Sources Of Electrical Energy :
Since electrical energy is produced from energy available in various forms in nature, it is desirable to
look into the various sources of energy. These sources of energy are :
(i) The Sun
(ii) The Wind
(iii) Water
(iv) Fuels
(v) Nuclear energy.
Out of these sources, the energy due to Sun and wind has not been utilised on large scale due to
a number of limitations. At present, the other three sources viz., water, fuels and nuclear energy are
primarily used for the generation of electrical energy.
The 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
(c) it is an uneconomical method.
Nevertheless, there are some locations in the world where strong solar radiation is received very
regularly and the sources of mineral fuel are scanty or lacking. Such locations offer more interest to the solar plant builders.
The 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 thectrical 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.
Water
When water is stored at a suitable place, it possesses potential energy because of the
head created. This water energy can be converted into mechanical energy with the help of water
turbines. The water turbine drives the alternator which converts mechanical energy into electrical
energy. This method of generation of electrical energy has become very popular because it has low
production and maintenance costs.
Fuels
The main sources of energy are fuels viz., solid fuel as coal, liquid fuel as oil and gas
fuel as natural gas. The heat energy of these fuels is converted into mechanical energy by suitable
prime movers such as steam engines, steam turbines, internal combustion engines etc. The prime
mover drives the alternator which converts mechanical energy into electrical energy. Although fuels continue to enjoy the place of chief source for the generation of electrical energy, yet their reserves are diminishing day by day. Therefore, the present trend is to harness water power which is more or less a permanent source of power.
Nuclear Energy
Towards the end of Second World War, it was discovered that large amount
of heat energy is liberated by the fission of uranium and other fissionable materials. It is estimated that heat produced by 1 kg of nuclear fuel is equal to that produced by 4500 tonnes of coal. The heat produced due to nuclear fission can be utilised to raise steam with suitable arrangements. The steamcan run the steam turbine which in turn can drive the alternator to produce electrical energy. However,.there are some difficulties in the use of nuclear energy. The principal ones are
(a) high cost of nuclear plant
(b) problem of disposal of radioactive waste and dearth of trained personnel to handle the plant.
Comparision Of Energy Sources
Since electrical energy is produced from energy available in various forms in nature, it is desirable to
look into the various sources of energy. These sources of energy are :
(i) The Sun
(ii) The Wind
(iii) Water
(iv) Fuels
(v) Nuclear energy.
Out of these sources, the energy due to Sun and wind has not been utilised on large scale due to
a number of limitations. At present, the other three sources viz., water, fuels and nuclear energy are
primarily used for the generation of electrical energy.
The 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
(c) it is an uneconomical method.
Nevertheless, there are some locations in the world where strong solar radiation is received very
regularly and the sources of mineral fuel are scanty or lacking. Such locations offer more interest to the solar plant builders.
The 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 thectrical 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.
Water
When water is stored at a suitable place, it possesses potential energy because of the
head created. This water energy can be converted into mechanical energy with the help of water
turbines. The water turbine drives the alternator which converts mechanical energy into electrical
energy. This method of generation of electrical energy has become very popular because it has low
production and maintenance costs.
Fuels
The main sources of energy are fuels viz., solid fuel as coal, liquid fuel as oil and gas
fuel as natural gas. The heat energy of these fuels is converted into mechanical energy by suitable
prime movers such as steam engines, steam turbines, internal combustion engines etc. The prime
mover drives the alternator which converts mechanical energy into electrical energy. Although fuels continue to enjoy the place of chief source for the generation of electrical energy, yet their reserves are diminishing day by day. Therefore, the present trend is to harness water power which is more or less a permanent source of power.
Nuclear Energy
Towards the end of Second World War, it was discovered that large amount
of heat energy is liberated by the fission of uranium and other fissionable materials. It is estimated that heat produced by 1 kg of nuclear fuel is equal to that produced by 4500 tonnes of coal. The heat produced due to nuclear fission can be utilised to raise steam with suitable arrangements. The steamcan run the steam turbine which in turn can drive the alternator to produce electrical energy. However,.there are some difficulties in the use of nuclear energy. The principal ones are
(a) high cost of nuclear plant
(b) problem of disposal of radioactive waste and dearth of trained personnel to handle the plant.
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