The past week has been bliss for those of us in the central belt who love sunny days and starry nights, but it must have been unproductive for the wind turbines which scar the Braes of Doune. Every time I have looked, they have been immobile. Can the proponents of wind power tell us how many weeks like this they factor into their claims for effective production? Also what is supposed to make up the shortfall when the turbines are not operating, and what happens to this alternative power source when the turbines start again? Is it on expensive stand by?

Fiona Robertson, The Garrique, Kippen.