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Comment by LargoLasskhyfv | Hacker News Reader

Why not? Build it with a glass front? Put it on a turn-table, and have it follow the sun!1!!

How is that different from a glass house or normal agriculture? A normal piece of farmland or glass house captures all sunlight falling on its surface for the produce that grows on the same surface, ratio 1:1. If you were to use sunlight falling on the vertical farm with 5 floors, it would have to divide the sunlight over more surface, ratio 1:5, so there is less sunlight per surface.

Solar panels + lights together are a system for redirecting energy, and the efficiency “loss” is inconsequential. You can simply cover an adjacent area 10x the size to provide the extra sunlight.

But then why not cover the adjacent area with crops and sod the vertical farm, solar panels, grow lamps, wiring, and all the costs, construction time, maintenance work, etc. and just have a farm?

Instead of an adjacent area, the panels could be in an arid desert. Meanwhile, the vertical farm is in a population center and using less water

That is equivalent to saying "vertical farming is cost-effective where energy is free and land is scarce and expensive".

Oddly enough, precisely the opposite circumstance describes most farming.

Because good land itself might just be more expensive to purchase and maintain than all of those systems in a highly dense footprint?

Why not just keep growing it in the soil? We aren't on Mars.

There are, broadly speaking, two groups of people who are very interested in vertical farming.

1) People who wanna grow mind altering plants and fungi.

2) People who are worried about destabilized food supply chains and would rather have $10 lettuce than no lettuce.

Both groups have priorities that come before riding the razor's edge of economic efficiency.

3) People interested in self-sustaining artificial islands/seasteading where space+water efficiency is paramount.

And people who want to eat local foods

Local foods are necessarily more ripe and fresher than remotely grown foods. There are more reasons than supporting your neighbors or stable food chains - quality is almost universally higher at a farmers market than at a big box store. That’s not because local farmers are superior, it’s because they harvest closer to optimal ripeness and sell it fast before it spoils. Food grown on the other side of the planet and shipped in storage containers is necessarily harvested very early and is non optimally ripened, or never ripens.

You're probably in group 2.

Why do you support local farmers? Like on a deep level? Deeper than "well they're my neighbors" Why do you support your neighbor over some guy in Nebraska? Probably because his culture an interests align with yours whereas the same is not necessarily true about the guy thousands of miles away and all the parties between you and him. You'd rather be slightly less dependent on the long supply chain than the short one.

Where true, I think that counts as "missing the point".

Local foods are, as I understand it, supposed to be some combination of more eco-friendly and supporting local farmers.

Growing a potato in your kitchen cupboard using hydroponics and PV+LED is very local, but you'd have to grow a lot of them before you saved more on transport and processing emissions than created by the equipment; and you certainly aren't helping local farmers by doing it yourself.

Local is purely about quality for me. I can get food that’s riper fresher and tastier if it doesn’t have to travel.

Because certain plants don’t transit well to urban areas and you can reduce waste and expense by growing them adjacent or in urban areas, providing fresher food for the same cost. That’s why they tend to grow delicate leafy greens.

Even in such circumstances, lower-intensity ag methods such as greenhouse farming (enclosures to accommodate for inclement weather), but still relying on incident sunlight, are far more resource-effective. The land-use requirements are still large enough that the technologically- and energy-intensive vertical farming methods simply won't compete.

I'd also like to know what these magical nontransportable crops you have in mind are.

Hmm, I had issues with the verticality, but hydroponics can save a lot of water (regular greenhouses too, by capturing evaporated water; you can also use pots). Indoor heating, temperature control, and protection from hail also mean year-round production, or at least protection against random weather events. Greenhouses can achieve most of these already, with more efficiency gains if water cannot escape underground.

Verticality (including regular shelves on a single floor) is good for density (may be cheaper to build), but has energy density issues for some crops.

Even on planet Earth many places are not arable:

https://www.mapsofworld.com/thematic-maps/arable-land-map.ht...

True but you're better of combating waste, land degradation, land access/commoditization, etc than inventing some overall lack of arable land. Bigger actual benefits tend to stem from the controlled environment. Sure there are places where these things make sense if you want to limit transport (Water retention in the arab peninsula or the like) but honestly we see it hyped more often in places where it does not.

It's the same nonsensical reasoning behind putting solar panels in places where they don't make sense. I remember france putting money in a solar panel road that was both ridiculously overpriced and ridiculously ineffective for reasons completely predictable. Of course places where solar panels made sense were in essence still barely utilised. Someone just made a lot of money off of the invented scarcity.

I agree with the notion that technology should be used appropriately, but the issue seems to be corruption and that people buy into hypes and misallocate technology, not that the technology itself is useless. I am sure that some corrupt officials manage to overpay for sand in Sahara.

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