Power Plant Engineering

38 POWER PLANT ENGINEERING

Distribution of World Oil Reserves

66.3% Middle East

6% Africa

8.4% North America

5.0% Far East/Oceania

5.9% East Europe

1.5% West Europe

6.9% Central South America

*This was the reason for the gulf war.

2.8 Indian and Global Energy Sources

We do different types of work every day. Energy is required for it. Heat energy from burning

fuels like wood, coal, petrol and cooking gas are widely used for cooking and other purposes. Different

forms of energy are converted into electrical energy. The electrical energy thus obtained is used to

operate radio, television, and lamps and to run vehicles and heavy machines in factories. Think of a

situation where there is no energy. Not only our daily activities but also our life will come to a stand still.

Thus energy is an inseparable part of our life. This topic deals with different sources of energy and their

characteristics.

Sources of energy are those, which can supply adequate amount of energy in a suitable form for

long periods. The major sources of energy, aside from human and animal power, are petroleum re-

sources, natural gas, coal, hydropower, biomass, geothermal, nuclear, wind and solar. Theoretically

these resources can be substituted for one another in order to perform a specific task. However, in

practice, substitution would be subject to technical and economic limitations that circumscribe the use

of such energy resources for specific purposes at given locations and periods of time. Few energy re-

sources are used and consumed at the same location in which they are found, and most of them require

generally elaborate transportation and conversion facilities to make them useful for performing the

intended task. Analysis of energy resources, therefore, should cover availability and also the production,

processing and distribution facilities. Some of the energy sources are:

2.8.1 The Sun

Sun is the source of many forms of energy available to us. The most abundant element in sun is
hydrogen. It is in a plasma state. This hydrogen at high temperature, high pressure and high density
undergoes nuclear fusion and hence releases an enormous amount of energy. This energy is emitted as
radiations of different forms in the electromagnetic spectrum. Out of these X-rays, gamma rays and most
of ultraviolet rays do not pass through the earth’s atmosphere. But heat energy and light energy are the
main radiations that reach the earth. This energy is the basis for the existence of life on earth.
Sun is a sphere of intensely hot gaseous matter with a diameter of 1.39e^9 m and 1.5e^11 m away
from earth. Sun has an effective black body temperature of 5762 K and has a temperature of 8e^6 K to
40e^6 K. The sun is a continuous fusion reactor in which hydrogen (4 protons) combines to form helium
(one He nucleus). The mass of the He nucleus is less than that of the four protons, mass having been lost
in the reaction and converted to energy. The energy received from the sun on a unit area perpendicular to
the direction of propagation of radiation outside atmosphere is called solar constant, and has a value
1353 Wm– 2. This radiation when received on the earth has a typical value of 1100 Wm– 2 and is variable.