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Energy can be defined as the ability to do work.
A good source of energy would be the one which would:
- do a large amount of work per unit volume or mass
- be easily accessible
- be easy to store and transport and
- be economical
Fossil fuel is a hydrocarbon deposit, such as petroleum, coal, or natural gas, derived from living matter of a previous geologic time and used for fuel.
A power station or a power plant is a facility for the generation of electric power.
A thermal power plant utilizes thermal energy of fuels such as coal, oil, natural gas or radioactive substances for the generation of electric power.
In a thermal power plant the chemical energy stored in fossil fuels or radioactive substances is converted successively into thermal energy, mechanical energy and, finally to electrical energy.
In a hydro power plant electricity is produced from water.
Hydro power plants convert the potential energy of falling water into electricity.
Moving air is called wind Wind
possesses kinetic energyWind energy can be used to sail boats,
grind grains, pump water and generate electricity
Solar energy is the solar radiation that
reaches the earthSolar energy is used for:
- heating water for domestic use
- space heating of buildings
- heating swimming pools
- drying agricultural products and for generating electrical energy
- Biomass is an organic material obtained from plants
and animals
Solar cell is a device that converts solar energy into electricity
A typical solar cell develops a voltage of 0.5-1 Volt and can produce about 0.7 Watt of electricity when exposed to the Sun
A solar cell panel is an assembly of solar cells used to generate electricity.
Solar cells or solar cell panels are used in:
- Artificial satellites and in space probes like Mars orbiters
- Wireless transmission systems or TV relay stations in remote locations
- Traffic signals, calculators and in toys
Tidal Energy, sometimes called tidal power, is the power achieved by capturing the energy contained in moving water in tides and ocean currents.
When tides come into the shore, they are trapped in reservoirs behind dams. Then when the tide drops, the water behind the dam is let out just like in a regular hydroelectric power plant.
The huge moving waves possess kinetic energy. This energy is used to power a turbine. Most wave-energy systems are very small. But, they can be used to power a warning buoy or a small light house.
The energy obtained by converting the solar energy trapped by the ocean into useable energy is known as ocean thermal energy.
The ocean energy plants can operate only if the temperature difference between the water at the surface and water at depths up to 2 km is 293 K or 20 0C or more.
Energy obtained by tapping underground reservoirs of heat, usually near volcanoes or other hot spots on the surface of the Earth is known as geothermal energy.
Nuclear reactions are those reactions where in a nucleus when bombarded with nucleons or other sub-atomic particles; undergoes a change in its composition.
The process of splitting of a heavy nucleus into a number of light nuclei with the liberation of tremendous amount of energy and two or three neutrons is called nuclear fission.
Nuclear fusion is a reaction in which two or more light nuclei combine to form a heavier nucleus releasing an enormous amount of energy:
- Nuclear fusion takes place at a very high temperature of the order of 107 Kelvin
- Hence nuclear fusion reaction is called thermo nuclear reaction
- Nuclear fusion is the type of reaction taking place inside the sun
- Inside the core of the sun fast moving hydrogen nuclei combine to form helium nucleus. Nuclear fusion is the basic principle of the Hydrogen bomb.
A nuclear reactor is a device or a furnace where controlled fission chain reaction is carried out and the energy released is used to generate electricity.
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