A recent Economist article asks the question of vertical farming, “Does it really stack up?” In theory, it’s a win-win-win concept for the environment, feeding growing urban populations locally, and increasing space for agriculture without more land use. But the reality is that vertical farming is costly energy-wise due to the need for artificial lighting and insufficient space for renewable energy installations on skyscrapers. While many designs exist, no large scale vertical farm has been built yet. However, Will Allen’s Growing Power did receive approval this year from the Milwaukee city planning commission to build a five story greenhouse, perhaps marking a step toward the fruition of the first vertical farm.
A major argument for this concept is that not only will these vertical landscapes curb greenhouse gas emissions by eliminating the need for crop transport, but food spoiling – which comes along with the business-as-usual of hauling food over long distances — will cease to be a problem, as the food is both at the source and right at the hands of the consumer. Most designs propose that plants be grown hydroponically, cancelling out soil erosion issues and significantly decreasing water usage in comparison with conventional farming techniques. The standardized interior environment also allows for a year-round growing season.
Due to the nature of a vertical farm being indoors, the nutrient content, temperature, humidity, air flow and lighting can all be regulated. In this controlled setting, plants can be grown with little use of herbicides and pesticides, according to Columbia University’s Dickson Despommier, the so-called “father of vertical farms” and author of The Vertical Farm. Hear Despommier discuss vertical farming in this video:
Artificial light poses a big obstacle for vertical farms becoming an economically viable food source. Although such glass towers would provide some natural light to the plants, there would still be the need for artificial light. Otherwise crop production would be uneven, with those crops closest to windows receiving more sunlight. Peter Head, global leader of planning and sustainable development at the British engineering firm Arup explains to The Economist, “Light has to be very tightly controlled to get uniform production of very high-quality food.” The price of powering artificial light is costly, weakening the case that vertical farms will be energy savers and curb emissions. Head claims vertical farming proponents will need to figure out how to integrate renewable energy into the design in an affordable way in order for this idea to be feasible on a widespread scale.
In the meantime, companies are coming up with innovative compromises. Valcent, a vertical farming firm, has created the VertiCrop system which guarantees plants take in even sunlight and air flow via hydroponic, vertically stacked trays on moving rails. While they have a prototype, this system has only been designed for single story greenhouses where plants receive light from above as well from the sides and so may not be suitable for vertical farming.
Dr. Ted Caplow, environmental engineer and founder of New York Sun Works, advocates the “vertically integrated greenhouse,” a design that incorporates rotating crop production along the perimeters of buildings and offices within two sheets of glass. This system provides enough natural light to the plants and performs as passive climate control. Head makes note that urban farming on building rooftops is a more immediate solution that utilizes space already available instead of starting from scratch. The Economist concludes of this intermediary proposal, “it is much less glamorous than the grand vision of crops being produced in soaring green towers of glass. But, for the time being, this more down-to-earth approach is much more realistic than the sci-fi dream of fields in the sky.”
See what these four architects came up in this video with when asked by The Economist to explain their vertical farm designs:
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