According to the International Energy Agency 2016 statistics, Ethiopia is among the lowest countries in annual electricity consumption, 70 KWh/capita. Rural areas hold more than 80% of the country’s population and less than 30% of them have been electrified. Most of the population (the rural areas) still predominantly depend on traditional biomass energy sources for cooking and heating, and household lights are provided mainly by kerosene and biomass including this study area, Tadacha Rarasa, which consist of 4100 households with 6 members, totally 24,600 people[1, 2]. The feasibility study of hybrid system consisting of small Hydro, PV, Wind and Battery is carried out using HOMER as a tool for optimization and sensitivity analysis. TURBNPRO software also assists for the optimization of the small hydropower which is suggested to utilize the 2.2 m3/s ecological flow of the Genale 3 multipurpose hydropower plant’s reservoir. The wind speed and solar radiation data of the site is collected from NASA. Then, the wind speed, solar radiation, electric load and hydro data is input to HOMER in their respective appropriate format for simulation and analysis of the proposed hybrid system.  Electric loads of the community is estimated bearing in mind the irrigation, fishery and other opportunities which will arise after the multipurpose project completion in addition to basic household demands. The daily average estimated residential consumption by each family is 9.118 kWh and the daily average total energy consumption per person is 1.872 kWh.   After optimization and sensitivity analysis using HOMER, several different feasible configurations of Hydro, PV, Wind and Battery hybrid system has been displayed with a range of 0.049 to 0.067 $/kWh cost of energy. The optimum configuration becomes Hydro/PV/Battery hybrid system with 0.049 $/kWh levelized COE which is closer to the national energy tariff, 0.032 USD/kWh. The optimum Hydro/PV/Battery hybrid system generates annually 18,647,372 kWh with 0.18% capacity shortage and 0.15% unmet load. The hydropower supports the base load and the PV supplies for the peak load demand in the daytime which shares 19% of the total electric production.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Foi implementado, na linguagem Visual Basic 6, um programa computacional para a anÃlise do Golpe de ArÃete em adutoras, utilizando-se do MÃtodo das CaracterÃsticas e das equaÃÃes caracterÃsticas de equipamentos normalmente encontrados nos sistemas hidrÃulicos. Procurou-se desenvolver um aplicativo que possibilite ao usuÃrio visualizar o comportamento das ondas de sobrepressÃo e subpressÃo decorrentes do fenÃmeno transitÃrio, alÃm de verificar a influÃncia da chaminà de equilÃbrio e do tanque de alimentaÃÃo unidirecional (TAU) como dispositivos de alÃvio do golpe de arÃete. Aplicou-se o modelo computacional na anÃlise dos transientes hidrÃulicos gerados pelo desligamento do conjunto moto-bomba, e na avaliaÃÃo da eficiÃncia da chaminà de equilÃbrio e do tanque de alimentaÃÃo unidirecional como mecanismos de atenuaÃÃo dos picos de pressÃo. A validaÃÃo do modelo se deu atravÃs da comparaÃÃo dos resultados das simulaÃÃes com os dados obtidos nos testes realizados utilizando-se o CTran, software desenvolvido pela FundaÃÃo Centro TecnolÃgico de HidrÃulica da Escola PolitÃcnica da Universidade de SÃo Paulo. De acordo com a anÃlise estatÃstica, o programa desenvolvido apresentou resultados bastante satisfatÃrios na anÃlise do golpe de arÃete, possuindo uma interface de fÃcil utilizaÃÃo e visualizaÃÃo dos resultados, fato de fundamental importÃncia para que projetistas e estudantes compreendam o comportamento do fenÃmeno. / The main goal of this research is the development of the computer code designed to model the water hammer problem which occurs in water pipes. It was used the method of characteristics to numerically solve the differential equations which control the problem. The software developed allows the user to visualize the behavior oh the over and under pressure waves resulting from the occurrence of the transient problem. Other features of the developed software includes the possibility of analyzing the introduction of mechanisms to decrease the effects of the water hammer problem such as orifice tanks, one-way tanks, closed tanks and relief valves. The developed model was applied and validated to water conducts which was previously been analyzed by the software CTran, developed by the âEscola PolitÃcnica de Universidade de SÃo Pauloâ. The results were very satisfactory