Indoor farms remaking produce market, but planet pays
No one would argue that the climate in North Texas is ideal for growing lettuce, a crop that thrives when there’s a chill in the air. But the region’s broiling summers are of no concern to Eddy Badrina, chief executive of Eden Green Technology, a vertical, hydroponic greenhouse company just outside Dallas.
The company, which sells its leafy greens to Walmart, controls every aspect of a plant’s life. At its 82,500-square-foot facility, cool air is pumped in to create the ideal microclimate around each head of baby butterhead and romaine lettuce. Seven miles of pipes deliver nutrient-rich water. Although natural light floods the space — setting it apart from vertical greenhouses that block out the sun in favor of controlled lighting — additional LED lights obey a programmed algorithm directing them to shine just the right amount of light on each plant.
“We’re pretty agnostic to the outside environment,” Badrina said.
As the effects of climate change intensify, bringing more severe droughts, flooding and pest infestations, some growers are wresting control of their crops away from nature. Huge high-tech greenhouses and smaller vertical farms — windowless warehouses that typically grow plants stacked in trays — hold the promise of letting farmers grow almost anywhere.
But all that control comes with an environmental cost. Inside these facilities, farmers are creating the perfect growing conditions with power generated mostly by burning fossil fuels, and lots of it.
“It’s a lot of the same technologies you’d see in a building for human comfort, but being put to use for plants,” said Jennifer Amann, senior fellow in the buildings program at the American Council for an Energy-Efficient Economy, a nonprofit focused on reducing energy waste. “There’s extraordinary water efficiency in these facilities, but energy is really the Achilles’ heel.”
In colder climes, indoor farm operators heat their greenhouses with natural gas or propane, since these fossil fuels are often the cheapest option. Vertical farms are a smaller slice of the market, but they typically consume much more electricity than greenhouses to replace natural sunlight and to power cooling and dehumidifier systems.
Nationwide, the industry is on the rise. Between 2017 and 2022, land used to grow vegetables and herbs in greenhouses increased by more than 20 million square feet, an 18% jump, according to the federal government’s latest agriculture census, released last month. Though crops grown in indoor farms are still a small percentage of what’s on grocery shelves, they are making inroads in certain parts of the country. In New England, about 20% of the leafy greens for sale come from controlled-environment agriculture outfits.
Energy use in the industry varies widely depending on greenhouse size and what crops are being grown. A study of 12 indoor farms by the nonprofit Resource Innovation Institute found that five of them used as much energy per square foot as a hospital. One vertical farm, an outlier, was guzzling as much energy per square foot as a data center.
These companies advertise their produce as safer, more nutritious and fresher than field-grown produce, since their operations typically skip pesticides and are within a few hours’ drive of major cities. They boast of using one-tenth of the water, a claim backed up by independent research. But they don’t often talk about their energy use; most states don’t require them to report it, and researchers said many are reluctant to share this data.
With detailed energy-use information hard to come by, quantifying the carbon footprint of indoor farming is tricky. Researchers studying the industry’s greenhouse gas emissions have reached contradictory conclusions.
A comparison of studies tallying the emissions of greenhouse-grown and field tomatoes suggests that those grown indoors had a carbon footprint six times as large. But a paper summarizing research on lettuce growers’ emissions reached a different finding: Carbon pollution from indoor farms was lower than that of traditional farms because they were closer to their buyers and didn’t have to ship their salad greens hundreds or thousands of miles in diesel-burning trucks.
A few vertical-farm companies, like Texas’ Eden Green, have responded to the problem of dirty energy by focusing on efficiency. Eden Green’s hybrid model uses natural light, and the company lessens the burden on its cooling system by using programmed vents to control heat and humidity. Badrina estimated his two farms use about a quarter of the electricity consumed by a typical vertical farm growing leafy greens, which has allowed the company to plant other crops, such as herbs, that are more energy-intensive.
Badrina said he’s noticed other growers beginning to pay more attention to their energy use after a series of high-profile failures in the vertical-farming industry last year. Still, the upfront costs of energy-efficient technology sometimes outweigh the incentive of lower utility bills.
And as some companies look to build vertical farms in the swampy Southeast, Badrina said they are likely to face even higher power bills from all the energy needed to counter the region’s heat and humidity.
“People are coming up with more-creative solutions for energy sources, but I think they’ll always struggle with the energy usage,” he said.