What is Vertical Axis Wind Turbine : Working & Its Applications

Day by day, pollution levels and sea levels have been increased. So, renewable energy sources around the world have been increasing to reduce energy costs and protect the world. To overcome this, wind turbines are designed to generate electrical energy. A wind turbine is an electrical device that converts the energy from the wind into electricity. These turbines are available in different types, sizes, and shapes. So the types of wind turbines are horizontal-axis wind turbine & vertical axis wind turbine. This article discusses an overview of one of the types of wind turbine namely vertical axis wind turbine or VAWT.

What is Vertical Axis Wind Turbine or VAWT?

The Vertical Axis Wind Turbine is a type of wind turbine and it is most frequently used for residential purposes to provide a renewable energy source to the home. This turbine includes the rotor shaft and two or three blades where the rotor shaft moves vertically. So, this turbine movement is related to the spinning of coins on the edge. In this turbine, the generator is placed at the bottom of the tower whereas the blades are covered around the shaft.

The vertical axis wind turbine working principle is that, the rotors in the turbine revolve around a vertical shaft by using vertically oriented blades. So they generate electricity by using wind power. The wind operates the rotor which is connected to the generator, so the generator converts the energy from mechanical to electrical. Vertical axis wind turbine components are blade, shaft, bearing, frame & blade support.

Vertical Axis Wind Turbine Block Diagram

The block diagram of a vertical axis wind turbine is shown below. The output energy generated from this can be used by any type of load. Here, the automatic lighting system is used as a load. This block diagram includes a Vertical Axis Wind Turbine (VAWT), gearbox, generator, battery, LDR circuit and LED.

Vertical Axis Wind Turbine

The type of Vertical Axis Wind Turbine used in this system is savories VAWT.

Gear Box

A gearbox in a wind turbine is mainly used to enhance the rotating speed from a low sped shaft to a high-speed shaft connecting through an electrical generator. Gears within the gearbox of a wind turbine are subjected to severe cyclic loading because of uneven wind loads that are stochastic within the environment.

Generator

The generator in the wind turbine converts the energy from mechanical to electrical. These generators are a bit strange as compared to generators used in electrical grids.

Rechargeable Battery

The output electric energy generated by the generator will be stored in the rechargeable battery of the wind turbine.

LDR Circuit

The LDR circuit is used to turn ON/OFF the light.

Vertical Axis Wind Turbine Working

This turbine works once the wind turns the turbine. Here, the savory VAWT is used in this lighting system. Once this turbine rotates, then the generator will get it as mechanical input & generate the output as electrical energy.

This turbine is arranged on the dividers of the highway roads. The shape of turbine wings is curved to get the wind for revolution from the 2-way road where the vehicle speed will make this turbine turn. Here, wind speed is used in different ways based on our requirements.

A vertical axis wind turbine is connected to the Gearbox which includes gears. This gearbox is directly connected to the electric generator shaft. This turbine will revolve once the wind blows & the gearbox in this system will enhance the turbine rotations internally & send these rotations to the generator like a mechanical input.  So the generator will generate the output as the electrical energy by using this input so that this output will be stored within the rechargeable battery.

In this way, electricity is generated and stored in the battery using the vehicle’s speed with the help of a turbine. The stored energy is used for the automatic lighting system. The LDR circuit uses a resistor, LDR (Light Dependent Resistor), transistor, battery, and LED (Light Emitting Diode).

The transistor collector terminal is connected to the LED’s negative terminal whereas the emitter is connected to the GND. Here, the resistor terminals are connected directly to the voltage source whereas the negative is connected to the LDR.

When the LDR circuit is connected directly to the battery, then the LDR will start detecting the light. So when the intensity of light is decreased then LED will be activated automatically. So this LDR circuit is applicable in automatic ON or OFF light systems. When the light intensity of the Sun is decreased in the dusk then LDR will detect the light & supply the LED.

Vertical Axis Wind Turbine Types

The vertical axis wind turbines are available in two types like Savonius Wind Turbine & Darrieus Wind Turbine.

Savonius Wind Turbine

Savonius wind turbine includes the blades which are arranged around the vertical shaft within a helix form. One of the most significant features of this turbine is the solid wind-receiving area. These turbines mainly rely on the mechanism of flow resistance to make the rotors active which means, the dynamic force of the wind against the turbine blades thrust the rotor into revolution.

Simultaneously, the reverse side of the blades meets an aerodynamic resistance force. This is like when running or cycling, we experience the airflow coming opposite to us. Because of this, these turbines can simply turn fast like the wind speed. Please refer to this link to know more about Savonius Wind Turbine.

Darrieus Wind Turbine

Darrieus wind turbine name is taken from the French inventor namely; Georges Darrieus. It is also called an egg-beater. These turbines include curved & long wings where each end of these wings is connected to the top & base of the rotor shaft.

These types of wind turbines use the aerodynamic force of the lift to revolve. By flowing around the construction, the wind will create suction on the front face of the wind turbine to drive the wings to revolve. Like Savonius turbines, these turbines do not experience as much drag due to the shape of wings. Once the revolution begins, these turbines will go faster to rotate faster than the speed of the wind. Please refer to this link to know more about Darrieus Wind Turbine.

Advantages

The advantages of a vertical axis wind turbine include the following.

• Safety for manpower.
• Scalability.
• They can generate electricity in any direction of the wind.
• It doesn’t require a strong supporting tower because the gearbox, generator & other components are arranged on the ground.
• As compared to horizontal axis turbines, these are cheaper to design.
• Installation is easy as compared to other types.
• These are portable so we can simply move from one location to another.
• These are designed with fewer speed blades to reduce the risk to birds & people.
• They work in all weather conditions like variable winds & mountain conditions.
• These are allowable where taller structures are not allowed.
• Its operation is simple so they don’t bother people in residential areas.
• These turbines can be arranged close to the earth so that maintenance, the cost for construction can be reduced.
• To operate these turbines, we don’t require any mechanisms.
• You can use the wind turbine where tall structures are not allowed.
• These are economical, quiet, efficient & ideal for residential energy sources, particularly in urban areas.

Disadvantages

The disadvantages of a vertical axis wind turbine include the following.

• As compared to HAWT, the efficiency level will be decreased because of the drag that happens in the blades when they rotate.
• These are very hard to arrange on towers because they are connected on bases like buildings or ground.
• The efficiency of rotation is low.
• Lower accessible wind speed.
• Component Wear-down.
• Low efficiency.
• Self-Starting mechanism.
• Some animals or birds may interrupt its rotation because it is arranged in an open area.
• They have high vibration due to the flow of air close to the ground makes the turbulent flow
• They produce noise pollution

Applications

The applications of a vertical axis wind turbine include the following.

• Used in small wind projects
• Used in residential applications
• These turbines are used to generate power even in not stable weather conditions like gusty wind & turbulence.

Thus, this is all about an overview of a Vertical axis wind turbine  or VAWT. In this type of wind turbine, the main rotor shaft is arranged vertically so that it captures wind from any direction. These turbines operate without needing yaw controls apart from the direction of the wind. These turbines were innovative designs and they have good features including quiet operation. These are smaller units, so we can easily locate them in commercial and residential areas. Here is a question for you, what is a Horizontal axis wind turbine?