The energy impact of luminaire depreciation on urban lighting

MOCKEY.I.O.; MANZANO E.R.

Energy for Sustainable Development

ELSEVIER

Lugar: Amsterdam; Año: 2013 vol. 17 p. 357 - 362

0973-0826

Road lighting facilities operate for over half of a year but they are permanently subjected to adverse weather conditions and environmental pollution. The major cause of the loss of light is generally the accumulation of dirt on the luminaires (lamps and lighting fixtures).The severity of the loss (depreciation) depends on the nature and density of environmental pollution and the degree of protection of the luminaires against dust and water. This depreciation is compensated, beginning from the design stage, by over-sizing facilities and, throughout its lifetime, by maintenance programs. There are several ways of estimating depreciation. This paper is a review of the different sources of information and findings of major investigations conducted in recent times. There is strong evidence which indicates that luminaire depreciation could be based on the level of sealing of the luminaires and on environment pollution categories. Luminaires with IP6X degree protection are only slightly influenced by environment pollution. New generations of LED luminaires are built to conform to IP6 and this will probably soon be the standard for road and urban lighting luminaires. Even if these luminaires have a higher rate of lamp survival, an exterior cleaning operation is still necessary and the luminaire depreciation behavior model will still be useful. It is important to select a convenient maintenance factor to compensate for depreciation and to reduce the number of installed fixtures or the amount of over sizing of lamp power, which significantly transcends the energy and environmental impact.