Benchmarking the Efficiency of Stand-Alone Solar Photovoltaic Systems in Nigeria

The growing demand for clean, reliable energy in off-grid and rural areas has made Solar Photovoltaic (PV) systems a viable alternative to conventional power sources; however, maximising their efficiency while balancing cost and reliability remains a significant challenge, especially in developing regions. This study presents a novel, locally engineered Pulse Width Modulation (PWM) Solar charge controller (SCC) designed to enhance energy conversion efficiency in stand-alone PV systems while maintaining affordability and ease of maintenance. Unlike existing studies that rely on imported or commercially available controllers, this research integrates indigenous design optimisation, locally sourced components, and context-specific testing under Nigerian climatic conditions. The locally constructed PWM charge controller was experimentally compared with a foreign PWM and a Maximum Power Point Tracking (MPPT) controller. Results showed that the MPPT controller achieved the highest efficiency (45-77.6%), while the PWM SCC recorded 43-66%. The inverter efficiency reached 89.7%, and the overall system efficiency was 24.4% for MPPT and 17.4% for the local PWM design. Despite its lower efficiency, the locally built PWM controller demonstrated significant potential as a cost-effective and reliable solution for rural electrification, particularly where access to advanced components is limited. The novelty of this study lies in the development and validation of a locally fabricated PWM SCC tailored to regional energy demands and environmental conditions, bridging the gap between performance optimisation and economic feasibility. It also offers a platform for standardising the overall efficiency of stand-alone Solar PV systems while providing practical insights for advancing contextualised renewable energy technologies that promote sustainable, community-driven electrification in Nigeria and similar developing regions.