Horizontal Wind Turbines

The more traditional wind turbine seen at wind farms and with large megawatt wind farms.

• 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. In contrast, all vertical axis wind turbines, and most proposed airborne wind turbine designs, involve various types of reciprocating actions, requiring airfoil surfaces to backtrack against the wind for part of the cycle. Backtracking against the wind leads to inherently lower efficiency.
• The face of a horizontal axis blade is struck by the wind at a consistent angle regardless of the position in its rotation. This results in a consistent lateral wind loading over the course of a rotation, reducing vibration and audible noise coupled to the tower or mount.

Vertical Wind Turbines

An alternative choice for customers in urban areas or areas that need a lower profile system that has many advantages.

• A massive tower structure is less frequently used, as VAWTs are more frequently mounted with the lower bearing mounted near the ground.
• Designs without yaw mechanisms are possible with fixed pitch rotor designs.
• The generator of a VAWT can be located nearer the ground, making it easier to maintain the moving parts.
• VAWTs have lower wind startup speeds than HAWTs. Typically, they start creating electricity at 6 m.p.h. (10 km/h).
• VAWTs may be built at locations where taller structures are prohibited.
• VAWTs situated close to the ground can take advantage of locations where mesas, hilltops, ridgelines, and passes funnel the wind and increase wind velocity.
• VAWTs may have a lower noise signature.