How long will sources of energy last? I am sure you all must be using electricity judiciously and for those who do not, here comes some advice. We all must ensure careful and judicious use of electricity. For this, we should all take care of the following things in our day to day life:

 

� We must switch off the lights and fans when not in use
� We should turn off the engine of our vehicle at red light
� We all should try to minimize the usage and thus, our dependence on the fuel by several other conservation methods.

 

But have you ever thought why? Why use the source of energy carefully and judiciously? Why not use it as and when we want to? Because our dependence on fossil fuels for our energy requirement is vast. We are using them at a much faster rate than the rate of their formation.

 

Fossil fuels take millions of years to form. Thus, the rate at which they are been consumed will lead to their depletion. Such sources which will get depleted someday are said to be exhaustible or non-renewable sources of energy.

 

On the other hand, there are sources of energy that can be renewed or regenerated. Such sources of energy are called inexhaustible or renewable sources of energy. Renewable energy is available in nature in the form of a continuous or repetitive current of energy. Biomass, sun, water are all examples of renewable sources of energy.

 

We use different sources of energy in our daily life for various activities. On the basis of their use, these sources of energy are grouped into:

 

1. Conventional sources
2. Non-conventional sources

 

Conventional sources of energy

 

The sources of energy used since ancient times that meet a major part of our energy requirement are called conventional sources of energy. Fossil fuels such as coal, petrol, natural gas, wood, wind energy, and energy of the flowing water, that is, hydro energy have been harnessed as potential sources of energy for ages.

 

The growing demand for energy is largely met by fossils fuels such as coal and petroleum.
It takes millions of years for these fossil fuels to form and, also there are limited reserves.
Fossil fuels are nonrenewable sources of energy. Their consumption at such alarming rates would make us run out of these sources of energy soon. Thus, there is a need to conserve and use these resources judiciously.

 

The burning of fossils fuels produces oxides of carbon, nitrogen & sulfur. These oxides are acidic in nature and lead to acid rain which adversely affects our water and soil resources. The combustion of these fuels also leads to increased production of carbon dioxide thus, leading to the greenhouse effect and hence global warming.

 

Besides being used in gas stoves and vehicles, fossil fuels are also used as major fuel in the generation of electricity. For generating electricity, large amounts of fossil fuels are burnt every day in power stations to heat up water for producing steam which further runs the turbine, thus, generating electricity.

 

Non-conventional Sources

 

With technological progress, our demand for energy is increasing day by day. With the demand for energy growing at the current rate, one can�t just depend on the limited and non-renewable reserves of the conventional sources of energy. So, there is a need to look out for new alternate sources of energy. These alternative sources of energy are also known as Non-conventional sources.

 

Some important examples are:

 

1. Solar energy
2. Energy from the sea
3. Ocean thermal energy
4. Geothermal energy
5. Nuclear energy

 

Solar energy

 

The sun has been radiating an enormous amount of energy at the present rate for nearly 5 billion years and will continue doing so for another 5 billion years to come. Of the total energy radiated, only a small part of solar energy reaches the earth�s surface.

 

Energy from the sea

 

Oceans are large water bodies covering 70-80 percent of the earth�s surface. The energy from the sea can be harnessed in three different forms-

 

• Tidal Energy
• Wave Energy
• Ocean Thermal Energy

 

Ocean thermal energy

 

The oceans and the seas are reservoirs of large amounts of solar energy. This solar energy stored in the oceans in the form of heat is called OCEAN THERMAL ENERGY (OTE).

 

Geothermal energy

 

The geothermal energy is the naturally occurring thermal energy of the earth that originates with the rock formation, from radioactive decay of minerals and from solar energy absorbed at the surface.

 

Nuclear energy

 

The energy trapped inside the nucleus of an atom is called nuclear energy or atomic energy. There are two distinct ways of generating nuclear energy. These are:

 

• Nuclear fission
• Nuclear fusion

 

How To Find Good Sources of Energy?

 

We all know that we need the energy to work. But where do we get this energy from? We derive energy from various different sources. Let us have a look at some of these sources of energy. The trains run on energy from diesel. Similarly, we use petrol, diesel, and CNG, that is, the compressed natural gas to run cars, buses, and other heavy vehicles. The energy from electricity is used to light our street lamps.

 

Likewise, we use muscular energy for doing physical work, electrical energy for running different appliances, and chemical energy for cooking food or running a vehicle. All these forms of energies come from various sources.

 

But how do we choose the best source for obtaining energy in its usable form? This question arises several other doubts like:

 

1. Why is CNG preferred over petrol or diesel for running vehicles?
2. Why is kerosene oil or coal not preferred for cooking food?
3. Let us discuss the factors that help in the selection of the source of energy.

 

Selection of a source of energy or fuel depends on many factors such as-
� The amount of heat it releases on burning
� The amount of smoke it produces, and
� Availability

 

Characteristics of good fuels

 

A good fuel is one that produces a large amount of energy per unit mass. This means that a good fuel has a high calorific value. Also, a good fuel must have an adequate ignition temperature. This means that the ignition temperature should not be too low as in the case of white phosphorus or too high as that of wood since it requires a lot of heat or energy to ignite.

 

It should also be pollution-free, thus not producing smoke on burning and also, it should be available easily. Easy storage and transportation is another key factor that determines whether fuel is good or not. LPG is a fuel that exhibits all the characteristics of good fuel, thus is used as an ideal fuel.

 

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