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LED Life Cycles

By: Cary Weiner

The U.S. Department of Energy projects that LED lighting will achieve 48% of all lighting sales by 2020 and 84% of sales by 2030 (as measured in lumen-hours). Considering sales of LEDs in the U.S. already hover around $30 billion annually, it’s not a bad industry to be in! So there are and will be a lot of them out there – in homes, businesses, and industrial applications – and they’re supposed to live long. And I mean looooonnnnggggg. As in, “if you turn on an LED household bulb for 4 hours per day, it should last you 34 years” long.

Of course, as with compact fluorescents (and most things we buy these days), you’re bound to get a dud. So it’s only natural that we ask ourselves what we’re going to do when all these new bulbs go dim. (Which is just a figure of speech – actually LED brightness levels don’t dim dramatically before they simply stop working.)

First, it should be known that LEDs can be disposed of in the regular trash. Because they do not contain mercury like CFLs they are considered to be routine waste products. But that doesn’t mean we should necessarily fill our landfills with them. By mass, a typical household LED bulb (A-bulb) is:

  • 42% aluminum cooling body
  • 21% plastic housing
  • 16% driver electronics
  • 15% glass globe
  • 4% LED modules
  • 2% socket/contact plate

In the U.S., recycling aluminum, plastic, glass, and electronics is nothing new. However, the LED modules themselves are made up of rare earth elements like europium as well as small amounts of indium, gallium, gold, silver, and other materials. While gas discharge bulbs (i.e. fluorescent) are recycled somewhat crudely to capture the value of the glass, the presence of high value materials in LEDs speaks to the need for a more sensitive recycling process that remains under development. Because of this, if your recycling company even accepts LEDs they are likely just holding them until technology develops that allows for the cost-effective extraction of the high value materials.

You may also wonder, with aluminum, plastic, electronics, precious metals, and rare earth minerals making up a higher percentage of LED bulbs than gas discharge bulbs, do the environmental benefits from increased efficiency still outweigh the costs of extracting these resources? Funny you ask! According to a 2013 study by the U.S. Department of Energy, the environmental benefits of modern LEDs over their life cycles are far greater than the benefits of CFLs, which are themselves many, many times environmentally friendlier than incandescents.

LED life cycle impacts

 

 

 

 

 

 

 

 

 

 

 

 

The study notes that the LED bulb’s main environmental drawback is its aluminum heat sink. Apparently the mining and processing of aluminum is energy intensive and generates sulfuric acid and other hazardous byproducts. Of course, these impacts will be reduced if and when cost-effective LED recycling technology is developed. Luckily, their long lifespans are buying researchers some valuable time.

References

“LED Lamps Recycling Technology for a Circular Economy” (August 25, 2016). LED Professional Review.