Intrinsic energy consumption efficiency is one of the indexes indicating the degree of energy efficiency of lighting fixtures, and represents the brightness provided by 1W of electric power.
The index is obtained by dividing the amount of light (luminous flux: lm) emitted from lighting fixtures by rated power consumption (W), expressed in units of lm/W. The larger the value, the more likely electric energy is converted to light, indicating higher energy efficiency.
Furthermore, the calculation method for the intrinsic energy consumption efficiency of LED lighting fixtures is defined in the "Guidelines for Representation of LED Lighting Fixtures Performance" (guide 134:2010), and the calculation method for the energy consumption efficiency of fluorescent lamps is defined in the Energy Saving Act (Act on the Rational Use of Energy). According to these definitions, the intrinsic energy consumption efficiency of LED lighting fixtures is the value obtained by dividing the luminous flux of lighting fixtures by electric power, while the energy consumption efficiency of fluorescent lamps is the value obtained by dividing the luminous flux of a single unit of fluorescent lamps by electric power. As such, the definition of "luminous flux" differs between the two, and energy efficiency of LED lighting fixtures and fluorescent lighting fixtures cannot be compared simply by using this value.