Vertical Farming
Vertical Farm
I have been asked several times lately what I think of vertical farming – the proposed practice where crops are grown in skyscrapers. The idea is being pushed by academics and enthusiasts.
My big doubt about vertical farming is based on the economics of building a superstructure with sufficient structural capacity to hold crops, water, soil (in the non-hydroponic proposals) humans and machines. Plus the live loads associated with rain, snow and wind. The structure would have to be at least as robust as what we currently build for offices and the infrastructure would be just about as expensive as any other building. So, based on current costs for construction, the cost of a vertical farm could be about $100.00 per square foot.
The cost of Georgia farm land is $2,074 per acre, average (University of Georgia Study), which is about 5 cents per square foot. This gives the Georgia farm a serious advantage. The rent on a $100.00 per square foot structure is about $21.00 per square foot per year, so space on a vertical farm might go for $10.00 = $21.00 per square foot. Corn brings in about $259.00 per acre ( www.profitablefarming.com) or about 7/10 of one cent per square foot. And corn is considered a profitable crop!
I can’t see the economics of vertical farming working out.
Check out this very cool video of an advocate for vertical farming on the Colbert Report.
Via: AIDG Blog
August 15th, 2008 at 1:58 pm
Are you making the assumption that they would only build this tower only to grow crops? I think what would actually happen is that it would still be an office tower with crops on the outside. Which would be an added source of income. And you would save money on transport of the food.
August 15th, 2008 at 2:40 pm
Great Idea!
I hadn’t thought of a “mixed use” building with people and plants. It would still have square footage devoted to plants, and that would add cost, but the aesthetic benefit and the close source of food might tip the balance a bit more toward the green tower idea.
I really like the idea of having lunch on the terrace in an organic garden 700 feet above the street.
Extremely Locavoracious!
March 9th, 2009 at 10:19 pm
Corn wouldn’t be grown in these, as the writer explains. What would be grown are the high value cash crops shown above. Further, there would be at least 4 crops per year per floor, such as lettuce, strawberries, etc. FYI, an acre of strawberries in a vertical farm yields as much as 30 acres of land. Good strawberry land goes for over $20k per acre. At a 30 time yield, this probably justifies the additional costs of the infrastructure.
March 14th, 2009 at 5:31 pm
Paul-
Hmmm – Any data on strawberry crop yields in vertical farms? I have heard a lot of numbers but haven’t yet been connected with a peer reviewed study. When we looked into the possibility of multiple crops per year using a treadle pump there were rarely 4 crops per year on all the land. Instead there were 4 crops per year but some overlapped with others on different parts of the farm.
Strawberry growth rate is a function of the number of hours of sunlight (along with many other things), so having plants shade other plants in a vertical garden may not permit optimal growth.
I’d really like to get my hands on a good study of vertical gardening. I’m sure there is something out there and if anyone has a link, please submit it to me. I’d like to pursue this topic in future posts.
jsbarrie
June 23rd, 2009 at 3:41 am
I only became introduced to vertical farming about a week ago and immediately thought about the mixed use concept, as the structures would presumably already be heated or cooled, space would be available and there would be asthetic values if the buildings also contained humans.
As an avid gardener I also thought that it would be high value crops like strawberries, herbs, shallots, lettuce, spinach etc. that would work well. The vision of strawberries with actual taste being available locally in winter gets me going. Generally, the best tasting veg and fruit ships ong distance poorly so they’re suited for the local market.
I’m also interested in learning if there’s any realistic, valid data on either existing vertical farm projects or realistic cost/benefit analysis out there.
August 27th, 2009 at 12:42 am
Paul – how did you determine that the rent per square foot on a building with construction costs of $100/sf would be $21/sf? That’s a capitalization rate of 21% – more than double the current national average for commercial office space (9.11%). So really, you should be talking more like $9/square foot for rent, depending on the market. Still a lot more than land in rural Georgia, but let’s not exaggerate.
September 16th, 2009 at 6:56 pm
I agree with Max E, plus you have to add the costs of transportation to the calculation, if we get cap & trade, it will become even more expensive to bring in fruits from far away.