When most people think of wind turbines they think of the most common form which is the horizontal axis wind turbine (HAWT). Today I’ll be introducing you to a design that is radically different and these devices are known as “vertical axis wind turbines”.
First let’s talk about the differences between these two designs. In a typical horizontally oriented design the rotor blades are situated perpendicular to the direction of the wind and the shaft of the motor is parallel to the wind. In a vertical axis wind turbine (VAWT), the blades are vertical or parallel with the pole or tower that the turbine is mounted on.
Some Advantages of Vertical Wind Turbines
- More of these types of turbines can be installed on the same amount of land because as the wind passes through them not as much turbulence is created.
- Due to the orientation of these devices, the entire shaft or pole can turn which makes it possible to mount the actual generator and other mechanisms at ground level. This makes the job of performing maintenance much easier.
- VAWT’s don’t have to point into the wind to start up.
- Devices of this design are more durable than horizontally oriented units. Because they don’t have to point into the wind, they don’t require a tail section to keep the rotor blade assembly pointing windward. During gusty wind conditions, these units are less likely to sustain damage than traditionally designed units.
- They don’t need as much wind to generate power which means they can be installed closer to the ground.
- The vertical orientation of the blades often results in these devices being quieter than standard turbines.
- Since tall towers aren’t necessary, installation and maintenance costs are reduced.
Some Disadvantages of the Vertical Wind Generator Design
- While this design is less likely to be damaged by gusty wind conditions, they are more likely to stall out and stop spinning.
- These types of turbines aren’t typically well suited for use in areas of high wind speeds.
- Due to the vertically oriented blade design, the blades tend to flex and twist as the rotor assembly spins faster and faster. The centrifugal force generated by the spinning blades has been reported to cause stress and fatigue on some blade designs that occasionally results in them breaking.
VAWT Wind Turbine Video
Here’s a short video made by a UK based company that manufactures a VAWT called the “quietrevolution qr5”.