Design, construction, and initial testing of a transportable mobile energy station with autonomous solar tracking

This study presents the design, construction, and initial validation of a transportable mobile energy station for off-grid, rural, and emergency power supply. The prototype integrates renewable generation, battery storage, three-phase AC conversion, backup generation, remote monitoring, and autonomous solar tracking on a road-transportable platform. The system combines a 22-module photovoltaic array with a total installed capacity of 6.82 kW, three MPPT charge controllers, a 48 V LiFePO₄ battery bank with 14.4 kWh nominal capacity, three single-phase inverters configured as a three-phase output, and an LPG backup generator. Autonomous positioning of the photovoltaic wings is implemented using a Siemens S7-1215C controller and four LOGO! 8 controllers, which command six linear actuators using astronomical-clock-based solar-position logic, actuator feedback, folded-position switches and emergency-stop protection. Initial commissioning confirmed integrated three-phase power delivery, energy storage, and real-time monitoring through the Victron Remote Management interface. Direct inverter connection initially triggered the battery management system due to capacitor inrush and a 72 Ω pre-charge step resolved the start-up issue. High-current battery wiring was also upgraded after detecting energy losses due to cables heating up. In the first outdoor electric-vehicle charging test, performed under cloudy 6 °C conditions with only the short photovoltaic wings deployed, the station delivered 13.9 kWh over 1 h 15 min through a three-phase Type 2 connection. A representative operating point showed 1.554 kW photovoltaic input against an 11.073 kW charging demand, with the battery bank supplying the deficit while the generator remained off. The results indicate strong potential for application in remote locations, temporary installations, and emergency response scenarios, supporting sustainable and resilient energy systems in future application.