Conventional and Non- Conventional Sources of Energy

Introduction:

Sources of energy are classified as conventional and non-conventional sources of energy. In this session, we are going to learn about a few conventional sources and how electricity is harnessed through these energies.

Explanation:

Conventional and Non-conventional Sources of Energy :

Sources of energy are also classified as :

1. Conventional sources of energy
2. Non-conventional sources of energy.

Conventional Sources of Energy :

They are those which are used extensively and meet a marked portion of our energy requirement and these are :

a. Fossil fuels (coal, oil, and natural gas) and

b. Hydro energy (energy of water flowing in rivers).

c. Biomass energy

d. Wind energy

Non-conventional Sources of Energy:

They are those that are not used as extensively as the conventional ones and meet our energy requirements only on a limited scale.

Example:

a. Solar energy

b. Ocean energy (tidal energy, wave energy, ocean thermal energy, OTE),

c. Geothermal energy

d. Nuclear energy

These sources of energy which have been tapped with the aid of advances in technology to meet our growing energy needs are also called alternative sources of energy.

Fossil Fuels :

Fossil fuels are the remains of prehistoric plants and animals that got buried deep inside the early millions of years ago due to some natural processes.

The energy from fossil fuels is in fact, that solar energy which was trapped by natural processes a very long time ago. Coal, petroleum, and natural gas are fossil fuels.

Formation of Fossil Fuels:

During its formation, an entire organism or its parts often get buried in sand or mud. These then decay and disintegrate, leaving no signs of their existence.

In fact, after their death, the harder parts of organisms settle down and are covered by sediments and subjected to extreme pressure and temperature of the earth, converting them into fossil fuels. The process is referred to as fossilization.

Disadvantages of Fossil Fuels:

The main disadvantages of using fossil fuels for the generation of electricity by using fossil fuel are listed as under :

1. Fossil fuels are non-renewable sources of energy and, once used cannot be renewed.
2. Burning fossil fuels causes air pollution.
3. The fossil fuel reserves on the earth are limited and may get exhausted soon.

Hydroelectricity:

When the water flowing in a river is stored in a high rise dam and allowed to fall from the top of the dam. The water rushes down with a great force, which can be utilized to drive a large water turbine. These turbines are connected to electric generators, which generate electric current. The electricity generated in this process is termed hydroelectricity or hydel power. The process involves the transference of the potential energy of the water into kinetic energy and then into electric energy.

Advantages of Generating Hydro-electricity:

The main advantages of using water energy for the generation of hydroelectricity are listed as under:

1. It is readily and abundantly available everywhere free of cost.
   1. It is eco-friendly and does not produce any kind of environmental pollution.
   1. It is a renewable source as water itself is a renewable and inexhaustible resource.
   1. It is a cheap source of energy, as it does not involve any costly investment.

Disadvantages of Generating Hydroelectricity:

1. It requires a large area to be built up.
2. A hydroelectric power plant is expensive to build.
3. It displaces people from their homes.
4. It cannot be built in any desired place.
5. It impacts aquatic life.

Thermal Power Plant

The thermal power station is based on the following principles:

1. It converts the chemical energy of fuel into electrical energy.
2. The chemical energy of fossil fuel is used to rotate the dynamo.
3. The working of the dynamo is based on electromagnetic induction.

Working of Power Station:

Fossil fuel is used as a source of energy in a power station. Combustion of fuel produces heat. This heat energy is used for heating water. At a certain temperature, water is converted into steam. Steam contains high energy. This steam is used to rotate the turbines. Turbines work on the principle of electromagnetic induction. If there is a relative motion between a magnet and the coil of insulated copper wire it produces voltage.

Advantages of Thermal Power Plant:

1. Construction and mechanism of the thermal power plant are easy.
2. Coal is used as fuel in thermal power plants and is cheaper than other fossil fuels.

Disadvantages of Thermal Power Plant:

1. Thermal power plant requires fuel such as coal and petroleum. We know that sources of coal are limited.
2. Thermal power plants cause air pollution. Combustion of coal produces smoke in the air leading to an increase in air pollution.
3. Thermal power plants require a large amount of water to produce steam.
4. Thermal power plants must be built near the mines because the transportation of fuel is much more expensive.
5. Building and maintenance cost of the thermal power plant is high.

Questions and Answers

Question 1:  Reena’s father works with a company that builds dams. Once he took her to the site where a dam was being built. Reena saw a group of people sitting there and shouting slogans against the building of the dam. She talked to the group of people and asked them about their problems and then discussed it with her father. She then tried to convince the people to talk with the authorities and come to an amicable solution. The discussion was successful. Reena’s father was very proud of his daughter. Now answer the following questions:

1. Why was Reena’s father proud of his daughter?
2. Why was the group of people protesting against the building of the dam?
3. Reena’s contribution to the peaceful resolution of the conflict proved to boon for many citizens of the country. How?

Answer : 

1. She convinced the people by explaining to them the advantages of constructing a dam and coming up with a solution for the rehabilitation of displaced people. So the contribution to the peaceful resolution of the conflict makes Reena’s father proud of his daughter.
2. The group of people was protesting against the building of the dam because of the following disadvantages:
3. A large area of agricultural land and human habitation is sacrificed as it gets submerged at the dam site.
4. Large ecosystems are destroyed when submerged underwater.
5. The decomposition of vegetation under anaerobic conditions produces methane gas which is also a greenhouse gas.
6.  
7. The citizens are not affected by the flood as it can be controlled by storing the water behind the dam.
8. Farmers get benefits as water for irrigation is available for the whole year.
9. Low cost of production of electricity gives monetary gain which is a boon to citizens.

Question 2: On returning home, Neha, an IXth std. sudent noticed that her 6-year-old brother Naresh, watching T.V. in the afternoon with all the lights and fans ‘on’. She noticed that the windows were closed and curtains were drawn, which made the room dark, so, Naresh put on the lights. She calmly opened the windows, and drew the curtain aside, which illuminated and aerated the room.

Then she made Naresh put “off” the lights and made him understand the reason behind her action. (Assume that they are getting electric supply from Thermal Power Plant)

1. List the two values exhibited by Neha.
2. Explain how she tried to give the same values to her brother.

Answer:

1. The values exhibited by Neha are:
2. Responsible citizen in the conservation of energy resources.
3. Adopting fuel and money-saving techniques in her life.

Neha tried to give the same values to her brother Naresh by opening the windows, and drawing the curtain aside, which illuminated and aerated the room. This way she shows the practice of adopting renewable sources of energy like solar energy and conserving fossil fuels like coal.

Summary

• Coal, petroleum, and natural gas are fossil fuels. They are exhaustible.
• A few of the conventional sources of energy are:
• Wind energy
• Thermal power plant
• Hydropower plant
• Biomass energy
• Fossil fuel
• They are used extensively and meet a marked portion of our energy requirement.
• A few of the non-conventional sources of energy are:
• Solar energy
• Ocean energy
• Geothermal energy
• Nuclear energy
• They are not used as extensively and meet our energy requirement only on a limited scale.