The basic idea is simple: Create large industrial size greenhouses that can be stacked on top of each other to grow staple crops in areas with limited arable land. By enclosing the crops in a greenhouse modules, farmers in these areas gain the following benefits:
- Reduce or eliminate the weather as a factor in successful farming.
- Reduce labor costs because of high quality soil/compost.
- More efficient use of chemicals and agricultural fertilizers (nothing blows away or runs off).
- Reduce or eliminate environmental damage from agricultural runoff.
- By growing the farms up instead of out, more land can be devoted to farming without losing limited land resources.
- Increase the productivity of fields through:
- Increased use through the year (multiple growing seasons).
- Reduced chance of disease infection reduces herbicide costs.
- Reduced chance of pest infestation reduces pesticide costs.
I thought of this idea when my Mom asked my sister-in-law how her family was doing. Misty's parents are farmers in Kansas, and farming isn't easy. "All it takes" my mother said, "is one bad season and you're wiped out."
That thought came back to me as I was watching an episode of the History Channel's Modern Marvels program that talked about corn. The one thing that really stuck with me was the fact that most corn in North America takes 100 days to grow. My thought was simple: If Misty's parents could grow multiple crops every year, then they'd be less likely to have problems. But how can this happen if there are only 120 days of good growing weather?
Which led me to the next question: How to reduce or eliminate the weather as a factor?
Commercial flower growers use greenhouses to great effect, and they have a lot fewer problems with the weather. But existing greenhouses are too lightweight to allow multiple levels of farming crops.
Skyscrapers like the Empire State Building, however, could be strong enough to support multiple levels of crops. The ESB has 85 floors, and covers two acres.
But not everyone can afford a skyscraper. The ESB cost over $40,000,000 to build in the 1930's; This is well beyond the means of any small or medium farmer, even with the advances made in materials science and construction techniques.
So the system should be constructed in a modular fashion, with a basic "building block" design. Each block is able to provide one acre (4046.85 square yards [210 feet wide by 210 feet deep]) of arable land, and multiple blocks can sit atop each other like LEGO bricks. This allows the owner of the site to start a construction project and add to it as time and money allow.
In addition, the controlled environment of the greenhouse will allow multiple harvests to occur over the course of a year, so that one acre of land is actually as productive as three acres of land (if planting corn). The reduced cost of pesticides, herbicides, fertilizers, and water will also directly contribute to the economic viability of the system.
The following image shows the basic building block of the system, with dimensions and explanations of space use.
Interior growth bed is 210 feet wide, 210 feet long, and
3 feet deep (three feet of soil). There is a 20 10 foot wide border around the growing bed to allow machinery and people to move around the perimeter of the bed without disturbing the plants. The module should allow 12 feet of air between the top of the bed and the top of the crop. This will allow five feet for mechanicals to run above the crops.
It is almost certain that after installing and using prototypes, there will be many improvements that can be applied to the modules. Possibilities include varying the size and depth of the growth bed, increased automation, and improvements of building materials.
There is a fifty foot extension out the north end of the module which holds the various mechanical systems needed by this system. The north end is used to maximize sunlight brought into the system. Projected mechanical systems include:
- Elevators or stairs to move between module levels.
- Air conditioning and ventilation systems to control the module climate.
- Water pipes for irrigation systems.
- Electrical power runs for lighting and protective systems.
Steel reinforced concrete is the building material of choice for these modules due to its ability to handle extreme pressures and temperatures. In addition, the use of concrete also allows the module to have a large thermal mass, which provides for passive solar heating.
Windows in the module can be any number of types depending on the local needs. For example, in the U.S. these windows could be triple layer hurricane and tornado resistant plastic based systems. If that is too expensive, the windows could be simple multilayer glass panels that are covered by a steel door similar to commercial garage doors.
In order to reduce the operating costs of the greenhouse, several systems will be used to recycle naturally occurring elements. Key systems include:
- A rainwater/precipitation harvesting system .
- A geothermal exchange heat pump system to control temperatures .
- A composting system to recycle plant waste into new soil for the modules (basically everything that isn't eaten could be recycled) .
- A "green roof" system that encourages local wildlife to gather, including bees and other pollinating insects.
- Use of "fly ash" and slag from coal burning power plants and iron foundries as concrete aggregate.
- Use of light shelves  to reduce lighting costs.
- Update 6/11/2008: Use prism glass to reflect light into the center of the greenhouse .
Application and Use
After giving this more thought, it seems unlikely that these modules will catch on in the original target zone, Kansas and other states in the Great Plains. However, installing several prototype modules in Kansas would allow the idea to be verified and subject it to a wide variety of environmental extremes. From there, these modules could be customized for deployment in more hostile environments across the U.S., such as Alaska, the Southwestern states, and the Hawaiian Islands. Once those modules have been used and proved in those environments, the plans and techniques could easily be exported to other areas around the world, like the island nations in the Caribbean, parts of Africa, the Canadian Shield, Siberia, India, the Middle East, and Europe.
In each location, it would be better to deploy the plans and skills to allow local industry to implement the design, rather than selling a one-size-fits-all solution. This will allow owners to remove systems they don't need in favor of systems they do need. For example, in the United States and Europe, the cost of labor is high. For these areas, automated farming equipment based on consumer-grade yard care machines and powered by electricity would be an excellent investment. In areas of Africa, India, and the Middle East, however, the cost of labor is low, and in fact having more laborers getting paid a decent wage is a good way to stimulate the local economy. So the automated system would be replaced with a system designed to use a large number of people.
(One key benefit to employing a large number of people in Africa and the Middle East has a more practical benefit to the United States: Farming is hard work. After working in the fields all day long earning money for his family, someone who would otherwise become a terrorist is simply too tired to go out and raise hell. So American, Israeli, or other peacekeeping forces are safer.)
Similarly, areas that are not affected by hurricanes and tornadoes, like Siberia, would not need to deploy the armored window blinds needed in areas like Kansas or Montserrat to protect against tornadoes and volcanic eruptions. Modules located in the Siberian tundra would be more likely to use a simpler system based on standard window blinds to allow plants to grow successfully during the "white nights" so common in that region.
These modules would also be good for reclaiming open pit mines, quarries, and brownfields that are otherwise standing idle. In the Bingham Canyon Mine alone there's room for 1700 modules. If we set them up on the terraces of the mine, we can get some good use out of the otherwise useless land. And the Lavender Pit and El Chino Mine are standing idle in the American Southwest. Make them over into giant greenhouses using the stackable modules.
In addition to the benefits described above, there may be additional environmental benefits derived from the use of the modules. By placing them near a power plant that is fueled by fossil fuels, heat that would normally go to waste could be captured and used to heat the module stack. Carbon dioxide emissions from the power plant could also be reduced by directing some or all of the power plant exhaust into the modules for conversion into oxygen by the food crops. This will require an excellent filtration system however to remove all the various heavy metal pollutants that would otherwise go into the food crops.
Another benefit could be derived from the use of compost. By mixing the exhausted soils found in Africa, the American Southwest, and the Middle East with compost generated for the modules in a 50/50 mix more modules could be put into operation sooner. The exhausted soil would also get a "recharge" from the compost added to it. After a few years this soil should be able to grow crops on its own, and could be given out to local farmers and gardeners.
The compost systems used by the modules should take in all sorts of plant and animal waste. These composting systems could be set up in place of (or in addition to) the local dump, and automatically load the resulting compost into whatever distribution system the modules have installed. This will allow the module stack to convert an otherwise dangerous waste stream into a beneficial product.
Licensing and Development Information
In order to get the ball rolling, I'm releasing this idea under the Creative Commons Attribution 3.0 United States License, the details of which can be found on the license page. In order to save time, the license basically says you (or anyone) can:
- Share-Display, copy, distribute, etc. the work.
- Remix-Make derivative works based on this concept.
AS LONG AS
- Linkback-You provide a link back to this page.
- Give credit where it's due-You say in your work (acknowledgements section, thanks, colophon, etc.) "This work was inspired by an idea from Matt Bear, available on-line at http://www.towerofjade.com/bi/multilevelgreenhouses.html."
Update: 8/28/2008 - Someone's beaten me to it
I just ran across an article in WikiPedia that discusses this very idea, except they call it "Vertical Farming". Apparently there's even an organization devoted to promoting the idea of vertical farming, complete with designs and artit's concepts.
You might think I'd be depressed by this, but the opposite is true: The man behind Vertical Farming is Dickson Despommier, who WikiPedia says "...is a professor of environmental health sciences and microbiology at Columbia University in New York City, New York." So I have, without even realizing it, duplicated a concept that a Ph.D professor created! And without using his sources or inspiration or anything! Whoo-Hoo!
Of course, my idea isn't as grand a concept as his is. After all it's comparitively simple to build a series of boxes that stack together instead of a skyscraper. But then again, maybe my concept is more accessible than his is. Plus there's the whole "crowded urban environment" bias that's automatically built into anything that comes out of New York City. (Not their fault; The residents are tripping all over each other.)
-  See http://en.wikipedia.org/wiki/Rainwater_harvesting
-  See http://en.wikipedia.org/wiki/Geo-exchange, http://en.wikipedia.org/wiki/Geothermal_exchange_heat_pump, and http://en.wikipedia.org/wiki/Geothermal_heat_pump
-  See http://en.wikipedia.org/wiki/Composting
-  See http://livebuilding.queensu.ca/green_features/smart_lighting/light_shelves
- Inspired by a Digital World Tokyo article I saw on Slashdot.org.