I have a fascination with Urban Agriculture, more recently so due to the strategies that are being considered for implementation that either maximizes production per land acre, or maximizes the amount of acres used in the City for ephemeral or permanent farm operations. A recent post by WebUrbanist, '5 Urban Design Proposals for 3D City Farms: Sustainable, Ecological and Agricultural Skyscrapers' had some interesting prototypes summarized as well - which will undoubtedly show up later in L+U in greater detail, building upon a number of previous posts on rooftop/building urban ag models.
On a related note - have you ever run across a couple a stories that provide such depth and understanding of a subject that you pretty much have to share it with everyone, practically verbatim? Here's a great example, an article in New York Magazine entitled 'Skyfarming: Turning Skyscrapers Into Crop Farms' is one of those pieces that seems to be almost a primer on the subject. I myself had some questions prior to going in - the following is a step-by-step guide to some of the essential components that managed to answer all of my questions (almost!).
Either way, it's a good story and good storytelling - even if a bit much. All quotes and images via the article, authored by Lisa Chamberlain with graphics support via: Architectural Designs by Rolf Mohr, Modeling and Rendering by Machine Films; Interiors by James Nelms Digital Artist @ Storyboards Online.
The article focuses on the work of Dr. Dickson Despommier: "...a professor of environmental sciences and microbiology at Columbia University, who believes that “vertical farm” skyscrapers could help fight global warming... Imagine a cluster of 30-story towers on Governors Island or in Hudson Yards producing fruit, vegetables, and grains while also generating clean energy and purifying wastewater. Roughly 150 such buildings, Despommier estimates, could feed the entire city of New York for a year. Using current green building systems, a vertical farm could be self-sustaining and even produce a net output of clean water and energy."
(well as basic as possible...)
1. The Solar Panel Most of the vertical farm’s energy is supplied by the pellet power system (see over). This solar panel rotates to follow the sun and would drive the interior cooling system, which is used most when the sun’s heat is greatest.
2. The Wind Spire: An alternative (or a complement) to solar power, conceived by an engineering professor at Cleveland State University. Conventional windmills are too large for cities; the wind spire uses small blades to turn air upward, like a screw.
3. The Glass Panels: A clear coating of titanium oxide collects pollutants and prevents rain from beading; the rain slides down the glass, maximizing light and cleaning the pollutants. Troughs collect runoff for filtration.
4. The Control Room: The vertical-farm environment is regulated from here, allowing for year-round, 24-hour crop cultivation.
5. The Architecture: Inspired by the Capitol Records building in Hollywood. Circular design uses space most efficiently and allows maximum light into the center. Modular floors stack like poker chips for flexibility.
6. The Crops: The vertical farm could grow fruits, vegetables, grains, and even fish, poultry, and pigs. Enough, Despommier estimates, to feed 50,000 people annually.
Aside from the massing and program elements - there are ample opportunities for high tech innovation as well in the vertical farm - including power generation and on-site sewage treament. Some detail on this system:
1. The Evapotranspiration Recovery System: Nestled inside the ceiling of each floor, its pipes collect moisture, which can be bottled and sold.
2. The Pipes: Work much like a cold bottle of Coke that “sweats” on a hot day: Super-cool fluid attracts plant water vapors, which are then collected as they drip off (similar systems are in use on a small scale). Despommier estimates that one vertical farm could capture 60 million gallons of water a year.
3. Black-Water Treatment System: Wastewater taken from the city’s sewage system is treated through a series of filters, then sterilized, yielding gray water—which is not drinkable but can be used for irrigation. (Currently, the city throws 1.4 billion gallons of treated wastewater into the rivers each day.) The Solaire building in Battery Park City already uses a system like this.
4. The Crop Picker: Monitors fruits and vegetables with an electronic eye. Current technology, called a Reflectometer, uses color detection to test ripeness.
5. The Field: Maximization of space is critical, so in this rendering there are two layers of crops (and some hanging tomatoes). If small crops are planted, there might be up to ten layers per floor.
6. The Pool: Runoff from irrigation is collected here and piped to a filtration system.
7. The Feeder: Like an ink-jet printer, this dual-purpose mechanism directs programmed amounts of water and light to individual crops.
8. The Pellet Power System: Another source of power for the vertical farm, it turns nonedible plant matter (like corn husks, for example) into fuel. Could also process waste from New York’s 18,000 restaurants.
9 to 11. The Pellets: Plant waste is processed into powder (9), then condensed into clean-burning fuel pellets (10), which become steam power (11). At least 60 pellet mills in North America already produce more than 600,000 tons of fuel annually, and a 3,400-square-foot house in Idaho uses pellets to generate its own electricity.
So... the question is not whether we can do this. I have the utter faith in our ability to make anything work technologically. The bigger issue should be: Is this the best way to build, grow, and feed ourselves? I understand the utopian vision of wanting to explore these visions, but a big question - is this sustainable? While defining the concept is difficult, there are certain limitations with technological solutions to things that i fear is that the human element of food production get's lost in the search for more production on less land.
Some rationale the article: "Why build vertical farms in cities? Growing crops in a controlled environment has benefits: no animals to transfer disease through untreated waste; no massive crop failures as a result of weather-related disasters; less likelihood of genetically modified “rogue” strains entering the “natural” plant world. All food could be grown organically, without herbicides, pesticides, or fertilizers, eliminating agricultural runoff. And 80 percent of the world’s population will be living in urban areas by 2050. Cities already have the density and infrastructure needed to support vertical farms, and super-green skyscrapers could supply not just food but energy, creating a truly self-sustaining environment."While maximizing production to available acres is good - and reducing food miles by producing (in a sustainable way) food as close to the consumer as possible - we provide a good basis for fundamental sustainability. I applaud and understand this idea - but there are a few issues missing from the discussion.
One: decentralization of food supplies offers us flexibility in dealing with potential problems associated with local conditions. I don't mean growing all of our food in one spot - but concentrating production to a small set of buildings makes them susceptible to failure and blight on a grand scale.
Two: the automation of the facility loses one of the essential components of agriculture - job creation and economic stability for rural regions. Instead of concentrating farming in small scale operations with few humans, maybe we can efficiently manage production using more eyes and hands on the product... leading to better management of soils, water and other resources.
Three: Elimination of agricultural lands as both a cultural and ecological system - and missing the benefits of both of these contributions to human beings and nature. Industrial agriculture has tainted what used to be both a noble and beneficial profession that had a strong land ethic, shaped our landscape with 'amber waves of grain' and provided a place and purpose for many people worldwide.
The concentration and use of buildings and new forms of agriculture will be a necessary component to our overall food production system - but these should never be seen as the panacea for sustainable agriculture. Changing from more local production, in a variety of means, done in a sustainable manner - is the real key to a truly sustainable agriculture. In dense areas where there are certain limitations to growth of adequate food supplies, supplementing production with vertical farming makes sense. In others, it just becomes a knee jerk and grandiose reaction to a system that is fatally flawed and inherently unsustainable (agribusiness). If we really look around and are smart about it, we can supply all of the needs of our residents with available lands, rooftops, and occasionally building - but it will really take a paradigm shift in how we both produce, transport, consume - and more vitally, think about our daily meals.