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: Sustainable Design Update
Check out this very cool video of an advocate for vertical farming on the Colbert Report.
Via: AIDG Blog