Off‐Grid Solar Systems: An Experimental Work and Systematic Techno‐Economic Analysis

ABSTRACT This study presents an integrated experimental and techno‐economic analysis of off‐grid solar photovoltaic (PV) systems. A custom data‐logging platform, developed using an ATmega328P microcontroller, was employed to monitor the performance of two 100 W mono‐crystalline PV modules under real outdoor conditions in Zhenjiang, China, from April to August 2023. The logger continuously recorded voltage, current, solar radiation, and temperature with 20‐second resolution, enabling evaluation of operational behavior. Results revealed a strong positive correlation between solar radiation and power output, while higher cell temperatures led to a notable decrease in efficiency. The maximum peak power of 69.55 W and 74.51 W was achieved on 11 July 2023, with the highest efficiencies of 14.65% and 15.98% observed on 15 June 2023. Economic assessments using net present value (NPV) and levelized cost of energy (LCOE) methods showed that a simple DC configuration remains cost‐competitive with the grid (LCOE ≈ ¥0.38/kWh). However, its payback period exceeds 10 years. Conversely, the AC system, which required an inverter, was economically non‐viable under current market conditions. These findings highlight the importance of minimalist design and provide a validated dataset for optimizing low‐cost off‐grid PV applications in similar climate zones.