What Is Radiant Energy And What Does It Mean For Solar?

Radiant energy, also known as electromagnetic radiation (EMR), is energy transmitted without a mass movement. Radiant energy is the energy of electromagnetic waves. Two examples of radiant energy are the warmth from a hot stove and the heat from direct sunshine.

solar radiant energy

Light energy is a type of radiant energy found in an electromagnetic wave—a little “packet” of energy is carried by tiny particles, known as photons. Since photons are so tiny, the energy of light is commonly identified in electron volts. People can only see photons with an extremely narrow range of energy, known as visible light.

The range of all electromagnetic (EM) radiation or radiant energy types is known as the electromagnetic spectrum. Microwaves, infrared light, ultraviolet light, X-rays, and gamma rays are the other radiant energy types that make up the electromagnetic spectrum. Less than 1% of this radiation is emitted in the radio, UV, and X-ray spectral bands. The sun radiates energy evenly.

The usage of radiant energy collection includes

The usage of radiant energy collection includes:

  • Solar energy converts the radiant energy in the sun’s light into electricity.
  • Photosynthesis is the process through which plants capture and utilise light energy. They take in solar radiation and convert it into chemical energy stored in molecules within their cells. Animals can consume plants or animals that have recently consumed other animals or plants to receive some of this chemical energy as food. Plant biomass can also be utilised to make biofuels.
  • Radiant energy from a radioactive source is used by radioisotope thermal generators to generate heat or electricity.

Discussing radiant energy collection typically refers to the power of sunlight passing through a square metre when facing the sun directly, and the earth is at its distance from the sun. The solar constant, roughly 1370 watts per square metre (W/m2), measures the sun’s strength per square metre on earth. The solar constant varies by +/-3% because of the Earth’s slightly elliptical orbit around the Sun.

There are several ways to apply radiant energy:

  • Tanning in the sun.
  • The burner on a stove.
  • Spending time by a campfire.
  • Radiant energy (light) is required for human vision to see.

Any radiant energy from the sun is referred to as solar radiation. It is also known as a solar resource. Technology transforms solar radiation into several types of energy, including heat and electricity. 

The amount of sunlight at a specific location at a particular time is a key point when designing solar PV systems. Solar radiance and solar insolation are the two commonly used measurements to describe solar radiation. The solar radiance is the kilowatts per square metre instantaneous power density. While the amount of solar radiation, or electromagnetic energy, that is received at a specific location on the earth’s surface is known as solar insolation.

The sun rises in Australia at an angle towards the north facing aspect. So your home generates more radiant heat from windows that face north. Because Australia is located in the southern hemisphere, it receives sunlight primarily directed northward.

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Energy Matter's quick survey


  • The entire distribution of electromagnetic radiation defined by frequency or wavelength is known as the electromagnetic spectrum.
  • Light energy is radiant energy that the human eye can see.
  • Radiation is the emission of energy as electromagnetic waves.
  • Radiant energy is the energy of electromagnetic waves, also known as electromagnetic radiation.
  • The solar constant measures the mean solar electromagnetic radiation per unit area using flux density. Solar Constant = 1.4kW/m2.
  • Electricity produced with the help of solar radiation from the sun is known as solar energy.
  • The flow of solar radiation per unit of horizontal area for a specific location is known as solar insolation.
  • The solar radiance is the kilowatts per square metre instantaneous power density.
  • Solar radiation is any electromagnetic radiation that comes from the sun.


Solar Power vs Solar Energy

Power and Energy are two different functions. Most people interchange these two important terms in the industry. 

Electrons in a wire generate electrical current, and the speed at which they move indicates the power of electricity. So Power refers to the speed of electricity. Basic units are joules per second and measured in kilowatt (kW). A solar system’s peak kilowatt output determines its size.

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