Question

Sun is the ultimate source of energy. Explain.
Or
Energy from various sources is considered to have been desired from the sun. Do you agree ? Justify your answer.

Answer 1

1. Renewable sources of energy or inexhaustible sources of energy.
2. Non-renewable sources of energy or exhaustible sources of energy.

1. Renewable Sources of Energy
The sources of energy which are inexhaustible (i.e. which can never be finished) and are being continuously supplied by nature are known as renewable sources of energy. These sources of energy are also known as non-conventional sources of energy.
For example :

1. Wind
2. Hydro Power
3. The Sun
4. Ocean Tidals Energy
5. Interior Of the Earth
6. Biogas
7. Plants , vegetable , waste etc.

2. Non-Renewable Sources of Energy
The sources of energy which are exhaustible (i.e. which can be finished) and have been formed in nature long ago are known as non-renewable sources of energy. These sources of energy are also known as conventional sources of energy.
For example :

1. Coal
2. Petroleum
3. Natural Gas
4. Fissionable materials like Uranium.

Non-renewable sources of energy like coal, petroleum and natural gas have a huge deposit under the earth. However, the continuous extraction of these sources for the purpose of usable energy is a matter of concern and worry because ultimately the deposit of these sources will be completely finished. It may be noted that the formation of fossil fuel take very long period. Therefore, we should use these fuels judiciously so that their deposit may last long for future. On the other hand, renewable sources of energy will last forever. For example, it is estimated that the sun would continue to shine for another 55 billion years. Therefore, the sun as the source of energy will be available for a very long period of time. Similarly, bio-mass as the source of energy will be available for a longer period of time if we grow more and more plants periodically {i.e. at regular intervals of time). The wind energy will be at our disposal as long as the sun exists. Geo-thermal energy is another source which will be available forever.