Optimal Parameters and Operating Modes of the Vertical Farm Lighting System: an Overview of World Research

Abstract

The vertical farm is a closed system, which is characterized by the most favorable climate with minimal interaction with the external environment. The optimal microclimate of vertical farms provides stable production of dry mass of crops, unlike greenhouses. At higher latitudes, heating greenhouses requires more electricity than lighting. The main task for expanding the geography of the study of vertical farms is to determine the optimal parameters and operating modes of lighting systems in order to minimize the cost of electricity in the production of a unit of production. (Research purpose) The research purpose is reviewing the world research on the optimal parameters and modes of the lighting system of vertical farms. (Materials and methods) Analyzed foreign studies on the use of artificial light sources in crop production for maximum production at minimum cost of purchased electricity. (Results and discussion) It has been shown that with a long photoperiod and low levels of photosynthetic photon flux density, light and electrical energy are used more efficiently within an equal daylight interval. (Conclusions) Based on the results of a review of world studies, it was revealed that a photoperiod of 16 hours a day is necessary for plants to achieve the greatest mass and minimum time spent when growing lettuce, basil, and microgreens. It was determined that the density of photosynthetic photon flux is minimally sufficient when growing microgreens – 100 micromoles per square meter per day (spectrum blue:red:far red light B:R:FR = 20:70:10), lettuce – 200 micromoles per square meter per day (red-blue light R:B = 70:30 and warm white light B:G:R:FR = 8:30:51:11, respectively), the basil has 250 micromoles per square meter per day (blue:red:high red light B:R:FR = 10:80:10).