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Comment by mjhay | Hacker News Reader

Vertical farming is just a concept that makes no sense. It requires a lot of electricity in practice because there is not enough incident sun, building costs, and then there's the soil. Why not just build a greenhouse, or just a regular farm?

I think it's telling that everyone interested in vertical farming is from the tech industry, not agriculture.

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The article uses the term "Controlled Environment Agriculture" (CEA), which seems like a better descriptor than vertical farming, which is pretty narrow in scope and a bit solarpunk in vision. The nice thing about the term Controlled Environment Agriculture is that it can cover a wide spectrum of enhanced farming techniques, including a plain old greenhouse. Then it becomes a question of which type of CEA is most appropriate for an area. Even the most crowded cities tend to have areas of much lower density nearby that make the high-rise farm idea not a good use of resources. But boring old warehouse space used to create a controlled or semi-controlled growing environment might work in some cases, especially for higher value, fussy plants. Probably will never make sense for things like iceberg lettuce.

It's funny you brought up lettuce because for my thinking, head lettuce and salad greens are likely the only thing vertical farming would make sense for.

The plants themselves are compact and mostly green bags of water. The big costs are cleaning, processing, transport, and refrigeratoration. There is almost no manual labor involved.The life cycle is extremely short. The demand is extremely high.

Lettuce might be the only vegetable that vertical farming makes sense for, but it would need to be able to cover the cost of expensive light-industrial space very close to market.

Ultimately plants are solar panels and even in vertical farming it's space you are paying for. Even if you can plant 10 layers deep, youre dealing with maybe having to pay >10x per SQ ft for space in a location close enough to be relevant.

I agree with the sentiment on lettuce. It should effectively be grown in-store. I'd say that a few other leafy greens fit the bill -- cilantro, basil, spinach, kale. There was a startup operating in my area doing just that, that recently went under. They were focused on higher-price herbs, and I think a major mistake in their model was in using valuable retail space for the hydroponic setups. A couple of stacked containers in the parking lot should be much cheaper, and produce enough volume to be competitive on lower $/kg crops like lettuce and spinach.

Chlorophyll has very narrow bands of absorption. Collecting wide spectrum insolation with solar panels gives you plenty of energy to emit narrow-band light from LEDs, even with efficiency losses. In fact, plants do fine in red light.

Hydroponics is a well-understood technique - retail kits are available for home ganja growers. Soil is not an input. You would be nuts to grow in soil.

Greenhouses are great, think of vertical farming as gen2 of greenhouses.

Don't mistake VF as a solution for land-extensive staple crops. It won't grow significant quantity of cereal any time soon. What it does promise is high-value crops like salad, herbs, tomatoes, strawberries. These crops benefit from short food miles and are labour-intensive to harvest. You can cut costs by growing them closer to cities, in beds that you can bring to a comfortable height for picking (or pick by robot).

Some of the big costs are: labour, fertiliser, and transport to market. The latter two are tied to energy costs, and the former is expensive in high-CoL places where you want to sell the goods. Hydroponics makes much more efficient use of fertiliser and water, and may reduce labour costs. Vertical farming enables you to operate close to cities where land coats are high.

Are you qualified to say who is and who isn't interested in vertical farming? Have you been reading Farmer's Weekly or just HN? But for the sake of argument: existing ag interests are the incumbent and tech is a sector known for disruptors. VF is tech-heavy. It wasn't farmers who invented tractors, it was engineers and entrepreneurs.

But this is an interesting point, and the whole thing may turn out to be delusional techbro vainglory. I think that's a stretch in a world where energy cost has tripled in a decade and desertification is an observable reality. I wouldn't look for farmers in the startup, I'd look for biologists and grocers. Farmers are the customers, and the ones losing their livelihoods are good sales prospects.

do you have any references for the 'speeds and feeds' kinds of basics here? I'm playing in this space and having a lot of fun. but sometimes when I look at my plastic tubs and custom water-cooled led fixtures - I often think that its a fundamentally stupid idea - a great way to grow a $30 tomato.

edit: I looked up some very high level and recent bloggy stuff. apparently a traditional greenhouse uses 5kw/kg of output (idk if that's just plant material or food) - and an indoor vertical farm is closer to 40.

The first thing that comes to mind for me is that cities are usually pretty far from the farms. This leaves farmers and those wishing to buy from them with long supply chains. In my experience, people that live in cities have never really had fresh vegetables before unless they've personally grown them.

With this in mind, I can see a large former factory building being converted into vertical farming and then selling fresh produce, year round, to select clients at a premium.

Being able to farm and produce year round is also quite a nice bonus. You can largely ignore the weather, except where it impacts your supply chain.

All that said I think it's a fine idea and a great use for previously used industrial spaces.

> The first thing that comes to mind for me is that cities are usually pretty far from the farms.

This isn't actually that true though.

Even in places like San Francisco or Seattle you can find farms and greenhouses within 10 miles of downtown. Moving them, like, 5 miles closer at the cost of millions and millions of dollars doesn't make much sense.

The long supply chains are for things like avocados or apples or prepackaged salads. All things that vertical farms don't really do.

> In my experience, people that live in cities have never really had fresh vegetables before unless they've personally grown them.

This is a hilarious argument to me because most grocery stores in our area already offer hydroponic lettuce and tomatoes, but they are sold as an inferior product to the stuff grown in soil.

In places like Iceland where electricity is very cheap and sunlight not very abundant, vertical farming makes sense.

It doesn't make sense everywhere but nothing makes sense everywhere.

> why not just build a greenhouse, or just a regular farm?

There isn’t always space or proper conditions to do either of these, and that will only become more true in the next few decades.

> There isn’t always space or proper conditions to do either of these, and that will only become more true in the next few decades.

Because the solar panels needed to power the vertical farms will cover up all the land?

Vertical farms seem like one of those "take a solution, and split it up to create two problems" kinds of things.

If we can ship lettuce across a continent, where would this land constraint exist? Antarctica?

at geopolitical, climate, and market boundaries, for starters.

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