Imagine if "last mile" was an elevator down to the first floor which was a fresh produce store. Someone could build these kind of structures on top of subway stops. There could then have elevators / stairs down into the subway so commuters could easily buy food on their way home.
Also, it's not possible to ship some produce and maintain quality. Think sweet corn which (also avocados), yes, is still sweet when you get it in a grocery story but is far from as sweet when picked. There are also studies about loss of some nutrition just days after being harvested: https://fruitandvegetable.ucdavis.edu/files/197179.pdf
And, you can make the case from other sides too. There's some initial interest in looking at how climate change, and rising CO2 levels, are affecting plant growth. Due to higher CO2 it seems like some plants are growing larger but less nutrient dense: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9003137/
There are other factors which could make something like this make sense (if you solved some major tech challenges, got the land and materials for free, and only focus on social / ecological impact). For example, some fun reading can be found around the CO2 impact of fertilizer farming and tilling practices which could be removed by growing nitrogen fixing crops like beans/beats or growing in aquaponics systems so you can also sell fish and make algea.
> Pretty sure almost anything else is more profitable on a sqft basis - retail, housing, dining, entertainment, etc.
Yes, I fully agree. From my comment: "something like this make sense if [...] got the land and materials for free"
> Urban utility rates also tend to be much higher than a bit further ou
If you could centrally plan this kind of project and had complete freedom to do anything you wanted you could:
1. Use light tubes to funnel sunlight into the building for the plants. You could also pretty cheaply collect more light than the sqft-age of the roof by putting reflectors on multiple roofs to reflect light towards a central point on your farm building: https://en.wikipedia.org/wiki/Crescent_Dunes_Solar_Energy_Pr....
2. You can make the entire building a greenhouse. NYC loves steel, glass, and concrete so you could probably make the entire envelope of the structure glass. Many buildings already do this: https://www.youtube.com/watch?v=kdy-bOTYlDs. This would let even more light in.
3. You could use this building as part of your waste treatment process. Human waste has a lot of nutrients needed for plant growth (nitrogen, phosphorus, etc). Rather than ship fertilizer, mined and processed across the globe, we could just extract most plant nutrients from waste. We're (the USA) currently not entirely managing this side responsibly: https://newsroom.ucla.edu/releases/treated-sewage-algae-bloo...
4. We could use far less water which, in climates which do most of our growing, would be pretty important. Since the building would essentially be a greenhouse you would retain a lot more moisture.
There are a lot of synergies where if we had control over the growing environment we could improve things. For example: we could collect light in light tubes, use crystals to split out only the light segments which the plants need, and use the remaining light segments for solar energy (panels, desalination, dehydration of products, etc). There are endless mini optimizations that we can't do right now.
Obviously, though, this is entirely hypothetical because the construction costs are not currently yet outweighed by the existing farming industry production pipeline. Once more externalities are accounted for that may change things (ex: we lose the ability to mine fertalizer due to war or supply). Then moving food production closer to consumers might make sense.
It always puzzpes me that people with zero idea how dirt cheap shipping is per unit believe drones, or moving production closer to consumers, woupd ever work from a price/cost point of view... And since the last mile is the most difficult one, supermarkets are pretty good in outspurcing that to customers.
For now. Who is going to be the first company to pull it off though? I'd definitely subscribe to that - would love fresh produce parcels dropped off on my front steps or backyard by drone delivery. This has already been done with medical supplies before which is super cool.
I really don't think it's feasible without some kind of AGI (or human) on the controls. There are so many environmental, technical, societal and regulatory issues to tackle. They make a lot of noise (although some are much quieter now), people could very easily jam their communication signals (or just shoot at them), birds, hardware failures, ... I worked on last-mile delivery project at a drone startup, we could do cool demos that impressed shareholders, but I could never see that working in the wild, people would get hurt.
Also, once you solve the last-mile problem, a new one arises: the last-foot problem...
