Solar-powered multi-port phone charging for rural energy access in Uganda

Reliable mobile-phone charging remains a critical but under-addressed energy-access need in off-grid rural communities, where mobile devices support communication, mobile money, trade, education, health information, and emergency response. This study designed, constructed, and evaluated a low-cost solar-powered multi-port phone charging system intended for rural energy access in Uganda. The prototype integrated a 17 W monocrystalline photovoltaic module, a 12 V/12 Ah deep-cycle lead-acid battery, a 12/24 V MPPT charge controller, DC-DC buck conversion, and five regulated 5 V USB charging outputs. System sizing was based on estimated daily phone-charging demand, photovoltaic energy yield, storage capacity, and simultaneous charging requirements. Under an assumed six peak-sun-hour operating condition, the PV module produced an estimated 102 Wh/day, while the battery provided 144 Wh of stored energy for use during low-sunlight periods or nighttime operation. Prototype testing showed that a feature phone reached approximately 50% charge within one hour, while a smartphone reached approximately 25% within the same period, corresponding to estimated full-charge times of about two hours and four hours, respectively. The system supported simultaneous multi-device charging and demonstrated capacity for approximately 10 feature-phone-equivalent charges per day under favorable sunlight. These findings indicate that a compact, locally adaptable solar charging architecture can provide a practical and scalable solution for improving mobile connectivity in off-grid rural communities. Further field validation across seasonal weather conditions, diverse phone models, and community-use scenarios is recommended to assess long-term durability, user acceptance, and cost-effectiveness.