IGNOU FST CHAPTER 17 Q1

Q)Describe the various renewable resources of energy that have the potential to fulfill the needs of the society.

Ans)Solar Energy

The energy we get from the fossil fuels like coal, is in reality sun’s energy, trapped in them millions of years ago plants make their food and grow because they use solar energy for photosynthesis. Millions of years ago, huge forests got buried in the earth’s crust and under great pressure and temperature, they were converted into coal or oil. Hence coal and oil are called fossil fuels. Solar energy is the great source for production of vegetation which serves as food and fuel for us.

Wind Energy

Like solar energy, wind flow can also be harnesses to obtain mechanical energy for fetching water from the wells or from rivers. Once the windmill is turning due to the force of the wind, it may as well run a generator to get electrical energy. In the coastal and hilly regions, where wind blows at high speed, windmill can be used for the supply of electricity to a small town. Windmills have been used since long in many countries, but in India they have been only recently introduced.

Wave and Tidal Energy

Waves and tides are another source of energy which is perpetual and can be converted into electric energy, particularly where sea water can move into a narrow cut, such as is provided naturally, where rivers flow into the sea. Energy carried by water has also been widely used in India’s hilly regions, since a wheel with pedals can be made to run when it is put in a fast flowing stream. Flour mills of small size bult on this principle were used in Kashmir for long time. In fact, large “hydroelectric” power stations work on the same principle. A natural or artificial water fall is made to turn a modern kind of pedal wheel, called a turbine,  which rotates and causes electricity to be generated.

Geothermal Energy

Hot water superheated steam of hot springs are a natural phenomenon and be used to genenerate electricity. In our country there are 46 hydrothermal areas where the temperature of the spring water exceeds 150⁰C. These hot springs can be used to generate electricity for heating homes or glass houses to grow vegetables.

Atomic Energy

In view of the fast depletion of the non-renewable resources like coal and petroleum and because of pollution  which power stations burning coal cause, there has been a move to use other means of obtaining energy. Since the energy of the atom had already been unleashed in the form of a bomb, efforts were made to release atomic energy in a controlled manner. The device used for this purpose is called an atomic reactor. Nuclear reactors produce heat which is commonly used to raise steam, which rotates turbines and generators of electric power. It is estimated that 1 kg of natural uranium, written as U²³, generates energy equal to that produced by 35,000 kg of coal. Thus production of energy from nuclear fuel like uranium is efficient, and since great loads of coal or diesel are not consumed daily, this energy is convenient.