A Multi-Scale Electromagnetic and Hybrid Energy Harvesting Theory for Near-Continuous Portable Power Systems

The growing demand for portable energy in off-grid environments highlights the limitations of conventional battery-based systems, which rely on finite stored energy and periodic recharging. While energy harvesting offers an alternative, existing approaches remain constrained by single-source dependence and low energy density, particularly in electromagnetic (RF) harvesting. This study proposes a multi-scale hybrid energy harvesting theory that integrates solar, kinetic, RF, and micro-scale energy sources within a unified framework. The model is grounded in the principle that energy availability is determined by the time-integrated accumulation of power rather than instantaneous output. A system-level architecture incorporating hybrid storage and adaptive energy management is developed and evaluated through time-domain simulation. Results show that, although individual sources are insufficient independently, their combined effect significantly improves energy stability and extends operational lifetime. The proposed Energy Continuity Principle establishes a pathway toward near-continuous portable power through multi-scale energy integration.