Harnessing Sunlight for Sustainable Urban Farming: Optimizing Photovoltaics in Tropical Container-based Aquaponics Systems

Currently, Singapore imports more than 90% of the food consumed. In order to be less reliant on external sources, Singapore aims to produce 30% of its nutritional needs by 2030 through alternative spaces for farming such as a Container-based Aquaponics System (CAS). This paper outlines the study into determining the optimal photovoltaics (PV) panel configuration on a CAS, which would ensure optimal daylight passing through and, as a result, allows for the favourable growth of crops. As these container-based aquaponics systems have yet to be implemented locally, the PV panel design of this CAS was studied and developed with reference to overseas case studies. A comprehensive review of the relevant case studies and lighting parameters such as Photosynthetic Photon Flux Density (PPFD) and Daily Lighting Integral (DLI) was performed, followed by a site investigation to examine if the conversion factor is influenced by the climate classification, sky conditions, and sunlight spectrum changes. The modelling process was carried out in Revit and Rhino, whereas the simulation processes were conducted with ClimateStudio. Based on the analysis and comparison of the research findings, the ideal container arrangement and PV installation (involving the transparency rate and tilt angle) that promoted the favourable growth of the crops was then recommended. Through this paper, the benefits of the CAS were studied; it was found that the CAS could increase crop yield towards the goal of food security. The findings from this study can provide a valuable basis for designing container-based aquaponics systems in metropolitan contexts with tropical climates, such as Singapore and other densely populated cities in Southeast Asia. By offering insights into optimizing daylight use and PV panel configurations, this research has the potential to increase the feasibility and efficiency of such systems in these regions. As a result, it contributes to the pursuit of sustainable urban farming and underscores the importance of alternative farming spaces in fostering a more self-reliant and environmentally conscious future.