Impact of Hydrology and Financial Cost Analysis on the Production of Mini Hydropower: The Case of Djendjenni, Mali

Abstract

Energy is a central factor that affects society’s living standard and improves people well-being and welfare. It is a pillar of economic development. In order to have sustainable future, the energy production pattern has to be moved towards renewable and sustainable energy. This thesis investigated the pre- feasibility of a potential mini hydropower site, which is located in Djendjenni, Mali. Area rainfall method using rainfall and mean temperature data for the catchment area was used to estimate the discharge. The outcomes of the work reported here indicate that the proposed site has a designed flow of 0.79 m3 /s which is available 90 % through the year and gross head of 20 m. A Kaplan turbine was selected based on the design discharge and the net head. A calculation was made to design the parameters of the turbine for a specific speed of 165 rpm, runner diameter of 0.29 m and runner length of 0.72 m. A 10 pole induction motor was selected as the generator for an estimated size of 156.84 KVA and a rotational speed of 612 rpm. The estimated power produced was 113 kW. The RETScreen model was used to analyze the financial viability of the project. Annual energy production estimated from the model was 837 MWh and the anticipated revenue to be generated is USD 382 187 with the specific costs per installed kW 4206 USD. The initial cost of the project estimated by RETScreen was USD 437,356. From the running RETscreen, the simple payback of the project was 7.4 years and a benefit-cost ratio B-C of 3.68 which make the potential site feasible. The results of this study will serve as a potential feasibility to harness this site and serve as a proposed financing of mini hydropower scheme for rural electrification.