Energy

We do lots of work in a day. To lift up heavy things, to push objects, for writing, cooking our body requires specific capacity. The capacity to do certain work is called energy.Energy is required to do any sort of work.

Similarly Plants, animals, vehicles and machines requires energy to work.

Energy is available in environment in different forms.

Solar energy is the main source of energy.It gets converted in different forms of energy.

Solar Energy

Chemical

Magnetic

Atomic Energy

Electric

Sound

Mechanical Heat

Light

Different forms of energy can be changed from one form to another.

• The energy from the sun is absorbed by animals and plants. They are nourished by the sun’s energy. Solar energy gets stored in their bodies in their bodies in the form of chemical energy.

Fossil Fuel

• A long time ago, remnants of plants and animals got buried into the earth. Due to the effect of the tremendous pressure of the layers of earth above and the heat inside they were converted into fuels.The energy left behind was in the form of hydrocarbon compounds. So these remains

were converted into fuels. Such

fuels are called fossil fuels. It takes of lakh of years for such fuels to be formed and hence the stores of fossil fuel are limited.

Types of Fossil Fuels

• Fossil fuels are found in three forms – Solid, Liquid as well as gaseous.

Solid Coal From the remains of plants

Liquid Mineral Oil Marine plants and animals

Gaseous Natural Gas Marine plants and animals

Solid Fuels• Wood, charcoal, cowdung pats are solid fuels.• Convenience– Easily available, cheap.• Limitation – Less combustible, Creates pollution via

burning.,destruction of forests, has endangered the environment . Burning of cowdung pats destroys nitrogen contents. Charcoal is formed when wood is burnt in insufficient air. Charcoal burns amokelessly.

Liquid Fuels

• Mineral oil is found nearly 25,000 metres deep in the bowels of the earth. Petrol, diesel, kerosene and fuel oil can be obtained from it.

• Convenience: Causes less pollution as compared ti highly combustible solid fuel.

• Limitation: Polluting gases are generated. Inconvenient for motor vehicles.

Gaseous Fuels

• Methane, ethane, propane, butane, etc are the

various types of natural gas.• The gas filled in cylinder which we use for cooking is

butane.• Convenience: Very convenient fuel to use, lights up

quickly, doesn’t leave behind any solid substance

after burning. Easy to transport from it’s main source by means of pipes. Burning and use of natural gas can be easily controlled. It’s burning doesn’t produce any pollutants.

Increasing use of energy

• Because of increasing population, industrialisation use of energy has increased.

• The deposits of fossils and other fuels is limited and hence they cannot be permanent sources of energy.

• Hence it is necessary to search for alternate sources of energy.

Conventional sources of energy - Problems.

• Carbon dioxide emitted is causing a rise in global atmospheric temperature.

• Gases release in the atmosphere have given rise to dangers like acid rain.

• Holes in the ozone layer of the atmosphere are allowing the passage of harmful rays.

• Unrestricted cutting down of trees has caused degradation of forests.

Because of all these reasons the need for alternate source of energy has aroused.

Non-conventional or Renewable sources of energy

• Earlier sources of energy like wind energy, hydro-electric energy, biogas, biodiesel, energy generated through sea water were not used often .So these are

called as non-conventional energy sources.• Even though they are used again and again energy

gets generated in some time. Also the energy source doesn’t get depleted and hence is unlimited. And hence they are called renewable sources of energy.

Solar Energy

• Solar Cooker, Solar heater, Solar Cell, are some of the devices running on solar energy.

Use of Atomic energy - Option for

depleting energy sources.• Uranium atoms are bombarded with neutrons to

obtain atomic energy.• At Tarapur in Maharashtra and at Kakrapur in

Surat(Gujrat) governmet has set up atomic centres.

Government’s plan to meet the energy crisis

• Finding out new sources of energy• Giving preference to renewable sources of energy.• Using non-renewable sources of energy responsibly

and sparingly. Educating the public about these issues.

• Promoting the use of devices that consume less fuel.