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For decades, society has been changing towards an energy mix that enhances the use of renewable sources and a more distributed generation of energy. The agricultural sector is included in this trend, which is why several studies are currently being carried out focused on the use of solar energy in greenhouses. This article aims to demonstrate the viability of a greenhouse that integrates, as a novelty, semi-transparent amorphous silicon photovoltaic (PV) glass (a-Si), covering the entire roof surface and the main sides of the greenhouse. The designed prototype is formed by a simple rectangular structure 12 m long and 2.5 m wide, with a monopitch roof, oriented to the southwest, and with a 35° inclination. The greenhouse is divided into two contiguous equal sections, each with an area of 15 m2, and physically separated by an interior partition transparent wall. The surface enclosure of one of the sections is made of conventional glass, and the one of the other, of PV glass. How the presence of semitransparent PV glass influences the growth of horticultural crops has been studied, finding that it slightly reduces the production of vegetal mass and accelerates the apical growth mechanism of heliophilic plants. However, from a statistical point of view, this influence is negligible, so it is concluded that the studied technology is viable for horticultural production. The energy balance carried out indicates that the energy produced by the PV system is greater than the energy consumed by the greenhouse, which shows that the greenhouse is completely viable and self-sufficient for sites with the adequate solar resource.
José-Ramón Aira; Sara Gallardo-Saavedra; Marcia Eugenio-Gozalbo; Víctor Alonso-Gómez; Miguel-Ángel Muñoz-García; Luis Hernández-Callejo. Analysis of the Viability of a Photovoltaic Greenhouse with Semi-Transparent Amorphous Silicon (a-Si) Glass. Agronomy 2021, 11, 1097 .
AMA StyleJosé-Ramón Aira, Sara Gallardo-Saavedra, Marcia Eugenio-Gozalbo, Víctor Alonso-Gómez, Miguel-Ángel Muñoz-García, Luis Hernández-Callejo. Analysis of the Viability of a Photovoltaic Greenhouse with Semi-Transparent Amorphous Silicon (a-Si) Glass. Agronomy. 2021; 11 (6):1097.
Chicago/Turabian StyleJosé-Ramón Aira; Sara Gallardo-Saavedra; Marcia Eugenio-Gozalbo; Víctor Alonso-Gómez; Miguel-Ángel Muñoz-García; Luis Hernández-Callejo. 2021. "Analysis of the Viability of a Photovoltaic Greenhouse with Semi-Transparent Amorphous Silicon (a-Si) Glass." Agronomy 11, no. 6: 1097.
Current–voltage (I–V) curve tracers are used for measuring voltage and current in photovoltaic (PV) modules. I–V curves allow identifying certain faults in the photovoltaic module, as well as quantifying the power performance of the device. I–V curve tracers are present in different topologies and configurations, by means of rheostats, capacitive loads, electronic loads, transistors, or by means of DC–DC converters. This article focuses on presenting all these configurations. The paper shows the electrical parameters to which the electronic elements of the equipment are exposed using LTSpice, facilitating the appropriate topology selection. Additionally, a comparison has been included between the different I–V tracers’ topologies, analyzing their advantages and disadvantages, considering different factors such as their flexibility, modularity, cost, precision, speed or rating, as well as the characteristics of the different DC–DC converters.
José Morales-Aragonés; Miguel Dávila-Sacoto; Luis González; Víctor Alonso-Gómez; Sara Gallardo-Saavedra; Luis Hernández-Callejo. A Review of I–V Tracers for Photovoltaic Modules: Topologies and Challenges. Electronics 2021, 10, 1283 .
AMA StyleJosé Morales-Aragonés, Miguel Dávila-Sacoto, Luis González, Víctor Alonso-Gómez, Sara Gallardo-Saavedra, Luis Hernández-Callejo. A Review of I–V Tracers for Photovoltaic Modules: Topologies and Challenges. Electronics. 2021; 10 (11):1283.
Chicago/Turabian StyleJosé Morales-Aragonés; Miguel Dávila-Sacoto; Luis González; Víctor Alonso-Gómez; Sara Gallardo-Saavedra; Luis Hernández-Callejo. 2021. "A Review of I–V Tracers for Photovoltaic Modules: Topologies and Challenges." Electronics 10, no. 11: 1283.
Solar Photovoltaic (PV) energy has experienced an important growth and prospect during the last decade due to the constant development of the technology and its high reliability, together with a drastic reduction in costs. This fact has favored both its large-scale implementation and small-scale Distributed Generation (DG). PV systems integrated into local distribution systems are considered to be one of the keys to a sustainable future built environment in Smart Cities (SC). Advanced Operation and Maintenance (O&M) of solar PV plants is necessary. Powerful and accurate data are usually obtained on-site by means of current-voltage (I-V) curves or electroluminescence (EL) images, with new equipment and methodologies recently proposed. In this work, authors present a comparison between five AI-based models to classify PV solar cells according to their state, using EL images at the PV solar cell level, while the cell I-V curves are used in the training phase to be able to classify the cells based on its production efficiency. This automatic classification of defective cells enormously facilitates the identification of defects for PV plant operators, decreasing the human labor and optimizing the defect location. In addition, this work presents a methodology for the selection of important variables for the training of a defective cell classifier.
Álvaro Pérez-Romero; Héctor Mateo-Romero; Sara Gallardo-Saavedra; Víctor Alonso-Gómez; María Alonso-García; Luis Hernández-Callejo. Evaluation of Artificial Intelligence-Based Models for Classifying Defective Photovoltaic Cells. Applied Sciences 2021, 11, 4226 .
AMA StyleÁlvaro Pérez-Romero, Héctor Mateo-Romero, Sara Gallardo-Saavedra, Víctor Alonso-Gómez, María Alonso-García, Luis Hernández-Callejo. Evaluation of Artificial Intelligence-Based Models for Classifying Defective Photovoltaic Cells. Applied Sciences. 2021; 11 (9):4226.
Chicago/Turabian StyleÁlvaro Pérez-Romero; Héctor Mateo-Romero; Sara Gallardo-Saavedra; Víctor Alonso-Gómez; María Alonso-García; Luis Hernández-Callejo. 2021. "Evaluation of Artificial Intelligence-Based Models for Classifying Defective Photovoltaic Cells." Applied Sciences 11, no. 9: 4226.
The measurement of current–voltage (I-V) curves of single photovoltaic (PV) modules is at this moment the most powerful technique regarding the monitoring and diagnostics of PV plants, providing accurate information about the possible failures or degradation at the module level. Automating these measurements and allowing them to be made online is strongly desirable in order to conceive a systematic tracking of plant health. Currently, I-V tracers present some drawbacks, such as being only for the string level, working offline, or being expensive. Facing this situation, the authors have developed two different low-cost online I-V tracers at the individual module level, which could allow for a cost-affordable future development of a fully automated environment for the tracking of the plant status. The first system proposed implements a completely distributed strategy, since all the electronics required for the I-V measurement are located within each of the modules and can be executed without a power line interruption. The second one uses a mixed strategy, where some common electronics are moved from PV modules to the inverter or combiner box and need an automated very short disconnection of the modules string under measurement. Experiments show that both strategies allow the tracing of individual panel I-V curves and sending of the data afterwards in numerical form to a central host with a minimum influence on the power production and with a low-cost design due to the simplicity of the electronics. A comparison between both strategies is exposed, and their costs are compared with the previous systems proposed in the literature, obtaining cost reductions of over 80–90% compared with actual commercial traces.
José Morales-Aragonés; Sara Gallardo-Saavedra; Víctor Alonso-Gómez; Francisco Sánchez-Pacheco; Miguel González; Oscar Martínez; Miguel Muñoz-García; María Alonso-García; Luis Hernández-Callejo. Low-Cost Electronics for Online I-V Tracing at Photovoltaic Module Level: Development of Two Strategies and Comparison between Them. Electronics 2021, 10, 671 .
AMA StyleJosé Morales-Aragonés, Sara Gallardo-Saavedra, Víctor Alonso-Gómez, Francisco Sánchez-Pacheco, Miguel González, Oscar Martínez, Miguel Muñoz-García, María Alonso-García, Luis Hernández-Callejo. Low-Cost Electronics for Online I-V Tracing at Photovoltaic Module Level: Development of Two Strategies and Comparison between Them. Electronics. 2021; 10 (6):671.
Chicago/Turabian StyleJosé Morales-Aragonés; Sara Gallardo-Saavedra; Víctor Alonso-Gómez; Francisco Sánchez-Pacheco; Miguel González; Oscar Martínez; Miguel Muñoz-García; María Alonso-García; Luis Hernández-Callejo. 2021. "Low-Cost Electronics for Online I-V Tracing at Photovoltaic Module Level: Development of Two Strategies and Comparison between Them." Electronics 10, no. 6: 671.
The inspection techniques for defects in photovoltaic modules are diverse. Among them, the inspection with measurements using current–voltage (I-V) curves is one of the most outstanding. I-V curves, which can be carried under illumination or in dark conditions, are widely used to detect certain defects in photovoltaic modules. In a traditional way, these measurements are carried out by disconnecting the photovoltaic module from the string inside the photovoltaic plant. In this work, the researchers propose a methodology to perform online dark I-V curves of modules in photovoltaic plants without the need of disconnecting them from the string. For this, a combination of electronic boards in the photovoltaic modules and a bidirectional inverter are employed. The results are highly promising, and this methodology could be widely used in upcoming photovoltaic plants.
José Morales-Aragonés; María Alonso-García; Sara Gallardo-Saavedra; Víctor Alonso-Gómez; José Balenzategui; Alberto Redondo-Plaza; Luis Hernández-Callejo. Online Distributed Measurement of Dark I-V Curves in Photovoltaic Plants. Applied Sciences 2021, 11, 1924 .
AMA StyleJosé Morales-Aragonés, María Alonso-García, Sara Gallardo-Saavedra, Víctor Alonso-Gómez, José Balenzategui, Alberto Redondo-Plaza, Luis Hernández-Callejo. Online Distributed Measurement of Dark I-V Curves in Photovoltaic Plants. Applied Sciences. 2021; 11 (4):1924.
Chicago/Turabian StyleJosé Morales-Aragonés; María Alonso-García; Sara Gallardo-Saavedra; Víctor Alonso-Gómez; José Balenzategui; Alberto Redondo-Plaza; Luis Hernández-Callejo. 2021. "Online Distributed Measurement of Dark I-V Curves in Photovoltaic Plants." Applied Sciences 11, no. 4: 1924.
Newly installed renewable power capacity has been increasing incredibly in recent years. For example, in 2018, 181 GW were installed worldwide. In this scenario, in which photovoltaic (PV) energy plays a leading role, it is essential for main players involved in PV plants to be able to identify the failure modes in PV modules in order to reduce investment risk, to focus their maintenance efforts on preventing those failures and to improve longevity and performance of PV plants. Among the different systems for defects detection, conventional infrared thermography (IRT) is the fastest and least expensive technique. It can be applied in illumination and in dark conditions, both indoor and outdoor. These two methods can provide complementary results for the same kind of defects, which is analyzed and characterized in this research. Novel investigation in PV systems propose the use of a power inverter with bidirectional power flow capability for PV plants maintenance, which extremely facilitates the electroluminescence (EL) inspections, as well as the outdoor IRT in the fourth quadrant.
Sara Gallardo-Saavedra; Luis Hernández-Callejo; María Del Carmen Alonso-García; Jesús Muñoz-Cruzado-Alba; Javier Ballestín-Fuertes. Infrared Thermography for the Detection and Characterization of Photovoltaic Defects: Comparison Between Illumination and Dark Conditions. Sensors 2020, 20, 4395 .
AMA StyleSara Gallardo-Saavedra, Luis Hernández-Callejo, María Del Carmen Alonso-García, Jesús Muñoz-Cruzado-Alba, Javier Ballestín-Fuertes. Infrared Thermography for the Detection and Characterization of Photovoltaic Defects: Comparison Between Illumination and Dark Conditions. Sensors. 2020; 20 (16):4395.
Chicago/Turabian StyleSara Gallardo-Saavedra; Luis Hernández-Callejo; María Del Carmen Alonso-García; Jesús Muñoz-Cruzado-Alba; Javier Ballestín-Fuertes. 2020. "Infrared Thermography for the Detection and Characterization of Photovoltaic Defects: Comparison Between Illumination and Dark Conditions." Sensors 20, no. 16: 4395.
The analysis of PV solar panels deterioration allows researchers to know the health status of a panel in order to determine the overall functioning of a PV solar farm. A part of this analysis is performed by thermography, generally using professional and expensive equipment. This article presents a validation for the use of low-cost thermal imaging cameras, reviewing the relative error that can be obtained through scattering, contour analysis and three-dimensional meshes. The procedure is validated by analysis of I-V/P-V curves and a temperature sensor matrix, reaching errors less than 10% with cameras with less than 500USD.
Miguel Alberto D´ávila-Sacoto; Luis Hernández-Callejo; Víctor Alonso Gómez; Sara Gallardo-Saavedra; Luis Gerardo González-Morales. Low-cost infrared thermography in aid of photovoltaic panels degradation research. Revista Facultad de Ingeniería Universidad de Antioquia 2020, 1 .
AMA StyleMiguel Alberto D´ávila-Sacoto, Luis Hernández-Callejo, Víctor Alonso Gómez, Sara Gallardo-Saavedra, Luis Gerardo González-Morales. Low-cost infrared thermography in aid of photovoltaic panels degradation research. Revista Facultad de Ingeniería Universidad de Antioquia. 2020; ():1.
Chicago/Turabian StyleMiguel Alberto D´ávila-Sacoto; Luis Hernández-Callejo; Víctor Alonso Gómez; Sara Gallardo-Saavedra; Luis Gerardo González-Morales. 2020. "Low-cost infrared thermography in aid of photovoltaic panels degradation research." Revista Facultad de Ingeniería Universidad de Antioquia , no. : 1.
Photovoltaic (PV) modules are the core of every PV system, representing the power generation and their operation will affect the overall plant performance. It is one of the elements within a PV site with the higher failure appearance, being essential their proper operation to produce reliable, efficient and safety energy. Quantitative analysis and characterization of manufacturing, soldering and breaking PV defects is performed by a combination of electroluminescence (EL), infrared thermography (IRT), electrical current voltage (I–V) curves and visual inspection. Equivalent-circuit model characterization and microscope inspection are also performed as additional techniques when they contribute to the defects characterization. A 60-cells polycrystalline module has been ad hoc manufactured for this research, with different defective and non-defective cells. All cells are accessible from the backside of the module and the module includes similar kinds of defects in the same bypass string. This paper characterizes different defects of PV modules to control, mitigate or eliminate their influence and being able to do a quality assessment of a whole PV module, relating the individual cells performance with the combination of defective and non-defective cells within the module strings, with the objective of determining their interaction and mismatch effects, apart from their discrete performance.
Sara Gallardo-Saavedra; Luis Hernández-Callejo; Carmen Alonso-Garcia; José Domingo Santos; José Ignacio Morales; Víctor Alonso-Gómez; Ángel Moretón-Fernández; Miguel Ángel González-Rebollo; Oscar Martínez-Sacristán. Nondestructive characterization of solar PV cells defects by means of electroluminescence, infrared thermography, I–V curves and visual tests: Experimental study and comparison. Energy 2020, 205, 117930 .
AMA StyleSara Gallardo-Saavedra, Luis Hernández-Callejo, Carmen Alonso-Garcia, José Domingo Santos, José Ignacio Morales, Víctor Alonso-Gómez, Ángel Moretón-Fernández, Miguel Ángel González-Rebollo, Oscar Martínez-Sacristán. Nondestructive characterization of solar PV cells defects by means of electroluminescence, infrared thermography, I–V curves and visual tests: Experimental study and comparison. Energy. 2020; 205 ():117930.
Chicago/Turabian StyleSara Gallardo-Saavedra; Luis Hernández-Callejo; Carmen Alonso-Garcia; José Domingo Santos; José Ignacio Morales; Víctor Alonso-Gómez; Ángel Moretón-Fernández; Miguel Ángel González-Rebollo; Oscar Martínez-Sacristán. 2020. "Nondestructive characterization of solar PV cells defects by means of electroluminescence, infrared thermography, I–V curves and visual tests: Experimental study and comparison." Energy 205, no. : 117930.
Nowadays, photovoltaic (PV) silicon plants dominate the growth in renewable energies generation. Utility-scale photovoltaic plants (USPVPs) have increased exponentially in size and power in the last decade and, therefore, it is crucial to develop optimum maintenance techniques. One of the most promising maintenance techniques is the study of electroluminescence (EL) images as a complement of infrared thermography (IRT) analysis. However, its high cost has prevented its use regularly up to date. This paper proposes a maintenance methodology to perform on-site EL inspections as efficiently as possible. First, current USPVP characteristics and the requirements to apply EL on them are studied. Next, an increase over the automation level by means of adding automatic elements in the current PV plant design is studied. The new elements and their configuration are explained, and a control strategy for applying this technique on large photovoltaic plants is developed. With the aim of getting on-site EL images on a real plant, a PV inverter has been developed to validate the proposed methodology on a small-scale solar plant. Both the electrical parameters measured during the tests and the images taken have been analysed. Finally, the implementation cost of the solution has been calculated and optimised. The results conclude the technical viability to perform on-site EL inspections on PV plants without the need to measure and analyse the panel defects out of the PV installation.
Javier Ballestín-Fuertes; Jesús Muñoz-Cruzado-Alba; José F. Sanz-Osorio; Luis Hernández-Callejo; Victor Alonso-Gómez; José Ignacio Morales-Aragones; Sara Gallardo-Saavedra; Oscar Martínez-Sacristan; Ángel Moretón-Fernández. Novel Utility-Scale Photovoltaic Plant Electroluminescence Maintenance Technique by Means of Bidirectional Power Inverter Controller. Applied Sciences 2020, 10, 3084 .
AMA StyleJavier Ballestín-Fuertes, Jesús Muñoz-Cruzado-Alba, José F. Sanz-Osorio, Luis Hernández-Callejo, Victor Alonso-Gómez, José Ignacio Morales-Aragones, Sara Gallardo-Saavedra, Oscar Martínez-Sacristan, Ángel Moretón-Fernández. Novel Utility-Scale Photovoltaic Plant Electroluminescence Maintenance Technique by Means of Bidirectional Power Inverter Controller. Applied Sciences. 2020; 10 (9):3084.
Chicago/Turabian StyleJavier Ballestín-Fuertes; Jesús Muñoz-Cruzado-Alba; José F. Sanz-Osorio; Luis Hernández-Callejo; Victor Alonso-Gómez; José Ignacio Morales-Aragones; Sara Gallardo-Saavedra; Oscar Martínez-Sacristan; Ángel Moretón-Fernández. 2020. "Novel Utility-Scale Photovoltaic Plant Electroluminescence Maintenance Technique by Means of Bidirectional Power Inverter Controller." Applied Sciences 10, no. 9: 3084.
One of the most important challenges to mitigate global climate change is to move towards replacing petroleum-based energy sources. In this idea, non-conventional renewable energy sources such as photovoltaic (PV) solar and wind power are the most used worldwide. In the case of the massification of PV solar generation systems due to its low cost, it has resulted in the use of large-scale supervision techniques that allow a quick and effective determination of the health status of its main components. This study, performs an analysis of the performance of different low-cost cameras for thermography. The analysis compares the accuracy of the thermal images obtained and the error is quantified by means of an image dispersion analysis in each of them. Three-dimensional meshes and contours figures are also made to determine the temperature of a faulty cell. The study shows that the performance obtained with low-cost cameras presents errors below 10% in costs and less than 0.015 USD/pixel.
Miguel Dávila-Sacoto; Luis Hernández-Callejo; Víctor Alonso-Gómez; Sara Gallardo-Saavedra; Luis G. González. Detecting Hot Spots in Photovoltaic Panels Using Low-Cost Thermal Cameras. Communications in Computer and Information Science 2020, 38 -53.
AMA StyleMiguel Dávila-Sacoto, Luis Hernández-Callejo, Víctor Alonso-Gómez, Sara Gallardo-Saavedra, Luis G. González. Detecting Hot Spots in Photovoltaic Panels Using Low-Cost Thermal Cameras. Communications in Computer and Information Science. 2020; ():38-53.
Chicago/Turabian StyleMiguel Dávila-Sacoto; Luis Hernández-Callejo; Víctor Alonso-Gómez; Sara Gallardo-Saavedra; Luis G. González. 2020. "Detecting Hot Spots in Photovoltaic Panels Using Low-Cost Thermal Cameras." Communications in Computer and Information Science , no. : 38-53.
Within this paper it is proposed the design and development of an instrument with extended capabilities for photovoltaic (PV) devices I/V tracing. Commercial instruments that measure I-V curves from PV devices are suitable for a wide range of applications. However, more specific research and measurements require developing customized equipment. Custom-made development provides flexibility, and allows to implement tailored algorithms and to have accurate control of obtained information. Full control offers better flexibility for testing and extends the measurement possibilities. Designed I-V tester is capable to measure low voltages and manages very low resistance load to provide short circuit current values with voltages close to zero.
Bhishma Hernández-Martínez; Sara Gallardo-Saavedra; Luís Hernández-Callejo; Víctor Alonso-Gómez; José Ignacio Morales-Aragonés. General Purpose I-V Tester Developed to Measure a Wide Range of Photovoltaic Systems. Communications in Computer and Information Science 2020, 135 -145.
AMA StyleBhishma Hernández-Martínez, Sara Gallardo-Saavedra, Luís Hernández-Callejo, Víctor Alonso-Gómez, José Ignacio Morales-Aragonés. General Purpose I-V Tester Developed to Measure a Wide Range of Photovoltaic Systems. Communications in Computer and Information Science. 2020; ():135-145.
Chicago/Turabian StyleBhishma Hernández-Martínez; Sara Gallardo-Saavedra; Luís Hernández-Callejo; Víctor Alonso-Gómez; José Ignacio Morales-Aragonés. 2020. "General Purpose I-V Tester Developed to Measure a Wide Range of Photovoltaic Systems." Communications in Computer and Information Science , no. : 135-145.
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.
Luis Hernández-Callejo; Sara Gallardo-Saavedra; Alejandro Diez-Cercadillo; Victor Alonso Gómez. Analysis of the influence of DC optimizers on photovoltaic production. Revista Facultad de Ingeniería Universidad de Antioquia 2019, 43 -55.
AMA StyleLuis Hernández-Callejo, Sara Gallardo-Saavedra, Alejandro Diez-Cercadillo, Victor Alonso Gómez. Analysis of the influence of DC optimizers on photovoltaic production. Revista Facultad de Ingeniería Universidad de Antioquia. 2019; (94):43-55.
Chicago/Turabian StyleLuis Hernández-Callejo; Sara Gallardo-Saavedra; Alejandro Diez-Cercadillo; Victor Alonso Gómez. 2019. "Analysis of the influence of DC optimizers on photovoltaic production." Revista Facultad de Ingeniería Universidad de Antioquia , no. 94: 43-55.
Being able to detect, to identify and to quantify the severity of defects that appear within photovoltaic modules is essential to constitute a reliable, efficient and safety system, avoiding energy losses, mismatches and safety issues. The main objective of this paper is to perform an in-depth, onsite study of 17,142 monocrystalline modules to detect every single existing defect, classifying them in different groups, studying the variance of the same kind of defect in different modules and the patterns of each group of thermal defects. Results can be useful in a subsequent development of a software to automatically detect if a module has an anomaly and its classification. Focusing on the results obtained, all faults detected have been classified in five different thermographic defects modes: hotspot in a cell, bypass circuit overheated, hotspot in the junction box, hotspot in the connection of the busbar to the junction box and whole module overheated. An analysis of patterns of the different defects is included, studiyng location within the module, size and temperature statistical results, as average temperature, standard deviation, maximum temperature, median and first and third quartile.
Sara Gallardo-Saavedra; Luis Hernández-Callejo; Oscar Duque-Perez. Analysis and characterization of PV module defects by thermographic inspection. Revista Facultad de Ingeniería Universidad de Antioquia 2019, 92 -104.
AMA StyleSara Gallardo-Saavedra, Luis Hernández-Callejo, Oscar Duque-Perez. Analysis and characterization of PV module defects by thermographic inspection. Revista Facultad de Ingeniería Universidad de Antioquia. 2019; (93):92-104.
Chicago/Turabian StyleSara Gallardo-Saavedra; Luis Hernández-Callejo; Oscar Duque-Perez. 2019. "Analysis and characterization of PV module defects by thermographic inspection." Revista Facultad de Ingeniería Universidad de Antioquia , no. 93: 92-104.
The greater challenge that researchers address and indicate while investigating about photovoltaic (PV) system failures during their Operation and Maintenance (O&M) is the lack of accessible reliable real quantitative data. For this reason, several publications have focused on this problem through a qualitative approach. However, this fact is one of the greater strengths of this paper, in which the quantitative information from the historical data of sixty-three PV plants portfolio in Italy and Spain has been accessible. Results obtained from the research provide essential information for main players involved in PV plants to identify failure modes and rates, in order to reduce investment risk and to focus their maintenance efforts on preventing those failures, improving longevity and performance of PV plants. The paper presents failure rates per PV Site and per kW, considering all portfolio and dividing it regarding five PV plants groups per size, distribution of failures per element, Mean Time Between Failures (MTBF), reparation times per affected element and the main failures modes examining each of the almost 100,000 complete alarms registered during the five years analyzed.
Sara Gallardo-Saavedra; Luis Hernández-Callejo; Oscar Duque-Pérez. Quantitative failure rates and modes analysis in photovoltaic plants. Energy 2019, 183, 825 -836.
AMA StyleSara Gallardo-Saavedra, Luis Hernández-Callejo, Oscar Duque-Pérez. Quantitative failure rates and modes analysis in photovoltaic plants. Energy. 2019; 183 ():825-836.
Chicago/Turabian StyleSara Gallardo-Saavedra; Luis Hernández-Callejo; Oscar Duque-Pérez. 2019. "Quantitative failure rates and modes analysis in photovoltaic plants." Energy 183, no. : 825-836.
Nowadays renewable energies are becoming more important in the generation of electricity. Fossil resources do not present a sustainable option for the future since they are non-renewable sources of energy that contribute to environmental pollution. Within the sources of renewable generation, photovoltaic energy is the most used, and this is due to a large number of solar resources existing throughout the planet. At present, the greatest advances in photovoltaic systems (regardless of the efficiency of different technologies) are focused on improved designs of photovoltaic systems, as well as optimal operation and maintenance. This work intends to make a review of the photovoltaic systems, where the design, operation and maintenance are the key points of these systems. Within the design, the critical components of the system and their own design are revised. Regarding the operation, it is reviewed the general operation and the operation of hybrid systems, as well as the power quality. Finally, in relation to the maintenance of PV systems, it has been studied their performance, thermography and electroluminescence, dirt, risks and failure modes.
Luis Hernández-Callejo; Sara Gallardo-Saavedra; Víctor Alonso Gómez. A review of photovoltaic systems: Design, operation and maintenance. Solar Energy 2019, 188, 426 -440.
AMA StyleLuis Hernández-Callejo, Sara Gallardo-Saavedra, Víctor Alonso Gómez. A review of photovoltaic systems: Design, operation and maintenance. Solar Energy. 2019; 188 ():426-440.
Chicago/Turabian StyleLuis Hernández-Callejo; Sara Gallardo-Saavedra; Víctor Alonso Gómez. 2019. "A review of photovoltaic systems: Design, operation and maintenance." Solar Energy 188, no. : 426-440.
The integration of renewable generation sources in cities is a reality. Specifically, photovoltaic technology is the most used (facades, roofs, urban spaces, etc.). The existence of buildings at different altitudes and other urban obstacles can cause shadows in the photovoltaic modules. These shadows will cause the decrease of photovoltaic efficiency. Therefore, the increase in photovoltaic efficiency is essential. This increase in efficiency can be achieved by associating DC-DC converters (DC-DC Optimizers) with photovoltaic modules. This work presents real results of the increase of efficiency of the photovoltaic modules, from the effect of the DC-DC Optimizers. In addition, the work shows simulations of the shadow effect on photovoltaic modules.
Luis Hernández-Callejo; Sara Gallardo-Saavedra; Alejandro Diez-Cercadillo; Víctor Alonso-Gómez. Study of the Influence of DC-DC Optimizers on PV-Energy Generation. Communications in Computer and Information Science 2019, 1 -17.
AMA StyleLuis Hernández-Callejo, Sara Gallardo-Saavedra, Alejandro Diez-Cercadillo, Víctor Alonso-Gómez. Study of the Influence of DC-DC Optimizers on PV-Energy Generation. Communications in Computer and Information Science. 2019; ():1-17.
Chicago/Turabian StyleLuis Hernández-Callejo; Sara Gallardo-Saavedra; Alejandro Diez-Cercadillo; Víctor Alonso-Gómez. 2019. "Study of the Influence of DC-DC Optimizers on PV-Energy Generation." Communications in Computer and Information Science , no. : 1-17.
Cities have evolved towards a new paradigm called Smart City (SC), which must evolve towards new intelligent infrastructures, which will integrate new sensors and advanced communications. Energy efficiency is key and fundamental in the SC. The transformation of energy systems due to the increased deployment of renewable energy is occurring mostly in the electricity sector, in which recent PV numbers show an undeniable landmark in renewable energies. Being able to detect, to identify and to quantify the severity of defects that appear within modules is essential to constitute a reliable, efficient and safety system, avoiding energy losses, mismatches and safety issues, especially in case of building integrated systems, as overheated anomalies could generate a fire risk or an electrical hazard. The main objective of this paper is to perform an in-depth on-site study of 17,142 monocrystalline modules to detect every single existing defect manually, classifying them in different groups, studying the variance of the same kind of defect in different modules and the patterns of each group of thermal defects that can be used to develop a software to automatically detect if a module has an anomaly and its classification. Attending the results obtained, all faults detected have been classified in five different thermographic defects modes: hotspot in a cell, bypass circuit overheated, hotspot in the junction box, hotspot in the connection of the busbar to the junction box and whole module overheated, with a percentage of occurrence of 75.35%, 10.79%, 6.93%, 6.84% and 0.09%, respectively.
Sara Gallardo-Saavedra; Luis Hernández-Callejo; Óscar Duque-Pérez. Analysis and Characterization of Thermographic Defects at the PV Module Level. Communications in Computer and Information Science 2019, 80 -93.
AMA StyleSara Gallardo-Saavedra, Luis Hernández-Callejo, Óscar Duque-Pérez. Analysis and Characterization of Thermographic Defects at the PV Module Level. Communications in Computer and Information Science. 2019; ():80-93.
Chicago/Turabian StyleSara Gallardo-Saavedra; Luis Hernández-Callejo; Óscar Duque-Pérez. 2019. "Analysis and Characterization of Thermographic Defects at the PV Module Level." Communications in Computer and Information Science , no. : 80-93.
Photogrammetric studies performed with Unmanned Aerial Vehicles (UAV) have recently become more popular as they present an interesting low-cost alternative. A novel application of thermography with UAVs has been validated during the last years: aerial thermography for inspection of photovoltaic plants as a useful diagnostic technique to assess performance of photovoltaic modules, superseding time-consuming traditional manual methods. This paper describes the current state of thermographic cameras and UAV technology, with the aim of examining the general principles of aerial thermographic measurement and required instrumentation, detailing the most important system aspects, discussing new developments and future trends in aerial thermography sensors and instrumentation, and evaluating them for specific application of aerial thermographic inspection of photovoltaic plants.
Sara Gallardo-Saavedra; Luis Hernández-Callejo; Oscar Duque-Perez. Technological review of the instrumentation used in aerial thermographic inspection of photovoltaic plants. Renewable and Sustainable Energy Reviews 2018, 93, 566 -579.
AMA StyleSara Gallardo-Saavedra, Luis Hernández-Callejo, Oscar Duque-Perez. Technological review of the instrumentation used in aerial thermographic inspection of photovoltaic plants. Renewable and Sustainable Energy Reviews. 2018; 93 ():566-579.
Chicago/Turabian StyleSara Gallardo-Saavedra; Luis Hernández-Callejo; Oscar Duque-Perez. 2018. "Technological review of the instrumentation used in aerial thermographic inspection of photovoltaic plants." Renewable and Sustainable Energy Reviews 93, no. : 566-579.
Photovoltaic energy is the renewable energy with the greatest growth and use. The tendency of the last years is directed towards the formation of increasingly larger plants, which implies that optimizing their maintenance is becoming extremely important. Aerial thermography has become a convenient quality assessment tool for photovoltaic power plants, being reliable, cost-effective and time-saving. However, it is essential to be aware of its strengths and limitations in order to apply and interpret the results correctly. This paper presents a study about the influence of Spatial Resolution of thermographic images on the severity of failures, evaluating the results obtained in a set of experimental aerial and manual inspections performed in a 3 MW PV plant in Spain. The research analyzes how aerial thermography should be arranged as a function of the thermographic camera and lens used with the aim of satisfying the resolution requirements. Indications about the correct procedure to perform aerial thermographic inspections are also provided.
Sara Gallardo-Saavedra; Luis Hernandez-Callejo; Oscar Duque-Perez; Luis Hermandez. Image Resolution Influence in Aerial Thermographic Inspections of Photovoltaic Plants. IEEE Transactions on Industrial Informatics 2018, 14, 5678 -5686.
AMA StyleSara Gallardo-Saavedra, Luis Hernandez-Callejo, Oscar Duque-Perez, Luis Hermandez. Image Resolution Influence in Aerial Thermographic Inspections of Photovoltaic Plants. IEEE Transactions on Industrial Informatics. 2018; 14 (12):5678-5686.
Chicago/Turabian StyleSara Gallardo-Saavedra; Luis Hernandez-Callejo; Oscar Duque-Perez; Luis Hermandez. 2018. "Image Resolution Influence in Aerial Thermographic Inspections of Photovoltaic Plants." IEEE Transactions on Industrial Informatics 14, no. 12: 5678-5686.
A simulation program for calculating the IV-curve for series connected PV-modules during partial shadowing has been developed and experimentally validated. The software used for modelling the modules is LTspice IV. The validation has been done by means of a comparative analysis using the experimental results obtained in a set of tests performed on the mono-crystalline modules of the Gävle University’s laboratory in Sweden. Experimental measurements were carried out in two groups. The first group is a string of six modules with bypass diodes while the second one corresponds to a single PV module. The simulation results of both groups demonstrated a remarkable agreement with the experimental data, which means that the designed model can be used for simulating the influence of shading on the power of a string. The model has been used for analysing the performance of strings of PV modules with shadows and the benefits of installing DC-DC optimizers or module inverters, that minimise the impact of shading, have been investigated.
Sara Gallardo-Saavedra; Björn Karlsson. Simulation, validation and analysis of shading effects on a PV system. Solar Energy 2018, 170, 828 -839.
AMA StyleSara Gallardo-Saavedra, Björn Karlsson. Simulation, validation and analysis of shading effects on a PV system. Solar Energy. 2018; 170 ():828-839.
Chicago/Turabian StyleSara Gallardo-Saavedra; Björn Karlsson. 2018. "Simulation, validation and analysis of shading effects on a PV system." Solar Energy 170, no. : 828-839.