This Underground Urban Farm Also Heats The Building Above It

Truly local food is when it’s grown in your basement. Plantagon CityFarm wants to create a network of underground urban farms–and whole skyscrapers filled with plants.

Underneath a 26-floor office tower in Stockholm, an underground space once used as an archive for a newspaper will soon become a farm. And because of a unique business model, the urban farmers growing greens in the new farm won’t pay rent–their farm will pay for itself in heat.


Like some other indoor farms, the Plantagon CityFarm, set to begin production in early 2018, will grow greens in vertical towers under LED lights. But by capturing the heat from the lights–heat that would normally have to be vented out of the room and require air conditioning to keep the plants from overheating–the farm operators can send it into a heat storage system for the office building, and the heat can be used to help keep the offices warm through the winter.

[Photo: Refarmers]
The system will save the office building 700,000 kilowatt-hours of energy a year, worth roughly three times as much as the previous tenant of the basement was paying in rent.

“[The building owner] agreed to give us a free lease for three years, so we don’t pay one single Swedish kroner for the room,” says Plantagon cofounder Hans Hassle. “This is the challenge, very often, for urban farmers: If you really want to grow things in the city, you have to find new business models that actually make the food not too expensive in the end.”

The company plans to sell food directly to people working in the offices above, along with two restaurants that are located in the high-rise. Roughly a third of the produce will be sold to nearby grocery stores, all close enough that the greens can be delivered without fossil fuels. Another third of the produce will be sold in an on-site store in the skyscraper.

[Image: Plantagon, Sweco (Illustration)]
“In Sweden, we have a higher demand for locally grown food than we do for organic food,” Hassle says. “People tend to want to know where the production comes from.”

If organic kale or lettuce travels hundreds or thousands of miles to a store, Hassle says, the environmental footprint could be higher than the same greens, grown without pesticides or herbicides, inside the closed-loop system of the indoor farm. Like other indoor farming, the Plantagon system also uses a tiny fraction of the water used on outdoor farms. The heat is captured in water that travels in tubes over the LED lights, and then sent into a heat pump system. Carbon dioxide from the offices will also be sent to the farm, and fresh oxygen from the plants will be sent back to office workers.


The company plans to open 10 underground farms in Stockholm over the next three years, working in buildings that already have underground heat pump systems. The team is also talking to a local power company about whether its heat could be sold into the larger district heating system that connects to other buildings throughout the city.

A two-hour drive away, in the city of Linköping, the company is planning an indoor system on a much larger scale: a 16-story “plantscraper” that will produce food throughout the building. Two-thirds of the building will include office space that can be rented to make the system financially viable, and, as in the underground farm, heat from the greenhouse will help heat the rest of the building. Conference rooms at the end of each floor will have views of the farm. The company and partners are still finalizing leases with prospective tenants, but plan for the building to be open in 2020 or 2021.

[Image: Plantagon, Sweco (Illustration)]
A similar farm is planned for a building in Singapore, where the lack of land for farming means that most produce is imported from other countries such as Malaysia. As Malaysia and other countries run out of its own arable land and their populations continue to grow–a pattern happening around the world–Singapore is increasingly interested in Plantagon’s vision of high-rise buildings focused on growing food locally. Cities in China that are already struggling to source enough food are also in talks with the company.

While the large-scale farms take more time to construct, the underground farms can be constructed quickly. The company is currently crowdfunding investment in the first farm. Hassle hopes to involve as many people as possible–not for financial reasons, but because he argues that citizens need to be active stakeholders in the burgeoning field of urban farming.

“To us, food production is not like running any business–food is like water, it’s a human right,” he says. “So it’s not only business as usual. This has lots to do with social responsibility and of course with environmental responsibility. That’s why we’re inviting people to be part of owning these facilities because they should have input.”

The company is also structured to be controlled partly by a nonprofit founded at the same time, a business model chosen to keep the company committed to larger goals than just maximizing profit. It’s a somewhat similar approach to B Corporations in the United States.


“We tried to not only speak about this–because that could be lots of corporate bullshit when you say things like this,” Hassle says. “We actually try to institutionalize this in what we’re doing through the articles of incorporation and letting people be part and actually have influence over what we do.”

About the author

Adele Peters is a staff writer at Fast Company who focuses on solutions to some of the world's largest problems, from climate change to homelessness. Previously, she worked with GOOD, BioLite, and the Sustainable Products and Solutions program at UC Berkeley.