The reflections on energy costs and efficacy problems of modern LED lamps

Currently the technology of electroluminescent light sources has undoubtedly dominated the lighting market and LED lamps are replacing the traditional light sources which are being withdrawn from the market. Powering light-emitting diodes requires the use of the appropriately selected power supply systems. All power supply solutions use electronics, mainly voltage converters, which can generate much capacitive reactive power that may cause a contractual penalty in settling electricity costs. Therefore, using LED lamps may lead to an unnecessary increase in electricity bills. This paper presents the basic information about modern types of LED lamps with the Edison E27 base. The definition and basic requirements for the power factor for LED lamps and problems related to it are also discussed. The basic electrical and photometric parameters were measured for the selected 77 samples of LED lamps available on the market in 2023. The conducted research has shown that the average luminous efficacy of LED lamps with the power ranging from 4 W to 20 W is 105 lm/W. However, the power factor most often ranges from 0.5 to 0.6 (68 % of cases). The novelty of this paper is related to presenting the complete operation costs of LED lamps considering reactive energy. In the case of the conducted research, on average, a five-fold increase in the costs of using the LED lamp in an annual cycle was proved. It is mainly related to the low power factor issue and the requirements of this parameter needing to be more restrictive. Therefore, the need to introduce alternative, more stringent requirements related to the power factor of LED lamps was proven and proposed. The new approach to the definition of the luminous efficacy of an LED lamp by referring to its power factor or apparent power as well as tips helpful to users choosing an LED lamp, can also be found in this paper. • The average value of the (photopic) luminous efficacy of an LED lamp is 105 lm/W. • The average value of the power factor of an LED lamp is 0.62. • The average increase of LED lamps operating costs per total energy is fivefold. • Power factor requirements of LED lamps must be more stringent. • It must be considered to relate the luminous flux with total power for LED lamp.