[SimianLogic2]

This article is more about indoor farming than vertical farming (is it even vertical if there's only one row?). I grow lettuce indoors. It serves as a nice houseplant and fresh source of salad greens for lunch. It's fairly new, so the cost isn't that much different than just buying lettuce. Once I start building my own "pods" instead of buying the brand-name pods, though, I expect it'll be a bit cheaper than buying 4 bags of lettuce every week (although it doesn't produce enough to fully replace buying greens).

Mine produced ~4 bags over 6 weeks for an energy cost of ~$5 and a negligible amount of water. I think I can get the per-plant cost down to ~$0.50 once I start using my own seeds, so around $10 over 6 weeks to replace 4 bags of salad at around $3 each... a grand savings of $2. We're moving around 4 bags of greens a week between 2 adults, so I'd need to 6x that to replace all the greens we're eating, which gets the savings up to ~$2/week.

The cost savings is negligible -- I do it because it's neat and I like having a houseplant I can eat. It's also MUCH easier for a residential system to offset its energy usage than a commercial setup (I have way more square footage on my roof than I would ever "grow" inside my house).

The calorie argument is more compelling, but how many thousands of years did it take for people to get wheat so calorically dense? I think it's going to take time to develop nutrient-rich crops specifically tailored for indoor farming.

[the_gastropod]

I understood the point to be more about the energy inputs. The gist of it is: plants are more efficient at capturing energy from the sun directly than indirectly via solar panels -> light bulbs -> plants (which seems obvious, when you state it that way).

The only thing that makes vertical farming make any financial sense, today, is the access to cheap (subsidized) fossil fuels.

[kibwen]

> plants are more efficient at capturing energy from the sun than solar panels -> light bulbs -> plants are

This is a counterintuitive misconception that I mention elsewhere in this thread. Plants aren't optimized for raw sunlight utilization, because that's not the bottleneck for growth or survival. Plants deliberately reflect away 90% of the sun's energy (https://en.wikipedia.org/wiki/Photosynthetic_efficiency) because other factors are more important: https://www.quantamagazine.org/why-are-plants-green-to-reduc...

[falcolas]

> deliberately reflect away 90% of the sun's energy

They'll have that same efficiency with artificial lighting too… At least until our grow lights stop emitting light in the green spectrum (not something I expect to see anytime soon).

[kibwen]

Grow lights are quite good at only emitting light in certain parts of the spectrum, and have been for some time now.

[falcolas]

Just looking at some spectrum charts for grow lights... They certainly vary, but not in any uniform fashion.

There is an exception to this: there is a standard LED graph which shows up quite frequently, identified by it's peeks in the deep reds, yellow, and dark blue, with a marked trough at cyan.

[bee_rider]

The cost of transporting the conventionally grown plants would have to be accounted for as well, but I'd be pretty surprised if that got anywhere near tipping the scale over to vertical farming.

[Ekaros]

I wonder if that could be solved more easily. Build sufficient rail network and hydrogen/electric/other zero-carbon trucks to move produce from production to there and then train it in. And this is really a sector we could fully automated almost already.

[trickstra]

Switch hydrogen for methane and produce that methane in a bioreactor from the food scraps. These technologies are already here, no need to wait for a future hydrogen car.

[bee_rider]

Also, building a zero-carbon transport system would be generally useful for transporting things other lettuce. And that's probably like 80% of the way toward a zero-carbon transit system. I think you have a good point.

[jseliger]

Have you written comprehensively about the system you've set up and how it works? I've thought about a Zipgrow system or similar: https://shop.zipgrow.com/products/small?variant=316809164227..., but, as you can see, it's fairly costly to set up. I don't think it'll be cheaper than the grocery store, but it also seems fun and like the final product may taste better.

[SimianLogic2]

I'm just using a 9-plant Aerogarden Bounty right now (think it was ~$175 on Black Friday). My wife says I can upgrade to an indoor Tower Garden or Lettucegrow if I do 3-4 cycles on this thing without getting bored.

I also built six 4ftx4ft raised (dirt) beds in our back yard a few years back. I plant fairly densely (usually using 1x1 squares for most things, 2x2 for tomatoes) and I'm thinking about trying one of the tower gardens as a replacement for a single 4x4 bed this growing season. It's been a minute since I ran the numbers, but I think you can plant 20-25 plants on one tower vs maybe 4-16 in a single bed and theoretically not have to weed/water as much (but then you get pump maintenance/ph balance/feeding/cleaning instead).

[User7894]

Look at BA Kratky. My variant consists of 10Gal mixing tubs (Lowes $6) a bit of blue dow foam board, toothpicks, and rapid rooter growplugs Barina grow lights. Masterblend, CaCO3, and Epsom salt. Six trays (one per week. Pest pressure and growing season makes leafy greens not practical.

[SimianLogic2]

I think I'm following your build. It seems like Kratky requires a lot more space up-front than an aeroponic system that you refill over time, but it's good to know that I can get even lazier if I clean out some space in the garage.

[Pfhreak]

I haven't written about mine, but I built one using an aquarium pump, a couple of food grade bus tubs (the kind wait staff use to clear restaurant tables), a couple LED panels, and some basic plastic cups. I grow basil, lettuce, bok choy, cilantro, and it doubles as a good setup for getting vegetable starts going in early spring. It was probably a couple hundred bucks to get going, but it's low maintenance and I get produce and herbs on demand.

[Guest19023892]

If you're looking for something more cost effective, you might want to consider building your own with some LED strips and a driver. You can get higher quality components and a lot more power than kits typically sold by companies.

I'm building a 2ftx2ft indoor herb garden for my apartment right now. I found the LEDgardener to be a good resource and forum for getting started.

https://ledgardener.com

[JoeAltmaier]

Is that including amortizing the space it uses in the house? That's not really free.

[SimianLogic2]

https://twitter.com/SimianLogic/status/1361768051276992514

Kind of free? There was nothing in that space before.