Dollars and Fridges


I’m using a really old fridge/freezer. Really old. I wanted to investigate if it would be worthwhile replacing it with a more energy efficient model. After the hot water heater this is one of the bigger power users in the apartment. I have been measuring the power use over the past few days using an MS6115 plug-in power meter. I will elaborate more on it in a later post.

I worked out the average daily power use for this fridge to be about 1.4 kWh. This does not take into consideration how many times the door was opened, if new items were stored or what the ambient temperature is, but it gives me a good idea to work from.

I received this fridge for free so it cost me nothing apart from transport. If I take a look at a similar fridge a few minutes of research comes up with the Samsung SR227MW. This fridge uses 280 kWh per year, or about 0.8 kWh per day. This is approximately an 80% improvement in efficiency. For this improvement I need to pay $566 and get a 2 year warranty.

Is it worthwhile replacing my fridge with the more efficient new one? I have the following information:

Current fridge usage 1.4 kWh per day
Electricity price 23.8 c per kWh
New fridge usage 0.8 kWh per day
Cost of new fridge 566 Dollars

With this information I can workout the payback period. The formula to determine this is reasonably simple.

Break\, even\,(days) = \frac{Cost\, of\, new\, fridge}{(Current\, fridge \, usage-New\, fridge \,usage)\times Electricity\, Price}

This gives me a total of 3970 days or 10.9 years before the savings of the new fridge have paid for itself. If I consider that my current fridge is possibly older than I am and is still working, compared to a new unit that only has a 2 year warranty this does not seem like a good idea.

What people often don’t realise is that all objects have another energy aspect attributed to them. This is called embedded energy. This refers to the energy needed to manufacture the item in question. The diesel to mine the steel, the coal to melt the steel etc. I will discuss this in a future post.

With all this taken into account replacing my working fridge just does not make sense.

7 Replies to “Dollars and Fridges”

  1. Hi Marcu,

    We studied such dilemmas in engineering economics. Another method for deciding this:
    Cost of capital vs Savings of purchase.
    If you have the purchase price of the new ‘fridge, then the cost of investing the money in the ‘fridge is the lost advantage of investing the $566 elsewhere, usually measured as interest lost. Currently a $500 Certificate of Deposit might optimistically earn 1% per year. So then the question becomes if you can save more than 1% of the new fridge purchase price price in electrical savings each year. If your new fridge saves (1.4-0.8=) 0.6 Kwhr/day * 365 days/ year * 0.238 dollars/ Kwhr = $52.12/yr. Now $52.12/$566 = 9.2% per year return if you buy the new fridge, versus 1% return on the $566 if you leave the $566 in the bank -> Buy the ‘fridge.

    But what if you don’t have the cash, and have to borrow the money on a credit card, at 18% interest? 9.2% Don’t buy the ‘fridge.

    There’s other ways to compute the worth of a purchase decision, like internal rate of return.
    Just for chuckles, a payback period of about ten years is about equal to 10% return every year, so our two calculations aren’t too far apart.

    For what it’$ worth 😉


    1. That’s a very interesting point, the economic perspective. I want to discuss it a bit more later, but for me one of the main motivators is the embedded energy costs embodied by the fridge, or whatever you are evaluating. The best case scenario is if the economic argument points you towards using something for as long as possible so that the embodied energy gets as much use as possible.

      Thanks for the comment!

  2. Marcu — re: your old fridge, your payback equation also assumes that it will still be working after 10 years. Since planned obsolescence engineering seems to mean they all die within a decade — cha-ching! for Samsung et. al. — you’re likely to have to replace it anyway with that one whose energy costs you calculated. Perversely, this make it more sensible to hang onto the old free one until it croaks. You’ll have to spring for that SR227 soon enough; why rush it for maybe two years of electricity savings?

    There’s also the matter of hedonics when buying a new refrigerator or anything else. I don’t know about your old one, but will a shiny Sammy have better shelves, an ice maker or other more-modern bells ‘n whistles? It won’t have years of accumulated spills and mould in all those places we MEAN to clean, but never do. Especially not someone else’s bacterial micro-flora! (As a nurse, I’m squicky about germs. All of us are walking bags of anthropathogens, you know…)

    Lastly, on embedded energy, I had a mate in my anti-nuke group the first time I immigrated here who used that concept to argue that the Prius my ex and I owned was LESS enviro than a Jeep. Because of the energy necessitated to mine and refine the lithium for the hybrid’s batteries, the entire development cycle of the car’s engineering vs. the old, amortised technology of the Jeep, yadda yadda. (“Yadda yadda” being a Seinfeld phrase. Did English-speakers in South Africa watch “Seinfeld”?) There was a study in the mid-2000s that used such sophistry to make that “Priuses are bad for the planet!” case. Needless to say, we didn’t run out to trade the Toyota for a Wrangler. I think the quibbling bloke was just jealous because he didn’t even own a vehicle and was working as a part-time bookkeeper for his mum while living in a unit that his family owned, while we were enjoying the cashed-up existence of expat Yanks, so he was keen to take us down a notch. But that’s another tangent.

    1. This fridge has been going for at least 25 years so I would bet on it making 10 years rather than any new fridge. Here is an article I came across recently discussing this topic and going into the details: ​​They Used To Last 50 Years
      ​I agree that my options will be limited once this one is beyond repair but I will hold out for as long as possible.

      The “ick” factor together with hedonics are a strong motivator. I don’t see, however, how it is justified buying a new fridge just because you can’t get yourself to clean your current one. ​

      ​Regarding your Prius – I will leave you with this article, ​Unclean at Any Speed and let you decide.

      We most definitely had Seinfeld, but I was a bit young at that point…

  3. Thanks for the linx, Marcu. The “Unclean” piece was a rehash of the basic premise that my anti-nuke mate pointed me to in 2006, with more updated numbers and technology. No such thing as Tesla then! I won’t get bogged down with quibbling to pick its points apart, just mention two things.

    These articles that mention the upstream environmental impacts of lithium battery production, etc. neglect to apply the same standards to production of the fuels that power internal combustion vehicles. What went into drilling the oil well (or tar sands moonscape), transporting the ooze, refining it and then trucking it to the bowser. (Do they use that word for petrol pump in SA? It seems a quirky Australianism, although maybe it’s British. I enjoy the local Strine lingo. Canada didn’t have many of its own words, which is understandable, since it’s culturally dominated by the 800-pound/400-kilo gorilla next door.)

    There are the inevitable oil spills, plus the toxic byproducts of oil refining. The author writes about the bad side of making solar cells while “lying with figures” about the 23,000% greater greenhouse gas effect of sulphur hexafluoride. He neglects to say how little MASS of gas is actually produced that way because there’s not tonnes of SF6 it in every car. Oil refineries and petrol stations will also have to be dismantled, at an environmental cost.

    I could go on all day, but I’m getting bored of myself, so I can only imagine where your head’s at. What someone chooses to include or ignore in an article like that depends on the biases one comes in with. And we’re ALL biased in some way.

    Point 2 is that the “Unclean” author barely alludes to cars whose batteries can be trickle-charged by photovoltaics. If there’s going to be individual car-driving in the future, I reckon that will be the go. Vehicles would resemble go-karts, instead of the relative behemoths that even electric cars are now. A tonne of car for every 100 kg of human that’s riding around, WTF? If the world (especially the U.S.) had devoted as much brainpower to building better batteries as it did on intercontinental ballistic missiles during the past half-century, we’d be SO much better off.

    Although I’ll argue the point in favour of electric cars, I didn’t buy one when I came back down here. I let my ex take the Canadian Prius without a second thought when she scuppered to San Francisco (a week after I made the final payment on the thing.) I lived there for a year getting around on my bikes and public transport. I don’t live this way for financial reasons. I’ve lived wisely and handled my money well, so I can afford to buy anything I want, in cash. Fcuk debt — I got none of that chit! I choose to live in a lower-footprint way because it’s the morally right thing to do, just as exiting the Amurderican Empire was.

    That said, each time I fly to the U.S., which I do every year or so because all my family lives there and I enjoy seeing my grown-up daughter, that negates the entire amount of carbon I’ve saved by using my bike, the trams and trains.

    You read James Kunstler, right? I agree with his scorn for techno-utopians. Elon Musk is not going to save us. Priuses, Teslas AND hulking SUVs driven by tiny frightened blonde women are the shiny bagatelles of a dying civilisation. Collapse is coming, inevitably. The future is going to look more like Cormac McCarthy’s “The Road” than Esso Corp’s “Happy Motoring.”

    When you get right down to it, everything we humans do fouls the environment. The only human who’s not polluting is one who’s dead. By hanging, seppuku or jumping off a high place (NOT into the water, unless there are a lot of crabs around, ’cause waterlogged rotting flesh is toxic), please. Gunshots release noxious gases and there’s that bit of lead lying around after it’s gone through your brainpan…

    I don’t intend to go that way. I’m having a great time being alive, and I’m going to string it along as far as my lifespan or the course of human events will allow me. While doing what I can to educate the people around me, and being nice to folks where I can. Greer had a snark a couple months ago at people like me who are going to ride this puppy down until it crashes and burns. I don’t do it with selfish, ghoulish glee, though. More with a sense of sadness, like when I’ve worked hospice cases while doing home health. Death comes to us all, even our way of life. The point is in trying to live as kindly as possible under the rules of the game we must play. Which, in 2006 and 2009, included buying Priuses here and in Canada. Something I don’t regret.

  4. Also, since that comment was too long-winded (my first career was as a newspaper reporter for 10 years, so I tend to crank out words like a mofo) I liked the appliance article. Mainly because it reinforces my bias against rapacious corporations. Rapacicorps! Sounds like a species of dinosaur. When really, a corporation is a vampire, undying, soulless, feeding on humans to be the cells of its body…

    Unlike the car article, there was a lot of info that was new to me in that one. I’ve known about planned obsolescence since I was in high school, and read accounts of Henry Ford sending researchers into scrap yards to see which parts of Model Ts looked newest when the rest of the car had died — a sign that they were building that part too strong! I’ve joined with many people bemoaning the fact that refrigerators crap out after a decade or less. Why? Rhetorical question, of course — so they can sell us more!

    The specifics, though, such as the thinner paint layers, predictably breakable parts made out of plastic, etc. — I didn’t know the nuts and bolts. (Pun intended.) As I was reading it, I had to get up and touch the door of my fridge (a Westinghouse, bought last year, because that’s the last brand made in Australia, although they’re winding it down to be made overseas too.) It’s smooth, not nubbled, hooray!

    I haven’t bought a washing machine or dryer for my flat yet. It’s SUCH a commitment! Even at a decade’s life, that’s longer than a lot of marriages. Like to my first ex… I’ve been leaning toward Miele. No racism implied, but screw buying anything made in fascist China if I can help it. I don’t mind paying $2K + apiece for them if I’m not playing into the sucker’s game. You know any dirt on the West German firm?

    One of the reasons I’m not totally bummed about Peak Oil (I still believe!) is that when it makes transportation costs for stuff manufactured halfway around the world LESS than negligible, industrial production will have to be done closer to home. And maybe it won’t all be junque, because society won’t be able to continue at the current level, replacing every household machine every decade in a world where every input has to be carefully considered.

    The dynamic mentioned in that article is “anti-hedonics.” Instead of modern things functioning better, they’re engineered to be WORSE, because profit! I bet the cooked government inflation statistics don’t take THAT into account, the way they do when calculating that TVs are cheaper than ever because of the bigger screens and higher pixel densities. I wonder if John Williams at ShadowStats makes the anti-hedonic case?

    The “trap you into buying crap because ALL the members of the oligopoly have colluded to do it” zeitgeist is one of the reasons why I get along well with the paranoid schizophrenic conspiracy theory mental patients. Not because I agree with their delusions. I suggest as gently as I can that there are not mind control transmitters implanted in their walls by the Illuminati, so they don’t need to punch holes through the plasterboard looking for them. Because even if such things DID exist, you, Mr. or Mrs. Mental, are not important enough in your dole-collecting lifestyle, to be worth the trouble to any mystical entity. Logic has never worked on any of ’em, though, and I’ve met hundreds.

    When you think about it, you have to be MUCH more invested in believing something outlandish than following the conventional wisdom. It’s easy to follow what the herd believes. But to espouse something that’s bat-crap crazy, you gotta be well and truly into it.

    Anyhow, what I like about some (but not all — many are paranoid in conventional ways) of the schizos is that they’re willing to think outside the box. They don’t reflexively dismiss the idea that corporations are colluding to crapify our lives. When I go on an anti-Big Biz rant to friends and co-workers, most of ’em think I’m a trifle tetched. And I’m not a wild-eyed table-pounder. More of a sardonic snarker. The me who was eating a pizza covered in spinach was who I really am. Parts of my mental Venn diagram overlap with the loonies. They appreciate a nurse who can discuss the details of their kooky theories.

    I know most of them, but every once in a while I’ll get surprised by one such as The Boule — African-American Skull and Bones-style secret demonic society — Obama’s one, doncha know?!? ?snark? or The Yinon Plan. That’s a purported conspiracy by Israel , circa 1982, to destabilise Muslim nations around it so they fall into anarchy and cannot threaten the Jewish State. Events DO seem to be trending that way, thanks in no little measure to the U.S., but the people who spout that shit are typically the most revolting Stormfront-style anti-Semites. Are you Jewish? My best South African friend Down Under is, and so is my dentist. They and their families were under a double onus when the apartheid scum fell, so they fled here.

    Because my first ex’s dad and mom were Jewish emigrants from Belorussia (she was a hippie who renounced organised religion, though) my daughter is technically Jewish. Not that there’s anything wrong with that! “Seinfeld” again. The catchphrase source for my generation.

    Whoah! Where did all these words come from? My fingers tend to ramble more than my mouth. Time for dinner.

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