• Energy Research

Abstract The development of renewable electricity in Africa could be massive in coming decades, as a response to the rapid rising electricity demand while complying with the Paris Agreements. This study shows that in the high-resolution climate experiments of CORDEX-AFRICA, the annual mean solar potential is expected to decrease on average by 4% over most of the continent by the end of the century, reaching up to 6% over the Horn of Africa, as a direct result of decrease in solar radiation and increase in air surface temperature. These projections are associated with large uncertainties, in particular over the Sahel and the elevated terrains of eastern Africa. While the expected decrease may affect the sizing of the numerous solar projects planned in Africa for the next decades, this study suggests that it does not endanger their viability. At last, this study indicates that the design of such projects also needs to account for the non-negligible uncertainties associated with the resource.

AbstractThe objective of this paper is to propose a methodology for designing a stand-alone hybrid PV/wind/diesel/battery minimizing the Levelized Cost of Energy (LCE) and the CO2 emission using genetic algorithm. The methodology developed was applied using solar radiation, temperature and wind speed data, collected on the site of Gandon, located in the northwestern of Senegal. Obtained results were presented as optimal Pareto front. The optimal number of devices, the Levelized Cost of Energy (LCE) and the CO2 emission were determined for each solution. An influence study of the size of diesel generator on the optimal configuration was carried.

Photovoltaic research is oriented more and further towards study on PV modules degradation. The objective is to understand the different degradation modes of PV modules and associated factors. This paper presents a platform for measures dedicated to do a study related to degradation of electrical characteristics of the photovoltaic modules. It is installed on the site at University of Dakar in Senegal. This work proposes a method for standardization of the direct measures of the short-circuit current (Isc) and the open-circuit voltage (Voc) of PV modules. The approach used for the assessment of degradation of Isc and Voc involves a comparison between baseline values given by manufacturer and those measured in real operating conditions brought back in the standard test conditions (STC). Findings presented on degradation of Isc and Voc photovoltaic modules cover the first ten months of measurements from Mars to January. Degradation of short-circuit current is about 13% for the three days. The degradation of open-circuit voltage measured during the three days is 8%.

AbstractThe aim of this paper is to determine the wind energy potential for electricity generation in the northwestern coast of Senegal. The wind characteristics and wind energy potential in eight sites (Kayar, Potou, Gandon, Sakhor, Sine Moussa Abdou, Botla, Dara Andal and Nguebeul) are analyzed using the wind speed data collected during a period of one year for each site. The annual mean wind speed and the power density were computed. Results obtained show that the annual mean wind speed varies between 5.28 m/s in Potou (at 30 m) and 3.10 m/s in Dara Andal (at 7 m). The corresponding power density varies between 120.01W/m2 and 30.05W/m2 respectively.A technical assessment of electricity generation from three big wind turbines and from three small wind turbines was carried out. Results show that the highest capacity factor was 39% observed in Sokhar for the wind turbine Yellow- Sand, whereas the lowest capacity factor was 5% in Gandon for the wind turbine Ecotecnia 80. The highest output energy was 4,517,900k Wh/year in Sokhar for the wind turbine Repower, while the lowest output energy was 312 kWh/year observed in Gandon for the wind turbine Inclin 600.

The main target of this paper is to determine the seasonal features of the wind speed in the northwestern of Senegal and to assess the cost of annual energy output using wind turbines provided from several manufactures. The wind data used for this study were collected in four sites located in the northwestern coast of Senegal and cover the period of one year. The seasonal mean wind speed and the annual distribution curves were obtained by using the Weibull distribution function. A technical assessment of electricity generation from five big wind turbines which power is between 640 kW and 2000 kW and from six small wind turbines which power is between 250 W and 10 kW were carried out. The results obtained show that the lower cost (0.0265 €/kWh in Sokhar) was observed for the wind turbine Ecotècnia 62. The highest cost was 0.5103 €/kWh (in Gandon) observed for the technology of Alize. All wind turbines was better suited to the site of Sokhar with the highest capacity factor and the lowest cost of output energy.

This paper is aimed at determining the diurnal characteristics of the wind potential inSenegal. The data used in this study are collected from eight sites (Kayar, Potou, Gandon, Sine Moussa Abdou, Botla, Dara Andal, Nguebeul and Sakhor) located alongside the North-western coast of Senegal. These data cover the period of one year for each site. The annual wind speed distribution curves in all sites were obtained by using the Weibull distribution function. The results obtained show that the power density available is greaterduring the dry season than in the rainy season. In all sites, it appeared more important for the day-time than the night-time. For instance, the power density was 145.30 and 58.34 W/m² at the height of 20 m in the day and night, respectively in the site of Potou; it reveals 99.64 and 52.35 W/m² in the site of Kayar and 103.14 and 45.87 W/m² in Gandon during the same period and the same height. The corresponding average wind speeds are of 5.69 and 4.15 m/s in Potou, 5.04 and 3.80 m/s in Kayar and 5.13 and 3.77 m/s in Gandon. Key words: Weibull distribution, wind potential, diurnal characteristics, seasonal characteristics.