# Air X / Air40 wind generator ?



## TheLazyL (Jun 5, 2012)

Equipment.

12 VDC HAM radio at 100 watts
12 VDC CB at 5 watts.

Inverter for the following:

120 VAC battery charger for AA batteries.
120 VAC sump pump.

12 VDC deep cycle batteries in the basement, 10 feet from the above equipment.

Solar cells in garage attic behind the south facing window. Not the best but the location does keep the solar cells out of site and snow free.

Here is where I need some opinions.

Thinking about a wind generator to supplement the solar. Top off the batteries at night and on cloudy days.

I live in a woods.

I have a 80 foot free standing tower. Tower is 5 feet higher then the top of the trees. Tower is not visible from any public areas.

Tower is approximately 100 feet from deep cycle basement batteries. Add the 80 feet tower height gives me 180 feet from the top of the tower to the batteries.

A 400 watt Air40 wind generator weight is 13 pounds. Mounts on a 1 1/2" mast. I couldn't find a measurement from the blades to the center of the mast (might have to run the mast up 2 feet +- for the 4 foot blades to clear the tower). My calculations show the tower could support the 13 pounds easily. 

Because of the 180 foot distance, the electric cables will have to be run, I'm thinking I'm going to have a large voltage drop? Or very large (and expensive) cables?

My other concern is maintenance on the wind generator. I can still climb the tower for a few more years. If I have to lower the mast and then raise it back up, not sure if I could.

Opinions. A wind generator worth the trouble or not?


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## mosquitomountainman (Jan 25, 2010)

Nice trees! If you have about as much solar as you need the wind generator makes a nice addition. You may need to go higher to get it to run more consistently. Ours tends to stop spinning when it turns with every change in wind direction. Being that close to the same level as the treetops you'll get a lot of swirling wind. (That was the exact problem we were having at home.)

Even with the shortcomings we had with the tower being too short it did manage to top off the batteries during the nights. We've discussed getting a better (taller) tower and another wind charger and probably will in the future. 

Right now we have it in Nevada with us and it's been good but largely unnecessary since we have adequate solar for everything we run. (Still, we plan on keeping this one here.)

We do get more consistent power through the solar panels but like you said, the wind generator really comes in nice on those stormy, windy days with little or no sun.

As you already know, the wiring gets expensive if you have to run a lot of it.

We haven't had to d any maintenance on ours. Once it's up there's nothing to do unless it stops working. Ours has been pretty reliable.

Be sure to put the switch in that full-fields it. We do that with ours when we're going to be gone. If the batteries are full and you get a high wind they can over-speed. That's about the only way to destroy one. We kept the switch turned to full-field it most of the time at home since we seldom needed the wind generator. 

I've used ours to charge dead car batteries also. It works really good for that! I just hook it directly to the battery.


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## Caribou (Aug 18, 2012)

Redundancy is always nice. On my boat I had a solar panel, a wind generator, a towed generator, and the alternator on my engine. Never once did I complain about having too much electricity.

When I was young I used to let people rent me out to do their chores, now I'm the one hiring the young help. Do the work while you can then then hire the help later. You can always direct it from the ground.


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## LincTex (Apr 1, 2011)

http://www.otherpower.com/otherpower_wind.html



> We recommend you start with our The Bottom Line About Wind Turbines article, ( http://otherpower.com/bottom_line.html ) and browse through more in the menu at left. But if you're in a rush...
> 
> Wind power basics in a nutshell:
> 
> ...


http://otherpower.com/bottom_line.html



> Towers
> We've gone over two very important things that we often think about here at Otherpower. The power in the wind is related to the *square* of the blade diameter (double diameter and you get 4 times the power) and the *cube* of the wind speed (doulbe the wind speed and you get 8 times the power). You have a great deal of control over blade diameter -- you can choose what size machine you buy. What about the wind speed? It's often suggested that the most economical choice is to put up lots of machines on short towers, or mount your wind turbine(s) to the roof. Manufacturers say this stuff because it sells machines -- people do not like the idea that a tower costs money, and they love to hear that once they buy the wind turbine very little further cost/effort is required. However, the wind is your fuel and wind turbines need good clean non-turbulent fuel -- and unfortunately you don't find that on the ground or on your roof!
> It is usually suggested by most reputable installers and manufacturers that the most cost-effective arrangement will be to get your wind turbine 30 feet above anything withing 300 feet. If you have turbulent 10 mph winds at 30 feet up and smooth 13 mph winds at 70 feet up then it makes sense to go a bit higher, get out of the turbulence and get into a slightly higher windspeed where you might have *twice* the energy available! This is not the sort of talk that sells wind turbines, but it is reality. In most good installations the cost of the tower is much greater than the cost of the machine itself and there is a good reason for that.


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## Caribou (Aug 18, 2012)

As MMM said, being close to the trees will give yo fluky winds. A vertical axis generator works better in these conditions.


P.S. Trees tend to grow faster than towers.


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## mosquitomountainman (Jan 25, 2010)

LincTex said:


> http://www.otherpower.com/otherpower_wind.html
> http://otherpower.com/bottom_line.html


If a person is relying on wind power they should go with the larger systems. The problem is that everything is going to cost a lot more including the tower, wiring, and generator.

I've read the charts and articles about maximum power vs. wind speed but they don't tell the whole story. You seldom need maximum power to supplement your solar power system. It's surprising what an extra 10 to 20 amps of power applied over a 24 hour period will do to recharge a battery bank.

It's also being applied while the solar panels are winding down in the evenings and getting started in the mornings so it gives the system a boost in mornings and even if it doesn't keep up with power drain or usage it will slow the discharge rate of the battery bank in those times of low solar output.

The key is to use wind as a supplement to your solar power system. It makes a good supplement because usually those days when you get the least sun are also those stormy days with more wind so the systems tend to balance each other out. Most of the time we put ours into the "idling" mode unless conditions deteriorate for making solar power.

The other thing is that during those dark and stormy nights when the wind tries to send all your belongings (including your solar panels) to the land of OZ you'll hear the whine of that wind turbine just working it's little heart out to keep that battery bank full.

For those of us living off-grid it's nice to not have to shut down everything electrical but the "essentials" during times like that. In fact, it's often the best time to run everything electrical to keep the wind generator from spinning too fast. We've loved having ours down here in the desert during the Santa Anna wind storms. We can't do anything outside due to wind and blowing sand so we put some DVD's on to keep the grandson occupied and we get some computer time in.

Don't discount the effectiveness of the small, cheaper wind generators. They have their place in off-grid systems.


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## mosquitomountainman (Jan 25, 2010)

Caribou said:


> As MMM said, being close to the trees will give yo fluky winds. A vertical axis generator works better in these conditions.
> 
> P.S. Trees tend to grow faster than towers.


That's what we've been thinking about for our Montana place.


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## LincTex (Apr 1, 2011)

mosquitomountainman said:


> Don't discount the effectiveness of the small, cheaper wind generators. They have their place in off-grid systems.


I agree, as long as a person doesn't buy junk. 

I just like to play devil's advocate at times, as it helps people make informed decisions when they can see both sides of the issue.

I meet a lot of people who have never seen where their location lies on a wind speed zone map, and then want to erect a wind turbine in an area that never sees wind over 10 mph?


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## Viking (Mar 16, 2009)

Caribou said:


> As MMM said, being close to the trees will give yo fluky winds. A vertical axis generator works better in these conditions.
> 
> P.S. Trees tend to grow faster than towers.


When I was doing research into additions to the solar power and alternatives to the forced air propane furnace in our motor home I ran across some websites that were for boat supplies. I saw the vertical axis generator, what a great thing, automatically dumps excess wind speed so they don't over-speed. They kind of look like the fan core in a squirrel cage fan. As to an alternative to propane I was looking at diesel fired compact wall type heaters, the sites had them but boy were they expensive.


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## cowboyhermit (Nov 10, 2012)

Viking said:


> ...I saw the vertical axis generator, what a great thing, automatically dumps excess wind speed so they don't over-speed. They kind of look like the fan core in a squirrel cage fan. ...


There are all kinds of VAWTs these days, I have even installed ones that are mounted to the "whirlybird" type vents. Some of them are pretty low output but IME very low maintenance. They are also BY FAR the easiest type to DIY, plans are even around to make them from plastic barrels or buckets.

They can easily be designed to handle low wind speeds, turbulent winds, etc, and can even be connected together to power 1 generator.


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