Vertical farming: Does it really stack up?
economist.com
economist.com
According to the World Bank we're already at almost 6.8 billion people. This means we'd need to feed an extra 33% of the worlds population, meaning we'd need approximately 33% more food as our food usage already factors in losses from production, delivery, etc.
The only way you get 70% is if you made 9.1 the divisor when it is the dividend. You take where we will be 9.1, divide it by where we are 6.8 and you get how much more production we need 33% (IE 133% of present). If 9.1 is the divisor you get ~75%, more likely 70% as this will have been based off of a few year older (but likely slightly more accurate) population counts.
So, to put it simply, a whole bunch of people in the UN can't do basic math.
> Soil erosion will not be a problem because the food will be grown hydroponically—in other words, in a solution of minerals dissolved in water.
In other words - it will taste like nothing. Ever tried a hydroponically grown tomato? Ever tried one after eating a local vine ripened or even a home grown tomato? If you have, I bet you never tasted the hydroponic tomato.
I've eaten hydroponic tomatoes over the past decade and never noticed a difference or improvement, so how long before its actually edible, and actually worth purchasing? I even frequently see the hydroponic tomatoes to be paler and more tasteless than even the cheap tomatoes imported from half way across the country that were picked weeks before ripeness.
Vertical Farms will be built where Vertical Buildings are built - cities. Cities contain a hugely disproportionate amount of western civilizations population and even more wealth. People in cities are generally paying for higher quality food than people in rural areas, so it seems rather asinine to construct vertical farms only to export the produce out of the city into poorer areas where hydroponic crops are more likely to be purchased.
Vertical farms would be far more likely to succeed if they were producing high quality foods, not low quality foods. Sell vine ripened tomatoes picked yesterday and you'll make a killing compared to the hydroponic tomatoes they would be selling. I've seen hydroponic tomatoes selling for 1/4 of the price of California vine ripened tomatoes (I live in ontario, we're the last stop, they're harvested like a month before they should be ripe). You should easily be able to make 8 times the amount selling 'harvested yesterday, vine ripened tomatoes' in a big city than you would hydroponic.
My contention isn't that vine ripened won't feed people. It's that they're planning on feeding the wrong people the wrong food which is just a market failure begging to happen. You might as well be trying to sell a Vegan some beef for how accurate they're targeting the local market.
You could get a luxury product, harvested within 10 miles of your home (beating the pants off of the 100 mile challenge) with as much freshness as farmers market produce and it's expected to be environmentally friendly, and could be made organic with far less risk of spoiling from pests and disease. All of these are huge sale points and none of them will be made with budget cost hydroponic crap.
If you built one of these, met all those marks, you'd be selling your produce to the local high end restaurants because your produce would be at least 2-3 days fresher.
Hydroponics is the equivalent of bottom-lineism in businesses. They're trying to reduce costs to boost profitability, rather than simply finding a way to raise the price that will keep people buying. Do you think Apple was looking at the bottom line when it decided to unibody aluminium shells? Or when they included a higher resolution screen?
Tech companies everywhere disregard the bottom line because they know people will pay for a superior product. Everyone here on HN knows people will pay for a superior product. Google had a superior product (not just technologically, but usability, etc. too) , and it nailed Yahoo that had poor search and poor usability.
Why sell an inferior product when you can sell a superior product, maximize your profit per sq ft not minimize it. Produce a tomato worth $4/lb not $0.99/lb-continuously on sale for 1/3 off. Make an eco-organic-super-fresh tomato and sell it for $8/lb and sell it to rich idiots.
Going vertical just spreads the same amount of light over a broader area. Your yield only increases if you use electric lighting, which is only economically viable if electricity gets very, very cheap. Using vertical sheds to farm cattle doesn't help, because the land use to house cattle is negligible compared to the land needed to grow their feed. Vertical farming doesn't help reduce soil depletion, because it depends on what we use now to amend poor soil - oil-based fertilisers. Vertical farming is a perfectly reasonable solution if we solve cold fusion, but there are a whole lot of other problems that magically disappear if we discover a limitless source of practically free energy.
Food is just a proxy for energy and any future food crisis is likewise a proxy for an energy crisis. Much as it'd be easy if we could solve it all, we can't. We've been living on millennia of stored energy and that store is coming to an end. We cannot escape the fact that we will have to dramatically reduce our energy use. Easy solutions to the problem of energy are tremendously appealing, but the laws of physics are a harsh mistress. The future of our species rests entirely upon joules, watts and kilocalories. Vertical farming is an appealing but irrational fantasy, rooted of the same fallacies as food pills and jetpacks.
I'm not sure I agree with this statement (though I like your first two paragraphs)...in the end, couldn't we replace most of our fossil fuel usage by just ramping up nuclear? I'm pretty sure there's enough supply there with breeder reactors to power our civilization long enough to invent something else.
We cannot continue to act on the hope that some future generation will fix our energy problems with a hypothetical technology. It is energy policy of the dot-com bubble. There is an outside possibility that technology might save us, but it is just that, a possibility. There is no roadmap, no plan, merely some things that might work, maybe, some day. Without such a hypothetical breakthrough, there is simply no possibility of continuing our current rate of energy production.
I highly recommend Dr David MacKay's book "Energy Without the Hot Air". In it, he surveys the production possibilities of all the currently viable technologies, gives current consumption levels of British people, and leaves the reader to decide how to make one number match the other. It is impeccably researched and available to read for free online - http://www.inference.phy.cam.ac.uk/withouthotair/
>The next generation of reactors in development are only around 15% more efficient than the best extant facilities.
I'm not sure what figure you're referring to, but breeder reactors with full reprocessing are 200 times more efficient than LWRs.
Breeders might hypothetically be very efficient indeed, but the plants we are actually building or have actual plans to build are PWRs and BWRs with only marginally better efficiency.
However, from a practical perspective, I do think that ideas such as vertical farming are a step in the right direction for a host of other reasons, assuming that the energy issue gets solved.
Vertical farming seems better for the environment since we're not taking down more forests to claim farm land. It also seems like a great idea for developing societies that can't meet base consumption levels. I'm sure there are other great reasons too, but my point is that this type of thinking certainly turns the wheel towards the direction you're pointing to.
However, if you look at vertical farming as a series of low-rise greenhouse warehouses ringing a city, like a lightly stacked up Thanet Earth, then I think there's a strong case for them.
Cattle actually come close to this because they don't need sunlight to grow so you can have multi story feed fed cattle farms. However, it's still cheaper to use more land than to build multi story cattle farms.
Why?
While suburbia may offend you, replacing suburbia with hive-living wouldn't significantly increase the amount of arable land in use.
The places that have food shortages have them because of bad governance, which hive-living won't fix.
And you know this, how? Let me suggest that you probably overstate the costs of suburbia.
> And I think a characterization of "hive-living" doesn't nearly do justice to the cultural, social, and economic benefits of a vibrant city.
You're assuming that everyone values the things that you do in much the same way. That may be true of the other folks in your tribe, but extrapolating universality from that demonstrates my point.
As far as "hive" goes, it's apt. It's accurate and the connotations point out the other side of the claimed advantages.
> Be open-minded when calling for openmindedness.
I'm not calling for openmindedness. I'm pointing out cherry-picking, and a couple of other problems.
I don't care where other people choose to live. However, if they're going to argue that their choice is superior, I think that it's fair to see if their argument makes sense. What part of that do you disagree with?
Which reminds me - I'm certain that I'll see you make the same complaints when an urbanist commits my sins, right?
10 people can work together and use 10 plots of land more efficiently than 10 individuals using 1 plot of land each. We just don't have a land shortage to the point of making availability an issue.
I'd argue it'd only become tenable with high land costs. The cheaper energy is, the less sense vertical farming becomes since it makes the transport costs from far away, cheap-land areas even lower. If real-estate in and out of a city are roughly the same (no cheap pasture land!), then the farm can be more or less any location, that includes in a city. But for that to happen, would probably imply some kind of Judge Dredd continent swallowing city first.
The scenario for this would be if the green houses grew themselves... which isn't utterly unimaginable.
Consider a red-wood sized tree/vine that gave high-protein fruit. Perhaps it would use just a bit of human-built scaffolding.
Even modern feedlots only takes cattle after they've spent a while grazing and quality of the resulting meat has been criticized. Cattle that spent all of it's life indoors could plausibly have many more problems than one see for today's meat.
It's an interesting idea for a second, until one starts to actually crunch the numbers.
This is one of the reasons it's so important for us to press on with technology and not just try to keep things the same; we need better, more cost-effective energy, such as with better nuclear power plants. If we have that, there's a lot of things like this that open up to us that can allow us to save energy in other ways. If we don't progress, though, we'll be stuck with a resource-expensive society and no way to escape from the trap.
Even with more cost-effective energy, this is still a terrible idea.
As for lighting, the trick is to figure out how to use natural lighting for a majority of the input. Obviously, again, this is why 100-story skyscrapers aren't practical, but sub-10 story warehouses could be. Although some are investigating architectural ideas like mirrors and other hacks.
No, that really is impossible. Mother Nature's little growers are optimized for the amount of sunlight they receive on flat ground, and by trying to stack farms on top of each other you utterly inevitably mathematically reduce the amount of sunlight each floor can get to substantially less than that, because the floors occlude each other, except the top floor. To the extent that people fail to take that into account they really are failing at physics badly and Monbiot is correct to criticize them.
I think under the right circumstances and with plausible technological development this can make sense, but he's absolutely correct that doing it with current technology is completely infeasible and useless. My position is actually not what he is criticizing, and I'm still open to the possibility that while the future may look different, the actual best solution is something not yet evident. We may also simply reduce the costs of transportation such that growing something 1000 miles away simply isn't that big a deal ecologically. (We really, really, really need cheap energy, cheap in all senses of the term, ecologically as well as economically. And there are feasible possibilities.)
And sub-10-story warehouses only magnifies the problem-- then you need to buy even more city blocks.
Purchasing land 30 miles outside of a city falls well within the confines of urban agriculture, especially since indoor ag means a year-long growing cycle. This means that Detroit or Iceland don't need to rely on South American growers for certain seasonal items.
The small shipping distance necessary for putting these in New Jersey, greater Chicagoland, etc., there's no argument against that, but yet, people keep citing downtown Manhattan as impractical for farming. Of course it's impractical for farming, it's damn near impractical for living.
Is that actually true? Crops are grown in a pretty wide range of locations, and sometimes the same crops are grown in different locations with quite different insolation. Surely there must be at least some set of [location,crop] pairs where the crop needs less than the full amount of sunlight available in that location?
I also find it hard to believe that you could find 10 layers' worth of crops this would work with. Two or three, maybe, but I would be astonished by more than that.
I don't think this will work. Some numbers:
* USDA says 70 bushels/acre of wheat is the average yield for irrigated fields [1]
* perhaps a theoretical 3 harvests/year [2] could be possible in a climate-controlled building (it takes 110-130 days between planting and harvest), for 210 bushels/acre/year
* solar irradiation amounts to an annual average of about 4 kWh/day/m^2 = 170 W/m^2 in the wheat belt [3], or up to about 6.5 kWh/day/m^2 = 270 W/m^2 average in July
* March 2011 wheat futures are $7.67/bushel on the CME [4]
So I reason: with the cheapest $0.05/kWh electricity (nuclear, hydro, or coal at large-buyer rates), the cost to imitate sunlight, with "100% efficient" lighting (maybe LEDs), would be in the range of $300,000-$500,000/acre per year [5]. (I think the higher figure is closer -- it corresponds to sustaining July-level insolation year round, which would make sense for year-round planting). Which divides up to about $2,500/bushel -- over 300 times current prices. (For household-scale perspective, this is $70/liter).
You can get incremental improvements in power plant economics, but not orders of magnitude (not anytime soon). Given current technology and economics, this idea falls apart.
[1] http://ww.agcensus.usda.gov/Publications/2002/Volume_1,_Chap...
[2] http://en.wikipedia.org/wiki/Wheat#Agronomy
[3] http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/ (use "horizontal flat plate")
[4] http://www.cmegroup.com/trading/agricultural/
[5] calculation: http://www.google.com/#sclient=psy&hl=en&q=0.05+USD%...
The missing next step in the analysis is to break out the concept of penthouse farming. Penthouse farming is different from vertical framing in that penthouse farming only farms the top floor, using daylight through a glass roof. Lower floors are flats or offices as usual. If vertical farming makes any kind of sense then penthouse farming should be very profitable.
The path to vertical farming looks something like this:
o penthouse farming starts and is just about viable
o improved techniques boost yields leading to fat profits, almost enough to cover the cost of electricity for grow-lights for lower floors
o cost of electricity falls
o vertical farming profitable!
>The immediate opportunity may simply be to take advantage of the space available on urban rooftops
You know, I don't grow anything on my land but grass and a few decorative plants. Where's my government handout?
The dirty little secret of all these vertical farming stories is that the numbers don't add up. The Sunday NYT had an article where they talked about growing corn in one of these buildings.
If I gave you the building and the land you couldn't make money growing corn. They speak of turning a crop every six weeks, I don't know of a single hybrid variety that matures in less than 78 days. Quite simply the NYT reporter didn't ask any critical questions.
Even with high value crops like lettuce and flowers it is dubious. But farming vacant urban land with hoop houses like they're starting to do in Detroit does make sense, There are security risks in an urban environment but those pale beside the costs associated with twenty stories of hydroponics.
I don't see why this wouldn't work for high-profit produce like tomatoes or peppers, though.
You might possibly get away with some kind of balcony arrangement on the southern face of the building, where all levels would get sunlight, and the rest of the building could be offices/residential/whatever. There are still going to be huge inefficiencies in planting, tending, and harvesting compared to open-field farming.