2 Blade Advantages
- Variable blade pitch, which gives the turbine blades the optimum angle of attack. Allowing the angle of attack to be remotely adjusted gives greater control, so the turbine collects the maximum amount of wind energy for the time of day and season.
- The tall tower base allows access to stronger wind in sites with wind shear. In some wind shear sites, every ten meters up, the wind speed can increase by 20% and the power output by 34%.
- High efficiency, since the blades always move perpendicularly to the wind, receiving power through the whole rotation.
- Variable pitch control is simplified and lightened when only 2 blades are used.
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3 Blade Disadvantages
- The tall towers and 3 blades up to 90 meters long are difficult to transport. Transportation can now cost 20% of equipment costs.
- 3 blade units are more difficult to install, needing taller and heavier capacity cranes.
- Massive tower construction is required to support all 3 heavy blades, larger gearbox, and generator.
- Reflections from tall 3 blade units may affect side lobes of radar installations creating signal clutter, although filtering can suppress it.
- Require a large (heavier) yaw control mechanism to turn the 3 blades toward the wind.
- 3 blade units have more parts, are heavier and less economical than 2 blade units.
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