Energy is an important part of our lives. We use it daily to do the things that we enjoy like cooking, walking, working, and powering up our smartphones. There are different types of energy such as radiant, heat, sound, gravitational, etc. All these energies are around us and have a huge importance in our life.
All those types are grouped under two types of energy: kinetic and potential energy. Before we go into the detailed study of different types of energy, it is important to know the different ways in which energy sources can be classified. They are
- primary and secondary
- commercial and non-commercial
- renewable and non-renewable.
Let us discuss them in detail.
Primary and secondary energy
Primary energy is the energy that is found in nature. They appear in their original form. The primary energy resources are easy to find it can be either renewable or non-renewable.
- non-renewable energy such as coal, natural gas, and nuclear power are the types of primary energy.
- renewable energy such as solar, hydro, and wind are some of the types of primary energy.
Secondary sources of energy come from primary energy sources and can be used more than once. For instance, burning the wood makes it a secondary source, because you get energy from the tree.
Fossil fuels like coal, natural gas, and nuclear power are the primary energy sources. These sources, on combustion, produce thermal energy, which is secondary energy. It is then used to generate steam, which operates a generator to produce electricity.
The types of secondary energy sources include
- solar power generated from the sun,
- wind power from wind turbines,
- geothermal energy deep under Earth’s surface,
- hydropower is generated from water running downhill through dams to spin generators.
Commercial and Non-commercial energy
Commercial sources of energy can be bought at a store or online for money. These commercial energies are non-renewable because they cannot be replaced once used up. Commercial types of energy include diesel, lignite, coal, crude oil, and electricity. These energies are imported and exported to and from different countries for money.
Non-commercial sources of energy are usually free or very cheap. It cannot be traded in the commercial market. Non-commercial types of energy include renewable resources like sunlight, wind, rain, and geothermal energy under Earth’s surface.
Agricultural wastes, cow dung, rice husk, firewood, cattle dung, sugarcane waste, and coconut shells come under the non-commercial types of energy.
Renewable and Non-renewable energy
Non-renewable energy sources are finite and can’t be replenished, and cause serious damage to the environment. Non-renewable sources include coal, natural gas, nuclear power, and oil.
These fuels have been formed over a long period of time from the remains of plants and animals whose CO2 was converted over millions of years into fossil fuels.
In contrast, renewable energy sources are those which can be sustained infinitely as they can be replenished quickly. Renewable energy is constantly produced in nature so it will not run out over time.
The most common types of these include hydroelectric power, wind power, tidal energy, biomass, and solar energy. Such renewable energy does not make any harm to humans and the environment.
What are the different types of energy?
Although there are different types of energy, all are broadly classified into two types: kinetic energy and potential energy.
Potential Energy is the stored form of energy that results from an object being at rest. It is one of the different forms of energy that is stored in an object due to its position “up high” or “down low.”
In physics, the term “potential” indicates a property that has not been actualized yet but could become so with time and effort. Potential Energy also refers to the unused ability to do work. For instance, A man standing in a rest position possesses some potential energy.
Following are a few real-time examples of potential energy.
- A man standing at rest
- a book placed on a table
- water stored in a dam
- a car parked at the hilltop possesses potential energy
- a ball held above the ground
- gasoline stored under pressure in a car’s gas tank
- a stretched rubber band
Fossil fuels are another type of potential energy that can be used to create kinetic and thermal energies for many purposes. A ball resting on a hilltop has potential energy. It is transformed into other forms of energy if it rolls down the hill and becomes moving.
A bomb has more potential energy in chemical form. When exploded, the stored energy is converted into heat energy.
It is the energy of an object that is in motion relative to other objects. When you apply a force on any object, it gains kinetic and moves. It is simply the energy in motion.
Let us look at a familiar example of a football game. When someone kicks a ball, he puts a lot of effort into his kick. The ball gains a lot of kinetic energy and will bounce off your foot quickly and go further than it would have if you simply dropped it to the floor.
Similarly, a car parked at the top of a steep hill has potential energy because it is not moving forward or backward. If the parking brake is released, it will gain kinetic energy as it moves forward or backward. In simple words, it is the energy of moving objects.
In the above figure, there are four balls at rest. Hence they possess potential energy. When the fifth ball having some kinetic energy hits the other balls, the energy in the fifth ball is transferred to the other four balls. Thus four balls at rest gain kinetic energy and start to oscillate.
Other types of Energy
There are various forms of energy available throughout the universe. Without the existing forms, it is impossible for lives to sustain on the earth.
Let us discuss the different energies such as thermal energy, mechanical energy, light energy, electrical energy, sound energy, nuclear energy, gravitational energy, etc.
Thermal energy also called heat energy is produced as a result of a rise in temperature in a substance. When the temperature in a substance increases, it gains more energy.
When the temperature of a substance increases, the atoms inside it will move faster and creates more thermal energy. Also raising or lowering the temperature can also change the shape of the object.
The transfer of thermal energy happens in four forms: conduction, convection, radiation, or reflection. Conduction is the process of heat transmission through a substance like metal. Convection is the process by which heat moves through a fluid like air or water.
Radiation is the process in which heat emitted travels away into space. And finally, reflection occurs when heat bounces off a surface and travels in another direction.
There are a lot of examples of thermal energy usage in our daily life. Some of them are making
- a cup of hot tea,
- baking a cake in the oven,
- Heat emitting from the heater
- melting and forging metals
- the warmth of being under the sunlight
When you stand under the sun, its heat energy is absorbed by your body. Similarly, when making a cup of tea, thermal energy from the fire is transferred into the milk to make it boil.
Chemical energy is the energy associated with atoms and molecules of a chemical substance. The more chemicals are mixed together, the higher their combined energy becomes. Energy can be released when substances interact with one another and change chemically.
Chemical energy can be found in foods that you eat every day that comes from different sources such as carbohydrates, lipids, and proteins through the process of metabolism. Almost all living organisms rely on such chemical reactions inside them.
Let us look at some examples. In the combustion process of burning wood, a chemical reaction takes place with heat and oxygen. As a result of this combustion process, it releases carbon dioxide, water vapor, and ash.
Similarly, in the process of baking bread, the yeast reacts with sugars and transforms them into carbon dioxide and alcohol.
Due to the chemical energy present inside the volcano, hot molten rock and ash escape through the earth’s crack.
Chemical energy can be found in
- Photosynthesis in plants
Mechanical energy is the combination of energy stored in an object by virtue of its motion and its position. When work is done to an object, it moves or changes its position due to forces acting upon them. Hence it is also called Motion energy.
Objects with a certain amount of potential energy have the capability to release the energy stored as kinetic or movement energy.
A simple example of mechanical energy is a ball at the top of a hill – its gravitational potential force will create a kinetic force as it rolls down. More the stored potential, the greater amount of work it can do on any given level surface.
Consider another example of using a hammer to hit a nail and drive it into the wall. When the hammer is at rest, it possesses potential energy. When you swing the hammer and hit the nail, the kinetic energy act on the nail and makes it penetrate into the wall.
So the mechanical energy which is a combination of both energies will cause the nail to drive through the wall. Some other examples are
- rotating wind turbine
- riding a bicycle
- hitting the ball
- Sharpening a pencil
- Driving a car
It is the energy that is used to power appliances in your home such as television, refrigerators, air conditioners, and so on. Electrical energy is caused by the flow of electrons.
Electrons are negatively charged particles that flow through certain materials when there is an electrical voltage or “potential difference” between two ends of the material. The resulting electric field can be used to do work on other objects.
Generally, Electrical energy is generated from fossil fuels such as coal, oil, and natural gas. There are various power plants such as thermal power plants, nuclear power plants, hydropower plants, etc., where electrical energy can be generated.
It can also be produced from other renewable energies such as wind energy, hydro energy, and solar energy. For example, chemical energy in the fuel cell, the hydropower in the water is used to run the turbine of an alternator, which generates electrical energy.
Radiant energy also called light energy, is one of the different forms of energy in the form of light or electromagnetic waves. The word light includes all forms of electromagnetic radiation: X-rays, ultraviolet, visible light, infrared radiation, and even cosmic rays.
Hence it is also called electromagnetic energy. The radiant energy is made up of tiny particles called photons.
The radiant energy can be observed in the explosion of fireworks. When it explodes, they emit visible light. The sun is also an example of light energy because its rays are radiated toward the earth and can be visible as light during the daytime.
A few other examples are
- LED lights
Nuclear energy is a type of energy stored in the nucleus of an atom. There are two types of nuclear reactions: fission and fusion. Energy is released as a result of a fission reaction, where atoms split apart. Similarly, more energy is released during a fusion reaction, where atoms merge together.
The process involves splitting or combining isotopes in order to produce nuclear fuel. This can be done by bombarding uranium with neutrons until it splits into smaller particles, releasing heat and radiation as a result. It is then converted into electrical energy.
This process is performed in nuclear power plants to produce electricity. Nuclear energy can be utilized to provide power for homes and factories, but there are concerns surrounding the safety of this form of energy production and storage.
It is the energy associated with an object due to its position in a gravitational field. The sun and all celestial bodies create gravitational fields. The earth has a constant gravitational pull, and because of that, you are standing on earth.
In simple words, it is because of gravity. Gravity is the force that pulls objects toward the center. It is a universal attractive force and has an infinite range (it never diminishes). Gravity’s strength is based on the planet’s mass.
As said, the Sun is the main source of gravitational energy. The Earth’s gravity pulls you down, and it also pulls the Moon to rotate around the Earth’s orbit. You have to use your energy upwards to lift heavy things because they are being pulled toward the ground by gravity.
Similarly, when you throw a ball, it always comes to the ground. Also, when you jump high, you always land on the ground but not on the moon or mars. Why does it happen?
It’s all because of the gravitational energy acting on the earth.
Some other examples are
- water stored in the dam
- Water falling from a waterfall
- ripe fruit when falling from a tree
- throwing a ball upwards
Sound energy travels through the vacuum in the form of waves. It is created by vibrating objects and can be transferred from one object to another as it travels through a medium such as air.
The speed at which sound travels depends on the type of material, as well as its temperature and density. In general, for each doubling of distance traveled, the speed of sound drops by about 6 decibels.
When you speak or when you shout loudly, sound energy can be produced. Sound can be created by mechanical vibrations – for example, hitting two cymbals together creates loud clashing sounds because they vibrate back and forth at high speeds.
It can also be created by objects moving in fluids like water or air – whales use their flippers to create high-pitched noises called whale songs while dolphins produce low-frequency clicks with their teeth.
Elastic energy is the ability of an object to be stretched or compressed and then return to its original shape. It is the energy stored in solid, elastic objects when they are stretched or deformed.
Energy is stored in many physical systems, including stretching rubber bands, bending metal bars, and even water pressure. Elastic energy can be converted to other forms of energy.
The amount of elasticity in a material can be determined by measuring its extension at break or stress. A rubber band has more elastic energy than a steel wire because it will stretch farther before breaking.
Imagine the elastic energy in the coiled spring, which can be stretched and compressed too. The amount of elastic energy in spring depends on the type of material in the spring.