Chicago Warehouse Becomes Net-Zero Urban Farm

Plant Chicago, NFP/Rachel Swenie

Here in the U.S. we have no shortage of unused industrial space. In cities across the country there are blocks of old warehouses laying dormant and forgotten. While some find second lives being renovated into hip residential lofts, many of these buildings have a hard time being fashioned with new uses. The manufacturing industry has not exactly rebounded in America and conversion into retail space can be complicated for buildings too far away from active streetscapes. For most of these icons of a former era, the easiest option is vacancy which levels double the weight on a commodity filled with latent energy that was once so useful. Not only are empty buildings a waste, but foregoing maintenance for long enough eventually degrades the components of the building to the point where it truly is unusable.

In Chicago’s West side, a group of entrepreneurs saw one such building as an opportunity and fashioned a multi-faceted program mix to utilize old warehouse space and create  a complex that will be energy-neutral, waste negative and resource positive. Dubbed “The Plant” the facility that is currently in the construction/renovation stage includes multiple parts revolving around food production that create an interconnected system of reflexive benefit (what some could call an Industrial Ecology). According to the owners, when the facility is complete it should be producing food, fish, beer and tea all as part of an on-site ecological system.

When setting out to create a net-zero urban farm, the founders of The Plant leveled their sights on an old warehouse that had already passed through the hands of multiple owners and respective uses. Built in 1925 as a meat-packing warehouse by children of a German immigrant, the Peer Foods building sits near the old Union Stockyards and holds 93,500 square feet of opportunity. Despite the fact that the building needed some work upon its discovery, the Plant team saw the structure for its accolades rather than its shortcomings.

One of the first signs of the success of the system is that, like an ecosystem, there is no real beginning or end. Given the program of the building as a farm, let’s start with the produce. The Plant proposes floors of vegetables grown on racks without soil. One thing a turn of the century warehouse is short on is daylight. Even with the new high efficiency windows that the project is installing, the plants need more light to grow so these veggies will be supplemented with grow lamps. In order to accomplish all of this, the produce will need water, nutrients, carbon dioxide and electricity.

Hydroponics? Aquaculture? Try Aquaponics!

The Plant’s second export is fish, in this case Tilapia, that are grown in tanks. Anyone who had a fish tank as a child knows that eventually the water gets dirty and needs to be cleaned. In fact, amount of fish waste that can be produced and released into natural ecosystems is one of the gripes with many current aquaculture facilities. Here they try something different by linking the water of the fish and that of the plants together.

According to the project team, Tilapia produce ammonia-based waste that is sent through a biofilter where solids settle out and the rest is broken down into nitrates. Those nitrates are then fed to plants growing in hydroponic beds. By absorbing the nitrates, the plants clean the water, which is returned to the fish. The Plant will sell both the fish and the vegetables to local food markets and restaurants, and will do so at a profit. A symbiotic relationship proves to have a synergy that makes it better than either separate system on its own.

Drinks On the House

Other components of the facility are breweries, one for beer and another for Kombucha (tea). Aside from more cash crops, the fermentation process of both of these beverages absorbs oxygen and expels CO2.  By linking the fermentation rooms to the growing rooms the increase in carbon dioxide concentration should point to improved growth in the produce. The spent barley from the brewing process? It turns out they can feed it to the fish!

By now we have a series of valuable commodities to sell, but we are still short on a power source and have a collection of waste streams:

• Plant waste from produce
• Solid waste from Tilapia
• Spent grain from the brewery
• Human waste from toilets

Both of these problems are solved at the same point with the installation of an anaerobic digestor (similar to the design proposal for the vertical farm in a NYC Waste Transfer Station). Kind of like a big stomach, the oxygen deprived chamber houses the decomposition process of organic waste–in this case, an estimated 10,000 tons per year. The lack of oxygen turns the byproduct into methane that can be captured and burned in a turbine to produce electricity (to power grow lights and water pumps) and steam. When combined with absorption chillers, the turbine operates as a coveted tri-generation system producing power, heating and cooling for the complex. The sludge from the digestor can be sold to local soil blenders as a natural fertilizer components. Contrary to a traditional, rural farm, all of these components are protected from drought, insects and floods inside a stable environment, underscoring the advantages of vertical farms.

While it is easy to get caught up on the beauty of such a balanced and interconnected system, it is important to not lose sight on how it connects back outside of the warehouse walls to Chicago at large. First and foremost, there are a series of healthy food crops that are sold in an urban center where demand for them is most concentrated (but without all of the chemicals to produce or the energy to transport). Secondly, the facility provides jobs (the team says 125) to a depressed area of Chicago not only through the construction, but the running of the facility over time.

Last, and certainly not least, is the gift of information. According to their website, the team at the Plant plans on creating a complete case study of their endeavor, including financials, to be available to the public… for free. In a way this is the most sustainable aspect of the entire system and separates it from important innovation held back by the desire to be in the 1%. The stated goal of the project is to help propagate solutions for sustainable farming and as such all of the lessons learned will be for the education of all who are interested in taking part.

*This reminded me of how William Rawn & Associates compiled their research on double skin walls and released it gratis to the public after their work on the Cambridge Public Library.

Like natural ecologies, this one has the flexibility to grow over time. According to the founding team, the future of the Plant could include bee hives or chicken coups, adding more resources linked into the larger system for which we foster a continuous demand. The collection of components that have already put together is rather complex, so much so that it makes me wonder if some simpler components could be added over time that would only add to the benefit of of the facility and its impact on the surrounding city. With plenty of vacant roof space there is prime location for capturing the sun’s energy either with photovoltaic panels or evacuated solar tubes. Even if the building finds itself more than covered on heat and power, a green roof could foster a microclimate for bees and birds while helping to capture and mitigate stormwater runoff. Rainwater collection (which could already be planned) would also be an easy addition to minimize potable water drawn from municipal pipes.

Admittedly, The Plant has been in construction for some time now, but I could not help touching on such a fantastic model that, if successful, has the opportunity to serve as a prime example for business plan development not only for urban farming, but American business as a whole. With so many saleable products, a business mix like this could serve as a solid anchor to eventually link urban farming with residential units. Can we get one in New York City?

Image Credit: flickr.com/ThePlant