I’m asking mostly because I want to include them in some solarpunk art I’m planning, but I can see building one at some point - it lines up well with my interests in making things and getting more self-sufficient - I like the idea of being able to cook without fuel.

But if I’m going to show them, I want to make sure I’m depicting them accurately and doing my world building decently. I’m hoping someone here has some experience with them,

I have a few scenes in mind where I’d like to include some form of solar cooker or smelter:

  • A work crew outside, possibly people salvaging cars, fixing a road or track. They’d probably be using a small, foldable parabolic cooker to make tea or heat soup?
  • A cookout with a bunch of different people making different things
  • An offgrid homestead (possibly combined with above)
  • A scrapyard which is smelting for large projects (it sounds like some very large reflector projects can get this hot but I’m not clear on how to turn that into molten metal yet)
  • Small workshops using some kind of reflector or concentration lens to smelt for sand casting.
  • Maybe just a kitchen.

My questions:

  • What’s the best design for different jobs? It sounds like the functionality of these cookers varies pretty heavily by design, so a scene of a cookout would probably have different ones doing different jobs - maybe one or two bigger ones built in to the yard or house, and portable ones people brought? A small workshop can probably build a good enough lens-based solar concentrator or reflector (not sure which would work best from what I’ve read yet) but the junkyard would probably need the giant reflector setup, right?

  • How do you picture changes to cooking infrastructure? At least around here, kitchens are kind of built around gas or electric stoves, and woodstoves before them. A solar cooker would need to be close enough to be practical (I’d currently be carrying whatever I’m working on down several flights of stairs to reach good sunlight) Would we see more kitchens with attached decks? Built at least partially in glass sunrooms? Built on the roof or with some kind of rig that lifts up through the roof? Or just more cooking outdoors? Maybe these would be closer to a grill, where taking your food outside is part of it, and how often you use it depends on household

  • What safety mechanisms can I show? It sounds like depending on the design, it wouldn’t be hard to accidentally point the light at something flammable (even if it’s not at the ideal focal length could it still ignite?) Is there a risk of eye injury, sunburn, or anything else I should add precautions for?

  • It sounds like these take longer, and are perhaps closer to a crockpot, where you just leave them cooking for a long while. Worldbuilding-wise, how different would the cooking experience be, and are there any interesting impacts on a solarpunk society (which might already be lived in at a different pace, or placing emphasis on different things).

Thank you very much for any input!

  • schmorpEnglish
    5·
    10 months ago

    Look at the infos about Tamera solar kitchen, they might have a few videos online, for an example of a working solar and biogas kitchen for that can feed 50 people. They use a giant parabolic concentrator in front of the open kitchen building and the heat arrives in the stove inside (so you don’t have to cook outdoors). I guess you probably don’t get an instant burn if you were to put your hand in there. There are also associations in India that use big solar cooking systems for large kitchens, don’t know names though.

    There’s also smaller cookers (still big) where food cooks inside a 25cm diameter tube. Good for a family dinner - meat, potatoes, cake can all go in in one go. I managed to get one of these to about 85°C - so food tends to cook slower, people have to account for that. I would say you could put your lunch cooking before you leave for work and return to your food cooked. It won’t burn as easily, an hour more or less doesn’t hurt. And it tastes more delicious.

    There are really small models - some done in concrete, some just cardboard boxes. But food would take even longer in these, not sure about the details.

  • poVoqMA
    2·
    10 months ago

    Small work-crew heating up something are probably better served by a small wood burning rocket stove.

    But I could easily imagine some sort of foldable parabolic solar cooker on a bicycle trailer for a mobile kitchen to cook a larger lunch or so.

    A metal furnace would need a larger array of tracking mirrors similar to those large solar thermal power plants with central towers. Just putting a furnance on a tower would be likely difficult, so I imaging it would utilize natural geography and place the furnance on a steep hillside or so.

    • JacobCoffinWritesOP
      3·
      10 months ago

      I like that! I can definitely see doing a bike trailer / food wagon for that scene.

      I really dig the idea of using the landscape for the furnace setup, and it looks like there’s at least some precedent; wikipedia mentioned a proposed concept using pit mines

      though it’ll take me a bit to figure out how to lay out the scene (and to hopefully make it realistic)

      edit: in fact, something like this might end up being a good reference: https://en.wikipedia.org/wiki/Odeillo_solar_furnace

      • poVoqMA
        1·
        10 months ago

        Maybe you could also conceptualize a solar powered rotary kiln for cement making?

        • JacobCoffinWritesOP
          2·
          10 months ago

          rotary kiln for cement making

          Interesting! I’m just learning about these for the first time, but it seems like it’s about getting the rawmix up to temp so it becomes clinker, and the different designs are mostly about how much throughput you get, with rotary kilns being the most efficient. It’s definitely an area with room for a greener design, though I don’t know enough about concrete manufacturing or solar furnaces yet to guess at what would work best. I see cement is also cooked in shaft kilns and lime kilns, at least in the past, I wonder which would be the easiest to adapt to being heated by a constant searing blast of sunlight (it looks like the current designs spew fire directly into the kiln?). Concrete is a huge part of our current world, so that throughput is obviously pretty important, but I think a solarpunk society would accept a tradeoff of less or more expensive concrete with fewer externalities. Also I get to cheat a little with this setting by making it a bit postapoclyptic, meaning a lower demand on resources to support the society (though with rebuilding, concrete demand might be higher than I expect). The point being, I’d be happy to depict a reconsidered manufacturing system, though I might need some help matching a workable kiln design to a solar furnace design.

          • poVoqMA
            1·
            10 months ago

            Not sure about how that would work exactly either, but cement making is a very energy intensive process (mostly heat though) and even a Solarpunk society will not get around having some production of it for foundations and the like. I also think rebar can be more easily recycled, while cement basically needs to be burned freshly from limestone etc.

            • JacobCoffinWritesOP
              3·
              10 months ago

              Yeah, the more I think about it, the more I want to try some solarpunk industry scenes. As far as I’ve seen, there’s very little of that in existing solarpunk art, lots of pastoral scenes, lots of urban and suburban farming, but all the tools and building supplies have to come from somewhere, and this is solarpunk, not solarneolibralism after all - we can’t just offload industries and the damage they cause to poorer places and call it good. If a society is going to be solarpunk, it needs to be equally distributed, and can’t handwave things like materials production. I think it even fits the postcard theme; after all, a solarpunk society would take some pride in doing these things better (even if they’re not perfect yet). I’m gonna start with steel I think, it’s slightly more familiar ground, but I’ll read up on cement and try to work out a solar kiln design.

  • heeplr@feddit.de
    2·
    10 months ago

    it’s hard. It gets easier if you only need to operate in hot, desert-like weather conditions. Otherwise: Size is your friend.

    You need to focus light on a small spot (where your pot is usually). Doing that optimally needs careful and precise manufacturing. Portability/deployability doesn’t make it easier.

    You can plug into RF expertise, tho as light is similar to radio and parabolic antennae are pretty well researched.

    I’d do some math on the minimum size, get a nice parabolic antenna, coat it to mirror, polish, calibrate, done.

    • JacobCoffinWritesOP
      2·
      10 months ago

      Thanks! Have you used/made one? I can definitely focus on parabolic designs, I think they’re a bit more visually clear anyways. I like the idea of reusing/recoating existing antennas (it fits the kind of postapoclyptic vibe I’ve been including so far)

      • heeplr@feddit.de
        1·
        10 months ago

        i never made one but used one a few times. Their performance get drastically impacted if they just get a little out of shape/bent/dented.

        Sounds like a fun project. Make sure to post pictures!

        • JacobCoffinWritesOP
          1·
          10 months ago

          That makes sense and also sounds very frustrating. What type did you use? Do you have any quality of life advice or aspects of use you’d like to see shown?

          I could definitely see portable ones getting banged around. I wonder if I should show some kind of way to protect biger fixed installations from strong winds, or other ways they could get messed up.

          I’ll definitely post the pictures - I put them up on the art community here, along with some other sites like pixelfed and Mastodon, and any decent sized Lemmy community it I think the pic fits their theme.

          • heeplr@feddit.de
            2·
            10 months ago

            I used a modular parabolic one, about 1m diameter. Assembly took ~20 minutes (without electrical tools and lots of experience) and it didn’t work well with even slight clouds. In glaring sunlight it worked fine, like a gas cooker.

            I still like to see one that is cheap, user friendly and ultra efficient. I think some smart sliding system, foam/buffers to prevent damage and parts rubbing, or even high-end materials (mylar-like foil that makes the reflecting membrane).

            Maybe check google scholar as there probably was quite some research on the topic.