Vertical Farming

Genius Green Giant

How can the world’s growing population continue to be nourished with fresh food in the future? One approach is known as vertical farming. Growing vegetables in windowless buildings could ensure a more ecological, safe and local agriculture in megacities and remote areas in years to come. 

Text Tino Scholz  Photos Nikita Teryoshin

The future of food has a pink glow. It fits into a hermetically sealed, windowless, 200 square-meter warehouse—about three-quarters the size of a tennis court—and contains four huge sets of shelves, each with seven levels. These shelves, lighted by 9,000 LED lamps, hold 6,000 heads of lettuce and several hundred tomato-plant seedlings. The lettuce and tomatoes are rooted in a nutrient solution instead of soil. The temperature is kept at a constant 22 degrees Celsius, the humidity at 80 percent. No insects are flying around because the system is sealed off from the outside world. “This here,” says Jasper den Besten, bathed in the pink of the LED lamps, “may someday be found all over the world, helping to feed the population.”

The future is located in Venlo, Netherlands, just a few kilometers from the German border. The area here on the Lower Rhine is famous for cultivating lettuce and other vegetables; enormous greenhouse facilities dominate the landscape. This is where the HAS University of Applied Sciences is working with several companies on a pilot project named BrightBox, led by den Besten. The goal: conducting comprehensive research to find the right mix of lighting and climate for vertical farming as well as establishing strategic partnerships with companies interested in developing vertical farming for a broader market. Den Besten, senior lecturer in alternative farming at HAS University, can talk about the topic for hours on end—from large-scale solutions down to the importance of an individual head of lettuce in his testing facility. “Nourishing the world’s population is a topic that motivates me,” he explains. “It’s about finding solutions to address the looming problems of the future.”  

High Art

High Art

The BrightBox shelves go up to 5 levels high.

It is currently estimated that nine to ten billion people will be living on Earth by the year 2050, at least two-thirds in cities. Extrapolating from today’s harvest yields, feeding everyone would require enough additional farmland to cover an area 20 percent larger than Brazil. The problem: soil is a scarce resource. Arable land is getting even scarcer—fertile soil is being lost to climate change, inappropriate farming methods, overgrazing and sealing (covering up soil with concrete or stone). To help alleviate this problem, why not move up instead of spreading out? It’s a strategy that has been used for centuries in building homes in city centers, and transferring it to farming would allow vegetables to be grown in any location around the world while saving space, staying local and removing dependency on the climate. “Inside the farm we can imitate the conditions of June 21 every day of the year and harvest every three weeks,” den Besten says, “all while retaining the same high quality.” 

Along with the savings on space, the system’s ecological benefits are its key aspect. Soil depletion and/or erosion can be reduced, and enormous amounts of water can be saved compared to traditional farming—companies already working with vertical farming report savings of up to 95 percent. The extensive use of pesticides and herbicides is no longer necessary, thanks to the integrated monitoring systems and indoor environment, which is kept free from most pests and fungi. The dependency on fossil fuels is also lower since a vertical farm doesn’t need tractors. 

When den Besten strides through the pink-lighted rows of his farm and describes how it works, he repeatedly comes back to the topic of LED lamps. “It’s thanks to this technology that vertical farming is even possible at all,” he explains. The energy-efficient light-emitting diodes have hardly any heat loss and can replace sunlight, which is naturally essential for plant growth. 


Jasper den Besten

A little more than a decade ago, when American and Japanese companies tentatively started pursuing vertical farming on an industrial scale, the LEDs in use weren’t efficient enough—the costs for lighting and cooling were too high to be economically viable. Nowadays LEDs are around ten times more effective. Improving such lighting is also something TÜV SÜD works on in its Horticulture Laboratory in Singapore (see the info box on page 26).

The closed-loop, climate-independent system makes it possible to use vertical farms all over the world. And since these farms don’t take up much land area, they can be built near cities or even centrally located within them. Vertical farms can already be found in numerous places around the globe: in Berlin, Shanghai and Chicago, and in Japan, Korea, Switzerland and Great Britain. Worldwide there are more than two hundred indoor greenhouses in operation, the lion’s share in Japan. Since the Fukushima nuclear disaster in 2011, the Japanese have a particular appreciation for the expensive-but-uncontaminated lettuce from these plant factories.

Particularly for city-states such as Singapore, which has no appreciable farmland to speak of, this technology could make a major contribution to supplying residents with food in the future, decreasing the dependency on imports. The technology corporation Panasonic runs a vertical farm in a former warehouse in Singapore that produces about 80 tons of vegetables annually. While right now this amounts to just 0.015 percent of the demand in the city-state, there are plans in the works to expand this share to a total of 5 percent.

At least that’s the theory. Whether these bold plans will ever become reality is completely up in the air at the moment, something den Besten is also well aware of. He brings us from the glowing pink main hall into a smaller box measuring 50 square meters—a bit larger than 3 parking spaces—where he can dim the lights using an app. It’s all controlled by a computer system located on the roof of the facility. A few touches to the screen of his smartphone bring this smaller unit online; the red and blue lights slowly begin to glow. “We’re going to try growing strawberries here soon,” he says. “We haven’t tried it yet because we’ll need bees.” 

Generally speaking, the concept of vertical farming is limitless—tomatoes, strawberries, potatoes and even bananas could all theoretically be grown. Practically, however, it doesn’t make sense to plant potatoes or rice, as den Besten explains: “The amount of electricity needed for lighting and climate controls would be considerably higher than for leafy green vegetables. As things currently stand, it wouldn’t be profitable.” And even in those places where things are running well, one shouldn’t get too enthusiastic: “Despite efficient LEDs, lettuce and vegetables from indoor farms usually cost twice as much as those grown out in fields; however, they do have advantages, such as being cleaner and safer—free of soil and less likely to become contaminated with illness-causing micro-organisms.”

Because of this, vertical farming for now functions as more of a complement to traditional farming, so that highly perishable vegetables such as fresh lettuce or herbs can be brought to local markets over short distances. Staple foods such as rice, potatoes and grains, which can all easily be stored over longer periods of time, will continue to be cultivated outdoors.

The company Aerofarms, with global headquarters in Newark, New Jersey in the U.S., is already further along. The company has been active in the field of vertical farming since 2004 and has become the world market leader. Its 9th farm in the U.S. is its largest, covering over 70,000 square feet —with a harvest of around one thousand tons of leafy greens annually. More farms are in the works for around the world. “We’re already competitive with farmers for pricing,” says Aerofarms co-founder and Chief Marketing Officer Marc Oshima. “This is incredibly complex thinking about the biology and the environment and the classic nature vs. nurture” comments Oshima.

Rapid harvesting.

Rapid harvesting.

The vegetables grow fast because vertical farming allows them to be harvested at much higher frequencies.

Aerofarms has taken a unique approach, bringing all of the expertise in-house. been easy.” The team of “farmers”—crop biologists, microbiologists, bio engineers, mechanical engineers, industrial engineers, lighting engineers, information scientists—has more in common with high tech than with a farmer’s long years of experience out in the fields.

Aerofarms collects millions of data points about the green lettuce leaves during their growth—using them over the years to perfect their cultivation. Everything from the light, the spraying of water and the delivery of minerals is monitored, controlled and specified. Getting Oshima on the phone isn’t easy. He’s constantly traveling around the world; there are a lot of companies interested in the systems of these North American pioneers. “I often only see our farms through the camera feeds we’ve set up,” Oshima says with a chuckle. Racks and racks of growing in towers, rising up 12 levels.

The statistics about vertical farming seem to just gush out of Oshima, perhaps because he’s pitched them to investors so many times: “The growth cycle for baby leafy greens from seeds to harvest takes just twelve to sixteen days as compared to the thirty to forty needed on outdoor fields. In a year, that’s up to thirty production cycles as compared to just two from the field. Cultivating vegetables is successful without soil. The roots of the seedlings are regularly sprayed with water during the growth period. The nutrients are delivered precisely through a water mist.”

Data analysis as practiced by AeroFarms is also an important topic for den Besten. One of the focuses of his research at the moment is the “light recipe” for optimal cultivation. “Red light ensures fast and tall growth,” he says. “A high amount of blue light makes the lettuce grow a little bit smaller, but it does increase the proportion of vitamins and other beneficial nutrients. The flavor also changes depending on the light intensity and composition. More blue light, for instance, makes basil noticeably more pungent.”

Den Besten has been working on the project since 2015. Where will it all lead? “Any prediction would be fortune-telling,” he insists. “We’re still at the start. Vertical farming has been used industrially for just over ten years now. That’s practically nothing.” Then he shuts the BrightBox doors and closes the shutters. The lights stay on, of course.

Heading back to the parking lot, Jasper den Besten sees a head of lettuce outside the BrightBox that he took out of the nutrient solution earlier. It’s too late to put it back inside. He could throw it away, but that’s really out of the question. “Good food shouldn’t end up in the trash,” he says, placing the lettuce on top of his laptop bag. “I guess I’ll be having salad tonight.”


TÜV SÜD has been testing artificial light sources used to promote plant growth in its new Horticulture Laboratory in the greater Shenzhen area in China since December 2017. “We test how light systems and the light spectrum they emit affects plant growth in our laboratory,” says TÜV SÜD specialist Marvin Böll. “The goal is a classification system that makes it easier for consumers to select the suitable product for their particular needs.”

The work in the laboratory also checks whether the artificial lights fulfill all the statutory requirements for the respective international markets. “This is interesting for customers who, for example, want to convert from conventional lamps to LED systems,” Böll explains. The fact that he and his colleagues are working on the future of food makes his work even more important to him. “Due to a variety of factors, including climate change and the scarcity of arable land, it will be necessary to find alternatives to traditional food cultivation. We want to help with finding relevant solutions.”