This work presents a hybrid renewable energy system designed for agri-industrial applications, integrating photovoltaic~(PV) generation, lithium iron phosphate~(LFP) battery storage, and hydrogen production through water electrolysis. The proposed architecture is intended to support decentralized agricultural energy systems characterized by variable electrical demand, intermittent renewable availability, and the need for both short-term and seasonal energy storage solutions. The system is developed in MATLAB/Simulink and validated under realistic climatic conditions using hourly meteorological datasets, including global horizontal irradiance~(GHI), direct normal irradiance~(DNI), diffuse horizontal irradiance~(DHI), and ambient temperature. Three Italian locations are considered: Rome, Catania, and Turin in order to investigate the influence of different climatic and solar resource conditions along a representative north-to-south gradient. The PV subsystem is modelled through a temperature-dependent efficiency formulation, while the battery pack behaviour is represented using a second-order equivalent circuit~(2RC) capable of reproducing transient voltage response and state-of-charge dynamics under variable operating conditions. An energy management strategy is implemented to prioritize direct electrical consumption and battery charging, while surplus renewable electricity is diverted to the electrolyzer for on-site green hydrogen production. The hydrogen subsystem therefore acts as an additional long-term storage pathway, enabling improved renewable energy utilization and reducing excess energy curtailment during periods of high solar availability. A full-factorial Design of Experiments~(DoE) is carried out by varying PV installation area and operating location, generating annual simulation scenarios and allowing systematic comparison of system behaviour under different configurations. The analysis focuses on renewable energy utilization, battery operation, hydrogen production potential, and overall system flexibility. The proposed simulation framework represents a scalable and practical pre-design methodology for supporting the development of sustainable agri-industrial energy systems. It can assist decision-makers in identifying suitable component sizing, geographic deployment strategies, and operational configurations capable of increasing renewable penetration while improving energy autonomy in agricultural contexts.