Wind turbines are devices used to convert wind energy into electricity, and they come in different shapes, sizes, and types. Horizontal axis and Vertical-axis wind turbines (VAWT) are the commonly available types. The Vertical Axis Wind Turbine, used for residential purposes, serves as an excellent source of renewable energy for homes.
Working and Components of Vertical-Axis Wind Turbine (VAWT)
Vertical-axis wind turbines work by utilizing vertically oriented blades that rotate around a central vertical shaft, harnessing the power of the wind. The rotor, driven by the wind, sets the generator in motion, transforming mechanical energy into electrical power.
The main components of a vertical axis wind turbine include the bearing, blade & blade support, frame, and shaft.
Applications of a Vertical Axis Wind Turbine
The following are some of its applications.
- Ideal for small-scale wind projects and residential applications
- They are preferably used in places with frequent storms or strong winds due to their durability.
- These turbines are capable of generating power even in unstable weather conditions such as gusty winds and turbulence.
Types of Vertical-Axis Wind Turbine (VAWT)
There are two types of vertical axis wind turbines available: the Darrieus Wind Turbine and the Savonius Wind Turbine.
1. Darrieus Wind Turbine
The Darrieus wind turbine was named after the renowned French inventor, Georges Darrieus, and it is also called an egg-beater. The turbines are equipped with long, curved wings that are connected to the top and base of the rotor shaft at each end. The aerodynamic force of the lift is used to revolve these turbines.
The wind turbine harnesses the power of the wind by creating a suction effect on its front face, causing the wings to spin. Savonius turbines have low drag because of their wing shape. Once the revolution commences, these turbines will accelerate to rotate at a velocity surpassing that of the wind.
2. Savonius Wind Turbine
Its blades are positioned in a helix shape around a vertical shaft. The main principle behind these turbines is to utilize flow resistance to activate the rotors. This means that the dynamic force of the wind against the turbine blades propels the rotor into motion.
The solid wind-receiving area is one of the most remarkable characteristics of this turbine. Simultaneously, the reverse side of the blades meets an aerodynamic resistance force.
For example, when we run or cycle, we feel the rush of the airflow in the opposite direction, this is the same with these turbines.
Similarly, when this is applied to these wind turbines, they are able to rotate rapidly, resembling the speed of the wind.
Read in detail about the 2 types of vertical axis wind turbine
Advantages and Disadvantages of VAWT
There are several advantages to using a vertical-axis wind turbine (VAWT):
- Safe, scalable, and they can generate power in any wind direction.
- Cost-effective, easy-to-install-operate, and portable.
- No need for a tall tower, as the gearbox, generator, and other parts are placed on the ground.
- Fewer speed blades pose less danger to people and birds.
- Works effectively in different weather conditions.
- Can be used where taller structures are restricted.
- No mechanisms are required to operate these turbines.
- Economical, efficient, and quiet residential energy sources for urban areas.
There are several drawbacks associated with a vertical axis wind turbine.
- Efficiency decreases in HAWTs due to blade drag during rotation.
- Difficult to stack on towers due to being connected to bases like buildings or ground.
- Lower rotational efficiency and reduce wind speed.
- Components are susceptible to wear and tear sooner than other types of wind turbines.
- Animals may disrupt rotation in open areas.
- Turbulent flow near the ground creates high vibrations and noise pollution.
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