What is the unit of measurement for Radiant power?

The unit of measurement for radiant power is watts. Radiant power, or radiant flux, reflects the amount of energy emitted by a source in the form of electromagnetic radiation per unit time. Watts are used to quantify the rate at which energy is transferred or converted, making them the appropriate unit for measuring radiant power.

In this context, joules represent energy rather than the rate at which it is emitted. Kelvins measure temperature, particularly in the context of color temperature of light sources, and are not directly related to the measurement of radiant power. Lumens measure luminous flux, which is the perceived power of light by the human eye and is relevant in visual perception but does not correspond to the total power emitted by a light source. Thus, watts are the correct unit for radiant power.