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.

Step 1: 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

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.

http://www3.telus.net/faheydumas/Wind_Turbine/Forum/AXIAL_FLUX_HowItWorks.pdf

Step 3: 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

http://tech.groups.yahoo.com/group/axialflux/

http://www.green-trust.org

http://youtube.com/watch?v=o9EEHFKEckM

Step 5: Further Reading

More info can be found at 

http://www.green-trust.org/freebooks/

and

http://goo.gl/ywhQp

Comments

[bluecowz]

do you have the instructions in fine detail some where for those of us who get lost when every detail isn't posted? Would love to see if my hubby would make this with me but I'm not sure how the magnets were affixed, sizes for things, thickness of the resin, etc... Also, do you have suggestions for a micro sized unit? In my neighborhood I can put a certain sized one on my house, but otherwise i cannot have a larger unit. It's very windy where I live and the wind usually comes from the east so I was thinking maybe a fixed panel of small rotors. Thank you.

[Javin007]

Gotta agree with bluecowz here. I'd love to build a similar unit, but I'd need a LOT more detail. For instance, at this point:

"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."

I would be far more likely to understand this if this were broken into about 5 steps with pictures. Should I assume the different colors are wired together? If so, why? How does the current get converted to DC? How does it get stored? How do you "plug in" to the final product? So many questions left!

[sspence]

What you asked for was explained. Every third coil is in series, the color codes help you keep it straight. Current gets converted to dc through a 3 phase diode, almost identical to your car alternator. The diode bank plugs into a battery bank. Battery banks feed inverters producing ac.

[Macattacku]

If u want to generate over 30% more power at 12volts then change the windings to 24 volts and the change it to a delta 3 phase formation instead of star formation. This will bring it back to 12volts. At higher speeds it is more efficient therefore generating more power.

[hamid manzoor]

What is power of your individual magnet??

in Tesla??

[sspence]

The grade, or "N rating" of the magnet refers to the Maximum Energy Product of the material that the magnet is made from. It refers to the maximum strength that the material can be magnetized to. The grade of neodymium magnets is generally measured in units millions of Gauss Oersted (MGOe). A magnet of grade N42 has a Maximum Energy Product of 42 MGOe. Generally speaking, the higher the grade, the stronger the magnet.

Tesla's don't convert to MGOe. Apples to oranges.

http://en.wikipedia.org/wiki/Oersted

http://en.wikipedia.org/wiki/Tesla_(unit)

[rlange3]

nevermind, just realized i need a slip ring, and yours is stationary, so you don't need one, you even stated that. My bad.

[sspence]

Ours is not stationary, we just manually unwind the cable on occasion.

[rlange3]

how do you keep the wires that go down the pipe from becoming twisted as the tail makes the generator spin?

[sspence]

the tail rarely goes round and round, more back and forth. If you see the wires getting twisted, just untwist them manually. Otherwise, you need slip rings, which was beyond the diy focus of this project.

[otuaga]

thanks..

[otuaga]

It is part of my question, what voltage should I make the battery bank in order to both use the 48V turbine and run the 144V motor?

[sspence]

All 3 have to match. Unless you can get a 120vac motor, then that can run off a 48v inverter.

[otuaga]

motor voltage = 144V
battery bank = 48V
do you mean that I can wire the wind turbine to the battery bank directly?

[sspence]

Yes, if it's a 48 volt wind turbine. You put a dump load controller on the battery bank that enables a resistive load when the batteries are fully charged. How do you expect to run a 144v motor on a 48 volt battery bank?

[otuaga]

Maybe you can help me with my situation. I want to install a 1kw wind turbine solely for the purpose of running a 90hp DC motor, my main problem is that they both
each require different types of controllers. How can I wire the wind turbine through its controller to charge the batteries and at the same time wire the motor through its controller to draw power from the same battery bank?

[sspence]

what voltage is your motor? what voltage is your battery bank? the wind turbines does not have a controller.

[acarroll3]

How did the performance of the turbine that you built compare to the expected performance?

[sspence]

It met expectations. We knew it would, since there are calculations that will determine what output will be at specific wind speeds. See
http://green-trust.org/windpowercalc/

[acarroll3]

Hi Sspence,

Did you do any sort of wind potential audit before beginning to design and build this turbine? If so could you point me in the direction of the software or other method that you used?

[sspence]

I installed a cheap AIR 303 wind turbine (<$400) and ran that for several years, logging the wind data.

[rborba1]

We’ve come a long way since the early days of electric power but the principle has remained exactly the same, all you have to do is spin a wheel.
The spinning wheel is the heart of every power system in the planet.
With that in mind, I thought of something simple.
Let’s say we drop 64.2lbs from 100 feet high with a line attached to a spin wheel, depending on the set up that wheel would spin many times.
Now comes the simple idea, first how do we lift those 64.2lbs back up there? A little bit of air.
Just one cubic foot of air can lift up to 64.2lbs of dead weight in fresh water.
Now rain or shine, day and night we can produce electricity.
My name is Richard Borba, I’m looking for someone who can help me turn this idea into reality, I’m sure it’s a really bright idea to produce electricity without causing any harm to ourselves and our planet.
Email me at [e-mail]

[naught101]

Every power system on the planet except for those driven by photovoltaics, piezoelectricity, pyroelectricity, etc.

[sspence]

You might think that, but you need to do a little research.

[Palomarbob]

A small 2 blade 16" ~ 17" diameter hxwt will out produce any vxwt by 5x
Use rc motor from a hobby store 20v ~ 30v; 1a ~ 2a; 2000rpm ~ 3000rpm
18ah battery do not charge above 11 watts with diode or diodes
1" ~ 2" tip chord @ 4 ~ 5 deg ( 2" ~ 3" chord at 50% radius @ 11 ~ 12 deg)
airfoil goe188 ( flat side faces wind ) very easy to make

[sspence]

1. This is not a VAWT, it is a HAWT.
2. This unit spins at 650 rpm
3. you aren't going to get 1000 watts with a rc motor

[laiskasmariui]

Hi, How did you determine which wire gauge to use?
1000W / 12V = 83.3A
from any of the ampacity tables i could find online 83 Amps would need arround AWG 4 for enclosed wire and AWG 7 for open air application. Am I missing something? Please explain.

[sspence]

Ampacity tables do not take into affect length of the wire. Each coil , plus each phase carries 1/3 of the current. 35 turns of 2-in-hand 14awg equals 11awg. Each turn is about 6" of wire, so it's about 17' of wire. This equates to a 8% voltage drop at maximum power. If you want to drop to 3%, you could try dual 9awg, but that would be hard to wrap.

[laiskasmariui]

Thanks for the response :) I didn't realize that the three phases share the current.

[sanjay_lim]

I agree with laiskasmariui , don't think more than 200watts at 12 volt is possible from the above setup is produced.

[sspence]

You think wrong.

[rborba1]

I did it and I patented as well, just don't have equipment to get it done

[sspence]

You never will.

[Capo118]

Is this enough wattage for a home? If not what would be a good average wattage amount

[sspence]

Depends on the home, and how much wind you get. with 6 hours of good wind, this unit might produce 4.8 kWh's daily. The typical home uses 30 kWh or so. My off grid home used 10 kWh's daily. I produced over 8 kWh's with solar.

[NickChaney]

Hey, very interesting stuff. What was the total cost of the whole thing?

[sspence]

Somewhere in the neighborhood of $1500 or so in today's dollars.

[TheStudio7]

This is one awesome instructable. THANK YOU.

[twighahn]

i need the diagram dummied down

[sspence]

Here is a great explanation of the coil wiring - http://www.instructables.com/id/WIRING-THE-COILS-IN-3-PHASES-AXIAL-FLUX-GENERATORS/


Also read http://www.windenergy.nl/website/files/artikelen/AXIAL_FLUX_HowItWorks.pdf for more info.