"Peter Parry" wrote in message
...
On Mon, 8 Jun 2009 18:15:28 +0100, PeterC
wrote:

Just found an item about a wind turbine that doesn't have a gearbox to
waste energy and runs at 2 - 45 mph. One of my dislike about these
contraptions is the amount of gubbins to run before anything useful comes
out. This one is pretty well a wind-driven electric motor:

http://www.earthtronics.com/honeywell.aspx

More complete ecobollox actually. At 10MPH wind speed (Gentle Breeze
Leaves and small twigs in constant motion; wind extends light flag.)
it generates a magnificent 100W. Its power curve isn't much different
from other of these daft windmills. Admittedly it generates about
10W at 5MPH when most others are sitting idle but that won't even turn
the inverter on.

In most urban environments it will probably match the performance
found in the Warwick trials

http://www.warwickwindtrials.org.uk/resources/Warwick+Wind+Trials+Final+Report+.pdf

"The average energy generated per turbine per day across the sample
set has been 214 Wh...This is equivalent to an average of 78 kWh of
energy produced per site per year and an average capacity factor of
0.85%."

"Of particular note is that turbines on our high rise sites, ... were
able generate as much energy in one month as other turbines in the
trial did in one year. It is unfortunate that these high performing
turbines had to remain switched off for the majority of the trial
following complaints about noise from the building residents."

"The poorest site generated an average of 41Wh per day when in
operation or 15 kWh per year, which is less than the energy it
consumed to run the turbine's electronics"

I always wonder with these things, particularly when there's a field full of
them, whether that old phrase "you don't get owt for nowt" applies, and
'stealing' that bit of power from the wind causes any knock-on problems down
the line. Sort of 'butterfly effect' if you like. Wouldn't it be something,
if some bright spark worked out that by the green mist brigade saving the
planet and generating a few MW of electrical energy here, they caused
devastating floods in India ... d;~}

Arfa