• WhatAmLemmy@lemmy.world
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    1 year ago

    I think they look the opposite. They don’t just reduce land usage, but also the amount of water, pesticides, fertilisers, carbon / transportation, and waste (longer shelf life due to less transportation time); plus they’re less susceptible to the local climate variability, which will become increasingly necessary at we blow past 1.5c and agricultural yields deteriorate.

    They’ll be huge once they mature and are 100% powered by renewables.

    • bluGill@kbin.social
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      1 year ago

      It is very hard to compete with regular crops outdoors that get free sunlight on cheap land. Any light these get is taken by shadowing something else. I’m not saying there are no niches where this can work, but as a.niche there is a.limit.

      • theluddite@lemmy.ml
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        1 year ago

        Yes exactly this. Indoor farming uses many, many orders of magnitude more energy than traditional farms. Low-Tech Magazine (one of my favorite publications on the internet) did a write up where they discuss actual experimental results on how much more land solar powered indoor farming uses than just traditional farming.

        If we use their energy measurements for vertical farming, and compare them to published amounts of fuel used per acre of cereal crops to get a rough comparison, we conclude that vertical farming is about 157,827 more energy intensive than traditional farming — a whopping 5 orders of magnitude.

        • HubertManne@kbin.social
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          1 year ago

          cereal crops? Most implementations of these that I am aware of are greens that are being grown in a metropolitan area in order to be close to point of sale. The idea is it is clean and does not need to use pesticides and such. So it is equivalent to the most premium of greens. Pluse it does not get the ecoli contamination that happens way to often with greens. Then there is the water intensive nature of greens which is easier to minimize water with these setups. So it would be interesting to see the comparison with greens rather than cereal.

          • theluddite@lemmy.ml
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            1 year ago

            Cereal crops are just the information that’s easily available. It’s not a perfect comparison, but still, 5 orders of magnitude is a shocking result. That’s the average American’s daily commute distance vs the distance to Venus. Any reasonable use of indoor farming must somehow overcome how mindbogglingly energy intensive it is.

        • PopOfAfrica@lemmy.world
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          1 year ago

          Woulf shipping offsets not be even to even things out, assuming we use these for local supply chains?

          • theluddite@lemmy.ml
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            1 year ago

            No way. Shipping things to market once uses very, very, very little energy when compared to continuously replicating the sun indoors with artificial lights for months.

            • kozy138@lemm.ee
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              1 year ago

              I think you’re underestimating the time and resource impact of transporting tons of food, often refrigerated, from the middle of nowhere to dense urban centers.

              With enough renewable energy, the emissions cost of replacing the sun indoors could be zero.

              • theluddite@lemmy.ml
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                1 year ago

                No, I’m not. Moving things, even refrigerating them, takes so, so, so much less energy than replicating the literal sun for months. The sun gives you approximately 1,360 watts per square meter. That’s 117 million Joules of energy per day per square meter for the entire area of that operation, which conveniently happens to be very close to Joules in a gallon of gas (~120 million).

                In other words, for every single day, for every single square meter of an indoor operation, you need to use the equivalent amount of energy as is in a gallon of gas to grow things indoors. That’s ~4,000 gallons of gas (or the renewable equivalent) per day per acre, which is not that big of an operation.

                A quick google tells me that lettuce, probably the least energy intensive crop, can harvest about 10 tons per acre. According to the railroads, which might be a dubious source, a gallon of gas can move a ton of freight about 100 miles on a railroad. To move an entire acre’s worth of lettuce by train 3000 miles, approximately the entire width of the US, would use only 30 gallons of gas.

                Even if they’re exaggerating by a several orders of magnitude, there’s just no way for vertical farming to come out ahead on that.

                If you truck instead, a quick google tells me that a truck’s average fuel cost per mile is between 30 and 40 cents, and a truck can carry about 10 tons. In other words, moving our acre of lettuce takes about 1 gallon of gas per 10 miles. Even if we move that 3000 miles, we’re only using 300 gallons of gas (or the energy equivalent). Again compare that to using 4,000 gallons of gas per day on the vertical farms. Over a 2 month growing period, that comes out to 240,000 gallons of gas.

                In other words, trucking things all the way across the country uses 800x less energy than an indoor farm with 0 transportation costs would use to grow it.

                • kozy138@lemm.ee
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                  1 year ago

                  The thing is, you don’t need to reproduce the full power of the sun. All you need to produce, is the particular wavelengths of light which are absorbed best by the chlorophyll in the plants. And with modern LEDs, the power consumption is tiny.

                  With wind, solar, and geogermal energy production, one could theoretically power, and regulate the temp/humidity in the facility with a net 0 carbon emissions. Not a few hundred thousand gallons of gas…

        • bluGill@kbin.social
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          1 year ago

          I only know US rules, but I expect people worldwide to read this - your country will have different rules. In theory yes, but in practice no. US subsidies come in two forms: crop insurance and CRP. A long time ago there were a lot more programs in place, when people think of subsidies they are generally thinking of programs from the 1970s (which I know little about) that no longer exist.

          Crop insurance in theory covers indoor farms, except the only a small number of crops apply - corn, soybeans, and a few others I forget. It doesn’t make sense to farm these indoors as the value vs cost just isn’t there. Crop insurance means that they guarantee you will harvest exactly your 10 year average (the bad year counts against your ten year average for the next event!) and you can sell for some minimal price. Farmers insure their crops in the worst case they still lose money, but at least they have enough savings to ride out the year.

          CRP is where the government rents “bad” land from farmers so they plant it into grass. In really bad years the government will let you use that grass for hay, thus ensuring there is more food (well animal feed) in bad years. If the land is good quality crop land you are better off farming it, but if it is practically a swamp CRP ensures farmers don’t try to drain it. Obviously this doesn’t apply to indoor farms.

      • Spzi@lemm.ee
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        1 year ago

        Also what about other requirements, like water and fertilizer? Each tonne harvested has to be restored somehow.

        Either we get agro-industrial traffic in residential areas, or the thing isn’t next door to customers anyways.

        Are residential area water pipes fit for the task?

        I wouldn’t be surprised if the sweet spot for such operations is at the outskirts, where we started.