There are a number of types of wind generators. Hours of research and testing have been done on virtually every possible concept with the sole objective of producing the maximum amount of power for the lowest cost at the highest possible reliability.
The most common designs include:
- Horizontal upwind: The generator shaft is positioned horizontally and the wind hits the blade before the tower.
- Horizontal downwind: The generator shaft is positioned horizontally and the wind hits the tower first then the blade.
- Vertical Axis: The generator shaft is positioned vertically with the blades pointing up with the generator mounted on the ground or a short tower.
There are two basic types of airfoils (blades) a lifting and drag type.
- The drag style airfoil is typically what you see with an old Dutch wind mill or American water pumping wind mill. The blades are generally a flat plat which the wind hits and causes to rotate. This type of design is great for very low wind areas and will develop a lot of torque to perform an operation. However, in medium to higher winds, their capabilities to produce energy are limited.
The lifting style airfoil is what you see in most modern wind turbines and on airplanes. A properly designed airfoil is capable of converting significantly more power in medium and higher winds. Actually, with this design, the fewer number of blades the more efficient this design can be. Two European companies actually produced one bladed machines however, dynamic balance issues prevented them from becoming a commercial success. |
