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Thread: ABC article about the environmental impact of drinking coffee

  1. #1
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    ABC article about the environmental impact of drinking coffee

    Gene Cafe Coffee Roaster $850 - Free Beans Free Freight
    Instant coffee is the better choice for your carbon footprint - ABC News (Australian Broadcasting Corporation)

    Title is a bit clickbait-y but overall it's interesting.

    Here's the original article:
    https://theconversation.com/sorry-ba...e-kettle-98754

    Interesting that 'barista's' are mentioned, but there's no mention on the environmental impact of using a home espresso machine...

  2. #2
    Senior Member flynnaus's Avatar
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    Good find. Ok, doesn't provide stats to back up the claim but I'm guessing the cost difference between a cup of instant and a cup of espresso isn't much.
    Most importantly, who's going to switch to instant to save a few cents or cubic metres of CO2, assuming the instant is less? Thought so.
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  3. #3
    Senior Member Lyrebird's Avatar
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    You have to click through one of the references: https://phys.org/news/2011-05-eco-ba...-capsules.html where it appears that a bench top fully automatic machine has a carbon footprint up near the capsule machines.

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    CoffeeSnobs Owner Andy's Avatar
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    Interesting to read but there are a lot of holes in their argument (considering it's our CSIRO that paid for the article).

    "Glass is highly recyclable and not particularly energy-intensive to produce"
    Really? How many times can I boil a kettle compared to the energy input required to smelt glass?

    "Fertiliser is the biggest source of greenhouse gas emissions in regular coffee cultivation"
    Ummm, it might be in large commercial harvested plantations that instant coffee companies use from but the specialty coffee producers and small plot farmers that typically produce all our coffees spend next to nothing on fertilisers and instead put the left-over coffee cherry pulp back on the trees as a natural and near cost-free organic nutrition source.

    "(instant coffee production) beans are roasted and ground, coffee is brewed and then either freeze-dried or spray-dried."
    Brewed! Boiled in hot water before even more energy inputs to freeze dry. That's a lot of energy ignored in the math and instant coffee production would have to use more than twice (maybe 3 times) the amount of energy compared to fresh beans in a plunger and boiling a cup of water once. Show me the Nestle plant's power bill and see how many kettles or espresso machine boilers could be run for the same wattage.

    I can't believe that our leading tax payer paid scientists can get to write fluff like that, I want my hard earned money back.
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    ... and my rooftop solar lets me ignore the "boiling energy required" in terms of carbon footprint - just like over 1,000,000+ homes in Oz and rising rapidly.

    What a load of bollocks.

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    Spot-on Andy...

    Mal.

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    Senior Member gonzob's Avatar
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    I'm one of those nerds that measures stuff.

    There's just me and the missus at home. We use 11.5kWh per day on average. We use about the same energy again for gas (water heating and stovetop cooking)

    When we go away, the house on its own uses about 4.5kWh, so just under half the total power (running fridge, freezer, servers, instant water heater)

    The espresso machine uses 0.5kWh per day. It costs about 15c. I can save more CO2 by pressing my accelerator more gently. Or not turning on the reverse-cycle heating.

    There's plenty of other things to worry about, and you're right flynnaus, who's going to switch???


    As an aside... the effect of converting all our cars to electric.... If that happened, we'd need another 2 times the electric power we generate now. No-one mentions that when they talk about electric cars.

    I'll just get off my hobby-horse now.

    Gonzo
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  8. #8
    Senior Member Lyrebird's Avatar
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    Quote Originally Posted by Andy View Post

    Really? How many times can I boil a kettle compared to the energy input required to smelt (sic) glass?
    About 24, if we are considering weight for weight: it takes about 8 MJ to produce a kg of container grade glass and about 330* kJ to boil a litre of water from 20 oC.

    Since instant coffee is normally made at a strength of about 1% solids, if the container weighs as much as the contents you will use about 4 times as much energy boiling the volume of water required to make the coffee.


    Well you did ask.


    * This is a deliberately very conservative estimate, it would require boiling exactly the correct amount of water with 100% efficiency and no losses to steam. In a real world situation you would expect to use around 500 kJ to boil a litre of water so the multiple would become x 16, similarly once the dilution factor is taken into account it would require about 6 times as much energy to boil the water as to make the glass.
    Last edited by Lyrebird; 2nd July 2018 at 10:11 PM.
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  9. #9
    Senior Member Lyrebird's Avatar
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    Quote Originally Posted by Andy View Post
    Brewed! Boiled in hot water before even more energy inputs to freeze dry. That's a lot of energy ignored in the math and instant coffee production would have to use more than twice (maybe 3 times) the amount of energy compared to fresh beans in a plunger and boiling a cup of water once.
    That would be true if it were extracted at normal strength and none of the energy was recovered but neither of these assumptions holds.

    The strength of the primary extract is very high, around 30% solids. Not even my spoon dissolving ristrettos reach that level.

    Since energy cost is a large part of manufacturing cost, a great deal of attention is paid to maximising efficiency and recovering energy from process streams. In a spray drier, for instance, it is common to use the exhaust to preheat the incoming air.
    Last edited by Lyrebird; 2nd July 2018 at 10:28 PM.

  10. #10
    Senior Member Lyrebird's Avatar
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    Quote Originally Posted by gonzob View Post

    No-one mentions that when they talk about electric cars.
    Except here

    and here

    and here

    and here

    and here

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    Senior Member gonzob's Avatar
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    Quote Originally Posted by Lyrebird View Post
    Except here

    and here

    and here

    and here

    and here

    Yes, I shouldn't have hijacked the thread. However, while all those references mention the effect on the grid, none of them mention the SIZE of the upgrade needed for 100% electric. One says that the grid could "cope" with 25% electric cars. The amount of energy we use while driving is huge and few seem to understand that. That was my issue.

    And I'm not getting rid of my espresso machine.

    Gonzo
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    Senior Member Rocky's Avatar
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    I have an Agronomist friend who is regarded as a world authority in his field. He couldn't get employment with the CSIRO due to funding reductions and subsequent job contraction.(He subsequently had/has many better jobs leading teams in cutting-edge research all around the world) and then I read about a study of groundbreaking significance like this. I am almost speechless.

  13. #13
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    Behmor Brazen - $249 - Free Freight
    Quote Originally Posted by gonzob View Post
    Yes, I shouldn't have hijacked the thread. However, while all those references mention the effect on the grid, none of them mention the SIZE of the upgrade needed for 100% electric. One says that the grid could "cope" with 25% electric cars. The amount of energy we use while driving is huge and few seem to understand that. That was my issue.

    And I'm not getting rid of my espresso machine.

    Gonzo
    G'day Gonzo

    You are forgetting one small detail - every time someone puts solar on their roof these days, they can easily install enough capacity to charge an electric vehicle independently of the grid (and service stations / fossil fuel companies). Adding cheap batteries means charging can be anytime. Both those technologies are becoming cheaper every quarter. Using the EV batteries at night to run the home may also be an option - also potentially without accessing the grid. So called "EV to grid" is ubiquitous as a term in the US mainly because they tend to use large corporate utilities to do things like that. In Oz, largely due to political inaction / confusion we tend to do it "one rooftop at a time" as citizens with a brain.

    This is not pie in the sky - I have a number of friends in the West who do precisely that today. One of them only visits his local service station to check the tyre pressures and has not bought fuel since 2010 (first gen Nissan Leaf). He does over 150Kms per day from the hills down to the flats (CBD) and back up those steep hills in the afternoon when the batteries are partially depleted. His work - a cost accountant - says it all. They are now a three EV family without a conventional car.

    FWIW, I will probably join them after I finish my new build in the next few months - I am adding an extra 6Kw of Solar panels to the existing 3 Kw to do precisely that. My only contribution to the grid after that will be to send them power unless the supply charge ripoff (nearly $1 per day) together with the minuscule 7 cents per Kwh I am paid (yet they have the gall to charge me 32 cents per Kwh - how do you like that markup?) by them becomes uneconomic overall - in which case I will go off grid altogether. The other advantage is to actually have 24 / 7 / 365 power which is no longer the case here in Rocky (try 4 blackouts in a typical month, yet our suburb's demand is actually around 20% lower here now compared to two years ago). I already feel I am paying a premium for a "barely fit for purpose" power grid. Recent talk about privatising the WA grid would mean even less is spent on maintenance and prices will undoubtedly increase even more. That may be another tipping point over here, and perhaps in the rest of Oz as well.

    Not only NREL USA "National Renewable Energy Labs, Golden, Colorado" (where my ex - wife2 did her PHD whilst we were separating - a set of buildings I know like the back of my hand) know the USA grid will cope, but any Oz scientist in the area will say the same thing about the "national grid" (which excludes WA). I wonder what will happen when the demand for power (roughly level in Oz over the last 5 years, despite the population increase) starts to fall dramatically as the balance tilts more towards self generation here? A few weeks ago some Canberra Pollies were wondering if they should add an extra amount to EV car rego as they were not paying the Gov't fuel tax (about 1/2 our fuel bill is actually gov't taxes) - so someone in the ACT can see what is going down - their revenue and their control.

    TampIt



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