Impact of Setpoint Control on Indoor Greenhouse Climate Modeling

Greenhouse agriculture is a crucial solution to global food security and sustainability challenges, as it provides a controlled environment for plant growth, resulting in higher yields and efficient resource utilization. Climate control plays a critical role in determining energy consumption and plant growth within greenhouse systems. The selection and optimization of control parameters have a significant impact on the overall performance. This study conducted simulations of a tomato greenhouse located in Montreal, Canada, with the aim of evaluating the effect of different control setpoints in the presence of high-pressure sodium (HPS) supplemental lighting and light-emitting diode (LED) supplemental lighting on greenhouse performance. To comprehensively assess the influence of each control setpoint, a sensitivity analysis (SA) was performed, systematically varying the control setpoints over a wider range than what is typically observed in tomato production. The SA utilized different control setpoints as inputs, while energy consumption and crop yield were considered as outputs. The setpoints for relative humidity and air temperature during the light period were identified as the most influential factors. This highlights the importance of accurate measurements and predictions of temperature and humidity to optimize environmental conditions in indoor greenhouses when implementing a predictive control strategy. The results obtained from this SA can contribute to the development of reduced-order models that focus on the most influential variables.