- Have you seen those long wing structures in plains? Have you ever wondered what is it and for what it is used for?
Why are we discussing the topic?
We all know about the renewable and non-renewable natural energy resources. We have consumed the non-renewable resources at such a rate that now our Earth’s budget for serving us such resources is reduced. So now what can be the potential substitute?
Obviously, renewable energy sources are the alternatives. Wind energy being one of the alternate sources and also it is a clean energy.
Wind energy is one of the fastest growing technologies and is being used by several countries like Spain, China, United States etc.
Do you know wind energy is being used for more than two thousand years? Yes, wind energy has been utilized by the Netherlands for a long time. Definitely, windmills and wind energy are the saviours for the Netherlands.
How do the winds generate?
There are two reasons for the winds to generate. One is the change in atmospheric pressure and other is the Coriolis Effect. There is a difference in atmospheric pressure at the equator and poles. Thus, winds try to escape the region of high pressure and move towards the low pressure region.
Coriolis Effect is termed after Gaspard Gustave de Coriolis, the French engineer. He was the first person to calculate the effect in 1835. The Coriolis Effect causes the moving objects on earth to follow curved paths. In the Northern Hemisphere, the moving object will follow right to the deliberated path and in the Southern Hemisphere, the moving object will follow the left path.
The motion due to Coriolis Effect in the Northern Hemisphere is known as cyclonic flow whereas the motion in the Southern Hemisphere is known as anti-cyclonic flow.
How is wind energy produced?
The uneven heating of the Earth by the Sun drives winds. The winds get modified by the rotation of Earth and the Coriolis Effect. Winds can be applied for running the turbines. The turbines will ultimately transform the kinetic energy into mechanical energy.
Now, there are two possible ways to use the generated mechanical energy. If the mechanical energy is used directly, it is applied for drainage systems. If the mechanical energy is transformed into electrical energy by the generators, it is applied for electricity generation.
Where is wind energy used the most?
Windmills are not like solar energy which is present everywhere. It requires certain situations. Windmills are placed where the wind blows constantly.
At such places wind farms are constructed. Such wind farms consist of hundreds of large turbine mounted tall towers. Gansu wind farm is the largest wind farm in the world.
Such a facility is also available on the offshore region and on shore region. Offshore wind farms and offshore wind turbines can be used.
Denmark generates the highest proportion of wind energy. In 2015, the country was able to generate 42% of its power by wind. It is a big percentage, isn’t it!
Types of turbines
There are two types of turbines, Horizontal axis wind turbines and vertical axis wind turbine.
Horizontal axis wind turbines
These are the turbines we have a picture in our mind of. The one with three blades, of light colour and big height.
Horizontal axis wind turbines are the commonest types of turbines. It has a horizontal shaft. The turbine along with the generator is mounted on a tall tower.
Also some wind sensors may be present. Such wind sensors maintain the axis of the turbine in the wind direction.
Vertical axis wind turbines
Vertical axis wind turbines have vertical shafts. Such turbines are useful where the wind directions are quite fluctuating.
Most commonly such turbines are placed on the roof tops. They do not require much height such as horizontal axis wind turbines.
However, both types of turbines have their benefits. For bulk production of wind energy it is always advisable to use horizontal axis wind turbines. For small production, vertical axis wind turbines are preferred and also their maintenance cost is slightly low.
What are the uses of wind energy?
- One of the most common uses of wind energy is generation of electricity by mounting a turbine with it. Generators are utilized for the conversion of mechanical energy into electricity.
- Wind energy is also utilized by the sailors from ancient times. By using the wind energy, the consumption of fuel can be reduced and the clear-cut destination can be reached.
- Wind energy is earlier utilized for the pulverizing of grains. However, nowadays with the advanced technologies such mechanisms are not in use.
- Wind energy is used in pumping the water.
Accidents in wind plants
Accidents are not very common in the wind industry but there have been several cases. The chances are not as high as natural gas and oil industries. Lets see one such incident.
In Australia, in a wind farm of about 112 turbines when one of them caught fire it has disconnected the power of about 63,000 houses. The fire was so intense that it spread over 80,000 hectares of a national park. The cause of such a devastating fire was an electrical failure.
Lightning is the most significant reason for the fires. Overheating can be another cause. Highly inflammable materials are present which are more susceptible to catch the fire.
Topography and wind project
The direction, velocity and duration of wind varies locally as well as on a regional scale. Topography of the area plays a significant role in this. Wind velocity often increases over hill tops or mountains. The increase in wind velocity is the contribution of vertical convergence of wind and partly by horizontal convergence as well.
Thus the topography of the area becomes a significant factor in deciding about the establishment of wind projects. Also there are some geographical and meteorological problems too that need to be taken into considerations.
Wind energy advantages
- The first and foremost advantage is its availability. The wind energy is available free of cost.
- It is a renewable energy resource and thus it is an alternative for the conventional energy sources.
- It is a pollution free energy resource and so it is clean energy.
- Wind energy is cost effective. Land based utility scale wind is one of the lowest priced energy sources.
- Also from an economical point of view, wind energy is important. It creates employment in the nation. According to some surveys, wind turbine technician is the fastest growing American job.
- The source is abundant and inexhaustible.
- It is a variant of Solar energy and so it is sustainable.
- It reduces our dependency on conventional sources such as oil and natural gas.
Disadvantages of wind energy
- The cost is similar to that of conventional energy sources. However, much advancement has reduced the cost.
- Most of the wind farms are located away from remote areas, thus transmission power lines are required.
- The turbines create lots of noise which is not suitable for humans.’
- The set up requires a large area for the proper functioning, particularly the horizontal axis wind turbines.
- Sometimes such establishments can also become life threatening for birds. Birds get injured due to the blades of windmills.
- Windmills may cause interference with radio and television broadcasts.
- Also can degrade the scenic resources of an area.
Like every thing has two sides of the coin, same is the case with wind energy. It has its own pros and cons. Wind energy may not be able to solve our all the problems today but we never know advancement in technology can make the alternate, a principal source.
At Least for now we can rely on the fact that wind energy is a pollution free and clean energy resource. It has low impacts on the environment and now we have to think of our Earth first instead of us.