Saturday, January 28, 2017
GENERATION OF ELECTRICAL ENERGY
Energy exists in different forms in nature but the most important form is the electrical energy.Now a days usage of electricity is very high it has become a basic need for everyone.
Why electrical energy why not other energy sources?
Well, the simple answer to this is the modern technology has developed in such a way that electrical energy can be easily converted into all other energy forms. It also has other advantages as mentioned below.
1.Greater flexibility: As it can be easily transported with the help of conductors from one place to other it has great flexibility.
2.Convenient : As it can be easily converted into other forms of energy it is very convenient form. If we take the example of converting electrical energy into heat energy all we need to do is just pass electricity through a resistor then electrical energy converts o heat energy. Similarly, all the others forms of energy like light,mechanical etc can be obtained easily from electrical energy.
3.Cheapness: When compared to other forms of energy electrical energy is much cheaper . Thus it is economical to use for any purpose.
4.Cleanliness: Electrical energy doesn't produce smoke,ash or poisonous gases. So it maintains cleanliness.
5.Easy control: The electrically operated machines can be controlled easily by switching on or off the switch. For example we can turn off or on the fan by switching off or switching on the switch. And speed can also be easily controlled for example speed of fan can be adjusted by using a regulator. So it is easy to control.
6.High transmission efficiency: Consumers of electrical energy are located away from the electricity generation stations generally.But with the help of over head line conductors and by using transformers and few other equipment's electricity can be supplied efficiently with less amount of losses.
The above mentioned advantages made usage of electrical energy popular than other energy forms.
Generation of electrical energy:
Converting different forms of energy that are present in nature into electrical energy is known as generation of electrical energy.
To get the basic idea of generation of electrical energy observe the following figure.
Energy from any of the sources like heat, wind, hydro, fossil etc can be given as input to the prime mover. For example take hydro energy, Water at certain head when falls on the prime mover which is a rotating part rotates the prime mover in this way the potential energy exerted on it is converted to mechanical energy. This prime mover drives generator and the generator converts mechanical energy to electrical energy.
Sources of energy:
1. Fuels: Fuels like coal, oil and natural gas are the main sources of energy. The heat energy produced by these fuels is converted into mechanical energy by certain type of prime movers like steam engines, steam turbines etc. The prime mover drives the alternator which converts mechanical energy into electrical energy. Although these fuels play main role in the electrical energy production now a days we need to see other alternatives as there quantity is diminishing due to increase in the usage of electrical energy. The alternative to them is renewable energy sources likes solar, wind, hydel.
2.Solar energy: Sun is the major source of energy. Electrical energy can be produced from sun by focusing the heat energy produced by sun on reflectors and heating water which produces steam which in turn rotates the turbine which is coupled to the generator and this generator converts mechanical energy to electrical energy. As it has limitations like availability of solar energy is not possible all the time it can be used as alternative wherever other sources of energy are not available abundantly.
3.Water: When water present at certain head falls down on turbine the potential energy possessed by water is converted into mechanical energy by a water turbine. This turbine drives the generator which converts mechanical energy to electrical energy.
4. Wind: To generate electrical energy from wind energy a wind mill is established. This runs the generator which produces electrical energy. Wind mills are generally placed at hilly areas.It is cheaper way to generate electrical energy.
5.Nuclear energy: Very large amount of heat can produced by nuclear fuels like uranium. This heat energy is utilized to produce steam. This stem rotates the steam turbine and runs the generator which can produce electrical energy.
This helps you to understand the basics of generation of electrical energy from different power plants.
Efficiency:
Some energy is lost i.e converted to other form of energy other than electrical energy while converting any input energy to output electrical energy. Efficiency gives you how efficiently the input energy given is converted to output electrical energy. Efficiency is generally calculated in percentage.
Efficiency of power plant = output energy / input energy = output power / input power.
Power is rate of flow of energy.
In this post we have learnt about electrical energy importance and generation of electrical energy from different power plants.
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