Many observers question marketing claims being made for green or environmentally responsible products. The sometimes extravagant and careless way in which green products claims are made drives skepticism and begs questions concerning the actual environmental benefits to be achieved versus extra costs consumers may be asked to pay.
In our recent efforts for clients on cleaner, greener displays and solid state lighting, we have found that Life Cycle Assessment (LCA) methods for determining and making comparisons of energy consumption, carbon footprint and environmental impact are quickly becoming the norm. We expect that LCA methods and reporting will soon be broadly appreciated by consumers and used as the basis for purchase decisions.
The summary of a recent study released by Osram (Note: PDF) comparing the environmental impact of incandescent (denoted GLS), compact fluorescent (CFL) and light emitting diode (LED) light bulbs (lamps) exemplifies this move to the LCA approach. Osram is a manufacturer of all three bulb types and thus is in good position to perform such an analysis.
The particular lamp models chosen for the analysis were selected to have comparable lumen output and form factor, and color rendering index > 80. An important distinction between the lamp types was product lifetime that ranged from 1,000 hour (incandescent), 10,000 hour (CFL), to 25,000 hour (LED). The aim of the Osram LCA was to analyze the environmental impact of an LED lamp over its entire lifetime – from raw materials, to end of life disposal – and to compare that impact to CFL and incandescent lamps. The overall life cycle impact was analyzed as illustrated below:
The LCA was divided into five stages – raw material production, manufacturing and assembly, transport, use, and end of life. The life cycle analysis comprised not only resource consumption and primary energy input, but also six environmental impacts including acidification, eutrophication, greenhouse gas emissions, photochemical ozone creation, resource depletion, and toxicity.
Over the entire life cycle of the lamps, including manufacturing, use, and end of life, the Osram study found that for all three lamp types the use phase dominated the manufacturing phase in terms of energy consumption as shown below.
The other six environmental impacts followed roughly the same pattern as primary energy demand for the three lamp types. The study concludes that less than 2% of the total energy demand is needed for production of the LED lamp, and that the other six environmental impacts for LED lamps were very similar in degree to those of CFL lamps. Osram claims that the study “has dismissed any concern that production of LEDs particularly (sic) might be very energy intensive.”
The Osram LCA of the three lamp types points out that LED and CFL lamps are comparable today in their overall environmental impact, and that both CFLs and LEDs are superior to incandescent lamps. Osram also makes the case that LEDs have the potential for further improvements in performance (~2x) as compared to mature incandescent and CFL lamp technologies. Although proper recycling of lamps was discussed in the summary of the Osram LCA, the toxicity of the mercury (Hg) content of CFL lamps and of mercury releases from coal-fired electricity consumed during all lamp manufacturing and use were not explicitly mentioned in the summary of the Osram LCA.
Taking the results of the Osram LCA at face value, we conclude that efforts in various countries to ban incandescent lamps may indeed lead to significant environmental benefits. While some lighting consumers still complain of deficiencies in CFL lamps, they clearly yield energy savings that will pay for the somewhat increased cost of CFL lamps.
What is not yet as clear are the economic benefits of LED lighting to the broad range of lighting consumers. A check on the web reveals that the Osram Parathom 8 W lamp sells for $54. This is a high cost for lighting consumers to pay for a lamp rated to last 2.5x as long (25,000 hours) as a comparable CFL lamp and having a comparable environmental impact. In their LCA, Osram points out that future improvements in LED lamp luminous efficacy of perhaps 2x are to be expected. We also hope to see price reductions that will make LED lighting still more attractive as manufacturing technology improves.
With LED lamp lifetime of 25,000 hours today and perhaps 50,000 hours or more in future, consumers may think differently when purchasing light bulbs. If LED lamp prices stay relatively high but LED lamps offer long term energy savings that offset their cost, consumers may feel they are making an investment in their future when buying bulbs. However with high-priced, long-lived bulbs new business models may emerge. Consumers may wish to trade in used lamps with say 25,000 hours of life remaining. Or hand down long lived lighting to their descendants. Perhaps a key upside to the adoption of greener and more energy efficient solid state lighting will emerge as consumers pass down their light bulbs to successive generations that live on a cleaner, sustainable earth.