Difference Between Horizontal and Vertical Axis Wind Turbine
Comparison Between Horizontal and Vertical Axis Wind Turbine
The Major Difference Between Horizontal and Vertical Axis Wind Turbine is that In the Vertical Axis Wind Turbine rotation of blades is Vertical and In Horizontal Axis Wind Turbine rotation of blades is Horizontal. The usual images of turbines with three blades spinning is a Horizontal Axis Wind Turbine.
|Horizontal Axis Wind Turbine
|Vertical Axis Wind Turbine
|Axis of rotation is parallel to the air stream
|Axis of rotation is perpendicular to the air stream.
|Yaw control mechanism is required to adjust the rotor around a vertical axis to keep it facing the wind.
|No orientation of rotor is required; these turbines can generate power with the wind coming from any direction.
|The heavy nacelle containing the gearbox, generator, etc. is mounted at the top of the tower, thus the design and installation is complex.
|The nacelle is not required because the gearbox, generator, etc., are located at the ground, thus the design and installation are simple.
|The power coefficient and tip speed ratio are high.
|The power coefficient and tip speed ratio are considerably low.
Horizontal Axis Wind Turbine (HAWT)
- Horizontal axis machines have emerged as the most successful type of turbines. These are being used for commercial energy generation in many parts of the world.
- They have low cut-in wind speed, easy furling and, in general, show a high power coefficient.
- However, their design is more complex and expensive as the generator and gearbox are to be placed at the top of the tower. Also, a tailor yaw drive is to be installed to orient them in the wind direction.
- Main components:
- Turbine blades
- Power transmission system
- Yaw control
Vertical Axis Wind Turbine (VAWT)
- Vertical axis wind turbine (VAWT) is also known as cross-wind axis machines.
- In these machines, the axis of rotation is perpendicular to the direction of the wind.
- The main advantages of a VAWT compared to HAWT are
- The vertical axis wind turbine receives wind from any direction, and hence the yawing system is not required.
- The generator, gearbox, etc. can be installed at the bottom of the tower, hence their tower design and installation is simple.
- Inspection and maintenance is easier.
- They are lighter in weight and cheaper in cost.
- VAWTs are generally not self-starting and have a low power coefficient, these are the major disadvantages. They require a mechanism to start from the stationary position. Additionally, there is a possibility of running the blades at a very high speed and causing damage to the system.
- Main components:
- Rotor shaft or Tower
- Support structure