Naturally occurring sources of radiant energy such as the sun can be converted into usable electricity with solar power or used as passive solar.

Radiant energy travels in wave forms. Types of radiation with higher frequency are higher energy. As the source material is excited, the radiation of energy is increased. One can see this in effect with the turning up of a dimmer switch: As the power is increased, more light is emitted from the bulb, be it LED or incandescent. This effect is the result of more photons are radiating off in all directions.

In applications involving transmission of power from one location to another, “radiant energy” is sometimes used to refer to the electromagnetic waves themselves, rather than their energy (a property of the waves).

Because electromagnetic (EM) radiation can be considered to be a stream of photons, radiant energy can be viewed as the energy carried by these photons.

Alternatively, EM radiation can be viewed as an electromagnetic wave, which carries energy in its oscillating electric and magnetic fields.