5 Headlines about Vertical Farming

Few fields in farming have generated as much heated debate as vertical farming (VF). The Vertical Farming market is expected to reach $7.3 Billion by 2025, from $2.9 Billion in 2020, even though this form of farming was almost unknown a decade ago. VF is literally turning conventional farming on its head, and comes a host of media-hyped headlines, but for investors no profits so far. This article attempts to critically examine the huge potential and where the pitfalls have been so far.

While the phrase ‘vertical farming’ makes for great clickbait due to its modern and unique perception, indoor farming has been around for decades. Using the phrase ‘controlled environment ag (CEA)’ captures both vertical and horizontal farming, such as greenhouses. These were one of the first methods farmers used to protect their crops from weather all year round (you might even have your own!), however the standard greenhouse wasn’t designed to withstand the range of climate variations which limit plant growth. The variations you experience while driving your car in the rain, when windows become foggy on the inside shows the complexity of adjusting both temperature and ventilation together. In agriculture, climate variations can cause a loss of flavor or even a reduction in nutritional value. To solve this issue, scientists began creating more optimal circumstances for indoor plant growth regardless of the weather.

Technological advances, including hydroponics and artificial lighting were introduced into greenhouses for this reason. LED lighting has proven to be the most important advance in the indoor farming movement, due to its lower cost, lower heat emission and lower electricity-consumption. LED lights are also ‘tuned’ to the optimal wavelengths for photosynthesis to enhance plant growth. These innovations paved the way for vertical farming.

Vertical farming offers three tremendous promises over conventional farming.

1)   Produce food within major population centers, minimizing ‘food miles’

2)   Eliminate the need for chemical pest and weed control

3)   Reduce water usage by more than 90%.

These alone should make us all exciting but how realistic are the claims surrounding this method of plant growth?

Headline #1: Vertical farms will feed the world

Feeding the world ‘vertically’ at today’s costs would be astronomical. The fixed costs alone for acquiring a 30-storey towers such as those proposed in places like Manhattan at full cost would leave you little change from $100m. Even a repurposed shipping container comes with the price tag of $85,000 ($450-$750 per square foot), compared to a mere $3000 of leasing an acre of farmland on not inexpensive land in Monterey County, CA for a year.

For established vertical farms these costs have already been invested, with the backing of some of the biggest names in tech, so not usually included in the costs of production. Plenty and AeroFarms, for example, have received upwards of $200m in funding to date, from investors such as Amazon’s Jeff Bezos. Informed investors are evidently excited about this agricultural endeavor, but to date, only 27% of vertical farms have been profitable.

At a consumer level, the just-picked freshness of the heads of lettuce that Green Line Growers offers comes at double the price of typical organic store-bought lettuce. Kale sold in Walmart costs $1.33 per pound, compared to $4.99 per pound in Whole Foods, which might hardly be considered a price jump considering that kale grown at AeroFarms costs a whopping $14.18 per pound.

The biggest costs in vertical farming are primarily the capital expenditure to build, yield, labor/automation, freight costs and energy. When comparing vertical, horizontal, and open field farming, the production cost of vertical loses out in most scenarios. “Emotional” driver’s retailer’s point to include buying local, alignment with consumers sustainability goals, freshness, and that it is much easier to manage with 1 - 2 days of lead time

Professor Emeritus at Cornell, Dr. Louis Albright, famously calculates that growing wheat in a vertical farm would generate 20 cents per square foot in annual income and growers would need to charge $24 per loaf of bread just to cover the power bills. And while vertical farms have yet to claim an interest in the grain industry, these figures show that further advancements will be needed if vertical farms want to fill more than the salad bowls of the affluent world.

Headline #2: Vertical Farms can grow all the same food products as conventional farms

This is technically true, but not necessarily feasible. Leafy greens, such as lettuce and kale, are the most common crops envisioned in many vertical farming plans. This challenge is growing calories and protein rich foods. Winter annual plants which thrive in indoor farms tend to be high in vitamins but very low in calories and protein. To grow oil seeds, soy, cotton, canola etc. you would need to completely re-imagine the indoor approach. Considering calories and protein production per acre, indoor spaces aren’t very productive, but by design or happenstance, suit western diets where calorie restriction with vitamin rich foods could be considered a good thing.

Reports by the food media are replete with reports of salad greens being grown successfully indoors under artificial light, but growing fruit vertically will require considerable energy and possibly extravagant quantities of energy to support the artificial lighting. Nutrient-dense grains or fruits come from plants with higher light requirements per weight of harvested product than plants like lettuce from which we eat only leaves or stems. And the higher the yield desired, the more supplemental light and nutrients required. Grain crops also require a large amount of the macronutrients Nitrogen (N), Phosphorous (P), Potassium (K) and micronutrients, whereas these are needed in much smaller amounts growing foliage plants.

Crops also need wind to develop tall, strong stalks, preparing them for carrying heavy loads before harvest. Indoor farms aren’t suited for this, so focus on growing greens. Genetic modification such as GMO’s or CRISPR offer the opportunity to create genetics that will grow more efficiently (think of growing giant grains of wheat with no stalk). The potential to produce such crops may take some time yet to develop.

Headline #3: Vertical farms will reduce the environmental impacts of agriculture

Vertical farms win here through a huge reduction in water levels needed. Agriculture globally accounts for 70% of freshwater usage, however, hydroponic farms recycle water used in the production system; they use >90% less water than traditional agriculture. They’re able to use less water because they pair soilless growing techniques with technology and a scientific approach to growing that ensures no water is wasted. Conventional crops waste a lot of water due to evaporation and inefficient soil. Vertical farmers aren’t at the mercy of the weather the way conventional farmers are. Rain or shine, plants in vertical farms receive the nutrients and water that they need. Drought is much less of an issue, and hot days don’t require more irrigation.

Vertical farmed food also advertises the huge reduction in ‘food miles’ represents from collecting your food freshly harvest across the street. Compared to food that often travels thousands of miles by sea and over land before ending up on our plate vertical farms have drastically shorter supply chains. Vertical farms also reduce or eliminate the requirement for plant production chemicals compared to soil grown leafy crops. In the latest report about pesticide residues, the Environmental Working Group says that 70% of conventionally grown fruits and vegetables contain up to 230 different pesticides or their breakdown products. These compounds are needed to get rid of pests, but also to keep plants in peak condition during transport. Vertical farming eradicates this need.

While shipping food can result in significant saving of the climate impact of shipping food over long distances, the impact of energy-intensive food raising methods can be far greater than that - 44,000 pounds of CO2 per container per year - not counting any additional heating costs. The dependence on artificial lighting results in a greater environmental footprint and not offset by the transportation saving. An estimated 1200 kilowatt hours of electricity are required per kilogram of edible tissue for fleshy plants such as tomatoes. For vertical farms to produce America’s annual vegetable crop, the lighting requirement would use over half of the electricity the country generates every year. Given such a huge energy bill what about using renewable resources of electricity?

Headline #4: Vertical Farms can use renewable resources

Vertical farms require a lot of energy to run but availing of renewable sources won't necessarily lower the costs. The addition of large amounts of proposed solar panels to ensure the system is carbon neutral spirals into some interesting circular logic:

Can we use solar arrays and wind farms to convert sunlight's energy into electric current that would feed lamps, to convert a portion of that electrical energy into artificial sunlight to shine on plants, so they can convert that light energy into food. Head spinning? Would it be simpler to let crop plants do what they do best: capture cost-free, emissions-free sunlight for themselves, directly? One country has found a genuinely sustainable way out of this loop. Controlled Environment Agriculture utilizes the best of new technologies in horizontal farms. With a population of 17 million, and an area of just 41,000 km2 - including 7,800 km2 of open water the Netherlands is the world’s second-largest exporter of food trailing only the United States, which has 270 times its landmass. In 2017 the Netherlands exported a record $108.2bn in agricultural goods.

Heating 4000 ha. of greenhouses should come at a huge cost, but Dutch farmers are using geothermal heating to offset this by pumping warm water from deep wells to heat them, dramatically reducing the need for fossil fuels and natural gas. Greenhouse heat is then recycled to heat local schools and swimming pools - leading to the development of a circular agricultural system. Dutch farmers and innovators believe that they are creating the blueprints for the CEA food production systems of the future.

Headline #5: Vertical Farming is the future of agriculture

The above concerns should not suggest that vertical farming doesn’t have a future in agriculture, just not necessarily the one you read about in the papers, and not one that can replace open field farming. While the percentage of the global arable acreage addressable by vertical farms is less than 10%, the global vertical farming market size is still anticipated to reach USD 9.96 billion by 2025. The factors driving the growth of Vertical Farming are very potent. Government subsidies, billions of investment dollars, the continuous improvement of technology and genetic advances to name a few. VF is here to stay. The major question is which models will thrive.

The founder of Aerofarms recently said that Covid-19 has brought "greater appreciation of how fragile the supply chain is and raised questions about food safety and security." Between climate change, droughts and now pandemics, vertical farming will certainly play a part in our future, and it’s exciting to see where new technologies will take the concept. Whether or not it will be the (LED) light at the end of the tunnel remains to be seen, but regardless, there is a definite need for humans to have food production options that are independent of natural cycles and the advantage of year-round production is a major step in the right direction.

The comparison vertical farming might suffer from is the question what other changes could such huge investments effect if applied elsewhere? Drip irrigation, better grazing systems that lock up soil carbon, and novel systems to recycle on-farm nutrients. Innovation and capital are also needed to help other parts of the food system, especially in tackling food waste, and getting people to shift their diets towards more sustainable directions.

If people really want to make cities greener - in all senses of the word - rooftop farming is a perfectly noble and sustainable route to take. While it doesn’t boast of being able to provide the same scale of produce, it uses natural sunlight and helps to cool buildings, ultimately reducing carbon emissions. Brooklyn Grange farms more than two and a half acres of rooftops in Brooklyn and Queens, and then sells what it produces to New Yorkers. Hopping across the pond Manchester in the UK has calculated it has 136 hectares of unoccupied flat roofs, one third of the city’s inner urban area. That’s a lot of room for growth. Although they can’t grow as much food, rooftop greenhouses need 70% less energy per square meter than artificially lit vertical farms.

Yes, Vertical Farming has extraordinary potential to change the way we produce food, or at least some foods, and will continue to be incredibly well funded. Whether or not you believe Controlled Environment Agriculture, and specifically Vertical Farming, will solve the problem of feeding our growing population however, it’s important to distance yourself from the hype. The world’s rapidly increasing population allied to the tightening supply of usable farmland is worrying but hopping on the bandwagon of each new media trend won’t fix these problems. Innovative food solutions are plentiful, but critical fact-based evaluations are required to arrive at a balanced solution when considering the heady question of how we can feed our future.

Thanks for research and writing of this blog to Laura Kane.  Comments and critiques from Don Goodwin, David Hunt and Chad Brommer included where possible.