Vertical farming

Vertical farming is the practice of growing crops in vertically stacked layers.

The modern concept of vertical farming was proposed in 1999 by Dickson Despommier, professor of Public and Environmental Health at Columbia University.

The main advantage of utilizing vertical farming technologies is the increased crop yield that comes with a smaller unit area of land requirement.

Vertical farming technologies face economic challenges with large start-up costs compared to traditional farms. They cannot grow all types of crops but can be cost-effective for high value products such as salad vegetables.

Types

The term "vertical farming" was coined by Gilbert Ellis Bailey in 1915 in his book Vertical Farming. His use of the term differs from the current meaning—he wrote about farming with a special interest in soil origin, its nutrient content and the view of plant life as "vertical" life forms, specifically relating to their underground root structures.

Mixed-use skyscrapers

Mixed-use skyscrapers were proposed and built by architect Ken Yeang. Yeang proposes that instead of hermetically sealed mass-produced agriculture, plant life should be cultivated within open air, mixed-use skyscrapers for climate control and consumption. This version of vertical farming is based upon personal or community use rather than the wholesale production and distribution that aspires to feed an entire city.

Despommier's skyscrapers

Ecologist Dickson Despommier argues that vertical farming is legitimate for environmental reasons. He claims that the cultivation of plant life within skyscrapers will require less embodied energy and produce less pollution than some methods of producing plant life on natural landscapes. By shifting to vertical farms, Despommier believes that farmland will return to its natural state (i.e. forests), which would help reverse the impacts of climate change. He moreover claims that natural landscapes are too toxic for natural agricultural production. Vertical farming would remove some of the parasitic risks associated with farming.

Despommier's concept of the vertical farm emerged in 1999 at Columbia University. It promotes the mass cultivation of plant life for commercial purposes in skyscrapers.

Stackable shipping containers

Several companies have developed stacking recycled shipping containers in urban settings. The shipping containers serve as standardized, modular environmental chambers for growing. By stacking the shipping containers, higher density in terms of produce yield/square foot is possible. But, the stacked containers pose the challenge of how to effectively and affordably access the stacked levels. Brighterside Consulting created a complete off-grid container system.

Freight Farms produces the "Greenery" that is a complete farm-to-table system outfitted with vertical hydroponics, LED lighting and intuitive climate controls built within a 12m × 2.4m shipping container.

TerraFarms offer a system of 40 foot shipping containers, which include computer vision integrated with an artificial neural network to monitor the plants;

In abandoned mine shafts

Vertical farming in abandoned mine shafts is termed "deep farming", and is proposed to take advantage of consistent underground temperatures and locations near or in urban areas. It would also be able to use nearby groundwater, thereby reducing the cost of providing water to the farm.

Technology

Lighting can be natural or via LEDs. As of 2018 commercial LEDs were about 28% efficient,

History

One of the earliest drawings of a tall building that cultivates food was published in Life Magazine in 2009.

Hydroponicum

Early architectural proposals that contribute to VF include Le Corbusier's Immeubles-Villas (1922) and SITE's Highrise of Homes (1972).

The Armenian tower hydroponicums are the first built examples of a vertical farm, and are documented in Sholto Douglas' Hydroponics: The Bengal System, first published in 1951 with data from the then-East Pakistan, today's Bangladesh, and the Indian state of West Bengal.

Later precursors that have been published, or built, are Ken Yeang's Bioclimatic Skyscraper (Menara Mesiniaga, built 1992); MVRDV's PigCity, 2000; MVRDV's Meta City/ Datatown (1998–2000); Pich-Aguilera's Garden Towers (2001).

Ken Yeang is perhaps the most widely known architect who has promoted the idea of the 'mixed-use' Bioclimatic Skyscraper which combines living units and food production.

Vertical farm

Dickson Despommier is a professor of environmental health sciences and microbiology. He reopened the topic of VF in 1999 with graduate students in a medical ecology class. He speculated that a 30-floor farm on one city block could provide food for 50,000 people including vegetables, fruit, eggs and meat, explaining that hydroponic crops could be grown on upper floors; while the lower floors would be suited for chickens and fish that eat plant waste.

Although many of Despommier's suggestions have been challenged from an environmental science and engineering point of view, Despommier successfully popularized his assertion that food production can be transformed. Critics claimed that the additional energy needed for artificial lighting, heating and other operations would outweigh the benefit of the building's close proximity to the areas of consumption.

Despommier originally challenged his class to feed the entire population of Manhattan (about 2,000,000 people) using only 5 hectares (13 acres) of rooftop gardens. The class calculated that rooftop gardening methods could feed only two percent of the population. Unsatisfied with the results, Despommier made an off-the-cuff suggestion of growing plants indoors, vertically. By 2001 the first outline of a vertical farm was introduced. In an interview Despommier described how vertical farms would function:

Each floor will have its own watering and nutrient monitoring systems. There will be sensors for every single plant that tracks how much and what kinds of nutrients the plant has absorbed. You'll even have systems to monitor plant diseases by employing DNA chip technologies that detect the presence of plant pathogens by simply sampling the air and using snippets from various viral and bacterial infections. It's very easy to do. Moreover, a gas chromatograph will tell us when to pick the plant by analyzing which flavenoids the produce contains. These flavonoids are what gives the food the flavors you're so fond of, particularly for more aromatic produce like tomatoes and peppers. These are all right-off-the-shelf technologies. The ability to construct a vertical farm exists now. We don't have to make anything new.

Architectural designs were independently produced by designers Chris Jacobs, Andrew Kranis and Gordon Graff.

Mass media attention began with an article written in New York magazine,

In 2011, the Plant in Chicago was building an anaerobic digester into the building. This will allow the farm to operate off the energy grid. Moreover, the anaerobic digester will be recycling waste from nearby businesses that would otherwise go into landfills.

In 2013, the Association for Vertical Farming was founded in Munich, Germany.

As of 2014, Vertical Fresh Farms was operating in Buffalo, New York, specializing in salad greens, herbs and sprouts.

Kyoto-based Nuvege (pronounced "new veggie") operates a windowless farm. Its LED lighting is tuned to service two types of chlorophyll, one preferring red light and the other blue. Nuvege produces 6 million lettuce heads a year.

The US Defense Advanced Research Projects Agency (DARPA) operates an 18-story project that produces genetically modified plants that make proteins useful in vaccines.

Problems

Economics

Vertical farms require substantial start-up funding and some start-up companies have not been able to active a profit before going bankrupt.

Similarly, if power needs are met by fossil fuels, the environmental effect may be a net loss;

The initial building costs would exceed $100 million, for a 60 hectare vertical farm.

The developers of the TerraFarm system produced from second hand, 40 foot shipping containers claimed that their system "has achieved cost parity with traditional, outdoor farming".

Energy use

During the growing season, the sun shines on a vertical surface at an extreme angle such that much less light is available to crops than when they are planted on flat land. Therefore, supplemental light would be required. Bruce Bugbee claimed that the power demands of vertical farming would be uncompetitive with traditional farms using only natural light.

As "The Vertical Farm" proposes a controlled environment, heating and cooling costs will resemble those of any other tower. Plumbing and elevator systems are necessary to distribute nutrients and water. In the northern continental United States, fossil fuel heating cost can be over $200,000 per hectare.

Jones Food Company in Gloucestershire, England opened a farm in 2024 with 14,500 square metres (156,000 sq ft) of growing space, powered only by renewable electricity.

Pollution

Depending on the method of electricity generation used, greenhouse produce can create more greenhouse gases than field produce,

Greenhouses commonly supplement CO2 levels to three–four times the atmospheric rate. This increase in CO2 increases photosynthesis rates by 50%, contributing to higher yields.

Greenhouse growers commonly exploit photoperiodism in plants to control whether the plants are in a vegetative or reproductive stage. As part of this control, the lights stay on past sunset and before sunrise or periodically throughout the night. Single story greenhouses have attracted criticism over light pollution.

Hydroponic greenhouses regularly change the water, producing water containing fertilizers and pesticides that must be disposed of. The most common method of spreading the effluent over neighbouring farmland or wetlands would be more difficult for an urban vertical farm.

Advantages

Many of VF's potential benefits are obtained from scaling up hydroponic or aeroponic growing methods.

A 2018 study estimated that the value of four ecosystem services provided by existing vegetation in urban areas was on the order of $33 billion annually. The study's quantitative framework projected annual food production of 100–180 million tonnes, energy savings ranging from 14 to 15 billion kilowatt hours, nitrogen sequestration between 100,000 and 170,000 tonnes and stormwater runoff reductions between 45 and 57 billion cubic meters annually. Food production, nitrogen fixation, energy savings, pollination, climate regulation, soil formation and biological pest control could be worth as much as $80–160 billion annually.

Reduced need for farmland

It is estimated that by the year 2050, the world's population will increase by 3 billion people and close to 80% will live in urban areas.

Increased crop production

Unlike traditional farming in non-tropical areas, indoor farming can produce crops year-round. All-season farming multiplies the productivity of the farmed surface by a factor of 4 to 6 depending on the crop. With crops such as strawberries, the factor may be as high as 30.

Furthermore, as the crops would be consumed where they are grown, long-distance transport with its accompanying time delays, should reduce spoilage, infestation and energy needs. Globally some 30% of harvested crops are wasted due to spoilage and infestation, though this number is much lower in developed nations.

Despommier suggests that once dwarf versions of crops (e.g. dwarf wheat which is smaller in size but richer in nutrients

Weather disruption

Crops grown in traditional outdoor farming depend on supportive weather, and suffer from undesirable temperatures rain, monsoon, hailstorm, tornadoe, flooding, wildfires and drought.

VF productivity is mostly independent of weather, although earthquakes and tornadoes still pose threats.

The issue of adverse weather conditions is especially relevant for arctic and sub-arctic areas like Alaska and northern Canada where traditional farming is largely impossible. Food insecurity has been a long-standing problem in remote northern communities where fresh produce has to be shipped large distances resulting in high costs and poor nutrition.

Conservation

Up to 20 units of outdoor farmland per unit of VF could return to its natural state,

Vertical farming would thus reduce the amount of farmland, thus saving many natural resources.

Resource scarcity

The scarcity of fertilizer components like phosphorus

Mass extinction

Withdrawing human activity from large areas of the Earth's land surface may be necessary to address anthropogenic mass extinctions.

Traditional agriculture disrupts wild populations and may be unethical given a viable alternative. One study showed that wood mouse populations dropped from 25 per hectare to 5 per hectare after harvest, estimating 10 animals killed per hectare each year with conventional farming.

Human health

Traditional farming is a hazardous occupation that often affects the health of farmers. Such risks include: exposure to infectious agents such as malaria and schistosomes, as well as soil-borne microbes, exposure to toxic pesticides and fungicides, confrontations with wildlife such as venomous snakes, and injuries that can occur when using large industrial farming equipment. VF reduces some of these risks.

Poverty and culture

Food insecurity is one of the primary factors leading to absolute poverty. Constructing farms will allow continued growth of culturally significant food items without sacrificing sustainability or basic needs, which can be significant to the recovery of a society from poverty.

Urban growth

Vertical farming, used in conjunction with other technologies and socioeconomic practices, could allow cities to expand while remaining substantially self-sufficient in food. This would allow large urban centers to grow without food constraints.

Energy sustainability

Vertical farms could exploit methane digesters to generate energy. Methane digesters could be built on site to transform the organic waste generated at the farm into biogas that is generally composed of 65% methane along with other gases. This biogas could then be burned to generate electricity for the greenhouse.

Technologies and devices

Vertical farming relies on the use of various physical methods to become effective. Combining these technologies and devices in an integrated whole is necessary to make Vertical Farming a reality. Various methods are proposed and under research. The most common technologies suggested are:

Plans

Developers and local governments in multiple cities have expressed interest in establishing a vertical farm: Incheon (South Korea), Abu Dhabi (United Arab Emirates), Dongtan (China),

In 2009, the world's first pilot production system was installed at Paignton Zoo Environmental Park in the United Kingdom. The project showcased vertical farming and provided a physical base to conduct research into sustainable urban food production. The produce is used to feed the zoo's animals while the project enables evaluation of the systems and provides an educational resource to advocate for change in unsustainable land use practices that impact upon global biodiversity and ecosystem services,

In 2010 the Green Zionist Alliance proposed a resolution at the 36th World Zionist Congress calling on Keren Kayemet L'Yisrael (Jewish National Fund in Israel) to develop vertical farms in Israel.

In 2012 the world's first commercial vertical farm was opened in Singapore, developed by Sky Greens Farms, and is three stories high.