Light Bulbs: Life Cycle Assessment

Assessing products is complicated.  A complete life cycle story starts with the extraction of the materials, the manufacture, the distribution and then the disposal.  We look at all of the environmental impacts, on air, water, soils, human health.  This sum total is divided by the service life of the product.  Clearly, a long life is better – as the “harm” per year is lower.

In the case of products like light bulbs, the energy consumed is also part of the equation. Not only the actual quantity of the energy consumed, but the source and distribution.  So there is really no way to have a definitive life cycle analysis for any particular bulb,  but we can deal in generalities.   Since 48% of the electricity generated in the US is from coal-fired plants, then we need to include the methyl mercury, the most toxic form of mercury, released into the atmosphere and absorbed into the bloodstream through our lungs.   If we were assessing lightbulbs in Iceland, where the energy is from geothermal, then this equation shifts dramatically.

Tradeoffs between materials hazards and pollution from energy are a reality of modern life.  The only non-toxic source of light is the sun.  

Last year, there was a study by UC Irvine’s Department of Population Health & Disease Prevention, which warned us to be vigilant about the toxicity hazards of those marketed as replacements for lighting products that do not deplete energy resources or contribute to global warming.   That point was well taken, but the research created a toxicity scare which was not in keeping with the actual research.  For example, the testing was done on LED bulbs which had been pulverized for the mineral leach test.  Not likely this will ever happen in real life.  Yes, there are rare earth metals, such as copper – which is used in pennies, copper wiring and piping. The devices studied were raw T1-3/4 LEDs, which does not have the same device architecture as lighting class LEDs, resulting in a much higher lead-content testing.   So while the news hysteria was overblown,  it is also incorrect to state that LEDs are non-toxic .  They should be recycled with toxic materials.

Fortunately, our government laboratories have been hard at work in studying the life-cycle assessment of LED lighting products, and just issued the final report last month.    The 78 pages are packed with solid facts concerning the manufacturing, the environmental impacts, pollution costs of energy sources and software comparison packages.  The data is based not only on current state of the art, but projecting out the current technology advances of LEDs into 2017.  The radial diagram says it all (above).    The point of comparison is a standard incandescent bulb, the blue line at the outside of the spider diagram.  CFLs and current LEDs are both much better, but relatively close to each other.   However, the real point news is the purple line, which is the LED 2017, which is where these bulbs are heading.   The controversial  ‘lightbulb’ bill HR2417 is calling for a reduction of energy in light bulbs of 70% by 2020.  According to this data, the LED 2012 is already at 76% energy savings, while the LED 2017 is projected to save up to 88%.

It is complicated and it has been a wildly unregulated market. Some of the products coming out of China were far underperforming the potential.   So I am glad the DOE has taken a stance, and is recommending actively working with manufacturers to meet the targets for efficacy and performance, and support the US industry establishing an ICC standard for manufacturing QC accountability.

Now -  I should go to bed and turn off all these toxic lights, since the sun went down hours ago…