When Dickson Despommier first developed the idea of growing crops several stories into the sky using hydroponic systems in 1999, people either thought he was a “half-baked” fringe scientist or a post-modern genius ahead of his time. Now more than a decade later, it may still be too early to tell. But the idea of a “vertical farm” offers too many tantalizing possibilities for future food production to be ignored.
At the centre of the “vertical farm” idea, is the notion of filling the floors of a vertical structure with fields and orchards using hydroponics. Hydroponics does not require any soil and instead suspends the plants in mineral rich water, thus reducing necessary inputs of freshwater sources. Clever recycling techniques would ensure that each vertical farm is a closed-loop system – all waste that is generated would remain in the building to be reused for another process. For instance, water that plants naturally transpire through photo-synthesis could be reused for the hydroponic systems.
These same processes have been used in greenhouses for years. The vertical farm takes the idea of a greenhouse, and stacks several of them on top of each other to form a skyscraper.
One of the biggest selling features of the vertical farm is that it can be located right in an urban centre. No longer will food have to be shipped in from faraway places, thus emitting high amounts of CO2 in the process; residents can enjoy food made right in their own city. And since crops can be produced in these vertical greenhouses year-round, residents don’t have to worry about seasonal effects on crop production.
In a global sense, vertical farms seem like an effective solution to food insecurity of the future. It is projected that the world population will grow to 9.1 billion in 2050, and that feeding all those people would require increasing food production by 70%. Unfortunately, the world is running out of “horizontal” farmland to grow on, and past farming practices have seriously degraded the farmland we do have. Vertical farming would therefore go a long way in ensuring the world has enough food four decades from now.
However, the vertical farm still has its “kinks” to be worked out.
The biggest problem is ensuring that the plants in the vertical farm receive an even distribution of light. For instance, if vertical farms exclusively used natural light, plants would grow unevenly since plants located near the outside would receive more light than plants located near the centre.
Thus it seems like artificial light would have to be utilized in order to ensure that plants receive enough light to grow. Unfortunately, this is where costs for vertical farms skyrocket, since providing enough light for several stories of orchards would cost some serious dough.
Although incorporating renewable energy sources such as solar panels or wind energy could alleviate some of these costs, they would still likely not produce enough energy year round to make the crops economically viable. But most recently, a graduate student at the University of Waterloo, Gordon Graff, has proposed the use of hydroponic systems that incorporate a “drum system” to ensure higher yielding, more efficient crops. His proposal (which was the focus of his thesis) even provides an economic breakdown of all the costs associated with his new design for the vertical farm. Graff’s work looks so promising that one expert claims that “the vertical farm is no longer just pie in the sky.”
With the rate that technology is progressing, I wouldn’t be surprised if we saw some vertical farms emerging in places like China or the UAE within the next decade.
What do you think, though? Will vertical farms solve the world’s impending food crisis? Or are they merely just another “pie in the sky”?