Non-Conventional Sources of Energy

Can you picture driving a car that is powered by water? Or one that is powered by the Sun? The fact is that you may have to become used to such outlandish thoughts. Conventional fuels are increasingly running out, while non-conventional energy sources are becoming our future. And, in order to run them, let us study more about non-conventional energy sources. 

Energy is a critical component of the economic infrastructure, as it is the primary input required to support economic growth. Economic development and energy usage have a close relationship. The greater a country’s per capita energy usage, the more developed it is, and vice versa. Human civilization is reliant on a variety of energy sources. In this article, we will discuss the non-conventional sources of energy and their usage, advantages, and disadvantages. Before, that let’s first understand what is energy?

What is Energy?

The term ‘Energy’ refers to the capacity or ability to do work. Kinetic energy, electrical energy, thermal energy, potential energy, chemical energy, nuclear energy, and other types of energy exist. All sources of energy are related to motion. Kinetic Energy, for example, is connected with any moving object or body. 

Energy, according to the principle of conservation of energy, or the fundamental rule of thermodynamics, cannot be generated or destroyed, but can only be transformed from one form to another. 

There are two primary sources of energy: Conventional sources of energy and Non-Conventional sources of energy.

Conventional Sources of energy- The sources of energy that are in use for long periods of time by humans and once finished cannot be replaced quickly are called conventional sources of energy. For example Coal, petroleum, etc.

Non-Conventional Sources of energy- The sources of energy that are continuously replenished in nature and are widely available. They are called non-conventional because till now they are not used extensively in our daily life. These sources of energy also do not cause pollution. For example Solar energy from the sun, wind energy from the winds, tidal energy, Bio-gas, and so on.  

Let’s discuss the Non-Conventional sources of energy more deeply as:

Non-Conventional Sources of Energy

The Sun is the ultimate source of energy on our planet and all other examples that are mentioned above are obtained either directly or indirectly from the sun. For example, the wind energy that we obtain from the winds and the winds are produced by the unequal heating of two different regions of the surface of the earth. Thus, we can use these sources of energy till our earth receives light from the sun, which is there for the next millions of years. This is also the reason why non-conventional sources of energy are also called renewable sources of energy as every day these energies are getting renewed in nature.

Non-conventional sources of energy, often known as renewable sources of energy, are energy sources that are continually renewed by natural processes. Non-conventional energy sources are not quickly depleted and may be created at a consistent pace for repeated usage.

Tidal, Wind, Solar, Nuclear, Biomass, and other natural resources geothermal energy, are referred to as “non-conventional resources.” Because they are pollution-free, we can use them to generate clean energy with minimal waste.

Furthermore, these energy sources are less expensive and do not contaminate the environment or natural surroundings. They are also known as renewable energy sources since they may be created or created through natural processes at a rate greater than or equal to the rate at which they are used.

Lets discuss each example of non-conventional sources of energy with their examples, advantages, disadvantages as:

Tidal Energy

Before knowing what is tidal energy, let’s first understand what are tides? Tides is the periodic movement of the ocean waters due to the gravitational force of the moon and the sun. Tides are of two types – high tides i.e the rise of water and low tides i.e the fall in the level of water. Since it is caused due to the sun and the moon’s gravitational effect, tidal energy is called renewable energy.

Tidal energy is the energy possessed by the rise and fall of water during high and low tides. The tidal energy can be processed to electricity by building dams across the narrow openings of the sea.

The tidal energy from tides are obtained and used to generate electricity using a machine called Tidal Energy Generator. Tidal barrages or dams are built over a limited sea entrance. When the sea level rises, water pours into the dam. This causes the turbine blades, which are connected at the dam’s entrance, to shift. As a consequence, power is generated.

Tidal Energy obtained by Tidal energy generator

Advantages of Tidal Energy

Some advantages of tidal energy are:

1. Tidal energy is a renewable energy source, which implies that it does not deteriorate as it is consumed.
2. Tidal power plants, in addition to being a sustainable energy source, do not release greenhouse gases during electricity generation.
3. The tidal currents are quite predictable. Low and high tides follow predictable patterns, making it easy to predict when electricity will be generated throughout the day.
4. Tidal power plants are capable of producing large amounts of electricity. One of the key reasons for this is because water is extremely dense – over 800 times denser than air.
5. Also, the system established to obtain tidal energy has low operational and maintenance costs.

Disadvantages of Tidal Energy

Some disadvantages of tidal energy are:

1. The possible installation location must fulfill extremely precise conditions in order for a tidal power plant to be developed. Because they must be positioned on a coastline, possible station locations are limited to coastal states.
2. Because of the high density of water, tidal energy turbines must be substantially more robust than wind turbines. The cost of building a tidal power producing facility varies based on the technology used.
3. The fact that tidal energy is renewable does not imply that it is fully ecologically benign. The development of tidal energy power plants can have a significant influence on the surrounding ecology.
4. While tidal power generates predictable power, it does not produce steady power. We can predict when the tidal power plant will create electricity, but that output may not match the demand for energy.

Wind Energy  

The energy obtained from the wind is called wind energy. The wind contains kinetic energy which can used to harness energy by converting it to mechanical energy by the use of windmill. Although, wind energy has been used by us for a long time, it was used in propelling the sails of the ship in the ancient times.

Advantages :

i. Like solar energy , it is also a renewable form of energy.

ii. It does not cause any air pollution and global warming by releasing harmful gases.

iii. It is space efficient and requires very little space on the land surface and the land between two windmills can be used for agriculture and other different purposes.

Disadvantages:  

i. It is very location specific as wind mills cannot be setup in all places. It can only be installed at places where there is strong winds

ii. It is very costly to setup and difficult for repair.

iii. Storms and cyclones cause great damage to windmills.

Now having understood the advantages and disadvantages of wind energy, let’s understand the working of a wind mill and how it produces energy.

A windmill is tall tower like structure having blades (mostly three). Under the influence of winds , these blades rotate and these rotate the coil connected to the blades. This coil is placed between North and south pole of the magnet which acts as electric generator and produces electricity.

Solar Energy

The sun is the biggest source of energy that we have, it’s radiating very high energy constantly for very long time and will continue to do so. The energy we obtain from the sun is called solar energy.  

Solar energy can be harnessed using several devices like solar cooker and solar panel.

Solar Cooker

We all know that a black surface absorbs most of the energy that fall on it and reflects back very less amount of it. This principle used by solar cooker and solar water heaters. In addition to it, some solar cooker use heater to focus the sun rays at a particular point for more heating. Also the cookers are covered with a glass plate, can you guess why? It’s because of the green-house effect as the glass plates traps the sun’s heat inside the cooker.

Disadvantage of solar cooker: The solar cooker can only function when there is sun’ heat , it cannot store the solar energy for reuse.

Solar Panel

The disadvantage of solar cooker is overcome by the use of solar panel. A solar panel is a collection of solar cells. A single cell can produce a voltage of about 0.5-0.9 V and can produce a energy of 1.5 W.  

Advantages:  

i. They need no maintenance and last for about  25 years.

ii. They can store solar energy in the form of electricity and can be reused in several ways.

iii. They are very important source of energy for space missions as all the orbiters , satellites use solar energy.

Disadvantages:

i. The solar cells are made up of silicon. Though , it is available in abundant quantity but high-grade silicon is very expensive, therefore the cost on setting up becomes very expensive.

The solar energy is also crucial for our survival. This is because without solar energy plant cannot do photosynthesis and thus there would be no food left.

Advantages of solar energy:

i. Solar energy is available to us in infinite amount. Since, sun will be there and will continuously emit energy for the next few hundred million years.

ii. Solar energy can protect the nature and reduce global warming. Solar energy is a green form of energy which can be converted to electricity and used in different energy and this process of creating electricity is much cleaner than from burning coal which emits harmful gases into our atmosphere.

iii. Solar devices (like solar panels and solar cookers) though expensive now are one time investment and saves a good amount money in long term.

iv. Proper harnessing of solar energy is also a very crucial aspect of our space exploration as the artificial satellites and other orbiters that we sent on outer space and different planets operate using solar energy.

Wind Energy  

The energy obtained from the wind is called wind energy. The wind contains kinetic energy which can used to harness energy by converting it to mechanical energy by the use of wind mill. Although, wind energy has been used by us for a long time ,  it was used in propelling the sails of the ship in the ancient times.

Advantages :

i. Like solar energy , it is also a renewable form of energy.

ii. It does not cause any air pollution and global warming by releasing harmful gases.

iii. It is space efficient and requires very little space on the land surface and the land between two windmills can be used for agriculture and other different purposes.

Disadvantages:  

i. It is very location specific as wind mills cannot be setup in all places. It can only be installed at places where there is strong winds

ii. It is very costly to setup and difficult for repair.

iii. Storms and cyclones cause great damage to windmills.

Now having understood the advantages and disadvantages of wind energy, let’s understand the working of a wind mill and how it produces energy.

A windmill is tall tower like structure having blades (mostly three). Under the influence of winds , these blades rotate and these rotate the coil connected to the blades. This coil is placed between North and south pole of the magnet which acts as electric generator and produces electricity.

Geo-thermal Energy

Geo-thermal energy is the heat energy possessed by the rocks inside the earth. The places where the rocks inside the hot is very hot are called hotspot.  

Now, the heat of these rocks heats up the underground water and turns it into steam. This steam is extracted by drilling hole into the ground and connecting pipeline to rotate the turbine with the help of the steam and produce electricity for use.  

In India, only one place is Madhya Pradesh has a hotspot . But in US there are a no. of geo-thermal power plants. The Pacific ring of fire is also a suitable spot for geo-thermal energy sites.

Advantages:

i. They are renewable and completely environment friendly.

ii. They are also energy of future and new research to harness geothermal energy more efficiently is going on in different parts of the world.

Biomass Energy

First understand what is Biomass? The waste and the dead remains of living animals , plants  is called  bio-mass. They contain carbon compounds. The chemical energy stored in them is called bio-mass energy. This form of energy being used by humans from the very early age. Humans burn wood and cattle dung for cooking for a very long time and is continuing till this date. But this method is not very beneficial as it releases harmful gases into the atmosphere.

A much more advanced and efficient use of biomass is the production of bio-gas from biomass. The bio-gas is produced by the decomposition of biomass in the absence of oxygen. Bio-gas contains nearly 60% methane and rest is carbon dioxide , hydrogen and hydrogen sulfide.  

Bio-gas is produced in a large dome shaped plant also called bio-gas plant. In India, however, these plants are called Gobar Gas plant because the main item form which the bio-gas is produced here is cow dung( also called gobar in native language).  

Advantages:

i. It is an efficient technology which produces fuels from our wastes.

ii. It reduces our dependencies on fossil fuels as bio-gas produced from biomass plants can be directly used as fuel

iii. It is very cost effective and cheap.

iv. It is carbon neutral. Carbon dioxide is released on burning bio-waste but no carbon is released into the atmosphere on burning bio-fuels like bio-gas etc.

Disadvantages:

i. It releases methane in the environment which causes greenhouse effect and global warming.

ii. It is not as effective as fossil fuels.

iii. Building of bio-gas plant requires a lot of space.

Nuclear Energy

Nuclear energy is the energy produce when one heavy nucleus splits into two light nuclei or two light nuclei fuses to one heavy nucleus producing enormous amount energy in form of heat and light.  

Nuclear reaction are of two types :

i. Nuclear Fission  

ii. Nuclear Fusion

Nuclear Fission- The process in which one heavy nucleus (e.g uranium , polonium) splits into two light nuclei producing large amount of energy and neutrons along with it.

Nuclear Fusion- The process in which two light nuclei fuses into one heavy nucleus at a very high temperature and pressure, producing large amount of energy.

In both the reaction, the origin of energy is loss in mass, the sum of the products is less than the sum of the products. The loss in mass in converted into energy according to Einstein’s mass-energy equation, E=mc2.

Though, nuclear reactions produces large amount of energy, but they are uncontrolled and can cause explosions.

But we humans, till now can only control the fission reaction. Inside the nuclear reactor, fission reaction occurs under controlled condition which produces heat which is used to produce steam to rotate the turbine to produce electricity.

Nuclear Fission Reaction

We have seen the definition of nuclear fission which says that in fission reaction, one heavy nucleus splits into two light nuclei and produces high amount energy and neutrons along with it. These neutrons goes and hit the other atoms of Uranium (or plutonium) and thus the chain reaction continues and each of this reaction emits a huge amount of energy in form of heat and light. This is the reason why nuclear reactions are uncontrollable. Now , let’s understand how electricity is being produced by the nuclear power plant.

Advantages of nuclear energy:

i. Nuclear energy is a green source of energy which does not produces any harmful gases .

ii. The amount of energy obtained from a single nuclear reaction is very high.

Disadvantages:

i. Nuclear reactions are very hard to control, as they are chain reactions and even a slight mistake can cause huge risks.

ii. The elements used in the reaction are radioactive and the radiation can cause severe health issues like cancer and other genetical deformation.

iii. Unfortunately, this is also used in nuclear weapons. An atomic bomb is based on nuclear fission reaction where the reaction is uncontrollable. It was used two times in World War2 and cause the deaths of millions of people.

To date, we cannot control fusion reactions.  

Nuclear fusion occurs inside the sun where two hydrogen atoms are combined to form one helium atom which in process produces huge amount of energy.

Sample Problems 

Problem 1: What are the conditions for a source of energy to be good source of energy?

Solution:

A source of energy is considered to be good source of energy if,

• Easily accessible
• Easy to store and transport
• Economical

Problem 2: Can any source of energy be completely pollution free? Why and why not?

Solution:

No, any source of energy cannot be totally pollution free. This is because the process of producing energy may not cause pollution, but the production of devices required may cause pollution. Like solar energy is green but the making of solar cells cause pollution. Likewise, nuclear energy may not cause pollution but the e-waste generated after the fission reactions are harmful and cause health hazards. Still, they are much cleaner than non-renewable energy sources like fossil fuels, coal etc.

Problem 3: Name and define the process used for producing electricity using nuclear energy.

Solution:

The process used for producing electricity from nuclear energy is Nuclear Fission.

Nuclear Fission: Nuclear Fission is the process in which one heavy nucleus splits into two light nuclei of almost equal mass and producing enormous amount of energy in the form of heat and light.

Problem 4: State two advantages and limitations of producing electricity from solar energy.

Solution:

Advantages of solar energy:

• It is a green source of energy as it causes no pollution to the environment.
• It is widely available and will lasts for millions of years, and therefore it is more reliable form of energy rather than fossil fuels and coal.

Disadvantages of solar energy:

• The cost of solar panel is too high, so all cannot afford it.
• Installation of solar panels requires a lot of open space which receives good sunlight. Thus, it cannot be set up anywhere.

Problem 5: Why is the wood as a fuel not advisable, although wood is considered to be a renewable source of energy?  

Solution:

The use of wood as fuel is not advisable because:

• Forests once lost in the extraction of wood takes about 15-20 years to restore, which is quite a long period of time. Thus, the wood once lost cannot be renewed immediately.
• The burning of wood releases several greenhouse gases like carbon dioxide and methane which causes greenhouse effect and the smoke causes air pollution.

Problem 6: How all the living beings on our planet are dependent directly or indirectly on our sun for survival?

Solution:

Sun is called the ultimate source of energy in our planet because plants require sunlight to produce food using photosynthesis. Now, this process has two crucial importance, first, it provides all the animals in this planet including us food, secondly, it releases oxygen which is the life –supporting gas for the survival of all living beings. Sun also heats our planet which is creates a suitable temperature in our planet for living. Sun’s heating is the cause of winds and waves in our planet. Sun’s gravitational pull causes tides which is an important part of our ecosystem and also an important renewable source of energy. Thus, it is very clear that we all depend on sun directly or indirectly for our survival.