WIND farms are not only of no use when there is no wind, they have to be switched off when there is a strong wind, for fear they will self-destruct. J C Hindson (Letters, June 2) is right to complain about the lack of use of hydro-electric power from reservoirs. Tavistock used to have its own hydro-electric plant on the Tavy at Mary Tavy and there is a house at Chagford which has used hydro electricity off a leat since the 1880s. Low level hydro plants on water sources, which can be easily camouflaged, are less destructive to the environment than wind farms. Particularly if you live near one. Recent scientific reports state that many of the animals which became extinct 30-40,000 years ago died out because of climate change. Climate change?, 40,000 years ago? Where were the fume belching gas guzzlers, factories and power stations which are now blamed for today?s climate change? Perhaps it was all the fault of the people of those times using too much bio fuel for cooking and heating. Beware the bio-mass power stations! J W Reid Limehayes Road Okehampton