Hybrid Lighting System for Indoor Crop Production

Lighting systems for indoor crop production facilities face consistency, quality of lighting, and energy efficiency challenges. In this work, these challenges were addressed by developing a natural light collection system that allows sunlight to be concentrated and transmitted via optical conduits into the growing areas of an indoor crop production facility and supplementing it with artificial lighting. The daily light integral (DLI) estimator measures the natural light received while the supplemental lighting provides the additional photosynthetic photon flux to achieve the crop’s lighting requirements. Lux meter and spectrometer characterized the light sensors used to ensure accurate light measurements. The proposed system obtained a mean relative error of 1.78% between the DLI estimator and light instruments. In one testing activity, the system had collected 13.64 mol·m-2·d-1, while the artificial lighting supplemented 6.53 mol·m-2·d-1. The proposed system is vital in maintaining the DLI required by crops throughout the day.