What is radiant energy?

Radiant energy is an essential form of energy on our planet that often goes unnoticed because only a small fraction is visible to the human eye.

It is a source of energy that comes mainly from the sun, propagates in the form of electromagnetic waves, and sometimes requires specialised equipment to detect it.

In addition, we can consider radiant energy to be vital, as we use it in many areas such as long-distance communications, agriculture or to heat our homes.

Radiant energy sources

The largest natural source of radiant energy is the sun, which emits electromagnetic waves that reach our planet and are essential for processes such as photosynthesis. In addition to sunlight, stars also emit radiant energy, although, of course, we do not benefit from it to the same extent due to their distance and lower intensity compared to the sun.

If we focus on the artificial realm, we find multiple uses of radiant energy. Light bulbs, for example, provide illumination by emitting light, microwave ovens use high-frequency waves to heat food, and radiodiagnostic medical equipment such as X-rays use radiation to obtain internal images of the human body.

Types of Radiant Energy

Depending on the intensity, frequency and wavelength, we can differentiate between various types of radiant energy. Here are some of the most important ones:

• Visible light: This is the only type of radiant energy that can be perceived by the human eye. It covers a spectrum of wavelengths ranging from 400 to 700 nanometres.

• Ultraviolet rays: Present in the sun’s rays, they have a wavelength between 400 and 100 nanometres, shorter than that of visible light but longer than that of X-rays.

• Infrared rays: A type of electromagnetic radiation produced by the heat contained in any body, from a flame to a light bulb to the sun’s rays.

• X-rays: Widely used in medicine, they are able to pass through opaque bodies and create a photographic impression, better known as an X-ray.

• Gamma rays: Produced mainly by radioactive elements or as a result of subatomic processes.

Solar Energy

Solar energy is a form of radiant energy that has become a key player in the transition to more sustainable energy sources. Using technologies such as photovoltaic panels and solar thermal collectors, the sun’s energy can be captured and transformed into electricity and heat.

When talking about solar energy, we can differentiate between two main types: solar photovoltaic and solar thermal.

Photovoltaic solar energy uses solar panels that convert sunlight directly into electricity through the photovoltaic effect. This technology is ideal for self-consumption and can be installed in homes as well as in large solar plants.

Solar thermal, on the other hand, uses solar collectors to absorb heat from the sun and transfer it to a fluid, which is then used to generate steam and produce electricity to heat water and different spaces. This technology is typically used for both industrial and residential applications.