The energy efficiency index (EEI) is an important factor used as an indicator either for building energy consumption or electronic device performance; it allows one to select effective devices that save energy. This work studies the performance of different types of LED lamps used in indoor lighting, the lamps currently available in the Egyptian market have been tested according to their photometric and electric parameters, namely: luminous flux, power factor, and EEI. Three different brands E, T, and V have been chosen with the nominal powers 9, 12, and 15 W. The results showed that both 9- and 15-Watt lamps have the same EEI values as 0.14, 0.13, and 0.12 for T, V, and E lamps, respectively, whereas 12-Watt lamps have EEI values of 0.16, 0.13, and 0.13 for T, V, and E lamps, respectively. The experimental testing of these lamps revealed that all the lamps have the same EEI class (A+) regardless of the nominal power. The results also revealed a relationship between the power factor and EEI: as the power factor increases, EEI increases, too. The expanded uncertainty in luminous flux has been calculated.

Electrical power efficiency has been of interest to both energy providers and consumers as it plays a pivotal role in our daily life. The voltage fluctuation is a significant issue with power quality since it has a substantial influence on electronic devices in addition to its economic impact. Several contributions have been dedicated to estimating the uncertainty in luminous flux including various parameters; however, most of them have been focused on traditional light sources such as incandescent lamps. One of the main parameters that have not been considered is the uncertainty in electric power due to voltage instabilities. In this study, the effect of regulating the electric power on the luminous flux and its combined uncertainty for different brands of LED lamps were explored. The LED lamps currently available in the Egyptian market have been tested according to their photometric and electric parameters. Three different brands labeled E, T, and V have been chosen with nominal power of 9 and 15 Watt. The experimental testing of such lamps showed that the power factors have a considerable effect on the combined uncertainty of the overall luminous flux.