In this study, a techno-economic feasibility analysis of hybrid renewable energy systems for four household categories in rural areas of Chad was studied based on the multi-criteria assessment technique. The problem of this study is to know the best optimal solution in the technical and economic feasibility study of the decentralized mini-grids for the rural electrification of isolated villages in Chad. The main objective of the work is to assess technically, economically and environmentally the feasibility of six scenarios of hybrid systems in five isolated sites in Chad. The performance analysis involved six scenarios of possible hybrid solutions while achieving a supply-demand balance for sustainable electrification of the remote villages, using the HOMER software. The results have shown that the optimum combination of the hybrid system was the photovoltaic/battery system with a Net Present Cost (NPC) of US $ 328,146 and it was found at Etena village. The photovoltaic/Wind/Diesel/Battery hybrid configuration was the least optimum system and it has appeared in Mandelia village. In terms of energy cost, the lowest Levelized Cost of Energy (LCOE) was estimated at US $ 0.236/kWh in a photovoltaic/Wind/Battery configuration at Koundoul site and the highest costs US $ 0.363/kWh in the photovoltaic/Battery configuration at the Linia site. It is established that hybrid solutions can be developed to make electricity available and accessible to the population of the remote rural areas in Chad. However, it is imperative that the local government must subsidize the diesel price to promote the adaptation of the abundant renewable solutions.

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International audienceThis article introduces an original microwave ellipsometry method for the characterization of dielectric materials. It is a non-destructive technique based on the interaction between wave and material in the 26–40 GHz frequency range. The refraction index is obtained by measuring the rotation angle of the refracted wave polarization for different angular positions of the sample. The technique is then validated with polytetrafluoroethylene samples which refraction index is known

The objective of this work is to map the wind resource of two cities of Ndjamena and Faya located respectively in Chadian Sahara and Sahel. As well as the evaluation of the annual energy produced at an altitude of 80m or 100m by the simulation of wind data from wind speed data collected from metrological stations in the Sahara and Sahel areas respectively in the cities of Ndjamena and Faya Airport, and available for five years. In this perspective, we start with the description of the site, the determination of the various wind parameters, such as the mathematical modeling of the wind frequency distribution: Weibull distribution and the numerical simulation of the real wind data collected over five years to provide predictions on sites in two cities of Ndjamena and Faya. Then, we estimate its wind potential, its prediction of the electrical energy produced and we carry out an analysis of the wind turbulence by taking into account the obstacles surrounding near the measurement mast of Ndjamena and Faya, the topography, the roughness of the site, the density and a judicious choice of wind turbines.

In this paper, we reveal the different temperatures recorded in selected magnetic components and, we show the methods of determination and measurement used. As magnetic components have characteristics that strongly depend on the level of local temperature, it is essential to take into consideration the temperature and its influence on the magnetic and electrical characteristics of the component. From the modeling objectives, we describe the constitution, the originality and the main functions of the device used to determine the temperature of the material, its winding, and connection. Finally the result of deepened tests will be presented, allowing to determining parameters of our model. Our work focuses on the development of thermal models capable of determining the working temperature of the chosen magnetic component at given points. It aims to help develop a methodology for designing thermal models of magnetic components; an approach that will be validated through a practical demonstration.