TECHNO-ECONOMIC ANALYSIS OF A STAND-ALONE PHOTOVOLTAIC WATER PUMPING SYSTEM FOR RURAL WATER SUPPLY IN THE DEMOCRATIC REPUBLIC OF THE CONGO

Abstract

Access to potable water remains a critical challenge in rural areas of the Democratic Republic of the Congo (DRC). The lack of reliable electricity prevents the use of conventional pumping systems, forcing populations to rely on unsafe water sources. This study focuses on the village of INSTHWEM Mukongo in the Kwilu province, which suffers from a severe lack of clean water. This research presents the techno-economic analysis of a photovoltaic water pumping system designed to meet the community's needs. The methodology is based on field surveys and empirical data collection. Key parameters including population (5,636), water demand (129 m³/day), well characteristics (static level: 30 m, drawdown: 15 m), and solar potential (4.7 kWh/m²/day) were used to dimension a stand-alone system. Hydraulic calculations determined the Total Dynamic Head (HMT), followed by photovoltaic (PV) system sizing, pump selection, and storage tank dimensioning. The economic viability was assessed over a 20-year project life using a discounted cash flow analysis. The analysis resulted in a PV system with a peak power of 9.9 kWc, a Grundfos SP 95-3 pump, and a 285 m³ storage tank. The total investment cost is estimated at 70,400 USD, with annual operation and maintenance costs of 650 USD/year. The Levelized Cost of Water (LCOW) is 0.083 USD/m³, demonstrating that solar pumping is 5.6 times more economical than a generator-based system over its lifespan. The system provides a 10.3% safety margin even during the least favorable month. The study demonstrates that a well-designed photovoltaic pumping system is a technically and economically viable solution for providing reliable access to water in rural DRC. The system offers a sustainable and cost-effective alternative to conventional methods, significantly improving the living conditions of the population. The methodology presented can serve as a reference for similar rural electrification projects in Sub-Saharan Africa.