What is Efficacy
In the lighting industry, efficacy refers to the measurement of how efficiently a light source converts electrical power into visible light. It is expressed as the amount of usable light produced by a light source per unit of electrical power consumed, typically measured in lumens per watt (lm/W). Efficacy is a factor to consider when selecting lighting fixtures as it indicates the efficiency of the fixture in converting electrical energy into visible light.
Efficacy is different from efficiency, which measures the percentage of light emitted from a fixture and light source when energized. While efficiency focuses on the amount of light emitted relative to the total light produced, efficacy specifically quantifies the amount of usable light produced per unit of electrical power consumed.
When evaluating the efficacy of a lighting fixture, a higher value indicates a more efficient conversion of electrical energy into visible light. This means that the light source can produce more light while consuming less energy. It is important to note that efficacy can vary depending on the type of light source and technology used.