A cradle-to-customer life cycle assessment case study of UK vertical farming

Global population rise, increased rural to urban migration, climate change and conflict have placed strain on global trade and food supply chains. Vertical farming (VF) is a relatively novel method for cultivating many fresh fruits and vegetables, and often is claimed to have lower environmental impacts than field cultivation. However, to date there are few studies utilising primary data which have evaluated the environmental impact VF may have. This study utilised Life Cycle Assessment (LCA) to evaluate the environmental impact of lettuce production in a commercial vertical farm in the UK. This was compared with data from the literature on the impacts of lettuce in field cultivation. Scenarios were also examined to evaluate the impact of VF systems with varying electricity sources, and waste, water and nutrient management options. The VF was found to have a similar or lower Climate Change impact than field cultivation, depending on energy source used. VF had a slightly higher environmental impact than field cultivation in some other environmental impact categories such as freshwater eutrophication potential and acidification potential. Electricity demand and the medium used for 'plugs' in the VF were found to be the main hotspots of the system. The results of this study provide insights on the environmental impact and resource efficiency of VF, feasibility for larger scale deployment, and provide further empirical evidence to support the claims made previously in the literature.