Picture of DIY 1000 watt wind turbine
We built a 1000 watt wind turbine to help charge the battery bank that powers our offgrid home. It's a permanent magnet alternator, generating 3 phase ac, rectified to dc, and fed to a charge controller. The magnets spin with the wind, the coils are fixed, so no brushes or slip rings necessary.

Update: DIY Amp Hour meter for monitoring charge!

All about homebrew wind and offgrid power systems, the complete reference!
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Step 1: Build the magnet disks

Picture of Build the magnet disks
We had 12" steel disks hydro cut. We cut a template for mounting the magnets. Then we mounted 12 grade n50 magnets around the outside edge. We then built a form, and poured the resin with hardner.

Step 2: Build the coil disk

Picture of Build the coil disk
We wound the nine individual coils, soldered them in a 3 phase wye configuration, and encased them in resin. We used 35 turns of 2 parallel strands of 14 gauge enameled (magnet) wire for 12 volts. Use 70 turns of single strand for 24 volts. # 3 phase diagram shown here shows 3 stator coils. each of those coils is actually 3 coils in series. coils 1,4, and 7 are series together, 2,5, and 8 are series together, and 3,6, and 9 are series together.

more details, see the following page 15 for the series star, 1-y diagram.


Step 3: Build the bearing assembly

Picture of Build the bearing assembly
Two Harley Davidson wheel bearings are inserted into the pipe, with a smaller pipe locked between them to keep them in place.

Step 4: Construct the blades

The blades are 2" x 6" pine, cut at 10 degrees on a table saw, and sanded into a rough airfoil. Not perfect, but close enough.

More can be found at

Step 5: Further Reading

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I know that programming water jets to cut a out a particular pattern cost quite a bit and so I was wondering if  you would sell the precut disc to those of us who would like to build their own wind turbine. I believe if you were to sell the precut disc, they would help offset the initial cost of programming that you incurred. I can cut them out, but to get the correct balance would take some time that could be better spent on wire winding. Thank you for the information that you have posted and I hope that you might consider this.
sspence (author)  HariKarier11 22 hours ago
I don't have access to a water jet any more. You may want to look around locally.
PatrickJ410 days ago

Thank you for the answer. If you bear with me I some more questions, I appreciate your help.

I have enough 14 AWG wire to make 18 coils of 70 turns each. Before starting anything I would like to know if 6 coils per phase wouldn't be a too long wire. Could I parallel them in 2 pairs of 3?

I also hesitate between one rotor or two rotors. Because I have 48 magnets I would need 2 huge steel plates (24 magnets/each rotor) that will be very heavy. Could I get a similar result if I used one single rotor for all the 48 magnets like a bicycle rim? I would lose flux but i guess I would gain speed since in one revolution 48 magnets would swipe the wires instead of 24.

PatrickJ411 days ago

Hello, please tell me if my understanding is correct: If I have a 12V battery system, when the turbine starts spinning it will create voltage. As long as the voltage is lower than 12V no current will flow to the battery and the turbine will spin relatively easily. When it generates 14V, the battery will bring the system down to its own 12V by drawing the extra 2V as a current and the turbine will be slowed down proportionally with the amps that flow through its wires. When it generates let's say 28V the current that will flow will be caused by the 28-12=16V, so the amps will go up slowing the turbine more. My question is : If I put a 24V battery system then the current that will flow will be caused by 28-24= 4V so the turbine will not be as slowed as in the case of the 12V battery?

sspence (author)  PatrickJ411 days ago
That sounds about right. Which is why, if using a 24v system use one strand of wire instead of two, and double the number of windings.
windrage1 month ago

i converted a house fan into a turbine, how would i go about adding a ratio system to it?

sspence (author)  windrage25 days ago
House fans don't generate electricity. This instructable is about building your own alternator.
someone12231 month ago

If you added more magnet disks and coil disks, would that create more power output? Or would you be better off just making more turbines?

Also can anybody point me to a place where I can get more information on setting up the rectifying diode pack and battery bank?

sspence (author)  someone122325 days ago has lots of articles on batterys, controllers, and off grid systems.
sspence (author)  someone122325 days ago
it could increase voltage, but everything would have to be recalculated. rpm, wire size, the works. Better just to build another turbine.
NicholasG41 month ago

Would This Manget Work? Please Answer

sspence (author)  NicholasG426 days ago
DaveyH27 days ago

How much did it cost you overall? We're considering getting wind and solar energy for our house, but we're working out the numbers right now. So far it's been pretty good, we just have to work out getting enough power as apposed to just getting wired to the grid. I'd personally like to keep our power bill to zero, so we'll probably go this route anyway. Once we get the paperwork out of the way, we'll get to work on building one of these

sspence (author)  DaveyH26 days ago
About $1200 with tower. Prices have gone up over the years.
NicholasG41 month ago

Would This Manget Work? Please Answer

I saw the economy almost go completely down in flames in 2008 and it made me feel very vulnerable to realize how dependent I am on central power and the grocery store. We also just had a pretty rough winter here in TN and several times, I waited through the ice storms to see if the grid power would fail; more dependency.
I need a passive solar home and power generation capability simply for peace of mind.

JohnT123 months ago

I'm curious as to how you determined that this is a 1000 watt generator. I'm working on a small model right now and am not sure what I'll get from it when it's done. About 5 inches in diameter.

I must also say that I've given up completely on lead acid batteries. When yours give up the ghost, check out LiFePo4 cells.

sspence (author)  JohnT123 months ago
Ohms law. number of coil turns, wire gauge. rpm. blade length, wind speed.

Not interested in Lithium based batteries. NiFe, yes.
JohnT12 sspence3 months ago

Thanks for such a quick answer. I also assume the power of the magnets play a factor. I'll have to look in to NiFe batteries. Sounds interesting. I love this stuff.

John kb8uhn

hawks88 JohnT122 months ago

NiFe batteries are pretty outdated. I had to do a quick google search because in this industry, you never know, old tech could make a resurgence, but I didn't see anything. They're basically the armored tank of the battery industry. You can abuse them and they'll last a long time, but they're not that cheap, they have half the energy density of lead acid, and they have issues with holding a charge.

sspence (author)  hawks882 months ago

NiFe batteries have witnessed a recent resurgence with companies like Iron Edison and Be Utility Free producing improved pocket plate versions that are more efficient (75%), and don't self discharge as quickly. They are the the cadillac of batteries because it's almost impossible to kill them, and they can last 50-100 years or more.

Calderick2 months ago
I am an upstart inventor and id like to get in contact with you regarding the specifics of power generation.
sspence (author)  Calderick2 months ago
ttucker102 months ago

couldn't you use a car alternator? I'm not being funny.. Wouldn't that work too?

sspence (author)  ttucker102 months ago
No, it would not. Car alternators have power robbing field coils and are designed to turn at several thousand rpm.
ttucker10 sspence2 months ago
OK thanks

this is all new to me but have been interested in going green for some time. I live in the mountains of North Carolina, so we have wind all the time. I am going camping for an undetermined amount of time. I bought a ten person, 3 room cabin tent so I would not be cramped for space. I have been researching several kinds of windmills and yours really caught my attention. most of the windmills I have looked at won't power much, but yours seems to have the power I need. I need something that will power a dorm frig and a microwave and also charge my laptop and cell phone. I am not really that mechanically inclined, so I will have to have someone help me. is there anyway you can send me step by step instructions and material list?


Robert P.

sspence (author)  horsewhisper60432 months ago
If you need step by step with theory explanations, and a beginners class in electrical generation, I suggest Homebrew wind power
gpoli22 months ago
I'm about to wind the coils and was wandering what lenght u used for the 2 strands of 14 gauge wire?
And how much should the centre spacing be? Or doesn't this affect the coil as long as it has 35 turns?
sspence (author)  gpoli22 months ago
on a 1x2x.5 magnet, each turn is about 7"
guitarplayr23 months ago

Hey, just a quick question I've seen in other designs that all the coils are flush to each other and in this one they are spread out. I was just wondering if you knew if there was a difference between spreading them out like yours or having all the coils touching each other?

sspence (author)  guitarplayr23 months ago
coil size is dependent on magnet size. This is a larger diameter disk, so they don't touch. if the disk was smaller, the power pulses could be a bit smoother. Doesn't matter for battery charging.
puppy_0073 months ago
Hi there ! If i use 20AWG wire and 125 turn with 9 coil star connect .24 magnet 2 rotor at N50 1-1/2 dish . Is that will be good ? Can i get 10-15 amp at 12V with 200-300 rpm . Please thanks
sspence (author)  puppy_0073 months ago
You may very well, depending on wind availability. experiment.
puppy_007 sspence3 months ago
Thanks alot
puppy_0073 months ago
Hi there ! Please tell me how many amps you get at 12v ?
How many rpm at 12v . Thanks in advance !
sspence (author)  puppy_0073 months ago
80+ amps at 650 rpm
puppy_007 sspence3 months ago
Hi ! Thanks for your reply .
Is there any way i can get 12V at 200 or 300 rpm .
I only need 10 or 15 amps at 12V . Thanks
sspence (author)  puppy_0073 months ago

You would have to wind many more turns on the coils to develop voltage at lower rpms. at lower current, you can wind with smaller diameter wire than we used.

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