• @frezik@midwest.social
    link
    fedilink
    58 months ago

    There’s an inherent geometric problem with using solar for vertical farms. They use the volume of the space, which increases by a cube factor. Solar, however, increases according to surface area, which is a square factor.

    You thus quickly hit a limit where you can no longer power the lights for your vertical farm by solar panels you stick on the roof. You have to have either a field of solar panels elsewhere–which might have been used to grow food the old fashioned way–or you have to use something that scales differently. Wind also scales by surface area, so not that. Geothermal or nuclear are maybes.

    Possibility one way around this is tweaking the spectrum of lights that plants use. Taking full spectrum sun lighting, converting it to electricity, and then using LEDs to create full spectrum lighting isn’t going to work. However, plants primarily use only a narrow space of blue and red light as part of photosynthesis. This isn’t the full story, either, as plants do use the rest of the spectrum as signals for other biological processes.

    Now, do they need the rest of that spectrum all the time and at full power? Depends on the plant. It’s complicated, and we may end up customizing lighting for every crop.

    Even then, the square-cube problem will put limits on how big vertical farming facilities can get while being powered by solar and/or wind.

    • @Krauerking@lemy.lol
      link
      fedilink
      38 months ago

      Thank you. I had someone explain this to me before in this kind of directly data driven way but I studied astrophysics and macro-xenobiology so I am not the person to be explaining it back out.

      But yeah all that.

      It makes me wonder if you could build a vertical farm like a big greenhouse made of glass though and direct light from the sun through the building using reflectors without overheating and cooking the plants but, with green energy production you really get to a point where it’s the fields for growing crops previously are now covered in mined advanced electronics that need replacing and the farming structure itself which isn’t as scalable as just adding a field to your crop rotation.

    • @rdyoung@lemmy.world
      link
      fedilink
      18 months ago

      This isn’t the problem you two think it is. No one is talking about feeding an entire city from one skyscraper. But, you could feed an entire block from one or two levels of a skyscraper.

      I’m now going to block you two twits because I don’t have to time for this shit right now. Going out tonight to see Gladys Knight and I have to respond to someone helping me grow my business.

      • @frezik@midwest.social
        link
        fedilink
        68 months ago

        You know, if you feel the need to block people who are laying out arguments and being civil, then maybe you should rethink having Internet discussions altogether.

        • @Krauerking@lemy.lol
          link
          fedilink
          38 months ago

          They ignore people providing data and argue their opinions are worth more than facts, call people rude names and take the chance to brag about themselves every chance they can take.

          So they are the average American apparently and exactly the right level of self assured to be the desired group to sell anything too.
          They really shouldn’t be here but none of us are ever gonna get that through to them. They will be right whether or not the have to ignore everyone else to be so.

          • @frezik@midwest.social
            link
            fedilink
            38 months ago

            I’m American.

            Thing is, I actually am interested in this stuff and am working on setting some of the ideas up in my own backyard. I just have some idea of the limitations and what problems are yet to be solved.

            • @Krauerking@lemy.lol
              link
              fedilink
              58 months ago

              I know I know. We aren’t all like that but seriously they are all over this comment section being like this. Literally just above is one where someone says after providing a research study for emphasis "you aren’t entitled to assume a study is wrong just because of a gut feeling and this guy responded with:

              “Actually I am. That’s kinda how thinking for yourself works.”

              And I just can’t think of a more stereotypical, Self Assured American™ thing to say.

              I’m just trying to be practical and know that nothing is perfect, and have read up on some of the limitations of this to think it’s better than just ecologically friendly farming practices for widescape use.

              • @frezik@midwest.social
                link
                fedilink
                48 months ago

                I noticed that thread, too, and had a good pounding-my-head-against-the-wall session about it.

                This reminds me, too, of a thread I had some years ago on Reddit that was also about hydroponic farming. The other guy also had the idea that hydroponics would change everything, and would also shake off all the corporate control of farming. As if large scale hydroponics wouldn’t also become the new large scale corporate farms. Or that Monsanto would see the market shift and go “whoops, guess we’re irrelevant now”.

                I bring this up because I’ve noticed a trend of hydroponics advocates. They see the problems with our farming system, which is fair, but drink deep of the hydroponic flavor-aid and don’t understand the other problems of what they’re talking about. This tends to overlap with techno-fetishism. Grow plants in dirt? Like we did when we first learned to make fire? Move over, because I’ve got something that will make it way better without knowing how the current system works.

                • @Krauerking@lemy.lol
                  link
                  fedilink
                  28 months ago

                  Sorry to sorta necro this but I had a couple of his numbers floating in my head and I had to do the math.

                  He suggested that you could feed a city block with only 2 floors of a skyscraper which is already an insane ask but whatever.

                  But that means for a city like Philadelphia, you would need a total of around 16,000 buildings with 2 floors each dedicated to farming which widespreads your farmers. Or if you decide to dedicate each building to farming only you still need 322 skyscrapers each 100 floors high to feed the city.

                  Which means water pumps and infrastructure to support all that water for 322 buildings which is about the current number of high rises and skyscrapers in Philadelphia combined.

                  You need to convert your entire city to food production just to feed the city that is just existing to feed itself.

                  My God this really isn’t the win they think it is. Technology will certainly save us but man I don’t see it in the pie in the sky scifi answers but something boring like protein manipulation in yeast cultures.

                  • @frezik@midwest.social
                    link
                    fedilink
                    28 months ago

                    Not surprised at all. Beyond that, I suspect even two floors is already too many to effectively power the thing with solar on the roof of the same building. Even converting solar to electricity to a narrow spectrum of light at 100% efficiency for the entire thing wouldn’t get you there.