Synergistic Design and Optimization of a Solar-Harvesting Energy Storage System with High-Efficiency Resonant Inductive Power Transfer

Integrating renewable energy harvesting with wireless power transfer (WPT) introduces complex multi-physics coupling challenges, primarily regarding thermal detuning and conversion inefficiencies within compact enclosures. This study proposes an optimized architecture and analytical framework for a Solar-Driven Portable Energy Storage System (SPESS) that bridges the gap between solar harvesting and autonomous wireless delivery. The system integrates a high-efficiency 5 V monocrystalline photovoltaic (PV) array with a 10,000 mAh lithium-ion core, regulated by an adaptive Maximum Power Point Tracking (MPPT) algorithm. We formalize the synergistic coupling between thermal and electrical subsystems, demonstrating how iterative thermal–electric co-design—utilizing CFD-modeled ventilation and anisotropic graphite spreaders—effectively suppresses capacitive drift in the resonant network. Unlike fixed-frequency chargers, this design employs Phase-Locked Loop (PLL) frequency stabilization to maintain a “High-Q” state, achieving wireless transmission efficiencies exceeding 85% and a measured 12.3% restorative gain in the WPT stage compared to a thermally detuned baseline. Robustness analysis confirms spatial resilience up to 10 mm of lateral misalignment and thermal stabilization at 48 °C under continuous 15 W load, contributing to a calculated 18% extension in battery cycle life via suppressed chemical degradation. Experimental validation across varying irradiance levels (100–1200 W/m2) demonstrates a full recovery cycle of 23.6 cumulative solar hours at Standard Test Conditions (STC). This research provides a scalable, theoretically grounded framework for resilient, self-sustaining energy modules for disaster relief, remote education, and mobile health applications.