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Cities+Nature

These fine-tuned veggies grow beneath an artificial dawn

Thanks to LED technology, indoor farming is making a comeback.

By Tony Rehagen

It’s 1 p.m. on a Monday in the Cincinnati suburb of Hamilton, Ohio. But inside a windowless 70,000-square-foot structure in an industrial park on the outskirts of town, the “sun” is only just rising.

In a sealed room within the factory, dozens of LED grow lights awaken, dispelling the darkness of a simulated night. The light-emitting diodes fill the space with a glowing pink dawn that illuminates rows upon rows of leafy greens, packed together on trays and stacked on racks up to the 55-foot-high ceiling. This is the grow zone at 80 Acres Farms, one of the country’s largest vertical farms. On any given day there, 13,000 plants per row, or 800,000 plants in all — from lettuce and kale to basil to microgreens — are somewhere on their 30-day journey from seed to harvest.

Farm manager Joshua Jones stands just outside the grow zone. Every few minutes, a hatch slides open, briefly spilling the pink LED daylight into the white fluorescent factory floor, as a conveyor belt spits out another tray of densely packed, mature lettuce. The tray is then lifted into another machine that reaps the leaves and pours them out onto another conveyor belt. There, a lone worker, gowned and hair-netted, sifts through the linear salad to pull out the few undesirables with a gloved hand.

80 Acres Farms, which launched in 2015, is one of more than 2,000 vertical farms sprouting up across the U.S., part of a $3 billion global industry that is projected to skyrocket to $24 billion by 2029. Along with other vertical farm companies like AeroFarms in Newark, Gotham Greens in Brooklyn, Bowery in New Jersey, and Plenty Unlimited in San Francisco, 80 Acres is pairing LED technology with data and advanced robotics to upend the idea of the traditional open-field farm.

In this controlled, enclosed environment, the process from seed to packaging is automated. There’s no need for pesticides or herbicides. And farming can happen virtually anywhere, from the desert to the frozen tundra to the middle of a swelling urban landscape. The technology is so unbound to the climate that astronauts are using it to grow lettuce, cabbage, mustard, and kale aboard the International Space Station — and some are even eyeing it as a way to jump-start colonies if humans ever leave the Earth.

It’s going to be a while before vertical farming takes over this planet, much less any others. Even these cutting-edge agriculturists haven’t devised a way to vertically grow the commodity crops that feed the world — like corn, wheat, and rice — in a way that makes economic sense. But right now, vertical farming is showing its potential to supplement existing food supplies, develop agriculture in otherwise ill-suited environments, and curb the carbon footprint of transporting produce over long distances. If this is the future of agriculture on Earth, these space-age diodes will light the way.


Whether it’s the future or not, vertical farming is in many ways a throwback to the past.

“It harks back to an older, early 20th-century model of every city having its own greenhouse district,” says Christopher Bosso, a professor of public policy and political science who specializes in food and environmental policy at Northeastern University. “They’d produce hot-house vegetables, even in winter. But it was a heavily energy-intensive task.”

In fact, the practice ate up so much energy that by the 1970s, indoor farming fell by the wayside. Refrigerated rail and trucks made it much cheaper to bring in produce from California and Florida, and eventually climate-controlled ships and planes opened easy routes from overseas.

Greenhouse growing, both in the city and outside, didn’t completely disappear. But the practice was far too costly for mass production. The primary expense, at least in terms of energy, was the high-pressure sodium lamps that were used when the sun wasn’t shining through the windows. Not only did the sodium lights eat up electricity, they also burned far too hot for delicate crops like leafy greens and microgreens (edible vegetable and herb seedlings).

“As long as we want what we want, when we want it, there will be a place for vertical farming.”

Christopher Bosso, a professor who researches food and environmental policy at Northeastern University

Enter LEDs, which were invented in the 1960s but only started to become efficient and affordable around the turn of the 21st century. These new LEDs not only burned cooler and cheaper but could now harness and accentuate the many different wavelengths in the visible spectrum. Red light waves promote development and yield, blue enhances leaf color, green regulates plant architecture, and a barely visible far red boosts leaf size and flowering. With each passing year, the cost of LED lights plummets while their versatility increases. Farmers can now experiment with light-related recipes that use different combinations of every part of the spectrum. They can adjust the intensity, duration, and mix of exposure to each wavelength to affect the size, appearance, texture, and yield of their crops.

For instance, when growing lettuce, they can build a recipe of red, far red, and blue lights to produce a higher yield of plants with large, dark red leaves. Cameras and sensors monitor every second of every tray of seeds in the grow zone and feed that data back to scientists, so vertical farmers can tweak light recipes to get the specific product consumers want.

Of course, light is only one component of growing a plant — there are also matters of temperature and weather. At 80 Acres, for example, the grow zone can contain up to 20 distinct microclimates at a time, allowing for diverse harvests of everything from greens to herbs to cucumbers to strawberries.

This unprecedented amount of control presents several advantages. An obvious one is increased productivity: 80 Acres’ 70,000-square-foot facility alone generates 10 million servings of produce (mostly leafy greens) per year. Since the company can recycle water and nutrients, it says it uses up to 95% less water per pound of produce than a traditional farm. Plenty Unlimited claims that its yields are up to 350 times that of open field growing; AeroFarms boasts up to 390 times the productivity.

Because of increased technology, these vertical farms tend to hire fewer manual laborers, and more skilled workers like technologists, biologists, engineers, researchers, and equipment maintenance staff. Vertical farmers say they could offset the loss of some traditional farming jobs by retraining workers in processing, packaging, and tending to the plants. “Our growers can focus on growing instead of the menial labor,” Jones says.

Vertical farms can also exist virtually anywhere that there’s enough space and power to run them. So theoretically, the produce is hours away from market instead of days and weeks. This means the greens are fresh. It’s also a significant benefit, at a time when the United Nations Food and Agriculture Organization finds that food supply-chain processes are on a pace to overtake farming and land use as the biggest contributor of greenhouse gases in the agri-food system. Vertical farming might be able to limit the environmental impact of shipping food over long distances.

One of vertical farming’s biggest advantages over open-field competitors is quality control. Since the climate is controlled and the process is largely automated, only a few humans ever handle the produce. That reduces the chances of contamination by salmonella or listeria, which have led to widespread recalls of greens.

“Over the last decade, there’s an increased concern about food safety,” says Bosso. “The downside of long food chains is that, especially for produce, you don’t know how many hands have touched it and in what conditions. In these vertical farms, fewer hands have touched it, and it’s grown in conditions that are safer. That’s not a trivial point.”


Despite the breakthroughs of LED-driven vertical farming, significant challenges remain. Even with more affordable and efficient lighting, it still takes an incredible amount of energy to run an industrial-sized operation. Vertical farms can partially offset this — for instance, 80 Acres’ production farms are run by renewable hydroelectric energy from the Ohio River. But the practice is still relatively expensive compared to what it costs to farm in the open field. “That’s why there’s no rice, corn, [or] wheat,” says Zachary Burns, manager of 80 Acres’ vine farms operation, which grows cherry tomatoes under the LEDs in a downtown Hamilton high-rise. “There’s just no profitability per square foot.”

Even in lettuce, this added expense trickles down to the price of each vertically farmed product. According to one agriculture consultant, it costs a vertical farm $3.07 per pound to grow and deliver greens, as opposed to just 65 cents per pound for conventional outdoor farms. Bosso says that vertically grown salads might make more sense in areas of the world like the Middle East, where there is no outdoor growing alternative. But in the U.S., where land is plentiful and field-grown produce still cheap, only people with means can fork over extra dollars for vertically grown salads.

“I don’t think it’ll ever supplant traditional agriculture — at least not in this country,” says Bosso. “As long as we want what we want, when we want it, season be damned, there will be a place for vertical farming, but it’ll never compete on scale and price per pound. At least not now.”

For their part, 80 Acres’ farmers aren’t trying to replace traditional farming, a trillion-dollar industry with deep social and cultural roots. They know they can’t feed the world on lettuce. But that isn’t stopping them from pushing the technology and trying to scale. They are preparing to open two new 200,000-square-foot next-generation farms, one in Georgia and one across the Ohio River in Kentucky. Each will generate three times as much food as the location in Hamilton. And they’ve just started growing strawberries for commercial release. “As we build out,” says Jones, “every farm is a testing ground for the next one.”

And since NASA is experimenting with vertical farming, the “next one” might someday be off-the-ground, in orbit or on another planet, sustaining astronauts on long-haul interplanetary expeditions.

Here on Earth, at 80 Acres’ main facility, it’s 7 a.m. on Tuesday morning. The farmers begin to arrive, filing inside from the burgeoning daylight. Inside the grow zone, though, the synthetic day is just ending. The purplish-pink LEDs dim, and the stacks of greens are once again enveloped in the black of simulated night. On one end of the grow zone, machines begin transplanting new seedlings up the conveyor belt and into the dark. At the other end, the large trays of mature plants are pushed out of the darkness. They slide out on rollers for the mechanical harvest, then to packaging and shipping, where their leaves will see natural light for the first time.

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Tony Rehagen is a writer based in St. Louis. His work has appeared in Popular Mechanics, Bloomberg Businessweek, The Washington Post, The Boston Globe, and Pacific Standard.

 

Illustration by Adrián Astorgano

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