Noise of sm. wind generators?

[Brian Funk]

Hey all!

I have a remote, off grid, cabin. It has been powered for years with a small
solar array and a large Honda generator. My battery bank/ array allows for
only a couple days, at best, when it is cloudy and I am spending more and
more time there in the cloudy seasons so I have to run the gen more and
more.

I have added a small Honda generator just to run my battery charger during
dark times, and have been holding off on adding more array till some
building addition issues are settled.

But I have lots of wind (at 10,000 elevation) and have been wondering about
a small wind generator that would be attached directly to the building. 400
watts is probably plenty considering what I already have.

My question, will these new generation, quiet, wind generators be quiet
enough so that I can actually mount it on the roof of my cabin and not be
driven crazy with the sound and vibration?

Any experience out there?

Thanks, brian

 

[Charles]

My question, will these new generation, quiet, wind generators be
quiet enough so that I can actually mount it on the roof of my cabin
and not be driven crazy with the sound and vibration?

The vibration rumble will probably drive you nuts. Can you erect a tower
away from the structure?

 

[[email protected]]

Hey all!

I have a remote, off grid, cabin. It has been powered for years with a small
solar array and a large Honda generator. My battery bank/ array allows for
only a couple days, at best, when it is cloudy and I am spending more and
more time there in the cloudy seasons so I have to run the gen more and
more.

I have added a small Honda generator just to run my battery charger during
dark times, and have been holding off on adding more array till some
building addition issues are settled.

But I have lots of wind (at 10,000 elevation) and have been wondering about
a small wind generator that would be attached directly to the building. 400
watts is probably plenty considering what I already have.

My question, will these new generation, quiet, wind generators be quiet
enough so that I can actually mount it on the roof of my cabin and not be
driven crazy with the sound and vibration?

Any experience out there?

I mounted an Air 403 on a roof scissor-truss roof. Welded up a mount
that transmitted the forces to three trusses, and spread the load even
further with extra wood bracing. All the mounting was internal with
only a stub protruding through the roof. The turbine mast bolted into
the stub. There were two problems - vibration from the turbine drummed
the roof deck and echoed, and the noise was too close to the living
space. I considered putting more work into the mount, but my intention
had been to use three or four turbines, so it became obvious that it
would be simpler and better to use a tower instead, particularly since
a single 1000W turbine was going to produce more energy than four 400W
Airs. The AirX is reported to be considerably quieter, but IMO it's
unlikely that a successful roof mount would be less work than a
light-weight tower.

Here are some links to in dependant testing of the AirX. Keep in mind
that you'll lose some performance at your altitude.
http://www.wind-works.org/articles/sm_AirXtest.html
http://www.nrel.gov/docs/fy03osti/34756.pdf

Wayne

 

[Brian Funk]

The vibration rumble will probably drive you nuts. Can you erect a tower
away from the structure?

I was hoping to use the cabin to add height to the tower as I am close in
lodgepole pine forest. The trees are probably 40'-50' so the 16' of cabin
would have been handy. Could I brace the tower with the house and isolate
the sound from the living quarters? This is a small summer tract area and I
wonder if outside (neighbors) are going to hear the blades?

Beginning to sound like this is not an appropriate technology to throw at my
problem. Perhaps more array and the small Honda eu2000i gen to run just a
battery charger when it is needed will be enough.........

brian

 

[Brian Funk]

It is not a good idea to put your wind generator on the roof. The
noise and vibration of the wind generator can be compared to a heat
pump.

By the way a 400W wind generator (for example Air X) will give 400W
only in optimal conditions. however, it can function 24h/day.

I like that it works day or night, but apparently there is going to be a
noise problem!
I guess I had better find a small wind generator running and give it a
listen. For now a little more solar is probably the way to go.

thanks.........
brian

 

[Brian Funk]

I mounted an Air 403 on a roof scissor-truss roof. Welded up a mount
that transmitted the forces to three trusses, and spread the load even
further with extra wood bracing. All the mounting was internal with
only a stub protruding through the roof. The turbine mast bolted into
the stub. There were two problems - vibration from the turbine drummed
the roof deck and echoed, and the noise was too close to the living
space. I considered putting more work into the mount, but my intention
had been to use three or four turbines, so it became obvious that it
would be simpler and better to use a tower instead, particularly since
a single 1000W turbine was going to produce more energy than four 400W
Airs. The AirX is reported to be considerably quieter, but IMO it's
unlikely that a successful roof mount would be less work than a
light-weight tower.

Thanks for the links. Your set up is a lot more involved than I'd be willing
to do. More array is a lot simpler, especially considering that my cabin is
fully constructed. I'd hate to have to go back inside the structure and
re-build.

brian

 

[Charles]

I was hoping to use the cabin to add height to the tower as I am
close in lodgepole pine forest. The trees are probably 40'-50' so
the 16' of cabin would have been handy.

You'll want to get those blades above the tops of the trees. The wind flow
is too turbulent below that.

I suggest checking your local library for a copy of one of Paul Gipe's books
in which he'll answer all your questions.

If you have the time it's best to, as Gipe suggests, do a survey by erecting
a anemometer and logging the data for many months, even a year. Do you
_really_ have the potential for wind power on that site. It isn't the top
wind speed that's important - average wind speed or more properly power
density is key.

...I wonder if outside (neighbors) are going
to hear the blades?

Yes.

 

[[email protected]]

The truth is that if you can't get your head around
the info then you had best not bother with wind generators.

Nonsense. Most folks who add wind don't get very deep into "info", nor
do they need to. Lots of people spend $500 for Air units or similar,
stick them on all sorts of mounts in all sorts of settings good and
bad, and most are happy with their investment. Even a little wind
energy is a welcome boost to fixed solar because it gets the system
out of that charge-for-a 1/3rd-of-the-time, discharge-for-2/3rds rut.
For example, one neighbor has a pair of Air 403s on short
unguyed-poles in what appeared to be a really crummy location. And yet
they were roaring away when I visited, and he reports that he gets
welcome production from them.

Consider that if you used the time you've spent giving bad advice on
Usenet about wind power, to instead add it to your own setup, then by
now you'd have a better setup *and* perhaps even something worthwhile
to say about the subject. Same with tracking, solar suction, etc.
http://www.citlink.net/~wmbjk/tbfduwisdumb.htm

Wayne

 

[Arnold Walker]

I like that it works day or night, but apparently there is going to be a
noise problem!
I guess I had better find a small wind generator running and give it a
listen. For now a little more solar is probably the way to go.

thanks.........
brian

You thought about mounting your windmill tower in a tree.......instead of on
a house.
Of course,you would have to inch to your windmill treestand up the tree 4
foot every year due to growth.

Of course ,if I was living in the middle of a pine forest which I do ....
I would run gasified biomass with an autostoker like I did for a lot less
than the solar or the wind power.
And for no more than you are talking on wattage. A 3-5hp engine can charge
your battery bank in a hour or so.
But I also have a shop so the steam engine is even bigger for the times you
run the 10KW welder.
(But then if you was thinking about an EV to go with your "green" house.You
would need the same size
powerplant as well.Have your cute little Zap enclosed electric motorcycles
parked in the double garage. )

If you are not getting blade flap(the noise) you are not running any tip
speed for power.
Maybe you should consider going back to a multi blade windmill to increase
the torque instead.
Or .......
Modify a ultra helicopter for high altitude windmill service ......but then
that would be 3to5kw minium in
while autorotating in 30+ mph wind at
15,000ft+.www.treehugger.com/files/2005/03/flying_windmill_1.php
The entire country at 15000-30000ft is blowing at 30-120mph
constantly.Unlike surface wind......
Unisys charts are supplied for the entire North America continent with
dopper updates for 300mbar wind.