This is annual average wind speed measured 50 meters above the ground or sea.
| meters per second | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.0 | 1.3 | 2.7 | 3.5 | 4.5 | 5.0 | 5.5 | 6.0 | 6.5 | 7.0 | 7.5 | 8.0 | 8.5 | 9.0 | >12.0 |
| 0.0 | 2.9 | 6.0 | 7.8 | 10.0 | 11.2 | 12.3 | 13.4 | 14.5 | 15.7 | 16.8 | 17.9 | 19.0 | 20.1 | >26.8 |
| miles per hour | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Wind Speed Map of the World
Source: World Climate Maps
How to make a Stator - Rewiring
TheBackShed.com - F&P Re-Wire: "F&P Stator Rewiring
From factory the Fisher & Paykel stator is wired into one large star winding, producing 3 phase AC when used as a generator*. If we were to use this on our windmill the output voltage would range from 0 to 300 volts unloaded, and up to 2-3 amps maximum loaded, not a very usable range for charging batteries.
The standard stators have either a string of 14 or 12 poles for each phase. 3 phases, means 42 or 36 poles total, depending on what model stator you have. We are going to rewire the stator into shorter strings to reduce the voltage, and then connect these strings in parallel to increase the current.
* Technically its an ALTERNATOR, but the term GENERATOR is more commonly used.
There are 2 F&P Smartdrive combinations commonly used for our windmill alternators, the old 42 pole stator, and the new 36 pole stator."
From factory the Fisher & Paykel stator is wired into one large star winding, producing 3 phase AC when used as a generator*. If we were to use this on our windmill the output voltage would range from 0 to 300 volts unloaded, and up to 2-3 amps maximum loaded, not a very usable range for charging batteries.
The standard stators have either a string of 14 or 12 poles for each phase. 3 phases, means 42 or 36 poles total, depending on what model stator you have. We are going to rewire the stator into shorter strings to reduce the voltage, and then connect these strings in parallel to increase the current.
* Technically its an ALTERNATOR, but the term GENERATOR is more commonly used.
There are 2 F&P Smartdrive combinations commonly used for our windmill alternators, the old 42 pole stator, and the new 36 pole stator."
Profile of a Windmil Blade
The profile of a well designed windmill blade resembles a aircraft wind, giving lift on the trailing edge. The blade has a angle of attack to the wind to give its best lift, and this lift drives the blade forward. There also needs to be a slight twist along the length of the blade, the blade tip is traveling much faster than the part of the blade closest to the center of the propeller, so the blade needs to be tilted to give the same angle of attack.
You also need to consider tip speed, or TSR (Tip Speed Ratio). The tips of the windmill blade travel much faster than the wind speed, so a TSR of 7 means the tips travel at 7 times the wind speed. A typical 2 meter diameter turbine at 500rpm could have a tip speed of over 200kmh, and any airborne dust or unfortunate insects will be very abrasive at this speed. For windmill blades made from a soft material, such as timber, a layer of wear resistant aluminum tape or fiberglass is usually applied to the leading edge.
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