Life Cycle Assessment of Lighting Systems and Light Loss Factor: A Case Study for Indoor Workplaces in France

Abstract

Life cycle assessment (LCA) methodology has been used to evaluate the performance of the following lighting systems: compact fluorescent lamps (CFL), light-emitting diode (LED) lamps, and fluorescent tubes (T5 type). This work covers the singularity of the French electricity mix for indoor workplaces lighting and describes the best strategy for lamp replacement. We have defined the light loss factor to integrate the following additional parameters: lumen depreciation, dirt accumulation, and risks of failure. Therefore, we propose a new definition of the functional unit (maintained megalumen hour), and we conduct this assessment to be compliant with the standards of lighting system equipment (NF EN 12464-1). Unlike previous studies, we observed that the manufacturing phase is the most impacting over the whole life cycle, thus making the extension of LED lamps’ lifetime a more effective strategy to reduce the potential environmental impacts than increasing their efficacy. This paper highlights how the light loss factor affects the LCA results and proves that it should be taken into account for subsequent assessments. Finally, this new approach includes the real usage of the lamps in the study and contributes to lay the foundation for life cycle sustainability assessment to also evaluate the economic, social, and human impacts of lighting.