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Lcascupsfig1
Here’s a life-cycle energy analysis on reusable vs. disposable cups -another data set to look at would be from washing a cup in the sink (I have a dishwasher and never wash cups in it) but that said, a lot of people use a dishwasher for everything. There are other factors like soap production, transportation costs, etc too, but then it would be really confusing.

It’s interesting to note that a ceramic cup takes 1,000 uses to break even with foam cups. so, about 3 years if you use a cup every day – that’s not so bad — perhaps someone could make a line of coffee cups that say “use me for 3 years to recoup the energy costs” it would make the cup more important and more heirloom-like. People would try and save the cup for as many years as possible to be efficient. Maybe bight green cups with the date of creation on the bottom.

Someone tell treehugger.

This classic life-cycle energy analysis was performed by University of Victoria professor of chemistry Martin B. Hocking. Hocking compared three types of reusable drinking cups (ceramic, glass and reusable plastic) to two types of disposable cups (paper and polystyrene foam).

The energy of manufacture of reusable cups is vastly larger than the energy of manufacture of disposable cups (Table 1). In order for a reusable cup to be an improvement over a disposable one on an energy basis, you have to use it multiple times, in order to “cash in” on the energy investment you made in the cup. If a cup lasts only ten uses, then each use gets “charged’ for one-tenth of the manufacturing energy. If it lasts for a hundred uses, then each use gets charged for only one-hundredth of the manufacturing energy.

But in order to reuse a cup, it has to be washed. The efficiency of the dishwasher, and the efficiency of the energy system that powers it, determine how much energy is required for each wash.

Institute for Lifecycle Environmental Assessment, thanks Saul Link.

Phillip Torrone

Editor at large – Make magazine. Creative director – Adafruit Industries, contributing editor – Popular Science. Previously: Founded – Hack-a-Day, how-to editor – Engadget, Director of product development – Fallon Worldwide, Technology Director – Braincraft.


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Comments

  1. satype says:

    It seems to me that these results are a bit short-sighted. Their findings are what they are, but we’re well aware that the single use cups usable lifetime is merely a fraction of their life. An analysis of reclamation energy costs for each material would surely offset the hardly recyclable styrofoam.

  2. zzag says:

    Please read the article closer. In my interpretation, it is saying that the energy required to wash reusables is more than the energy to make disposables. The article on disposable diapers has pretty much the same conclusion. Environmentalists will surely shun some of the other articles counter-intuitive to their thinking. Examples: electric cars are worse for the environment than gasoline, and recycling is only worthwhile for materials hard to obtain (e.g. aluminum, steel). The theme is energy use. And energy use = CO2 emission which is the environmentalist’ hot topic. No doubt there is plenty of CO2 emission in debating this topic.

  3. Bozzle says:

    What effects do the disposal costs (landfills, trash collecting) have on this equation? Getting rid of 400 foam cups is not a small matter.

  4. zzag says:

    Good point. And land pollution/land availability is ignored or side-noted in these articles since the theme is energy usage/air pollution. There is an article on that site that does talk about trash collection that I hadn’t thought about… Recycling trucks cannot compact their load (complicates sorting) so they cannot carry as much so they use more energy.

  5. PhoneJef says:

    what is the energy usage of the trucks driving the styrofoam cups to walmart, and then all the consumers driving to walmart to pick up the cups.

    How about the energy for the packaging of the disposables over the packaging of the more durable cups.

    I think the bottom line is that waste is waste. As a modern society we will always be increasing our demand for energy to maintain a modern lifestyle.

    That is why the solution is going to involve cleaner and more renewable forms of energy.

    for myself I’m glad I don’t suffer the irritation of finding a new low energy cup each and everytime I want more coffee

  6. snerdlap says:

    For the individual, the cost-benefit analysis of reusable vs disposable is very complex, as other posters have noted. However as a freelancer I’ve worked at a couple of very huge corporations with subsidized cafeteria. There I noticed people used disposable cups even when eating in, and in spite of ceramic cups being available.

    in that situation its hard to see how the disposables could win up against the economies of scale enjoyed by the high capacity and presumably more efficient washers. In a kitchen serving several hundreds, if not thousands of beverages a day, a cup would hit the break-even point in weeks if not days. I think definitely corporate american kitchens could make more of an effort (like a surcharge for disposable service ware).

  7. meadowlarkb says:

    Paper cups, including waxed paper cups, are generally biodegradable. Some cities collect biodegradeable trash separately and make soil with it. I don’t know how much energy that takes or gives back though.

  8. meadowlarkb says:

    Paper cups, including waxed paper cups, are generally biodegradable. Some cities collect biodegradeable trash separately and make soil with it. I don’t know how much energy that takes or gives back though.

  9. dbri says:

    this article really leaves out what ‘life cycle’ means… go be a janitor for a few months and you will find out.

    the space requirements alone for landfills justify the use of reusable cups. the energy required to transport cups to warehouses, stores, consumers, landfills… and your local sidewalk… are not even considered in this ‘analysis’. the cost of cutting down trees to make a paper cup… another thing not considered… the loss of wildlife habitat, and the loss of a CO2 sink so that we can dispose of cups, the environmental damage caused by dredging up petroleum products that are precursors to styrene and/or plastic,.. i really dont see how someone forming clay into a pot is ‘more impactful’ to the environment than reusable cups. .

  10. Shadyman says:

    I’m with satype on this one.

  11. nategab says:

    In addition to the many other critiques above, it’s worth pointing out that, if you’re looking to buy a coffee mug (or anything else an alternative to using disposables) the thrift store is a great place to go. items there have already “paid” for much of their lifecycle through repeated use. so buying them is much less guilt-ridden from the above point of view than, for example, buying a new coffee mug. it’s also worth repeating, as someone else did above, that the potential for good coffee mugs lasting much longer than is needed to offset the energy costs of disposables is very high. for the same reason, it’s better to buy a thirty year old gas guzzler that will probably last another thirty years if taken care of rather than buying a new Prius, at least in terms of “embodied energy”. the key is ensuring that you buy (or Make!) quality goods the first time, and take care of them so that they can be used by future generations when you’re done with them.

    Finally, I’m not sure it’s helpful, in the long run, to weigh one product’s energy costs against another as this study does. Thinking of an object as “paying” for the energy that was required to make it suggests that the debt can eventually be “paid off”, which it cannot so long as the mechanism (economy) that produces it draw from diminishing resources. So long as new energy and resources are required (rather than energy produced “renewably” and materials reclaimed from old uses), the books cannot be balanced. Just thought that was important to keep in mind.

  12. nategab says:

    In addition to the many other critiques above, it’s worth pointing out that, if you’re looking to buy a coffee mug (or anything else an alternative to using disposables) the thrift store is a great place to go. items there have already “paid” for much of their lifecycle through repeated use. so buying them is much less guilt-ridden from the above point of view than, for example, buying a new coffee mug. it’s also worth repeating, as someone else did above, that the potential for good coffee mugs lasting much longer than is needed to offset the energy costs of disposables is very high. for the same reason, it’s better to buy a thirty year old gas guzzler that will probably last another thirty years if taken care of rather than buying a new Prius, at least in terms of “embodied energy”. the key is ensuring that you buy (or Make!) quality goods the first time, and take care of them so that they can be used by future generations when you’re done with them.
    Finally, I’m not sure it’s helpful, in the long run, to weigh one product’s energy costs against another as this study does. Thinking of an object as “paying” for the energy that was required to make it suggests that the debt can eventually be “paid off”, which it cannot so long as the mechanism (economy) that produces it draw from diminishing resources. So long as new energy and resources are required (rather than energy produced “renewably” and materials reclaimed from old uses), the books cannot be balanced. Just thought that was important to keep in mind.

  13. BillyTheClown says:

    The Horrible flaw in this graph is that the energy cost of the reusable cup is not flat as the graph shows.

    The graph should be increasing for each use. If you assume the cup is used once as stated in the report then the energy is increases with each use since you need a new cup, were with the reusable cup the energy use decreases with each use.

  14. boxcarbill says:

    “The graph should be increasing for each use”

    no. the y axis is enegy per use. how you describe it, your second cup would take twice as much energy to make as the first.
    energy cost (area under the line) does double with non-reuseable cups.

  15. McGyver says:

    The flaw in the analysis is measuring the energy use per cup rather than the cumulative energy use in using and cleaning a cup on a daily basis versus disposing of a cup and replacing it with a new cup. This a classic misdirection, measure the wrong parameter!

  16. BillyTheClown says:

    When using disposable cups the second use does require twice the energy as the first use, the third use requires 3 times the energy as the first use, because you have to use 3 cups. so 3 uses require 3 times the energy to produce.

  17. The overwhelming consensus in sources that go beyond reiteration of the papers is that Hocking’s publications were not comprehensive and were based on outdated figures. Specifically, referring to the reusable vs. disposable publications, the energy efficiency of dishwashers is far beyond what it was and was in 1991. Furthermore, a typical user will use a reusable mug more than once between washings, dividing the per-use impact by a proportional amount each time. Even Starbucks in conjunction with the Alliance for Environmental Innovation has shown the business case and the environmental case for reusables over disposables for single-use in-house to customers not bringing their own mug.

    Another issue is electrical grid assumptions. Hocking’s work, though not exactly representative of the state-of-the-art of LCA at the time, also suffers from common method of LCA streamlining that aggregates energy grid assumptions. If you wash your cup in a grid-connected home with more efficient energy production, the numbers decrease. If washed with a solar water heater hookup, they practically diminish.

    With all due respect, these are societal issues that are complex and extend far beyond the simplicity of his reports. Furthermore, there is a psychological aspect to the choice matrix, where the visibly typical way of doing things influences strongly the current and next generations’ awareness of minimizing resource use – another argument for reusables based in social science as opposed to physical science.