Road Lighting Energy Reduction: From HPS to LEDs - A Case Study of Uganda Street, Addis Ababa, Ethiopia

Modern technology advancements, coupled with aggressive research, has enabled the development and manufacture of superior LED luminaires. The 21
^st
century has seen significant transition from HPS to LEDs in road lighting as a measure to reduce the installed load and the amounts paid by municipal authorities to cover energy consumption costs. This paper investigated the energy saving possibilities of replacing HPS with LED luminaires - Uganda Street, a 1.35km road in Addis Ababa, was used as the case study. Dialux evo was used to determine the lighting performance, under HPS and LED lighting, with reference to the requirements of CEN13201-1 and EN13201-2. Vehicular traffic data was used to recommend a part-dimming schedule. Annual energy savings of 51.31 % and 79.75 % were realized by replacing the HPS with LED lamps and by further dimming the LEDs respectively. The study findings provide confidence for city authorities to transit from HPS to LED street lighting as a measure to reduce the overall lighting peak load and achieve huge reductions in their annual energy consumptions.