What are the conventional sources of energy for mankind

Energy & Environmental Engineering | Environmental Science | HOTS Questions | Important Questions

 

Q. What are the conventional sources of energy for mankind? (R.GP.V., June 2012)

Ans. The major conventional sources of energy are -

(i) Fossil Fuels - Fossil fuels are the primary source of energy. They are formed by the anaerobic decomposition of plants and dead organisms lying deep below the earth under the effect of temperature and pressure. The decomposition in the absence of oxygen and under high heat and pressure converted the dead matter into hydrocarbons. The fossil fuels can be either of the form solid (coal), liquid (crude oil), and gas (natural gas). These are non- renewable sources of energy because once burnt, they are finished and their replenishment can take another millions of years, which is nearly impossible for mankind to exist.

(ii) Hydro Power - Water energy is most conventional renewable energy source and obtained from water flow. Water energy is developed by allowing water to fall under the force of gravity from height. Generally hilly and highland areas are suitable for generation of water energy. Water power is used almost exclusively for electric power generation. Potential energy of water is converted into mechanical energy by using turbines and this mechanical energy is used to develop electricity. Water power is much cheap in the locality where water is easily available in abundance. Although initial cost of hydroelectric power plants is higher as compared to other types of power plants but their operating costs are much less, as there is no consumption of fuel in operation of these power plants.

Hydro power is clean and non-polluting source of energy. It can be transmitted to the long distances with the help of wires or cables. This type of energy cannot be stored anywhere so as markets should be fixed before generation of this type of energy.

(iii) Nuclear Power - Energy released during a nuclear reaction in accordance with the mass-energy equation is called nuclear energy. According to Einstein mass energy equation,

E = mc2

where
E Energy obtained by conversion of matter into energy
c = Speed of light
m= Lost mass which is converted into energy called binding energy.

Binding energy is the energy which keeps the nucleus of every atom from flying apart. This binding energy when released slowly and under control produces heat which can be used to drive steam-driven electric generators to produce power.

A small quantity of radioactive material can produce an enormous amount of energy. Atoms in matter has high concentration of binding energy. Controlled fission of heavier unstable atoms such as U235, Th232 and Pu239 liberates a large amount of heat energy. For example, complete fission of 1 kg of U235, gives energy which can be obtained by burning 4500 tonnes of coal or 2200 tonnes of oil.