Efficiency Of Photovoltaic Modules Research Articles

Experimental Effect of the Impact of Stagnant Water on Solar Modules

In this research, an experimental study of the impact of stagnant water on solar modules is investigated. Two different experiments using two identical photovoltaic (PV) modules S1 and S2 were used for the study. In the first experiment, the PV module S1 was covered with stagnant water and the second PV module was unshielded with water. In the second experiment, the PV modules were swapped with S2 covered with stagnant water and S1 unshielded with water. The experiments were carried out under normal operating temperature of PV cells at the Department of Electrical Engineering, University of Nigeria, Nsukka on latitude 6:52 degrees north, longitude 7:23 degrees. Results obtained from the first experiment show that the efficiency and power output of S1 PV module decreased by 9.3% and 8.0% respectively when compared with that of S2 PV module. In the case of output voltage and current, it was found that shielding of PV module S1 with stagnant water caused an increase in the output voltage by 1.93% and a decrease in the output current by 10.26%. In the second experiment, the efficiency and Output power of PV module S2 decreased by 9.21% and 8.18% respectively when compared with the unshielded PV module S1. In the case of voltage and current, it was found that shielding of PV module S2 with stagnant water caused an increase in the Output voltage by 1.63% and decrease in the output current by 10.91%.

A study and comparative analysis of various materials based solar photovoltaic module to improve the output performance

Abstract Solar energy is a renewable source of energy. It has high cost for one time investment, not predictable in nature, need for storage of power required batteries and power losses are more, so low efficiency. In this paper the main focus is on different type of material used to manufacture solar photovoltaic panel and to increase the efficiency of solar photovoltaic module by resolving the problem of gathering of dust on the surface of solar panel which leads to reduction in power output (o/p) and also overall efficiency. The solar modules used in environments are full of dust which gets built-up on the module and sun light is also blocked to enter the cell. The o/p power decreases as much as 60%, if the module is dirty. For this various cleaning method are used like automatic cleaning, robotic cleaning, mechanical cleaning, manual cleaning and many more and in order to regularly clean the dust on the solar panel module. Several methods are discussed which are used to remove accumulated dust on its surface and maintain the solar power o/p

Oxidation: A dominant source for reduced efficiency of silicon solar photovoltaic modules

The quality of materials plays a decisive role on the life, performance and the return on investment (ROI) of engineering systems. The photovoltaic systems on-site suffer from climate conditions such as higher temperature, snow fall, humidity, rain, thunder storm, ultraviolet radiations and other environmental gasses and exhibit characteristic degradation. In this paper, we study the effects of oxidation on the degradation of the underlying semiconductor circuitry of the solar panels and the effect of aging on the life of the solar photovoltaic systems. Our research methodology is based on monitoring, testing and evaluating the real time power and efficiency using image analysis.

Defects Inspection in Polycrystalline Solar Cells Electroluminescence Images Using Deep Learning

Solar cells defects inspection plays an important role to ensure the efficiency and lifespan of photovoltaic modules. However, it is still an arduous task because of the diverse attributes of electroluminescence images, such as indiscriminative complex background with extremely unbalanced defects and various types of defects. In order to deal with these problems, this paper proposes a new precise and accurate defect inspection method for photovoltaic electroluminescence (EL) images. The proposed algorithm leverages the advantage of multi attention network to efficiently extract the most important features and neglect the nonessential features during training. Firstly, we designed a channel attention to exploit contextual representations and spatial attention to effectively suppress background noise. Secondly, we incorporate both attention networks into modified U-net architecture and named it multi attention U-net (MAU-net) to extract effective multiscale features for defects inspection. Finally, we propose a hybrid loss which combines focal loss and dice loss aiming to solve two problems: a) overcome the class imbalance problem, and b) allowing the network to train with irregular image labels for some complex defects. The proposed multi attention U-net is evaluated on real photovoltaic EL images datasets using 5-fold cross validation technique. Experimental results demonstrate that the proposed network can segment and detect various complex defects correctly. The proposed method achieved the mean intersection over-union (m-IOU) of 0.699 and F-measure of 0.799 which outperforms the previous methods.

Examining the spectral and thermal properties and electricity production efficiency of organic photovoltaic modules with regard to possible application as greenhouse cover

Examining the spectral and thermal properties and electricity production efficiency of organic photovoltaic modules with regard to possible application as greenhouse cover

Analysis of the cooling of PV modules with water on their efficiency

The article presents the results of research on the efficiency of photovoltaic modules cooled by water. The purpose of the experiment was to improve the working conditions of the solar cells. Lowering the cell temperature increases the power generated by the device. The decrease in the temperature of the PV module was obtained by pouring water on the upper surface of the cells, as rain imitation or a water film. The power of the cooled and non-cooled devices were compared. The best results were achieved by cooling cells with a water film since there were no water splashes. The continuous cooling of cells surface causes a 20% increase of device's power. During the test, the non-cooled module reached the maximum power of 172 W, while the cooled one - 205 W. Cooling the module resulted in an increase in power by 33 W. In addition, the temperature of the cells dropped to almost 25°C. At this time, the temperature of the non-cooled module was 45°C. The presented solution may be an interesting proposition for small installations. The solution can also be an alternative for cleaning the modules due to the improvement in the power of the module after the test in terms of their power before.

Diseño e implementación de un sistema seguidor solar inteligente a dos ejes para optimizar la producción de energía fotovoltaica con una lente de fresnel y un sistema de limpieza robotizado a bajo costo

Photovoltaic systems with Fresnel lenses are expensive, as well as technologically complex, due to their optical, mechanical and control components. In addition, all these systems are sensitive to operation and maintenance costs. This article proposes the use of commercial Fresnel lenses to improve the efficiency of photovoltaic modules, in conjunction with a fuzzy intelligent controlled solar tracking system with two-axis and a novel low-cost robotic cleaning system. The basic idea is that this system optimizes the production of electricity in an economically and technologically simple way. The technology of Arduino microcontrollers and fuzzy logic for control, as well as the geometry of Fresnel lenses, will be used to concentrate solar energy in a small area, not to mention that these optical devices have a low weight. The accumulated effect of energy production will be improved by a novel low cost robotic cleaning system. The alignment and perpendicularity of the impact of solar energy on photovoltaic cells must be maintained as much as possible and the performance of this system must be compared with other more expensive and technologically more complex commercial systems.

Experimental demonstration of voltage-matched two-terminal tandem minimodules

Mechanically stacked tandem solar cells are a potential near-term solution for increasing the efficiency of photovoltaic modules. Practical implementation requires an interconnection approach that maximizes efficiency and minimizes complexity and cost. Connecting the top and bottom cells in a voltage-matched configuration allows two-terminal modules to be fabricated without altering the cell design or processing methods. Here, we experimentally demonstrate two-terminal voltage-matched GaInP2 / Si minimodules. The two-terminal minimodules performed just as well as four terminal configurations when voltage-matching requirements were met. The magnitude of the efficiency loss experienced by the voltage-matched minimodule when voltage-matched conditions were not met depends on whether the voltage was constrained by the GaInP2 or Si cells. Monte Carlo simulations also indicate that the two-terminal voltage-matched tandems respond to small cell-to-cell parameter variations in a similar manner as four terminal tandems.

Spectral Filtering of Photovoltaic Cells using Novel Bio Filter: Silver Coated Hibiscus Extract using Butanol Solution

The adaptability of the solar photovoltaic cell is huge but not without its peculiar challenges. It has been reported that the patronage of photovoltaic (PV) in Africa is drastically dropping due to the dismal performance of PV in the first year of purchase. In this research, the bio-filter was proffered as an external solution to improving the efficiency and longevity of PV module. It was observed that the bio-filter improved the efficiency of the polycrystalline panel by 60%. This means that a good percentage of the solar IR radiation can be reflected from this proposed bio-filter. This research further affirms the significance of plants as a veritable tool to protect the PV panel. Hence, this bio-filter is adjudged to be cost-effective (i.e. affordable), universal usability and eco-friendly in both the long and short term.

A new IR and sprinkler based embedded controller directed robotic arm for automatic cleaning of solar panel

Purpose The purpose of this paper is to design and develop an IR and sprinkler based embedded controller operated robotic arm for automatic dust removal system to mitigate the dust effect on the solar panel surface, since dust accumulation normally affected by real weather conditions is one of the serious concern for the deterioration of photovoltaic (PV) system output. Design/methodology/approach The system is a wet cleaning device which provides a cheap silicon rubber-based wiping operation controlled by the pulse width modulation-operated motors of robotic arm. The IEEE 1149.1-compliant mixed signal-embedded platform of C8051F226DK is involved to command the complete system. Findings A prototype of 30 WP system is capable of producing an inspiring average value of 11.26 per cent in energy increase, 13.63 per cent in PV module efficiency and 85.20 per cent in performance ratio of the system after 73 days of cleaning in summer season. In addition, a total of 1,617.93 W power; 1,0516.55 Wh energy; and 350.55 KWh/KWP final yield was found during the entire cleaning period. Originality/value A novel technique of the implementation of IR sensor and sprinkler in dust mitigation is proposed in this paper. The IR sensor is used as a versatile object which can manage the robotic arm setting and control the automatic switching between cleaning and charging, as well as identify the thermal condition of solar panel for overheating.

Numerical analysis on thermal crack initiation due to non-homogeneous solder coating on the round strip interconnection of photo-voltaic modules

Solar energy is one of the most widely used renewable energy sources, with photo-voltaic (PV) solar cells/panels now utilized as an important energy source. The strip interconnection between solar cells (used for collecting current from solar cells) is a key PV module component; as poor interconnection reliability can lead to PV module failure. Multi-Busbar is a new type of interconnection which incorporates several round copper wires to help increase the energy conversion and transmission efficiency of PV modules and also to reduce the material costs. The non-homogeneity of the solder coating on the wires (resulting from manufacturing process faults), is one of the main factors that is responsible for the poor connections between the wire and the silver pads; which adversely impacts on the interconnection strength and long term reliability. This paper concerns an investigation of the effect of solder coating non-homogeneity on the thermo-mechanical response of round wires used for PV module interconnections. The study evaluates the two main parameters of non-homogeneity (out of centre value and direction), and also investigates the effect of geometrical parameters. The Extended Finite Element Method in ABAQUS software was used to determine the micro-crack initiation temperature and location for a given joint design. The results show that the cracking temperature is most affected by the direction of solder coating non-homogeneity and the downward vertical direction of out of centre positioning of copper in the solder coating leads to the most reduction in cracking temperature (up to 21%).

The Effect of the Superhydrophobic Film on the Generation Efficiency of Photovoltaic Modules Affected by Salt-Containing Dust Deposition

Dust deposition on the surface of photovoltaic (PV) modules causes undesirable effects, including shadowing and corrosion, which decrease power generation efficiency. A superhydrophobic film comprising nanometric silica modified by fluorosilane was prepared and coated on the surface of sample glasses. Natural dust deposition was simulated using laterite particles with a 25 μ m diameter, and the salt was dry-mixed with laterite particles using sodium chloride. In addition, condensation was simulated using a constant temperature and humidity incubator. PV module samples were irradiated by a solar simulator after the aforementioned simulation process, and the properties of the PV modules with different dust and salt contents were measured and analyzed by a solar module tester. The experimental results indicate that salt adversely affected the power generation efficiency of PV modules. And the superhydrophobic film can not only effectively remove the dust on the surface but also improve the power generation efficiency of PV modules.

Performance and Empirical Analysis of Photovoltaic Modules Made of Different Technologies Using Capacity Evaluation Method

Performance of 5 photovoltaic (PV) modules made of different technologies (monocrystalline silicon, polycrystalline silicon, amorphous silicon, copper indium selenide and heterojunction with intrinsic layer) is evaluated according to the short-term capacity evaluation method described in IEC TS 61724-2 standard. Measurements for the analysis are obtained from the data acquisition system developed by the Laboratory for Renewable Energy Sources at the Faculty of Electrical Engineering, Computer Science and Information Technology (FERIT) Osijek which is described in the paper. Results of the performance analysis according to the IEC TS 61724-2 standard indicate that the copper indium selenide PV module Solar Frontier SF150-S has the greatest performance, therefore it is the most suitable PV module for the micro-location of Osijek, Croatia with European humid continental climate. The lowest performance of all studied PV modules is achieved by polycrystalline silicon PV module Bisol BMU 250. Empirical analysis of the relations of various electrical and meteorological parameters is performed and dependencies are evaluated. In the last section, mathematical models of PV module efficiency in relation to the module temperature are derived based on empirical analysis of measurements.

Numerical Investigation of the Temperature Distribution in PCM-integrated Solar Modules

Both lifetime and efficiency of photovoltaic (PV) modules are negatively affected by high and/or strongly fluctuating temperatures. An approach to improve the thermal performance is to add a phase change material (PCM) to the layer composition of PV modules. In order to be able to determine design parameters of the PCM, e.g. layer thickness of the PCM, melting point or chemical composition, a mathematical 1D-model describing the transient temperature distribution across the module was developed. It considers all relevant heat transfer mechanisms – conduction, convection and radiation – as well as the melting-solidification processes of the PCM. The model is solved numerically by an iterative, implicit algorithm implemented in MATLAB. Input factors include geometrical parameters and material properties as well as time-dependent weather effects (irradiance, ambient temperature, wind speed and direction). To determine these factors, either locally measured data or values derived by empirical models from literature can be employed. The simulated temperature distribution was validated against measured temperatures with an average deviation of ±1.7 K and used as an input for a module lifetime model. The latter model showed that the integration of a PCM into the layer composition could increase the lifetime of a PV module by up to 10 y, yet at the cost of a lower energy generation which is reduced by about 12 % compared to PV modules without PCM.

Thermal Modeling of Opaque and Semi-Transparent Photovoltaic (PV) Module

Photovoltaic (PV) module is one of the simplest technologies to convert the solar energy into the useful electrical energy. In the present paper, an attempt has been made to develop a simplified analytical expression for solar cell temperature and solar cell electrical efficiency of opaque and semi-transparent photovoltaic module in the terms of design and climatic parameters. Based on the energy balance of opaque and semi-transparent PV module, the performance parameters, namely, solar cell temperature, solar cell electrical efficiency, module efficiency and electrical power output have been evaluated for a typical clear day of May month of New Delhi climatic condition data taken from IMD (Indian Meteorological Department), Pune, India. The numerical simulations have been made on the MATLAB software. Based on the numerical computation, the effect of back cover opaque and semitransparent tedlar of module on the performance parameters has been investigated. From the results and discussion, it is found that the performance of photovoltaic module is very sensitive to the module temperature. Further, it is concluded that the semi-transparent photovoltaic module is more efficient than the opaque one. Thus, by the application of semi-transparent PV module in the design of stand-alone and rooftop PV system, the overall energy requirement and performance can be improved for same occupied area.

Analysis of the influence of DC optimizers on photovoltaic production

Energy efficiency is a key element in the Smart Cities (SC), in which integration of renewable sources is a reality. Small-scale integration is usually implemented with photovoltaic (PV) and solar thermal energy. The shadows on the PV modules are a reality as they are originated by unavoidable buildings and obstacles existing in the cities. These shadows will cause the decrease in PV efficiency. Therefore, the increase in PV efficiency is essential. This increase in efficiency can be achieved by associating the DC-DC converters (DC-DC optimizers) with PV modules. This work presents and compares simulations and real results of the influence of DC-DC optimizers in the efficiency of PV modules. In addition, the work includes an economic study of the installation of DC optimizers considering three different electricity price scenarios.

Temperature distribution in a photovoltaic module at various mounting and wind conditions: A complete CFD modeling

In this study, a complete three-dimensional computational fluid dynamics simulation of fluid flow and heat transfer from a Photovoltaic (PV) module is developed. Since the electrical efficiency of photovoltaic modules is a function of its temperature, the present research tries to calculate the temperature distribution in the module by numerically solving the governing momentum and energy equations with the finite element method. The three dimensional wind flow field around the system is simulated in different geometrical and ambient conditions to account for realistic and nonuniform convection heat transfer from the module surfaces. The electrical output power is calculated as a function of PV module temperature and is modeled as a negative source term in the energy equation. Results show that the present method is very successful in predicting the temperature distribution and output power of photovoltaic modules at various geometrical and environmental conditions. Specifically, the effect of wind direction and tilt angle of the PV module is investigated. By increasing the tilt angle at wind velocities higher than 1 m/s, the average PV temperature increases by about 4 K; as a result, its efficiency decreases. The most favorable wind direction is 90° as a 3 K cooling in the average PV module temperature can be achieved. The proper choice of mounting orientation is also important, and it depends on the wind direction. In most cases, the horizontal mounting (i.e., the longer side of the panel is parallel to the ground) results in better cooling.

Effect of air quality and dust deposition on power generation performance of photovoltaic module on building roof

Due to the dust deposition on the surface of photovoltaic modules and the air pollution, the power generation performance of photovoltaic modules will be significantly affected. In order to quantitatively estimate the effect of air quality and dust deposition on the power generation performance of photovoltaic modules, a distributed photovoltaic system on a building roof in Shanghai is studied in this paper. Both artificial and natural dust deposition conditions are tested in terms of the influence of these factors on the power generation efficiency of photovoltaic modules. The variation of solar radiation intensity with PM2.5 concentration in Shanghai and the variation of photovoltaic module power generation capacity with PM2.5 concentration are tested and analyzed. The experimental results show that the surface dust of photovoltaic module reduces the power and efficiency of photovoltaic module. Experimental comparison between the dusty photovoltaic module and clean photovoltaic module shows that the dust on photovoltaic modules can reduce the power and efficiency significantly, where the highest power generation decrease is 35.226% and the highest power generation efficiency decrease is 5.546% as indicated in the experiments. Result shows that the amount of solar radiation is exponentially correlated to the PM2.5 concentration. Practical application: The influence of air quality and dust deposition on the performance of distributed PV modules is of vital importance under severe particulate pollution in Shanghai. This research helps predict the degradation of the photovoltaic system power generation efficiency, and determine whether to clean up the dust on the photovoltaic system according to accumulated PM concentration. This reduces the cost of cleaning of the dust on photovoltaic system. This study provides theoretical and experimental basis for the design of the building roof mounted solar photovoltaic system according to the local haze condition.

Optimal configuration of photovoltaic power plant using grey wolf optimizer: A comparative analysis considering CdTe and c-Si PV modules

At present, photovoltaic (PV) power plants are growing rapidly to respond to the high demand for energy. In this case, improving the levelized cost of electricity (LCOE) and produced energy for PV power plants is a complicated design tradeoff that involves several parameters, such as meteorological data variation, nonlinear operation of the PV plant components, inverter types, and PV module efficiency. Hence, this study intended to present the application of recent meta-heuristic techniques, namely, salp swarm algorithm (SSA), whale optimization algorithm (WOA), and grey wolf optimization (GWO), for two different cases. The technology of crystalline silicon (c-Si) and thin-film cadmium telluride (CdTe) PV modules is adopted for economic considerations and to determine the suitable PV module for the PV power plant. The optimization process is considered to minimize the LCOE and suggest the optimal sizing of PV modules and inverters on the basis of several candidates and their arrangement within the available area with optimal PV module tilt angle and orientation, as well as the optimal distribution of PV modules among the inverters. The new approaches have been compared with particle swarm optimization (PSO) algorithm. The proposed technique (GWO) shows significant results compared with other methods (PSO) in solving the optimal design of the PV power plant. The PV plant LCOE using thin-film (CdTe) has the lowest value compared to crystalline silicon (c-Si). The PV module efficiency and technology affect the overall dimension of the PV power plant.

Energy and economic efficiency performance assessment of a 28 kWp photovoltaic grid-connected system under desertic weather conditions in Algerian Sahara

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.