light energy numeric indicator (LENI)

Light Energy Numeric Indicator (LENI) is a reference value for lighting efficiency. This value is calculated from the quotient of the energy consumption for lighting to the square meters in relation to the year.

The calculation procedure is described in the European standardEN 15193 for the "Energy Rating of Buildings". The LENI value increases with the energy efficiency of the lighting, its time-of-day control and the control by occupancy sensors. On the other hand, excessively long lighting times, high charging energies for emergency lighting and lighting times during daylight have a negative effect.