I visited the windfarm near Ravenshoe
up on the Queensland tablelands. Ravenshoe, the near
by town, is the highest place in Queensland, close to
900 meters above sea level. The windfarm is operated
my Stanwell, and consists of 20 turbines, with a total
output of 12 Mega Watts.
I meet up with the site manager, Bruce
Chappell, and went through a generic site induction.
Bruce then took us up to one of the windmills and we
had a look inside. In the base of the tower is the windmill
control logic and high power inverters. The windmills
operate at 20 RPM, and generate 3 phase AC at a different
frequencies to the grid supply, so the inverters convert
the windmill AC to mains frequency. The AC then then
fed into step up transformers where it is converted
to 22kv and then 66kv for feeding into the grid.
The towers them selves act as cooling
for the windmill. Air is circulated from the alternator
at the top of the tower and through the inverters into
the tower space where it is cooled by the steel tower
The control logic takes care of yaw
and blade pitch. There is a small weather station at
the top of the windmill that gathers data used by the
control logic. The windmills also log this weather data,
as well as operating parameters ( blade pitch, power
output, etc.). This data is sent to a near by office
for recording and monthly reports.
Each windmill has a blade length of
22 meters, and the turbine center is 46 meters above
ground level. While we were there the turbine was running
at 20RPM, and I worked out the tips were traveling at
180kmh, give or take.
The windmills make almost no noise.
From the visitors car park you could just hear the closest
windmill( about 50 meters away ) as the blades swept
Up to July 2006 the windfarm
generated 162.75 Gigga Watt Hrs of electricity, with
a saving of approx 164,500 Tons of CO2 Gas.
You can click on the photos below to
see the original picture. The originals are large, so
please allow time for them to display.