What is energy?
Energy or power is nothing but the ability of the physical system to do work. As per the law of energy conservation, the total energy in the universe is constant but it can be transformed from one form to another by the second law of thermodynamics. Energy can be used to do an everyday activity or to run the machine or to perform specific task or work. The non-zero output is never achieved by zero input.
Types of Energy (Forms of energy)
Energy based on its form can be classified as under:
- Mechanical Energy: Due to motion of object
- Potential Energy: Due to motion of electron in conductor
- Chemical Energy: Due to chemical reactions between various compounds.
- Nuclear Energy: Due to fission and fusion process
- Thermal Energy: Due to temperature or molecular cohesion
Oil if heated in presence of oxygen burns and produce the heat which can be used to heat the water and it gives off steam at higher pressure. If this higher pressure steam can be passed through the turbine, thermal energy of the steam can be transformed to the rotational energy of the turbine shaft and hence generator coupled with it produces electrical power. Hence, Energy conversion takes places in this manner:
Chemical Energy - Thermal Energy - Mechanical Energy - Electrical Energy
Classification of Energy Sources
Energy sources are classified mainly into two types:
1. Conventional Energy Sources (Non-Renewable)
2. Non-Conventional Energy Sources (Renewable)
Conventional Energy Sources (Non-Renewable)
These energy sources are limited in quantity and will be depleted soon. Though these types of energy sources are easily accessed and used but they pollute the atmosphere as well and actively participate in the greenhouse effect.
E.g Petrol, Diesel, Coal, Wood, Oil, Gas etc
These energy sources are infinite in quantity and will be never be depleted. They do not pollute the atmosphere. One of the main disadvantages is the technology to use these sources is still in developing phase and is very costlier.
E.g Solar energy, Tidal energy, Wind energy, Geothermal energy.
Learn about thermodynamics