Conventional & Non-conventional Sources of Energy

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 of fossil fuels causes air pollution. 

3. The fossil fuel reserves in the earth are limited and may get exhausted soon. 

2. 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 utilised to drive large water turbine. These turbines are connected with electric generators, which generate electric current. The electricity generated in this process is termed as hydro electricity or hydel power. In fact, the process involves transference of 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 hydro electricity are listed as under: 

1. It is readily and abundantly available everywhere free of cost. 

2. It is eco-friendly and does not produce any kind of environmental pollution. 

3. It is a renewable source as water itself is a renewable and inexhaustible resource. 

4. 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 the aquatic life. 

3. Thermal power plant 

Thermal power station is based on the following principles: 

1. It converts chemical energy of fuel into electrical energy.  

2. Chemical energy of fossil fuel is used to rotate the dynamo.  

3. Working of the dynamo is based on electromagnetic induction.  

Working of power station:  

Fossil fuel is use as a source of energy in power station. Combustion of fuel produces heat. This heat energy is used for heating water. At 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 magnet and the coil of insulated copper wire it produces voltage. 

Advantages of thermal power plant:  

1. Construction and mechanism of thermal power plant is easy.  

2. Coal is used as fuel in thermal power plant and is cheaper than other fossil fuels.  

Disadvantages of thermal power plant:  

1. Thermal power plant requires fuel as coal and petroleum. We know that sources of coal are limited.  

2. Thermal power plant makes air pollution. Combustion of coal produces smoke in the air leads to an increase in air pollution.  

3. Thermal power plants require large amount of water to produce steam.  

4. Thermal power plants must be built near to the mines because transportation of fuel is much expensive.  

5. Building and maintenance cost of 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 dam. She talked 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 dam? 

3. Reena’s contribution to the peaceful resolution of the conflict proved to boon for many citizens of the country. How? 

Answer :  

1. Because she convinced the people by explaining them the advantage of constructing dam and come with a solution of rehabilitation of displaced peoples. So the contribution to the peaceful resolution of the conflict make Reena’s father proud of his daughter. 

2. The group of people was protesting against the building of dam because of the following disadvantages: 

1. A large area of agricultural land and human habitation are sacrificed as it gets submerged at the dam site. 

2. Large ecosystems are destroyed when submerged under water. 

3. The decomposition of vegetation under anaerobic condition produces methane gas which is also a greenhouse gas. 

3.  

1. The citizens are not affected by flood as it can be controlled by storing the water behind the dam. 

2. Farmers get benefited as water for irrigation is available for the whole year. 

3. Low cost of production of electricity gives monetary gain which is a boon to citizens. 

Question 2: On returning home, Neha, a IXth std. student noticed that her 6 years old brother Neresh, 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 had put on the lights. She calmly opened the windows, 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 same values to her brother. 

Answer: 

1. The values exhibited by Neha are: 

1. Responsible citizen in the conservation of energy resources. 

2. Adopting fuel and money saving techniques in her life. 

Neha tried to give the same values to her brother Naresh by opening the windows, 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 the 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
  • Hydro power 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.