A decision-making method based on economic and environmental life cycle analysis for sustainable controlled environment agriculture (CEA) design and operation

Controlled environment agriculture (CEA) grows crops year-round under controlled conditions that include light, temperature, and humidity. CEA provides food resilience, diversifies food sources, offers the ability to grow food even in regions with less favorable climate conditions, and protects crops from dramatically increased natural and anthropogenic disasters. While fast-growing, the CEA industry is grappling with many aspects such as crop choice, consumer markets and trained workforce. The most significant challenge the industry faces, however, is to achieve economic feasibility and ultimately fulfill its environmental sustainability potential. The latter being particularly due to the energy-intensive nature and high carbon footprints of the industry, which also makes it difficult for CEA, especially indoor vertical farms, to be economically feasible.

Life cycle analysis (LCA) methodology has been extensively used to evaluate environmental impact of crop production systems. While LCA provides important advice for bioeconomic policy development, the methodology may not be fully equipped for providing farmers with specific advice on resource allocation within their farms and addressing their specific aims, such as optimal production targets, profitability and financial risk assessment. The bioeconomic model integrates a biological system within a production system which provides farm-level information to an economic model, with all components interacting with each other.

In this study, a decision-making method for CEA was developed integrating both methodologies, namely bioeconomic modelling and environmental life cycle analysis. We compare the economic and environmental performance for a case study using an indoor vertical farm with open-field production throughout their entire life cycles. The 20,000 square foot indoor vertical farm, located in downtown Detroit, utilizes a combination of ebb and flow systems in 7 vertical racking levels to grow a variety of short turn crops: baby greens, microgreens, culinary herbs, and edible flowers.

System boundaries encompass production, packaging, transportation, and retail stages, up to the point of consumption. Using a functional unit of 1 kg of baby greens produced the analysis normalizes input and output flows across both systems. The data collection and calculation procedures adhered to ISO 14044 standards, with inputs and outputs for the life cycle inventory of crop production sourced from databases and bibliographical references. The Ecoinvent Database v3.10 was employed to evaluate environmental impacts across various systems. Insights on profit generating capacity and design of capital structures of CEA farms are obtained from a positive bioeconomic model given the “what if” structure of the integrated decision-making method.