Wind turbine, wind energy, or wind power are explained along with basic details, types, various applications, advantages, disadvantages etc.
Let’s try to understand wind turbine, wind energy, or wind power. The need of the hour is to move the energy and power requirements to renewable sources. This is where the Wind energy or wind power used in the wind turbine comes into play.
Let’s get into,
The wind is created by nature due to many reasons,
Wind energy or wind power is defined as the energy that uses wind to creates electricity. As wind occurs naturally in the earth’s atmosphere, it is a renewable source of energy.
Wind Power is calculated based on the following equation,
P = (1/2) ρAV3
There are few characteristics of wind energy,
The wind turbine is one kind of turbine, which is placed in specific places to generate power, mainly to generate electricity, running small scale plants as an alternative power source.
There are some methods used to counter the use of fossil fuels. Renewable sources of energy like solar, tidal, hydro, geothermal, biomass are considered as a alternative.
One of them is Wind energy. So, to generate energy from the wind, the Wind turbine is a necessity.
There are mainly two types of turbine used one horizontal axis and other is the vertical axis. The classification of the wind turbine is not that much bigger, let’s get into it.
Wind turbines are classified based two criteria,
So, this is the small classifications of the wind turbines. There are various parts associated with the wind turbines that accommodates its working. Before knowing more about the horizontal axis turbine and vertical axis turbine let’s know more about its components.
The major components of the wind turbines are tower, rotor, nacelle, generator and the base or foundation of the wind turbine.
These are general and major components of the wind turbines,
The foundation or the base of wind turbine is the one on which these turbines are placed. The different methods are employed for the offshore and onshore turbine placements.
Now for the offshore wind turbines, the foundation or base is constructed underwater. It cannot be seen but also it is built with a strong structure to hold the forces and mass weight of the wind turbine.
Nowadays most modern turbines tower is round tubular steel with a diameter of 3-4 meter (10-14 feet).
Generally, it has a height of 75-110 meters (250-370 feet).
The rotor is the one which accommodates the blades on periphery.
The hub holds the turbine blades. The blades are attached to the hub, the hub allows the blades to rotate.
The blades are hollow and are made of composite material that light and strong.
The nacelle houses the generator of the wind turbines.
The gearbox is present in the nacelle it is a major component of wind turbines. The work of the gearbox is it will increase the main shaft speed of approximately 12-25 RPM to the speed required for the generator. That is the reason for calling the generator side shaft the high-speed shaft.
The wind can change its direction and the wind turbine should adjust according to the direction and adjust its orientations. The rotation is known as the yaw motion, the nacelle and the rotor revolve about the tower axis.
Brake is an important part of a wind turbine, in case it needs to be stopped the rotation of the turbine blades, due to the following reasons,
Wind turbine brake is placed in associated with low-speed shaft and it can be electrical or mechanical or hydraulic types depending on the applications.
The generator is the component which converts the mechanical energy received from the rotor to electrical energy. It has same kind of structure as the electric motor.
There are various sensors in wind turbines, like,
Wind direction is not fixed, it can be changed based on the season. Hence, it is required t change the facing of the rotor.
Now all these are the basic components of the wind turbines. Now let’s know more about the horizontal and vertical axis turbines in brief.
The horizontal axis wind turbines are widely used turbines nowadays. They produce the majority of power in today’s world.
HAWT blades are made stiff it prevents the blades from being pushed into the tower and sometimes they tilt forward into the wind by a small amount of margin.
Other features like controlling mechanisms, breaks are used to avoid damages to the wind turbine.
The vertical axis wind turbines have their rotor shaft arranged vertically. The vertical arrangement has one advantage of no need of pointing the turbine into the wind for the effectiveness.
Apart from the above advantages, there are some disadvantages like VAWT have low rotational speeds, higher torque which costs higher for the drive train.
The rotation of the aerofoil is 360 degrees within the wind flow there will be high dynamic loading on the blades. Vertical axis wind turbines have difficulties installing on the tower hence they are mounted on rooftops or ground.
Obviously, there will be less wind speed so the energy generated will be lower.
There are some subtypes of the vertical axis wind turbine they are as follows.
They are also known as the egg-beater designs. They are named after the French inventor George Darrieus. These wind turbines require external power support to start turning.
Also, they have good efficiency but because of the large torque ripple and cyclic stresses on the tower, it results in poor reliability.
This one is subtype of Darrieus wind turbines but it has straight opposed to curved blades. The Giromill have the feature of variable pitch for reducing the torque pulsation and also it is self-starting.
There are some advantages like high starting torque, a higher coefficient of performance.
The savonius are drag type devices with two more scoops that are used in the anemometers. They are self-starting and have at least three scoops.
The modified version of savonius wind turbine has long helical scoops and provides smooth torque.
These are all the advantages of the HAWT and VAWT turbines. Wind turbines are one of the renewable sources of electricity-producing device. There are numerous advantages of the same with few disadvantages.
Let’s see the advantages and disadvantages of wind energy developed by the wind turbines.
There are so many wind turbines across the globe.
Let’s try to understand how does wind turbine work in step by step.
Step#1 Wind Energy
The wind is flowing towards the turbine blades and it has kinetic energy. The turbine blade or hub can be adjusted with respect to the wind direction.
Due to the wind force, a lift force & drag forces are acting on the blades. Blade starts rotating due to the resultant force.
Step#2 Rotation of Rotor
Turbine blades are attached to the rotor and as the turbine blades start to rotate, the rotor will also rotate accordingly.
Step#3 Rotation of Low-Speed Shaft
The rotor is connected to a drive shaft, called a low-speed shaft. It also rotates with the rotor but the speed will less.
Step#4 Increase of turbine speed
There is a gearbox inside the nacelle where the low-speed shaft is connected to a high-speed shaft through a gear mechanism. The speed is increased here due to the high-speed ratio in the gearbox.
High speed-shaft is connected to a generator and rotation of the shaft creates a magnetic field within the generator.
Step#6 Power Transmission
The electricity is transferred to a power grid from the generator through power cables. Power cables run within the turbine tower.
Due to this magnetic effect, electricity is produced from mechanical energy. This electricity is connected to the power grid for further consumption.
There are many sensors to adjust the turbine direction with respect to the wind direction. The yaw mechanism helps to rotate the turbine.
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There is a controller to controls as well as to stop the turbine in case the wind speed is beyond design or there is any fault. Basically, the controller helps the wind turbine to keep it safe.
Cost effective power production
The power generated by the wind turbines is cost effective. It costs about 1-2 cents per kilowatt hour of power usage after the tax credits. Another reason is the electricity generated from the wind farms is at fixed prices and doesn’t depend on other factors like on fossil fuels in case of other power generation plants.
Reliable and infinite renewable energy
The wind power is the renewable energy source. The wind power doesn’t use any fossil fuels in needs the one-time investment and long-term returns are better considering the low environmental impacts.
The wind power being a renewable power source is environment friendly. It doesn’t need any fossil fuel to power up its components. The power generation depends on the winds.
Availability in remote areas
The one-time investment can be useful for the remote areas to provide the electricity. The areas where the normal power distribution is poor the wind power can act as a saviour in remote areas,
The wind energy is free and can be used efficiently with modern technology.
The main disadvantages of wind energy are as follows,
These are all the advantages and disadvantages of the wind energy produced by wind turbines.
We have already calculated wind energy, however, we will see the actual wind power from the wind turbine.
The wind power of wind turbine is expressed, as below,
P = (1/2) ρAV3x G.E x B.E
A wind turbine has a rotor of diameter 50m, it rotates at 12m/s. Calculate the wind power, if air density is 1.2 kg/m3, generator efficiency 72%, bearing efficiency 81%.
Wind power P =?
P = (1/2) ρAV3x G.E x B.E
P = (1/2) x 1.2 x 1962.5 x 123 x 0.72 x 0.81
P = 1186648.0 watt
P = 1186.6 kW.
Wind power is sustainable energy and the technology is simple, however, there are few key areas that need to study prior to set-up a wind turbine project,
The installation of the wind turbine is a very simple process, and the steps are as follows,
There are several wind turbines across the world, few of them are listed,
Wind energy, as well as a wind turbine, is now being used by lots of countries also keeping in mind environmental effects. Wind energy will help to reduce the dependence on fossil fuels for power generation
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