This is where the measurable chaos began... 2012, my junior year of undergrad, studying landscape contracting after completing an internship with a larger commercial maintenance firm. The internship was a decent experience but the idea of burning oil and gas 5 days a week just for the sake of making properties look nice was not at all fulfilling. Because of this, I knew I had to pursue a different path. I decided to give an independent study a try with a professor who was an expert in green roof technology. That seemed more what I was looking for; integrating nature into the urban world in a practical and functional way. The independent study was interesting and I learned quite a bit about green roof technology. One day I heard a speaker discuss vertical farming and the idea of growing crops in skyscrapers. In my mind, I thought, "Wow, that would be incredible to bring to life." I was skeptical though; you always have to wonder that if something is such a great idea and has so much potential, why is it not in existence yet?" Sure enough I went back to my professor and talked about the concept of vertical farming. His response was quite simple; "it is cool but also inefficient and even more expensive. You can't drive a tractor up a wall either..."
Dr. Rob Berghage giving a guest lecture on one of the Penn State green roofs
So that's where it began... "Alright, sure you can't drive a tractor up a wall, but what if there was a type of 'farming infrastructure' that allowed crops to be grown on a vertical plane with a much easier means of maintenance?" Maybe there is some possibility for this concept with some re-thinking. I did some research and learned that green-walls (a basic frame with hardware for growing plants on a wall) were actually a thing, but were also purely aesthetic. "Again, can we get away from the whole aesthetics-only thinking?" At that point, I began to realize that the only way to make this practical would be through the integration of a moving plane. That lead to the concept of a shelf structure which incorporated a container throughout each level for growing. The shelf would then move up and down on a track so maintenance could be made possible at an arm's reach. Alright, that's great, but if this was to be anchored on a side of a building or some other structure, the entire plane would have to traverse underground; there goes the practical aspect again... Then it hit me, "it doesn't have to go underground if it goes back up and around; what if circular motion was part of this whole concept?" That's when I thought about a carnival ride called "The Zipper". If I kept the conveyor system stationary along a building's surface and the carriages kept consistent orientation; that's really what would make this work; essentially a mix of "The Zipper" and a Ferris Wheel.
I drew up a design that night and then made a 3D model in Google SketchUp. I was excited and my professor was interested as well; telling me that I could take another independent study to build it. I didn't at to wait that long so the construction phase took place that summer...
That's what I needed to build...Go!
Although impractical; this would be an incredible site...
This is where my lumberyard and hardware store background came in. I knew if this project was going to take place in a greenhouse I was going to need the right materials to take the environment; which meant a lot of water, sun, and heat. I started taking materials home each day after work; pressure-treated 2x4s, zinc plated rods, wheelbarrow wheels, PVC pipe, gutter, deck screws, and galvanized chain and eye-bolts. After a while I had the basic frames assembled.
Every component of the prototype consists of readily sourced parts
After being disassembled, the conveyor was taken down to the Penn State greenhouses and then re-assembled. It did rotate, but the better question to be asked was if it could actually grow plants. After some trial and error, it was shown that it absolutely could...
On the left conveyor is a variety of cherry tomatoes and on the right you'll see basil and lettuce.
After a semester of operation in the fall of 2012, I decided to incorporate LED lighting into the next set of growing trials; it performed incredibly well as you can see below. By the spring semester 2013 I had secured my position as a graduate student for the following academic year where I could continue researching what I was in the very beginning stages of developing.
The purple glow in this shot is a result of the red and blue LED plant lighting. Seeing this greenhouse section at night was quite a scene! In this growing trial, there's thyme, basil, spinach, parsley, and a really small variety of cherry tomatoes called micro-toms!
More automation was introduced for the trials that took place in fall of 2013 and incorporated an electric wheelchair motor with a timer to produce controlled rotational intervals.
'Sulu' lettuce was grown for this trial to understand the production differences between a flat and vertical growing surface.
As I got closer to the proposal meeting with my committee for my master's research, I began to realize that for the number of factors I wanted to test, a more extensive experimental setup was needed... I felt like I was in the movie JAWS, "We're gonna' need a bigger boat..." After a few calculations I determined that four wall systems were needed along with the equivalent growing space laid out on benches. That's when hardware mode took over and I split the original conveyor system in two to get what you see below.
There it was; the base rotating living wall unit in what would eventually become my greenhouse section. Three more would be built along with the bench-top units. I think I set a record for the amount of hardware that was ever used in a single greenhouse section that year.
Gutter, bicycle wheels, wheelbarrow wheels, chain, wood, and cinderblocks
By the end of May, the entire experimental setup was completed and trials began on June 1st, 2014. The entire project incorporated 96 grow troughs, 12 varieties of micro-greens, LED lighting, and an oscillating grow bench. Sixteen trials were completed throughout the year and required 5 hours for seeding and five hours to harvest. To make the setup and tear-down of these trials possible, I created a custom vacuum seeder as well as an automated harvest station.
From beginning of concept to where the Rotating Living Wall is now has been four years in the making. To me this entire experience has been extremely rewarding from the fact that this didn't happen overnight, and there were so many challenges. Some took days and weeks to overcome where I was standing in the greenhouse workshop for hours on end trying to come up with solutions. There were a lot of times where I felt like Dr. House trying to solve a case that had no chance of ever being solved. By the time the entire experimental setup had been constructed, I felt as though my research and my program were accurate reflections of myself; my insight, creativity, hard work, and perseverance. I learned more from that experience than I ever had from inside a classroom. You learn by doing and that's the damn truth. The main take away message I can say is that if you're going to put in 90 hour weeks at times; make sure you enjoy what you do and make sure you have good people supporting you. Otherwise your life will turn to hell quick. On a final note, what you get out of life is what you put into it. Make sure you put your best foot forward and you won't be disappointed.
I will never forget that greenhouse...
