This wind turbine is basically built from the Prairie Turbines design ( http://www.prairieturbines.com/ ). Their assembly manual is pretty good, better than most I have researched or purchased. I have incorporated many ideas of my own, but the project could not have proceeded without their help and resources. Their web site has a lot of good information and pictures.
This generator is designed for grid-tie applications only. It generates up to 5.5 KWs of A.C. power, unlike most smaller units used today that generate varying levels of D.C. power. D.C systems are nice, but require batteries and/or inverters. The Prairie Turbine design fit the application I was looking for.
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Major Update on Tom's Turbine Project
Tom has made a major change to his turbine project -- all the details here...
Quite a project!!
Thanks very much to Tom for providing this material!
Tom will answer email questions -- you can reach him at: toms1 AT chartermi DOT net (replace At with @, DOT with .)
Tom has sent in several great renewable energy projects ...
Update from Tom -- September 1, 2009
Tom is having some difficulties with the wind turbine project -- the update below goes through the details. It looks like its on the way to a successful resolution. Tom will let know when he gets the new blades and any updates to the turbine installed -- stay tuned.
Here is an update on my wind turbine:
Production through the 2008/2009 winter was fairly
disappointing, but several factors need to be considered. Before
it got real cold, I was getting about 100 KWH a month, not what I
was expecting, but at least measurable production. Seeing
marginal production, and what appeared to blade inefficiency as
the cause of my low production, I designed, fabricated, and
installed an aggressive set of blades for the turbine (pictures
attached). I dropped the unit the first week of December and
installed them, and the unit went into "over-speed less than 10
minutes after raising the unit. With some definite
disappointment (the new blades took me a pile of hours to make), I
dropped it down right back down and reinstalled the original blades.
Once I hit the late December U.P. weather, production dropped,
as available wind power went up (what??). I finally realized the
80-90 gear lube we had placed in the gear box was so cold, it was
stopping the turbine blades from turning, even in 25-30 MPH
winds. Having had rotator cuff surgery the first week of
December, I had no choice but to wait until spring to drop the
unit down to change the oil.
Late March / early April winds brought fantastic production,
compared to what I had seen since going live. I saw well over 200
KW in a 25 day window. Not the 400-600 KWH per month expected when
taking on this project, but still exciting. The cold temps were
no longer affecting the oil in the gear box. Starting in May I
was getting shut downs of the unit more frequent than before
(appeared to be over speed protection), and by June/July it was
tripping the reset in any decent wind. I had yet to drop the unit
for maintenance, so on July 31st I dropped it down to inspect it
for the first time since early December.
Prairie Turbines had indicated both the production problem and
the "over-speed shut down" problem could be deriving from the
magnetic pick-up circuit or a resistance (or arcing) of a
connection in the wiring circuit. Upon dropping it, the first
thing I noticed was the magnet for the magnetic pick-up appeared
to have been rubbing on the sensor mount. I now recall tightening
the gap a bit while first testing the unit when it would not
engage ( a problem later determined to be from the 5 minute delay
device I was unaware of ). I had never opened the gap back to the
recommended amount. The second thing I found was I had used
"Spade connectors" for my connection between the wires running up
the tower to the wires on the slip ring. The intention was for
easy service and/or removal of the generator from the tower. One
of the 120 volt main charge wires was loose in the spade
connector, a clear possible resistance point. I will use more
permanent connections when reinstalling the wiring. The third
item found was a design fault with my bearing. Although
the bearing was still working fine, it was moving within my
fabricated housing. The stresses of 30-40 MPH winds at 140' on
those blades, and ultimately the generator, are more than you
would think. Some simple modifications to the bearing housing
addressed this issue.
I have yet to inspect the remaining wire connections (those at
the base and control unit), but feel even the items found so far
will impact performance. Tim, at Prairie Turbine, has some
upgrades in the works for turbines in the low wind conditions we
see in the Mid-west, as it appears I'm not the only builder
with disappointing production numbers. I will say, I've spoken
with a builder in Saskatchewan that has gotten impressive
production from his unit, enough he is now building a 10 KW unit
of the same design. Tim also thinks my newer blades may work if
tweaked a bit (less pitch, which can be accomplished with a new
blade mount and maybe shortening the blades a bit). My
production, with the noted problems is just over 500 KW in 6
months. If I can just get to 300 KWH a month I'll be happy.
Gary, October 29, 2008, September 3, 2009