Measured energy savings due to photocell control of individual luminaires

Abstract

Lighting constitutes 20-60% of all electrical energy consumption in buildings. The results of a series of measurements to establish the electrical energy savings achieved by the photocell control of individual fluorescent luminaires are presented and compared with estimates of the performance of switchstart and 'standard' high-frequency fluorescent luminaires.The estimated annual power consumption of the test room was reduced from 5.2 W m^-2 to 0.6 W m^-2 in a room not specifically designed for daylight admittance. The study also showed that the selection of the required lux level in the room was crucial in determining the savings to be made. A further point was that the luminaires needed proper commissioning if they were to return their full potential savings.