Techno-economic Analysis of a Small Hydropower Plant for Rural Electrification in Tanzania
DOI:
https://doi.org/10.15377/2409-5818.2025.12.4Keywords:
Tanzania, Ruhuhu River, Small hydropower, Technical performance, Economic performanceAbstract
This study assesses the feasibility of implementing a small-hydropower plant on the Ruhuhu River in Mavanga Village, Njombe Region, Tanzania, with a focus on both technical and economic performance. The technical analysis involved hydrological data (rainfall and flow rates) and field data collected via surveys and interviews. Key parameters included estimated hydropower capacity and civil works such as intake and penstock design. The findings indicate a water flow rate of 71.8 m³/s, power output of 98.67 kW, and a generator specific speed of 434.22 rpm, aligning with the use of a Kaplan turbine. The inlet structure showed a mean velocity of 1.162 m/s across a 3.68 m² trash rack flow area with a 4.28 m³/s flow rate. A penstock diameter of 20.8 cm and a wall thickness of 2.4 mm were determined to be appropriate for the design. In terms of economy, the investment cost was found to reach USD 200,000, with the net present value (NPV) of between USD 286,597.21 and USD 498,510.35 at a discount rate of 4 and 12%. The small hydropower plant demonstrates strong financial viability, with an internal rate of return (IRR) of 25.5%, far above typical discount rates, and a payback period of just 2.32 years, indicating rapid capital recovery. A return on investment (ROI) of 330.6% and a profitability index (PI) of 2.49 further confirm its high profitability and investment appeal. The proposed small-hydropower plant demonstrates both technical feasibility and high economic return, making it a viable solution for enhancing rural electrification in Tanzania. Its successful implementation can serve as a replicable model for other off-grid communities seeking sustainable and cost-effective energy access.
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