(a) The reasons for necessity of use of non-conventional energy sources in our country are as follows :
(i) The conventional sources of energy are depleting very fast and we are dependent on imports of petroleum_and natural gas to meet our needs.
(ii) Renewable energy sources do not cause environmental pollution with their use and so, to preserve our environment, we must change over to use more of such sources.
(iii) Non-conventional sources of energy are very economical in use as compared to conventional sources. Thus, to save expenses, we should use renewable energy sources.
(b) From the above question, I have learnt the importance of non-conventional sources of energy in our day-to-day life.
(ii) It is expected that use of solar energy will be able to minimise the dependence of rural households on firewood and dung cakes.
(iii) Due to rising prices, serious environmental threats and much longer period in replenishment of oil and gas, there is a need to shift to non-conventional sources of energy like solar energy.