FeedBack is a reflections blog authored by Arrell Scholars and Ontario Agri-Food Innovation Alliance – Food from Thought HQP Scholars on their experiences in the program. Rosemary Brockett is an Environmental Studies MSc student.

Vertical farms grow produce hydroponically under LED lights in stacked layers in highly regulated indoor environments. The method originated in Japan and has gained popularity around the world with advances in LED technology. Interest is also growing in the ways vertical farming can reduce the transportation, water consumption, and pesticide and land use of industrial farming practices.

However, vertical farming can sometimes get a bad reputation because of the vast amounts of electricity consumed by the LED lights that replace sunlight. For some, this leads them to discount the industry all together. But this can simplify the picture too much, as we learned this year in the agri-food innovation course run by Arrell Food Institute.

What can vertical farms contribute to our food future?

Here in Guelph, GoodLeaf Farms is a vertical farm growing leafy greens that are fresh, nutritious, and hyper-local. GoodLeaf was our community partner for the project, and they taught us a lot about the value of vertical farms. We learned that vertical farms grow food more efficiently by optimizing the growth environment, while reducing fertilizer use and eliminating pesticides. And because vertical farms are impervious to weather, they also have significant potential in the coming decades as a tool to address food security in regions that are too dry or cold to grow food.

Why is renewable energy so important for this sector?

For our project, GoodLeaf asked us to evaluate and compare the environmental impact of their operations to industrial farms and identify opportunities for improvement. Through our work (with Rosemary, the group included Michael Pupulin, MSc in Mathematics and Statistics; Leonardo de Melo, PhD in Mechanical Engineering; and Mylene Corzo Lopez, PhD in Plant Agriculture), we found that GoodLeaf’s land and water use were incredibly efficient compared to other farm operations. But, unsurprisingly, greenhouse gas (GHG) emissions were more of a problem. While GoodLeaf makes remarkable reductions in transportation distances, the electricity use of LED lights pushes GHG emissions up.

The good news is we found that if the electrical grid uses lower carbon energy sources, such as hydro-electric and nuclear, GHG emissions are comparable to outdoor farms, and not more, as is often assumed. However, because we are faced with a climate emergency, this means we need to do more than the status quo.

Our research showed us that the industry must focus on using renewable energy if vertical farms are going to be one of the important tools in our kit for addressing the sustainability and availability of food in the coming decades. In fact, many vertical farming companies are already making the switch. And new technologies are making carbon neutral vertical farming possible, such as solar panels that use waste LED light , co-generation systems for power and HVAC, and integration with other infrastructure.

If the vertical farming industry can make this switch to renewable energy in the coming decades, they will unquestionably outcompete outdoor farms on ALL sustainability metrics.

References

Great Northern Hydroponics. (n.d.). Soave Cogeneration. https://www.greatnorthern.farm/cogeneration/

Kozai, Niu, G., & Takagaki, M. (2020). Plant factory: An indoor vertical farming system for efficient quality food production (Second edition.). Elsevier Science & Technology.

Thilak Raj, N., Iniyan, S., & Goic, R. (2011). A review of renewable energy based cogeneration technologies. Renewable and Sustainable Energy Reviews, 15(8), 3640-3648. https://doi.org/10.1016/j.rser.2011.06.003.

Vertical farming. (n.d.). Elements of Earth and Energy. https://calleee.com/vertical-farming/