Sources of Energy - Class 10th Science
Introduction
Capacity of doing work is called energy. We use our muscular energy to do many works. Apart from that we use many natural sources of energy, for example burning of wax is used in candle to get light. Burning of diesel or petrol is used to run vehicles.
One form of energy can be converted into other form, for example to lit an electric torch we convert chemical energy into light energy.
There are many sources of energy we have, such as fossil fuels, wood, solar energy, wind energy, water energy, etc. which we use to make our life comfortable.
What is a Good Source of Energy?
We cannot use all sources to get energy effectively. There are some parameters which decide that which source of energy is good. These are
- Source of energy which would do a large amount of work per unit volume or mass
- Source of energy which can be easily accessible
- Source of energy which can be easy to store and transport
- Source of energy use of which is economical
Thus, source of energy which can do a large amount of work per unit volume or mass, can be easily accessible, can be stored and transported easily and is economical in use is called a good source of energy.
Conventional Sources of Energy
Fossil Fuels
Many millions of years ago living organisms, such as trees and plants, got buried. Over the time period because of anaerobic decomposition dead organisms were converted into forms sources of energies. These sources of energy are called FOSSIL FUELS.
Coal, petroleum and natural gases are example of fossil fuels. Today human depends almost completely on these fossil fuels to get energy.
Coal and petroleum is the most important and widely used fossil fuel today. Our technologies were also developed for using these energy sources, i.e. coal and petroleum.
Fossil Fuels and Non-Renewable Sources of Energy
Fossil fuels were formed over millions of years ago and there are only limited reserves of them. Since, fossil fuels take millions of years to form, thus these are called non-renewable resources of energy.
With the increase in population demand of energy is increasing. To fulfill this demand of energy we are almost completely depend on fossil fuels. If we were to continue consuming these sources at such alarming rates, we would soon run out of energy resources, i.e. out of energy. So, we must conserve these resources of energy.
Disadvantages of use of Fossil Fuels
There are many disadvantages of getting energy using of fossil fuels.
- Burning of coal, petroleum and petroleum products release many harmful gases, such as oxides of carbon, nitrogen and sulphur.
- These acidic oxides in the form of gases go in atmosphere and lead to acid rain. Acid rain makes our water bodies acidic which is threat to survival of aquatic organism.
- Acid rain makes our soil acidic which affects yield of agriculture produces badly.
- Harmful gases emit because of burning of fossil fuels make air polluted and creates many problems, such as green house effect.
- Breathe in polluted air creates many health problems
Power Plant
Plants to generate electricity are generally called power plants. In a power plant, energy is used to rotate huge turbines attached to electric generator. Electric generator converts mechanical energy into electrical energy. Electricity generated by power plant is transported to different places, such as house-holds, factories, markets, etc. for further use.
The transmission of electricity is more efficient than transportation of coal, petroleum, or other resources of energy. Thus, these power plants are set up where resources of energy are available.
There are many types of power plants depend on resource of energy use in them.
Thermal Power Plant
Power plant in which coal is used to produce electricity is called THERMAL POWER PLANT. Since, in such plants fuel is burnt to produce heat energy which is converted into electrical energy, thus these are called Thermal Power Plants.
In thermal power plant coal is used to heat water, and steam so produced is used to rotate huge turbines attached to huge electric generators.
Electricity produced in thermal power plants is transmitted to different places through electric wires for further use.
Advantages of Thermal Power Plants
- Coal is used in thermal power plants which is cheaper than other fuels
- Mechanism used in thermal power plant to run turbine is comparatively simple
- Thermal power plants requires less space compare to hydro electric power plants
- Heat produced in thermal power plants can be reused
Disadvantage of Thermal Power Plants
- Thermal power plants produce huge amount of carbon dioxide which pollute atmosphere badly.
- Produced carbon dioxide from thermal power plants is responsible for acid rain and green house effect.
- Thermal power plants produce large amount of ash due to burning of coal, which spread surrounding area of the power plants and make agriculture land barren.
- Thermal power plants are less efficient than others.
- Requires huge amount of water to produce steam, thus should be set up near the river sites.
- Coal is used as fuel in thermal power plants. Handling of huge amount of coal requires large space.
- Disposal of ash produced after burning of coal also requires large area
- Efficiency of thermal power plants is comparatively very less, which is only about 30% to 35%.
- Operation cost of thermal power plants is higher than hydro electric or nuclear power plants.