Wednesday, November 30, 2011

Turn Off, Replace, or Trudge Forward?

Buying newer more efficient appliances and lights is one easy way to achieve energy efficiency. But is it always the best choice?

Replacing appliances and things has an impact too. Something is going to happen to the old stuff, plus there are pocketbook and lifecycle costs associated with the replacement.

My last blog post encouraged people to replace incandescent Christmas lights with new LEDs. In response, JMR raised a really good question:
Thanks for the info Tamara. I think the energy savings of LED's are great... and I think there is going to be a lot of waste in the world if everyone throws out their holiday lights. How do you balance this need to limit energy consumption while equally limiting waste and unnecessary consumption.

I'd like to tackle a couple ways to look at this question of keep versus replace.

The first option is simply to do without Christmas lights. From a consumption or environmental point of view, going light-free is a hands down winner. That said, it's not for everybody. Instead of being the Party of No Fun, my hope is that people are drawn to all the "Yes, and" choices that are opening up because manufacturers are offering so many greener choices.

If you want lights, then I conclude that replacing is the better option from a money and environmental standpoint. The short version is that strands of lights don't produce much waste, the energy savings is significant (on the order of 70 - 90% improvement), and the replacement cost is small. Other situations are tougher -- Like should I replace my 10-year old, perfectly fine 27 mph car with a new or newer hybrid or all-electric?

For a lot of materials, the biggest lifecycle impact is in resource extraction and production. For those, the scale tips toward keeping them. In the case of the holiday lights, my understanding is that the bigger impact occurs during actual use, so the scale weighs toward replacing.

Do you agree? Disagree? I welcome people to share ideas around how they make sustainable choices. We could learn so much from each other.

Those who like short answers please STOP here.

If you are interested in the long, info-nerd version, then read on...

One could look at it thru a garbage lens. A bit of personal history you may not know is that I spent many years working in the waste arena and can talk in depth about US and Canadian waste prevention, recycling, commercial scale composting, incineration, energy recovery, landfill, transfer, and collection issues. I've been a regulator, a regulatee, an operations manager, an environmental manager, and a technical consultant/policy advisor. What we learned when creating state and local waste prevention and recycling programs and designing and retrofitting safer disposal sites offers useful lessons for today's efforts toward energy efficiency,alternative energy, and wise management of other energy sources.

Tossing perfectly functional lights is indeed wasteful. The bright side (no pun intended) is that the amount of waste is small and the material are not toxic. While the glass and metal components are technically recyclable, unfortunately there is no market for old light strands to make recycling happen.

Working lights could be donated to Goodwill or re-gifted, but it is reasonable to ask whether it is really better for the environment to shift the energy hog problem down the line to somebody else. Programs like Cash for Clunkers looked at the same problem for cars, and decided to take gas-guzzling polluters off the road once and for all. You can find similar incentives to put old energy-hogging refrigerators out of service too.

It took several hazardous components to make the lights, but those chemicals are pretty well bound up and will not produce measurable impacts as they take hundreds of years to degrade in a landfill. If they were to end up in an incinerator, the plastic portion would help by adding thermal content, but the metal would be released. A large portion of the metals will become bound to particulate matter, and, depending on the type of pollution control system, a large portion will become part of the non-hazardous bottom ash and a smaller potion will show up as hazardous fly ash. The glass becomes slag. Over time, slag builds up to be an expensive maintenance headache. In this case, the glass volume is too tiny to matter. There would be air emissions of metals and plastic components, but, again, they would be too small to measure.

Another way to compare the impact would be to estimate the environmental cost of kilowatts saved vs. kilowatts burned and compare that to the environmental cost of buying new lights plus disposal of the old ones. The best methodology for this is probably a combination of Lifecycle Assessment and looking up emissions factors. I did compile a comparison of Lifecycle Assessment Tools once, but there are people far better suited than me to actually perform the complicated analysis.

As far as non-emissions impacts of energy, one could consider that hydro damages rivers, commercial and non-commercial fisheries, and has other habitat impacts, and mining and transporting coal has large impacts as well. In one sense, the non-emissions impacts could be considered "sunk costs". In other words, the incremental energy difference associated with my lights won't change them because the damage was already done.

If that is true, then I could focus on emissions from using energy as the most relevant way to differentiate between keeping or replacing. Energy emissions factors vary depending on the energy mix where you live - In my area it is 48% coal and 52% hydro. As such my power has lower emissions than it would in places that are more fossil-fuel dependent. Even so, burning coal pollutes. It puts out CAPS (Common Air Pollutants) like Carbon Monoxide, Ground-level Ozone, Lead, Nitrogen Oxides, Particulate Matter, and Sulfur Dioxide, HAPS (Hazardous Air Pollutants) like Metals (Mercury, Arsenic, Chromium, Nickel, etc.) Volatile Organics, Acid Gases, and Greenhouse Gases.

There are pollution numbers associated with waste disposal, but there is not a way to relate a particular piece of waste to downstream emissions. I can confidently say that the numbers involved are very, very small, but I can't tell you what they are. Lifecycle analysis can shed light on the impacts of producing the new lights. The impacts are real, and should definitely be considered.

My best estimate is that the impacts of disposal and consumption are dwarfed by the ongoing impact of burning excess energy for this particular situation. That is not always the case though. Like JMR reminds us, asking whether to replace or to keep is always a good idea. For a lot of materials, the biggest lifecycle impact is in resource extraction and production. For such items, the scale would tip toward keeping it.

2 comments:

  1. I have discovered that many places will "recycle" old strands of lights which seems to mean that they take your old strands and recycle the copper wire inside them. Here is a holiday light recycling page for Seattle. http://atyourservice.seattle.gov/2010/12/22/christmas-light-recycling-locations/ People live in other places can google to find light recycling centers in their locations. These efforts tend to be seasonal so you want to do it soon or wait until next November. This past November Home Depot had a promotion for a Christmas Light trade in program in November where you could bring your old strands in for recycling and get a discount on new LED lights.

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