Different types of wind turbines

Note: This article was written by Kush Gulati

In the era of impending threat from climate change, and the exigency of needing to switch to cleaner and renewable resources, it is clear that wind power will play a crucial role in the future. There are 2 primary types of wind turbines, Horizontal Axis Wind Turbines (HAWTs) and Vertical Axis Wind Turbines ( VAWTs). They both have their places in the coming decades when switching to renewable energy.

Starting with vertical axis wind turbines, there are several different types of them, including:

• Darrieus Turbines –These have curved, airfoil-shaped blades and rely on aerodynamic lift to generate power.

• Savonius Turbines – These use drag forces and have a cup or S-shape, making them less efficient but effective in low-wind conditions.

• Hybrid Designs – Some designs combine both lift- and drag-based mechanisms for improved efficiency.

Advantages of VAWTs:

• It’s ability to be used with wind coming in any direction

• Easier to Maintain (Since Gearbox is at the bottom).

• More compact and potentially quieter than HAWTs

• Suitable for urban and offshore applications

Disadvantages:

• Less efficient than HAWTs due to lower rotational speeds

• Higher mechanical stress on components

• Some designs struggle with self-starting and require an initial push or external power source

Horizontal axis wind turbines, are more efficient and common. They rotate around a horizontal axis like a traditional windmill and are mounted higher to capture higher and more consistent wind.

Types of Horizontal axis wind turbines:

• Upwind Turbines – The rotor faces the wind, reducing turbulence from the tower but requires a yaw system to adjust direction.

• Downwind Turbines – The rotor is placed behind the tower, allowing it to passively align with the wind, but it experiences turbulence from the tower itself.

Advantages of HAWTs:

• More efficient than VAWTs due to greater wind capture and lift-based design.

• Widely used and extensively optimized for energy production.

• Can be built at large scales, with offshore models reaching capacities of 10+ MW.

• Tall towers allow access to steadier and stronger winds, increasing energy output.

Disadvantages of HAWTs:

• Requires active adjustment to face the wind.

• High wind speeds can cause stress on blades and the tower.

• Large towers require specialized equipment and infrastructure.

• Can be loud and visually intrusive in certain locations.

In conclusion, certain types of wind turbines are better in different scenarios. VAWTs are better in urban areas and/or areas with inconsistent wind direction. HAWTs are better in large wind farms and offshore where wind speed and direction is consistent.