Lee, Y. Y., Yik, J., Koay, E. H. H., & Lau, H. H. (2023). Application of light redirecting panels to improve sunlight utilization in multi-tiered vertical farming systems. Clean Technologies and Environmental Policy. https://doi.org/10.1007/s10098-023-02617-w
Abstract:
Vertical farming systems (VFSs) can intensify food production in urban centers. Multi-tiered grow racks (MTGR) consisting of a series of horizontal grow beds stacked one atop the other is one common type of VFS. When such systems are used on rooftops or in greenhouses where free sunlight is abundant, lower platforms of MTGR are unable to tap on the available sunlight efficiently because the opaque top layers of the MTGR often block incoming sunlight from reaching the lower layers. Thus, photosynthetically active radiation (PAR) at shaded regions of lower layers in MTGRs will be insufficient and nonuniform. A direct solution is to use artificial lighting at lower beds to improve PAR availability. However, this solution is not ideal, as electricity consumption due to artificial lighting can increase monetary costs and indirect carbon footprint. Here, we designed and developed light redirecting panels that can redirect sunlight from the edge of the racks, where sunlight is more accessible, toward the central regions where shading is more severe. In our study, the panels redistributed excess sunlight and improved the cumulative PAR across the central region of the lower platform by 2.6–7.2%. If common leafy greens such as Brassica rapa var. parachinensis (choy sum) and Lactuca sativa (lettuce) are grown, we predicted that our panels can improve photosynthetic activity by up to 10 and 12%, respectively. By harnessing more sunlight in the environment, the solution has the potential to improve crop yield and reduce the need for electrical lighting, lessening the impact of vertical farming on global warming.
License type:
Publisher Copyright
Funding Info:
This research / project is supported by the A*STAR - IAF-PP Sustainable Hybrid Lighting System for Controlled Environment Agriculture Programme
Grant Reference no. : A19D9a0096
Description:
This version of the article has been accepted for publication, after peer review and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s10098-023-02617-w