In nature the energy is available in various forms which can be converted to the electrical energy. The following are the various common sources of electrical energy.
Fossil Fuels
Fossil fuels are the main source of the electrical energy in the world. The fuels used are coal, oil and gas of which the coal is the most widely used fuel. The thermal energy in the fuels is converted into the mechanical energy with the help of turbines and these turbines run the electric generators to convert the mechanical energy to
electrical energy. The initial cost of the generation is comparatively lower than the other types of sources but the cost of the generation is high due to the cost of the fuel. The generation with the fuels is unclean especially using the coal as fuel involves a lot of dirt. The fossils fuels also create pollution to the environment.
electrical energy. The initial cost of the generation is comparatively lower than the other types of sources but the cost of the generation is high due to the cost of the fuel. The generation with the fuels is unclean especially using the coal as fuel involves a lot of dirt. The fossils fuels also create pollution to the environment.
Water
The electric power generation with water is called as hydroelectric power. The water is stored at a suitable altitude to create a certain head with the help of constructing dams across the river. Thus the potential energy stored in the water is converted to kinetic energy and this mechanical energy is converted to electrical energy at a lower altitude. The initial cost may be high due to construction of the dam but the running cost is very low. The hydroelectric power is clean, environmental friendly and emit no emissions.
Nuclear
The radioactive materials like uranium, thorium can be used to generated electricity. The heat energy liberated by the fission reaction of the radioactive materials is converted to electricity. The heat produced by a kilogram of radioactive materials is equivalent to the heat produced by 4500 tonne of coal. The initial cost of nuclear plant is very high and it has difficulty in disposal of nuclear wastes. Added to this there is also a lack of sufficient trained personal to handle the nuclear plants.
The Sun
The sun is the primary source of energy for the earth and the electricity can be generated by using this solar energy. The solar energy can be converted into electrical energy by two ways either by solar thermal energy or by direct conversion. The former method can be done by tapping the heat energy by using multiple reflectors to focus all the sun's radiation over a small area and then converting the heat energy in to mechanical and hence the electrical energy. The direct conversion can be done by the use of PV cells which convert the light energy directly into the electrical energy in the form of DC. The major drawback is that the cost and area required is higher and doesn't work at night and during cloudy days.
Wind
In the areas where the winds are steady and flow for considerable amount of time, the wind energy can be used to run the windmill which in turn drives the generator to convert it into electrical energy. There is negligible maintenance cost for wind generation but these suffer from certain disadvantages such as variable output due to variation in winds and very small amount of power generation.
Other Sources
Apart from the above mentioned electrical sources there are other sources which supply electricity.
Batteries: Batteries convert the chemical energy into electrical energy.
Energy from the oceans: In oceans the tidal can be energy is used to generate electricity. Apart from this there are Ocean Thermal Energy Conversion (OTEC) systems which generate electricity by using the temperature difference from the deep sea to the surface.
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