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The amount of power that can be extracted from the wind relates directly to two basic items, the swept diameter of the blades and the wind speed. Too much blade for your generator can be as much of a problem as too little. If you research windmill blades, you will come across the acronym, TSR, this stands for Tip Speed Ratio. This is theoretically how much faster the blade tip is traveling in ratio to the actual wind speed. |
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So what do you need to harness some of that "free" energy from the wind? 1. A tower or supported mast to get your machine up in the wind. 2. A generator. 3. A set of blades and a tail (or properly called "vane") 4. Some good wire. 5. A battery bank or something to use the collected energy.This project can be as simple or complex as you would like to make it. Yes, I did leave out several things, like a blocking diode, charge controller, shunt load, boost capacitor, and meters, but I will talk about those as we go. |
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One way to get started is to use a permanent magnet motor as a generator. Surplus computer tape drive motors (old reel to reel units) are quite popular. These are typically well built continuous duty units. A search on eBay for "Ametek" or "wind generator" will find several listings. Depending on the motor, the shaft could be 1/2" or 5/8" in diameter. You will need a "motor arbor" like the one pictured to connect your motor/generator to the hub for the blades. I found mine at the local "Ace" hardware store. When I started these were selling for $15.00 now they list for $150.00. That is one reason to look at a F&P motor. |
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Again, there are many different windmill blades on the market that can be simply bought and mounted on your motor/generator. I've now tried several, and the ones pictured here seem to be the best for the buck. I had a set of these spin off the end of my Ametek unit, (make sure that motor arbor is secure to the shaft!!) and pinwheel from 33 feet up and land in the dirt with only a bent hub. Close to being unbreakable. |
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Here is a link to instructions to a good mast erection. It just might give you some good ideas. http://www.bergey.com/Products/XL1.Tilt.IM.4.pdf |
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Here we go. Pictured at the left is a diode. This acts as a one way valve. They come in many shapes and sizes. To charge a battery, you need to produce more voltage than the battery, so you can push energy back into it. As long as your generator is spinning fast enough this is possible. However when the wind slows down, this motor/generator becomes a motor and will be powered by the battery if there is not a blocking diode in the circuit. |
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Its a little hard to see here but pictured at the left is the circuit that I've used for my windmill. I went ahead and linked it to a bigger image. Please click on the picture. NOTE!! Make sure that you use a fuse! FUSES are Important! |
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