Vertical farms are taking the agricultural and tech industries by storm. They produce significantly more crops in a smaller space and with virtually no need for pesticides or other hazardous chemicals. And they do this using substantially less water than conventional, soil-based growing methods.
Vertical farms use less water because they pair soil-less growing techniques with technology and a scientific approach to growing that ensures no water is wasted. A significant quantity of water is wasted when growing crops conventionally due to evaporation and inefficient soil.
But this only gives a glimpse at what vertical farming can do to save water. In this article, we will discuss all the ways that vertical farming helps conserve water, why it’s important, and how vertical farming is more efficient than conventional farming methods.
Does Vertical Farming Save Water?
While improving irrigation systems and implementing more sustainable growing practices among farmers can help improve these numbers, conventional farming can never reach the water consumption efficiency offered by vertical farming.
Agriculture is responsible for 80-90% of water consumption in the United States, according to the USDA. Vertical farm companies like Fresh Box Farms says they use 99% less water than conventional farming methods. The amount of water saved depends on the set up of each farm, but even if this is an overestimate and vertical farming only saves 80% water, it is still a lot of water.
How Much Water Does Vertical Farming Save?
Getting exact numbers on how much water is saved is hard because every vertical farm is different, and every conventional farm is as well. We can look at a practical example using some hard numbers to get an idea of how much water vertical farms can save.
The USDA estimated that water use in 2015 was estimated to be approximately 322 billion gallons a day. That means approximately 257.6 billion gallons a day went to agriculture if we use the figure from above that stated agriculture used at least 80% of water consumption.
If all of these farms converted to vertical farming methods, about 206 billion gallons of water per day would be saved. Even if it only reduced water consumption by 50%, it would save 125 billion gallons of water per day (that’s 47,720 BILLION gallons a year). The number is so immense that it is barely comprehensible.
Now, these figures should be taken with a grain of salt because not all crops are cost-effectively grown in the vertical farming environment (at least not yet). Growing wheat in vertical farms, for example, is not considered viable.
Additionally, it isn’t clear what the USDA meaning by agriculture. They may include livestock agriculture in their calculations, and livestock agriculture also uses a large amount of water.
Why Do Vertical Farms Use Less Water?
So, we know that vertical farming can save massive quantities of water from being wasted every year, but how is it that vertical farms save so much water? It hardly seems possible. Let’s take a look at some of the systems and practices vertical farms implement to reduce their water consumption.
Less Water is Lost through Evaporation
Conventional farms waste a lot of water due to evaporation. In attempting to water their plants, they are also watering the air in some respect. On a hot summer day, as soon as the water makes contact with the air, it will begin to evaporate. This is not a problem in vertical farms.
Vertical farms are, in essence, closed systems. The entirety of the farm is enclosed inside of a building. Water may evaporate inside this closed system, but it doesn’t have anywhere to go and can be recycled. Vertical farms are typically designed to keep crops at an optimal level of humidity. Excess water is pulled from the air and put back into the system.
Water is Recycled
Most vertical farms also recycle the rest of the water that is not used by plants or evaporated into the air. For example, the nutrient water used to feed the plants isn’t wasted if the plant doesn’t use it. It just goes back into the system. It may be filtered or processed, depending on the vertical farm’s system.
The plant takes what it needs, and the water is recycled so that other plants can use it. How well this system works and how much water is saved will depend on the technology used within the vertical farm. The best vertical farms can operate with extreme efficiency.
Software Regulates Water Usage
Vertical farms tend to be heavy on technology. Some of them use robots to care for plants or even harvest crops. To save water, vertical farms use sensors and software to determine just the right amount of water to give each plant and when to give it.
This software helps vertical farms reduce their water consumption by preventing overwatering or watering at inefficient times. On a conventional farm, farmers have to guess more and may end up providing water when it isn’t necessary or not enough water, which could stunt growth.
Soil-less Growth Mediums are More Efficient at Delivering Water
Soil isn’t actually all that great at delivering water and nutrients to the roots of plants.
Picture this. A farmer sets a sprinkler over his crops. Some of the water evaporates quickly. Some of it seeps into the soil where ever it lands. Some of the water will seep into the soil near where plant roots are, and some of it won’t. Some of it seeps away from plants and is wasted, and some of it continues to evaporate. You can easily see all the ways this isn’t an efficient system.
Soil-less growing mediums are fantastic at drawing water to the roots of the plant, and in some systems, roots have direct access to water, but this works a little different depending on the type of hydroponic or aeroponic system used in a vertical farm.
Conventional Agriculture Methods Often Degrade Soil Quality
Some soils are better at retaining water for use by plants than others, but conventional agriculture practices often degrade the quality of the soil either by intensive farming practices or chemical treatments like pesticides.
Degraded soil is even less likely to be effective at delivering water and nutrients to plants, which leads to overwatering.
This isn’t an issue in vertical farms because there is no soil and the growing mediums used are efficient at drawing water to a plant’s roots.
Weather Conditions Do Not Impact Water Requirements in Vertical Farms
Barring catastrophic weather events that take out power or cause destruction to buildings, vertical farmers aren’t at the mercy of the weather the way conventional farmers are. Rain or shine, the plants in vertical farms receive the nutrients and water that they need.
Drought is much less of an issue, and hot days don’t mean they need to give their crops more water. Remember, the water isn’t evaporating away!
Vertical Farms Keep Waterways Clean by Polluting Less
There is a sneaky way that conventional farms “use up” water that would otherwise be perfectly fine to consume or use on crops: pollution. Chemical runoff from farms is a real problem. Many farms use chemical fertilizers, pesticides, fungicides, herbicides, and similar products to protect their plants and keep them “healthy.”
During rain (or watering by sprinkler systems), these chemical travel with the water into local waterways, causing them to be polluted and unusable.
This is not a problem for vertical farmers because of the closed environment. Plants aren’t exposed to many pests or diseases, and the problem is much easier to solve using methods other than chemicals.
Why Water Conservation is Important
The Earth is made up mostly of water, which might make you wonder why it is so important to conserve water, but only a small percentage of the Earth’s water is freshwater, and even less is drinkable. Most of the Earth’s water is saltwater, which isn’t good for crops or people to consume.
In some regions, droughts are rare, but water is scarce and protected in others. Using less water to grow our food provides several benefits:
- It helps make periods of draught less problematic for farmers and the people living in impacted areas.
- It helps keep local lakes useable for recreation and for local wildlife.
- It helps make sure there is water for everyone to use and reduces conflicts between communities over water.
- It helps make sure water is available to grow food and care for livestock.
Remember, freshwater is not an unlimited resource. It can be used up, and many places around the country and around the world live with water scarcity.
Is Vertical Farming More Efficient?
When it comes to water consumption, there are no ifs, ands, or buts about it. Vertical farming is the most efficient way to grow crops, but water conservation isn’t everything. What about the resources it requires to run a vertical farm? The energy consumption? How much can you grow inside of a building?
Let’s take a look at the overall efficiency of vertical farming.
Vertical Farms Produce More Food Per Square Meter
You’ve probably already figured out that by using vertical space, vertical farms can produce massive quantities of produce with a small footprint.
But this isn’t the only reason vertical farms are a more efficient use of space.
They also have better crop yield. For example, vertical farms can produce about 20 times more lettuce per square meter compared to conventional farming, according to EIT Food. This has to do with the plant’s nutrient, light, and water needs being met with a precision that is not possible on soil-based farms, and the fact that vertical farms can operate year-round.
Vertical farming is clearly a more efficient use of space!
Vertical Farms Have Reduced Transportation Needs
Vertical farming is more efficient when it comes to transportation as well, and transportation costs are one of the main causes of price fluctuation in produce.
Two-thirds of the United States’ fruits and nuts come out of California, which means they have to be shipped thousands of miles across the country in order to reach hungry consumers. “Local” good is often considered any food that travels less than 500 miles. That doesn’t sound very local when you think about it, though, does it?
Vertical farms bring a whole new meaning to local farming. The idea is that every major city would have at least one, and probably several, vertical farms right inside of the city or just outside of it. This greatly reduces the number of miles produce must travel, the costs associated with shipping, and the carbon footprint of shipping produce.
Vertical Farms May Not Be Energy Efficient
Most of the talk about the energy efficiency of vertical farms is fairly negative. It takes a lot of LED lights to grow all those fruits and vegetables! Let’s take lettuce as an example as there has been some research done in this area.
- It is estimated that a square meter of lettuce grown in a greenhouse requires approximately 250 kWh per year, according to this study.
- On a vertical farm, that same square meter of lettuce would require 3,500 kWh of energy per year, according to this study.
It seems pretty clear that greenhouses have the advantage when it comes to energy use, but there are some complicating factors including:
- Vertical farms have the potential to use far less energy for transporting produce.
- Vertical farms can choose to use renewable energy sources like wind turbines.
- Some vertical farms make use of skylights and large windows to reduce their reliance on LED lights.
- Vertical farms have higher yields, which reduced the amount of energy consumed per pound of food grown.
- Conventional farms use energy too. Consider the transportation needs of workers and the fuel consumed by farm equipment, irrigation systems, crop dusters, and other equipment.
- You are more likely to lose crops due to weather conditions and need to replant. The energy use per pound of food that makes it to market would then increase.
So, it isn’t as clear cut as some would have you believe. More studies need to be done to look at the amount of energy required to grow and transport a variety of different plants in different settings to get a concrete answer. It is possible that vertical farms use more energy, but how much isn’t clear.
Vertical Farming Requires Fewer, but More Skilled Workers
Believe it or not, finding laborers for farms is a huge problem among conventional farmers. Just check out this article by USA Today. It is a longstanding trend. Because a lot of what happens in a vertical farm is automated, it requires fewer workers.
The workers that it does require are usually very well educated. Vertical farms require computer scientists and engineers.
The one exception to all of this is pollination. Conventional farmers usually rely on insects for pollination. Vertical farmers typically hire people to manually pollinate the plants. However, this is something that could be automated in the future.
Vertical Farming Makes Use of Technology to Increase Efficiency
Vertical farms lean hard on their technology to run efficiently and to maximize crop yield. Sensors are used to monitor plants, and software is used to optimize plant care. Here is a basic idea of how this works:
- Data from sensors is sent to computer software. This data could include temperature, humidity levels, and even specific information about each plant.
- The software takes this data and what it already knows about a particular type of plant and calculates the care needs of each plant.
- It then tells the farm exactly how much light, water, and nutrients the plant needs for optimal growth.
- It may also make adjustments to the humidity levels or temperature in the farm to keep the “weather” optimal for plant growth.
- If the vertical farm makes use of AI technology, the more data the system is given, the smarter it becomes.
Pretty neat, right? This technology makes for a super-efficient farm because nothing is wasted, and crop yield is maximized. Plants are given exactly what they need to thrive and nothing more.
Vertical Farming is the Way of the Future
With the population growing and the effects of global warming devastating conventional farms around the world, it is becoming more and more clear that vertical farming is the way of the future. It solves many of the problems faced by conventional farmers, produces more vegetables, and wastes far less water.
The main reason vertical farms are taking off yet is that the state up costs are prohibitive. A single vertical farm can cost in the hundreds of millions of dollars to build. Until people start seeing the success vertical farms can have, they aren’t likely to invest the kind of money required to get one off the ground.
But as the need for vertical farms grows, the technology used in them advances and becomes more available, and the vertical farms out there begin showing that they can be profitable, more and more funding will become available through private investors and likely grants from the government.