Comparative life cycle assessment of aquaponics and hydroponics in the Midwestern United States

Abstract

With high productivity and low land and water use, controlled-environment agriculture (CEA) like aquaponics and hydroponics has become a promising solution to feed the rapidly growing global population. However, both aquaponic and hydroponic systems require high energy input, leading to potential environmental burdens. This cradle-to-gate life cycle assessment (LCA), for the first time, compared the environmental performance, on an economic basis, of aquaponics and hydroponics with identical system design in Indiana, US. For a one-month cultivation period, tilapia and six vegetables produced in the aquaponic system had almost twice the total value of the vegetables from the hydroponic system. Aquaponics produced 45% lower endpoint environmental impact than hydroponics. Electricity use for greenhouse heating and lighting, and water pumping and heating contributed to the majority of the environmental impacts of both systems, which was followed by the production of fish feed and fertilizers. However, changing the energy source from coal to wind power could make the hydroponic system more environment-friendly than the aquaponic system. This LCA study can provide CEA farmers with the groundwork to reduce the environmental cost of their production.