
What is particularly interesting is that the article prompted a response from DECC, whose ability to misunderstand the arguments presented is something to behold, and the resulting correspondence is appended to the end of the file.