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I don't really understand the whole "urban agriculture" crowd.

People do often live in crowded cities, but there's plenty of space to grow stuff on outside of cities. It's the same kind of thinking that gave us the solad roads (which were, predictably, a catastrophic failure).




Urban farming only makes sense for high value, easily perishable produce. Fresh herbs, leafy greens, tomatoes, and other salad ingredients can be produced with higher quality when they are harvested and used on the same day, and when the plants don't have to be bred for shipment-and-storage durability. The real benefit is superior flavor and texture for quality-focused, price-insensitive eaters.

Note that this product site touts how much lettuce the system can grow.

More radical claims about how vertical farms will reduce CO2 emissions or feed a growing world population are aspirational to the point of delusion. Vertical farming isn't going to replace the calories that people get from potatoes and beans grown in big plots of dirt outdoors. If you ate potatoes grown in a nearby vertical farm instead of ones grown in Idaho and shipped across the country, you'd actually be increasing your carbon footprint.

It takes only a little energy to move a potato a thousand miles cross-country. It takes a lot of energy to grow a potato under artificial light. Even though renewable energy is ~20x better in life cycle emissions than fossil energy, it takes more than 20x as much energy to grow potatoes under artificial light. From a CO2 life cycle perspective you're better off eating potatoes that had ordinary diesel powered tractors, trains, and trucks involved in their production and delivery than to eat potatoes that were grown in a wind-powered vertical farm next door to you.


This is a false choice. Urban agriculture doesn't need to mean indoor agriculture / relying on excessive electricity / complex equipment etc.

Cities can be plenty dense while still having enough space for people to grow potatoes for themselves and their neighbors.


You’re right. Urban farming with sunlight is fine. My energy arguments only apply to growing under artificial light.


Is it? That seems like a poor use of space that could be dense housing, commercially productive, or a wonderful park.


It would be helpful to quantify "plenty dense" here. Paris has a population density of 21498/km2. Turning that around, that's roughly 46 square meters per person. That doesn't leave a whole lot of space for a potato plot if you're supposed to cook and eat those potatoes somewhere, too.


Source?

AFAIK traditional artificial light sources do indeed dissipate much more energy for the same amount of 'useful light', and also produce so much heat that they cannot be placed near the plant.

Is artificial light mandatory in urban farming? Aren't some (non fiber-optics-based) "light tubes" able to transmit light along with the necessary UV?


Nope! You can grow plenty of potatoes with sunlight in a plastic barrel on the balcony of your high-rise apartment.


Artificial light isn't necessary, but it's more space efficient and allows you to grow more plants per area which helps with the typically high land cost per square foot in urban areas.


These arguments are often lost shen people believe in something blindly. Tomato grown in Spain and flown to England will end up costing our earth less than the smae tomato grown in England because of additional energy to keep it worm required.


Isn't cogeneration, or any other type of "waste heat" recovery (for example from datacenters https://www.datacenterknowledge.com/data-centers-that-recycl... ) able to at least able partly solving this?


Food production in US is increasingly consolidated into hands of large agriculture corporations. Why not decentralize, make the system more robust to shock (look what's happening with grocery stores today)?


I entirely agree, this would be great. I don't see why it has to be done in cities though. Farmers in smaller co-ops can provide a similar decentralisation.


Not all parts of US can be farmed


The grocery stores are low on stock because of selfish people panic buying, not because there's not enough food. The supply chain is still functioning normally.


The supply chain is functioning normally, but "normal" means ~40% of food consumption in urban areas occurs via restaurants. The supply chain isn't designed for 100% of folks buying groceries at the supermarket and preparing their own food.

And that's sort of the problem. The normal centralised supply chain optimises for normal usage patterns, and adapting to abnormal usage patterns causes widespread issues in the short term.

A decentralised supply chain is (at least in theory) better able to adapt to local distrubances.


How do you imagine a de-centralized supply system, with each urban area's cell optimized for 40% of produce going to restaurants, would respond differently?

You're absolutely right. De-centralized systems can definitely respond better to local disturbances. Conversely, they're sometimes more vulnerable to larger scale disturbances that can more easily overwhelm the capacity of smaller systems to absorb shocks.


The system looks pretty damn robust given that we've just shut the global economy down and the food still keeps coming in. Maybe with some hiccups but that's complaining at a high level.

The reason decentralization doesn't make a lot of sense is because we need to produce food cheap and at scale to feed the world. Putting thousands of dollars into vertical farming equipment that doesn't fit into the apartments of most people on the planet is kind of silly.

There's also simply division of labour at work here. It's uneconomical for large portions of the population to spend their time farming.

It's essentially just a recreational hobby for wealthy people or maybe reasonable on a Mars Colony, but here it does not make much sense.


True, but it is very nice especially in the winter to have bright lights and green plants in your living space. That alone is worth it for me, having something to eat along the way is just a bonus.


If (a really big IF) solar panels can get efficient enough while LEDs also become more efficient, in theory plants grown indoors being fed by LEDs attuned to the precise portions of the spectrum they need with the whole thing powered by the solar panels, you could get a better yield than outdoor growing. Figure out cost effective fusion, things get even better. But neither is the case right now.

As far as the urban agriculture crowd goes, they're concerned about the length of their logistics lines to their tables. Raspberries grown half a mile down the street in winter is better for the environment than flying them in from another hemisphere... provided you get the energy costs of the indoor farming system low enough.


Until you genetically engineer a more efficient plant and your back to a net loss even assuming absolutely free panels and LED’s etc.

Vertical farming only really works as either artistic preference for maximum visual appeal or the kind of science fiction where you assume only a small handful of technology advanced.


If you can genetically engineer a more efficient plant for growing in a field, you can genetically engineer a plant that's more efficient to grow under LEDs, no? I don't see how a hypothetical breakthrough in generic engineering makes vertical farming a mad fantasy. There are certain crops that can't be grown in high yield monocultures and have to be transported from other parts of the world. I'm sure there are many cases where the math works, and I don't think most people are talking about growing corn indoors when they talk about vertical farming.


If a genetically engineered plant gathered energy equally across the full spectrum then frequency shifting using solar > LED is absolutely pointless even at 100% efficiency. Solar panels and leaves are solving the same problem using the same physical laws.

But that’s hardly required as solar panels to LED’s can’t reach 100% efficiency. Further, the limited lifespan of solar panels and LED’s means you need to cover their construction etc which requires resources.

Ultimately, looking at theoretical limits it’s simply a net loss.

PS: Monoculture is far from required, it’s an outgrowth of current automation rather than having any theoretical advantage.


There is no need to breed plants specifically for LED lights. All the newest and most efficient and cost effective LEDs are white spectrum now and emulate the sun far closer than any other light ever has. What matters is how efficiently can you make the lights run, and right now it is pretty damn good getting about 200 lumens per watts on those grow LEDs (versus about half that for a shitty standard household LED)


Isn't it counterproductive to waste LEDs optimized for our perception to plant growth which doesn't fully utilize the spectrum of sunlight? I thought that is WHY grow lights have this purple sheen, be it traditional flourescent ones, or contemporary LEDs, or a mix of red and blue ones.


Despite the 'common knowledge', plants do utilize most of the visible light spectrum, even green, just in different amounts. And on top of that these white LEDs aren't just a single static white, their light spectrum are tuned to specific growth spectrum and can be ordered however you want, but all come out visibly to us as white of slightly different shades.

Those blurple lights are just awful, and not only do the LEDs have far less energy efficiency being old tech, but their supposed "optimal" wavelengths are anything but. They are blasting out extremely narrow wavelengths of light and trying to make it more continuous by using a bunch of slightly different narrow range colors, but it doesn't work as well as one would hope, especially when they are coming from different point sources.


> As far as the urban agriculture crowd goes, they're concerned about the length of their logistics lines to their tables. Raspberries grown half a mile down the street in winter is better for the environment than flying them in from another hemisphere.

Aside from environmental effects, it’s also just a more secure logistics chain. A person needs water, food, and shelter to survive. Sometimes it feels strange to me that the trend of the past centuries has been to increase the distance between a person and those sources — to introduce more points of failure between you and the things you need in order to survive.


Another commenter mentioned it's more energy efficient to grow tomatoes in Spain - where less heat is needed - and fly them to the UK. That may be true, but an even better way is to just grow crops that are suitable for that season.

In the UK you can grow crops all year round outdoors [0], and the growing seasons could easily be extended with a passive greenhouse (polycarbonate is more insulating than glass). You can also use tried and tested preservation techniques like canning and fermenting to keep food for other seasons.

[0] https://www.gardenorganic.org.uk/vegetables-all-year-round


Unless you do pull out fusion, you will always have too huge loss between solar panels and LEDs. As efficient as LEDs are now, and I know because I just built 1200 watts of the latest and most efficient LEDs that are available, they are nowhere near cost effective in comparison tot he sun. Plants are not nearly as inefficient as people believe, especially when you consider the fact that solar panels themselves can also only absorb a small fraction of the light spectrum.

That 1200 watts is only really covering a 6 by 6 foot square worth of growth area at about 35 watts a square foot at 200 lumens per watts. It could be slightly larger but only if you want most plants to grow extremely slow or be really weak, and you can go up to 50 watts per square foot before requiring supplemental CO2 but not all plants like that amount of light.

Converting that to 1 acre worth of coverage, which is what is about what is needed to feed a single human for one year, you are looking at about 1,500,000 watts running 12-18 hours per day. That is a ridiculous amount of energy. Even assuming you can get away with 1/3 of that area by super careful and efficient growth year round that is still a half million watts in lighting costs alone. Not to mention all the other work and costs.

I don't see indoor farms being good for anything other than extreme specialty plants or extremely fragile plants until we can pull essentially limitless energy out for far cheaper than we can get even with fossil fuels.


I am curious about the 36 sqft (3.34 square meter) and 1200 watt. As we end up with considerably less watt per area. We use about 100 watt per square meter. You have about 360 watt per square meter. So we use less than a third. Preliminary tests show very good growth rates. We will have better data in a few months.

This is for an indoor leafy green, mostly sallad, aquaponics growing facility.


Technically I can still get growth down to 11-12 watts, closer to your levels, but it is definitely much slower growth and it won't be enough later on. Technically I run about 20 watts during the initial vegetative state, but once plants start flowering or fruiting there is a markedly different end result if I don't turn the lights up to around 35 watts a square foot, which is what most other people ive seen report. I mostly just run it at 35 all the time because I want them fruiting and producing as much as they can as fast as possible. But if you are growing leafy greens your plants are never even entering the flowering stage because you will be picking it by then.

Perhaps with a bigger more automated setup I could do slower growth, but there are other costs like ventilation or dehumidification or possibly heating or cooling too that don't really change a lot whether the plants are growing fast or slow, which makes faster growth possible optimal financially, even if I might be losing out a few percentage worth of light absorption.


Ok, we don't have fruiting plants. So that can make a difference.


Indoor you could surround the plant with mirrors so more light gets input into the plant. Also no wasted water.


I think I read an article at one point that most "urban agriculture" and indoor farming tools were originally funded with the expectation that they would only be valuable for cannabis production. Because while you could grow tomatoes and lettuce indoors if you wanted to, it's really only economical to produce cannabis. I think that's still true today.


This is true to an extent, but I certainly wouldn't say it's the case for most. From my observation working in the field it was really only a thing between 2013-2015.


First, it's independence from the industrial farming infrastructure of the USA and knowing what fertilizers went into your food or medicine. Produce sold in your local store are the 'industrial' versions which are genetically bred for transport, storage and presentation over taste.

Second, it's climate change which is making outdoor farming more and more difficult by the year, as well as a push towards higher efficiency. Also, having a garden (or being around nature, things growing) has been clinically shown to reduce stress in humans.

Third, it's MUCH less climate impact to transport renewably sourced electrons over a regional grid than it is to transport decaying produce in cold storage to a grocery store. Free sunlight is still cheap, but creates dependence on the seasonality (frequency, duration) which means a variety of crops are totally non-viable in certain hemispheres. Full outdoor growing has a much higher level of exposure to pests, requiring pesticides -- whereas indoor growing under lights gives you a higher level of defensibly without that risk.


It appeals to me. Even if the cost was higher, building the capability locally seems very valuable. As well, not all costs are monetary. If the pollution is lower (e.g. from eliminating transportation) it may be worth paying the higher price.

Another appeal is knowing exactly what goes into your food.


Most of the pollution from food production comes from actually producing the food. Things like tractors and stuff use a lot of fuel.

Furthermore, putting farms in urban buildings means that some urban businesses or residences will ha e to be moved further out, increasing pollution. In reality, this would move the pollution to the urban areas, and not reduce it.

Lastly, I can’t think of a reason that you’d know more about farming practices if it happens in an urban environment than in a rural environment


No, most of the pollution from food production is from fertilizer. Nearly all commercial fertilizer sold is artificially derived from fossil fuels and pollutes just as bad as burning it. Over 60% of the world's total crop yield is the direct result of fossil fuel-derived fertilizer. Removing the fossil-fuel component would make fertilizer production alone rival the current total energy demands of the entire world on that single task.

Tractors are moving tens of thousands of pounds of material at a time and are extremely efficient for the energy they utilize. Tractors may seem like they are using ass tons of fuel from looks alone, people see the huge engine and big cab and chunks of large steel and think it just eats fuel to produce crazy tons of power, but many consumer cars have more horsepower than tractors and frivolously spend fuel on saving mere seconds in both acceleration and braking which are huge wastes. Tractors don't accelerate for long periods of time or waste tons of energy braking all the time just for personal convenience. Tractors are just geared down super low and built ultra-robust with zero concern for physical size. The run better and more efficient than car motors specifically because they didn't have to make any trade offs for compactness, weight, or engine and transmission form. How many cars have turbos and super-chargers? How many of them are tuned for fuel efficiency rather than peak performance? Tractors commonly have them for the sole purpose of fuel efficiency, they never lacked power in the first place because of the lack of other restraints.


The point about displacing people and businesses is only true if real estate is in a fixed quantity. When building is a possibility this is not a zero sum game.

Given the (OP) solution, I was imagining having a broccoli wall in my apartment. This would give me a lot more insight into the farming practices as I would be growing it. Also, near zero transportation externalities.


Perhaps if the externalized costs of the pollution were more efficiently passed on to the consumer then the benefits of localized urban aquaponics might be enhanced.


Look at the Netherlands. They have no land and one of the largest agricultural producers in the world.

More efficient, cheaper, better for the environment...the benefits are pretty much endless. It isn't about "urban" but using what we have more efficiently.


>They have no land and one of the largest agricultural producers in the world.

That's a bit of a misconception. Most people get the impression from the headlines that they produce a lot of food, but that is not really the case. The Netherlands is the world's second largest EXPORTER of "agricultural products", by dollar value. 10% of that is consulting and equipment. Another 10% is flowers. Those are not food. Even in the remaining 80%, it is mainly products that are high in monetary value, but low in land efficiency, like cheese and flavorless hydroponic tomatoes. The Netherlands actually only produces 50% of the calories needs of their population, and exports away a good chunk of that. They rely on importing staples to feed their population.

>More efficient, cheaper, better for the environment

The Netherlands model is none of those things. It is just used as a propaganda tool for a corporate greenwashing campaign to convince people that spending lots of money on environmentally destructive and wasteful technology is good for the environment, when it is actually being done because it is good for the bank accounts of a small minority of wealthy people.


In Japan there are also some pertinents operations.

Mirai ( http://miraigroup.jp/en/ ) states some benefits.


What are "solad roads"?


Typo for 'solar'?


I it was intended to be solar roads.


I was imagining salad roads.


From personal experience, in Virginia and the pacific northwest, you get plenty of berry roads. Roads literally lined with prolific blackberry bushes and sometimes raspberry bushes too. Seriously, these things are weeds. Especially raspberries. They're fucking delicious weeds. During season, plenty of folks park on the side of the road to pick berries. These road berries are better by magnitudes compared to store bought ones.

I have yet to see salad roads, but would love to see it. Diversity is "weed" edibles would be awesome.


Depending on the traffic loads of the roads i'd be wary of eating them for 'organic' reasons. The same goes for the embankments of railroads which are sprayed with herbicides, at least where i am.




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