light energy

Understanding light energy

Light energy is the only visible form of energy that serves a useful purpose to humans. It is a form of kinetic energy with the ability to make types of light visible to human eyes. The common form of light energy is the sun, which is the closest star to the planet earth. Light is made up of particles called photons and the speed of light in a vacuum is 299,792 kilometers per second, which is quite fast.

Today you’ll get to know the definition, uses, properties, types, units, diagrams, and examples of light energy.

light energy

Read more: Various types of energy and their examples


What is light energy?

Before we look into the definition of light energy, let me explain the term lightly. Light is a form of energy that plays a very vital role in human’s lives because that is what we use to see everything. If we can’t see we can do anything.

Light energy can be defined as the energy produced by vibrations of electrically charged particles. It is a form of electromagnetic radiation emitted by hot objects like lasers, bulbs, and the sun. light contains photons which are the source of energy. when an object’s atoms get heated up, photons are created. This is to say, photons can be produced when an object’s atoms are heated. Light energy is released in the form of a photon and more photons are released as the substance gets hotter.

Light travels in form of waves, but no matter is necessary to carry energy along to travel. This is why light can travel through space where there is no air. Light energy is very quick and travels faster than any other source of energy, unlike sound waves that have to travel through solids, liquids, or gas. The sun emits a large amount of electromagnetic radiation. This visible light is what we humans can see.

Read more: Uses of energy in our daily life

diagram of light energy

Uses of light energy

Below are the common uses of light energy.

  • Human growth
  • Food formation
  • Sight and vision
  • Regulation of physiology
  • Heat and temperature
  • Drying and evaporation
  • Electrical energy
  • Earth sanitation
  • Germ’s elimination
  • Signaling system
  • Sterilization

Read more: Understanding chemical energy

The common uses of light energy are:

Food – light is the only source of food generation for all living organisms.

Vision – the eyes can be useless without light.

Color – the light consists of many spectra and every spectrum has an individual color which is broadly specified as VIBGYOR.

Properties of light

Below are the properties that can be obtained from light energy.


the intensity of light is the rate at which the light energy is emitted by the source. It can also be defined as the brightness measured at the rate at which light is emitted in a unit surface or energy per unit time per unit area. The power is expressed in units of watts.


The frequency of light is defined as the number of crests that pass through a particular point in a second.


Wavelength is defined as the distance between the two consecutive crests or troughs. Light waves pass through a vacuum at the same speed. Wavelength and frequency of light are related vice versa because the higher the frequency the shorter the wavelength.


This is a process in which unpolarized light is converted to polarized light. Light waves vibrate in more than one plane and are hence called unpolarized light.

Read more: Understanding renewable energy


Phase is a particular point in the time period during the cyclic waveform. The intensity of light increases when the waves are in a phase.

Examples of light energy

In our daily life, we must come across one or more examples of light energy.

  • A very common example is the sun which is also a start, transmits light energy to the earth
  • Hot objects, for instance, a cooking pot on a burner.
  • Lightbulbs used to lighten a room
  • A laser used mechanically for metal cutting
  • Traffic light.


Below are the units of light.

  • The wavelength of light λ is measured in both Angstrom and nanometers.
  • The frequency of light is measured in Hertz.
  • Light energy is measured in electron-volts (eV).

Read more: Understanding Non-renewable energy resources

Watch the video below to learn more about light energy:

Types of light energy

Light energy can be classified into several types.

Visible light:

Visible light is a type of electromagnetic energy that can be seen through the naked eye. The main source of visibility is the sun and it can be emitted by lanterns, flashlights, light bulbs, etc.

Infrared light:

The infrared is also a type of electromagnetic energy that emits heat. It is used to switch on your television through the remote since infrared waves can travel from the remote to the TV.

X-rays and Ultraviolet light:

X-rays and Ultraviolet light are short light waves used by doctors to take photographs inside the human body to find out what’s wrong. Dentists also use x-rays to check the depth of tooth decay.

Read more: Understanding solar energy

That is all for this article, where the definition, uses, properties, types, units, diagrams, and examples of light energy are being discussed. I hope you enjoyed the reading, if so, kindly share with other students. Thanks for reading, see you next time!


One response to “Understanding light energy”

  1. Wanede Samuel Avatar
    Wanede Samuel

    In fact I love you so much, I like your teachings

Leave a Reply

Your email address will not be published. Required fields are marked *