Importance of Electrical Energy
The Power system is defined as the system which involves generation, Transmission and distribution, Protection and utilization of electrical power
1. Energy exists in different forms in nature but the most important form is the electrical energy. The modern society is so much dependent upon the use of electrical energy that it has become a part and parcel of our life.
2. 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.
3. Electricity has many uses in our day to day life. It is used for lighting rooms, working fans and domestic appliances like using electric stoves, A/C and more. All these provide comfort to people. In factories, large machines are worked with the help of electricity. Essential items like food, cloth, paper and many other things are the product of electricity.
4. Modern means of transportation and communication have been revolutionised by it. Electric trains and battery cars are quick means of travel. Electricity also provides means of amusement, radio, television and cinema, which are the most popular forms of entertainment are the result of electricity. Modern equipment like computers and robots have also been developed because of electricity. Electricity plays a pivotal role in the fields of medicines and surgery too — such as X-ray, ECG. The use of electricity is increasing day by day.
5. 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.
Generation of Electricity
Electrical Power is generated by plants called generating stations. A generating station consists prime mover coupled with alternator for production of electricity. Prime mover(Turbine) converts energy from some other form into mechanical energy and alternator converts mechanical energy into electrical energy. They different forms of electric generating stations are
1. Hydroelectric generating station
2. Steam/thermal generating station
3. nuclear generating station
4. Diesel generating station
Sources of Energy
Electrical energy is obtained by converting some form into electrical enrgy by use of turbine – alternator combination. The various sources of energy available are
1. Sun: – The Sun is the primary source of energy. The heat energy radiated by the Sun can be focussed over a small area by means of reflectors. This heat can be used to raise steam and electrical energy can be produced with the help of turbine-alternator combination. However, this method has limited application because:
(a) it requires a large area for the generation of even a small amount of electric power
(b) it cannot be used in cloudy days or at night
2. Wind: – This method can be used where wind flows for a considerable length of time. The wind energy is used to run the wind mill which drives a small generator. In order to obtain the electrical energy from a wind mill continuously, the generator is arranged to charge the batteries. These batteries supply the energy when the wind stops. This method has the advantages that maintenance and generation costs are negligible. However, the drawbacks of this method are
(a) variable output, (b) unreliable because of uncertainty about wind pressure and (c) power generated is quite small