by Djimba Niane, Alain K. Ehemba, Salif Cissé, Ousmane Diagne and Moustapha Dieng
Original Research
In this work, we studied the influence of the doping rate of the CIGSe layer on the recombination-generation mechanisms with 25 nm incorporation of a KF layer on a CIGSe solar cell. The different doping taken are Nb=1015cm-3, Nb=1016cm-3 et Nb=1017cm-3. Numerical modeling with the SCAPS-1D software shows that the generation rate varies slightly while that of recombination is very important, explained by a strong presence of traps in the CIGSe bandgap.
American Journal of Energy Research. 2018, 6(1), 30-34. DOI: 10.12691/ajer-6-1-5
Pub. Date: July 19, 2018
12244 Views2673 Downloads
by Ousmane Diagne, Djimba Niane, Alain Kassine Ehemba, Mouhamadou Mamour Soce and Moustapha Dieng
Original Research
We carried out, through the SCAPS-1D simulator, the survey of the curves of spectral response and J/V characteristic for different parabolic bandgap profile CIGS solar cells. The variable parameter for these different samples is the gallium rate of the CIGS absorber layer. The theoretical model coincides with the one-dimensional model of a heterojunction consisting of a window layer (ZnS), a buffer layer (CdS) and an absorbing layer (Cu(In,Ga)Se₂). The analysis of the results obtained allowed us to identify and evaluate the adjustments that would have to be made, compared to the gallium composition, in order to have an optimal efficiency. Thus, after various adjustments, we obtain a powerful cell that displays a conversion efficiency of around 23.68%. This cell is characterized by a bowing factor (b) equal to 10% and Ga local composition rates equal to 25% and 35% respectively at the junction and the back contact.
American Journal of Energy Research. 2018, 6(1), 23-29. DOI: 10.12691/ajer-6-1-4
Pub. Date: July 19, 2018
17157 Views2337 Downloads
by Abdul Gafur Nazordine Mahomed Bay
Review Article
This study explores the relationship between energy consumption and economic growth in Mozambique for 1975-2016 period, using Vector error correction model and Granger causality test. The VECM result suggests the existence of unidirectional long-run relationship running from EC to GDP. Granger causality test proposes that energy consumption Granger causes economic growth. Therefore, in Mozambique is indispensable an energy consumption development policy to stimulate economic growth. Mozambique has plentiful energy resources that would boost the development of energy sector and supply the emergent industry without any energy shortage.
American Journal of Energy Research. 2018, 6(1), 19-22. DOI: 10.12691/ajer-6-1-3
Pub. Date: July 10, 2018
10369 Views2677 Downloads1 Likes
by Hoe-Gil Lee, Jash N Shah, Panshul Tyagi and Vigneshwar M
Original Research
Solar energy is an important aspect of renewable energy because we can easily obtain access to the source. The photovoltaic (PV) cell is the fundamental unit in the power conversion of the solar system. When the PV cells are exposed to partial shading as a result of a multitude of environmental conditions, the performance of the solar PV module is remarkably affected in terms of the efficiency of the system. In many cases, the PV arrays are shadowed, whether completely or partially, by passing clouds, neighboring buildings and towers, trees, or the shadow of one solar array falling on another. This study investigates the effects of partial shading on energy output of different configurations of solar PV modules. In this study, three different solar PV configurations are investigated: 1) Series 2) Parallel, and 3) Series-Parallel. All the considered PV configurations are analyzed using several possible scenarios of shading in order to evaluate their performances and to find a configuration that is comparatively less susceptible to electrical mismatches due to shadow problems. Owing to the practical difficulty of conducting experiments on varied array sizes, the proposed model also includes a general model of a PV module, which was implemented on MATLAB/Simulink and has been developed for any required array size, configuration and different shading patterns. This model is simple and especially useful to calculate the actual performances of the PV modules under various operating conditions.
American Journal of Energy Research. 2018, 6(1), 8-18. DOI: 10.12691/ajer-6-1-2
Pub. Date: July 06, 2018
24565 Views2996 Downloads
by DJIAKO Thomas, TAWETSING M. P. Olivier, EDOUN Marcel, DESMORIEUX Helène and KUITCHE Alexis
Original Research
The present work is part of the optimization of indirect solar dryers. The main objective is to highlight the influence of topological forms of dryers on air settings. For this, we have studied the behavior of air in the collector for four inclinations angles (0°, 30°, 40° and 60°), three values of the height of the drying chamber (1, 1.20 and 1.40 m) and three values of the height of the chimney (0.3, 0.8, and 1.5 m). The Navier-Stokes equations were numerically solved using the finite volume method through the Easy CFD_G package code in its V.4.1.0 version. The numerical simulation was used to define for each load configuration studied, the temperature profile, velocity and pressure. The results show that for the solar collector, 30° is the optimum angle of inclination. This angle provides a better distribution of the velocity vector field. For this angle, the height of the drying chamber allowing a better distribution of velocity and temperature gradient is 1.40 m. The maximum chimney height is 1.5 m. These parameters are used to define an optimal configuration of the indirect solar dryer in which the air temperature varies between 56 and 64°C and drying air velocity between 0.5 and 0.9 m/s.
American Journal of Energy Research. 2018, 6(1), 1-7. DOI: 10.12691/ajer-6-1-1
Pub. Date: June 30, 2018
15564 Views2067 Downloads