Proceedings of the International scientific and practical conference ―Multidisciplinary approaches in science, technology and culture‖ (September 5-7, 2025) / Publisher website: www.naukainfo.com. – Oxford, United Kingdom, 2025. - 124 p.

114 toward charging the BESS [2]. If renewable generation is insufficient to cover demand, the BESS is activated to compensate. Once the state of charge drops to a critical level, a diesel generator or other backup source is automatically engaged [7, 2]. When access to the external power grid is available, it may serve as the last level of backup or be used to recharge the batteries in cases where it is economically justified [3, 8]. The backup system is implemented through a series of automated scenarios that are activated by the EMS depending on current operating conditions [1–4, 7]:  Normal Mode (RES-dominant scenario): Full load coverage is provided by photovoltaic panels and/or Wind turbines, with any surplus energy directed to battery charging.  Night or Windless Mode (BESS-dominant scenario): Power is supplied from batteries when RES generation is unavailable; non-critical loads may be disconnected to extend system autonomy.  Critical BESS Level – Generator Start: Automatic activation of the diesel generator when the state of charge drops to 20–25%, supplying the load and recharging the battery.  Peak Load Mode (Joint Generation Scenario): Simultaneous operation of RES, BESS, and backup generators during periods of maximum demand.  Emergency Backup Mode (Isolated Reserve Scenario): Critical loads are powered by the generator or batteries in case of failure of key components or overload of the internal network. This multi-tiered backup logic maintains power supply reliability under various operating modes, while minimizing fuel consumption and ensuring high overall energy efficiency [2, 7]. A hybrid system with a clear source hierarchy and EMS control delivers continuity and cost-efficiency: prioritize RES → charge BESS → cover deficit from BESS → auto-start backup only at critical state of charge, with the grid as the last tier or for economically justified charging. This cuts fuel use, equipment wear, raises the RES share, and lowers the carbon footprint.