Efficiency Of Photovoltaic Modules Research Articles

Expression for the electrical efficiency of photovoltaic modules in different photovoltaic thermal (PVT) configurations

In present communication, analytical expressions have been developed for electrical efficiency of an opaque (G-T) and a semitransparent (G-G) Photovoltaic panels in different photovoltaic thermal (PVT) configurations. Water and air are used for withdrawing the heat linked with the solar panel. Four configurations of opaque and semitransparent type PV modules have been discussed here. Namely case I: opaque solar panel where water flows above the module; case II: semitransparent solar panel where water flows above the panel; case III: opaque solar panel where air flows at beneath of the panel through duct and water flows above the panel and case IV: semitransparent solar panel where air flows at beneath of the panel through duct and water flows above the panel have been considered for the present study.It has been observed that case IV gives better results with related to the electrical energy generation among all four cases. Average electrical efficiency is increased by 2.29% and 4.17% respectively from case I to III and from case II–IV.

Comparison of maximum power point tracking techniques used in photovoltaic system

Among the various renewable energy sources, photovoltaic (PV) systems are experiencing a great expansion, due to their low polluting levels, the abundance of solar energy and the cost decreasing of PV technologies, attracting research and investments in the field. The maximum power generated in a PV panel varies according to irradiation and temperature. Since the conversion efficiency of photovoltaic modules is low, it is necessary to implement sophisticated control techniques for monitoring the maximum power point (MPPT). Maximum power point tracking techniques are automatic control algorithms that adjust power interfaces to achieve the maximum power generation, during variations in irradiation, temperature, and characteristics of the photovoltaic module. The purpose of the MPPT is to adjust the solar panel operating voltage near the maximum power point (MPP) according to environmental conditions. This technique has become an essential component in photovoltaic power system designs. This article presents comparison of the performance of various MPPT tracking methods in photovoltaic systems using the MATLAB/Simulink software and a comparative approach.

Эффективность гетероструктурных фотоэлектрических модулей на территории России и корректность методики выбора защитных аппаратов в их цепях

The aim of this study was to estimate the efficiency of photovoltaic modules (PVM) used at solar power plants (SPP) in the Russian Federation territory and to analyze how adequate the procedure adopted for selecting protective devices in the PVM circuits is. In carrying out the study, a solar power plant analysis model developed in the PVSyst software environment using the SolarGIS weather database was used. The currently effective State Standard GOST R 56978-2016 (IEC/TS 62548: 2013): Photovoltaic Arrays. Specifications, which stipulates the procedure for selecting protective devices in the PVM circuits, is analyzed for sufficiency of the considered in it factors influencing the levels of currents in these circuits. Based on the modeling results, the values of the specific generated power were obtained, and the capacity utilization factor (CUF) values of SPPs were calculated for various regions of Russia. The data obtained can be used in performing the feasibility studies of constructing solar power plants in the Russian Federation territory, including those to be used for the consumers own needs. This data may also be needed in elaborating/updating the methodology for selecting protective devices in the PVM circuits. A conclusion can be drawn based on the obtained study results that the PVM operation features high efficiency in the Russian Federation territory. There is also a need to develop a procedure for selecting protective devices in the PVM circuits that would take into account the influence of insolation level, temperature and degradation of modules on the levels of short circuit currents in their circuits.

Review of research, development and application of photovoltaic/thermal water systems

Abstract Among the many techniques for obtaining heat and electricity, solar thermal collectors, photovoltaic (PV) technology and PV/thermal (PV/T) technology have a very important place. The PV/T collectors enable the simultaneous conversion of solar radiation into thermal and electrical energy in a single device, with better space utilization and cost efficiency during construction. Specially designed PV/T collectors can replace the outer walls or roof covers and can be widely used in private houses, flat complexes, hospitals, schools, tourist and other objects for water heating and electrical energy generation. Due to their great application potential, hybrid collectors have been the subject of very intensive scientific research and technical development for many years. In this review article, the focus is on the research, development and application of the PV/T water systems in the last 10 years. The main task of researchers and manufacturers is to increase the efficiency of PV modules and thermal absorbers, using new materials and design types as well as their proper integration into the PV/T collector. It is also necessary to reduce the cost of these systems and make them more competitive in the market. In addition, the importance of PV/T systems is in providing energy in clean and environmentally friendly ways.

Annual energy losses due to partial shading in PV modules with cut wafer-based Si solar cells

To further improve the efficiency of the wafer-based silicon photovoltaic (PV) module, producers are introducing new module designs with cut-cells. Since smaller solar cells might be affected by partial shading even more and earlier than full-size cells, the energy performance simulations of partially shaded modules are crucial. A detailed shading analyses of partially shaded modules with different cut cell designs are presented not only on a single case scenario but on annual energy yield simulations using Spice, where a shading scenario over the whole module by the use of a new 3D shading horizon profile of selected shading objects is calculated. The annual simulations reveal that regardless the module design almost all cells in the module are confronted by reverse bias, which can deteriorate the module performance significantly. Simulation results with three different shading objects on five different module topologies at five locations showed that the best cut-cell module design depends strongly by the micro location and shading objects; however, in general the string of solar cells connected in series should be aligned with the shading shape around noontime as much as possible. A comprehensive annual energy performance evaluation of partially shaded cut-cell modules revealed; that with a correct cell layout of cut-cells in a PV module, the shading losses can be reduced by 30–50% if comparing to the standard PV module design.

Exhaustive Study of the PV Module Implemented in the Region of Annaba-Algeria

Abstract Algeria, like any other country, has drawn up its roadmap for the use and promotion of renewable energy sources. Motivated by its commitment to the international community in the fight against global warming and its possession of one of the largest solar fields in the world, a series of laws and institutions have consolidated this ambitious schedule. As known, both the climate and the geological area of Algeria take place among the foremost favoured countries in the field of solar energy. The present paper aims at proposing a simple model of photovoltaic module. The authors used Matlab/Simulink software to predict the current-voltage and power-voltage characteristics according to the influence of several factors, such as solar irradiance, cell temperature and series resistance, on the efficiency of photovoltaic module. The proposed experimental investigation can easily predict the curves (current-voltage and power-voltage) of a PV module, where both of simulation and practical results are identical. A single-crystal-line photovoltaic module was introduced close to Badji-Mokhtar Annaba University, Annaba (Algeria) to show the impact of climatic conditions in this coastal region and partial shading on characteristics.

Influence of temperature and irradiance on the different solar PV panel technologies

Abstract Tunisia has high solar radiation levels, which makes it suitable for the installation of photovoltaic (PV) systems. The design of these kinds of systems is an important step because there are many crucial factors to assess the PV module efficiency such as temperature, module types and solar radiation.This paper aims to give an analysis of the most influencing factor for selecting location. In fact, after estimating the PV panel inclination, the solar radiation and the temperature in “Zarzis” (southeastern of Tunisia), a comparative analysis among the different PV panel types was given. Additionally, to find which technologies are suitable for the climate conditions of this area, it is important to compare the effect of temperature and solar radiation on their performances.

Design and Modeling of the ANFIS-Based MPPT Controller for a Solar Photovoltaic System

Abstract Maximum power point tracking (MPPT) controllers play an important role in improving the efficiency of solar photovoltaic (SPV) modules. These controllers achieve maximum power transfer from PV modules through impedance matching between the PV modules and the load connected. Several MPPT techniques have been proposed for searching the optimal matching between the PV module and load resistance. These techniques vary in complexity, tracking speed, cost, accuracy, sensor, and hardware requirements. This paper presents the design and modeling of the adaptive neuro-fuzzy inference system (ANFIS)-based MPPT controller. The design consists of a PV module, ANFIS reference model, DC–DC boost converter, and the fuzzy logic (FL) power controller for generating the control signal for the converter. The performance of the proposed ANFIS-based MPPT controller is evaluated through simulations in the matlab/simulink environment. The simulation results demonstrated the effectiveness of the proposed technique since the controller can extract the maximum available power for both steady-state and varying weather conditions. Moreover, a comparative study between the proposed ANFIS-based MPPT controller and the commonly used, perturbation and observation (P&O) MPPT technique is presented. The simulation results reveal that the proposed ANFIS-based MPPT controller is more efficient than the P&O method since it shows a better dynamic response with few oscillations about the maximum power point (MPP). In addition, the proposed FL power controller for generating the duty cycle of the DC–DC boost converter also gave satisfying results for MPPT.

Thermal management of solar PV module by using hollow rectangular aluminum fins

Some of the recent challenges encountered in research and development of the solar photovoltaic (PV) industry include the decrease in electrical output efficiency of a conventional solar PV module due to the rise in its surface temperature. The main objective of this research work is to enhance and improve the electrical output efficiency of a common silicon-based solar PV module by lowering the operating temperature of the PV module, which was accomplished by attaching hollow rectangular aluminum tubes as a fin to the rear surface of the solar PV panel. The proposed geometrical configuration of tubes helped to increase the PV module heat transfer rate to the surrounding air by increasing the effective heat transfer area without increasing the overall weight of the PV module. In this experimental study, a comparative analysis has been presented for PV modules with fins and without fins. The results obtained from experiments demonstrated that the attached fins reduced the average temperature of the front and rear surfaces up to 8.97% and 8.41%, respectively. The cooling effect produced due to fins improved the open circuit voltage up to 12.97% and the electrical output efficiency up to 2.08%. Furthermore, the results are thoroughly compared with other published studies, which revealed that the proposed configuration is cost effective and structurally sound.

Algorithms for determining the maximum power point for photo modules at weather stations

The work is devoted to methods for increasing the energy efficiency of photovoltaic modules. Various algorithms for determining the maximum power points and their application to obtain the maximum possible efficiency when using solar panels are considered. The principles of the operation of algorithms are described; their advantages and disadvantages are indicated. Their comparison was carried out according to the main significant parameters. The most suitable algorithm for application at a weather station has been selected.

A bottom‐up cost analysis of silicon–perovskite tandem photovoltaics

AbstractStacking two photovoltaic (PV) cells to form a tandem structure can improve the efficiency of PV modules, and if achieved at sufficiently low cost, could dominate the PV market in the future. Rapid progress in silicon–perovskite tandem (SPT) cell efficiency has been made, so cost modelling is becoming important in analysing the commercial attractiveness of this approach. While previous cost modelling assumed idealised production processes, this work focuses first on six demonstrated SPT sequences using both homojunction and heterojunction bottom silicon cells, analysed in detail using a bottom‐up cost and uncertainty model and then compared with other reported SPT high‐efficiency cells. This identifies cost barriers in the perovskite cell, including high‐cost hole transport material (HTM) and electron transport layer (ETL) materials such as (2,2′,7,7′‐tetrakis[N,N‐di(4‐methoxyphenyl)amino]‐9,9′‐spirobifluorene [SPIRO] and [6,6]‐phenyl‐C61‐butyric acid methyl ester [PCBM]), and the use of spin coating which has a high wastage rate. Once these cost issues are solved, the silicon cell cost becomes important, and the use of lower cost homojunction cells with p‐type wafers can further reduce costs. A hypothetical medium term low‐cost sequence that combines the lowest cost parts of the analysed sequences and an improved perovskite deposition process has a projected likely cost of $1.50/cell, which if combined with 25% efficiency would give a favourable levelised cost of electricity (LCOE) compared with industry standard c‐Si cells. This analysis guides research directions to address cost issues in parallel with higher efficiencies in this technology area.

In-Plane Residual Stress Map for Solar PV Module: A Unified Approach Accounting the Manufacturing Process

The photovoltaic (PV) cell fracture reduces the efficiency of solar PV modules and the residual stresses generated in the silicon cells by various stages of manufacturing process are attributed as one of the primary reasons among others. In this study, a unified approach to investigate the residual stresses present across the PV module owing to differing material properties and thermal cycles during manufacturing process is attempted. In particular, an in-plane residual stress map for different layers of solar PV module and the stress jump across the layered structure arisen during the manufacturing process are quantified through finite element method by considering ethylene vinyl acetate encapsulant as a linear viscoelastic material. The maximum residual stress presence in the cell is observed during the encapsulant curing cycle of lamination process. The predictions on the stress pattern and magnitudes from the simulations collaborate well with the experimental observations reported in literature.

Effect of hot-arid climatic solar energy on monocrystalline photovoltaic performance in Pakistan

The domestic dwellings in Pakistan have predominantly implemented low-carbon strategies by harvesting solar energy using photo-voltaic (PV) panels as a long-term vision of low-carbon economy. Most of the urban areas in Pakistan stay hot and humid in an entire year. Consistent solar irradiation at higher temperatures is one of the major factors that affect the power generation performance of monocrystalline PV systems pose challenges to performance and degradation issues. Monocrystalline PV module efficiencies are declining and damaging under the continuous exposure to higher surface day-time temperatures in the different parts of the country. MATLAB simulations were performed based on the validated mathematical approach. This paper investigates the hot arid surface temperature impacts on the performance of PV modules during the summer and winter seasons in Pakistan. The investigations are performed examining the comparative output power generating performance of the PV system. This paper also investigates the influence of installations of PV-system in the North, South, East and West regions of Pakistan. It was examined that the northern areas of Pakistan are more suitable for maintaining the long-term durability of the PV system. Investigations are performed for the peak summer and peak winter days. During summer months, cooling strategies have to be implemented to overcome the heating effects whilst reducing degradation effect on installed PV-system.

Location-Specific Spectral and Thermal Effects in Tracking and Fixed Tilt Photovoltaic Systems.

SummaryThe efficiency of photovoltaic modules in the field is generally lower than the efficiency under standard testing conditions due to temperature and spectral effects. Using the latest spectral dataset available from the National Solar Radiation Database, we report spectral correction factors ranging from -2% to 1.3% of the produced energy for silicon modules depending on location and collector geometry. We find that spectral effects favor trackers if silicon modules are used, but favor a fixed tilt instead if perovskites or CdTe are used. In high-irradiance locations, the energy yield advantage of silicon-based trackers is underestimated by 0.4% if spectral sensitivity effects are neglected. As the photovoltaic market grows to a multi-terawatt size, these seemingly small effects are expected to have an economic impact equivalent to tens of billions of dollars in the next few decades, far outweighting the cost of the required research effort.

Monitoring complex for concentrator photovoltaic installation with a tracking system

The concentrator photovoltaic modules efficiency and their power generation are strongly dependent on the accuracy of their orientation by a tracking system towards the Sun. The more the solar cell power concentration ratio, the more stringent requirements are imposed on the module’s guidance system and tracking accuracy in the direction of the Sun. Effectiveness of the proposed technical solutions for the pair “module – tracking system” is usually verified as a result of the photovoltaic installation continuous monitoring. Such solutions for the specialized complex are presented, which provide for both control over the operating modes of the turning system used for the modules orientation to the Sun and tracking accuracy continuous monitoring, as well as regular monitoring of the modules output parameters in a photovoltaic installation.

Mono-crystalline silicon photovoltaic cells under different solar irradiation levels

In this research, partial shading influences on the efficiency of photovoltaic modules are explored. First, mathematical modeling of the Mono-crystalline PV module in case of various irradiation levels is presented. A performance assessment of a PV module by considering the electrical influence of the partial shading are then presented. The PVSYST software is used to explain the behavior of a cell or a group of shaded cells in a PV module. The tool allowed a good understanding of the functions of shunt diodes when one or more cells are shaded. Finally, this simulation is applied to the Algerian site of Béchar. In spite of shadowing and an inclination of 30°, the obtained results are good along the year with a maximum power point. The simulation has given the maximum of energy.

Characterization of Anti-Pollution Films by Thickness for Photovoltaic Modules That Can Be Applied in the Field

In this study, the characteristics of functional coating films were investigated to improve the anti-pollution properties and efficiency of PV (Photovoltaic) module according to the variation of coating film thickness. Functional coating was applied of a glass substrate, which was composed with the same material as PV module. Brush coating method was used for the coating process. We coated the functional film on the glass substrate 1, 2 and 3 times alternately in the horizontal and vertical directions to change the film thickness, and a hot air fan equipment was used as a heat treatment process for easy application to existing PV modules. The heat treatment process was performed for 2 minutes after the coating process using a hot air fan equipment. After coating and heat treatment, glass substrates were analyzed for the anti-pollution properties, contact angle, optical properties and the mechanical properties such as hardness and adhesion. The anti-pollution properties were identified through self-cleaning test. The contact angle of the functional coating film was measured by a contact angle analyzer, and the optical properties were measured via UV-visible spectroscopy, which can be used as an integrating sphere. The hardness of the functional film was measured by the standard hardness testing method using H-9H, F, HB and B-6B pencil. Also, the adhesion of the functional film was measured by the standard adhesion testing method.

Research on a New Type of Solar Photovoltaic Solar Thermal Integrated Louver Curtain Wall

This paper discusses the problem that the output efficiency of photovoltaic module decreases with the temperature rise of its environment. Combining photovoltaic power generation and photothermal technology, a new model of solar photovoltaic photothermal integrated louver curtain wall is proposed, which can not only have photovoltaic power generation function, but also create a good thermal environment for buildings and further reduce building energy consumption. The curtain wall model is established by computational fluid dynamics software. For the given initial parameters, the data of temperature field and flow field are obtained through simulation, and the influence of curtain wall system operation on the indoor thermal environment of the building is theoretically studied. It is found that the solar photovoltaic and photothermal integrated louver curtain wall not only has good thermoelectric benefits, but also improves the indoor thermal environment. Especially in summer and winter, the air conditioning load is reduced, which has a good building energy saving effect and provides a basis for actual building construction.

Towards improved cover glasses for photovoltaic devices

AbstractFor the solar energy industry to increase its competitiveness, there is a global drive to lower the cost of solar‐generated electricity. Photovoltaic (PV) module assembly is material‐demanding, and the cover glass constitutes a significant proportion of the cost. Currently, 3‐mm‐thick glass is the predominant cover material for PV modules, accounting for 10%–25% of the total cost. Here, we review the state‐of‐the‐art of cover glasses for PV modules and present our recent results for improvement of the glass. These improvements were demonstrated in terms of mechanical, chemical and optical properties by optimizing the glass composition, including addition of novel dopants, to produce cover glasses that can provide (i) enhanced UV protection of polymeric PV module components, potentially increasing module service lifetimes; (ii) re‐emission of a proportion of the absorbed UV photon energy as visible photons capable of being absorbed by the solar cells, thereby increasing PV module efficiencies and (iii) successful laboratory‐scale demonstration of proof of concept, with increases of 1%–6% in Isc and 1%–8% in Ipm. Improvements in both chemical and crack resistance of the cover glass were also achieved through modest chemical reformulation, highlighting what may be achievable within existing manufacturing technology constraints.

Decrease in Photovoltaic Module Efficiency Because of the Deposition of Pollutants

The deposition of pollutants on the surface of photovoltaic (PV) modules reduces the efficiency that can be achieved in given climatic conditions. This results in the loss of energy yield obtained from the solar installation. A number of factors determine the scale of this problem. The first of these is the amount of impurities deposited, the associated amount of precipitation, and the speed and direction of the wind. A second aspect is the type of pollution, and the composition and structure of the sludge, which depends on the location of the installation. The type of installation, either stationary or sun tracking, is essential because the angle of inclination of modules, depending on the latitude, will determine the amount of dust deposited, especially for stationary installations. The observed decrease in the efficiency of PV modules covered with dust equals 6–10% of the efficiency of a module free of impurities. This means that the user should maintain the module surface and schedule routine cleaning.