Tom Changes Wind Turbines

 

This is a note from Tom Sullivan explaining a major change to his wind turbine installation:

 

 

 After 18 months of low production numbers on my Breezy, combined with noise issues my wife and neighbors were more than a little tolerant about, I decided to take the Breezy down and try another option. I befriended a retired EE / PE, Larry, who was playing with a homebuilt permanent magnet machine in a parking lot, on the 4th of July this year. I couldn't resist stopping to see what he was working with. When I disclosed to him about my Breezy and 140' tower, he all but insisted on seeing it that same day (and he did). Larry took the Breezy builders book home and studied it, looked at the website, and reviewed my low production problems. His assessment was we (our area of the country) don't have enough wind to support the narrow band of generation that is inherent to an "induction motor based" wind turbine (at least of this design). He offered me the use of a 1935-1950's era 1800 watt Jacobs he had obtained, He had recently gone through the generator motor and had tested it with a set of plastic blades, without a tail and in a down wind mode, as the plastic blade rotation was backwards from the original Jacobs design. He was interested in seeing it operate in a good location (up high on a tower), and would help me with the slip ring fabrication and controls. I would need to build (or buy) new blades, fabricate the bearing assembly and tail structure, and build or find a tail vane.

 

 



I needed to keep the investment low, as my wife was no longer tolerant of serious investment in wind energy, given the poor production results of the last venture. I laminated and carved my own blades, using the damaged originals as a template. We fabricated the tail structure out of the same size angle iron used by the factory in 1935. The original tail was steel, but finding one in serviceable condition, close to me, was not an option. I obtained the weight of the original tail from another builder (those guys on Field Lines are awesome) and was able to use 1/2" "sign board" plywood, matching the original tail vane weight pretty close. I sealed the end grain with spot putty, and installed numerous coats of high quality automotive epoxy paint on it. About this time I discovered this was becoming more of a labor of love; a restoration more than a project. I decided to body work and paint the two dome covers for the motor, and the spinner for the prop. I then sand blasted all the hardware and the variable pitch hub, and painted that with the same high quality automotive paint. While checking the hub over, I discovered the bearings were shot on one of the shafts. This is a pretty complicated pitch mechanism, and production would be affected by one blade not tracking true, so I completely rebuilt the hub. I painted the "fly weights" black so I could see when they were working, extending out from the hub, as the governor control in high winds. I assembled the unit on the ground in front of my garage, testing the fit of everything.





Since I was now going to be making DC power, and at a much higher amperage than the previous unit (possibly as high as 60 amps), I needed larger wire. Again, trying to avoid a major expense, I scrounged around until I found enough used wire meeting the amperage rating this turbine would generate. Most of it came from a friend with a gravel pit; wire he saves and uses for powering the various pieces of equipment in the pit. I ended up with 2 gauge aluminum for most of the wiring run, and a disconnect for the base of the tower that would accept that size wire was pretty expensive. I found an old "knife switch" disconnect laying out in the weather at the pit, with a mouse nest in it. I cleaned it up, sandblasted it, and painted it gray (it looked like new when I was done). We briefly thought about grid tie on this unit, but decided to keep it simple and hook directly from the controller to heating elements in my solar storage tank. Since recently connecting my hot tub to my solar tank, via a stainless steel heat exchanger, I can use almost every bit of extra heat that tank will accumulate. ( http://www.aluminum-solar-absorbers.com/solar-hot-tub.html )

We went live about a month ago, and the unit is quiet, runs almost always, and is on pace to generate 3-4 times the annual production of the Breezy. There is something to be said about matching the wind turbine to your wind resource. This unit will generate 200 watts all day long in light winds, and it will crank out 1,000 watts in a decent wind; all this while you can't hear it run. I've discovered I set the blade angles improperly (the factory provided a gauge, which I don't have). I will be dropping it down shortly for an inspection and to reset the blade angles. I expect to see production climb a bit more after that. Regardless, I can't say enough how happy I am with this old "restored" jenny.

For more info and pictures;
http://www.aluminum-solar-absorbers.com/wind-power-projects.html

As far as the Breezy, here's my thoughts. If you are in a good wind zone, high "3"s, preferably 4-5, you will probably be satisfied with the unit. I understand they now have a "soft start" option that will substantially reduce the "clanging" I was getting every time the unit would lock in (which in marginal winds can be several times a minute). The other noise was blade noise. If the blades are made "per instructions" they leave a rounded off edge about 1/4" thick. After communicating with a large pool of builders from Field Lines

 

 during my project, it's evident this is a no-no. A thin trailing edge reduces noise, and another Breezy builder about 60 miles east of me has removed and modified his blades to this thin trailing edge. He noted his blade noise went down significantly. That leaves the production issue, which I just don't think is realistic in lower wind zones. This turbine will be a worthwhile project for someone with good wind. If you are like me, with marginal winds, stick to a unit with a lower "start-up generation" threshold. You'll be much happier with your investment.

Tom
 

 

 

 

 

Gary November 21, 2010