Steve’s Wind Turbine and How He Made It

Thanks to Kevin and Tom for your help!

Kihei Workshop on wind and solar May 23, 2009. Click this link for slide show.

Hi and welcome to my do-it-yourself wind turbine webpage. I’ll show you some photos and try to explain how and why I made the wind turbine. We live on an organic homestead on Maui and have no power, except for what we make. We have 300 watts of solar power, but that means that we get about 100 watts for 6-8 hours daily. In the summer, it is enough, but in the winter we need a little more. So I made this wind turbine.

I used 1/2 inch rope as guy wires. I plan to put in steel ones sometime. The rope does hold the pole steady. The pole is tilted downward to face the rising wind.

The wind turbine generates up to 5.25 amps into the battery bank. We are getting about 48 amp hours a day from solar cells. Wind is variable, but lately we have been getting about 32 amp hours from this wind turbine. We are getting almost as much from our $200 wind turbine as from our $1200 solar panels. Sometimes the sun shines and sometimes the wind blows.

Below are photos and details of how I made the wind turbine. The photos are to enjoy, the details may help others build similar generators.

The long Piece on the top is a 4 foot piece of the metal track that is used for metal studs in buildings. I also have a 1 foot piece of the metal stud which fits inside. This makes a perfect nest for the generator when it is held with 3 hose clamps. On the left is the flange and pipe nipple (1 1/4 inch). On the right is a piece of plywood screwed and glued onto a 1 by 2 board. These parts I got at Home Depot very cheaply.

The motor-looking thing is an Ametek 30 volt dc motor/generator. I got this from a computer salvage company on the Internet for $20. This seems to be the right choice for my 12 volt system. The little round thing is a bushing I found at MaGuire Bearing (SH x 5/8 SFGP, Sure-Grip Bushing by TB Wood’s). The bushing mounts on the shaft of the generator with set screws. I decided to shorten the bushing and drill an extra set screw hole. The three-armed arbor mounts onto this bushing and also slides onto the shaft of the generator - very secure. I used red Locktight on all of these threads so they would not rattle off.

Since these parts are steel, with some parts galvanized, I primed them with an oil-based primer and painted them with a good oil-based enamel. I used all stainless steel bolts and nuts because we have salt wind here on Maui.

This thing is called a yaw mount because it allows the blades and generator to follow the wind. I have a 1 inch galvanized water pipe that slides nicely into this 1 1/4 water pipe nipple. On top of the 1 inch pipe (not shown) is a stainless washer that slides against the plastic just above the flange. This is a 1/4 inch thick piece of polypropylene that I found. This is the bearing for turning. The chain limits the turning to 180 degrees either way and also keeps the top from coming off. I used a Cyclone fence clamp for the clamp.

Here you can see the generator mounted on the support with three hose clamps. You can also see the way that the arbor is mounted onto the bushing on the generator shaft. I put blobs of silicone II on top of the set screw holes to keep rust out. The silicone will come out with pliers. The blades are painted brown and are on the left.

Here I am showing the assembled yaw mount. The blades are one of the most expensive parts of the wind turbine. I got them on ebay for $85. I got them from Terry@tlgwindpower.com. They are aluminum, very light and make almost no sound when turning. They are hands-down the quietest blades I have heard. They are 3 foot diameter when assembled. You can see the tail screwed and bolted onto the yaw mount.

Waterproofing is vital. I used a Tupperware top (the red part) for a seal. I drilled it out to fit snugly onto the 5/8 inch generator shaft. It is a rubbery plastic. I put an inner and an outer ring of silicone II under the red plastic to seal out the weather. The stainless steel fender washers help, too.

You can also see how the hose clamps pull the generator right down to the bottom of the metal stud channel.

Here we see the yaw mount from the top. There is a hole in the top for the wires to go into and then through the pipe. I used two layers of shrink wrap and lots of electrical tape around the wires. I also used silicone sealent here.

I put a base pole into the ground. I buried a 10 foot long fence pole (1 1/2 inch) 4 feet deep with a post-hole digger. You can see it vertical to the left. I drilled two holes for two 3/8 high-strength bolts. The one at the top is a pivot and the one at the bottom secures the longer pole vertically. On the left you can see how I work on the wind turbine. I can pivot it up and down alone and put in the other bolt.

This puts the wind turbine about 16 feet above the ground - it seems enough.

We tested the generator by hooking it up to a car battery and running it with different drill motors. We also tested open circuit voltage and short-circuited amperage.

In the chart below, RPM is the speed of rotation. V is volts going into a car battery at 12.62 v. A is the amps going into the car battery. Power w shows how many watts are being generated. Open voltage and shorted amps gave unrealistic numbers.

We were including a diode and fuse in the circuit.   Diode Info: Schottky Diode, VSK4030, 40v30a, bolt is output, 0.5v drop (my tested actual drop is 0.9ohm), $2 ea w/ship. 562 423 4879 David.

Rpm

V

A

Power w

 

V open

A shorted

300

13.4

0.22

3

 

12.2

2.5

500

13.5

1.15

15.5

 

20

3.7

800

13.78

2.9

40

 

30

4.4

1000

15.5

3.7

57

 

41

5.8

1200

15

4.4

66

 

46

6.4

Here we used a hole hog drill and a variac to adjust the voltage and speed of the drill. Yes, that is a piece of hose with hose clamps coupling the drill bit to the generator shaft. It dampens load and couples effectively.

The final puzzle was running the power down the hill about 400 feet. I considered inverting the voltage to 120 and using a battery charger to reduce transmission loss. When I tested battery chargers I found out that they lose 35% to 50% of the power.

I decided to run the power in DC form. I bought a reel of 1000 feet 12AWG romex. I ran one romex with all three wires together for plus and one for minus. This is the equivalent of about 7.5AWG and enough to keep power losses down to about 10%. The resistance through the wire, there and back, is only 0.4 ohms.

If you would like to contact me, you may email windpower@naturalhealthwizards.com