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.

Comments

[Blunt_Zephyr]

I've found http://www.otherpower.com/ a decent-resource on "off-grid living".

[Eric T]

Do you send the power down tower as AC then convert to DC? How close are your coils to the magnents? Does your PDF file have the Plans for the Steel plates? If plastic was used to hold the magnents would that alow the lines of flux to get to the coils better? Please send the PDF to [e-mail]

[sspence]

Yes, it's 3 phase ac down to the batteries, where the 3 phase rectifier converts it to dc. the coils are about 1/4" from the magnets. I do not have plans for the steel plates, but they are just 12" rounds.. Plastic would not complete the lines of flux, needs to be ferrous. PDF of this instrucatble sent. More info available at http://www.green-trust.org/products/

[Eric T]

Thanks.

[Bob174]

I could not find any discussion on connecting the coils for 3 phase power output, and for connecting the rectifying diodes (how many are needed?). I could not find any information on actual performance (watts at say 10 mph wind speed,

[sspence]

there are 9 coils, 3 phases of 3 in series. every third coil is connected in series. the diode bridge is a 3 phase bridge, just like a car alternator. read hugh piggots book, or dan fink's.

[zihanjj]

 will it be simple to use a Car Alternator, but ofcourse an additional power should goto the Field coils of the Alternator, but it reduce the weight of the Generator and give's you more control. Also a cut-off if the wind speed is way too high. 

[sspence]

 Car alternators make lousy wind turbines and are not, and should not be used. Not just the field coil issue, like you mentioned, but also rpm range is all wrong.

[thirtyfivefox]

Unless you live in an area that generates 250+ mph winds steadily and use REALLY short blades ;-)

[pfred2]

or a gear box.

[sspence]

gear boxes are inefficient.

[J-Ri]

There is a difference between energy efficiency and time/money efficiency. Turning gears robs power (due to friction) which, in low wind conditions, is better put to charging the battery bank. If it takes and extra week to build everything yourself, it's going to generate the same power when all is said and done.

[J-Ri]

There are a number of factors to consider. While you are correct that huge blades would allow you to gear it up and spin an alternator faster, there are other things to consider. First, you need to mount the turbine higher. A larger tower is therefore needed, which means much more material and possible renting/hiring a crane or other lifting equipment. Second, in high wind, how are you going to stop those blades from over-spinning and ripping off? Third, when all is said and done, you have a much, much higher cost machine. One could likely build several smaller turbines with higher total output for the cost of one that could safely work as you suggest. Fourth, maintenance. Aside from greasing the bearings, I doubt the author's design requires any. What about all the moving parts and wear parts that would be needed for your idea? I know they are implemented in the multi-million dollar commercial sized ones, but you can't compare those to something like this.

[sspence]

There's little enough power in the wind, why waste it in a gear box. Please stop commenting on my instructable. You do not understand wind turbine design.

[zigzagchris]

Nice, most people dont realize the watt/price of windmills vs solar panels is greater

[valiox]

Because I don't have enough money to buy big Neodymium magnets,I have a big question> What if I am using N50 type, but wich will be 9mm in diameter, and 5 mm height, and I will reduce the number of turns for every coil, so in that case I will increase the number of the magnets, and the number of the coils?

[sspence]

With that many changes, all I can say is have fun experimenting.

[zilcho]

Could a car alternator be used? A large belt drive could be used to gear up the alternator which would probably require higher speed rpm

[sspence]

It would suck for a few reasons.
1. the gearing robs power
2. the field coils rob power
3. not designed for high power long term output
4. only about 60% efficient turning rotary motion into electrical energy.

[bchurchman]

Hello!
What wind speed is needed to generate 1 kW? Thanks!

[sspence]

30 mph.

[SWA_Flyer]

What is the rotor RPM at that wind speed?

[sspence]

about 650 rpm

[SWA_Flyer]

I know there needs to be a N-S attraction between plates. Just curious to know if you have all N facing on one plate and all S facing on the other or if the magnet alternate Thanks

[sspence]

the faces alternate, N-S-N-S, etc.

[bchurchman]

Gotta love a fellow tinkerer! Was looking at your other projects. What's a good weekend project without the Fire Department involved? LOL

[sspence]

The only time I had to call the fire department was when I was burning grass, and it got away from me. Embarrassing, as I was a member .....

[jtorres24]

hey i had been looking for this kind of proyect, and i would like to add the fact that you can build the alternator saving at least 1/4 the cost. also, you can build the blades, they can be made of pvc (Wind turbine pipe blade design) i have a basic idea of the wind turbine i was wondering if you can mail me the PDF, i believe it would have a good performance given the speed of the wind in Concepcion, Chile :D

thanks and nice DIY.

-. Juan

[sspence]

The "fact" that you are adding is the point and already outlined in this instructable. It's all DIY, from the alternator, to the blades, (we used wood), to the tower. You can get the pdf and much more at www.green-trust.org/products/

[rambob]

Hello Spence,

I love your work.

Going to build your Stator and put it on a 55 gallon plastic VAWT set up. It will be a 12v system.

During my research, months ago, I saw places that you could buy pre-wound copper coils. Now I can't find them.

Do you know of any place that I could buy your suggested wire set up already wound?

Thanks!

Rambob

[sspence]

I'm not aware of any prebuilt coils, but it's one of the easiest parts of the turbine to build. They will be very different from the HAWT coils, as your rpm range may be different, and you may need more turns or more coils.

[paumavallyed]

[e-mail],I had some trouble downloading the complete DIY 1000 watt wind turbine building process, my computer has some issues. I may have missed the finished product.
Question: In the first picture. It shows the man installing a few final parts. Do the electronics have a nose cone to deflect water, or what would protect these electronics. Do they need protection from the elements ? This is an amazing creation !
Very functional.

[sspence]

 There's no electronics (rectifier and charge controller) at the turbine, they stay indoors in the battery room. No nose cone necessary.

[danlong]

Hi guy, Should have done this last year when I first found it as I see wire has jumped and the price of the magnets almost triple as with just about any parts "alternative energy". (there's only a buck or two difference between the drilled and not drilled magnets).


So you are saying you pump AC to the house then condition it? What about ramping the the output voltage to 620VAC for transmission to reduce losses. I need to build a 130 foot tower because I'm in the woods in a valley, then another 200 feet to the house.


Also, I assume from the photo that your turbine is fixed directional. Any hints on omni-directional. I was considering a vertical turbine because our "prevailing" winds in Wisconsin, in this valley, could be any direction for days. But the vertical turbine, along with lack of efficiency, is noisy.

Thanks, Dan

[sspence]

the turbine is not fixed directional. It rotates with wind direction. I have no simple way to ramp up the voltage, as it varies in both voltage and frequency. A 48v turbine would work well for that distance.

[danlong]

One question.

What is the separation between the coil and the magnet face? I didn't see a stat on the field spread. I did note that the magnet has a 175 F max temp before damage and I have visions of a 100F plus day with the turbine cranking. How do the magnets stay "cooler" along with the coils themselves during power production?

[sspence]

It's between 1/8" and 1/4". The closer you can get it without touching, the more power you make. This is an open "air cooled" design. The magnets are spinning in the wind acting like little fan blades. Where do you get the 175F number? Neo's have a curie point of 310 to 400 C.

[jferguson11]

Does the size of the magnet matter or is it the grade that matters more? or is it a combination of the two? Thanks for your time :)

[sspence]

combination of the two. the size of the magnet dictates the size of the coil, which increases voltage as the coil gets longer, larger. the power of the magnet allows more current flow as you get higher in ratings.

[marandp]

Sorry, I meant 3/4" thick!