The Plant's executive director, John Edel, inside the 104-foot-long digester tube.

The Plant's executive director, John Edel, inside the 104-foot-long digester tube.

Credit: Plant Chicago, NFP/Rachel Swenie

Urban agriculture is spreading like a vine through derelict industrial centers where former production and storage facilities serve as blank canvases for organized experiments in local self-sufficiency. Among them is The Plant, a 93,500-square-foot vertical farm in a former meat-processing facility on Chicago’s southwest side that is shooting for net-zero energy. Since 2011, when we last spoke with its executive director, John Edel, the nonprofit has grown to host 13 independent businesses and has received approximately $2 million in local and state grants. In December, the team raised $65,230 on Kickstarter to fund the construction of a living wall for the building’s lobby.

ARCHITECT caught up with Edel, who is leading The Plant’s estimated $6.5 million development following his work to transform another Chicago industrial structure into a local fabrication center, about its newest tenants and the final steps in its plans for achieving net-zero energy.

Since we last spoke, The Plant has grown as a business incubator. Can you talk about the new tenants?
Among our businesses are six farms, a distributor and producer of artisan cheeses, a bakery, and a kombucha brewer. We are about to add a beer brewery. Without the brewery, we’re about 40-percent occupied; that leaves approximately 15,000 square feet of space. We’re holding off on programming the entire building so that we have some room for flexibility as research projects arise and as we modify the building’s systems.

Food waste from the bakery will soon be fed into the digester. The bakery's food products are sold locally.

Food waste from the bakery will soon be fed into the digester. The bakery's food products are sold locally.

Credit: Plant Chicago, NFP/Rachel Swenie

The Plant's hydroponic farms use water derived from the facility's aquaculture farms, which is rich in nitrates excreted by the fish.

The Plant's hydroponic farms use water derived from the facility's aquaculture farms, which is rich in nitrates excreted by the fish.

Credit: Plant Chicago, NFP/Rachel Swenie

How evolved are the building’s systems and loops?
They’re not terribly well-evolved. Pieces are in place. For example, some of the loops related to the system that consumes waste heat and humidity from one of the farms and uses it to condition mushroom-growing spaces [are functional]. All of the building’s material waste is being consumed on site. We’re doing a little bit of carbon-dioxide looping, but not on the scale we need to be. We’re actively engineering how we’ll capture the carbon dioxide from the new brewery and feed it to grow rooms. [Achieving net-zero energy] hinges on the anaerobic digester, which is expected to be completed by early next year. If the digester never happens, it would be really unfortunate but it wouldn’t be the end of the world. The Plant would continue doing what it’s doing.

Describe the anaerobic digester.
The plug-flow digester consists of two above-ground, 30-cubic-meter stainless steel feedstock hoppers—measuring 104 feet long, combined, and 14 feet in diameter—with hydraulic doors set into the ground. Trucks [from local business will eventually be able to] deliver 30 tons of food waste and other biomass each day. That material moves through the plug-flow portion and then into a press, where we will separate the liquid from the solid digestate. The solids will be sold for use in structured soils in applications such as clean-roof growing media. The liquid will go into a post digester, or a secondary digester, with a gas dome that regulates the pressure before being sold as an input to fertilizer manufacturing. Much of the income from the project will come from the tipping fees and the sale of liquid and solid digestate. They’ll actually be more than the tenants’ rents combined.

Cranes move the digester tubes into place.

Cranes move the digester tubes into place.

Credit: Plant Chicago, NFP/Rachel Swenie

In what ways are you using the building’s original structure?
We replaced all the windows but were able to reuse the envelope. The building was built in 1925, so the walls are very thick. The former owner also added a substantial amount of foam insulation—7 inches on the roof and 4 inches to 6 inches on the interior walls. The building was in continuous production for approximately 80 years, so while the owner was often replacing mechanical systems, some pieces are new and some pieces are very old and need to be torn out. The former owner moved out in 2007.

What does a day at The Plant entail?
It’s a 24/7 operation. There are people around all the time. The bakeries start at 2 a.m. and the plants are growing in the middle of the night [using artificial light]. If you’re not using natural light, you’re not bound to a normal day-night schedule. And since electricity is less expensive at night, it makes much more sense to do the bulk of the growing when it’s cheap. We sell electricity to the grid, so consuming as much power as we can at night and as little as we can during the day allows us to sell electricity at the highest possible rate and then purchase it at night when it’s at its lowest. We use the building as a storage battery.

What are your goals for The Plant?
Our overall goal is to make information available to others. You don’t have to go all the way to net-zero. You can combine outputs from one process—such as heat from manufacturing—with another process—such as an office space. The Plant is focusing on research and becoming an information hub as opposed to production farming, which is what we started out doing. Our tenants, in at least three cases, have proven the production-farming model for us by being profitable and paying their full cost in terms of electricity, space, and labor. We’re working on research partnerships with local organizations such as the Delta Institute, the Illinois Institute of Technology, and the Center for Neighborhood Technology.

What have been your biggest challenges so far?
By design, our model does not cost an enormous amount of money and it’s not looking for large loans or venture capital. The goal is to prove that a replicable model can be built for a small amount of money by using a much higher percentage [compared to peer projects] of waste stream materials and a great deal of creativity. It’s a slow-money route.

This interview has been edited and condensed for clarity.