Question

Energy from various sources is considered to have been derived from the Sun. Do you agree? Justify your answer by giving two examples.

Answer 1

Yes, sun is the ultimate source of energy directly or indirectly, all the forms of energy derived from solar energy.
(i) Non-renewable sources of energy: Fossil fuels like coal, petroleum, and natural gas are formed due to the burial of large plants and ancient creatures whose ultimate source of energy is the sun.
(ii) Renewable sources of energy: They are indirectly derived from solar energy such as:

(a) Energy from flowing water: In lakes, rivers, seas etc., evaporates due to solar energy. They bring rainfall and snowfall.
(b) Wind energy: Wind energy arises due to uneven heating of the earth’s surface by the sun rays at two different adjoining places. Due to this, wind possesses kinetic energy.
(c) Bio-energy: Plants in the process of photosynthesis convert solar energy into food (chemical energy). This food is consumed by animals.
(d) Wave energy: The waves are generated by strong winds (due to solar energy) blowing across the sea.
(e) Ocean thermal energy: Sun is responsible for the temperature difference between the water at the surface and water at depth in seas and oceans

(iii) Solar devices : They derive their energy directly from solar energy and convert it into other usable forms of energy.