Principles of Power System Notes

1.1. Importance of electrical energy

Energy may be needed as heat, as light, as motive power etc. The present-day advancement in science
and technology has made it possible to convert electrical energy into any desired form. This has
given electrical energy a place of pride in the modern world. The survival of industrial undertakings
and our social structures depends primarily upon low cost and uninterrupted supply of electrical
energy. In fact, the advancement of a country is measured in terms of per capita consumption of
electrical energy.
Electrical energy is superior to all other forms of energy due to the following reasons :
(i) Convenient form. Electrical energy is a very convenient form of energy. It can be easily
converted into other forms of energy. For example, if we want to convert electrical energy into heat,
the only thing to be done is to pass electrical current through a wire of high resistance e.g., a heater.
Similarly, electrical energy can be converted into light (e.g. electric bulb), mechanical energy (e.g.
electric motors) etc.
(ii) Easy control. The electrically operated machines have simple and convenient starting, control
and operation. For instance, an electric motor can be started or stopped by turning on or off a switch.
Similarly, with simple arrangements, the speed of electric motors can be easily varied over the desired
range.
(iii) Greater flexibility. One important reason for preferring electrical energy is the flexibility
that it offers. It can be easily transported from one place to another with the help of conductors.
(iv) Cheapness. Electrical energy is much cheaper than other forms of energy. Thus it is overall
economical to use this form of energy for domestic, commercial and industrial purposes.
(v) Cleanliness. Electrical energy is not associated with smoke, fumes or poisonous gases.
Therefore, its use ensures cleanliness and healthy conditions.
(vi) High transmission efficiency. The consumers of electrical energy are generally situated
quite away from the centres of its production. The electrical energy can be transmitted conveniently
and efficiently from the centres of generation to the consumers with the help of overhead conductors
known as transmission lines.