What is an energy?

Energy can be defined as the capacity to perform work, and it is able to be converted or transferred from one form to another. This transformation can take place in either direction. It is the capacity to perform work or bring about transformation. There are many distinct kinds of energy, such as kinetic energy, which is the energy of motion; potential energy, which is the energy of position or configuration; thermal energy, which is the energy of heat or temperature; chemical energy, which is the energy that is stored in the bonds of atoms and molecules; and electromagnetic energy, which is the energy that is transferred through electromagnetic waves (the energy of light and other electromagnetic radiation).

Energy is a fundamental notion in a wide variety of disciplines, such as physics, chemistry, and engineering, and it plays a significant role in gaining a knowledge of how the cosmos functions. Both the shape that energy takes and the way it is used can be altered through the process of energy conversion. For instance, the potential energy that is stored in the chemical bonds of gasoline can be turned into kinetic energy by burning the gasoline in an engine. This kinetic energy can then be used to power a car or another type of vehicle.

When discussing energy, it is common practice to refer to it in terms of units of effort, such as joules or calories. The amount of energy that is required to carry out a particular activity or piece of labor is contingent on the specifics of the activity as well as the efficacy of the process that converts energy into work that may be put to good use.

What is an energy source?

An energy source is a source of energy or a means of obtaining or producing energy. Energy sources can be broadly divided into two types: renewable and non-renewable. Renewable energy sources, such as solar, wind, and hydroelectric power, may be renewed or regenerated in a relatively short amount of time. Non-renewable energy sources, such as fossil fuels, are limited in quantity and cannot be regenerated or restored once exhausted (e.g., coal, oil, and natural gas)

There are two categories that can be applied to the various energy sources.

  • Renewable energy sources
  • Non-renewable energy sources

Some common examples of renewable energy sources

Some common examples for the renewable energy sources can be listed as follows:

Solar energy: energy from the sun, which can be captured using solar panels or other solar energy technologies.

Wind energy: energy from the wind, which can be captured using wind turbines.

Hydroelectric energy: energy from the movement of water, which can be captured using dams or other hydroelectric facilities.

Geothermal energy: energy from the Earth’s internal heat, which can be captured using geothermal power plants.

Biomass energy: energy from organic matter, such as wood, agricultural waste, or landfill gas.

Some common examples of non-renewable energy sources

Some common examples of non-renewable energy sources include:

Coal: a fossil fuel formed from the remains of plants that were buried and subjected to high pressures and temperatures over millions of years.

Oil: a fossil fuel formed from the remains of small aquatic organisms that were buried and subjected to high pressures and temperatures over millions of years.

Natural gas: a fossil fuel formed from the remains of plants and animals that were buried and subjected to high pressures and temperatures over millions of years.

Uranium: a radioactive element that can be used as a fuel in nuclear power plants.

Renewable energy sources

Renewable energy sources are those that can either be recreated while they are being used or within a relatively short amount of time after they have been used.

  • Energy of the flowing water
  • Solar power
  • Bio-mass
  • Wind power
  • Geothermal energy

Non-renewable energy sources

After they have been used up, non-renewable sources cannot be replaced. If not, the process of reproduction will take a large amount of time.

  • Fossil fuel
  • Nuclear power
  • Coal
  • Natural gases

Energy sources and It’s energy

Solar power

Solar energy provides both light and heat. Solar power is also responsible for wind in the atmosphere and waves in the sea. Roof-mounted solar heaters can be observed in certain homes. These heaters are used to heat water for bathing reasons.

Sun cells convert solar energy into electricity. Solar cells were initially developed to power artificial satellites. They are currently utilized in calculators, electric cars, street lamps, and aero planes.

Process in solar cooker

A solar cooker is a device that cooks food using sunlight. There are numerous varieties of solar cookers, but they all function by heating a cooking chamber, which then cooks the food. Here’s a description of the procedure:

The solar cooker is put in a bright spot where it will receive direct sunlight.

A reflector or series of reflectors (such as mirrors or aluminum foil) are used in the cooker to focus the sun’s rays onto a cooking chamber.

When sunlight is directed towards the cooking chamber, it is absorbed by the walls, which then heat up.

The heat from the cooking chamber’s walls is transferred to the food being cooked by conduction (direct contact with the chamber’s walls) or convection (circulating hot air inside the chamber).

The heat of the cooking chamber cooks the meal. The cooking time will be determined by the amount of sunshine, the size and design of the cooker, and the sort of food being prepared.

Solar cookers are an easy, sustainable, and eco-friendly way to cook meals. They do not require any fuel and emit no greenhouse gas emissions. They are especially beneficial in locations where fuel is limited or expensive, or where it is necessary to lessen reliance on fossil fuels.

Disadvantages of using solar power

Even though solar electricity is sustainable and economical, it has significant drawbacks.

Solar batteries are prohibitively expensive.

The efficacy of solar batteries is reduced when the sky is cloudy.

Solar-generated electricity can be stored in batteries. However, batteries can only hold a limited quantity of electricity and must be disposed of properly after discharging. Improper disposal will pollute the environment.

Wind power

Solar energy heats the earth unevenly in different parts. When air is heated, it rises, creating a low pressure zone in the atmosphere. Cool air from other regions enters the gap. The wind is the circulation of chilly air. Wind was used for a variety of reasons by ancient man.

  • Paddy’s cleaning
  • Windmills are used to grind grain.
  • Sailing boat transportation
  • Wind can be used to create electricity.

Wind energy has advantages as well as problems. The benefits are that it does not pollute the air, can be gotten for free, and causes less environmental impact.

However, wind sufficient to create power can only be found in a few places. Wind-powered electricity generators produce noise pollution.

Wind occurring

Geothermal energy

Geothermal energy is thermal energy that is created and stored in the earth. Magma is a hot, molten rock found beneath the Earth’s crust. The high temperature in this layer causes the water to heat up and turn into steam. This steam is then pumped out to power a turbine. This turbine creates electricity by driving a dynamo.

More research into generating electricity from thermal springs should be conducted. Geothermal energy appears to be very economical because it uses energy from deep within the earth’s crust.

However, there are numerous disadvantages to using geothermal energy. Extremely hot spots on Earth are located deep within the Earth’s crust. As a result, in order to utilize geothermal energy, the earth must be excavated quite deep. It requires a lot of energy and has a significant cost. Furthermore, numerous hazardous gases and chemicals can seep up from beneath the ground, and finding a way to safely dispose of them is difficult and risky.

The energy of flowing water

Since ancient times, people have harnessed the power of moving water to drive turbines that generate electricity. Grain was ground with those wheels at one point. Utilizing the kinetic energy that is created by water in motion can result in the production of electricity. A hydropower station is a facility that generates electricity by utilizing water as one of the primary resources.

Process in hydropower stations

The energy of falling water is used to turn a turbine attached to a generator at hydropower facilities, which generate electricity. Here’s a high-level overview of the procedure:

  • A dam or reservoir is built across a river or stream to collect water.
  • The water is released from the dam or reservoir and flows towards the hydropower station via a canal or pipe known as a penstock.
  • Because of the pull of gravity, water gains kinetic energy as it runs through the penstock.
  • The water is directed onto the turbine blades, causing the turbine to spin. The turbine is linked to a generator, which turns the spinning turbine’s mechanical energy into electrical energy.
  • The electricity is subsequently distributed to homes, companies, and other customers via the power system.


Biomass energy is the energy which is contained inside the animals and plant materials. Firewood is also considered as biomass. The amount of heat generates depends on the type of firewood.

In India, dried cow dung is used as a fuel for the preparation of food in households. Indian government encourages people to use cow dung to make biogas and use it as a fuel. Fuels produced using plant materials are considered as renewable energy sources. As long as we continue to plant new trees to replace those cut down we will always be able to get those fuels.

Non-renewable energy sources

Mineral oil

Mineral oil is a type of fossil fuel. Fossils are formed from plant and animal matter that has been subjected to various subterranean reactions. The fuels derived from these fossils are known as fossil fuels. Mineral oil is trapped in the earth’s crust among the rocks. To transport the mineral oil, metal tubes need be dug inside the rocks. Mineral oil is a widely utilized fuel in manufacturing and transportation.

Mineral oil has the advantage of being simple to use (handle) and easily convertable to energy by contemporary equipment.

The downsides are a limited supply and the emission of gas pollutants when combusted.


Coal, like mineral oil, is a fossil fuel. Coal mines can be discovered in the earth’s core rock layers. Coal combustion produces a large amount of heat that is easily handled.

Coal mines are easy to get from the ground and easy to burn. In the world, there are more coal (mines) than mineral oil (mines). The gases emitted by coal combustion pollute the environment.

Natural gases

Natural gases are methane gases trapped within the earth’s crustal rocks. Natural gases are a sort of fossil fuel as well. Metal tubes are drilled through the rocks to extract the gases. Natural gases are used to cook meals and to heat homes in colder climates.

Natural gas has numerous advantages, including low cost and ease of usage. Pollution is lower than that of coal and mineral oil. However, the supply is restricted.

Nuclear Power

Nuclear reactions in the sun provide energy. During these processes, one sort of atom transforms into another. Uranium, a radioactive atom, is used to generate nuclear energy. Nuclear power is used to create electricity in nuclear power plants.

A small amount of radioactive atoms, such as uranium or, is required to generate a large amount of energy. This is a benefit of nuclear energy.

There are various drawbacks to using nuclear energy. The cost of installing and sustaining nuclear power plants is high. As a result, highly hazardous compounds are emitted. As a result, they must be preserved for thousands of years without being exposed to the environment. This is another extremely costly task.

If radioactive substances are accidentally released, it creates hazardous conditions. It will be destructive to both people and the environment.

The waste from these reactors is extremely poisonous. They should be stored in such a way that they are not exposed to the environment for an extended period of time. These discharges are expensive to store. If these radioactive compounds are accidentally released into the environment, they will harm both people and the ecosystem, leading to a terrible conclusion.

Sustainable usage of energy sources

It is our duty to use nonrenewable energy sources wisely, as they will vanish one day. As a result, future generations will be unable to use these energy sources.

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About Author

Anuradhika Lakmali

Anuradhika Lakmali is a co-founder of Science A Plus learning network. She is working as a government teacher and has interest in chemistry, biology, phisics and self development.