Parametric Design and Genetic Algorithm Optimization of a Natural Light Stereoscopic Cultivation Frame

Vertical farming (VF) is an emerging cultivation frame that maximizes total plant production. However, the high energy-consuming artificial light sources for plants growing in the lower and middle layers significantly affect the sustainability of the current VF systems. To address the challenges of supplementary lighting energy consumption, this study explored and optimized the structural design of cultivation frames in VF using parametric modeling, a light simulation platform, and a genetic algorithm. The optimal structure was stereoscopic, including four groups of cultivation trough units in the lower layer, two groups in the middle layer, and one group in the upper layer, with a layer height of 685 mm and a spacing of 350 mm between the cultivation trough units. A field experiment demonstrated lettuce in the middle and lower layers yielded 82.9% to 92.6% in the upper layer. The proposed natural light stereoscopic cultivation frame (NLSCF) for VF was demonstrated to be feasible through simulations and on-site lettuce cultivation experiments without supplementary lighting. These findings confirmed that the NLSCF could effectively reduce the energy consumption of supplemental lighting with the ensure of lettuce’s regular growth. Moreover, the designing processes of the cultivation frame may elucidate further research on the enhancement of the sustainability and efficiency of VF systems.