Papers by Santiago Silvestre
Applied Physics Letters, 2001
Hydrogen incorporation in n-type Si-doped GaAs layers results in the neutralization of the active... more Hydrogen incorporation in n-type Si-doped GaAs layers results in the neutralization of the active dopants and a change of the conductivity along the growth direction. To characterize the active dopant concentration of doped GaAs layers containing hydrogen, we have used secondary ion mass spectroscopy and cross-sectional scanning tunneling microscopy. Spectroscopic measurements are performed as well as conductance images to visualize the variation of the conduction band-edge position. Such a variation, which is related to the concentration of Si–H complexes, allows the determination of the doping profile.
IEEE Conference Proceedings, 2016
A statistical-based approach for fault detection and diagnosis in a photovoltaic system. 2017 6th... more A statistical-based approach for fault detection and diagnosis in a photovoltaic system. 2017 6th International Conference on Systems and Control (ICSC).
IEEE Transactions on Industrial Electronics, 2017
Energies
Partial shading (PS) is a prevalent phenomenon that often affects photovoltaic (PV) installations... more Partial shading (PS) is a prevalent phenomenon that often affects photovoltaic (PV) installations, leads to the appearance of numerous peaks in the power-voltage characteristics of PV cells, caused by the uneven distribution of solar irradiance on the PV module surface, known as global and local maximum power point (GMPP and LMPP). In this paper, a new technique for achieving GMPP based on the dandelion optimizer (DO) algorithm is proposed, inspired by the movement of dandelion seeds in the wind. The proposed technique aimed to enhance the efficiency of power generation in PV systems, particularly under PS conditions. However, the DO-based MPPT is compared with other advanced maximum power point tracker (MPPT) algorithms, such as Particle Swarm Optimization (PSO), Grey Wolf Optimization (GWO), Artificial Bee Colony (ABC), Cuckoo Search Algorithm (CSA), and Bat Algorithm (BA). Simulation results establish the superiority and effectiveness of the used MPPT in terms of tracking efficie...
Journal of Energy Storage, 2022
Solar Energy, 2018
Photovoltaic (PV) modules are the main element responsible for the harvesting of solar radiation ... more Photovoltaic (PV) modules are the main element responsible for the harvesting of solar radiation in PV systems. Thus, their reliability and durability are two crucial factors to take in consideration for conceiving performant PV systems and improve the energy generation. The outdoor comportment analysis of different PV module technologies has gained an increased interest in last years in order to gain insight on the degradation of their performance. The present work studies the behaviour of three different PV modules based on cadmium telluride (CdTe), monocrystalline (c-Si) and multicrystalline silicon (mc-Si) technologies deployed outdoor in a humid continental climate. The period under scrutiny ranges from August 2015 to September 2017. Moreover, a new approach based on artificial neural network (ANN) was developed for the prediction of missing weather data. The obtained results showed that c-Si and mc-Si PV modules presented a slight performance degradation following the seasonal changes. The worst degradation rate of −5.55%/year was obtained for CdTe PV modules. Finally, the effects of the degradation on the I-V curve were proven by an indoor characterization of CdTe PV modules.
Solar Energy, 2017
The aim of this paper is to present an analysis of long term outdoor exposure of two thin film ph... more The aim of this paper is to present an analysis of long term outdoor exposure of two thin film photovoltaic (TFPV) module technologies deployed in semi-arid climate in Saida city located in Algeria. The TFPV modules are: a-Si:H/μc-Si:H (micromorph) and copper indium selenide (CIS). The TFPV modules were characterised by measuring their I-V curves during three years under the same outdoor climate conditions, where the measurement of weather parameters were also performed. The goal of the analysis is to evaluate the degradation rates of the TFPV modules in semi-arid climate. The analysis is based on two techniques, the effective peak power of PV module and power irradiance technique. It was found that TFPV modules CIS and micromorph exhibit a degradation rate of −2.34%/year and −1.73%/year respectively. The calculated degradation rate for CIS technology is higher than those reported in the literature for locations in Europe and lower than those for locations with hot and humid conditions. In the opposite the degradation rate of the micromorph was lower than those given in the literature.
Artificial Intelligence for Smart Photovoltaic Technologies
IEEE Systems Journal, 2021
Photovoltaic (PV) systems based on multistring configuration are the best effective solution, giv... more Photovoltaic (PV) systems based on multistring configuration are the best effective solution, given its advantages in terms of system availability, reliability, and energy efficiency. In this particular configuration each substring has its own dc-dc converter and a dedicated maximum power search algorithm which increase the cost and complexity. In this article, an efficient centralized global maximum power tracking (GMPPT) algorithm for multistring PV array subject to partial shading conditions is proposed. The algorithm is based on artificial bee colony (ABC) as an optimization approach to provide the optimal duty cycles allowing the extraction of the optimal global maximum power from each substring. In particular, the proposed approach allows significant reduction of the required sensors to only one pair of current and voltage sensors, at the common point of connection of the overall PV strings. The simulation study has been carried out under Cadence/Pspice and MATLAB/Simulink platforms on the I-V curves to confirm the effectiveness of the proposed algorithm when several shading patterns occur. In addition, complex shading pattern of a daily profile has been also carried out to demonstrate the GMPPT finding in dynamically variable conditions. Performance comparison against particle swarm optimization based maximum power point tracking algorithm and the traditional perturb and observe method has also been carried out. The obtained simulation and experimental results have shown the effectiveness and a good tracking capability of the proposed ABC algorithm in a multistring PV array configuration under uniform and nonuniform irradiance.
Data in Brief, 2016
Four years' behavioral data of thin-film single junction amorphous silicon (a-Si) photovoltaic (P... more Four years' behavioral data of thin-film single junction amorphous silicon (a-Si) photovoltaic (PV) modules installed in a relatively dry and sunny inland site with a Continental-Mediterranean climate (in the city of Jaén, Spain) are presented in this article. The shared data contributes to clarify how the Light Induced Degradation (LID) impacts the output power generated by the PV array, especially in the first days of exposure under outdoor conditions. Furthermore, a valuable methodology is provided in this data article permitting the assessment of the degradation rate and the stabilization period of the PV modules. Further discussions and interpretations concerning the data shared in this article can be found in the research paper "Characterization of degradation and evaluation of model parameters of amorphous silicon photovoltaic modules under outdoor long term exposure" (Kichou et al., 2016) [1].
2015 IEEE 42nd Photovoltaic Specialist Conference (PVSC), 2015
The particular opto-electronic properties of chemically synthesized colloidal nanoparticles can b... more The particular opto-electronic properties of chemically synthesized colloidal nanoparticles can be promising for functional materials, as those required for high efficient photovoltaic (PV) devices. In particular, appropriately-designed semiconductor colloids (quantum dots, QDs) can potentially allow sub-bandgap current generation in intermediate-band solar cells; while metal nanoparticles (MNPs) sustaining surface plasmons can provide both near and far-field light trapping to further boost the generated power. However, the incorporation of colloidal particles in inorganic PV materials is not trivial, therefore their implementation has so far been restricted to organic/polymeric based solar cells. In this work, PbS colloidal QDs have been incorporated in the intrinsic a-Si:H layer of HIT (substrate/a-Si:H hetero-junction) test structures. Both c-Si and GaAs substrates have been used, and in some cases colloidal Au NPs have also been included. The obtained devices are meant as probes to verify the feasibility of incorporating foreign nanoparticles in a cell structure and not as potentially efficient solar cells. Despite the radical novelties incorporated, the devices behaved similarly to the references, thus proving the compatibility of the proposed materials and processes.
The present work introduces a new method for the automatic detection of misbehaviours in photovol... more The present work introduces a new method for the automatic detection of misbehaviours in photovoltaic systems, minimizing the amount of data to be sensed. Different anomalous situations, including frame (ground) derivations, highly resistive connections, battery or panel short circuits, etc. are parameterised based on a model of the PV system under study. The same characteristic parameters are extracted from a reduced set of measures and, through a statistical analysis, a correspondence can be established which indicates the state of the physical system. In an experiment, several failures were introduced in a real system, including series resistances in connections, current leak to ground, short circuit of a battery vessel, disconnection of a branch of panels, and they were accurately detected by the algorithm.
Applied Soft Computing, 2015
Optimal energy harvesting is a key point in any photovoltaic system where economic and efficiency... more Optimal energy harvesting is a key point in any photovoltaic system where economic and efficiency aspects are strongly interrelated. In this paper a novel artificial bee colony optimization-based MPPT is proposed. The proposed Bee's algorithm allows the tracking of the maximal available power from a PV array under uniform and nonuniform illuminating conditions. A co-simulation methodology, combining Matlab/Simulink TM and Cadence/Pspice TM , has been used to verify the effectiveness of Bee's algorithm to track the MPP of serially connected PV modules subject to various shading patterns. In addition, a performance comparison with Particle Swarm Optimization (PSO) based MPPT algorithm is also presented. The experimental resuls have shown the validity of the developed heuristic algorithm and its good tracking capabilities under shading conditions.
Formación universitaria, 2008
Para su aplicación se han desarrollado modelos de todos los componentes de un sistema fotovoltaic... more Para su aplicación se han desarrollado modelos de todos los componentes de un sistema fotovoltaico. El método permite un rápido y fácil acceso a la evolución de las corrientes y tensiones del sistema. Este ejemplo de simulación permite a los estudiantes, un acceso cómodo y rápido al análisis y dimensionado de un sistema fotovoltaico, lo que facilita una visión global clara del comportamiento del sistema en distintos entornos de funcionamiento.
ABSTRACT Las células solares de banda intermedia se inventaron en España. Constituyen una propues... more ABSTRACT Las células solares de banda intermedia se inventaron en España. Constituyen una propuesta para aumentar la eficiencia de las células solares por encima del límite de Shockley y Queisser para células de un solo gap. El número de ideas para llevarlas a la práctica (desde la utilización de puntos cuánticos a la implantación selectiva de impurezas) se ha ido expandiendo a medida que nuestra comprensión ha ido aumentando. En este artículo repasamos el concepto de célula solar de banda intermedia y algunas de estas ideas para llevarla a la práctica.
Practical Handbook of Photovoltaics, 2003
ABSTRACT The output from the photovoltaic (PV) generator depends on solar radiation incident on t... more ABSTRACT The output from the photovoltaic (PV) generator depends on solar radiation incident on the inclined panels of the PV array. In some applications, the array orientation will be constrained by the nature of the support system: For example, the orientation of a building-integrated array will normally be dictated by the orientation of the roof or facade, where the array is to be installed. For a freestanding PV array, the most important consideration in deciding the array orientation is to maximize the energy collection by the inclined PV panels. This will frequently depend on the seasonal nature of the load. PV arrays that track the sun can collect a higher amount of energy than do those installed at a fixed tilt. The use of tracking is common for concentrator arrays—at least for appreciable concentration ratios—collect only the direct (beam) radiation. It is seen that, on a yearly basis, the energy capture by a tracking flat-plate system is increased by more than 30% over a fixed array at latitude inclination. At the same time however, that a tracking concentrator system will collect more energy than will a hat-plate system only in locations with predominantly clear skies.
Se presentan los resultados de la modalidad semipresencial en los estudios de Ingenieria Electron... more Se presentan los resultados de la modalidad semipresencial en los estudios de Ingenieria Electronica impartidos en la UPC como respuesta a que una mayoria de estudiantes simultanean los estudios con el trabajo profesional, y que dificulta su participacion en regimen presencial.
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Papers by Santiago Silvestre