Green Upgrader has an interesting analysis of the sustainability of vertical farms. A vertical farm is kind of like a big tall building where each floor is a field or paddock rather than office space. Check out this picture:
Obviously by stacking your farm fields one on top of another you save space that might otherwise be used to grow forests or house people. It makes it much easier to put farms and food production systems in cities and towns close to where people will be eating the food, thus reducing carbon emissions and food miles.
And the article suggests that vertical farms have the potential at least to use less water, less fertilizer and fewer pesticides. They also have the potential to be enclosed units where contaminants can’t just wash away on the neighbouring land.
To me the big question is (and Green UpGrader poses this question too) how much energy needs to go into a vertical farm to make it work? The benefits of normal horizontal farms are that you don’t need to construct them out of steel girders, and once they are up and running they are mostly powered by sunlight (to make all the veges, trees and grasses grow). A vertical farm would either need an alternative energy source to sunlight to power it or some very clever design to get sun into all its nooks and crannies.
It’s potentially a clever idea but I am fairly convinced that it might just be easier, especially here in New Zealand, to use the farming space we already have more efficiently by promoting more diverse organic and local farming that has been shown to be more productive than large scale monoculture farming. Sometimes we don’t need to invent new solutions, we just need to actually use the ones we already have available to us.
Photo Credit: Vertical Farm