Reducing the energy footprint and enhancing the flexibility of indoor growing systems while maintaining a high growth rate: Examination of disruptive cultivation protocols

Nowadays, one of the main challenges is to bring safe, fresh and nutritious food in the rapidly growing urban areas. Vertical farms (VFs) is a pioneering agricultural method that can significantly contribute in the partial solution of this challenge. Due to the sophisticated controlled-environment agriculture, the fully insulated installations and the application of multiple stacked growing layers, VFs provide 5-7 times greater yields per unit area. However, one of the main challenges of VFs is the high electricity demand for artificial lighting operation and consequently high operational cost for achieving and maintaining maximum biomass production in a year round basis. The aim of this study is to examine and determine the specific operation hours via intermittent lighting operation that will help VFs reduce their operational cost and at the same time maintain or even maximize their yield production in cherry tomato plants. Continuous and intermittent intervals of lighting operation were tested in indoor controlled environment growth chambers. Results showed that under a 15-h intermittent photoperiod, cherry tomato plants had a positive response with increased fruit formation and yield production compare to a 16-h continuous photoperiod. The electricity consumption was 22.7% reduced under the stress treatment compare to the control one, due to the one hour reduced photoperiod. This study shows that intermittent irradiation schedules can increase the flexibility in lighting operation inside VFs while simultaneously support the grid and the local production industry with a more ecological, sustainable and economic impact in terms of energy footprint.