(a) Examine the role of petroleum in an economy.

(i) Petroleum is the primary source of energy in the world. Petroleum provides fuel for transportation throughout

(ii) the world.

(iii) It provides heat and lighting for homes, businesses and industries. It also provides lubricants for machinery and raw

(iv) materials for a number of manufacturing industries.

(v) Petroleum refineries act as a “nodal industry” for synthetic textile, fertilizer and numerous chemical industries.

(vi) It generates millions of jobs worldwide.

(vii) Control over petroleum resources is vital for geo political security.

(b) Examine the various sources of electricity and their environmental impacts.

(i) Electricity is generated by running water which drives hydro turbines to generate hydroelectricity.

(ii) It is also generated by burning other fuels such as coal, petroleum and natural gas to drive turbines to produce thermal power.

(iii) There are many non-conventional ways in which electricity is generated. Renewable energy sources like solar energy, wind, tide, biomass and energy from waste material and nuclear energy can also be used to generate electricity.

(iv) Photo voltaic technology converts sunlight directly into electricity. Due to tropical location of India, we have great potential for solar energy.

(v) Farm, animal and human wastes are used to produce bio-gas for domestic consumption in rural areas. Decomposition of organic matter yields gas, which has higher thermal efficiency.

(vi) India has potential for wind power and can be used effectively.

(vii) Oceanic tides can be used to generate electricity.

(viii) Geo thermal energy refers to the heat and electricity produced by using the heat from the interior of the earth.

Impact on the environment

(i) Increasing use of fossil fuel are causing environmental problems.

(ii) Therefore, big solar power plants are being established in different parts of India to minimize the dependence of rural households on firewood and dung cakes, which in turn will contribute to environmental conservation and adequate supply of manure in agriculture.

(iii) Biogas is by far the most efficient use of cattle dung and provides twin benefits to the farmer in the form of energy.

(iv) It improves the quality of manure.

(v) Prevents the loss of trees and manure due to burning of fuel wood and cow dung cakes.