Source of Energy


Various types of energy sources are there that can be divided into different parts. The sun is not only the source of energy. Geothermal energy, nuclear energy, biomass, wind energy, and petrol are some of the other important sources from which energy can be extracted. Based on the characteristic of sustainability, energy is classified into two main types of energy sources. Energy can be extracted from both renewable and non-renewable sources. Conventional and non-conventional sources of energy are two other types of energy sources that play an important role in the consumption and usage of energy.

Classification of Energy

Energy can be classified as the core ability to do any work. The ability of a particular system to perform any task is regarded as energy. Energy is such a property, present in an object that can be transferred into various objects (Leung et al. 2020).

Energy can also be converted into different forms. Another example of chemical energy is a candle in which the energy is stored as a form of chemical energy and it has to be burnt to extract this energy (Golubev et al. 2021).

Burning is such a process with which any kind of chemical energy can be converted into heat energy.

Renewable and non-renewable sources of energy

The two most important sources of energy are renewable and non-renewable energy. Natural resources of energy such as geothermal, solar, wind, tidal, hydropower, and biomass energies are renewable energies that are sustainable in nature (Babenko et al. 2019). These energy sources are safe for the environment.

Figure 1: Energy Sources

Non-renewable sources of energy are limited in supply. This type of source of energy is mainly based on earth and possesses a limitation with which it can be finished (Afrah et al. 2019). Natural gas, hydrocarbon gas liquids, petroleum, coal, and nuclear energy are some important examples of non-renewable energy.

Figure 2: Generation of renewable energy globally

In recent times, the global usage of renewable energy has increased very much. Wind power and hydropower consumption and generation have also increased from before.

Difference between renewable and non-renewable sources of energy

Renewable energy sources
Non-renewable energy sources
These energy resources are not impacted by any human activity 
Human activities, directly impact non-renewable energy sources
These sources can be replaced and renewed. 
Once consumed, these sources cannot be renewed.
Sources are inexhaustible in nature 
These sources are exhaustible in nature. 

Table 1: Difference between renewable and non-renewable sources

Other types of sources of energy

Name of the energy source
Wave energy 
Less damage to the land, widely available and abundant 
Suitable for a certain location, visual pollution and noise, dependent on the length of wave that can differ from time to time
Solar energy
Enhahcne technological development, reduce maintenance costs and electricity bill 
Dependent on weather, spacious, expensive
Tidal energy
Predictable, longevity and continuous supply 
High cost in construction and negative impacts of EMF emission
Wind energy
Cost-effective and environment-friendly
Threat to wildlife and aesthetic pollution
Nuclear power energy
Lessen emission of greenhouse gases and less expensive 
High-risk pollutant for water and harmful for animal lives and trees
Biomass energy
A great revenue source for manufacturers, carbon-neutral 
High chances of deforestation 
Hydrogen energy
Reduces harmful emissions and fuel-efficient
Storage difficulty, high flammable and expensive
Geothermal energy
Highly efficient and easy maintenance 
Lack of sustainability and high investment cost 
Hydroelectric energy
Adjustable and reliable with emission-free
High risk of flood with high initial cost and high emission of methane and carbon

Table 2: Different sources of energy with advantages and disadvantages

Two types of natural sources of energy

As time moves forward, the natural sources of energy have been changed accordingly. Good sources of energy may consist of some significant characteristics among which easy transportation, high economic value, and less polluting attributes are important (Malav et al. 2020). Natural sources of energy are divided into two types, conventional and non-conventional energy sources. Conventional energy sources are being used for a long time and these are well-known and introduced sources of energy (Ranjith & Naik, 2018). Non-conventional sources of energy are introduced just a few years back and are developing day by day. Petroleum, coal, and natural gas are examples of conventional sources. Biogas, solar and geothermal are examples of non-conventional energy sources.

Figure 3: Conventional source of energy

Difference between conventional and non-conventional sources of energy

Conventional energy source
Non-conventional energy source
Exhaustible in nature 
Non-exhaustible in nature
Expensive for proper maintenance and transmission 
Less expensive and easy to maintain 
Prone to pollution 
Pollution-free and environment-friendly 

Table 3: Difference between conventional and non-conventional energy sources


One most important characteristic of energy is that it cannot be created as well as destroyed. Different sources of energy may include thermal energy, chemical energy, nuclear energy, and electrical energy. Energy can also be get as a form of electromagnetic radiation such as light. In food, the energy is stored as chemical energy and the human body collects this energy by consuming food.


Q1. Which sources of energy are regarded as helpful for commercial purposes?

Natural gas, coal, and petroleum oil are three main energy sources, used for commercial purposes. The usage of these sources is developing day by day.

Q2. What are the four most important non-renewable sources of energy?

Mineral oil, coal, natural gas, and thermal energy are four important sources of non-renewable energy. These sources are limited in nature that cannot be fulfilled after some time.

Q3. What is the significance of non-conventional energy sources?

This type of energy source is pollution-free and renewable is one of the most important requirements of recent times. These are easily available and another advantage of non-conventional energy sources is.

Q4. Which source of energy is considered the largest energy source all over the world?

Oil is the most important and largest source of energy all over the world. This source is a dominant source as well that plays an important role in transporting system.



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