The Energy and Financial Impacts of High-Intensity Discharge Lighting System Component Selection and Luminaire Maintenance in Industrial Lighting Applications

Abstract

Electric lighting is responsible for consuming approximately twenty-two percent of the electrical energy generated domestically, second only to that consumed by electric machinery. Of this quantity, approximately fifteen percent of the lighting energy usage is by those lighting products that fall within the category termed High-Intensity Discharge (HID). HID sources, which include Mercury Vapor, Metal-Halide, and High-Pressure Sodium, range in power level from 35 to 2000 watts. Luminaires equipped with these sources are used in outdoor lighting applications and also indoor applications, one category of which is the focus of this article - the illumination of industrial facilities. The term “lighting system” is used in this article to describe all of the elements required to illuminate the target area to required levels. This includes lamps, ballasts, housings, optical assemblies, support structures, and any other components involved in the operation and maintenance of the lighting system.

Efforts to reduce energy consumption most often revolve around the use of more efficient or efficacious lighting products which will be successful in providing the desired photometric results. In general, the more efficient the system in converting electrical energy to visible energy, the more expensive are the source and associated control gear. Consequently, the relationship between acquisition cost and performance is a major obstacle in an effort to convince users to install more efficient lighting equipment. This article reviews the performance characteristics of the various HID lamp families that are used domestically in industrial lighting applications. This includes selected energy consumption profiles, cost breakdowns, and life-cycle cost analyses of various HID lighting systems for the purpose of offering guidance to those who are responsible for the selection and application of lighting products. Also provided is an in-depth investigation into the impact of lighting system maintenance upon the energy consumption and overall cost of a lighting project as projected using life-cycle costing techniques.