Today, the IEA 4E SSL Annex, supported by ten national governments, announced the publication of a comprehensive review of all the current life-cycle assessment studies on Light Emitting Diode (LED) lamps and luminaires compared with conventional lighting technologies. This review found that energy in use is the dominant environmental impact of lighting systems, thus energy-efficient LED systems represent an opportunity to significantly reduce the impact of illuminating our buildings and outdoor areas.
The International Energy Agency’s (IEA) Energy Efficient End-Use Equipment (4E) Annex on SSL (SSL Annex) works to assist governments of member countries in promoting SSL as an effective means to reduce energy consumption worldwide. Starting in 2011, the SSL Annex launched an initiative to help assess the life-cycle impacts of LED systems compared to conventional lighting systems around the world. It provides answers to questions like ‘what are the environmental impacts of LED products over their whole life cycle?’ and ‘what are the strongest contributors to the environmental impacts of LED products?’
“The SSL Annex conducted this literature review in order to help policy-makers better understand the environmental issues surrounding LED products” said Dr. Peter Bennich, chairman of the SSL Annex’s Management Committee and representative of the Swedish Energy Agency, one of the Annex’s member countries. “The study found that on average, 85% of the environmental impact is linked to the use phase, while the remaining 15% is shared mainly between manufacturing and end-of-life treatment.”
The report focuses on nine life-cycle assessment (LCA) reports published between 2009 and 2013 that compare LED lamps and luminaires with conventional sources. The report uses the data presented in these reports, including research by the US Department of Energy (DOE), the UK Department of Environment, Food and Rural Affairs and other recent studies.
This figure below shows the findings of an LCA study by the US DOE that compares the primary energy consumed over the life cycle of three lighting technologies, incandescent, CFL and LED in 2012 and 2017. These technologies were compared for the same quantity of light output (i.e., 20 million lumen-hours), and incandescent technology was found to consume many times more primary energy, even when taking into account all stages of the lamps respective life-cycles.
The report found, for example, that halogen lamps, marketed as energy efficient lamps, have much greater environmental impacts compared to quality compact fluorescent lamps (CFLs) or LED products. And, as LED technology continues to improve, LED lamps will have even less environmental impact in the coming years. For professional lighting, the T5 linear fluorescent lamp luminaire was found to be the best-rated product in 2009. In studies published in 2013, the T5 lamp remains the product with the lowest environmental impacts, but thanks to the advances of LED technology, LED tubes are nearly at the same level of performance.
“The rate of technological improvement in LED reflected by the comparison of older and more recent LCA publications shows that there is a need for more research into the environmental impacts of LEDs and LED lighting and to keep track of the fast technical development” said Professor Georges Zissis, Head of Light & Matter Research at University of Toulouse in France and co-author of this report. “Collaboration between academic teams and the LED industry would greatly improve the quality of the research in this field, and help to ensure the research keeps pace with the rapid evolution of LED technology.”
The most difficult aspect of data collection to assess the environmental impacts of LED lighting product manufacturing is information concerning the production of the LED itself. Both die manufacturing and LED packaging are confidential, complex processes. Even if they were fully characterised, LED manufacturers often use parts and materials supplied by other companies, for which manufacturing processes are unknown. These aspects, compounded with difficulties encountered through the extraction of “sensitive” raw materials such as indium makes it difficult to take impacts into account.
The LCAs found in the literature compare incandescent lamps, halogen lamps, CFLs, HPS luminaires, induction luminaires, FL luminaires, CMH luminaires, LED lamps, and LED luminaires. The methods of the LCAs varied. The differences were found in the stages of life cycle they included, how the life cycle stages were divided and modelled, what functional unit was chosen, and which energy source or average energy production mix was chosen for the use stage. Despite the apparent differences (especially the functional unit), the LCAs were found to conclude somewhat similar results. Current research shows that the replacement of low-efficacy lamps with more energy-efficient options, including LED Lamps and luminaires, brings a strong overall environmental benefit.