OCT 26

The reason why using food for fuel doesn't make sense is because you're taking a valuable input to make a slightly more valuable output...but for great cost. In comparison, using shavings for fuel would make more sense. By the same token, instead of setting aside city land to grow farms, in the future we may grow food on rooftops. Granted, there's a weight issue, but they're not be used for much right now; that land has no opportunity cost.

There is, actually, a cost to putting a farm on a roof, and it's not cheap. Getting the dirt up there, having a safe way to reach the roof regularly, installing irrigation, getting the soil up there in the first place, maintaining the roof, etc.

Lets see, 1 acre is 43,560 square feet. That makes $43,560 per acre, which is off by a factor of almost exactly 10. Good, fertile farm land is about $4-5,000 per acre. The biggest problem I can think of is labor. Farmers use huge tractors and whatnot to work the land. Doing in a building would require individuals to plant and harvest each and every plant, instead of using a tractor. Big problem.

It is a very good point that vertical farms can't feed the cities efficiently. However I think that the nitch for vertical farms not commodity crops, I whole-heartedly agree that makes no sense. Rather it is with high value horticultural crops, particularly those that don't ship well or require refrigerated shipping where the advantages become realistic. I'm talking about tender greens, day neutral strawberries, things where freshness and quality really matter, luxury crops.

Having plant life on the south side and the roof top of a building can help to insulate against heat, and produce clean oxygen while at it. Can't the roof top be used to capture rain water? which would lessen the need to pump some of the water to the top. Perhaps large scale operation isn't practical right now, but I think there's benefit in having plant life be integrated into high rise bldgs.

There are some valid challenges presented here, but I take issue with one false assumption: that the interior of the building space must be filled with plants. This is, of course, impractical because they'd have no access to natural sunlight (as indicated). Many of the z-scale farm designs I've seen do not fill the interior of the building space, rather they line the perimeter walls, or maybe the roof--that is the point, after all--reducing the planar footprint of the operation and converting it to a vertical space, freeing up the horizontal space for copiers and cubicles (or whatever). Also, the water pumping issue has already been solved by the plants and trees themselves: you can take advantage of water's wicking properties and capillary action by scaling down the tubing and leveraging the same processes that trees use to get water to their highest boughs.

So, basically, food grown this way is going to be even MORE expensive to the public, in order to cover the cost of renting building space?

There are a lot of empty office buildings in downtown Seattle right now. I'd assume the going rate for that type of space is getting really cheap! (Not to say that I think they will start filling up with farms... but any assumptions about how expensive "office space" is can change quickly depending on circumstances.)

The south facing wall of a skyscraper has a huge amount of insolent (sun receiving) area compared to the roof which is the equivalent area of a farm.

I don't see it being fiscally solvent without renting out the other 90%+ of the building in office space..

But green roofs and walls serve huge benefits in temperature control and air purification. Who wouldn't want to work in that office.

Is a green wall a kind of vertical farm? or visa versa ?

The pseudo science is hilarious. Here we have a 'web journalist' citing a science fiction writer to bolster an opinion.

Farm the sewers. This is real city real estate that is not competing with too many people for office or living space. You would just need lights and maybe some mirrors or magnifying lenses. There is already scads of fertilizer there(a hydroponic sludge), and water, and it's climate controlled never getting too cold and electricity hookups already run through a lot of it. The plants may even clean the water (a boyfriend's uncle once gave me the tour where he worked treating dairy waste water by running it through vats of tropical plants before letting it out of the factory). No it wouldn't be organic coming all most entirely from waste water. I wouldn't eat the lettuce but lots of stuff is grown in fertilizer and manure...and maybe something useful to cities could be grown there... perhaps biomass? then it wouldn't fight for farmland.

First of all, yields in order of magnitude better than conventional farms are not unheard of, especially when you're dealing with something like a hydroponic system or even an aeroponic system. Secondly, growing fresh produce that does not need to be treated or processed is fairly straightforward if its just tomatoes or lettuce that get delivered via courier straight to a restaurant kitchen or supermarket. Unused or marginal space, such as rooftops of industrial or office blocks would not be expensive, and if the farm was automated, like Valcent Products' automated urban farm, then the labour required would be minimal.

While "web journalists" citing "science fiction writers" certainly isn't the way journalism generally gets done, it's a heck of a lot better than Popular Science or even The New York Times writing stories about vertical farms without even stopping to consider the economies involved and the assumptions made by people promoting these technologies.

They're writing about it because it's sensational and interesting and there are lots of pretty pictures. And that's the end of it.

I think what I'm doing is better than that, if only because I'm trying to present you with some details and don't claim to be the beginning and end of factual information.

Great article, and you're right, besides all the pretty engineer drawings of the utopian urban design, there is *never* any discussion or input by economists on *any* of these "great new inventions".

Keep going, Hank!

I agree with those who have suggested that the answer is not to build skyscrapers specifically to become vertical farms, but to use wasted space on otherwise occupied buildings to grow plants, especially aeroponically (without the need for heavy quantities of soil or water). Heck, even if the plants covering the roof and south wall of a skyscraper weren't food plants, they would still confer a benefit in terms of environmental effects: temperature mitigation, pollutant filtration, etc. I also agree that the most cost-effective crop-growing purpose would be the easily-perishable luxury crops that are often used fresh and have to be shipped by air to their destinations, like strawberries, or those which are typically picked green so they'll survive the journey and therefore aren't worth eating once they arrive, like tomatoes.

Wow, there are some great comments here! I have to say that the theme of the article is right on, even if some of the numbers are a little off. I have a business growing hydroponic lettuce in urban greenhouses to reduce transportation. But transportation is not the only issue here because that only contributes anywhere between 10-25% of the actually energy input per plant (no cite, these are from my calculations from research). Plus, transportation accounts for about 25% of the cost of the plant to the consumer (only for lettuce, from the USDA). The rest is packaging, processing, refrigeration, etc. So vertical farming only takes into account the transportation, which as this author so astutely realizes, is not enough to make up for the total increase in energy usage. The other factors that can be argued, such as food security and land usage, can be easily answered by more evolutionary hydroponic technologies that leverage automation to increase efficiency. Flat, meaning ground level, hydroponics that use sustainable nutrient supplies can use just about any land available regardless of soil quality. If you integrate green energy sources into the equation, you'll be able to reach far higher levels of efficiency than traditional farming while reducing transport.

That's my two cents, from someone whose business relies upon it

The current issue of Scientific American has an article by the originator of Vertical Farming. I haven't studied the details, but this seems like the perpetual motion machines.

A one layer farm uses daylight for solar energy-- to grow vertically electric lights are required. In the article, they propose burning crop residue to generate the electricity for the lights (and excess for city), but since plants are very inefficient in energy conversion, much more energy would be required for electric lights than what could be recycled from biomass.

Jack had the right idea when he sold that damn cow and planted a giant beanstalk.

I'm looking for a transmission tower to plant next years string beans.

we are so selfish when it comes to cost. nobody thought about how much land it could free up for nature. a 10 story building for 10 farmers would free up land for other 9 farmers for nature. In the long run this idea is effective.

And according to my calculation the yeild is 10 times which could help

There's no doubt that the food demands of our nation our increasing out of control and causing us to put magnitudes of stress on the already "tired" land. However, the concept of vertical farming is one worth looking into if we are planning on solving our future food problems. While it may not make sense inside of buildings, it does make sense in rural areas and farm land where the infrastructure is already available to support things like wide spread irrigation.

This will not be the ONLY answer, as people in urban centers will inevitably have to adopt self-sustainable gardens in some fashion or another in order to supplement their needs in a practical way. The system isn't perfect yet, but we're getting there, slowly but surely.

This may be a possible solution to lighting (tech may not be there yet, but in the future...)

see video: Hybrid Solar Lighting System Employing Fiber Optic Cables

http://www.youtube.com/watch?v=DBsmkHcFd3I

There are more videos on youtube, but this was the first I found.

"a quick glance at the actual economics of farming shows that this isn't ever going to work."

There are already several urban projects doing hydroponic and aquaponic (combined fish and crop) greenhouses on the tops of buildings and on piers and they are quite profitable.
Of course you could do these same type of projects in the less expensive real estate outside of the city, but the comparison of conventional farming vs hydroponics shows hydroponics uses less energy, land, water, fertilizer, insecticide, and creates less chemical runoff and less opportunity for contamination.

Was anyone ever talking about farming INSIDE skyscrapers? I don't think the external square-foot price is the same as the habitable floorspace inside. Is this just a mistake or did you just not state some of your assumptions?

On the one hand: Land is precious. Building suburbs, freeways and mega-malls on good farmland near cities is criminal, but common practice. Clearing rainforests to create marginal farmland so produce once made on good farmland near cities can be shipped around the world is insane, but common practice.

On the other hand: The cost of building skyscrapers is huge. The cost of running them is huge. Few people have begun to grapple with the cost of replacing them when they reach their use-by dates, but it will be huge.

None-the-less, skyscrapers are spectacular. People with more money than sense (and people who have easy access to other people’s money) love them. The images of immense vertical gardens are spectacular. Ditto.

So where does that lead us? Nowhere. At least in most western countries, building skyscrapers is not an alternative to sprawling suburbs; they are conjoined twins. Vertical gardens are the companions, not the replacements, for the parking lots around the mega-malls. This vertical garden fad is almost as much help as contemplating Paris Hilton’s reading habits would be for planning a Sunday dinner. Go for it Hank. Pull the plug.

Clusters of skyscrapers surrounded by vast low-density suburbs are not the only option for urban development. The media may believe that manufacturing big sparkling celebrities surrounding by masses of tiny dull admirers is the best way to entertain people, but it is not the model for sustainable cities.

And neither are cities - so how about we focus on the marginal benefit of vertical farming, as opposed to pooh-poohing the whole concept before it ever gets started?

Attempts to transform human kind into some sort of benevolent force for world peace, are as likely to fail as every other utopian concept ever tried; attempts to figure out how to make what people are already doing just a little bit better, well - we call that progress.

People live in cities; people like living in cities. People eat veggies; people like eating veggies. It doesn't seem like an impossible goal to figure out ways to put the people and the veggies closer together.

Vertical farms may not be effective for you but vertical farms do make sense to countries like Singapore that have to import 98% of there food. Yes,
some methods to this type of farming is costly but
you have to look at all the variables before you deduce
that something does or does not make sense. Dynoponic
farming grows food WITHOUT using water. That eliminates
one variable. Hydroponic farming does use water,but
you can use rain water collected from rain barrels to
water the plants which offers another sustainable alternative. You have to read and learn about green
technology almost daily to get insight into sustainable
living because it's ever advancing, so keep reading and
start broading your perspective because every community
is different and has different needs. It ALWAYS makes
sense to plant and smaller farms yield better produce
than bigger farms,anyway. Vertical Farming DOES make sense.

Given that there are no sources for all this information that he is spewing, I will call bull$#!* on most of this. Yes, it will be more expensive. But look how much people pay for "Organic" food. People will pay the premium knowing its more environmentally friendly. Look at the market its going for, wealthy urban yuppies. The cost of the structure will be more than farm land but... We are Running out of that resource! The thing that is not mentioned here is that indoor farms can produce year round 24-7. And most proposed ideas use aeroponics (a form of hydroponics ) and not soil. So I am not sure about this talk of hauling soil onto roofs... but anyway Im sure the author is an expert and has many leather bound books and an office than smells of rich mahogany... and cow dung...

I am always amazed at the comments on how something has to have monetary value for it to be worthy.I remember listening to a show on NPR and a guest stating making fresh water from saltwater would never be practical and dying of thirst is?We can keep fooling ourselves all we want but we all know that the relentless pursuit of greater profits year after year and the endless exploitation of our world will come to an end.One day and I hope I live to see it,humanity will live for things other than monetary gain.The philosophy of the pursuit of knowledge and the care for every living species on this world.Maybe just maybe someday.

At $200 per square foot, the price of food would need to go up 2x, and production 100x - not 100x price and 100x production. That would be 10000x.
For that matter, the whole economic evaluation is silly. You don't calculate the profitability of a business based on the cost of constructing the building it will be in. The question for vertical farms is how much revenue they will generate per square foot versus the costs of production. Skyscrapers often rent for something like $30 or $40 per square foot. If you really must make a direct comparison, that's the number to look at.

This article was referred to on fastcompany, where i saw it and picked up on the bad math. There are a lot of good comments here that challenge the false argument and lack of detail of the article itself. It's like a lot of these blog magazines these days - the comments are smarter and have more information than the article. And yet we don't get paid.

An interesting read, especially with the comments, but it seems like a bit of a straw man. Building a skyscraper specifically to grow staple crops doesn't seem likely or worthwhile, but incorporating food production along the south side of a building does seem like it could conceivably have enough benefits in a clever design. Also, the economics of development is more complicated than just price per square foot. If a city fast-tracked a development or agreed to allow a taller building with more units because several floors were going to be involved in food production, that seems like it could easily make an urban farming operation worthwhile for the developer. Similarly if the units sold or rented for more money because the farming aspect made the location seem more desirable, that too could make it economical.

And there are various crops that it is currently possible to grow indoors for profit. I'm pretty sure that it is already possible to rent space in a skyscraper and make money growing marijuana, orchids, and possibly other plants. Gourmet mushrooms are grown in retro-fitted warehouse space in urban areas; they seem like at least one food that could be profitably grown in a skyscraper. Maybe those are cherry-picked examples, but the point is that the idea of farming in a building can't be completely dismissed. The idea of vertical farming isn't just to eliminate fuel costs, but to also design a building as a system and find benefits from the vertical aspect.

I have a design called the Omega Garden which is a rotary cylinder with the lighting running down the center with the plants rotating around it. It is far more efficient then green housing, and they can go on the streets of many neighborhoods. It can be done as a non-profit co-op with the average consumer benefiting instead of large corps. See more details at www.yougrew.com

It could work if we installed them just outside the facade of high rise buildings, and parking structures, rooftops, etc. It would definitely have to be small time operations- nothing like modern day farm operations- more like backyard gardens. Maybe we should just push ertical gardens http://www.thechicecologist.co...sts-oh-my/ instead?

totally agree with you there. Vertical farms are just ridiculous. It's not like we're running out of land to build on, it's just that we're not utilizing the land that we have efficiently. And no, this does not mean we do vertical farming.

First, let me say that I agree completely with this article.

Second, let me continue with the fact that many crops such as tomatoes, cucumbers, peppers and strawberries are already grown vertically. (Not to mention profitably by many growers around the world.)

The biggest concerns should actually be availability of "good" water, qualified labor and quality light.

With good water, light, and labor. . .many locations become viable options for the production of food.

The article written by Philipp and Hank about the cost comparrison factors on vertical farming made complete sense to me. Indeed conventional building methods to erect vertical farms with concrete steel and wood, are too costly of a way to construct.
However if one was to find an alternative building solution, that would involve lower construction costs, it would make sense to investigate that option.

We have been building the same type of building envelope for many years and cannot change the most common denominator of the system "the labour". With labour costs as high as they are, and even climbing higher, it understandable that the cost of construction outways the benefits of the vertical farm.

We have been working on a solution to provide a vertical farm for the market for about 7 years, and are comming closer to the solution as each year passes.

Trying to feed 10 Billion people over by the year 2050 with abundant food and nutrients seems like a hard task, but it is possible to achieve.

Help us make a difference in the industry by joining us to cfreate a substainable future through vertical farming, either in the city or outside of it.

Cheers and take care.

Torsten Klasen
lexCoat International Inc.

is the way of the future, but that doesn't mean it has to be inside skyscrapers, in the middle of cities. Vertical simply means growing UP, instead of OUT, and if we can't figure out how to do that effectively, we're going to have one hell of a time trying to feed 10 billion people. We're already not very good at feeding 6 billion.

An effective vertical farm will have to not only bring construction costs down, but it will also have to master energy consumption and self-sustainable technologies.

Hydroponics and aeroponics provide amazing crop yields, compared with traditional farming, and I don't think it will be long until we begin seeing giant leaps and bounds in this industry.

In my humble opinion, farming done this way makes perfect sense...I found out more about it here...

Here is a scholarly document, with well-cited sources included, proving that vertical farming is economic:

http://www.verticalfarm.com/PDF/report2006/Economic Considerations.pdf

Vertical Farming, particularly in skyscrapers, is definitely not ECONOMICALLY feasable now (though it could be done). However, once one comprehends the statisitcs of our global situation (food safety, food availability, population increase, land availability, urban development, fuel costs, and on and on) it becomes clear that these paths will eventually meet with agricultural tech development at some point in the relatively near future - in 50 years, it may no longer be a question of profit, but simply a necessity, and we had better hope that the systems are developed and in place to meet the demands when the time comes. This will probably translate to something somewhere between a typical greenhouse, and a vertical farm skyscraper.

the biggest issue with using office building and having "green walls" is that there are stringent requirements for how much natural sunlight enters the building. Maybe in south-facing walls, there could be one or two low shelves, but no more than that. though I have to admit, working in an office with fresh air from plants would be very nice.

Thank you for some common sense! Vertical farming is really a joke proposal. It would require massive amounts of energy to build a vertical farm, and even the daily operation would use more energy than you would save from transporting food shorter distances. This means a vertical farm would generate large amount of net carbon and contribute to global warming. It would also be much less resilient in the face of energy shortages or peak oil. However, that's not to say that growing more food in urban areas isn't a good idea. Growing food on lawns and building community gardens are both great idea.

http://www.selfdestructivebastards.com/2009/12/vertical-farming.html

Thanks for the post, we will post your hydroponics system word press.com article. I will post for our customers to see your articles on your blog hydroponics systems

This article is lame. By similar analysis solar and wind generation of electricty is not cost effective either. So let's stop innovating, trying new ideas, encouraging people to think outside of the box and go back to business as usual, move along, nothing to see hear.

I know that's not what the authors intended to say but that is what you are saying. How many things in everyone's day to day life would exist today if it weren't for those who dreamed.

Not all countries with skyscrapers have readily accessible and fertile farm land like we do.

...someone took a critical look at vertical farming. As far as the link citied above, "proving" VF is economic: (http://www.verticalfarm.com/PD...6/Economic Considerations.pdf)

I followed the link and read the paper closely--first time I've seen real numbers supplied by VF proponents. Unfortunately, there's some big problems with the assumptions, and with the numbers.

First, the paper really isn't "scholarly"--it's a class project by Prof. Dickson Despommier's students, published on Despommier's website, not in a scientific journal and not peer-reviewed. It does have a lot of sources (some more reliable than others) and the students did appear to have worked hard on it. Here's what I think they missed:

1) In spite of leading off with the usual story that VF is a way to sustainably feed the world's starving millions, the paper is actually proposing a venture capital VF which will grow a single crop--gourmet lettuce--intended to be resold at a high profit margin.
2) They give construction costs for the shell alone as $25 million (21 stories, 10,000 sf footprint, 230,000 sf total). With equipment, cost is $83.7 million. NO mention of land cost, which in NYC will be significant. No one in NYC is going to donate real estate to a venture intended to make a profit for investors.
3) The students propose a "direct-to-consumer" sales model. Sounds good, except they expect the VF to produce 11,628,000 heads of lettuce (at what appears to 1# per head) per year. They give avg. gourmet lettuce consumption in NYC as 8 #/person/year. This would mean selling a head of lettuce directly to 1.5 million people, 8 times a year, and somehow doing this with a planned total workforce of 58. Even assuming their customers bought 1 head per week, that would be over 224,000 customers per week, or about 32,000 per day, or 4000 per hour.
4) The BIG problem: the energy that will be converted into edible plants is all artificial light, according to the paper, which will powered by a biogas/fuel cell cogeneration unit. The unit will cost $11 million, be fueled by waste biomass (including human and animal waste) generated by the people of NYC, and produce enough power to run a 4500 kW grow light system. The students calculate energy needs for the lights at 81,000 kWh/day--actually, 4500 kW times 24 hours is 108,000 kWh. They expect this to replace electricity costing $4.5 million/year if bought from the NYC grid.

Here's the kicker: because residential and public wastes "have no market value," they assume it is totally free--no labor and transportation costs for collection and handling. The waste will magically appear in the VF, where it will be free fuel to make electricity. If this was true, why not skip growing produce and just set up an electricity farm, making $4.5 million yearly profit on $11 million startup capital? And why isn't everybody doing this?

Answer: because it won't work. The students figure their cogeneration unit will make 32 cubic feet of 84% methane gas from 1 kg of waste. Taking their word for it, that's 840 BTUs of burnable gas per cubic foot times 32 equals 26,880 BTU/kg of waste. This is the equivalent of 7.9 kWh, essentially the same as the 8 kWh/kg they claim. BUT, they forget to decrease that by the efficiency of the gas to electricity conversion, which they cite as 40% (waste heat might be useful for other processes, but it won't power light bulbs). So actual electricity generated is 3.2 kWh/kg of waste.

This means the cogeneration unit will need about 1,000,000 kilograms of waste per month to power the lighting--1000 tonnes. That amount is not going to collect itself and show up at the building for free. Moreover, the amount of edible food with that amount of waste as byproduct is orders of magnitude greater than the food produced by the vertical farm. This means VF biomass power generation is parasitic on (non-VF) food production elsewhere, and is not self-sustaining--if you could use waste to produce enough surplus energy to produce more food, equal to the amount of food that the waste produced, you'd have a perpetual motion machine (or one of Jesus's miracles).

And, if the cogeneration concept spreads, biowaste will quickly become scarce and acquire market value, driving production costs higher. This might be a (very expensive) way to reduce landfilling in the short term, but it will no more feed the starving billions than Soylent Green will.
5) Finally, even with all the optimism and overlooked expenses, the students classify their project as a "high risk" investment with a rate of return slightly *lower* than very low risk government bonds. This hardly "proves" the economics. No wonder there have been no takers yet.

Set aside talk of profits and investment for a moment. 1.1 billion people are starving in the world right now, most living on less than $1 per day. That is WHY they are starving--for the moment, the world produces more than enough food calories (about 2800/person/day) to feed all 6.8 billion of us, it's just that 1/6th of the world can't afford to eat, while the rest of us eat too much. (All numbers from UN FAO)

Making food and food production more expensive means more people starve, which is exactly what happened a few years ago when biofuel diverted corn from people to cars and drove up the price.

With all respect, Biofule did not drive up the price of foods and it does not need to. Reference Alcohol can be a gas by David Blume. The oil company's were playing games to make sure they don't have any competition. That is an argument in it self.

What a great idea ! I can think of 10 ways to do this. Not suer any of them would fit in to our current so called capitalist structure and since that is the world we are in for now. I was doing some experimenting with tilapia fish farming in Hawaii. I would run the fish pond water through some hydroponic tomatoes. Worked pretty good. The tomato roots cleaned the water and the fish pond water feed the tomatoes. There are 2 things you need for farming ,heat and light. These buildings might have enough excess heat that could be used to heat the fish. As far as lighting goes, maybe , just maybe the new Full Spectrum LED's might work. Or when I was in college we were working on a project to use fiber optics to snake light down through buildings. With a collector on the roof. There are a lot of things if you think out side the box. I would love to get back into it if anyone wants to start a project again. If things keep falling apart we may need to rethink how we do things. I don't know many people who are happy working and really what are we getting out of it ? I think the capitalist model is dead. We need something that makes us all happy and makes the world a better place
Joe

Check out this vertical farming system operating in the UK and ready to spread worldwide now that J.F.K. Jr. is on their board and Time Mag named it in their Top 50 Innovations in 2009: http://bit.ly/6CXsIp

VertiCrop works, is profitable, and has zero food miles, uses less than 5% H2O and zero chemicals! Now who can argue with that?

I agree there are not going to be agricultural buildings that 20 stories tall, but some vertical farming will happen. One reason is that greenhouse-style agricultural uses 95% less water. Clean fresh water is a resource that we are running out of. Valcent Products, mentioned earlier, doesn't build massive buildings they specialize in small vegtables and leafy greens inside regular warehouse size buildings. This can be effective because you save money on transportation, use less water, and you won't need half as much pesticide. Furthermore, good farm land cost more like 10000 an acre unless you are buying over 50 acres, which most people can't afford. Secondly they make commercial pumps that cost almost nothing and move hundreds of gallons of water.

Its simply indoor hydroponics, people are doing that everywhere.

Hi All,

I do agree with the views of many that current urban vertical farm concept still in its infancy technological stage. Currently, it is not a very economical and productive options. We have not reach the economic of scale and achieve various conditions to make urban vertical farming a cheaper alternative.

As our human population progress and increases, we need to explore more urban farming alternatives. This means we need to ensure we have a holistic approach to our global food security crisis. Some suggestions are:

1. Urban farming.
2. Suburban farming.
3. Window farming.
4. Explore simple and cheaper alternative of urban vertical farming concept.

For option 4, we can consider retrofit existing deserted industrial and commercial buildings. The selected building design need to allow lot of natural light and ventilation coming in.

In fact, I have written some holistic approach and suggestions that maybe useful to this topic in the following blog post:

1. Vertical Farm Start-up Peer Learning Topic Request (Summary).

- Main Consideration Factors for Urban Vertical Farm Development Projects.

- http://jangworld.com/omnigens/?p=693

- This article summaries the main and their sub main points of a 3-part series on urban vertical farming issues.

- 1.Investment Cost Considerations and Concerns.

- http://jangworld.com/omnigens/?p=551

- 2. Business Operation Cost and Issues.

-http://jangworld.com/omnigens/?p=575

- 3. Critical Fundamentals for Urban Vertical Farming Success.

- http://jangworld.com/omnigens/?p=623


2. Urban Vertical Farm’s Start-up Solution

- Ideas to Make Urban Vertical Farms Start-up Concept Come True.

- http://jangworld.com/omnigens/?p=512

This article suggests some ways in address known urban vertical farming’s concerns

1. Huge investment on infrastructure.
2. Business operation cost.
3. Operation maintenance cost.
4. Concern for other forms of food security or shortage.


Best Regards,
James Ang
The omniGens Blog

http://omnigens.jangworld.com (Main)
http://omnigens.wordpress.com/

About James Ang

James Ang is a Gen Y Blogger (or Gen Y Pro blogger – stands for Professional Blogger) who blogs mainly on innovation, peer learning, personal development and well beings.

About The omniGenerations Blog’s Concept

The omniGenerations Blog (or The omniGens blog in short) is a peer learning community blog or a peer learning micro wiki blog [22] that focus on the holistic development of our lives. The omniGens Blog leverages on the collective wisdom of our proactive community in helping us to achieve simple work – life balance and happiness. Make Life Simple.

Excellent post: I've been wondering about this for quite a while, after seeing it in Popular Science (?) and a few articles online. It's really just not feasible - really cool, yes - but completely insane.

I think rooftop greenhouses for existing commercial buildings in the cities make sense. It could be a network of rooftops that go to a centralized market in the city.

Commercial Real Estate is declining in the US. they could make use of that vacant space to make real production.

I think the people saying this is not going to work really haven't done their research. They think of these farms like the empire state building but their not that shape. If they were rectangle, yes there would be a space problem, but they're not. The vertical farms are a wedge shape. There is one currently being build in Milwaukee WI. The water is recycled, solar energy, building heated by the sun and heat is stored under ground, and the food is actually Organic! I dont know about you but pesticides scare me.

@ Eric, above:
With respect, if you look at the posts above or at a similar thread on Scientific American's site ( http://www.scientificamerican....ical-farms ) I think you'll find VF skeptics have done their research, from sources beyond Dickson Despommier, and have done a lot of number-crunching as well. No one is saying plants can't be grown indoors and vertically, only that doing so can't solve the problems VF proponents claim VF will solve, and that VF can't sustainably replace flat farming, either outdoors or in.

The essence of farming is the conversion of "free" solar energy to edible biomass. Plants aren't very efficient at doing this (about 1-4% for the best "natural" plants, maybe 10% for bioengineered algae), but since we can't eat light or electricity, they're all we have. The amount of sunlight available to a VF has nothing to do with its height or shape--it's a function of the area of the land it sits on (its footprint). That is, a VF with a one-acre footprint has no more light energy available to grow crops that a one-acre field or a one-acre flat greenhouse, no matter how many floors it has, or how those floors are arranged. Technology and clever design can't solve these problems--they are the result of fundamental physics, basic geometry, and plant biochemistry.

Artificial lighting could substitute for sunlight, but the energy to make it has to come from somewhere. You can't grow new plants just using energy produced with waste from people and animals your VF feeds--this would be a perpetual motion machine (as pointed out above). You can't use solar cells, as they would have to cover a greater area of land than the total area of crops in your VF. You can't sustainably use fossil fuels. A working fusion reactor might do the trick. Problem is, we don't have one (other than the sun).

Of course, all this misses the real point, which cannot be made often enough: one sixth of the world's people are starving now. The world produces more than enough food to feed everyone (average of 2800/Cal/day/person). If a person thinks growing food in $500 million VFs will change that, they need to make a detailed argument (with number-crunching) for their position.

...I assume the Milwaukee VF Eric references is the one planned by Will Allen and Growing Power. Now, Will Allen seems like a really smart guy, whose organization is doing great work and bringing awareness to the lack of fresh food in the inner city, as well as promoting urban farming on waste ground. I wouldn't want to take anything away from what he's done and is planning to do. But the building he's planning isn't being built right now--according to a Milwaukee Journal-Sentinel article dated 29 April 2010 ( http://www.jsonline.com/news/m...77004.html ) Allen is "close to launching...a fund-raising campaign for the project." Given that the architect's concept for the building was clearly in the early stages of design, and given that the amount of money Allen needs to raise is "$7 to $10 million" there is simply no way the building is being built less than two months later.

More importantly, Allen's concept for the building refutes nothing VF skeptics have been saying. According to the article, it will be five stories with 23,000 sf for classrooms, kitchen, food storage, etc, and 15,000 sf of growing space under glass--48,000 sf total. That's an average of 9,600 sf per floor, but since the sketch makes it clear the lower floors are far bigger than the upper floors (the wedge shape Eric talks about) it looks like the building footprint will be about the same as the growing space: 15,000 sf (about 1/3 acre). So in that sense, the building is no more innovative than a flat greenhouse. Estimated construction costs are in line with the original post above--about $150-$200/ sf--as expected, much higher than building a conventional greenhouse.

The really big question is: can buildings like the one planned by Allen and Growing Power provide a sustainable, self-sufficient supply of food for dense urban areas? I don’t know that Allen is claiming it can, but that is certainly the claim of VF evangelist Dickson Despommier and his supporters. Unfortunately, the answer is clearly “no.” Here’s why:

While Despommier is fond of saying how many servings of lettuce or strawberries his VFs might theoretically produce, the only measure of food that counts if we’re talking about actually feeding people is calories. The reason a VF (or any other farm) can produce so much lettuce in such a short time is there’s very little food energy in the crop—like so many other fruits and vegetables, lettuce is mostly water. Without a calorie-dense staple, such as rice, wheat, field corn, etc, people starve.

But what if a building like the one Allen plans to build produces only high-yield, calorie-dense crops like field corn, and that growing indoors allows two crops per year? Even granting this best-case scenario, the yield won’t be more than 2.5 Calories/sf/day, or about 37,500 Calories/day total. Which sounds like a lot, except adults need on average 2000 Calories/day each, so the whole five-story, $10 million high-tech greenhouse feeds less than 20 people per day. Assuming the building lasts 100 years (three times longer than the average commercial building), construction costs alone will be over $5000 per person fed per year, with no consideration of farm labor, seed cost, building and equipment maintenance, interest on loans, etc. For a varied diet, with a lot more interesting (but much lower calorie) food than corn mush three times a day, the number of people fed will be far lower, and the costs far higher.

As a demonstration that people in the inner city can come together, shape their own destiny, and plan, fund-raise and build the first large indoor urban farm in the world, I’m all for Allen’s project. But even when built, the project will prove nothing regarding claims that VF can feed the starving billions of the world. I doubt Will Allen and Growing Power think that it does, or care. But that is the claim that people like Dickson Despommier make for VF, over and over again, and that is what many of us are skeptical about.

This makes sense in terms of replacing traditional agriculture considering the cost. I do think it is a great idea on a smaller scale to supplement food for certain communities.

With regard to the relative cost of land, this depends very much on how the various costs and externalities are valued and regulated. The biggest threat to the biosphere comes from agriculture and the amount of ecological space that we take up as a species. Land is a proxy for ecological space. If in order to survive and to develop a sustainable long term relationship between the biosphere and the economy we need to relinquish some of our grip on natural ecosystems and allow for significant re-wilding, urba food production might have a sigificant role to play. In this case, the 'cost' of agricultural land would rise astronomically relative to office space in the core. So this is really a question of economic and ecological priorities i.e politics. The bigger question is whether it would ever stack up energetically in terms of EROI. But we wo;t know until we try and the math might change with new technologies. Synthetic biology in particular might allow for significant 'trophic detachment'.

eh-hem... Apparently many posters here are not aware of, or choose to ignore, the fact that many "garden" or "salad" vegetables in your groceries stores are grown "indoors". Hothouses, greenhouses, whatever you want to cal them, are anything but "cheap farmland". growing indoors, and without soil (hydroponics) has too many advantages of dirt farming to do it any other way. Less water, fewer pest, better environment control, and never losing a crop to hail...

Tomatoes, lettuce, cucumbers, peppers, green onions... outside of the stuff you see at the farmers market, it's all pretty much grown in a building. Get used to it.

Regarding "cheap farmland", 4k to 5k for grain land, but the prime vegi growing land in the Imperial valley in SoCal can go for 10k an acre. And then you have to pay a small fortune to secure water rights. Then you have pest control issues, weather issues like frost, hail, heavy down pours, etc... then you have to deal with variable national market prices...

Locally grown on hothouse, stacked or not is not just the future, it's now.

Just a technical note, some of the best farm land you can buy in the country might cost $5,000 an acre, but for ease of math we'll say $4,356 an acre. An acre is 43,560 square feet, and therefore farm ground is $0.10 per square foot (roughly), making a sky scraper 2,000 times more expensive and 10 times less feasible than the article stated.

Regarding real estate cost, there's no question that real estate in cities is expensive. And yet, there are abandoned buildings that nobody wants at any price occupying some of that supposedly ultra-valuable land, so clearly a single astronomical square footage quotation doesn't tell the whole story. Yet another way of saving on land cost is to build, not a single-use agricultural building, but an integrated residential/agricultural or office/agricultural or commercial/agricultural building.

It is indisputable that providing artificial growing light would make it uneconomical to grow anything but marijuana, but I see no reason why natural sunlight cannot be provided. This fits in with the multiuse building concept, since providing natural light would favor the building's envelope as the ag location, leaving most of the interior volume available for other purposes.
Further, I think that energy saving hasn't been fully credited. It has been pointed out that transportation costs are a small fraction of the total energy cost of agriculture, but I have a strong suspicion that additional energy savings accrue. Obvious savings accrue in tilling and weeding, as well as harvesting.
Another saving is in the reduced use of pesticides and questionable fertilizing practices. There will be pressure to eliminate potentially toxic inputs due to the fact that the building's air will be shared by human occupants. Coincidentally, the greater control over inputs allowed by essentially indoor cultivation will reduce the need for pesticides. There will be pressure, both economic and sanitary, to limit artificial fertilizer inputs, but coincidentally the propinquity of organic waste generators (restaurants, homes) and farming will make composting - a logistical nightmare in conventional farming - a practical proposition for fertilizing commercial crops.
Market forces will favor mixed cropping, which will tend to mitigate problems caused by massive monoculture.
Subject to correction when there are hard numbers, I see genuine potential here, not just a pipe dream.

It's sad that everyone always cites Dickson Despommiers design as a reason to justify slamming efforts to bring production back home.... Our economies badly need it, and so does our health and our dear planet earth...Practice is born out of theory, which itself is born out of ideas....I concur that 100 million dollars construction cost is high, and not realistic.

For the past year I have been designing a system that takes all the good from Mr Despommiers concept, minus the ...astronomical costs to build and operate. The ExoFarm will need about 2% to 5% of his cited amounts to feed the same number of people, and operation costs are significantly less, perhaps as much as 80%. This new concept makes vertical farming feasible economically which means the idea went to theory, and now practice. We are based in Montreal, Canada and our first concept farm will be fully operational before end of 2012. You can contact me at This e-mail address is being protected from spambots. You need JavaScript enabled to view it '> This e-mail address is being protected from spambots. You need JavaScript enabled to view it if you would like more information or would like to be added on our list for press conferences and releases.

Khaled Majouji,
President, In.Genius Group