Conventional Sources of Energy
Conventional sources of energy are the energy that is naturally available in nature. They are present in a minimal amount in the world, and will one day perish if it is not sustainably used. Natural gas, coal, oil, thermal power plants, hydroelectricity, and hydropower plants are some of the examples of conventional sources of energy. Among these sources, hydroelectricity is considered to be clean and an efficient source of energy for long term use.
The most significant disadvantage of conventional sources of energy is that they tend to pollute the environment. They are also very limited and finite in terms of quantity available for extraction. The only exception is hydroelectricity. India has a high potential to produce electricity with hydropower plants. Only 15% of the total open source is being used right now. Therefore, you need to get a proper grasp on what is hydroelectricity and on what is hydropower plant.
Hydroelectricity
Let's start by answering the question of what is hydroelectricity. When electrical current is generated from the kinetic energy of flowing water, we call it hydroelectricity. It could be a water turbine driven electric generator in a dam, a generator driven by a water wheel in a water stream, or even an air-driven electric generator in which air is compressed to drive the generator by the action of ocean waves.
Advantages of Hydroelectricity:
It is a clean and non-polluting source of energy.
No fuel is required. Water is the source of energy, and it does not consume water.
Dams are constructed near rivers. As the water level rises, the kinetic energy of water gets changed to potential energy.
Disadvantages of Hydroelectricity:
Highly expensive.
Large areas of human habitation and agricultural fields are submerged.
Dams can be made in limited areas.
Uses of Hydroelectricity:
To generate and supply clean energy.
Hydroelectricity is stored during low usage and used when demand increases.
Hydropower Plant
Let's try to understand what is hydropower plant. When water is at a height, it has potential energy stored in it. When this water flows down, its potential energy is first converted to kinetic energy and then to mechanical energy with the help of turbines. With the use of a generator, the mechanical energy is transformed into electrical energy. Hydropower is essential only next to thermal power. Hydropower plants meet nearly 20% of the total power of the world.
Advantages of Hydropower Plants:
Rainwater is stored in the dam. Thus, it is considered to be a renewable source of energy.
The construction of dams helps in providing irrigation of the local farmers; it also helps in controlling floods.
This method of electricity generation does not produce any pollution.
Their operational cost is very low.
The Disadvantage of Hydropower Plants:
Hydropower plants require high capital with a low rate of return.
Dams can only be built at specific locations.
A Large area of agriculture is submerged underwater.
Uses of Hydropower Plants:
Since the generation of electricity in hydropower plants is very quick, they can provide essential back-up power during major electricity outages.
Hydropower is used to control flood, help in irrigation, and water supply.
Hydropower plays a major role in reducing greenhouse gas emissions.
Working Principle of Hydropower Plant
Now that you have a thorough understanding of what is hydroelectricity, and on what is hydropower plant, we will soon see how is hydroelectricity produced in the plants. We use the gravitational force of the water to produce electricity.
(Image will be Uploaded soon)
The first thing that we need is a high-rise dam to stop the flow of water and accumulate it in one place. When all the water is gathered, a lot of potential energy is stored in the water. Next, the sluice gates are opened up, and the water is made to flow with high pressure. When water flows, the potential energy gets converted into kinetic energy. When the running water hits the blades of a turbine, the kinetic energy of the water is converted into mechanical energy. This turbine is in turn connected to a generator. As the turbine rotates rapidly, the generator generates electricity in the powerhouse. The used water will flow out into the river, and the water level in the dam decreases. This level will increase once again with the help of natural rainwater. Therefore, it is a natural resource that will never get exhausted.
World Distribution of Hydropower
The most crucial and widely used renewable source of energy is hydroelectricity which is produced in hydropower plants. Hydropower plants meet only 20% of the total power of the world. When it comes to the production of hydroelectricity, China is the largest producer, followed by the United States, Brazil, and Canada. Around 66% of the economically feasible hydropower is yet to be tapped. Untapped resources are still present in Central Africa, China, India, and Latin America.
Hydropower remains the dominant electricity source across North and Central America.
South America was the second-fastest-growing region, adding 4,855 MW in installed hydropower capacity in 2018.
Hydropower is increasingly recognised in Europe for its flexible services to maintain secure, affordable and sustainable energy supply
East Asia and the Pacific again saw the highest annual increase in hydropower installed capacity in 2018.
FAQs on Hydroelectricity and Hydropower Plant
1. What are the different types of hydropower plants?
Pumped Storage: Utilisation of the flow of water from a reservoir at the upper reservoir to one at the lower reservoir employed in this way of pumped-up storage. They do not produce net energy but act as an energy buffer. Combined with steam power stations, it reduces the power load fluctuations to narrower limits. In certain cases, the storage plant comprises pump and motor with no turbines. It increases the head in the feeder reservoir of a separate hydro-electric plant while the motor improves the power factor in the electric supply network.
Cascaded/Series Power Plant: It uses a series of canals to produce energy.
Tidal Power Plant: The tides are used for the generation of power plants. Although it is not a hydropower plant, the discharge and head are made available due to the tide caused by the rotation of the earth. Among the main advantages of this type of power plant is that it compensates for the failure of hydropower plants and also improves the efficiency of the power generation system. It is also cheaper than thermal and hydropower plants and provides constant energy supply.
Run-of River: A small and micro hydro power plant that utilises water that runs off a river without affecting the environment.
2. In a hydroelectric power plant, what kind of energy transformation takes place?
There are three transformations. Firstly, potential energy (due to the height of the water in the reservoir) changes to kinetic energy (the energy from the water falling a distance). Then kinetic energy of the water is converted to mechanical energy in the turbine. The turbine is coupled to a generator which converts this energy into electrical energy. The electrical energy again goes through various transmissions before reaching different places like homes of the people. The functioning of both hydroelectric and coal power plants is similar where a power source is used to turn a turbine which then turns a metal shaft in an electric generator which produces electricity. The only difference is that coal-fired power plants use steam to turn the power blades and hydroelectric plants use falling water on the turbine. For a more detailed overview, students can follow Vedantu.
3. What is the difference between Micro and Large Hydropower plants?
Based on the size of the Hydropower plants, they can be divided into two types:
Micro Hydropower Plants - These are run-of river plants which help in agro processing, local lighting, bringing water to the field, etc. Some major advantages are low maintenance costs, no impact on the environment, low distribution costs, etc. As compared to the large hydropower plants, the construction and integration into local environments of Small Hydropower projects takes less time and effort. This is the reason why these small hydropower projects have been increasing globally, especially in rural and semi-urban areas where electricity is not easily available or other energy sources are not economically attractive.
Large Hydropower Plants- These plants included large dams and huge water storage reservoirs which are now at a decline. Due to the huge investment costs and requirement of massive acres of land, it has led to loss of the environment.
4. What are the advantages of Hydroelectric energy?
There are many advantages of Hydroelectric energy. They are:
It is a non-polluting energy which is clean and has less impact on the environment as compared to the other forms of energy.
It does not utilize water but helps produce energy through it.
There is no use of fuel.
It can help meet peak energy demand and also is renewable in nature.
The emissions due to decomposition of residue within the reservoir is far less than fossil fuels and hence is harmless.
Hydropower is renewable and will not run out unless the water stops flowing. There are many pieces of equipment around the world which are still functioning after more than 3 decades.
It is the most reliable source of energy which unlike solar energy or wind energy is available 24/7 and is constant.
5. What are the advantages of Hydropower Plants?
Some of the major advantages of a Hydropower Plant are:
Power plants are very flexible as the energy, in the beginning, utilised by the power stations is very less. It all depends on the use of a turbine. It is so reliable that it can adjust the flow of water. Either the plant is allowed to increase or decrease the production of energy as per the requirement.
Water brings in massive amounts of energy. When it is dropped from an elevated height, it transforms into gravitational potential energy. A single power plant can bring electricity to millions of homes.
Small Hydropower plants can be used for irrigation of fields and other small agro processing activities. Dams like the Hoover dam and other hydropower projects have also created lakes for recreation purposes and also drawing tourists.
Hydropower plants also avoid flooding and can be handled precisely.
These hydropower projects also help in the faster development of towns and villages due to the requirement of resources for the project.
