Ref: Paul Taylor's posting Wed, 12 Apr 2006 08:25:54 +1000.
Note: I am not criticising Paul Taylor; I am simply commenting on a statement
in the content of the
posting.
Paul is quoting from another source and I am suspicious of sources such as
Wikipedia.
Quote:
"The small turbines are dangerous to various raptors that hunt
California Ground Squirrels in the area. The larger units turn slower
and, being elevated higher, are less hazardous to the local wildlife."
I don't understand the reasoning.
If the squirrels can climb the towers then it wouldn't matter how high they
were.
I would have thought that tall towers would be more hazardous to birds,
including raptors.
Larger turbines would have longer blades. Longer blades would probably spin at
lower revolutions
than shorter blades.
However, the tip speed of longer blades would still be extremely high even at
low revs.
I believe that the tip speed may be in excess of the speed of sound.
(Hence the noise problem.)
At such speeds the significant part of the blade would probably be 'invisible',
at least to human
eyes.
Perhaps they are also 'invisible' to the eyes of birds?
I would also think that the height of the tower has more to do with the length
of the blades than
anything else and, no matter how high the tower, the tips of the blades would
always be at about the
same minimum height from the ground.
Also:
Ref: "windfarms" posted by Terry Bishop, Tue, 11 Apr 2006 18:43:21 +1000.
Terry said:
"Located on Carcoar Dam, south of Orange NSW, Blayney Wind Farm is one of the
largest in New South
Wales. The wind farm consists of 15 turbines. Each of these is 45 meters high
with a rotor diameter
exceeding 45 meters. The capacity of each turbine is 660kW and the total
generation of the farm is
9.9MW."
Such a windfarm is, in my opinion, insignificant and is not a reasonable
example to quote when
examining the issues involved.
Before wind generation of power could be considered viable in this country that
farm would have to
be magnified several thousand times.
Imagine that!
Of course, the provision of windfarms will probably follow the same principle
as that used in 'land
development': small windfarms will be installed at a regular rate spaced a significant distance
apart;
these farms would then be expanded gradually until they join up in several very
big farms covering
very large tracts of land. By the time the effect is really noticeable it is
too late.
Cheers
Bob Inglis
Sandstone Point
SE Qld
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