81 Comments

I think you’ve fallen for some of the deceptive marketing of vertical farming proponents.

The first problem with this article is that most of the comparisons are with open field “dirt” farming, so while vertical farming may use 20x less water than dirt-farming, it doesn’t use 20x less than greenhouses. And if you’ve ever been to a modern greenhouse, you’d can, and in many cases do, use many of the other techniques you mention - such as automated control of temperature and humidity, integrated pest management, massively reduced labor, and with all the other benefits - such as reducing runoff etc.


In particular your energy graph is massively deceptive since it doesn’t compare to Greenhouses.

To simplify it, high density cropping uses around 40% of the light incident on any one point, so lets say you stack 15 layers high as you do in the first photo - so for every meter of floor area you have 15 m2 of crop. You need light equivalent to 15*40% = 600% of the incident light, but you can’t get it to the plants since they are stacked, so you replace it with LEDs. Lets assume those LEDs are 100% efficient (they aren’t) but generated by solar panels + at 30% efficieny (though 16% is MUCH more likely) that would mean you’d need an area of solar panels of 15*40%/30% = 20m2 of solar per m2 of vertical farm. That of course is 1.3x as big as building a greenhouse - i.e. replace every 20m2 of solar panels (glass on frames) with 15m2 of greenhouse (glass on frames) and you’ll get better results financially and from the sustainability perspective. And at the more realistic 16% efficiency for the solar+batteries+LEDS its 2.5x as much land.

This is why so many vertical farms are in trouble - it doesn’t live up to its promises, either from a business or sustainability perspective when compared to greenhouses. This of course is also why Vertical farm proponents compare themselves to dirt farming rather than state of the art greenhouses - a deception that has unfortunately propogated into this article

Hydroponic Vertical farms have all the nutrient density issues of hydroponic greenhouses, the better (e.g. dutch moving gully) systems use dirt instead of hydroponics, but this is much harder to do that in a vertical environment.

Land in the middle of cities is very valuable, but you can put greenhouses in the urban fringe with many of the transport benefits, even more so with something like Bluesmartfarms.com’s integrated fish/plant systems.

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Very good points indeed, Mitra. Thanks for sharing! I’m addressing many of these topics in the premium article this week. LMK if it still doesn’t make enough sense for you!

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Here is a breakdown of energy costs: https://decodingtech.substack.com/p/agricultural-revolution

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In case you will cover calorie crops like grain as well, can you please also give consideration to energy efficiency price floors? Such as this argument: https://x.com/TamarHaspel/status/1292895062716821506

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Thanks for these links! Will process for the next time I write on this

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Thanks - I'm not a premium subscriber so won't see it. I really think this article needs correcting, its far from up to your usual factual standard, by a very very long way. Its like saying self-drive cars are good because they are better than horse and cart.

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The gist is that it's a continuum from dirt farming to vertical farming, where greenhouses are in the middle. Like for example if you're in cold climate, the loss of energy from heating might be very high, and insulating the greenhouse might be worth it. But insulation is cheaper as a building, at which point it might be more efficient to simply build a building and use artificial lighting instead of sunlight. And at that point you might as well stack your vegetables to better amortize that CAPEX.

Plenty of examples like that.

Also on your calculation I'm not sure you accounted for the fact that LEDs are much more efficient because they only emit purple light, or is that your 40%?

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A lot of "might" here, as far as I'm aware these advantages (over Greenhouses) aren't actually there with vertical when you do the numbers - both vertical and modern greenhouses need very active climate control to keep temperature/humidity etc in the optimum zone. In particular the inefficiency of going from solar to electricity and back to light (even at specific wavelengths) is dramatically worse than just using the solar directly.

i.e. is not a spectrum from dirt to greenhouse to vertical; its a a spectrum from dirt to low-tech greenhouse to high-tech greenhouse to aquaponics, with the verticals being more expensive, and less sustainable than the greenhouses - hence the financial difficulties many of them are hitting.

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Interesting and very relevant choice of topic!

Thoughts:

1) OOM improvements in food product to biomass ratio possible. Most of current agricultural production is not food, but biomass waste. End state might be only the desired fruit or leaves being left, nourished by artificially generated plant juice.

2) Labour costs will drop with scaling+usual efficiency improvements. Then, remote controlled worker robots steered by workers from low cost countries will reduce labour costs in high income countries. Finally, AI controlled robots will eliminate most of it.

3) As always, cheap&clean energy is the base of everything. Solar&Nuclear for the win.

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1. Very good point!

2. Agreed!

3. Agreed!

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Re artificial plant juice, check out acetate feeding. It is not quite the same, but offers significant energy efficiency improvements:

https://www.cell.com/joule/fulltext/S2542-4351(24)00429-X#:~:text=on%20photosynthesis%2C%20germinating-,seeds,-depend%20on%20heterotrophic

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One issue you don't mention: plummeting nutrient levels; in soil and food.

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Fantastic article. My son in law was an early investor in vertical farming in of all places, Florida. The company, I believe, is pre IPO, but has been growing like crazy. Your article breaks it down better than anything I have read. It's yet another example of yourvout of the box thinking, and most importantly, educating your readers in what should be a major sea change in agriculture.

Maybe I will listen to my son in law next time!

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Many of these companies took too much money from investors and had to scale back. The unit economics are frequently bad. But at some point they will become good enough! Maybe your son in law’s company is one of the lucky ones.

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Your son in law likes to light money on fire or has no interest in diligence.

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Excellent article, thank you.

Although I am very excited about the prospect of vertical farms, my immediate thought is of mycorrhizal networks. How are the services (pest control, nutrient supply, root growth support etc) replaced in a vertical farm? Furthermore, is the produce from vertical farms comparable to current crops in terms of nutritional value, or to the far superior crops from the time prior to the post Green Revolution destruction of soils? I also wonder at the lost benefit, or in fact serious detriment, to our own body’s (particularly the gut’s) biome to eating crops grown in a sterile environment.

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Very good Qs! The short answer is that this is a known problem that these companies explore. One of them uses shredded insect exoskeletons as a sign of aggression, and that boosts the generation of some elements needed for defense and that turn out to be demanded for taste and nutrients in humans.

What this means is that I assume this is a current problem that I expect to be solved

Over the coming decades.

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As I understand it, fungal and bacterial friends are needed by plants mainly to rise the availability of nutrients, water, and information; if these are being sufficiently cared for by humans, symbionts are not necessary. Indeed, even outdoors, when plants grow at high nutrient & sufficient water conditions they emit less mycorrhiza-attracting compounds and form less connections with fungi. The fungi are not totally cheap, they have to be fed with sugar.

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All very well, but at present investing in vertical farming is a mug's game: Witness the bankruptcy of AppHarvest, Kaletra, Infarm, and many others.

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True indeed!

Industries might succeed while most of its individual companies suffer.

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Very interesting article. I share your hope that this technology takes off in the coming century, but I am more skeptical than you. Food production is essential to human progress.

The global food base is dominated by rice, wheat, corn, soy and potatoes. Until vertical farming becomes viable in those crops, I do not see it being more than a niche production technique used for fruits and vegetables.

I am also skeptical that there will be towering skyscrapers growing food. Construction costs per square foot increase as the building gets taller, so my guess that vertical farming will look more like warehouses than skyscrapers. That will still save a huge amount of farm acreage, though.

My guess is that robotics to dramatically lower labor costs will be key.

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People love to write “analysis” about vertical farming when they first discover the concept as if they themselves are the first to discover the concept. It’s a trash idea that tries to transform macro vagaries into a panacea business model. It has zero merit, empirically and analytically.

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You could have said this about solar panels 20 years ago and sound clever, and still be wrong!

The fact that it’s not viable today doesn’t mean it won’t be viable tomorrow. The question is what’s the path to get there, and that’s what I’ll cover in the paid article this week.

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Terrific article covering a fascinating issue. I live in a country smaller than West Virginia with a large amount of non-arable land due to water reclamation. And yet, we are the world’s second leading exporter of produce behind the US. The reason is embedded in the technological solutions you mention in your piece.

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Ah I didn’t know! Will look into it!

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One more point about the Promise of Vertical Farming.

Did you folks know that a 1st effort internal combustion engine was invented in 1794? With various improvement thru the 1800s ? Until Otto developed the 4 stroke cycle engine in 1876?

There were only about 2,500 cars in the world 15 years later

By 1900 - only 8,000 cars - almost a quarter century after the combusion engine.

Some things take time. The physics of the LED were done a half century before an LED made light.

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It takes some perspective to understand these long term trends. Thanks for sharing this very relevant comparable. I didn’t know!

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Monoculture issues with viral diseases a potential problem. Maybe Musk needs to invest as he will need this on Mars

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Yes, but you don't need to do monoculture in vertical farms, and pests are much better controlled!

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Very very very nice indeed!

I'm 57 in 2024 and I've always dreamt a world where there are only vertical farms, building with plants, less street and more green, 80% less vehicles (possible with the advent of self driving autonomous cars that will sign the end of 1 car per person)...

It looks a bright future if we will do the right things, in time! But it will happen anyway.

Up to us make it happen sooner.

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The embedded resource footprint of the infrastructure for vertical farms is huge and often not included in assessments of their efficiency or impact. As someone who has tried to start a vertical farming company I learned the hard way about many of the challenges. The point about cost per height is also relevant. As is the issue of the narrow crop range the systems can grow. I look forward to the paid article exploring the challenges in more depth. What % of global calories come from crops (or animals fed on them) that will almost certainly never be grown vertically - grains? And what % of resource footprint does that represent? Growing that type of produce more sustainably and efficiently would seem a better place to focus one’s energies.

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It's coming tomorrow. I look forward to your take on it!

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Fascinating article, I'd like to see vertical farming expand by orders of magnitude.

Biggest problem I see is whether it's economical to grow a wide variety of crops, particularly grains. Right now, it's mostly greens being grown, with a few other things like tomatoes and strawberries.

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Agreed!

Correct.

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YES! Vertical farming is a good solution. My son and I have talked about this. This absolutely solves much of our agricultural products except trees that bare fruit and nuts.

Another huge issue is animals bred for consumption. If land could be used more effectively for that and the waste treatment resolved that would help as well. Regenerative farming.

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Seriously, I don’t get the fascination. Land is cheap and plentiful, greenhouses provide tightly controlled environment if needed without all the hassle of vertical farming. Mass production of plant based food is solved problem from technology point. Existing problems are linked with regulations (EU for example artificially keeps much bigger workforce in agriculture than needed due policies, plenty of similar examples around the world) and distribution. Water is sometimes scarce, but current technology makes possible for getting in challenging areas, assuming well-functioning political organizations.

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All these things are true. And yet they don’t address the article I believe?

Water is indeed scarce, and that matters. In some places, land is expensive.

Greenhouses are indeed a big deal

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The problem is that it is about “some places”, transportation is cheap these days - there is no need to grow food in specific places.

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As long as that transportation is available. Add wars to the mix and you get a very convincing reason to decouple farming from specific place on Earth.

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But that is the crucial contradiction: without political stability vertical farming (capital intensive) is not feasible, with political stability: there are simpler ways, obviously we may find some specific niche here and there: but it is not going to be hugely impactful in universal terms.

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This is spot on Tomas. We have been vertical farming since 2015 for our own consumption and for friends, family and others who want "clean greens". We started with a kit greenhouse from Home Depot and vertical towers from ZipGrow,

much instruction from Upstart University on-line, basic knowledge of chemistry and voila. Anyone can do this with a small investment and motivation to keep learning. Large scale is a must for our future. But back yard gardening using hydroponics will help too. And it produces the most beautiful greens and veggies.

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I was thinking of doing a proof of concept at home for my children. What would you recommend?

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It’s not a proof of concept if other people have already done it. It’s just a bunch of junk in the garage that will prove nothing other than it’s a terrible hobby that everyone eventually abandons. But that’s already a well known fact also not in need of being demonstrated again.

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The easiest way but more expensive is to purchase a hydroponic tower kit which has everything you need. There are several to choose from on-line. We started with ZipGrow for our infrastructure. They have instructional videos online. The most difficult aspect is understanding plant chemistry to ensure necessary nutrients are reaching the plant.

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