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Can Math : recycling vs MPG

by DeAnander Sun Jun 12th, 2005 at 04:09:45 PM EST

The following question was raised in a discussion group online, under the general topic of SUVs and energy wastefulness: how much blame and dislike is it reasonable to attach to drivers of SUVs for their energy wastefulness, relative to other wasteful behaviours? One member said

The rest area near me has enough aluminum cans going into its dumpster to probably run a Hummer 50,000 miles per year on the amount of energy that's being wasted by not recycling them.
or in other words, "people who don't recycle their aluminium cans are at least as wasteful as people who drive Hummers." The related question immediately arose: if you drive your Hummer to the recycling center to recycle some cans, how many cans must you carry to "save" or reclaim as much energy as you have spent by driving the Hummer to the recycling center? At what point is this a negative-sum exercise in absurdity?

Interesting questions, but how the devil can one figure out the answers? Show Me The Numbers!

These are typical of a whole set of questions that in an energy-literate society would be immediately obvious, but in an energy-illiterate (or energy-obfuscated) society are quite opaque. They set me off on a research project whose results are summarised below (many thanks to various members of carfree discussion list who helped with proofreading, math checking, etc). Food for thought. Here's a table of approximate equivalencies -- unit conversions, if you like -- from which we may be able to draw some conclusions:

.4 KWH
BTU to drive HUMMER 10 MILES
(= 1 GAL)
114,000 BTU
(1 GAL)
83.5 CANS
CSE to drive HUMMER 10,000 MILES
(Average American driver's
annual mileage)
84,000 CANS
CSE to drive HUMMER 50,000 MILES
(thought experiment about
rest-area can discards)
420,000 CANS
PER PERSON (1995 datum)
374 CANS
(1995 datum)
99,000,000,000 (99B) CANS
(at 2 cans per person) needed
to drive HUMMER 50K MILES, in 1 year
210,000 PEOPLE
50K miles in one year
1150 CANS
to achieve this rate at rest area
NUMBER OF CSE needed to drive
40,000 HUMMERS
(one years' projected unit sales)
10K MILES per year
3,360,000,000 CANS
NUMBER OF CSE needed to offset
20 MILE round trip
167 (83.5 * 2) CANS
NUMBER OF CSE achieved by
driving 30 MPG car
intstead of 10 MPG car
10,000 MILES
58,450 CANS
equiv to above CSE
156.3 YEARS
NUMBER OF CSE achieved by
not driving a 30 MPG car,
as opposed to driving one,
for one year at an assumed 10,000 miles
333 GALLONS = 27,805 CANS
equivalent to above

And now in English: 1122 people would have to recycle every single Al can they use in one year, to "save" enough energy to offset the energy consumption of driving one Hummer 50K miles. (And those people would have to recycle their cans without incurring any further energy costs, such as driving to the recycling centre or using an electric can-crusher).

If that one Hummer only drove the national average of 10K miles in one year, then "only" 1/5 as many people -- 224 people -- would have to dedicate their recycling lives to compensating for the gas consumption of this Hummer. As my yuppie neighbour memorably said, some years ago "Oh, it's so nice that you're conserving water -- that means we can use more!"

You would have to recycle every Al can you use for 156 years, to produce the same "energy savings" benefit you would achieve by driving a 30 MPG car rather than a 10 MPG car for just one year. Since you won't live 156 years, it appears you'll need a friend or two to participate in this justification of a 10 MPG car :-)

The Hummer driver who drives 20 miles r.t. to recycle cans must carry at least 167 cans per trip to make the "savings" from the cans offset the energy cost of the trip -- for a zero-sum game. The cyclist who eats organic and locally-grown food would have a much higher "profit margin" on this trip (not to mention the benefits of exercise and improved humour) for far fewer cans.

And we are still begging the question of why the H we "need" to manufacture 99 Billion cans per annum to contain watered-down sugar syrups with fizz, produced and marketed via an insanely wasteful web of long-haul transit. We wouldn't need high-tech light containers for drinks if the drinks weren't being hauled by air and truck several thousand miles before reaching their consumers... glass (also recyclable, at lower temps) would work fine if we weren't obsessed with reducing freight weight and packing more cans in each cu ft of container space, or making the containers proof against the violent stresses of longhaul transit and repeated middleman handling. But I digress :-)

Back to the implications of the above numbers: The Hummer driver who thought better of it and decommissioned his Hummer in favour of a 30 MPG compact, would save more energy than he could ever achieve in 2 lifetimes of recycling cans, in just one year of average driving mileage (10,000 miles).

Or looked at another way: if a person could, by reason or wheedling or flattery or shaming or tax disincentives, be persuaded to trade in their 10 MPG Hummer for a 30 MPG compact -- then the carping critic, nagging spouse or preachy enviro who persuaded them to take this step would have achieved 2 lifetimes' worth of can recycling activity in energy savings, in just the first year of that Hummer's inactivity, and the same savings for every year thereafter. That seems worth nagging about.

The person who refrains from driving their 30 MPG car for one year or 10,000 miles, choosing to walk or bike instead, achieves an energy savings in just that one year, equivalent to the average can-consumer recycling every single can they use, faithfully, for 74 years (or an average lifetime).

Likewise the person who persuades, cajoles, bribes, shames, begs or ridicules even one other person to stop driving their 30 MPG car and ride a bike or walk instead, has contributed to an energy savings in the first year that is equivalent to a 74-year lifetime of faithful recycling.

The lesson I draw from this is that it is very much worth our while to make every kind of outreach and effort to "uncool" gas guzzling SUVs and encourage at least a return to moderate gas frugality, and at best, an increased popularity of carfreedom. Each year of the difference between Hummer and subcompact or moped is worth 2 lifetimes of can recycling, and each year of the difference between subcompact and feet/bike is worth 1 recycling lifetime.

The choice of transport we make -- its energy cost -- seems to outweigh the importance of our recycling activity by about the ratio of 1 or 2 lifetimes to one year.

BTW, "recycled" Al cans are not made from 100 pct recycled alloy. some virgin metal is also introduced into the process. the "savings" is a reflection of the percentage of recycled material and the E-cost of resmelting it as opposed to the cost of refining virgin ore. but virgin ore is still dug and refined and smelted in the making of "recycled" cans.

Axiomatically, the savings accrued not not making 1 can will always be far larger than the savings accrued by making 1 can partly out of recycled metal.

Along these lines, Reduce, Reuse, Recycle - in that order.
by Kevin Lyda (kevin@ie.suberic.net) on Sun Jun 12th, 2005 at 11:57:54 PM EST
DeA, fascinating and enlightening - now I am even more glad that I am not using any cans at all. Fresh stuff is healthier anyway.
by Fran on Mon Jun 13th, 2005 at 01:34:23 AM EST
Article in the Guardian today about a "green" SUV. Reading the article, I think that this is going to do more harm than good by allowing people to feel virtuous - "Yes, I have an SUV, but it's a green one" - while it still gives out emmissions roughly equivalent to a Ford Mondeo.

If you read the motoring press then you might believe that the RX400h, with its part electric/part petrol "hybrid" engine, has been sent from above to single-handedly slay climate change. According to much of the coverage, there is no need to feel guilty - if you ever did, that is - about driving an SUV, given that the RX400h achieves up to three times the fuel efficiency of its market rivals and an equally impressive reduction of polluting exhaust fumes. The message is clear: relax everyone, the panic's over. A breathless review in Automobile magazine talks of a car that "accelerates with V-8 gusto and cradles its occupants in leather-lined luxury". The hyperbolic review ends: "The Lexus RX400h provides the well-to-do with a sacrifice-free ride to social responsibility."

The key is in that last sentence: a sacrifice-free ride to social responsibility. I suspect that it will be popular and will be used to counter arguments about driving such monsters.

Emily Armistead, a climate campaigner for Greenpeace, is enraged that sections of the motoring media have hailed the RX400h as a "green" SUV, seeing that its carbon emissions, while lower than its rivals, are roughly equivalent to that of a Ford Mondeo estate. "It has marginally less impact on the climate, but it is demonstrably not a green car," she says. "You're still driving two tonnes around unnecessarily to do the shopping." Armistead points out that the differential in Vehicle Excise Duty between SUVs and cars is tiny - about £100 a year. When you consider that it can cost £1,200 to get new tyres for a Range Rover, this is never going to persuade their owners to consider more fuel-efficient, less polluting vehicles.

The article is here: http://www.guardian.co.uk/transport/Story/0,2763,1505293,00.html

by Boudicca (badgerval at hotmail dot com) on Mon Jun 13th, 2005 at 01:40:46 AM EST
It's not even an off-roader. It's simply conspicuous consumption.
by Colman (colman at eurotrib.com) on Mon Jun 13th, 2005 at 02:35:51 AM EST
[ Parent ]
Hey, this is just the sort of computation I would like
to be able to do "spontaneously"!   How about
more along these lines, i.e. more about how to make
"back of the envelope" energy use and efficiency computations.  I'm sure I'm less "rigorous" than Deanander (I still want to be able to take an
occasional vacation flight), but it seems clear that
D's basic outlook is destined to become the common
coin among the minimally informed over the next decade
or two.  (Longer term, I suspect that vegetarianism
will also become the rule, for similar reasons, and
there too I confess to being irremediably archaic.)

Hannah K. O'Luthon
by Hannah K OLuthon on Mon Jun 13th, 2005 at 02:27:09 AM EST
I do hope it will encourage vegetarism, hopefully even soon. And I am convinced that would help to solve part of health care problems and costs,
by Fran on Mon Jun 13th, 2005 at 02:36:41 AM EST
[ Parent ]
I'd be happy if it encouraged treating meat as a luxury to be respected, rather then an industrial product.
by Colman (colman at eurotrib.com) on Mon Jun 13th, 2005 at 02:55:03 AM EST
[ Parent ]
Meat and fish are different from
fruit and grains, but, like many others, they
are just something I pick up at the market.
If I had to hunt or fish for my victuals I would undoubtedly have different views, but I'm not
sure I'm ready to throw the industrial baby out
with the Macdonald-land bath.

Hannah K. O'Luthon
by Hannah K OLuthon on Mon Jun 13th, 2005 at 03:19:42 AM EST
[ Parent ]
I'm trying to drown that particular baby, but it's difficult. In order to get organic/free range meat I pretty much have to drive to the shopping centre rather than go to the local butchers. The local supermarket has a crappy range of vegetables, so that I end up buying meat more often than I would like to in order to get something interesting to eat. Do I buy supermarket veg and butchers meat or do I drive (my small car) to the shopping centre more often?
by Colman (colman at eurotrib.com) on Mon Jun 13th, 2005 at 03:24:28 AM EST
[ Parent ]
By industrial I mean the drug fuelled factory farming rather than more traditional methods. I'd rather eat an organic chicken once a month than buy the cotton wool that comes out of the factory farms.
by Colman (colman at eurotrib.com) on Mon Jun 13th, 2005 at 03:26:35 AM EST
[ Parent ]
A fantastic start on an excellent theme! The Show Me the Numbers approach is a great way of bringing clarity to a lot of issues.

I'm looking forward to the next installment.

The fact is that what we're experiencing right now is a top-down disaster. -Paul Krugman

by dvx (dvx.clt št gmail dotcom) on Mon Jun 13th, 2005 at 04:40:41 AM EST
But in the United States, the systems that manufacture the cans, and those that fuel the Hummer, are unrelated.

Yes, there's a tiny bit of oil in our electrical grid (2.X% and falling), but almost all of that represents small local energy "campuses" (like universities and hospitals), or generators used for emergency power.  The primary electrical grid is driven by coal, nuclear, and hydro, with natural gas picking up almost all of the rest.

You could recycle every can in the country, and it would indeed be a great savings on our electrical grid (and a very good idea for both the economy and the environment).  However, it would not generate one single drop of oil.

The US energy crisis has to be solved by tying the two systems together.  Right now, 95% of oil goes to transportation.  Unless we move vehicles onto the grid, we can never expect to be free of the need for vast amounts of imported fuel.

by Devilstower on Mon Jun 13th, 2005 at 06:34:42 AM EST
Good point, DT.  I was going to brag about having put a deposit on a Toyota Highlander hybrid (t0 replace my 19 mpg VW Passat wagon/combi), but I'm afraid I'd get grief for only reducing my emissions by about 1/3.  I'd like to use a conversion kit to PHEV (plug-in) as soon as it's available.  I'll replace the other vehicle, a Toyota Camtry, with a hybrid when the time comes.

"We're all doin' what we can...", pun intended( Lennon-McCartney, "Revolution")

"I don't belong to any organized political party - I'm a Democrat." - Will Rogers

by tom 47 on Mon Jun 13th, 2005 at 08:30:37 AM EST
[ Parent ]
We have curbside pickup here in my small California town. You should demand this.
by capslock on Mon Jun 13th, 2005 at 10:42:01 AM EST
Aluminum is largely manufactured where there is cheap, abundant power. For example, in the US much of it comes from Washington State, using hydropower from the Columbia. While this has consequences for salmon, it's not directly contributing to greenhouse gasses.

If we go to hydrogen-fueled vehicles, such power sources could be used to produce hydrogen, so the use for aluminum would be competing with that. But at present, there's not so much other use for that clean power. Transmission losses to send it cross-country to where coal plants are the main power source count against direct substitution of hydro for coal, for instance.

Is the situation similar in Europe?

Their freedom lost, all virtue lose. - Milton

by Viktor Runeberg on Mon Jun 13th, 2005 at 11:29:37 AM EST
Great article, overall.  I've often wondered at the energy input required to recycle cans and bottles.

I have a few counterpoints to raise, however.

We wouldn't need high-tech light containers for drinks if the drinks weren't being hauled by air and truck several thousand miles before reaching their consumers... glass (also recyclable, at lower temps) would work fine if we weren't obsessed with reducing freight weight and packing more cans in each cu ft of container space, or making the containers proof against the violent stresses of longhaul transit and repeated middleman handling.

I think you harbor a misconception as to the average distance a canned or bottled beverage travels prior to reaching store shelves.  Bottling is a regional business, because the volume is there to support a fully distributed production network for mainstream drink products.  It's extremely rare for mass-market drink products (e.g. Coke, Pepsi, et. al.) to travel more than a few hundred miles to retail distribution points -- and that's by truck, not by aircraft.  This is true around the world, in any industrialized nation, not just the US.

Also, and I realize that the focus of your diary was energy rather than refined materials, I note the curious omission of the wastefulness of depositing refined metals (which are in easily-reusable form) into landfills.  A holistic view of the process would incorporate the energy input and environmental impact of: mining Al ore, refining that ore, and manufacturing a new 'virgin' can from the resulting Al stock.  

I find it difficult to believe that a pervasive can-recycling system (such as the one we enjoy here in the California SF Bay Area) could fail to yield a net energy savings AND a net improvement in environmental impact compared to the full-cycle process required to manufacture a new can starting with ore in the ground.


by AlphaGeek (SiliconValleyAlphaGeek(a)gmail.com) on Tue Jun 14th, 2005 at 12:20:31 AM EST
DeAnander...this is such an iteresting topic. You could
say that I am energy illiterate..hope to change that soon.

What happened to my tail?
by Eyore on Tue Jun 14th, 2005 at 06:58:45 AM EST

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