A new model to evaluate the illumination uniformity of LED plant supplemental light

In recent years, LED-based technologies for flowering light regulation have advanced rapidly. However, there is still a lack of systematic research on the factors affecting illumination uniformity in LED supplemental lighting and their quantitative evaluation. In this study, three key parameters, including divergence angle, vertical distance between light source and illuminated surface, and LED array spacing, were adjusted separately using the control variable method to clarify their quantitative relationship with illumination uniformity. An evaluation model named LED-IUE was established and validated, and sensitivity analysis was performed. The results confirmed the high accuracy of the model and indicated that divergence angle and source–surface distance impose more significant effects. Taking Beijing as an example, the influence of illumination uniformity on greenhouse lighting energy consumption was further investigated. The findings contribute to optimizing flower cultivation, increasing productivity, and reducing energy consumption of supplemental lighting in greenhouses.