Case study of a highly-reliable dimmable road lighting system with intelligent remote control

This paper presents the phase-one results of a case study of a dimmable road lighting system with intelligent remote control. This is the first large-scale installation of such system for about 8000 street lamps in China and the phase-one of the project involves 1350 lamps. Patent-pending central control dimming systems, that can turn existing "non-dimmable" electromagnetic lighting systems into dimmable ones without major rewiring or replacement of equipment, have been installed in Heshan City, China since September 2004. This central dimming system provides a self-recovery feature and ensures high lighting system availability, as it will automatically withdraw itself from the lighting network if it cannot work normally. By retaining existing electromagnetic ballasts in all lamp posts, the use of this central dimming system does not require any expensive electronic ballasts. More importantly, electronic ballasts may help save some energy for a few years of their short lifetime but will become electronic waste and pollutants for many hundreds of years. The proposed system in this paper provides an environmentally-friendly and energy-saving solution for dimmable road lighting systems. Most of the advantages of electromagnetic ballasts such as long lifetime, recyclability of iron chokes, high reliability and immunity against extreme weather conditions and lightning are kept. During the 9-month operation, none of the streets with such dimming system installed suffers light blackout. It has also been independently confirmed that there was no increase in crime and traffic accident rates. No compliant has been received from residents by the road lighting management company. In phase-one of this project, an overall energy saving of 27% has been recorded without adversely affecting quality of life.