While less common than their horizontal-axis counterparts, Vertical Axis Wind Turbines (VAWTs) offer four distinct advantages, particularly in specific environments.
Here are the four main advantages of vertical axis wind turbines:
1. Omnidirectional: They Accept Wind from Any Direction
A VAWT's most significant advantage is that it does not need to be pointed into the wind. The vertical alignment of the blades allows it to capture wind from any direction.
- Resulting Benefit: This eliminates the need for a complex and expensive yaw mechanism, which is the system that turns a traditional horizontal turbine to face the wind. This simplification reduces manufacturing costs, potential points of failure, and energy lost during yaw adjustments, making VAWTs ideal for locations with turbulent or frequently shifting wind directions, such as urban areas.
2. Easier Maintenance and Installation
The major components of a VAWT—the gearbox and generator—are located at the base of the structure, near the ground.
- Resulting Benefit: This makes installation and routine maintenance significantly easier, safer, and less expensive. Technicians do not need to work hundreds of feet in the air, and heavy cranes are not required for servicing the drivetrain. This accessibility drastically lowers long-term operational costs.
3. Lower Noise and Visual Impact
VAWTs generally operate at lower rotational speeds than horizontal axis turbines.
- Resulting Benefit: The lower tip-speed ratio reduces the aerodynamic "swoosh" noise, making them much quieter. Their slower rotation and compact, vertical design are also often considered less visually intrusive. These qualities make them more suitable for installation in residential or urban areas where noise and aesthetic impact are major concerns.
4. Better Performance in Turbulent Conditions and Higher Land Efficiency
Because they are not dependent on a stable wind direction, VAWTs perform well in the chaotic and gusty wind conditions often found near the ground or around buildings.
- Resulting Benefit: This makes them effective for urban and small-scale generation. Furthermore, research has shown that VAWTs can be placed much closer together in a wind farm. Unlike horizontal turbines, which create a long wake of turbulence behind them, closely spaced VAWTs can have a synergistic effect, with the turbulence from one turbine potentially increasing the efficiency of the next. This allows for a much higher power output per unit of land.
