Non-renewable Energy - Types, resources advantages and disadvantages

We all ride bikes or cars and obviously we should have our driving licence if we are driving it, not the passenger! How do the bikes, cars or the automobiles at large work? Also, we get electricity at our homes or everywhere where it is needed. How are we getting this electricity? All we get are from the natural energy resources that are present in our nature. Some natural energies are renewable and some are non-renewable. What is non-renewable energy, what are the types of non-renewable energy and where from it is sourced, advantages and disadvantages, all will be discussed in this topic.

Table of content

• Definition of renewable energy and the resources
• Non-renewable energy
• Types of Non-renewable energy
• Non-renewable energy resources
• Advantages and disadvantages
• Practice problems
• FAQs

Definition of renewable energy and its resources

The energy produced from the natural resources which can be replenished to produce useful energy again is called renewable energy. The natural resources that provide renewable energy are known as renewable energy resources like sunlight, wind, ocean tides, biomass, etc.

Type of renewable energy:

1. Wind energy
2. Biomass energy
3. Tidal energy
4. Geothermal energy
5. Solar energy
6. Hydro-energy

Non - renewable energy

Non-renewable energy is defined as the energy derived from sources that are either already depleted or cannot be quickly restored. Fossil fuels (such as coal, oil, and natural gas) and nuclear fuels are the most prevalent sources of this energy. Fossil fuels take a very long time (about 300 million years) to restore or to create.

Types of Non-renewable energy

1. Fossil fuels
2. Nuclear fuel

1. Fossil fuels: Fossil fuels are one of the forms of natural energy resource that are formed by the decomposition of buried organic materials like trees, animals etc, underneath the Earth's surface.

Formation process: Over millions of years, the decomposed materials are buried deep beneath the Earth’s surface and are subjected to pressure and heat in the Earth's crust.

Coal, petroleum, and natural gas are the main carbon-rich fuels that makeup fossil fuels.

Formation process of fossil fuels

Fossil fuels need to be extracted from the Earth and then it has to be processed for our use.

2. Nuclear energy of fission: The energy produced during the nuclear fission in a power plant is known as nuclear energy of fission. The most famous nuclear fuel is Uranium. Same as fossil fuels, nuclear resources are also present underneath the Earth as minerals and that have to be extracted and then have to be refined and processed for use as fuel.

Non-renewable energy resources

There are multiple examples of non-renewable energy resources present in front of our eyes. Some of them are mentioned below.

1. Coal: Coal rock is dark or brownish. Coal is a type of fossil fuel that is burnt to produce heat energy. Coal is formed by the decomposition process of organic materials like trees, and plants over millions of years. Under tremendous pressure of the earth’s crust, they are excellent carbon-rich. Coal is ranked according to the level of “carbonisation” it has gone through. Carbonisation is the process through which organic material is passed to become coal. About 10 feet (3 metres) of solid vegetation needed to be crushed together to form 1 foot (0.3 metres) of coal.

2. Petroleum: Petroleum is a type of fossil fuel that is typically found in a liquid state. Crude oil is the raw form of petroleum. This energy resource is usually trapped in the rock formations far beneath the surface of the Earth. Deep drilling is used to extract the oil, which must be refined to petroleum before usage.

3. Natural gas: Natural gas is one more type of fossil fuel that is found underground in natural reservoirs far beneath the Earth, trapped between rocks. The major component of natural gas is “Methane”. When it is extracted, it has to be processed for our use. After processing the energy produced by this natural gas is subsequently used for heating, cooking, and other purposes. Liquid natural gas, or LNG, is the name given to this natural gas when it is cooled down to a liquid state. The cooling is done by pressurising the natural gas till it reaches the liquified state. This process provides easy access to transportation of natural gas with safety.

4. Uranium: Uranium is a type of nuclear fuel which is present in the rocksalt formations beneath the Earth. Uranium in its original form is not a usable product as an energy source and has to be refined after extraction. Since uranium releases a large amount of energy in a very small time window and also, it is very highly radioactive in nature therefore in order to produce the energy from uranium, a huge and safe power plant is required which is known as the nuclear power plant.

Advantages and disadvantages

Advantages:

1. Non-renewable energy resources are easily accessible and compatible.
2. It is affordable
3. Like fossil fuels when it is extracted from the Earth, there are multiple types of useful compositions we get. For example, petrol, diesel, and LPG gas can be used according to various demands.

Disadvantages:

1. It can not be reused after exhausting it.
2. Non-renewable energy resources take a very long time (millions of years) to form.
3. The byproducts of non-renewable energy are responsible for the degradation of the environment of the Earth. It causes global warming which affects the melting of ice on the glaciers and in the poles which causes a rise in sea water level.
4. The byproducts of non-renewable energy are also responsible for the shifts in the monsoon that affects the farming of various crops.
5. Sometimes it is very dangerous to handle and transport non-renewable energy from one place to another (like nuclear fuel, petrol, diesel).
6. Exploration and extraction of non-renewable energy resources like mining of coal, the drilling process and also preprocessing stages are very much infrastructure-heavy and dangerous.
7. Extraction of resources like coal is very harmful to human health since it emits carbon dioxide and carbon monoxide and too much dust which causes respiratory issues like silicosis in human bodies who are working in those mines and also for those who are staying near coal mines.

Practice problems

Q1. How is energy extracted from fossil fuels?

A. “Coalification” is known as the formation of fossil fuels in which the decomposition of the dead trees and plants happens and eventually leads to the formation of fossil fuels. This process takes millions of years. The coalification process is done far beneath the Earth in which the decomposed organic materials are compressed due to the weight of the Earth's layers above it. The temperature beneath the Earth’s surface is very high which plays a key role in the formation of fossil fuels.

Q2. Explain the basic working of the nuclear power plant.

A. Working principle: A nuclear power plant is based on nuclear fission. Nuclear fission is the process of splitting an atom into lighter nuclei during a nuclear reaction that produces a large amount of heat. This heat is used for further processes in order to produce electricity.

Nuclear power plant: A nuclear power plant is a power generation system which uses nuclear fuel like uranium as its working fuel. It consists of various parts such as core, moderator, control rods, coolant etc which will be discussed below. The pictorial representation of a nuclear power plant is given below.

Fuel rods: Fuel rods are basically uranium rods (${ }_{92}^{235}U$). Pallets of uranium oxide (UO₂) are used to create the fuel rods.

Core: The core is used to protect the environment and human lives from nuclear radiation produced in the nuclear reaction. It is usually a very thick (of a few metres) wall made up of cement and steel materials which surround the nuclear reaction stage and the steam generator.

Moderator: There is material in the core that slows the neutrons emitted during fission so they can continue to cause fission in a controlled manner. Water can be used, however, heavy water or graphite is more suitable in the power plants as moderators.

Control rods: The control rods are used to control the chain reaction in the nuclear reactor. These are introduced into or removed from the core to regulate the rate of the reaction or even to stop it. They are made of neutron-absorbing materials like Cadmium, Hafnium, and boron.

Coolant: Coolant is basically used to extract the energy released during the reaction in the reactor. A fluid (water or CO₂) circulates through the core in multiple loops to absorb the heat which will be used to generate the steam. Since the energy released during the chain reaction is very high, the fluid which is used to absorb the heat should have a very high specific heat capacity.

Q3. Write the difference between renewable and non-renewable energy?

A.

Q4. What do you mean by the direct source of renewable energy and non-renewable energy?

A. If we talk about the direct source of renewable energy, one example is the Sun. The Sun is present in our solar system for a long time and is able to live for millions of years to come and can provide energy for our solar system and hence to the Earth. This energy is essential to run lives on the Earth. If we talk about the direct source of non-renewable energy, one example is fossil fuels, since they are already present beneath the Earth. But fossil fuels are very limited in amount so these have to be used conveniently. The non-renewable energy sources are not replenished from time to time.

FAQs

Q1. Why do we need to regulate the use of non-renewable energy resources?

A. Non-renewable energy resources are available in a very limited amount as compared to renewable energy resources. These resources are cost-effective, economically viable and easily accessible to us. Therefore we need to use the non-renewable energy resources in a sensible manner.

Q2. What are the disadvantages of fossil fuels?

A. The disadvantages are as follows:

(a) There are several contaminants created by burning coal and petroleum which contribute to groundwater and soil pollution.

(b) Burning fossil fuels releases gases like carbon dioxide which contributes to global warming and air pollution.

(c) Fossil fuels are formed over millions of years but presently, the use of fossil fuels is at a very high rate and increasing day by day. Therefore the resources are depleting.

(d) Acid rain, which is caused by the emission of carbon, nitrogen, sulphur, and other oxidants due to the burning of fossil fuels, has an impact on soil fertility and potable water.

Q3. All non-renewables are fossil fuels. Is this statement correct?

A. The statement is wrong because fossil fuels are one of the types of non-renewable energy resources. The other type can be nuclear fuels. Therefore we can say that all fossil fuels like crude oil, natural gas and coal are non-renewable energy resources but all the non-renewable energy resources are not fossil fuels.

Q4. Why is it necessary to control the nuclear reaction in the nuclear reactor?

A. We know that nuclear fission is a chain reaction which keeps on increasing and as the chain reaction increases the energy produced in nuclear fission will increase continuously. But the nuclear reactor has its safety limitations. Therefore the nuclear chain reaction needs to be controlled. By having control over the nuclear reaction, we can produce the power according to our needs.