Man has needed and used energy at an increasing rate for sustenance and well-being ever since he came on the earth a few million years ago. Primitive man required energy mainly in the form of food. He got this by eating plants or animals which he hunted. Subsequently he discovered fire and learnt how to use it. He used fire for cooling as well as for keeping himself warm. Thus his energy needs increased day by day and he started to make use of wood and other biomass to supply the energy.
After a while, man started to cultivate land for agriculture. For domesticating and training animals to work for him he needs more energy. With further demand for energy, man began to use the wind for sailing ships and for driving windmills, and the force of falling water to turn water wheels. Till this time it would not be wrong to say that the sun was supplying all the energy needs of man either directly or indirectly and that man was using only renewable sources of energy.
With the discovery of the steam engine (A.D 1700), the Industrial Revolution began and brought about a great many changes. For the first time, man started to use a new source of energy – coal, in large quantities. A few years later, the other fossil fuels, oil and natural gas began to be used extensively. The fossil fuel era of using nonrenewable sources had begun.
Man started to produce electricity using either fossil fuels or water power and he developed power generating stations. The electricity brought a great change in man’s movement. For the first time, man got the power of machine.
A new source of energy- nuclear energy- came on the scene after the Second World War.
Already, nuclear energy is providing a small but significant amount of the energy requirements of many countries.
In the past few years, it is obvious that fossil fuel resources are fast depleting .This is particularly true for oil and natural gas. Thus the fossil fuel era is gradually coming to an end. Based on the World wide survey(shown in fig.), it will now be possible to make some observations and draw some conclusions for the world as a whole.
a) The production of oil appears at maximum around 1980 and is now slowly declining. On the other hand, the production of natural gas is still rising. Present data shows that most of the reserves of oil and natural gas are likely to be consumed in another 50 years.
b) As oil and natural gas become scarcer, a great emphasis will fall on coal. The production of coal likely will touch a maximum somewhere between the years 2030 and 2060 and it could be consumed by 2250 AD.
Thus the need for alternative energy sources will be established. Now it is obvious that though man’s large scale use of commercial energy (coal, oil, natural gas, hydroelectric power and nuclear power) has brought a better quality of life, it has also brought many problems. Perhaps the most serious of these is the harmful effect on the environment. It causes serious air pollution problems in many areas because of the localized release of large amounts of harmful gases into the atmosphere. It causes the phenomenon of global warming which now a matter of great concern. Keeping the environment in mind, now we are badly in need of alternative energy sources. Later part of this sires, I’ll discus about some of them.
Thank you.
