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Politics : PRESIDENT GEORGE W. BUSH -- Ignore unavailable to you. Want to Upgrade?

To: Krowbar who wrote (536266)	2/5/2004 8:58:00 PM
From: Jagfan	Read Replies (2) \| Respond to of 769670

Losing your grip? Environmental Effects of Windfarms By Richard S. Courtney Thermal power stations release pollutants but windfarms don't. This implies that use of windfarms could reduce pollution from fossil fuelled and nuclear power stations. But it can't. Any such reduction - if achieved - would be so insignificant that it would probably be unmeasurable. In fact, the use of windfarms is more likely to increase emissions than to reduce them. And if a trivial reduction in emissions were obtained, it would be purchased at immense financial and environmental cost. Windfarms only generate electricity when they are working. And they only work when the wind is strong enough, and not too strong. But electricity is needed all the time. Thermal power stations provide the needed electricity when the windfarms are not working. Thermal power stations take time to be switched on and off. They use the heat from nuclear reactors or burning fuel (e.g. coal, oil, or gas) to boil water and to superheat the resulting steam. The superheated steam is fed to the turbines of turbogenerators that produce electricity. It takes time to boil water and to raise the power station to operating temperatures. A typical 2GW power station takes days to reach normal operating conditions from a cold start. The time to run-up a thermal power station provides difficulty to electricity suppliers. Demand for electricity varies throughout each day, from day to day, and from month to month. Most power stations are used to produce needed electricity. Other power stations are also operated on "spinning stand-by" so they can immediately provide electricity as demand for power increases (or if a used power station fails). Of course, the operation of these other power stations to provide the needed back-up releases all the emissions from burning (or fission) of the fuel needed to keep them hot. The use of windfarms does not replace thermal power stations. It requires used thermal power stations to operate on "spinning stand-by" so they can immediately provide electricity when the windfarms stop, because the wind speed has changed too much. Simply, 1. Most existing back-up compensates for fluctuations in electricity demand, 2. windfarms provide additional fluctuation to electricity supply, and 3. additional back-up is needed to compensate for the additional fluctuation. Each windfarm increases the risk of supply failure by the amount of its output. It does not reduce the existing need for back-up. But some people claim the existing back-up could accommodate the additional fluctuation to power supply provided by use of windfarms. They are wrong. "Spinning back-up" costs money that the generators don't spend willingly. The generators now only operate the back-up they need to cope with expected existing demand and supply fluctuations. Additional risk of supply failure requires additional back-up, if power failures are to be avoided. And a windfarm provides the risk - indeed, the certainty - that its supply will fail when the wind changes too much. Simply, windfarms cannot provide significant displacement of the need to use thermal power stations. Windfarms require operation of thermal power stations to provide electricity when the wind is wrong. And windfarms require operation of thermal power stations on "spinning stand-by" to provide back-up when the wind is right. Weather prediction can reduce the need for additional back-up provided by windfarms. But this reduction is slight because a windfarm may operate when the wind speed is nearly too strong or nearly too weak. And local wind prediction is difficult. The most effective wind prediction is that wind will be most constant on exposed hilltops or at sea. And this prediction leads to the call for windfarms to be sited in such places. But these sites cause direct environmental damage. Hilltop and headland windfarms are very visible, change skylines, and cause large areas of unspoilt land to be covered in tarmac and concrete. Each wind turbine needs a foundation, a service road to permit maintenance, and power lines from it. More service roads and power lines are needed from each windfarm. Off-shore windfarms have similar environmental effects to hilltop windfarms, except the environmental damage is to sea bottom. Also, they increase hazard to shipping and may affect coastal currents, with risk of alteration to coastal erosion patterns. Other significant environmental effects include noise and hazard to birds. A wind turbine blade removes energy from the air that passes it, and the blade moves through a circle. The removed energy reduces the pressure of the air and, therefore, pulses of reduced pressure flow downwind from an efficient wind turbine blade. These pulses are heard as noise. To date, no significant research has been published concerning effects of this noise on wildlife, but it seems likely that it could affect breeding rituals and habits of some species. The noise is certainly unpleasant for people whose homes are subjected to it. Birds die when struck by wind turbine blades. Several studies report that wind turbines kill thousands of birds in California each year. All of these problems would be worth suffering if wind power were cheap. But it is not, and it never can be. For centuries, wind power was used for shipping, pumping, and grain milling. But its use for these purposes was abandoned when fossil fuels became available. Today, if wind power were economic, oil tankers would be sailing ships. Wind power cannot displace the use of fossil fuels. Wind power cannot compete with the immense energy available from use of fossil fuels or nuclear power. This is because a wind turbine has high capital and maintenance costs, but it generates small amounts of useful energy. These costs mean wind power will always be expensive, because no wind turbine will ever generate much useful energy. None will. Not ever. Wind is moving air, and air has low density. e = 1/2 m v2 When its mass (m) is small, its energy (e) is small - unless its velocity (v) is high. The mass of much moving air (i.e. wind) is small and windfarms don't operate when the wind velocity is high. "Ye canna' buck the laws of physics, Cap'n." Wind farms are expensive, polluting, environmentally damaging, noisy, bird swatters. For the environment's sake, everyone should unite in a campaign to get them banned. eco.freedom.org