The Green Appeal of Vertical Farms

Will vertical farms feed the cities of the future?

Stepping into a vertical farm is like being transported into the middle of a sci-fi movie. These high-tech indoor farms grow food six meters in the air using a combination of hydroponics, artificial intelligence and LED lighting. Proponents of vertical farms say they’re an answer to doomsday predictions about the rising populations of cities and the ever-worsening global food crisis. Certainly, their ground-breaking use of technology and the massive investments made in the sector seem to support this. However, the number of failed startups littering the industry suggest that vertical farming is far from easy and perhaps not as promising as first presumed.

Vertical farms: the good and the not-so-good

The Good

  • 2. More Food, faster

    More food, faster: By growing food upwards rather than outwards vertical farms maximise land use. Plenty says that they can achieve yields of up to 350 times greater than outdoor fields. Also, by growing food in controlled, monitored environments vertical farms shave days off growing times to deliver crops more quickly.

  • 3. Taste and Nutrition

    High-tech vertical farm Plenty uses a combination of infrared cameras and sensors to monitor temperature, humidity, carbon dioxide levels and to record the plants’ growing phases in real time. This data helps their team of botanists to fine tune the plants’ environment and deliver tastier, healthier food.

  • 4. Food Miles

    Food miles are the distance produce travels from farm to table. Growing food within urban centres prolongs the shelf-life of produce as it goes straight from farm to shop. This also minimises transportation costs. In theory, this should make vertically farmed food much less expensive than its field-grown counterparts. Matt Barnard of Plenty says that, “30-45 percent of the final value at shelf is attributable to trucks and warehouses,” and ultimately, he hopes that these cost savings could help more people afford healthy, perishable food.

  • 5. Controlled Environments

    Field farmed food is at the mercy of unpredictable weather and it is vulnerable to pests. Vertical farms grow food in controlled environments, meaning that they aren’t subject to the ravages of the weather, or even the passing seasons. They can grow food risk-free year-round.

    Entering a vertical farm usually involves a complicated cleaning and sterilizing protocol, meaning that pests virtually don’t exist in a vertical farm (unless you count the ladybirds helping to keep Plenty’s crops pest-free). This means that crops aren’t treated with agrochemicals such as pesticides.

The Not-So-Good

  • 1. Energy use

    Vertical farms use LED lighting and climate control systems to create ideal growing conditions for their plants. While this tends to produce higher yields in less time, it is also associated with much higher energy demands than other methods of food production. Andrew Jenkins of Queens University Belfast says that, “lettuces grown in traditionally heated greenhouses in the U.K. need an estimated 250 kilowatt-hours of energy a year for every square meter of growing area. In comparison, lettuces grown in a purpose-built vertical farm need an estimated 3,500 kilowatt-hours a year for each square meter of growing area.” Plenty aims to reduce the energy demand of their farms by incorporating renewable energy sources such as solar.

  • 2. Variety of produce

    Most vertical farms currently in operation focus on growing leafy greens such as herbs, lettuce and spinach. These are the crops which have proven themselves to be profitable and scalable. However, the majority of calories on our tables comes from staple crops such as rice, wheat, soy and maize. Expert Lou Albright says that growing wheat indoors makes no sense. He calculated that if you grew wheat indoors under LED lights, just the electricity cost per loaf of bread made from that wheat would be $11 (a loaf of bread typically costs about $2.50). Similarly, growing larger fruits and vegetables in vertical farms, although possible, isn’t financially viable with the current technology.

  • 3. Greenhouse Gases

    Despite having a higher energy demand, vertical farms avoid most of the greenhouse gas emissions associated with outdoor farming techniques. However, the main polluters in the agricultural sector are the cattle, soy and oil palm industries of South America and Southeast Asia, which emit huge amounts of carbon dioxide in the clearing of forests to create agricultural land. At present, neither cattle, soy nor oil palms are good candidates for vertical or indoor farming. Neither are livestock farming and rice paddies, two other main contributors to greenhouse gases. While these practices continue, vertical farms will struggle to make a significant dent in our climate change problem.

  • 4. Attractive Alternatives

    The UN estimates that by 2050 68% of the global population will be living in urban areas. This prediction alone makes it apparent that the development of urban farming is crucial to feeding our future cities. Andrew Jenkins argues that farms in the form of greenhouses and communal gardens built on vacant flat roofs are a more realistic and energy efficient option. Although they produce lower yields, rooftop greenhouses need 70% less energy per square metre than vertical farms.

At present, vertical farms aren’t the answer to our population and food security problems. They also don’t appear to be the only promising indoor alternative to traditional farms. However, their potential for the future is apparent and supported by the massive amounts of funding these farms have received so far. In July 2017 Plenty raised $200 million in a Series B round of funding, while Aerofarms has raised $130 million to date. Investors include big names such as IKEA, SoftBank and Bezos Expeditions. Negotiating the pitfalls of the vertical farming industry is tricky, as explored in this article by Chris Michael of Bright Agrotech, and it will be interesting to see how existing and new farms respond to the challenges facing them.

3 Inspiring Vertical Farms

Based in New Jersey, USA, Aerofarms grows leafy greens in large trays, stacked six meters high in repurposed industrial buildings. They sell their produce under the Dream Greens brand and have a passion for creating locally grown, delicious produce. They say they their farms use 95% less water than field farmed-food and yields 390 times higher per square foot annually.

2. Plenty

This San Francisco-based farm grows crops on six-meter high vertical poles. Their roots are fed by a trickle of nutrient rich water and light is provided by LEDs. Plenty are currently looking for ways to expand the variety of crops grown by vertical farms and to incorporate renewable energy sources into their farms. Their aim is to build farms near major urban centres to make fresh produce more accessible for city-dwellers. Early in 2018 they announced their intention to build 300 indoor farms in or near major Chinese cities.

Freight Farms have a different focus to most other vertical farms. Their Leafy Green Machine (LGM) is a fully assembled, vertical hydroponic farming system built inside a shipping container. This farm-in-a-box grows greens in any climate and location, year-round. Each LGM includes a seedling growth area and 256 vertical crop columns, capable of growing 2-4 tons of produce per year. The LGM has been successfully used to create urban farms in cities like New York and to supplement existing outdoor farming activities.