Starting a 1.8kW wind turbine project

[(unknown)]

It was a lot bigger than I thought. I will attempt to build a wind turbine and I want to share the experience with all of you. Plus, I will need your help. After cleaning it up, I hooked my meter to it. With a quick spin by hand, I received up to 30 volts. Therefore, I would not need to have high RPMs to charge my camper batteries (two 6 volts).

I want to follow the plans at http://www.mdpub.com/Wind_Turbine/index.html

Hub:

I will need to get or build a hub. I'm not quite sure how to go about this. The shaft is 1 3/8" in diameter and 2 ¾" long. The shaft does not have any grooves in it and the end does not have a hole for a bolt. I'm thinking about some sort of small cap that will slip over top of the 1 3/8" shaft and then bolt an 8" round piece of steel to it.

Blades:

I also need to figure out the size of the blades in comparison to the generator size. I either want to build them out of PVC pipe or 2x4s. I'm thinking about 6 feet long for each blade. I also need to figure out which way to rotate the motor properly. I think it needs to turn clockwise.

Wires:

There are 6 wires coming from the motor (see pic). The red & white ones are thicker so I assume they are the positive & negative.

Mounting:

I was thinking about mounting it on top of a 2x6 at 5 feet long.

Tower:

I was thinking about 2" diameter piece of steel conduit. Not sure how tall yet.

Charge controller & bridge rectifier:

Don't know yet. I may build or just buy.

I have a feeling this will be quite an adventure. I already built 3 60 watt solar panels for the camper but we are not getting enough sun (Rochester, NY) to keep the batteries charged.

[bob golding]

you are not expecting to get 1800 watts at 30 volts i hope? what speed is it. there is a formula to work out the current at various speeds  but you need the speed to work it out. to get an idea you could put say 24 volts in and measure the speed then try stopping it and checking the  stall current. this should give you some idea.

bob golding

[Janne]

For charging a 12V system, the motor is not a very good choise. Since it is only rated for 10A, you would be able to get about 14V*10A = 140W out of it. Also, as its rated speed is 1000rpm, it would cut in at about 60-70rpm, which is way too slow for any suitable prop size for those kind of power levels.

The motor would work better, if you could have a higher voltage battery bank to feed it into, or if could install a DC-DC converter that would convert the high generator voltage to suit the 12V battery system.. The members running mppt systems between their wind generators and battery banks could propably help better here.

[MKHPhillips]

I'm trying to upload photos but cannot figure it out. The 6 photos are listed when I click "Your Photo Uploads" to the right. But I cannot seem to add them to my posting.

[MKHPhillips]

The motor tag has 1000 RPMs on it. I would show you but I can't seem to attach the pics.

[DanB]

It does look like a beast of motor.

Usually, off the shelf motors like this are not that appropriate for wind energy.  You might get something here...  but as has been pointed out by others, forget about 1800W.

Here are some of the problems that I expect you'll run into.

• it's rated at 10 amps.  Roughly... figure that (maybe a bit more) to be the rating of it as a generator.  So perhaps at best, at 12 Volts, you'll have a 150 Watt generator.

  
  

• it's going to generate 12V at very low rpm...  my guess is around 75 rpm or so, which seems to be confirmed by your hand spin test.  That's a good cutin speed for a very large wind turbine, but the 10 amp rating is well short of what you need for such a big machine.  It would be nice for a 5 or 6' diameter turbine (which is the upper end of what I'd want for a machine rated at 10 amps/12V) if it would cutin (hit 12VDC) at something around 250 rpm.

  
  
  

That said, I suppose if I was going to play with it, I would build a high solidity, slow rotating blade for it.  Perhaps 5 or more blades.

Or... better yet, give up on 12 Volts and try for 24Volts, it'd be a better match and you'd get more power.  Still... it will be quite slow and you'll want to design a low speed rotor for it.

2" conduit is probably not good enough for your tower - I'd make it stronger and be sure to use guy wires and get them up as high as you can (just below the blade tips)

There is a lot more to this... you might read a book on the topic before you get in too deep!

Good luck and keep us posted!

[FishbonzWV]

Hub: If you can find a V belt pulley that size with set screws, then weld a flat plate onto it. The plate with no hole in it will keep the pulley from sliding down the shaft and you can bolt the blades to the plate. I think a pulley that size will be hard to find, most that size use a tapered locking collar.

Speed: Since it has a low cut-in RPM you will probable have to use a 5 blade rotor to get the torque to keep it out of stall. Most likely 4 foot blades.

You don't need a rectifier since it is a DC motor.

Ghurd dump load controller.

Bonz

[DanB]

actually he'll likely want a single rectifier (1 diode) to prevent current flowing from the battery back into the motor.

[ghurd]

You can not go much past the 10.5A of output without risk of burning up the motor,

so it is limited to about 150W in a 12V system.

It would be better suited to a 48V system.  Same 10.5A, but 600W.

That's awful big to work with considering only 150W out.

The tower will be a serious PITA considering what it could be.

The low cut it I think will be quite problematic, even with PVC blades.

The pic showing overall size is to big for board rules,

here is a link to that monster motor,

http://www.fieldlines.com/images/scimages/27033/101_1880.jpg

And the name plate,

G-

[MKHPhillips]

The pictures can be viewed at http://www.wind-sun.com/ForumVB/showthread.php?t=6927

[zap]

It sounds like a candidate for a fun VAWT project!

[FishbonzWV]

Yes,

He will need a blocking diode but not a bridge rectifier as stated.

[Jon Miller]

Or Hydro.

[CmeBREW]

I agree it would make a good VAWT (I like Helix) project at that low cut-in and the limitations on the Amps.  Sounds the same as my alternator on my newest Vawt here: (12v cut-in at about 75rpm)

http://www.youtube.com/watch?v=_FQRz-aAaLs

Only put it up yesterday.  So far only wind from the worst turbulant direction. My house is blocking all the wind!  But it did 80Watts briefly even from that, so I expect around 100watts when better wind direction returns.

About $100 bucks more to weld up the Blade Rotor including the 12 foot long clear Polycarbonate cut in half. (6' long blades// 20 Sq. feet swept area)

-Have fun.

[richhagen]

Just my take,

Actually, it doesn't seem to me like that terrible of a match for a 48V system for an off the shelf DC motor, 10 amp 570 Watt or so max, with a cut in at about 240 rpm, and a 6 foot blade of about tsr 6 or so.  If operating at TSR 6, the blades would cut in at about eight and a half mile per hour wind, but from my observations, blades carved to operate and pull power at a particular TSR will tend to operate at higher actual TSR before cut in although in your case the systems total friction is unknown.  For any reasonable low wind performance you'll need a bit of swept area, and as a result, I don't think you'll match the blades torque to the generators over a very wide range of wind speeds for for relatively fixed voltage battery charging since you will have to limit the current to 10 amps or so (the motors current from the faceplate).  It would need working furling as when the winds increase, the motors power take would be quickly overpowered and the blades would overspeed.  Rich

[MKHPhillips]

I started to build a hub today. When I connected a 12v car battery to it, it turned at 60 RPMs.

[zap]

Looks good... and fun!

What are the sails made of?

It's hard to tell from the video about the balance.  Is it out of balance that much?

Looks like a good bit of snow laying around.

[CmeBREW]

Zap: Sails/Blades made from corrugated Polycarbonate panels at Lowes. (Homedepot has the same thing)  These were made from one 12 foot long (26"W) Panel ($30) that I cut in two with Tin snips easily.  Stuff is really tough. Stepped on it several times--won't break or crack. 100% UV protection both sides - Multiple colors.

I used the clear since it is virtually unnoticable from the road. I just figured out how to 'weight balance' it, so that IS the main problem. Will take down and balance it today. If (and ONLY if) it does decent power this week I will make a video of it producing power and show here.

If the fella with the big heavy Dc motor does make say a 7' diam. (High Solidity 5 or 6 blade) Hawt out of that motor, I would be afraid of the 10amp motor MIGHT not be able to hold back the blades in a 60mph gust with it Electrically shut down,(it would 'let go') and would free-spin which is frightening belive me. And eat up the brushes in quick order and probably ruin the commutator. Unless, perhaps an emergency Disc brake of some sort??  Just ideas.  

[Perry1]

This means you will have to spin it up to about 100 rpm to get 12V out due to inefficiencies in the motor. Still a pretty slow speed though.

Perry

[12AX7]

Hello..

It looks like your motor has brushes, and if so....

Just a few "general' comments.

MKHPhillips said..

" After cleaning it "

Did you take it apart to clean it?  Check the condition of both the brushes and the commutator?  Clean out the carbon dust (from the brushes)?

Did you reinstall the brushes in the same locations and orientation?

If you didn't you may want to do so.   Don't forget to inspect the bearings, (others, please chime in!).

MKHPhillips said..

 "I also need to figure out which way to rotate the motor properly. I think it needs to turn clockwise."

Most all DC motors can run either CW or CCW.  The only concern here would be that if while it was being used did it run CW CCW or both.  If it was used in both directions it shouldn't matter which direction you run it.  The issue at hand is how the brushes seated to the commutator.  With new brushes and a clean commutator direction shouldn't matter.

Also, there is a "common" opinion among motor manufactures that a DC motor (with brushes) should be mounted so that the brushes are "horizontal"  and not vertical.

The reason being that the carbon dust will settle to the bottom and you don't want this conductive dust shorting from a brush to the case.

I'm not sure this is really an issue with the motor used as a wind gen, most manufactures are assuming that the motor will be mounted to a common frame and being driven by some sort of DC drive,  and this mounting practice is more about personal safety and protection for the DC drive.

MKHPhillips said..

"Tower:

I was thinking about 2" diameter piece of steel conduit. Not sure how tall yet."

As already mentioned, this may be a bad idea.  Conduit is pretty soft stuff (it's made to bend).

When much younger and not so bright I used conduit for antenna mast.  I learned real quick how to make pretzels!  

That looks like a beast of a motor, and it's going to need some serious support.

Have fun!

ax7

Mark

[zap]

Thanks for the info CmeBREW... it does look nice and I have a few sheets of that stuff.