What Is Vertical Farming?
Vertical farming is a greenhouse method of agriculture where commercially viable crops are cultivated inside multi-storey buildings in cities to simulate natural ecological systems. Since everything is ‘hydroponic’ in this practice, i.e., in mineral solutions, the problems of soil erosion, pesticide toxicity are not there. Dickson Despommier of Columbia University is the progenitor of this technique that will provide an answer to growing food requirements.
It is the practice of producing food and medicine in vertically stacked layers, vertically inclined surfaces and/or integrated in other structures (such as in a skyscraper, used warehouse, or shipping container). The modern ideas of vertical farming use indoor farming techniques and controlled-environment agriculture (CEA) technology, where all environmental factors can be controlled.
These facilities utilize artificial control of light, environmental control (humidity, temperature, gases…) and fertigation. Some vertical farms use techniques similar to greenhouses, where natural sunlight can be augmented with artificial lighting and metal reflectors.
There are a few main models for indoor agriculture that vertical farmers tend to choose from: hydroponics – in which plants are grown in a nutrient-rich basin of water – and aeroponics, where crops’ roots are periodically sprayed with mist containing water and nutrients. The latter uses less water overall, but comes with some greater technical challenges. There’s also aquaponics, which is slightly different, in that it involves breeding fish to help cultivate bacteria that’s used for plant nutrients, the key benefit of vertical farming is that it uses far less water.
One of the biggest names in vertical farming, AeroFarms in New Jersey, USA, has opened what they say is the world’s largest indoor vertical farm – with a total of 7,000 sq m (70,000 sq ft) floor space – and they’re hoping to produce tasty greens in massive quantities.
Ed Harwood is the inventor and agricultural expert who came up with the technology that has made this possible. He got the idea years ago while working for Cornell University, where aeroponic systems were being used to grow plants in a lab setting. Why, he wondered, was this approach not being used on a bigger scale?
“I kept asking, ‘how come’ – people said, ‘Oh, it would never make money, the sun is free, it’s expensive to add lights and everything else, it won’t happen’,” recalls Harwood.
But he wasn’t satisfied with that. After years of experimentation he came up with a system and nozzle design for spraying the aeroponic mist onto his plants’ roots. At AeroFarms, the roots grow through a fine cloth rather than soil. But the details of how he solved the key problem – keeping the nozzles clean over time – remain a trade secret.
“Every nozzle I purchased off the shelf had significant issues,” says Harwood. “I had to do something about it – it was just a cool moment of, I guess, serendipity.” But he’s not telling anyone how he did it.
AeroFarms is prioritising the cultivation of fast-growing salad veg and greens. Harwood believes there is a demand for such produce grown locally in big facilities like theirs that could one day be a feature of city suburbs. And he also promises the guaranteed crunchiness and freshness that consumers want.
Harwood is firm in his belief that the business he and his colleagues have put together can be profitable. But there are still those who remain sceptical.
Michael Hamm, a professor of sustainable agriculture at Michigan State University, is one of them. He points out that vertical farms depend on constant supplies of electricity, much of which will come from fossil fuel sources.
“Why waste that energy to produce a whole lettuce, when you can get light from the sun?” he says. And he points out that it just doesn’t make economic sense to grow some crops this way: “At 10 cents a kilowatt hour, the amount of energy it would take to produce wheat would [translate to] something like $11 for a loaf of bread.”
He does acknowledge a few of the benefits, though. If the indoor systems are well-maintained, then the technology should in theory allow for reproducible results with every harvest – you’ll likely get the same quality of crops every time. Plus, while it costs a lot of money to set up a vertical farm in the first instance, it’s potentially a more attractive option to people getting into the agriculture business for the first time – they won’t need to spend years learning how to contend with the vagaries of the sun and seasons. For that, there’s no substitute yet for experience.
With the development of vertical farming technologies, and the likely fall in cost associated with them in coming years, some are betting that all kinds of people will want to start growing their own greens – even at home. There’s been a spike in home beer brewing – might we see a spike in farming at home, too?
Neofarms is one start-up based in Germany and Italy that is anticipating this. Its founders, Henrik Jobczyk and Maximillian Richter, have developed a prototype vertical farm about the size of a household fridge-freezer.
“We designed it in standard kitchen closet sizes,” explains Jobczyk, who adds that their plan is to make the device available as an integrated or standalone design, depending on the customer’s preferences.
People who choose to grow their salad veg at home will pay about two euros (£1.71/2.13) per week in energy costs with this system for the privilege, the pair calculate. And they would also have to keep the Neofarms device clean and constantly topped up with water. But in exchange they will have the freshest produce possible.
“With the plants growing in the system, you know about the conditions they were raised in – that gives you control and knowledge,” says Jobczyk. “But also it’s the freshness; one of the biggest problems with fresh veg – especially the greens – is the field to fork time, the time between harvest and consumption.”
Future supermarkets, though, might be filled with miniature vertical farms of their own
If you pick the plants yourself and eat them straightaway, you might enjoy a richer wealth of vitamins and other nutrients – which can be lost during packaging and transportation. Many consumers already grow their herbs on a window box, but that is a low-cost and low-maintenance activity. It remains to be seen whether the same people would be interested in making the conceptual leap that comes with bringing a mini vertical farm into their own kitchen.
Jobczyk and Richter will have to wait to find out – they’re planning more testing of their device later this year, with a public launch potentially following sometime after that.
Ed Harwood, for one, thinks vertical farming technologies might help to bring agriculture closer to the consumer. But he also sticks by his belief that farming on giant scales is here to stay.
“Irrespective of the number of recalls, I think we’ve improved food safety over all, we’re feeding more people with fewer resources,” he says.
One of the downsides of this is that children have to be introduced to the idea that their food is grown somewhere – it doesn’t come from the supermarket, but a field or factory. Future supermarkets, though, might be filled with miniature vertical farms of their own.
“For the child who says their food comes from the grocery store,” says Harwood, “they might one day be right.”