Niall Stuart, chief executive of Scottish Renewables, said wind turbines will only generate revenues if they can be connected to the grid ("Concern over company's £30m turbine windfall", The Herald, March 27).

The generation of public revenues is the raison d'etre of wind farms, without which none would either be built or operated.

The electricity consumer is footing the bill for a generating system which is unreliable and uncontrollable and can't produce an electricity supply.

In windy conditions the National Grid has asked for them to be shut down. Due to "constraint payments" this is even more profitable for the wind farm owner. Some of these payments are secret and Ofgem has been urged to examine this. Claims of emission reductions remain unsubstantiated.

Wind farms need backup 24/7 from reliable sources.

AR Nelson,

5 Scarletmuir,

Lanark.