Polycrystalline Photovoltaic Cells Research Articles

High-efficiency polycrystalline solar cells via COC-SiO2 anti-reflective coversheets: A study on power conversion and thermal impact

Solar photovoltaics (PV) is an essential part of renewable energy for the sustainable future. The worldwide installed capacity of solar panels recently exceeded 1TWp. The solar cells encounter around 30 % reflection losses at the surface of the front glass. This research focuses on the development of cyclic olefin copolymer (COC) coversheets for polycrystalline photovoltaic cells to minimize the reflection loss. Additionally, silicon dioxide (SiO2) was added at 1 wt%, 2 wt%, 3 wt% and 4 wt% with COC to produce COCS coversheets by Fused Deposition Modelling (FDM) technique. An investigation was conducted on the crystal structure, morphology and efficiency of anti-reflective coversheets on both open and closed (neodymium light) environments. Neodymium light has a natural filter to diffuse the dull yellow/green portions of the spectrum that produces light radiation much similar to natural sunlight. The COCS3 covered photovoltaic cells exhibited a lowest reflection of 6.91 % and highest absorbance of 90.2 % in the UV–visible wavelength (300–800 nm). The COCS3 coversheet achieves a highest power conversion efficiency (PCE) of 18.06 % under open-source environments and 19.71 % under regulated environments. As observed, the COCS3 sample results in lower electrical resistivity of 3.45 × 10−3 Ω cm, carrier concentration (37.10 × 1020 cm−3) and higher hall mobility (14.30 cm2/Vs). The COCS3 covered photovoltaic cells exhibits the lowest surface temperature, reaching 31.5 °C under open-source and 45.8 °C under regulated source conditions. The findings clearly demonstrates that COCS coversheets have the ability to effectively reduce reflection loss in polycrystalline Si photovoltaic cells.

Polycrystalline silicon photovoltaic cell defects detection based on global context information and multi-scale feature fusion in electroluminescence images

In photovoltaic (PV) cell inspection, electroluminescence (EL) imaging provides high spatial resolution for detecting various types of defects. The recent integration of EL imaging with deep learning models has enhanced the recognition of defects in PV cells. However, the high surface impurity content in polycrystalline silicon PV cells presents a challenge. Defect features can be similar to complex background textures, making highlighting features for small target defects difficult and leading to potential misclassification as background or other classes. To address these challenges, we propose a novel deep convolutional neural network (CNN) model for effectively identifying small target defects in polycrystalline PV cells. We first utilize a global context information (GCI) block to improve CNN’s modeling of global information, aiding in distinguishing PV cell defects with similar local details. Moreover, we design a channel weight feature pyramid (CWFP) that dynamically adjusts the channel weights of extracted features. We further achieve multi-scale feature fusion through the pyramid structure to enhance the resolution capability for small targets. The proposed model was evaluated on a publicly available dataset of 8 defect classes in polycrystalline PV cells, achieving an accuracy of 96.36 %. The experimental results show that the proposed model outperforms existing deep learning models in detecting small target defects with higher precision.

MATHEMATICAL MODELLING AND OPTIMIZATION OF POLY-CRYSTALLINE PHOTOVOLTAIC MODULE

This work proposes modeling and optimization of poly-crystalline photovoltaic (PV) modules, validated with experiment, using single diode (SDM) and double diode model(DDM). The PV cell is treated as an equivalent electrical circuit with series and shunt resistance. The weather data like temperature and irradiance are used as input variables. The operating current and maximum power point are obtained using three variables: current, voltage, and power. An experiment was set up in Nagpur city, on the Deccan plateau situated in central India. This place is suited for PV installation due to the high average solar insolation period throughout the year. The outputs of the PV model are optimized using a genetic algorithm (GA) and simulated annealing (SA) algorithm and validated against the experiments with variable load conditions. The metaheuristics optimization techniques worked well for this model and improved the accuracy and precision of the current-voltage (I-V) and power voltage (P-V) curves. The present work compares the errors of the SA and GA algorithms used for extracting the five key points of (I -V) curves using the normalized sum of squared errors (NSSE). The proposed model optimization results are in close agreement with experimental results.

Preliminary Studies on Design of Photovoltaic Thermal (PVT) Solar Collector for Roofing System Application.

This study was conducted to develop and study the performance of a Photovoltaic Thermal (PVT) system technology, a system which combines the Photovoltaic (PV) system with a solar thermal (T) system that produces electricity and hot water simultaneously. The objective of this study is to develop a working prototype of the PVT system for roofing system application with water as the cooling agent. A polycrystalline PV cells was used as the solar collector while a transparent rubber tube was attached at the backside of the PV panel with water flowing directly from a water tap source. Two designs were examined for the heat absorber design which was categorized as the parallel and spiral flow design. The system was run at an open space to simulate real life application. A working PVT system was developed; however an electrical efficiency drops 0.3% and 1.07% on the parallel and spiral design respectively when compared to the standard PV system.

Preliminary SWCNTs-kerosene on Carreau MHD flow over a wall with distinct thickness

The Magnetohydrodynamics (MHD) Carreau over a stretched surface on a kerosene oil based is examined in this paper. Most specifically, we extended and reported the effects of various parameter namely; magnetic field, thermal radiative and heat generation on the temperature. Thermal conductivity enhancements of water and seawater in the presence of single-walled carbon nanotubes (SWCNTs) are presented. We used transformation of similarity to reduce and regenerated the partial differential equations (PDEs) into ordinary differential equations (ODEs) for the nonlinear governing equation alongside with their related boundary conditions. The result of the regenerated ODEs is solved numerically by the application of the fourth/fifth order Runge Kutta Fehlberg technique with method of shooting using Maple code. The result obtained indicated that there is significant positive correlation between high electric field. The result reported that the temperature parameter is decreased with all parameter when the electric is high (El=0.5), which indicated that the electric filed is a dominant of SWCNTs-kerosene.his study was conducted to develop and study the performance of a Photovoltaic Thermal (PVT) system technology, a system which combines the Photovoltaic (PV) system with a solar thermal (T) system that produces electricity and hot water simultaneously. The objective of this study is to develop a working prototype of the PVT system for roofing system application with water as the cooling agent. A polycrystalline PV cells was used as the solar collector while a transparent rubber tube was attached at the backside of the PV panel with water flowing directly from a water tap source. Two designs were examined for the heat absorber design which was categorized as the parallel and spiral flow design. The system was run at an open space to simulate real life application. A working PVT system was developed; however an electrical efficiency drops 0.3% and 1.07% on the parallel and spiral design respectively when compared to the standard PV system.

A Review on Improved Performance for Solar Photovoltaic Cells by Various Cooling Methods

The performance of a photovoltaic cell (PV) not only depends on the irradiance of the light but also depends on the surrounding temperature where it is installed. Solar is one of the innovative devices among photovoltaic cells. It is noticed that by increasing operating temperature, the efficiency of a photovoltaic solar cell decreases nearly 0.5% / oC. Due to the rise in ambient temperature, it declines open circuit voltage, fill factor, generated power, overall efficiency etc. sharply. It creates an unbounded damage both for monocrystalline and polycrystalline photovoltaic cells applied for power usage. To restrain these limitations and get the functionate temperature specified by the industrialist proper cooling methods should be used mandatorily. Till now, it has not mentioned a detailed analysis on various cooling methods for photovoltaic solar cells to get a good outcome. This review paper represents an indication of several active and passive cooling ways such as air cooling , water cooling, heat pipe cooling, cooling by phase change materials, cooling by nanofluid fins, geographical position etc. briefly to improve the PV cell performance economically.

Performance Analysis of Submerged Polycrystalline Photovoltaic Cell in Varying Water Conditions

Exploring the underwater solar energy by solar photovoltaic (PV) cells leads to a huge advantage by utilizing the humongous space of water covered by the earth's surface. Even though the amount of solar radiation decreases with the depth of the water, water provides sustainable cooling and cleaning for solar PV cells underwater. There are many challenges and constraints to develop solar PV cells underwater because they are mostly calibrated and amenable to space, dryland, terrestrial, etc., and the solar spectrum is prone to get narrower with the depth of the water. The implementation of solar PV cells underwater is pliable in various commercial and defense applications, such as sensors, water monitoring systems, autonomous vehicles, underwater gliders, etc. In this article, first, a mathematical model has been developed for the solar cell spectrum to incorporate the changes in the solar irradiance with the depth of the water. Furthermore, an experimental setup was designed and implemented to mimic an underwater environment. The performance of the polycrystalline encapsulated solar cell was studied based on the different types of water and the depth of the solar cell underwater. This article manifests that there is a sufficient amount of underwater solar power that can be utilized using PV cells to operate various devices and systems.

Characterization of a polycrystalline photovoltaic cell using artificial neural networks

This article presents a method to estimate the parameters of a photovoltaic cell model in its equivalent circuit of a single-diode using artificial neural networks; more specifically, the multilayer perceptron concept is used. The data required to estimate the parameters are based solely on the information available in the manufacturer’s data sheet. The neural network has two hidden layers and the selected training method was Bayesian regularization. The training data were produced synthetically to ensure that a large part of the range of possible parameter values is covered. The network performance is validated with a data set not included in the training set, making the comparison with a recognised method from the literature, and even more, with experimental data obtained from a real photovoltaic panel. The main advantage of this method is that, once the network is trained, the parameters returned by the network will always be unique for each input provided, which is not the case with other artificial intelligence methods such as genetic algorithms or differential evolution. In addition, this method can be directly applied to other similar problems, only by modifying the inputs and outputs of the network.

Degradation and fault diagnosis of photovoltaic cells using impedance spectroscopy

Impedance spectroscopy is widely employed to evaluate electrochemical devices, and our group has been proposing its use as a novel diagnosis tool for photovoltaic modules. In this study, photovoltaic cells are subjected to several types of failure and degradation that frequently occur in polycrystalline photovoltaic cells, such as mechanical stress, interconnect ribbon disconnection, and potential-induced degradation. The impedance characteristics of these cells are measured as Nyquist plots, in addition to the current-voltage (I-V) characteristics to compare the characteristics among the failure modes and demonstrate the applicability of impedance spectroscopy as a potential photovoltaic module diagnosis tool. The equivalent circuit parameters, with and without failure and degradation, are obtained from the impedance characteristics and compared. The influence of bias voltage and temperature on the impedance characteristics are investigated prior to failure and degradation. The application of mechanical stress decreases the parallel resistance and moves the right edge of the Nyquist plot further inside the exact semicircle, while interconnection ribbon disconnection also decreases the parallel resistance and increases the series resistance, and potential-induced degradation decreases both the parallel resistance and capacitance.

Efficiency Improvement of a Photovoltaic Module Using Front Surface Cooling Method in Summer and Winter Conditions

Photovoltaic (PV) cells exhibit long-term degradation, when its temperature exceeds a certain limit. On the other hand, decreasing the temperature results in lower PV cell efficiency. The aim of this paper is to demonstrate the improvements in the output power and efficiency of PV modules using a cooling system based on flowing water on the front surface. Front surface cooling method with the help of a water pumping system is one of the most promising methods for cooling the PV cells. With poly-crystalline PV cells, different water flow rates are experimented, and the output power and the efficiency are computed for different weather conditions. These experiments yield that the cell efficiency is improved by approximately 27.3% in winter conditions and 27.6% in summer conditions.

Optimization of AZO films for integrating optically transparent antennas with photovoltaics

The importance of having an optimal material for fabricating Optically Transparent Antennas (OTAs) is crucial for designing highly efficient antennas that can be integrated with photovoltaics. Transparent Conductor Oxides are promising for OTA fabrication due to their capability of being simultaneously transparent at optical frequencies and conductive within the radio frequency (RF) range. Here in this study, thin aluminum and zinc oxide layers were co-sputtered onto Si and a polycrystalline photovoltaic cell and then annealed between 350 °C and 450 °C for 24 and 48 h in a N2 ambient. The annealing process ensured the formation of Aluminum Zinc Oxide (AZO) with low resistivity ≈10−5 Ω cm and a transparency of 86% between 350 and 750 nm. The material was tested by performing RF characterization and by fabricating and testing two different OTAs. The results of the optimization process and characterization show that the AZO material is feasible for OTA fabrication.

Experimental Analysis of Effect of Vegetation under PV Solar Panel on Performance of Polycrystalline Solar Panel

The polycrystalline photovoltaic cell has an efficiency around 11-14%. The efficiency is low because of different factor, out of which the temperature is one of affecting factor on efficiency. The solar cell efficiency decreases with increase in temperature. So it is necessary to cool the PV panel to improve its efficiency. Cooling of PV panel is one of critical issue during the planning of installation of PV plant. In the present work cooling of photovoltaic panel via different vegetation and water tray is carried out. The aim of this project is to optimize the panel efficiency by controlling the panel surface temperature by cultivating different vegetation below the panel. The experiment is done for polycrystalline silicon cell. The plants selected for the experimentation has a good evapotranspiration effect except aloe vera. The numerical value of increase in instantaneous efficiency is 3-4%, 1.8-2.2%, 1.2 -2%, 0.2 -0.5% for water tray, peppermint, tulsi and aloe vera respectively. The economical benefits due to cultivation of peppermint, tulsi aloe vera and water tray and also due to increase in power production from 1MW solar plant per year is forecasted has Rs. /- 455250, 436012, 219150 and 778850 respectively.

Study on the possibility of use of photovoltaic cells for the supply of electrolysers

Study on the possibility of use of photovoltaic cells for the supply of electrolysers Photovoltaic cells have been used for a long time to supply the electrical devices of small power in areas without access to the electricity networks (or other sources of electric energy). The ecological aspect of the use of the renewable energy sources, together with the technology development and increasingly lower costs of production the photovoltaic cells, cause the increase of their application. The solar power plants are built in several places in the world, not necessarily in the areas of high light intensity. Nowadays, such developments mostly depend on the wealth of a particular country. The largest photovoltaic power stations have power of a several dozen of MW. The major disadvantage of the photovoltaic cells is that the energy production is possible only during the day. This causes a necessity of energy accumulation in large photovoltaic systems. One possibility of storing large amounts of energy gives a hydrogen fuel, generated in the electrolysers powered directly from photovoltaic cells. Hydrogen, stored in pressure tanks or in tanks with synthetic porous materials, can be again used to produce electricity in fuel cells. This paper introduces selected issues and test results associated with the use of photovoltaic cells to power the hydrogen generators. The possible connections of photovoltaic modules integrated with electrolysers were analyzed. In this article the results of the electricity daily production by polycrystalline photovoltaic cells, collected in the course of the entire year were also presented.

Crack detection in photovoltaic cells by interferometric analysis of electronic speckle patterns

Cracking is a common problem encountered during the fabrication of crystalline silicon photovoltaic (PV) cells. In this study, electronic speckle pattern interferometry (ESPI) is developed as a tool for rapid identification of cracks in PV cells. Thermally induced cell deformation of defect-free and defect-bearing PV cells was first modeled with numerical simulations and then experimentally studied by optical configuration for ESPI measurement of out-of-plane deformations. Both numerical and experimental results indicate that the speckle patterns imparted during thermal deformation of a cell allow for simultaneous quantification of crack size, location and type in both single- and poly-crystalline PV cells. Speckle patterns near defects were manifested as continuous, chevron-shaped, and broken fringes for scratch, surface cracks, and through cracks, respectively. For comparison to other existing techniques, full field electroluminescent images were also provided for every defective PV cell. Electroluminescent imaging is capable of detecting cracks, but unlike ESPI, is unable to distinguish between the different types of cracks. Because the amount of heating needed to induce out-of-plane deformation resolvable by ESPI is small (<0.5°C) and because ESPI is sensitive to crack type, the ESPI-based imaging study presented here can potentially be developed into a rapid, non-destructive inspection tool for the structural integrity of solar cells at any point within the manufacturing process.

Advances in crystalline silicon solar cell technology for industrial mass production

Crystalline silicon photovoltaic (PV) cells are used in the largest quantity of all types of solar cells on the market, representing about 90% of the world total PV cell production in 2008. Crystalline silicon solar cells are also expected to have a primary role in the future PV market. This article reviews the current technologies used for the production and application of crystalline silicon PV cells. The highest energy conversion efficiency reported so far for research crystalline silicon PV cells is 25%. Standard industrial cells, however, remain limited to 15–18% with the exception of certain high-efficiency cells capable of efficiencies greater than 20%. High-efficiency research PV cells have advantages in performance but are often unsuitable for low-cost production due to their complex structures and the lengthy manufacturing processes required for fabrication. Various technologies for mono- and polycrystalline PV cells are compared and discussed with respect to the corresponding material technologies, such as silicon ingot and wafer production. High energy conversion efficiency and low processing cost can only be achieved simultaneously through the development of advanced production technologies and equipment, and some of the latest technologies that could lead to efficiencies of greater than 25% and commercially viable production costs are reviewed.

The effects of the growth parameters of the CdS window layer on the photovoltaic properties of MOCVD-grown CdS/CdTe solar cells

This paper forms part of an ongoing study aimed at producing high-efficiency polycrystalline photovoltaic cells by a single integrated process using metal organic chemical vapor deposition (MOCVD). Relationships between CdS growth variables, final microstructure and device performance parameters are established. CdTe grain sizes of 3–5 μm diameter can be achieved using CdS growth temperatures of 275 °C or below, even in the absence of nucleation delay. Short-circuit photocurrent depends on CdS growth temperature and dopant concentration.

Study on Sulfur Passivation for CuInSe2 Polycrystalline Thin Film With (NH4)2SX Solution

ABSTRACTIn this work, we studied the removal of the native oxide on polycrystalline CuInSe2 thin films by KCN and effect of subsequent chemical sulfurization with (NH4)2Sx solution on these films. As a result of the treatment, a portion of the selenide film was transformed into Culn(S,Se)2 The Auger Electron Spectroscopy and X-ray photoelectron spectroscopy studies showed that KCN removed the oxygen and the sulfurization prevented regrowth of the oxides. The optical bandgap of the sulfurized films increased about 0.27 eV. From these experiments, we concluded that sulfur atoms are incorporated in the CuInSe2 to form a stable and higher bandgap layer, Culn(S,Se)2 which may passivate the CuInSe2 and improve the performance of polycrystalline photovoltaic cells made from it.

Photovoltaic-cell technologies joust for position: The fabrication of solar cells has become a bona fide industry with three versions vying to dominate the marketplace

An examination is made of current technologies as well as single-crystal silicon which is found to be the most efficient commercially. A discussion is also presented of polycrystalline photovoltaic cells and amorphous silicon.