Optimization of System Efficiency and Energy Management in a Low-Voltage DC Solar Generator

ABSTRACT

The growing demand for sustainable and decentralized energy solutions has made low-voltage DC solar generators critical for rural electrification, backup systems, and small-scale applications. This study focuses on the optimization of system efficiency and energy management in a 12 V low-voltage DC solar generator designed and tested under real operating conditions in Ikot Ekpene, Akwa Ibom State, Nigeria. The system integrates photovoltaic modules, an MPPT-based charge controller, lithium-ion storage, and DC-compatible loads, with performance monitored under varying irradiance. Results reveal that while the PV array is rated at 370 W, real-world derating and conversion losses reduce usable AC power to approximately 253 W, highlighting the gap between nominal and effective capacity. Comparative analysis of series and parallel array configurations shows that system design choices directly influence wiring losses, controller limits, and overall reliability. Battery storage proved essential in bridging the gap between peak demand and intermittent solar generation, with runtime analysis confirming its critical role in sustaining system loads. Furthermore, PV power gain analysis demonstrated that maximum energy harvest occurs at midday, though efficiency declines slightly at high irradiance due to thermal effects. The findings underscore the importance of intelligent energy management strategies such as load prioritization, optimized battery cycling, and predictive control in maximizing usable output. This study concludes that with proper system optimization, low-voltage DC solar generators can provide reliable, sustainable, and cost-effective energy for small- to medium-scale applications, advancing Nigeria’s renewable energy transition and improving energy access in underserved regions.

Keywords: Low-voltage DC solar generator, photovoltaic systems, energy management, system optimization, MPPT, battery storage