Brian Parker, of Crossparks, Dartmouth, writes: It may not be obvious at first sight, but there is a link between your headline story on the increasing numbers of Dartmouth households ­experiencing energy poverty (Christmas poverty plea by food bank, November 14) and the article detailing proposals for a wind turbine north of Old Mill. It is because of such ­installations that energy bills have increased, and they will continue to do so year-on-year in the long term as wind ­turbines continue to be installed. The reason is that electricity generation from wind is supported by substantial subsidies chargeable to the consumer, making it more expensive than from conventional plant, and this has contributed to the rise in energy bills. The installation of the ­generator at Downton Park Farm adds to that cost excess and will nudge yet more Dartmouth families towards energy poverty. In the same issue are letters supporting the wind turbine proposal. I can understand that farmers, who have a living to make, welcome the potential income from renewable energy installations. The letter from Alice Sharam expresses her 'family's full support for the turbine at Downton Park Farm'. Unfortunately, although I am an environmental ­scientist, I cannot share her enthusiasm for this form of clean energy. There is a great deal to be said against wind generators. The concerns about visual intrusion in a designated landscape are well-voiced by others and I will here concentrate on the technical issues. You may have wondered, with all this 'free' energy, why the windmills of yesteryear ­disappeared and were not developed into more modern machines. The answer is that the amount of energy available from the wind was piddling. It still is. The Downton Park ­turbine, despite its impressive height – equivalent to Exeter Cathedral – will generate on average throughout the year enough energy to supply the needs of just half of Dittisham (arithmetic given at the end of my letter). This leads to the inevitable conclusion that, if the Government continues with its targets for much more wind power, and offshore generation, recently out of favour, remains so, there will be very many more onshore turbines needed. To add five per cent to national generating capacity would mean another 60,000 (yes, 60,000) turbines the size of that proposed for Downton Park Farm spread around the windier parts of the country, which includes the South Hams. A serious issue with wind generators is noise intrusion. Alice Sharam is wrong to ­dismiss it. Recent peer-reviewed research in the USA has shown that turbine noise 'does harm sleep and health'. It appears that the decibel level of the noise is less important than its low-frequency regular ­pulsations, if present, being particularly disturbing over considerable distances. Planners taking note of this are increasing the minimum ­turbine-to-dwelling separation. Wiltshire County Council, for example, is increasing the ­distance from 0.6 to 1.8 miles, depending on generator size. The Wiltshire minimum is rather more than the 35dbA (acoustic decibels) distance on the projected plan. Finally, about wind generation being 'clean' energy. Yes, but there is a caveat. The energy and carbon costs of manufacture, installation and operation are significant. You may be ­surprised to learn that, kilowatt for kilowatt, the energy and ­carbon deficits for starting an operation are the same for wind power as for nuclear power. Arithmetic: the proposed Endurance X29 wind turbine has an output of 225kW. The average generation throughout the year is likely to be 20-25 per cent, giving 50kW. With the commonly used factor of 1kW per household, this supplies, on average, some 50 households, around half of Dittisham. Total generation is around 60,000MW. Five per cent of this is 3,000MW, divided by 50kW to give 60,000MW.