Vincent Sambou

Impacts of aerosols on available solar energy at Mbour, Senegal

This study aims to evaluate the available solar potential (direct normal on the overall horizontal plane) and to estimate the observed impact of aerosols on solar radiation at Mbour, Senegal (16.958 °W; 14. 394 °N) using observations from solar instruments and AERONET during 2006. The results show the presence of a good available solar potential. At intra-seasonal timescale, the total and direct normal energy are stronger in May with a mean value of 7 kWh/m2/day and February with an average value of 5.50 kWh/m2/day. The lower available total and direct normal solar energies are, respectively, found in August (5.31 kWh/m2/day) and July (2.90 kWh/m2/day). The observations of AERONET show that aerosol optical depth values are higher in June (0.7) and lower in February (0.16). These results are consistent with the observed trends of total and direct normal energy during those months. Case studies of the influence of aerosols on available solar energy show a mean decrease of 10% and 28%, respectively, for the ...

Modeling of the thermal performance of air-filled partitioned enclosures: Effects of the geometry and thermal properties:

Enclosures divided by multiple vertical diffusive partitions have a high insulating quality and may provide tangible benefits as a construction material. The enclosure under investigation is differentially heated, with adiabatic bottom and top sides. The three coupled modes of heat transfer are investigated numerically. An analysis of the interaction of natural convection and surface radiation has been conducted by studying the influence of the partitions and walls surface emissivity. A parametric study is conducted to point out the influence on global heat transfer of some parameters such as partitions number, enclosure void fraction, and thermal conductivity ratio of partitions and side walls.

Investigation of Degradation in Crystalline Silicon Photovoltaic Modules After 10 Years Exposition in Senegal by Infrared (IR) and Electroluminescence (EL)

The effects of a sub-Saharan coastal climate on PV modules degradation was studied in this paper. A Mono and a polycrystalline-silicone solar PV module exposed in Dakar, dry and coastal climate, at the extreme West of Senegal was studied. As first inspection in this region, the electrical parameters of two PV modules A and B operated during about 10 years, are measured under standard testing condition (STC) and their I-V characteristics were fitted. The initial I-V characteristics was performed under real conditions and translated to STC and compared to the measured I-V characteristics at standard test conditions (STC) obtained in PV Laboratory after exposition. After the operating years, the main important parameters of the studied PV modules: short-circuit current ISC, open circuit voltage UOC, maximum power PMPP, nominal current IMPP and Voltage VMPP are evaluated and then compared to the initial parameters obtained during initial exposition to estimate their degradation.

Study of the Correlation Between the Dust Density Accumulated on Photovoltaic Module’s Surface and Their Performance Characteristics Degradation

One of the major constraints related to the operating conditions of photovoltaic systems in the Sahelian environment is relative to the deposits of dust on the surface of the PV modules. Indeed, the Sahel is characterized by frequent and permanent sandstorm that impact on its strong solar potential. However, opinions are still divided on the significant impact of dust on photovoltaic modules production. This paper deals with the correlation between the density of deposited dust on the surface of crystalline silicon photovoltaic modules and the impact on their performances. This study is carried out on two different modules a monocrystalline and a polycrystalline technology. It focuses on the open-circuit voltage (VOC), the short-circuit current (Isc), the fill factor (FF) and more particularly on the maximum power (Pmax). This paper presents the methodology and the experimental study used to measure the environmental parameters (irradiation, temperature, and humidity), the density of deposited dust and the performance characteristics (ISC, VOC, FF and Pmax). Finally, the results of the correlation between the density of deposited dust and the performance characteristics of PV modules are presented.