Sir - Your column on the new proposed wind turbines includes a suggestion that windmills would replace pylons. Probably even more pylons will be needed.

The existing pylons will be needed for backup when there is no wind. And, since underground cables are ferociously expensive, even when subsidies hide real costs, the wind turbines will need pylons themselves, if they really can produce lots of power.

But inland Oxfordshire is not well placed to deliver much wind power.

The quote of 5,000 houses probably means a rated power sufficient to boil 5,000 kettles (are the proposers afraid of kilowatts?) and, if the efficiency is typical of the 7.7 per cent for other inland wind turbines quoted by the Renewable Energy Foundation (http://www.ref.org.uk/energydata.php), the average will be more like 350 kettles.

It would be useful if the city climate change officer, Paul Spencer, were to publish authenticated efficiencies for wind turbines in and around Oxfordshire. There really must be proper advance tests of efficiency: the climate will only benefit if the carbon savings over the operating life exceed the carbon costs of manufacture and installation. The results of such tests should be available to the public when planning permission is sought. Well-intentioned gestures, whilst tempting, can have harmful impacts.

If we want fewer pylons, a better and shorter-term solution (as the Energy Saving Trust stresses) is to turn down central heating and insulate buildings - homes, shops, and (dare I say it?) even council premises.

Professor Marshall Stoneham FRS, Dorchester-on-Thames