Wind Energy and Reality
Dear Sir
I am a retired engineer who worked in the energy field for many years.
I would like to suggest that each time you publish information about the number
and size of the latest wind farms and the population of
the towns they can support you should always add in brackets (when the wind
is blowing at the necessary speed).
Most of the wind turbines being built today only generate
their rated output when the wind is blowing at about
25 miles per hour.
The energy available in the wind varies as the cube of the
velocity.
It follows that if the wind speed is halved then the output from the
turbine will be one eighth of the rated output.
If the wind speed is 8 mph then the energy available will
be about one twenty-seventh of the rated output.
It is interesting to view the BBC weather maps which
quote the wind speeds and form your own views as to the
likely output of these machines.
There is much information on the internet about the rated
output of small wind turbines but very little information
about the actual kilowatt-hours being generated.
If the actual output of these devices was available and
compared with the rated output I believe it would throw into
doubt the whole wind energy programme.
D.D.
