Possibility of Installing a Mini hydropower plant on Behr- Elgebel River

Abstract

This thesis demonstrates an attempt to develop a new hydropower scheme in the vicinity of Juba city which is so called Juba barrage .The research is directed towards technical and economical feasibility study through two phases, namely desktop and pre- feasibility studies. Hydraulic and hydrological analysis performed and reveals that it is possible to construct a low head hydropower plant just up stream juba city, the proposed total design discharge is 1400 m3/s, corresponding to the mean annual runoff of the proposed site, and the rated head is 7.32 m, annual energy output estimated and will be noted in the next paragraphs. A proposal of a new methodology for determining the optimum number of units for the installation presented which are nine units. The envisaged possible lay out of the plant, is to build a power house across the stream integrated with low head dam or barrage for accommodating the turbine units. . The low head dam is intended to create the required head to drive the turbines rather than to store water. The plant is proposed to produce 83MW as installed capacity with dependable capacity of about 60 MW, the annual energy generation is estimated at 549GWh.The study proposed a bulb Kaplan turbine of double regulation type. Anew methodology for predicting its efficiency is presented. The runner diameter being calculated is 4.8 m, running at 115.4 rpm and the corresponding specific speed is 919.33. The total cost including civil works and hydro mechanical and electrical equipments is 423,000,000 USD; the internal rate of return is about 18.1% The negative environmental impact is negligible, since the project is planned to be run- of- river project with no storage capability. In addition to intangible benefits the project will offer jobs opportunities and enhancing the economical status of the inhabitants, the project will contribute in green house gasses GHG emission reduction of 335,446 ton of co2 annually.