Predicting Energy Saving and Life-Cycle Cost Analysis for Lighting and Daylighting Schemes

Abstract

Energy-efficient lighting installations, together with dimming controls, can make a good contribution to building energy conservation. Energy-efficient lamp fittings provide high light-output values with less power consumption, and electronic circuitry is more efficient than conventional ballasts. Dimming controls can lower lamp output to save energy when illuminance from daylight and light fittings exceeds the target value. This article studies lighting energy consumption and cost analysis when such lighting schemes are used. The findings would be useful for planning green and sustainable energy schemes and applicable to other spaces with similar architectural layouts and lighting control systems.

Keywords:

• Daylight illuminance
• Dimming controls
• Life cycle cost
• Lighting
• Payback period

ACKNOWLEDGMENTS

The work described in this article was fully supported by a Competitive Earmarked Research Grant from the Research Grants Council of the Hong Kong Special Administrative Region, China (Project No.9041140 [CityU 116506]). A. H. L. Mak was supported by a City University of Hong Kong studentship.