Environmental performance of fruiting vegetable production in vertical farms

Vertical farm (VF) is hailed as a hope for a sustainable food supply system. Fruiting vegetable production is being incentivized in this industry to diversify the product offerings. However, this production model has yet to receive substantive evaluations on environmental performance. This study conducted experiments and employed life cycle assessment (LCA) to evaluate the environmental performance of tomato production in VF, comparing it with tomato production in high-tech greenhouses and lettuce production in VF. The environmental impact of the global warming potential of tomato production in VF was four times higher than that of tomato production in high-tech greenhouse, standing at 22.87 kg-CO 2 eq/kg, primarily due to the energy consumption of lighting. In response to this systemic hotspot, this study evaluated the impact of light emitting diode (LED) technology upgrades and energy choices on the environmental performance of this production model. It was found that both LED efficiency and electricity cleanliness are sensitive factors. Considering Japan's carbon neutrality goals, a shift to renewable energy could reduce the environmental impacts of global warming potential and fossil fuel consumption of tomato production in VF by up to 50 %. Combining LED upgrades with renewable energy could reduce the environmental impacts by 60 %, making tomato production in VF competitive with tomato production in high-tech greenhouse and lettuce production in VF in terms of sustainability. This study highlights the potential of technological improvements and cleaner energy to enhance the environmental performance of fruiting vegetable production in VF.