How to Build an Alternator Wind Generator

A wind generator can be made at home using a car alternator.

Wind generators use the power of the wind to rotate blades, with a generator or motor converting this rotation into electricity. They are becoming increasingly common in large scale power generation and for smaller projects such as powering an individual home. Car alternators can be used as a motor within a wind generator system to convert the rotation of the blades into electrical energy. This energy can then be stored in a battery until needed.

Things You'll Need

• PVC pipe
• Metal disk
• Metal rod
• Cogs, 1 large, 1 small
• 2 pieces of two-by-four
• Alternator
• Rectangular piece of plastic or metal
• Pipe bracket
• Pipe
• Large piece of wood
• Battery

Instructions

1. 

   The blades for the wind generator can be made using PVC piping.

   Construct the blades for the wind generator using polyvinyl chloride (PVC) piping. To make four blades, take a length of pipe, similar to those used in guttering, and cut it into quarters along lengthwise. Then take each of these sections and cut them diagonally from corner to corner to make triangular blades. A good length for a small wind generator is around 18 to 20 inches, with the pipe being 20 percent as thick to make the blades strong enough.

2. Attach these blades, equally spaced, to a round disc of metal using bolts or screws. Drill a hole in the middle of the disc and fit a metal pole into it, making sure that it is a tight fit so the pole will rotate when the blades do. To the other end of the pole, attach a large cog; this can be much larger than the metal disc.

3. Take a piece of two-by-four, slightly longer in length than the diameter of the large cog. Drill a hole through the middle of the two-by-four, large enough for the pole to sit in and still move freely. Fit washers to the pole on either side of this wood to prevent the blades from sliding toward or away from the wood.

4. Take another length of two-by-four, this time around a yard in length. Screw the first piece of two-by-four on top of this piece at one end, so they are at right angles to each other. Just behind this, attach the alternator. To the head of the alternator, connect a small cog that will be turned by the larger one; this will enable the head of the alternator to be turned several times for every rotation of the blades. Cover the alternator and the cogs with plastic sheeting to protect them from the weather.

5. Screw a rectangular piece of plastic or metal to the other end of the long piece of two-by-four. This will act as a "tail," pivoting the blades into the most efficient orientation for the direction of the wind.

6. Behind the alternator, drill a hole large enough to pass the wires through. Underneath this hole, on the other side of the wood, fix a pipe bracket. Slot a slightly smaller pipe into this bracket; a slightly smaller pipe will allow the head of the wind generator to pivot freely. Run the wires from the alternator down this pipe.

7. Make a base for the wind generator with a large, heavy piece of wood, ideally attached with screws or bolts to the surface it is sitting on for additional stability. Fix the bottom of the pipe securely to the base; it shouldn't be able to pivot at this end.

8. Run the wires from the alternator from the bottom of the pipe to the battery. Connect the positive and negative wires to the correct electrodes on the battery. House the battery in a weatherproof structure, such as a shed.

Tips & Warnings

• As an alternative to cogs, a large wheel (for example a bicycle wheel without the tire) can be used. Run a belt around the wheel and also around the alternator head. This will produce the same effect as two different-sized cogs, as every time the wheel turns as a result of the blades rotating, the alternator head will turn several times.

References

• Rowand: Alternator and Generator Theory
• Michael Davis: How I Home-built an Electricity Producing Wind Turbine
• Your Green Dream: Quick PVC Wind Turbine/ Windmill Blades