Analyzing the environmental sustainability of an urban vertical hydroponic system

Abstract: Food systems are considered one of the most important anthropogenic activities contributing to climate change. On the other hand, climate change influences the conditions for growth with more frequent droughts and heatwaves. This contradiction poses a significant challenge to future food systems, which need not only become more sustainable, but also increase its production to feed a growing population, as stated in both the United Nations Sustainable Development Goals, and the Swedish action plan on food. This has given rise to alternative ways of producing food, such as urban farming and, in particular vertical hydroponic farming, where food is grown indoors in a controlled environment with artificial lighting and with a minimum use of water and without pesticides. In this study, a vertical hydroponic farm located in Stockholm, Sweden, is examined using life cycle assessment in terms of environmental sustainability. The farm, located in a basement space, works together with the building in a symbiotic network, where the farm provides the building with excess heat from the lighting, and in turn obtains carbon dioxide from an office floor. The findings from the study show that electricity is a major contributor to the environmental performance of the farm, along with the infrastructure employed. The impacts of water use in the farm, is very low, along with the impacts associated with the delivery of the crops; illustrating the advantages of producing food locally. By substituting the synthetic fertilizers employed to biofertilizers, and by substituting the plastic bag material to renewable material, reductions in greenhouse gases are possible. The symbiotic development between the farm and the building is shown very beneficial to the farm, highlighting the importance of synergies between actors in urban areas.