TG Fielding says: "Wind is one of the most extensive ways of reducing carbon emission" (Letters, August 4).

While every wind farm application states the number of kg of CO2 which can potentially be saved, there is no evidence that fossil-fuelled power stations reduce output to accommodate wind generation.

Wind farms, which do not produce anything which can remotely be called an electricity supply, need constant power station back-up to ensure secure, dependable electricity.

A power station is not like a stand-by back-up diesel generator which is on or off at the press of a button. The widely held belief that wind farms reduce our dependency on power stations and reduce carbon emissions is false.

AR Nelson,

5 Scarletmuir, Lanark.