They cause an impact - and are not green

WITH regard to the recent letter regarding the possible construction of a wind farm within this locality, there are one or two points that may be of interest.

The demand for electrical power varies considerably (and often suddenly) over both very long and very short time periods.

This means that the supply must be capable of meeting this fluctuating demand virtually instantly if power reduction or power cuts are to be avoided.

The way in which demand is equalled by supply is that the generating system runs a percentage of its capacity in the form of "spinning reserve" (generators which are up and running in readiness).

Although the speed of the wind fluctuates greatly, wind farms can only operate over a wind-speed window of something like 8 to 45mph, it should also be noted that the power output from a wind farm decreases in decreased wind speeds.

The coldest days of winter and the hottest days of summer often occur during high pressure (virtually windless) periods, during which there is a demand for electricity for (respectively) heating and cooling, which means an increase in demand over that which would normally be the case.

If we are to have a reliable power supply, then the percentage of total capacity represented by wind farms must be virtually equalled by a reserve of maintained and more reliably fuelled generators.

I fail to see the point of wind farms, they are not reliable, they have a large environmental impact, and (apart from the wind they use) they are not "green".

But we now live in an age where the unwanted can be imposed by the unelected, and so the traveller's site imposers, the developers, the wind farmers, the airport expanders and the rest will all get their way without having to worry about such trivia as public opinion or democracy.

M R HUTCHINS

Ackroyd Road

Royston