Build your own Vertical Farm - Part 1

For the longest time, I have held a distant fascination with agriculture, from the scale of engineering that goes into the enduring practice of growing things, to the technology that powers such a broad industry today. In more recent years, I have also come to understand the importance of farming in the context of sustainability, and the drivers that determine what we grow, how we grow it, and where it is grown, especially where land usage is one of the biggest factors in determining the severity of anthropogenic climate change.

In this regard, we have seen an increased pressure on farmers to grow differently, such as producing energy crops for biofuels, minimising the use of fertilisers to reduce water pollution, and rewilding unproductive plots in the interest of restoring biodiversity. In some more ambitious cases, this has led to some very exciting innovations, from hydroponics growing plants without soil, to agrivoltaics promoting the mutual benefits of combining solar farms with conventional plant or animal farming.

Similarly, we have seen the format of contemporary farming starting to shift, with urban and micro-farming focusing on high-yield growing in underutilised plots outside of the traditional rural setting, on rooftops, and more topically, stacked vertically indoors. The latter is what we are interested in the most for this project, commonly dubbed vertical farming, we want to explore this most promising of farming technologies, the engineering behind it, how accessible it is now and how scalable it is in the future, using the latest off the shelf components provided by Würth Elektronik, OKdo and RS Pro.

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What is vertical farming, and why is lighting so important?

While there has been a great deal of work and research into more organic methods of improving crop yield density, the concept of vertical farming leans firmly in the opposite direction. Basing its approach on technology and precision engineering, these contemporary farming techniques aim to create optimal growing environments using LED lighting, artificial microclimates, and automated irrigation systems that can be stacked vertically indoors and operate around the clock. This, aside from the obvious gains in crop yields and climate predictability over a much smaller footprint, gives us an exciting glimpse into the potential for how and even where we could grow things in the future.

Vertical farming is an emerging industry with a lot of promise

Like many technological solutions, however, the greatest hindrance to the commercial viability and subsequent growth of vertical farming is the cost of energy. In this respect, we will be collaborating closely with Würth Elektronik on this project, a company that has put a great deal of effort into the development of high-efficacy horticultural LEDs, and where we will also be making good use of their horticultural lighting expertise alongside their range of tailored hardware.

Lighting is the most prominent factor in determining the operating cost and therefore viability of any vertical farm project. As they can potentially operate for twenty-four hours a day, and ultimately affect farm productivity, selecting a highly efficient LED with the correct power and spectrum can mitigate waste energy, improve growth rates, and therefore make a huge difference to the broader adoption of vertical farming in the near future.

Würth Elektronik diagram detailing gains from LED grow lighting

Naturally, as an emerging technology and one that has sustainability credentials, vertical farming is a topic I have been keen to explore for a while now. In this respect, this series of articles will focus on building our own miniature vertical farm system in order to objectively discover its merits on a small scale and more thoroughly understanding the feasibility of implementing this idea on a larger scale.

Parts list

• RS Pro 20mm aluminium profile
• RS Pro right-angle brackets
• RS Pro M5 screws
• RS Pro M5 T-slot nuts
• Laser Cut 5mm plywood

Design Mentality

The principle aim of this project is to test the viability of building a functional small-scale vertical farm with a focus on the core components such as a multi-layer frame, artificial lighting and some level of monitoring and closed-loop automation. The first part of this project therefore, will focus on the building of a two-level frame that will support our plants as they grow one on top of the other, in addition to any electronics and switch gear needed to create the appropriate growing conditions.

Mocking up the frame in DesignSpark Mechanical

The superstructure will be constructed using 20mm aluminium extrusion from RS Pro, while the supporting floors and walls will be constructed using 5mm plywood that will be cut into profiles with a desktop CNC laser cutter. Using DesignSpark Mechanical we can visualise the layout of both the structure and the placement of any supporting structural components like the floors and walls that are sized to hold two standard-sized propagators/grow trays.

Using the CAD model also allows us to predict the optimal location of any grow lights, automation equipment like fans, and any electronic controllers. In this case, we are using an additional third floor to eventually house all of our electronics out of the way and where they won’t get wet.

Building the superstructure

Building the superstructure was a largely straightforward process thanks to the dimensions that we derived from our CAD model. Similarly, we can export the exact profiles of the wooden floors and walls of our structure for use in our laser-cutting software.

Using our CAD model to derive the laser-cutting profiles

Using a circular saw we can cleanly cut the lengths of aluminium profile to size and assemble our superstructure using machine screws, t-slot nuts and right-angle brackets that we got from RS Pro.

The superstructure was designed to be strong, lightweight and adjustable.

Assembling the walls and floors from the different wood profiles

We can then cut our wood to size using the laser, drop the floors in, and then lastly fix any walls and brackets to the aluminium frame using the same screws and t-slot as before. Some adjustment was needed to make sure the LED grow lights we will add in the next article are spaced evenly, but this was straightforward and will ensure consistent plant growth between the two levels.

Conclusion

With the superstructure of our vertical farm now complete, we are ready to start thinking about the actual growing process, and what components we will need to create the optimal conditions for our plants. So far, we have proven that the superstructure can be simple and therefore scalable, so it will be interesting to discover how this compares with the addition of any sensors, actuators and most importantly our LED grow lights (176-6242) and (176-6244) .

Articles in this series:

• Part 1 - Building the Superstructure - (This article).
• Part 2 - Electronics, including lighting and automation.
• Part 3 - Put theory into practice and measure the performance of our system.