When building a wind generator it's very important to match the size of your motor with your blades. This will result in a wind generator that is more efficient which will produce more power. Let's take a look at how to match motor size to the size of your blades.

If you haven't already you should have calculated how much power your wind generator will produce with the size of blades that you've chosen. If you haven't check out How much power do you want your wind generator to produce.

If using PVC blades you're limited to a blade diameter of around 6' (8' if you feel daring and don't mind if a blade snaps). Since this is quite a small wind generator you're going to need a smallish motor. One important factor in small wind generators is to make sure your motor doesn't cog. For a description of what cogging is visit: wind generator motor cogging. A couple good motors for a small wind generator are the Ametek (38V - 60V models) and recently I found another motor by a company called Hathaway. The best one I've found from Hathaway is their 48V model. It produces 12 volts at very low RPM's and there is no cogging.

For wind generators under 8' diameter you can use either the Ametek or the Hathaway motors. In general as the motor is a permanent magnet DC motor, has little or no cogging and the diameter of the motor is less than 5" it's a perfect fit.

What if your wind generator is bigger than 8'? Well, we need to step up to a bigger motor. The next 'step' in blade size ranges from 8' to roughly 16'. If you need a wind generator with a blade diameter bigger than 16' I hope it's not for home use (unless you're charging an electric car I guess). For these bigger blade sizes we need a motor that can withstand the terrific forces that it's going to be subjected to. We're also going to need a motor that can kick out a bunch more power. Enter a company called Windblue.

Windblue is a terrific company that makes a quality product. They have a line of DC motors which are perfect for blade sizes between 8' and 16'. These motors are a lot more rugged than the Ametek and can take quite a punishment without failing. They also produce a ton of power. The bigger model can produce 3Kw - 5Kw.

When building your wind generator remember that you need to 'match' your motor size to the size of your blades. A small diameter wind generator should have a motor whose diameter is less than 4.5" and has little or no cogging. A large wind generator needs a bigger motor so it can withstand the force of the wind (and produce more power). If you have any questions just leave a comment.

If you would like to learn more about building a wind generator just click here