Sources of Energy class 10 notes chapter 14-pathanto

The sources of energy which have been in use from a long time are called conventional sources of energy

There are two type of sources of energy:

i) Renewable Energy

ii) Non-Renewable Energy

i) Renewable Energy: The resources which can be renewed or reproduced by physical, chemical or mechanical processes are known as renewable For example, solar and wind energy, water,

ii) Non-Renewable Energy: These occur over a very long geological time. Minerals and fossil fuels are examples of such resources. These resources take millions of years in their formation. like fossil fuels

WHAT IS A GOOD SOURCE OF ENERGY?:
A good source of energy would be one
which would do a large amount of work per unit volume or mass,
be easily accessible,
be easy to store and transport
perhaps most importantly, be economical

Fuels: The substance which are burn to produced heat energy is called fuels like LPG ,CNG ,wood etc

Good or Ideal fuel :
i)A good source of should be one:
ii)Easily available
iii)Easy to store and transport
iv)proper ignition temperature
v)It should have a high calorific value

CONVENTIONAL SOURCES OF ENERGY:
The traditional source of energy which are used most of people are known as conventional sources of energy like wood, coal

Fossil fuels:Fossil fuels are formed due to compression of dead organic matter(plant and animals) over millions of years deep under the earth example coal or natural gas.
ii)The fossil fuels are non-renewable sources of energy, so we need to conserve them and we need to find alternate sources of energy

Disadvantages of fossil fuels: i) The oxides of carbon, nitrogen and sulphur that are released on burning fossil fuels are acidic oxides. These lead to acid rain which affects our water and soil resources
ii) the air pollution caused by burning of coal or petroleum products.
iii)The burning of fossil fuel produced high amount od CO₂ and other gases Which caused green-house effect

Controlling pollution : The pollution caused by burning fossil fuels can be reduced by increasing the efficiency of the combustion process and using various techniques like catalytic converter

Thermal power plants:Thermal power plants use steam produced by burning fossil fuels ( coal, oil gas) to move the turbines to generate electricity. are known as thermal power plants
ii) The transmission of electricity is more efficient than transporting coal or petroleum over the same distance so many thermal power plants are set up near coal or oil fields.
iii) The burning of coal heat up water to produce steam which runs the turbine to generate electricity.

Hydro Power Plants:

• Hydro power plants convert the potential energy of falling water into electricity
• Another traditional source of energy was the kinetic energy of flowing water or the potential energy of water at a height
• In order to produce hydel electricity, high-rise dams are constructed on the river so collect water in larger reservoirs
• The falling/flowing water moves the turbine, which with the help of a dynamo converts mechanical energy into electrical energy.

Advantages:
i)hydro power is a renewable source of energy which never get exhausted
ii)Dam help in contolling flood, and in irrigation

Disadvantage:
i)The dams can be constructed only in a limited number of places, preferably in hilly terrains
ii)Large areas of agricultural land and human habitation are to be sacrificed as they get submerged.
iii)Large eco-systems are destroyed when submerged under the water in dams

Conventional Sources of Energy:

Bio-Mass:cow-dung, various plant materials like the residue after harvesting the crops, vegetable waste and sewage are decomposed in the absence of oxygen to give bio-gas

Biogas Plant:

• The plant has a dome-like structure built with bricks
• A slurry of cow-dung and water is made in the mixing tank from where it is fed into the digester.
• The digester is a sealed chamber in which there is no oxygen
• Anaerobic micro-organisms that do not require oxygen decompose or break down complex compounds of the cow-dung slurry. when decomposition process to be complete and generate gases like methane, carbon dioxide, hydrogen and hydrogen sulphide.
• The bio-gas is stored in the gas tank above the digester from which they are drawn through pipes for use

Advantages:
i)Bio-gas is an excellent fuel as it contains up to 75% methane
ii)The slurry left behind is removed periodically and used as excellent manure, rich in nitrogen and phosphorous

Wind Energy:This kinetic energy of the wind can be used to generate electricity.

Windmill:



i)Wind Energy is harnessed by rotatory structures known as windmills.
ii)To generate electricity, the rotatory motion of the windmill is used to turn the turbine of the electric generator

Advantages: Wind energy is an environment-friendly and efficient source of renewable energy

Limitation:
i) High cost regular maintenance are required
ii) Large land area requires for installing windmill farm
iii)The wind speed should also be higher than 15 km/h to maintain the required speed of the turbine

ALTERNATIVE OR NON-CONVENTIONAL CONVENTIONAL SOURCES OF ENERGY:

Solar Energy:

• The Sun has been radiating an enormous amount of energy at the present rate for nearly 5 billion years and will continue radiating at that rate for about 5 billion years more
• The energy produce from the sun light is called solar eneergy

Solar Cooker:



The solar cooker is a device which is used to cooked food by heating energy radiated by the sun

• A black surface absorbs more heat as compared to other surface and solar cookers use this property by coating their insides black.
• solar cookers achieve a higher temperature by using mirrors to focus the rays of the Sun

solar cell:

Advantages: advantages associated with solar cells are
i) no moving parts
ii) require little maintenance and work quite
iii)can be set up in remote areas or very sparsely inhabited areas without the hassle and expenses of transmission lines.

Disadvantages:
i)the special grade silicon for making solar cells is limited
ii)Manufacture of solar cells is very expensive and silver used in it make high expensive

Used: solar cells are used artificial satellites and space probes like Mars orbiters and calculators

Energy from the Sea:

Tidal Energy:
i) The phenomenon of high and low tides and the difference in sea-levels gives is called tidal energy
ii)Tidal energy is harnessed by constructing a dam across a narrow opening to the sea
iii)A turbine fixed at the opening of the dam converts tidal energy to electricity.

Wave Energy:
the kinetic energy possessed by huge waves near the seashore can be used to generate electricity
ii)The waves are generated by strong winds blowing across the sea.
iii) devices have used to trap wave energy for rotation of turbine and production of electricity.

Ocean Thermal Energy:
i) This difference in temperature is exploited to obtain energy in ocean-thermal-energy conversion plants
ii)the temperature difference between the water at the surface and water at depths up to 2 km is 293 K (20°C) or more.
iii)The warm surface-water is used to boil a volatile liquid like ammonia. The vapours of the liquid are then used to run the turbine of generator.

Geothermal Energy:
Due to geological changes, molten rocks formed in the deeper hot regions of earth’s crust are pushed upward and trapped in hot spots Harnessing this heat energy is called geothermal energy.
ii)The steam trapped in rocks is routed through a pipe to a turbine and used to generate electricity

Nuclear Energy:Nuclear energy can be used to generate electricity by the process of nuclear fission.

nuclear fission:
when bombarded with low-energy neutrons, can be split apart into lighter nuclei. When this is done, a tremendous amount of energy is released The fission of an atom of uranium, for example, produces 10 million times the energy produced by the combustion of an atom of carbon from coal.

Nuclear fusion:
i)Fusion means joining lighter nuclei to make a heavier nucleus, most commonly hydrogen or hydrogen isotopes to create helium
ii) It releases a tremendous amount of energy, according to the Einstein equation

Disadvantages:
i)The major hazard of nuclear power generation is the storage and decaying into harmful subatomic particles (radiations).
ii) The high cost of installation of a nuclear power plant
iii)Limited availability of uranium
iv)Nuclear energy was first used for destructive purposes

Nuclear Energy: