Starting a 1.8kW wind turbine project

MKHPhillips · #1 02-06-2010, 05:13 AM

I purchased a 200 volt DC motor (permanent magnet, 15" long by 7" around, 85 pounds, 1 3/8 diameter shaft, 2 3/4 long, 1800 watts, 10.5 amps) from eBay for $61. 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 three 60 watt solar panels for the camper but we are not getting enough sun (Rochester, NY) to keep the batteries charged.

MKHPhillips · #2 02-07-2010, 03:12 AM

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

**Desert Rat** · #3 02-07-2010, 04:56 AM

Welcome to the forum MKHPhillips, glad you joined us.

Keep us posted, we are very interested.

**myocardia** · #4 02-08-2010, 10:57 PM

Quote:

Originally Posted by MKHPhillips

Plus, I will need your help.

Hi, welcome to Nature2Energy. What exactly are you wanting/needing help with? The few things we know about wind turbines are: 1) if your tower doesn't cost at least 2.5-3x as much as your turbine (including the blades), then it isn't even worth erecting and 2) never try to make your own blades-- even most of the blades you can buy are close to worthless 3) the blades and the tower really the only important parts of a wind turbine.

If you're wanting to use this motor, you really have no choice other than paying a machine shop somewhere to drill a hole and cut threads into that hole (called "tapping"). Every hub you can buy requires having a threaded hole to mount the hub.

Quote:

I’m thinking about 6 feet long for each blade.

That is about twice as long as you need. Six foot long blades will give you a swept area of ~20 feet, and that will drive a 3,000 watt turbine. You've only got a 150-170 watt turbine. See, power = voltage x amperage. With you having bought only a ~10A motor, you multiply that times your voltage (which is ~15-17V, when charging two 6V batteries, or one 12V battery), and you end up with somewhere between 150 & 170 watts. When "shopping" for permanent magnet motors to use for wind turbines, the perfect motor is high amperage, and roughly twice the voltage as the batteries you'll be charging.

Quote:

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

For most small wind turbines, 45 feet is an absolute minimum, with 60 feet being the recommended minimum. With as little as your turbine will be producing, you may not want to spend the money for a 45 foot tower. I can tell you this much, though: it won't produce much less power laying flat on the ground than it will on a less than 30 foot tower. Good luck, and let us know what you end up doing.

MKHPhillips · #5 02-14-2010, 11:33 AM

I finalized the hub and created blades (out of 2x4's) yesterday. I balanced the blades and tested them in the wind using a large nail in the center. Today or next weekend, I will put the blades on the hub.

MKHPhillips · #6 02-14-2010, 11:38 AM

Here are some more pics.

MKHPhillips · #7 02-14-2010, 11:41 AM

and some more pics.

MKHPhillips · #8 02-14-2010, 06:07 PM

Well, I could not wait until next weekend to test it. I mounted the hub and attached it to the generator. Since I did not have a pole setup yet, I used my backhoe and turned it into a mobile wind turbine. Pointed into the 15-20 MPH wind, I generated over 20 volts with no load. I quickly became discouraged with I hooked a load to it. I used a 12 volt headlight from a car. The blades quickly came to a stall. I’m not sure if this is what will happen when I connect it to a battery. If it is, then I will have to have larger & wider blades.

MKHPhillips · #9 02-14-2010, 06:08 PM

Here are some more pics.

**Desert Rat** · #10 02-14-2010, 10:11 PM

Looks good so far, I wonder if you need just a little more wind to power the headlight you tested? How many watts is the head light?

Do you think PVC blades being lighter would help?

I am really enjoying this keep us posted