Sources of Energy
Electrical energy is produced from various energy sources and some of them are listed below.
1) The Sun 2) The wind 3) Water 4) Fuels 5) Nuclear Energy
Of this solar energy and wind energy is not exploited much since it has got many limitations the other energy sources like water,fuel and nuclear sources are used world wide.
The sun
the sun is considered as the prime source of energy.The energy radiated from sun can be focussed on a small area by means of some reflectors.And thus it produces heat and this heat could be used to make steam by heating water and this steam could be used to rotate a turbine coupled to an alternator which would convert the mechanical energy so produced in the turbine to electrical energy.But it has got many limitations since reflectors are needed in large amount to produce sufficient heat to produce adequate amount of steam for power production.It would become difficult in the case of cloudy and rainy days.
There is another method by which solar energy could be used to produce electrical energy ie by using solar cells.The cells are made of silicon or material like galium arsenide and this convert solar energy directly into elecrical energy but the efficiency of conversion is much lower and is about only a maximum of 23%.It has also got the same disadvantage that the power could not be produced during cloudy and rainy days.But the solar cells and plants are implemented on places where intense solar radiation are available and other natural sources lacks.But its quite useful in the power production in small scale.
The Wind
This method could be employed in places where wind energy is available for a prolonged time.Here the enegy conversion is done with the help of a device called windmill.Windmill has got a fan or say blades with adequate length coupled to a generator.When wind blows the blade rotates and the generator starts working and the electrical energy soproduced in stored in batteries.The main disadvantage of this method is that this in not reliable source of energy.the output depends on the intensity of wind and the power output is small in all cases.But it is useful in coastal areas and hilly areas where the wind energy is surplus.And it is much economical compared to other methods of electricity production.
Water
When water is stored in higher places or say a reservoir the water head has got a potential energy.This potential energy culd be converted to mechanical and finally into electrical energy.The water at high head is made to pass through a penstock and made to strike on a turbine where the potential energy is converted into mechanical energy and this later converted to electrical energy by means of an alternator.This is the most common method used for current production.And dams are created to make water reservoirs with high heads.Though the inital cost is little higher for the construction of infrastructure the running cost is much lower and so it is one of the most economic method for large amount of power production.
Fuels
The water resources may not be available all through the season so we have to find any other source so we started using fuels.The fules could be solids like coal ,lignite etc liquids like diseal,petrol etc and gases like natural gas,petroleum gas etc.The energy so produced by the burning of fuels is used to rotate the turbine and hence alternator coupled with the priome mover.It is the most reliable method of power production but the cost is higher due to the large amount of fuels required and costlier compared to hydo electrical projects.And our fast depleting fuel sources force as to exploit more and more hydal sources to meet our power requirements.
Nuclear Energy
Towards the end of second world war it has been discovered that the nuclear fission reaction of substance like uranium,neptunium etc librates large amount of energy and we could use that energy for power production.It is estimated that the heat produced by 1kg of nuclear fuel is same as that produced by 45000 tonnes of coal.So this method could be employed for the production of steam and could use this to rotate the prime mover and the alternator coupled to it .This altenator converts mechanical energy into electrical energy.But the nuclear energy is not used very widely fo r the power production because of the less availablity of nuclear materials,much saftey preacation are needed,it produces radio active waste materials which may even result in mutation and higher cost.
Written by John on September 18th, 2008 with
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