VAWT around a wide mast

[betwixt]

I'm in a remote rural location with 3-phase electricity provided via tall wood poles and overhead cables. In a month or so, the cables are being replaced with underground ones as the existing bare cables are constantly shorting when the wind blows and when tree branches snag them.

When the new cables are in, I will be free to remove the old ones but it occurred to me there could be an opportunity to do some experimenting. One thing that comes to mind is building VAWT turbines. In my mind I'm picturing a shaft and bearing at the tip of the pole and a cage/vane assembly surrounding the top of it. The cage hopefully rotating and doing something useful in the process. The poles are in small clearings in woodland but there is insufficient space to mount a conventional horizontal axis turbine. The location is fairly windy but the trees will be causing quite a lot of turbulence.

I'm not expecting gigawatts of electricity, just curious to know if anyone has made a top mounted turbine with a 10 inch (25cm) wooden shaft runing through it before and can comment on the idea. The maximum width it could run to would be about 3 feet (1 metre).

Brian.

[vawtman]

Did they do it for free?I was lucky back in the day all i had to do is buy the base.

Not sure on the rest of your thoughts though.A sorta drawing?

Mark

[fcfcfc]

Hi: I have thought about that before looking at all the AL light poles in shopping malls. The power cable is already there for grid tie etc.. The trick is how to hook the gen so as not to have it around the pole. The upper, middle and lower turbine support rings you could always do in two halves. The gen though would be a different matter. The pole gives you all that rigidity which is nice... saves money too...

[Norm]

Why not have an alternator that wraps around the pole? Anyone that's ever built an alternator

could do it.

Or even a chain drive with a ring chain wheel to

the generator?

[spinningmagnets]

As others have said, there are many ways to de-fur a curious feline (no cats were harmed in making this metaphor...)

Just a couple of ideas that come to mind. On the top of the pole, mount a truck spindle and brake disc. Connect a large wooden disc to it (4'?). If the pole is 10" in diameter, slide a section of heavy duty 12" plastic pipe over it with the top connected to the bottom of the upper disc.

For the bottom bearing, cut 5 radial slots near the bottom edge of the central pipe and install 5 small wheels. You can form a race for the wheels if you want by sliding a short section of 11" plastic pipe onto the section where the wheels will run. fill any gap between the race and pole with epoxy and secure with countersunk screws.

Attach another 4' disc near the bottom of the central pipe, and you can install a variety of VAWT blade types between the two discs. If you cut a thin shallow goove up the side of the pole before anything else is installed, you can insert a 1/4" stainless steel hydraulic tube/brake-line to allow you to grease the upper bearing from the ground.

For the PMA drive, perhaps mount a toothed belt pulley about 24" in diameter to the bottom of the lower disc. Mount a plate to the pole just below the VAWT, with a pulley just above the PMA that aligns with the VAWT pulley.

Not hat anyone would actually use this particular configuration, but, I'd start with making a small platform like a deer-hunting tree-stand. Make a small pole-crane with a swing-arm and 12-volt winch. Shape the swing-arm like a rotating "T" with a water-fillable counterweight on the end thats opposite to the pulley.

After you have the platform and crane in place, attach the PMA mounting plate and slide two of the toothed belts over the pole (one to use, and one for a replacement so you don't have to remove the whole VAWT for a new belt).

Cut, shape, and pre-assemble in the shop, then dis-assemble the pieces for installation.

If you're dead-set against a belt drive, I'm sure there's a couple ways to mount a direct drive to the top, and run wires down a side groove (maybe even direct-drive on the bottom...)

Lately, I've noticed the gas and electric companies are getting material on plastic and metal 6' X 6' reels instead of the old wooden reels. Might be a source for raw material?

[Drawbar]

I'm just amazed the power company has not installed limb chopper circuit breakers on their lines. Where I live,which is one of the last houses on this line, the trees would often trip the breaker. I live in Maine and this state is the most heaviliest forested state in the nation. Finally the local power company installed limb chopper breakers and its very seldom that we lose our power now.

I am not sure they work without doing damage to peoples homes,but after a limb hits the powerlines, the breaker trips. About 5 seconds later it sends a surge of high voltage electricity down the line and literally blows away any limb that tripped the breaker. After that the circuit breaker resets itself and all you have is a few seconds of non-power in your home. They use them on most high transmission lines too.

Regardless,and back to the issue at hand...

I liked the ideas of the poster above me, but I am wondering if belt drives cause too much friction loss? A few ideas I had were using steel cable instead. If there was not enough friction between the sheaves and wire rope, a custom machined sheave with sections of rubber or wood could be added to the sheave at certain intervals to get the cable to have the proper grip, but not too much adhesion either.

Other ideas include using leather belting instead of kevlar or rubber v belts, or as the old timers often used, simple manilia ropes to reduce friction loses. Probably these are all silly ideas, but I post them nonetheless.

[thefinis]

Well a few things come to mind. Are the poles on your land? If not then you may have a problem. Also as it is in heavy forest with the lines and poles below the top canopy of the trees so your wind is limited as well as being turbulent. Next do you have any idea how much line loss there is in those long spans between poles? You are going to have to erect the turbines on a standing pole 30 ft? up in the air. Not an easy task even when everything is at ground level.

I think that you would probably be better off to just build a good tower as close as possible to home and put one large turbine on it. Even if you make this work and have a string of wind turbines tied together with the old power lines the problem of shorting is still there. I can not quite see how to tie a string of turbines together or what would happen with random shorts occurring in the system.

Take care keep dreaming

Finis

[pepa]

this experiment mav give you some ideas, more photos in my files, pepa

[Sparky01]

Hey Drawbar where are you located in Maine? I live in Unity and was beginning to wonder if there was anyone in my neck of the woods that was into windpower and RE.