LCA analysis of leaf lettuce production in plant factories in various decarbonization scenarios

Using life cycle assessment (LCA), this study compared the CO₂ emission (CE), measured in kg CO₂ equivalent kg^‑1 marketable leaf lettuce produced in a PFAL (LCA conducted using primary data), in a climate-controlled greenhouse (CCG) and open field agriculture (OFA). This study showed that PFAL CE at 7.48 kg CO₂ equivalent kg^‑1 lettuce was 16 times higher than OFA and 3.8 times higher than CCG. The largest contributor to CE in PFAL was energy-related emissions, followed by structure/capital equipment and chemicals (fertilizer, disinfectant, etc.). In the scenario analysis, it was found that implementing energy efficiency measures and optimizing operations to boost yield at PFAL could reduce CE by 58%, whereas electricity grid decarbonization efforts with most of the generation source being renewable sources could reduce CE by 55%. These 2 efforts could collectively reduce CE by 78% to 1.65. CE parity with OFA can be achieved if PFAL adopts more low carbon energy sources, switch to low embodied carbon building structure, materials, and account for land sparing and afforestation.
This study showed that it is possible for PFAL to achieve net lower CE compared to OFA, while retaining the advantage of land, water, and fertilizer use efficiency.

IV Asian Horticultural Congress – AHC2023

S. Kawabata, Y.C. Lan

carbon footprint, decarbonization, life cycle assessment, plant factory

https://doi.org/10.17660/ActaHortic.2024.1404.178