Sprouting hydro-cities to feed urban communities: are they sustainable?

Hydroponics systems grow plants in a nutrient solution using a growing medium instead of soil, providing an alternative approach to traditional gardening, particularly in urban areas. This study conducted a comprehensive life cycle assessment of hydroponics systems in Chicago to evaluate their potential, identify opportunities for improvements, and assess the benefits across various aspects. The evaluation used an existing hydroponics system in Chicago as a case study to compare a hypothetical scaled version of the hydroponics system and a scaled version of a community garden within the same area, serving the same number of users. Quantitative and semi-quantitative methods were used to assess the sustainability across the triple bottom line: environmental, social, and economic aspects. The environmental impact analysis was performed using life cycle assessment (SimaPro), while the social and economic sustainability were evaluated using a semi-quantitative approach. The results indicate that the hydroponics systems present greater sustainability challenges than community gardens, and the hydroponics system incorporated with LED lights was found to be more sustainable than the community garden. Furthermore, the analysis highlighted opportunities for improvement in hydroponic systems. Future research should assess differences between the two models more accurately in areas not fully captured by the current study.