Vertical farming pros and cons

There are significant differences between traditional farming and vertical farming in resource use, cost, output and, in the possible locations for each.

Greenhouses are the more traditional technology that you’re probably familiar with: a single layer of crops, planted inside an enclosed space with walls and a ceiling made of glass or plastic to allow natural light in. They’re semi-controlled environments.

Vertical farms, on the other hand, are a much more recent invention using trays of usually hydroponic plants, stacked in floor-to-ceiling towers, with LED lights illuminating each layer, and climate control constantly adjusting the temperature, humidity and more. They’re fully controlled environments, based on controlled environment agriculture (CEA).

Since vertical farms are compact, closed systems, they can be built in areas that have the biggest consumer markets: dense urban areas. Since vertical farms use much less fresh water than greenhouses, places with limited access to fresh water are also ideal for vertical farms.

Doubly so if they have access to low-cost, renewable energy. And even better if they’re near a market with high demand for the crops vertical farms excel at producing: Leafy greens, microgreens, herbs and berries grown locally, without pesticides. Additionally, vertical farms can grow greens year round in very hot or cold climates.

At first blush, vertical farms are more expensive to build than greenhouses — sometimes up to 10 times as costly. Vertical farming costs $ 2,200 to $ 2,600 per square meter of cultivation bed space, while high-tech greenhouses cost $ 250 to $ 350 per square meter of cultivation space. Therefore, depending on the specific economics of your location and market, the ROI on vertical farms may be a longer-term proposition.

However, there are areas in which vertical farms actually save money vis-a-vis traditional farms and greenhouses. One of these is labor cost, which can be very high in some areas, and which automated vertical farm technologies reduce significantly. Because of proximity to the end-user, vertical farms also significantly reduce logistics costs. A higher-quality product made in a more controlled environment can also fetch higher prices on the market. Payback periods on vertical farms can vary widely, so use iFarm’s handy calculator to get a custom estimate for your location!

Let’s look at the basic factors that determine the ecological footprint of a vertical farm. These include water use, soil, pesticides and GMOs.

When compared with greenhouses — and certainly when compared with traditional farming — vertical farms use significantly less water (about 95% less than traditional farms). The water savings come from the highly controlled systems that define vertical farming: Instead of growing plants in soil, vertical farms can use hydroponics, where plant roots are submerged in water and nutrient solutions (fertilizers), or aeroponics, where water and nutrients are sprayed directly at the roots. What isn’t absorbed by each plant falls down to the next tray in the stack, and so on. Any water that reaches the bottom is recycled in the system.

Pesticides are often used in traditional farming, but are unheard of in vertical farms. Since it’s a controlled environment, there is no need to combat pests using chemicals. This makes produce grown in vertical farms "organic" (although hydroponics don’t qualify for certain Organic labeling in various countries).

In the same way that the controlled environment of vertical farms removes the need for pesticides, it essentially removes the need for genetically modified (GMO) seeds, too. Like pesticides, genetic modifications are used to help plants thrive in otherwise natural conditions, despite the nuisance of storms, draughts, pests and more. What you’re doing with vertical farms is creating the dream world for the plant, without genetically modifying it.

While vertical farms do require a significant input of electricity, the ultimate energy costs of traditional farming might be just as great, if not greater. So how do vertical farms compare to greenhouses in terms of energy use?

One of the leading critiques of vertical farming is that replacing natural sunlight with LED bulbs and climate control requires electricity — lots of it. If the source of the energy is not renewable then vertical farms have a bigger carbon footprint than greenhouses. But the opposite is also true — where renewables are available, vertical farming can greatly reduce the carbon footprint of foods that are normally trucked long distances, or flown in from overseas. For example, Norway is perfect for vertical farming, because they just have so much cheap, renewable energy and import a lot of food.

Then there’s the issue of fertilizer, which also factors into the energy equation. When you tally the emissions reductions from shorter transport distances, the reduction in fertilizer use (fertilizer production is highly carbon-intensive, and Controlled Environment Agriculture uses it much more efficiently than outdoor farms). Plus the reduction in food waste, it’s clear that there are many factors to consider when measuring carbon footprint.

Ultimately, vertical farms have many advantages, some of which require the proper location to give their full effect. They offer high-density, ultra-local production with a high level of quality control. They make efficient use of labor, and reduce both labor and logistics costs. They reduce water usage significantly, and eliminate the need for pesticides and GMOs. On the other hand, they have higher startup costs, and may bump into a high electric bill. When judging the overall energy input and carbon footprint of a vertical farm, however, you have to compare it to the big picture of traditional farming, which is energy-intensive in terms of fertilizer use and transport to markets.

30.11.2022