• Energy Research

AbstractReflection of the incident photons by the silicon surface is a major source of losses during photovoltaic conversion. However, these losses can be minimized by depositing an antireflection layer, usually silicon nitride SiNx: H, combined with an appropriate texturing. This layer should also provide a good passivation where a real dilemma can be arising. In contrast the surface passivation gets better with increasing Si content (large optical index for n > 2.3) and the minimum reflectivity was found for small optical index. To achieve this, one first approach consists to use a double antireflective layer with two materials of different refractive index n. Among the materials that are appropriate from the standpoint of physics and technology are SiNx:H-rich silicon, Oxynitride SiOxNy and silicon oxide SiOx. To optimize the antireflection multilayer, we have developed a numerical simulation code with Matlab software package where we have used the method of transfer matrix to solve the optical equation. These solutions permit us to plot the optical reflectivity and the absorption versus wavelengths and layer thicknesses. The optical refractive index and thicknesses of considered materials, which allowed us to have the lowest reflection, were used to simulate the electrical properties of the cell with PC1D and Silvaco software. Thus, our results showed the cell efficiency increase by 0.3% and effective reflectivity of 7.4% is obtained with a first oxide layer (n1=1.5 and d1=55nm), and a second layer of silicon nitride (n2=2.1 and d2=53nm) non-encapsulated compared to a reference solar cell (with a SARC SiN). In the case of multilayer non-encapsulated, our optimization has shown that it is possible to increase the efficiency by 0.7% with the refractive index (1.48, 2 and 2.4) and thicknesses (80, 5 and 50) nm.

AbstractThe necessity to find new forms of renewable energy is very important and urgent nowadays. The renewable sources of energy derived from the sun are one of the promising options. The photovoltaic cells as one of renewable energy sources have been largely studied in order to obtain cheap, efficient and secure PV cells. The conversion efficiency is the most important property in the PV domain. Indium gallium nitride (InGaN) alloys offer great potential for high-efficiency photovoltaics. We present numerical simulations of GaN/InGaN heterojunction solar cells by SCAPs simulation. The calculation of characteristic parameters: short-circuit current density, open-circuit voltage, and conversion efficiency. So, these simulations study the effect of indium content and thickness in these parameters. While the maximum efficiency of a p-n GaN/InGaN heterojunction solar cell with 0.2 indium composition is 2.78%, above an indium composition of 20%, the modeled heterojunction devices do not operate as solar cells.

Abstract The paper reviews the different detectable failures of mono-crystalline and poly-crystalline silicon in the research unit in renewable energies in Saharan medium (URERMS) fields. This survey is an effort to inspect and assess the defects of PV modules occurring in recent and older installations in a desert environment and under real operating conditions. The analysis and evaluation of 608 PV modules inside the site of URERMS and in a remote located solar installation (Melouka) using the visual inspection test results in the following failures and degradation modes: delamination, discoloration of the encapsulant, corrosion and discoloration of the metallization (gridlines, busbar, cell interconnect ribbon and string interconnect), solar cell cracks, broken glass, deterioration of the antireflection coating, snail trails, junction box failure, soiling. The electrical performance of some tested modules is also performed in order to give the correlation with the visual defects.

The PV module temperature is a crucial parameter in the performance of a grid-tied PV station and it has an important effect on the PV system efficiency. In this work, we are interested in predicti...

We use Silvaco software (atlas tcad) simulation to investigate the effect of dielectric layer deposed on rear surface of solar cells passivated emitter and rear totally diffused (PERT). For an improved performance for this solar cell, several physical factors must be considered, such as the light trapping behavior, and the resulting passivation performance and rear surface recombination currents were investigated. Particular consideration will be given to the back surface reflector (BSR) impact on reflection surface, interface passivation, and on the I–V characteristics. Numerical simulations show that using a layer of two dielectrics (SiNx/SiO2) with optical indices and thickness optimized in combination with contacts located (optimized metallization fraction f) at the rear surface allow for energy conversion efficiencies of 21.26% compared to a single layer of dielectric SiN 21.01%.

Abstract This paper presents a comparative study related to the impacts of the operating parameters. A structural design and modeling approach of the polymer electrolyte membrane (PEMFC) fuel cell is presented. The purpose of this study is to review many control and clarification strategies for fuel cell components that have been conducted by several researchers for improving the performance. The models that have been studied and compared to literature models appear clearly the dynamics of the PEM fuel cell. Consequently, the fuel cell performance is related to several parameters, which are ( δ , D H 2 , D O 2 , I 0 , I lim , r ). A simulation by MATLAB software is used to highlighting the powerful model compared to the mentioned models. The simulation results showed that many parameters change under different operating conditions such as, pressure, temperature and humidity. Finally, an accurate study shown that model 02 is the best model with an R2 value of 0.9994. This model has demonstrated a close agreement with the experimental data provided by a real fuel cell in the literature.

Abstract In order to support the growth of grid-tied photovoltaic power plant implementation in the Saharan environment. A detailed assessment analysis of 28 kWp photovoltaic (PV) system installed on the rooftop of Research Unit for Renewable Energies in Saharan region (URER/MS), located in southern Algeria (Adrar), has been carried out and presented in this paper. The monitoring data of the PV system over 12 months (March 2017 to February 2018), are used to evaluate both energy efficiency and the output power losses. The collected experimental data reveal that the environmental parameters variation has a direct effect on the performance of both the energy conversion efficiency and the system losses. From the monitoring data and the performance assessment, it was found that the highest final yield is 5.3 h/day while the irradiation and the ambient temperature are 518 W/m2 and 37.9 C° respectively. The annual production injected to the grid is 45.12 MWh, with 2.4 MWh energy losses are attributed to the grid voltage rise, 1.57 MWh energy is lost due to the array and thermal capture losses and system losses. The yield values of maximum/minimum monthly average reference and array yield values were; 6.7/5.4 h/day and 5.5/3.2 h/day respectively. The annual average PV module, inverter and system efficiencies reached; 11.37%, 96.46% and 10.99%, respectively. Some parameters of measured data; are used to calculate the harvested energy and performance ratio, and then compared with other PV systems installation located in different geographical regions worldwide. Finally, we have studied the impact of the grid voltage rise on the grid-connected photovoltaic system performance on both energetic and economical levels.

Abstract A detailed assessment analysis of 2.5 kWp photovoltaic (PV) system located in southern Algeria (Latitude 27.88 °N, Longitude −0.27 °E, Altitude 262 m) has been carried out in this paper in order to support the growth of grid-tied photovoltaic power plant implementation in the Saharan environment. The achievement of this analysis has been done by performing an accurate evaluation of the different impacts of the environment parameters on the operating performance of the grid-tied PV system. The data set covers 12 operating months and has been collected by our team from the Research Unit on Renewable Energy (URER-MS). The collected experimental data reveal that the environmental parameters variation has direct effect on the performance of both energy conversion efficiency and system losses. The grid was supplied with a power of 4322.65 kWh during the year 2015, where the annual average temperature was 28.30 °C. An important variation in performance parameters have been observed for different months. The yield values of max/min monthly average daily reference, array and final were; 7.68/5.7 kW h/kWp/day, 6.07/4.24 kW h/kWp/day and 5.75/3.98 kW h/kWp/day, respectively. The PV module, inverter and overall system efficiency reached; 14.19/11.10%, 95.34/93.94% and 13.53/10.50%, respectively. The experimental results indicate that the performance ratio (PR) varies from 66.66% to 85.93% and the annual average capacity factor was 7.91%.