Introduction to Energy

We take food for survival and growth of our body. Vehicles like motorcycles, tractors, buses, trucks, ships and aeroplanes require fuel for their running. Even for cooking food we require fuel. What is important which we get from the food or from the fuel? It is the energy.

From the time you wake up to the time you go to sleep at night, energy plays an important role in your life. Energy is important in everyone's life, whether you notice it or not. Without sufficient energy people face difficulties doing their day to day work. All forms of energy including solar energy, light energy, mechanical energy, nuclear energy, and the energy of our body are important to us.

Energy is defined as the ability to do work. We require energy for all types of activities including the activities within our body, with our body or with other bodies. When we say a body has energy, it means that it is capable of doing work.

An engine uses energy of its fuel to move a car along. A battery stores the energy needed to switch on the radio or tape recorder. The heavy flow of water can break the banks of rivers as it also has energy in it. Similarly, the wind also carries enough energy to shake trees.

Importance of Energy in Life

Energy plays a very important role in our lives, providing comfort, increasing productivity and allowing us to live the way we want to. Since the beginning of mankind, we have made use of wood, water, and fossil fuels as a means of heating and making machines work. Almost for all types of activities, we rely on one or another form of energy.

Amount of energy used by a society is an indicator of its economic growth and development. Without energy even our body would be unable to perform basic functions like respiratory, circulatory, or digestive functions. Plants would also be unable to complete the process of converting carbon dioxide, water and minerals into food without the light from the Sun.

Almost all the machines used for the production and manufacture of different types of items would be unable to operate without the use of a source of electrical energy. Nowadays, the electrical energy has become so important that almost in all walks of life electricity is required. For example all electrical appliances in our homes and at our workplace require electricity. All the industries and factories run on electricity.

Various forms of Energy

In daily life we use different forms of energy such as heat energy, light energy, mechanical energy, electrical energy, chemical energy, and sound energy. The most common forms of energy are heat, light and electricity.

As per requirement, one form of energy can be converted into another form of energy by using specific types of devices or processes. We get energy for our daily use from different sources.

Different Sources of Energy

Anything out of which usable energy can be extracted is a source of energy. There is a variety of sources that provide energy for different purposes. For example, coal, petrol, diesel kerosene and natural gas, hydroelectric power, wind mills, solar panels, biomass and so on.

Some of the energy sources can be replenished in a short period of time. Such energy sources are referred to as renewable energy sources, whereas the energy sources that we are using up and cannot be generated in a short period of time are called non-renewable energy sources. Thus, all the sources of energy can be divided into two categories: renewable sources and non-renewable sources of energy.