Thin-film Photovoltaic Modules Research Articles

Compound control strategy for maximum power point tracking with flexible step-up converters for thin film photovoltaic module applications

Compound control strategy for maximum power point tracking with flexible step-up converters for thin film photovoltaic module applications

Influence of Light Irradiation on Potential-Induced Degradation for Thin-Film Si Photovoltaic Modules

Delamination observed for superstrate-type thin-film Si photovoltaic (PV) modules exposed outdoors was reproduced by indoor acceleration test with high-voltage application. Such delamination was observed for the PV modules left in the air after potential-induced degradation (PID) acceleration test and was a kind of PID. The delamination occurred near the interface between glass and transparent conductive oxide. In this study the origins of the delamination for thin-film Si PV modules were analyzed and the influences of light irradiation and humidity were also investigated. The delamination occurred only at the position with voltage application and high concentration of Na was detected at the delamination region. Delamination was also enhanced by high humidity. It also turned out that light irradiation delays both deterioration of PV performances and also the delamination by high-voltage application. However, PID behaviors are almost the same regardless of including UV component. This is much different from crystalline Si case that UV component is required for the PID delay.

Marine predators algorithm for parameters estimation of photovoltaic modules considering various weather conditions

The accurate models of photovoltaic systems are the core of solar energy studies that are describing the system performance and behavior under different operating conditions. The improving of photovoltaic models based on optimizing method is recently the main simulation tool to construct I-V and P–V characteristic curves with the aid of system parameters. These parameters are extracted by using powerful optimal techniques that are building-up from datasheet of manufacturers or experimental data. This paper presents a novel proposed photovoltaic model based on Marine Predators Algorithm to estimate the optimal model parameters of solar cells or modules. Also, it can extract parameters of single diode, double diode and three diode models. Moreover, the Route Mean Square Error value between each model computed parameters and measured results of photovoltaic components are considered as the objective function. R.T.C. France Solar Cell, Photowatt-PWP201 and thin-film photovoltaic modules have been implemented to extract parameters for all three previously mentioned models at different irradiance intensities or temperature degrees. The proposed algorithm results of such cells and modules for each diode model are compared with other research works and manufacturer's results. Moreover, the evaluation of proposed algorithm has been presented considering the complexity analysis and statistical tests. The compared results show that, the accuracy of algorithm results is the best and their I-V and P–V characteristic curves are highly coinciding with manufacturer's curves. Therefore, the results of the proposed algorithm are satisfied with high superiority and better reliability to optimize parameters under different operating conditions.

Hot-spot generation model using electrical and thermal equivalent circuits for a copper indium gallium selenide photovoltaic module

Hot-spot generation is critical to the reliability and performance of copper indium gallium selenide (CIGS) solar cells; however, its occurrence mechanism has not been fully elucidated. We conducted a partial shade stress test on three large-area CIGS modules (156 cm × 62.6 cm in size, with 102 cells) connected in series. Partial shade stress can cause irreversible and unpredictable damage to the modules, and we confirmed the generation of hot spots on the shaded cells via infrared imaging. To emulate numerically the internal electrical and thermal changes in the shaded cells, we present electrical and thermal equivalent circuits based on the material properties and layered structure of the CIGS cells and modules. Furthermore, we propose a hot-spot generation model describing the irreversible damage to CIGS cells via shunt resistance degradation because the dissipated electrical power exceeds the threshold power (Pth). The current–voltage characteristics simulated by the presented method are congruent with those measured under partial shade conditions. Partial shade induces high electrical power consumption in the shaded cells, up to ~34 mW/cm2 at a 5% shade ratio, ~1,500 times higher than that in the unshaded cells. The shunt resistance is degraded to ~18.5 Ω/mm2 (only ~0.1% of the initial normal value), and the Pth-value is estimated to be ~2.4 mW/cm2 at the center of the hot-spot cells. The presented method and Pth-parameter can be used to evaluate durability with respect to the effects of partial shade stress for CIGS and various other thin-film photovoltaic cells and modules.

Performance Evaluation of Various Photovoltaic Module Technologies at Nawabshah Pakistan

The purpose of this study was to evaluate the influence of module temperature on the efficiency of polycrystalline (p-Si), monocrystalline (m-Si), amorphous (a-Si) and thin film photovoltaic modules at outdoor environment of Nawabshah city Pakistan. The experimental setup was made and installed over the top roof of departmental building. Weather conditions, such as global solar radiation, ambient temperature, wind speed and relative humidity, power output and temperature of all selected four types of module technologies were measured at the site by logging data. Then, the logged data was normalized because of different rated power of photovoltaic modules for comparison purpose. Results revealed that less temperature impact was noted from thin film module and thus it gave more normalized power with 45.6% among other examined modules. On the basis of overall efficiency, p-Si, m-Si, a-Si and thin film modules gave 92.4%, 93.7%, 94.4% and 95.4% yearly average normalized efficiencies respectively. It was found that temperature has more impact on the efficiency of other examined modules compared to thin film modules. Thus, it is concluded from the study that thin film module is better in outdoor environment of Nawabshah

Investigational evaluation of a thin film photovoltaic module by incorporating phase change material: An experimental approach

The operating performance of the solar photovoltaic (SPV) modules is perturbed by the temperature, wind, soiling and relative humidity. Among these parameters, temperature puts the most negative impact on the output yield of the module. On increasing the temperature of the SPV module, the output power decreases drastically. The decrease in temperature affects the power output of the photovoltaic module and the average power yield drops down very sharply. In the present study, the experimental analysis of two 45-watt thin films photovoltaic module with similar characteristics has been carried out. One of the modules is used as the reference module and the second module is incorporate with phase change material at the backside to decrease the cell temperature. It was observed that the photovoltaic thermal module with phase change material (PV/T-PCM) combined system was producing a higher output power as compared to the reference SPV module. An increment of 1.55% in the electrical efficiency of SPV module was recorded during the study period. The thermal efficiency of the PV/T-PCM system was analysed at the constant flow rate of the water. A rise of 20 °C in outlet water temperature was recorded from the PV/T system. The hot water obtained was collected in the reservoir which can be used for low heat applications.

Photovoltaic Modules Selection from Shading Effects on Different Materials

This study aims to provide photovoltaic module selection with better performance in the shading condition for improving production efficiency and reducing photovoltaic system investment cost through the symmetry concept, combining both solar energy mathematical and engineering principles. The study builds a symmetrical photovoltaic model and uses the series-parallel circuit theory, piecewise function and Matlab simulation. The voltage and current output characteristics of commercial photovoltaic modules made of different materials and structures are analyzed and their shading effects are evaluated. The results show that for each photovoltaic module, the output power is directly proportional to the irradiance. The output voltage of the photovoltaic module slightly increases and the output current greatly decreases from no shading to shading. The rate of output power reduction varies for each photovoltaic module type when the irradiance changes. The thin film modules show a lower output power reduction rate than crystalline photovoltaic modules from no shading to shading and they have good adaptability to shading. The use of thin film photovoltaic modules is recommended when the shading condition cannot be avoided.

Low Sun Spectrum on Simulation of a Thin Film Photovoltaic, Heat Absorber, and Thermoelectric Generator System

The research presents the simulation results with Matlab on combining of a type of thin-film photovoltaic module (a-Si), a copper plate heat absorber with thermoelectric generators (TEG) utilizing the standard low-sun spectrum AM1.5G at 0.05, 0.06, 0.07, 0.08, 0.09 and 0.1 Sun as a source of radiation. Amorphous silicon is a type of thin-film solar cell that is more suitable for indoor use so that by using a source of low-intensity light radiation from the sun will still generate electrical energy conversion. Spectrum splitting is used as a cold mirror, which reflects the spectrum of light to the a-Si module in the form of photon energy while transmitting to the TEG module the spectrum of near-infrared light radiation in the form of heat. On the hot side of the TEG, a copper plate was placed to accommodate the heat from light radiation to increase convection heat transfer and temperature ifferences between the hot and cold sides of the TEG. The simulation results show that the highest efficiency of a-Si module is 3.46% achieved at the lowest spectrum of 0.05 Sun, vice versa TEG is at the highest spectrum at 0.1 Sun and 10.05% its efficiency. This low sun spectrum will be a milestone in the utilization of bulb radiation energy in general domestic needs.

Sustainable End of Life Management of Crystalline Silicon and Thin Film Solar Photovoltaic Waste: The Impact of Transportation

This work provides economic and environmental analyses of transportation-related impacts of different photovoltaic (PV) module technologies at their end-of-life (EoL) phase. Our results show that crystalline silicon (c-Si) modules are the most economical PV technology (United States Dollars (USD) 2.3 per 1 m2 PV module (or 0.87 ¢/W) for transporting in the United States for 1000 km). Furthermore, we found that the financial costs of truck transportation for PV modules for 2000 km are only slightly more than for 1000 km. CO2-eq emissions associated with transport are a significant share of the EoL impacts, and those for copper indium gallium selenide (CIGS) PV modules are always higher than for c-Si and CdTe PV. Transportation associated CO2-eq emissions contribute 47%, 28%, and 40% of overall EoL impacts of c-Si, CdTe, and CIGS PV wastes, respectively. Overall, gasoline-fueled trucks have 65–95% more environmental impacts compared to alternative transportation options of the diesel and electric trains and ships. Finally, a hotspot analysis on the entire life cycle CO2-eq emissions of different PV technologies showed that the EoL phase-related emissions are more significant for thin-film PV modules compared to crystalline silicon PV technologies and, so, more environmentally friendly material recovery methods should be developed for thin film PV.

Exergy analysis of thin-film solar PV module in ground-mount, floating and submerged installation methods

The scope for water-based photovoltaic (WPV) installations has raised questions related to its performance in comparison to traditional land-based photovoltaic (LPV) installations. In literature, few studies exist, and they mainly highlighted the performance of WPV and LPV based on energy analysis but fails to give a detailed understanding. In this paper, the exergy based parametric approach is used to understand the realistic performance and the energy conversion process of the photovoltaic (PV) module in both water and land environments. Three amorphous silicon thin-film PV modules installed in ground-mount PV (GMPV), floating PV (FPV), and submerged PV (SPV) methods are considered for experimentation to understand the exergy performance. The experimental results show that the exergy efficiency is varied for each installation method. It is observed that the exergy efficiency of SPV is 3.07% higher than the FPV and 43.65% higher than GMPV installation methods, respectively. Overall, the thermodynamic analysis of the thin-film PV module provided in this study delivered a critical understanding of the performance, and this study will serve as a useful reference in selecting the best installation methods.

Estudio de los métodos analíticos para la extracción de parámetros eléctricos de módulos fotovoltaicos de capas delgadas

Para conocer la eficiencia real de un panel y poder predecir su potencia y producción energética es necesario estudiar su comportamiento y caracterizarlo a las condiciones reales del lugar en el que está instalado. El modelo de un solo diodo para celdas fotovoltaicas (FV) relaciona la corriente y el voltaje del módulo FV mediante cinco parámetros eléctricos que nos dan información fundamental acerca de los procesos físicos que tienen lugar en las celdas FV y del estado del módulo. Actualmente, existen diversos métodos analíticos, numéricos y heurísticos para extraer los parámetros del modelo, cada uno con ventajas y desventajas que dependen del tipo de módulo y de las condiciones ambientales. Se realizó un estudio de métodos de extracción analíticos que se usan actualmente para módulos FV de silicio cristalino y se aplicaron a tecnologías FV de capas delgadas. En este trabajo se presentan los resultados de la extracción de parámetros a través de comparación entre la curva corriente-voltaje (IV) medida y la modelada, además de cálculos de Normalized Root Mean Square Error (NRMSE) con el fin de comparar y evaluar ambos métodos analíticos.

Fundamentals of Using Cracked Film Lithography to Pattern Transparent Conductive Metal Grids for Photovoltaics.

The fundamentals of using cracked film lithography (CFL) to fabricate metal grids for transparent contacts in solar cells were studied. The underlying physics of drying-induced cracks were well-predicted by an empirical correlation relating crack spacing to capillary pressure. CFL is primarily controlled by varying the crack template thickness, which establishes a three-way tradeoff between the areal density of cracks, crack width, and spacing between cracks, which in turn determine final grid transmittance, grid sheet resistance, and the semiconductor resistance for a given solar cell. Since CFL uses a lift-off process, an additional constraint is that the metal thickness must be less than 1/3 of the crack template thickness. The transmittance/grid sheet resistance/wire spacing tradeoffs measured in this work were used to calculate solar cell performance: CFL-patterned grids should outperform screen-printed grids for narrow cells (0.5-2 cm wide) and/or cells with high semiconductor sheet resistance (≥100 Ω/sq), making CFL attractive for monolithically integrated thin-film photovoltaic modules.

The History of Photovoltaics with Emphasis on CdTe Solar Cells and Modules

Among thin-film photovoltaic technology, cadmium telluride (CdTe) has achieved a truly impressive development that can commercially compete with silicon, which is still the king of the market. Solar cells made on a laboratory scale have reached efficiencies close to 22%, while modules made with fully automated in-line machines show efficiencies above 18%. This success represents the result of over 40 years of research, which led to effective and consolidated production processes. Based on a large literature survey on photovoltaics and on the results of research developed in our laboratories, we present the fabrication processes of both CdTe polycrystalline thin-film solar cells and photovoltaic modules. The most common substrates, the constituent layers, their interaction, the interfaces and the different “tricks” necessary to obtain highly efficient devices will be analyzed. A realistic industrial production process will be analytically described. Moreover, environmental aspects, end-of-life recycling and the life cycle assessment of CdTe-based modules will be deepened and discussed.

Development of a photovoltaic thermal facade system

A photovoltaic thermal (PVT) collector is made of a photovoltaic (PV) module and a solar thermal collector and thereby delivers electrical and thermal energy at the same time. These systems can contribute significantly to the renewable energy supply of residential, public, and commercial buildings. This paper gives insight into the development of a facade-integrated PVT system within the research project PVT Fassade. Thermal simulations evaluated useful operating conditions and efficiency-decreasing factors. Thus, 10 kg/(hm2) and 60 kg/(hm2) were identified as lower and upper limits for the mass flow and the losses by the internal heat transfer resistance of a 3.5 mm air layer between the PV module and the heat exchanger were determined to 35 % and 48 % for 10 and 60 kg/(hm2). These findings and structural, aesthetical, and general building law requirements were taken into consideration for the design of the facade-integrated PVT system. The functionality and feasibility of the developed system is shown through a constructed prototype facade where an intensive monitoring of the thermal and electrical performance of the PVT system is conducted. The performance of the PVT facade collector is described on the basis of an exemplary day of this monitoring. On this day, an area-specific thermal yield of 4.13 kWh/m2 with a temperature spread of up to 10.7 K is reached. At the same time, the thin film PV modules of the PVT system achieve an electrical yield increase of 2.5 % compared to a reference PV facade system.

Underwater performance of thin-film photovoltaic module immersed in shallow and deep waters along with possible applications

This article presents the experimental results of the underwater performance of amorphous silicon (a-Si) thin-film photovoltaic (TFPV) module. Electrical performance characteristics (current, voltage, power input, power output, and power conversion efficiency) of a-Si TFPV are evaluated considering the two installation conditions of Submerged Photovoltaics (SPV): shallow and deep waters. Experimental results showed that the a-Si TFPV could convert sun energy into electricity even in underwater environments. It is observed that there is a little drop in power outputs in deep waters than to shallow waters due to the variation in incident sunlight on to the photovoltaic (PV) module. Based on the observations, few possible applications for underwater PV system are explored. The article is concluded by highlighting few critical points for future research.

Characterization and modeling of reverse‐bias breakdown in Cu(In,Ga)Se2 photovoltaic devices

AbstractPartial shading of series‐connected thin‐film photovoltaic modules can force shaded cells into reverse bias, which can cause rapid and irreversible power loss and reduce the practical module lifespan. Unfortunately, this is a common occurrence in field‐deployed modules due to the myriad of environmental factors that can result in partial shading. In this work, we identify as‐grown nonuniformities in the Cu(In,Ga)Se2 (CIGS) absorber layers as the points of origin for the damage induced under reverse‐bias conditions. The structure and chemistry associated with inclusions and voids in the CIGS films cause these features to act as resistive heating elements in reverse‐bias conditions. This localized resistive heating provides the energy required to induce thermal runaway breakdown in the CIGS devices, resulting in damage to charge collection and reduced active area of a device. This mechanism is also described with a robust device model to connect the experimental observations with their physical origins.

Performance assessment of solar photovoltaic technologies under different climatic conditions in Brazil

Utility-scale photovoltaic (PV) generation is being ramped-up in Brazil in recent years, as a result of intense price reductions. Extreme operating temperatures, high humidity levels, and a blue-biased distribution of irradiance in comparison with the standard ASTM G-173 spectrum, lead to contrasting operational outputs of the various commercially-available PV technologies. The performance assessment of six different PV technologies installed at eight different climatic regions in Brazil is presented. This R&D project evaluates eight identical, 54 kWp Evaluation Sites (ESs), all with the following PV technologies: amorphous-silicon (a-Si), microcrystalline-silicon (μc-Si), cadmium-telluride (CdTe), copper-indium-gallium-diselenide (CIGS), mono- and multi-crystalline silicon (c-Si and m-Si). All installations operate at a fixed-tilt equal to the corresponding local latitude. Electrical and environmental parameters at all sites are measured continuously at 1-s intervals. Results show a detailed energy loss analysis for all technologies. Thin-film PV modules with a low temperature-coefficient of power presented superior performance. Crystalline silicon modules revealed intense degradation in areas with high relative humidity and temperature. Cloud-edge and cloud-enhancement effects of solar irradiance resulted in irradiance peaks of 1823 W/m2, with long overirradiance events which lasted many minutes over 1600 W/m2, resulting in frequent blowing of string fuses when manufacturers maximum fuse ratings were observed.

Fossil Fuels Environmental Challenges and the Role of Solar Photovoltaic Technology Advances in Fast Tracking Hybrid Renewable Energy System

The rise in global urbanization comes with sustainable development challenges, especially in lower-middle-income countries. In response to these urbanization and energy challenges, this study focuses on the roles of energy materials (EMs) advances on community-scale hybrid renewable energy systems (HRES). The study proposes the integration of energy material (EM) RD emits the least CO2 to the global CO2 emissions and yet endangered by climate change challenges and air pollution diseases. The study includes global responses to energy challenges, such as increase alternative energies share, with special attention to solar photovoltaic (PV) power generation technologies; policy framework; HRES and effects of PV materials advances on HRES. This study is of the view that a further breakthrough in the production of low-cost flexible thin film PV modules will facilitate energy trilemma accomplishment. The exploitation of the attributes of atomic layer deposition in manufacturing of thin film is seen as a potential future production technique, suitable for efficient flexible thin-film PV module production.

An accurate one-diode model suited to represent the current-voltage characteristics of crystalline and thin-film photovoltaic modules

In this paper a new one-diode model, conceived in order to be used to represent the current-voltage curves of both crystalline and thin-film photovoltaic modules, is presented. The model parameters are calculated from the information contained in the datasheets issued by manufactures by means of simple iterative procedures that do not require the assumption of simplifying hypotheses. Some innovative relations describing the dependence of the parameters from the solar irradiance and cell temperature are adopted in order to permit the model to reliably simulate the electrical behaviour of photovoltaic devices operating in real conditions.The ability of the model to calculate the current-voltage characteristics issued by manufacturers for values of the solar irradiance and cell temperature also far from the standard rating conditions was verified for various photovoltaic technologies, such as monocrystalline, polycrystalline, amorphous silicon, CIS, CIGS and tandem junction photovoltaic modules. The percentage ratio of the mean absolute difference of current to the rated current at the maximum power point ranges from 0.071% to 1.807%; the analogous ratio of power varies between 0.056% and 1.720%. A comparison with the results obtained with other recognised two-diode models is also presented.

Laser scribing of Cd2SnO4-based CdTe polycrystalline solar cells

Cd2SnO4-based CdTe solar cell is a potential technology to fabricate low cost and highly efficient thin film photovoltaic modules due to the excellent optical and electrical properties of Cd2SnO4 conductive transparent layer. However, the detailed research on patterning process is still deficient. In the present work, we developed laser scribing techniques to pattern the Cd2SnO4 thin film and the functional layers on top of the transparent conductive layer. By modifying the process and precisely adjusting the average energy density, the technique was further optimized to remove the upper layers completely without inducing any damage to the Cd2SnO4. The laser scribing process eliminates the exaggerated current density of CdTe solar cells contributed by the light absorption of the residual upper layers and as a result, device performance of the laser scribed cells could be precisely characterized. Besides, the isolative laser scribing of Cd2SnO4 layer and layers on top of Cd2SnO4 (window layer, absorption layer, back contact and metal electrode) is equal to the so-called P1, P2 and P3 steps in thin-film PV module production, which suggests that the whole set of laser scribing technique is applicable to the mass production of the Cd2SnO4-based CdTe solar cell modules.