S08 - Session P6 - Plant factories energy optimization strategies: a case study in the Mediterranean climate

Authors: Giacomo Scarascia-Mugnozza *, Luigia Mandriota, Ileana Blanco

The Plant factories with artificial lighting (PFAL) guarantee healthy vegetable food production all year round, but they consume conspicuous amounts of energy for environmental heating and cooling and even more for artificial lighting. This work aims to achieve the energy optimization of the production environment of these factories, from an environmental sustainability point of view. Purpose of the research is the proposal of a simulation for the reuse of an existing abandoned building for the installation of a Plant Factory, requiring functional and energy upgrading. The building, chosen as a model of Plant Factory for the cultivation, harvesting and storage of fresh-cut leafy vegetables and herbs in Mediterranean climate, is located in the town of Monopoli, southern Italy. The plants grow by means of soilless culture technologies, lay out vertically on a multi-level rack system, using inorganic substrates and sophisticated fertigation systems. In order to obtain a nearly zero energy building (nZEB), several energy retrofit solutions are analyzed and compared, focusing on the building envelope thermal performance enhancement and the energy production from renewable sources. Several high-performance envelope buildings solutions are implemented and compared to increase the building envelope thermal insulation and thermal inertia. The HVAC system is ensured by means of the biomass-based tri-generation system, used in combination, or alternatively, with the integrated geothermal heating and cooling system. The energy power required for the LED lighting system is supplied by means of the photovoltaic generator, installed on the building envelope and in the factory area, used in combination with the urban grid and the tri-generation system. The holistic predictive evaluations of energy efficiency and saving are carried out employing dynamic energy simulations, comparing the summer regime with the winter one, as well as the day and night variations. The proposed improvement solutions are analyzed through Building Energy Simulation software.