Rozprawy doktorskie: „SOLAR PHOTOVOLTAIC PERFORMANCE”

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Ali, Rehan. "Effect of Solar Panel Cooling on Photovoltaic Performance". Thesis, Southern Illinois University at Edwardsville, 2014. http://pqdtopen.proquest.com/#viewpdf?dispub=1560782.

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One of the main problems in using the photovoltaic system is the low energy conversion efficiency of photovoltaic cells and, furthermore, during the long operational period of solar cells, their energy conversion efficiency decreases even more due to increase in operating cell temperature over a certain limit. One way of improving the efficiency of photovoltaic system is to maintain a low operating temperature by cooling it down during its operation period. This study compares the effects of cooling on the performance of photovoltaic system. Experiments are performed on the solar panel inclined at fixed 45° angle without active cooling initially to have a set of reference performance parameters for comparison. Afterwards, cooling of the solar panel is carried out using air and water, separately, as the cooling fluids. I-V tests and temperature tests, for all the cases, are performed for comparative analysis. The energy balance calculations showed that the experimental results are in conformity with the theoretical results. The results further showed that the cooling of photovoltaic system using water over the front surface enhances the performance even more as compared to air cooling of solar panel.

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BERNARDONI, Paolo. "Performance Optimization of Luminescent Solar Concentrator Photovoltaic Systems". Doctoral thesis, Università degli studi di Ferrara, 2016. http://hdl.handle.net/11392/2403385.

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Lo scopo di questo lavoro è l'ottimizzazione di sistemi fotovoltaici basati su concentratori solari a luminescenza, questi dispositivi non sono di nuova concezione ma, al momento, non è ancora disponibile un'analisi approfondita di sistemi dalle dimensioni adatte alla costruzione di dispositivi per integrazione architettonica. Per questa ragione, in questo lavoro, vengono analizzate le prestazioni di LSC costruiti impiegando diversi pigmenti, dimensioni e configurazioni ottiche così come l'effetto dell'auto-assorbimento sullo spettro di emissione del dispositivo, inoltre le differenti configurazioni ottiche sono state anche sottoposte a diverse condizioni di ombreggiamento così da identificare la più efficiente non solo in condizioni di lavoro ideali ma anche in uno scenario più simile alle reali condizioni di impiego di un dispositivo mirato all'integrazione architettonica. I prototipi sono stati costruiti a seguito di un ampio lavoro di simulazione del loro comportamento ottico mirato alla selezione delle configurazioni più promettenti, in particolare non è stata tenuta in considerazione solo l'efficienza ma anche la scalabilità del progetto e la facilità di assemblaggio: caratteristiche importanti per un prototipo che dovrebbe essere oggetto di trasferimento tecnologico dalla ricerca all'industria. Il primo risultato ottenuto è la dimostrazione della fattibilità di LSC di grandi dimensioni, ben oltre la comune dimensione da laboratorio di 5x5cm, inoltre, si è anche dimostrato come le prestazioni degli LSC possano essere incrementate con una contemporanea riduzione dei costi applicando pellicole riflettenti sui bordi così da uniformare il profilo di irradianza sulle celle. Tuttavia il risultato più significativo ottenuto è di aver dimostrato come sistemi con un ridotto numero di celle accoppiate a pellicole riflettenti poste sui lati rimanenti dell'LSC possano fornire un'efficienza maggiore rispetto ai sistemi tradizionali con le celle posizionate su quattro lati. Questi sistemi hanno anche mostrato una minore sensibilità agli effetti dell'ombreggiamento che rappresenta un risultato fondamentale per una tecnologia mirata all'integrazione architettonica, sottolineandone il progresso da argomento di ricerca a tecnologia con buone premesse di trasferimento verso l'industria.
The purpose of this work is the optimization of photovoltaic systems based on luminescent solar concentrators, these devices are not a new concept but, so far, a thorough analysis of the performance of LSC systems with sizes practical for building integration applications is missing. For this reason in this work the performances of LSCs based on different dyes, different sizes and various optical configurations were analysed as well as the effect of self-absorption on the output spectrum, moreover the performances of the systems with different optical configurations were analysed under some possible shading conditions in order to identify the most efficient and convenient design non only under an ideal working exposure but also in a real world scenario. The prototypes were built after an extensive work of simulation of their optical behaviour aimed at selecting the most promising designs, in particular not only the efficiency has been taken into account but also the scalability of the modules to larger or smaller sizes and the ease of assembly: important features for a design that should undergo a technology transfer from research to industrialization. The first result obtained is that the feasibility of large size LSCs (up to one square metre) well above the common laboratory size of 5×5cm have been demonstrated, moreover, it has also been shown that the performances of LSC systems can be improved, while lowering cost at the same time, by using reflective layers to get a more uniform irradiance profile on the cells. Anyway the most remarkable result obtained so far is having demonstrated that systems employing a small number of cells and a reflective film on the remaining sides of the LSC can yield a higher efficiency than a traditional design with cells placed on four sides, moreover these systems have also demonstrated a lower sensitivity to shading losses which represents a fundamental result for a technology targeted at the building integration, highlighting the progress of luminescent solar concentrators from a mere laboratory research topic to a promising industrialisable technology.

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Yandt, Mark. "Characterization and Performance Analysis of High Efficiency Solar Cells and Concentrating Photovoltaic Systems". Thesis, Université d'Ottawa / University of Ottawa, 2012. http://hdl.handle.net/10393/20535.

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As part of the SUNRISE project (Semiconductors Using Nanostructures for Record Increases in Solar-cell Efficiency), high efficiency, III-V semiconductor, quantum-dot-enhanced, triple-junction solar cells designed and manufactured by Cyrium Technologies Inc. were integrated into OPEL Solar, MK-I, Fresnel-lens-based, 550x concentrating modules carried on a dual axis tracker. Over its first year of operation 1.8 MWh of AC electrical energy was exported to the grid. Measurements of the direct and indirect components of the insolation, as well as the spectral irradiance of light incident on the demonstrator in Ottawa, Canada are presented. The system efficiency is measured and compared to that predicted by a system model to identify loss mechanisms so that they can be minimized in future deployments.

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Goss, Brian. "Design process optimisation of solar photovoltaic systems". Thesis, Loughborough University, 2015. https://dspace.lboro.ac.uk/2134/19418.

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The design processes for solar photovoltaic (PV) systems is improved to achieve higher reliability and reduced levelised cost of energy (LCOE) throughout this thesis. The design processes currently used in the development of PV systems are reviewed. This review process included embedding the author in a project to deliver four rooftop PV systems which totalled a megawatt of installed generating capacity, which at the time represented very significant system sizes. The processes used in this are analysed to identify improvement potential. Shortcomings are identified in three main areas: safety assurance, design process integration and financial optimisation. Better design process integration is required because data is not readily exchanged between the industry standard software tools. There is also a lack of clarity about how to optimise design decisions with respect to factors such as shading and cable size. Financial optimisation is identified as a challenge because current software tools facilitate optimising for maximum output or minimum cost, but do not readily optimise for minimum levelised cost of energy which is the primary objective in striving for grid parity. To achieve improved design process integration and financial optimisation, a new modelling framework with the working title SolaSIM is conceived to accurately model the performance of solar photovoltaic systems. This framework is developed for grid connected systems operating in the UK climate, but it could readily be adapted for other climates with appropriate weather data. This software development was conducted using an overarching systems engineering approach from design and architecture through to verification and validation. Within this SolaSIM framework, the impact of shading on array and inverter efficiency is identified as a significant area of uncertainty. A novel method for the calculation of shaded irradiance on each cell of an array with high computational efficiency is presented. The shading sub-model is validated against outdoor measurements with a modelling accuracy within one percent. Final verification of the over-arching SolaSIM framework found that it satisfied the requirements which were identified and actioned. The author installed the new CREST outdoor measurement system version 4 (COMS4). COMS4 is a calibrated system which measures 26 PV devices simultaneously. Validation of SolaSIM models against COMS4 found the modelling error to be within the 4% accuracy target except two sub-systems which had electronic faults. The model is validated against PV systems and found to be within the specified limits.

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Mehrtash, Mostafa. "Performance evaluation of solar tracking photovoltaic systems operating in Canada". Mémoire, École de technologie supérieure, 2013. http://espace.etsmtl.ca/1138/1/MEHRTASH_Mostafa.pdf.

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En 2011, la capacité totale installée du Photovoltaïque au Canada était de 289 MW et elle pourrait atteindre entre 9 et 15 GW d'ici 2025. Selon des études antérieures, des systèmes de suivi solaires PV peuvent capturer 20% à 50% plus de rayonnement solaire que les systèmes fixes. Un suiveur solaire est un dispositif qui maintient les panneaux photovoltaïques perpendiculaires aux rayons du soleil. Il y a un manque de connaissances sur la performance des systèmes solaires photovoltaïques de suivi d'exploitation dans les conditions météorologiques sévères du Canada. Trois objectifs principaux ont été définis pour cette recherche. Le premier objectif est l'évaluation des performances en fonction de la stratégie de suivi pour les systèmes PV. Cet objectif est atteint par la simulation et l'analyse de quatre systèmes PV: horizontal fixe, incliné fixe, suivi selon un axe et suivi selon deux axes. Ces systèmes sont analysés au cours des périodes annuelles, mensuelles et journalières. Quatre villes avec des conditions météorologiques différentes ont été étudiées: Montréal (Canada), Casablanca (Maroc), Ouagadougou (Burkina Faso), et Olympia (USA). Les résultats obtenus à partir de simulations montrent que les systèmes de suivi selon deux axes présentent les rendements les plus élevés dans tous les endroits choisis. Le deuxième objectif est de déterminer l'orientation optimale d'un système d'exploitation PV dans des conditions climatiques du Canada. Cet objectif est atteint en enquêtant sur la météo et les conditions environnementales du Canada qui touchent les systèmes PV, y compris les basses températures en hiver et le rayonnement réfléchi par la neige (effet albédo). Le rayonnement réfléchi par la neige cumulée sur le sol entraîne une augmentation de l'irradiation des panneaux jusqu'à 4,1%, 5,6% et 6,9% pour les systèmes inclinées, avec suivi selon un axe, et avec suivi selon deux axes pendant l'hiver, respectivement. Les systèmes de suivis selon un axe et deux axes reçoivent 28% et 33% de plus de rayonnement solaire que le système incliné sur un an. De plus, le suivi du soleil pourrait précipiter le phénomène de fusion de la glace et de la neige accumulée sur les panneaux photovoltaïques. L'objectif final de cette thèse est le choix de la méthode de suivi optimale pour le Canada. Cet objectif est atteint par l'analyse de diverses orientations des systèmes PV dans les jours typiques: une journée d'hiver claire, une claire journée d'été, et une journée nuageuse d’hiver et d’été. Selon les analyses quotidiennes, le suivi du soleil est efficace les jours de soleil direct (clairs), contre-productif les jours nuageux, et dépend de l'indice de clarté dans les jours très nuageux. Ces résultats sont corroborés par des recherches antérieures. Les résultats permettent de proposer une méthode qui permet de suivre le soleil dans des conditions claires et d’aller à la position horizontale dans des conditions nuageuses. En conditions nuageuses partielles, la stratégie de suivi à adopter dépend de l'indice de clarté et de rayonnement réfléchi par le sol.

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Macabebe, Erees Queen Barrido. "Investigation of device and performance parameters of photovoltaic devices". Thesis, Nelson Mandela Metropolitan University, 2009. http://hdl.handle.net/10948/1003.

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In order to investigate the influence of parasitic resistances, saturation current and diode ideality factor on the performance of photovoltaic devices, parameter extraction routines employing the standard iteration (SI) method and the particle swarm optimization (PSO) method were developed to extract the series resistance, shunt resistance, saturation current and ideality factor from the I-V characteristics of solar cells and PV modules. The well-known one- and two-diode models were used to describe the behavior of the I-V curve and the parameters of the models were determined by approximation and iteration techniques. The SI and the PSO extraction programmes were used to assess the suitability of the one- and the two-diode solar cell models in describing the I-V characteristics of mono- and multicrystalline silicon solar cells, CISS- and CIGSS-based solar cells. This exercise revealed that the two-diode model provides more information regarding the different processes involved in solar cell operation. Between the two methods developed, the PSO method is faster, yielded fitted curves with lower standard deviation of residuals and, therefore, was the preferred extraction method. The PSO method was then used to extract the device parameters of CISS-based solar cells with the CISS layer selenized under different selenization process conditions and CIGSS-based solar cells with varying i-ZnO layer thickness. For the CISS-based solar cells, the detrimental effect of parasitic resistances on device performance increased when the temperature and duration of the selenization process was increased. For the CIGSS-based devices, photogeneration improved with increasing i-ZnO layer thickness. At high forward bias, bulk recombination and/or tunneling-assisted recombination were the dominant processes affecting the I-V characteristics of the devices. v Lastly, device and performance parameters of mono-, multicrystalline silicon and CIS modules derived from I-V characteristics obtained under dark and illuminated conditions were analyzed considering the effects of temperature on the performance of the devices. Results showed that the effects of parasitic resistances are greater under illumination and, under outdoor conditions, the values further declined due to increasing temperature. The saturation current and ideality factor also increased under outdoor conditions which suggest increased recombination and, coupled with the adverse effects of parasitic resistances, these factors result in lower FF and lower maximum power point. Analysis performed on crystalline silicon and thin film devices utilized in this study revealed that parameter extraction from I-V characteristics of photovoltaic devices and, in particular, the implementation of PSO in solar cell device parameter extraction developed in this work is a useful characterization technique.

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Tatsiankou, Viktar. "Instrumentation Development for Site-Specific Prediction of Spectral Effects on Concentrated Photovoltaic System Performance". Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31222.

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The description of a novel device to measure the spectral direct normal irradiance is presented. The solar spectral irradiance meter (SSIM) was designed at the University of Ottawa as a cost-effective alternative to a prohibitively expensive field spectroradiometer (FSR). The latter measures highly-varying and location-dependent solar spectrum, which is essential for accurate characterization of a concentrating photovoltaic system’s performance. The SSIM measures solar spectral irradiance in several narrow wavelength bands with a combination of photodiodes with integrated interference filters. This device performs spectral measurements at a fraction of the cost of a FSR, but additional post-processing is required to deduce the solar spectrum. The model was developed to take the SSIM’s inputs and reconstruct the solar spectrum in 280–4000 nm range. It resolves major atmospheric processes, such as air mass changes, Rayleigh scattering, aerosol extinction, ozone and water vapour absorptions. The SSIM was installed at the University of Ottawa’s CPV testing facility in September, 2013. The device gathered six months of data from October, 2013 to March, 2014. The mean difference between the SSIM and the Eppley pyrheliometer was within ±1.5% for cloudless periods in October, 2013. However, interference filter degradation and condensation negatively affected the performance of the SSIM. Future design changes will improve the longterm reliability of the next generation SSIMs.

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Crozier, Jacqueline Louise. "Characterisation of performance limiting defects in photovoltaic devices using electroluminescence and related techniques". Thesis, Nelson Mandela Metropolitan University, 2015. http://hdl.handle.net/10948/11004.

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Solar cells allow the energy from the sun to be converted into electrical energy; this makes solar energy an environmentally friendly, sustainable alternative to fossil fuel energy sources. Solar cells are connected together in a photovoltaic (PV) module to provide the higher current, voltage and power outputs necessary for electrical applications. However, the performance of PV modules can limited by the degradation and defects. PV modules can be characterised using various opto-electronic techniques, each providing information about the performance of the module. The current-voltage (I-V) characteristic curve of a module being the most commonly used characterisation technique. The I-V curve is typically measured in outdoor, fully illuminated, conditions. This allows performance parameters such as short circuit current (ISC), open circuit voltage (VOC) and maximum power (PMAX) to be determined. However, it can be difficult to determine the root cause of the performance drop from the I-V curve alone. Electroluminescence (EL) is a module characterisation technique that allows defects and failures in PV modules to be successfully identified. This study investigates the characterisation of solar cells and photovoltaic modules using EL. EL occurs when a solar cell or module is forward biased and the injected electron-hole pairs recombine radiatively. The intensity of the emitted EL is related the applied voltage and the material properties. EL imaging is a useful characterisation technique in identifying module defects and failures. Defects such as micro-cracks, broken contact fingers and fractures are detected in EL images as well as material features such as grain boundaries. The common defects in crystalline silicon are catalogued and the possible causes are discussed. An experimental setup was developed in order to systematically take a high resolution EL image of every cell in the module and record the applied voltage and current. This produces a very detailed, clear, image of each cell with a pixel size in the micrometre range. This process is time consuming to acquire an EL image of an entire module so alternatively a different setup can be used and an EL image of a whole module can be captured in a single frame with an increased pixel size in the millimetre range. For EL imaging a silicon charge-coupled device (CCD) camera was used because it has very good spatial resolution however this sensor is only sensitive to wavelength in the range of 300-1200 nm. There is an overlap in wavelengths from about 900 to 1100 nm allowing the EL emitted from silicon solar cells to be detected. In conjunction with the high-resolution EL system an image processing program was developed to crop, adjust and align the images so only the relevant cell was included. This program also automatically detects certain defects that have a regular shape. Micro-cracks, broken fingers and striation rings are automatically identified. The program has an adjustable sensitivity to identify small or large defects. Defective cells are distinguished from undamaged cells by comparing the binary images to the ideal, undamaged cell. The current-voltage curves and the performance parameters of modules were compared with the EL images in order to discuss and identify power limiting defects. Features that remove significant portions of the cell from electrical contact such as micro-cracks are shown to have a larger effect of the performance of the module. Other features such as broken contact fingers, contact forming failures and striation rings do not significantly lower the performance of the module. Thus an understanding of how different features affect the module performance is important in order to correctly interpret the EL results. The intensity of the luminescence emitted is related to the applied voltage and the quantum efficiency of the cell material. The spectrum of the emitted luminescence was modelled and related to the recombination properties of the cell such as surface recombination velocity and minority carrier diffusion length/lifetime. In this study the emitted spectrum was modelled and the effects of recombination properties of the cell on the emitted spectrum were examined. The spectrum of the detected EL was modelled, dependent on the sensitivity of the camera, the transmission of the filters and the emitted photon flux. The integration of short-pass filters into the experimental setup in order to isolate short-wavelength luminescence was discussed. There is a proportional relationship between the intensity of the emitted EL and the local junction voltage. Resistive losses like series and shunt resistances lower the applied voltage and thus affect the EL image. The voltage dependence was assessed by comparing EL images taken at different applied biases. Analysis of the variation in EL intensity with voltage was successful in determining the origin of certain features in an EL image. Certain defects, those that are related to series resistance or shunting are highly voltage dependent. When a feature has little or no dependence on voltage then the defect could be in the laminate layers and not in the cell material. The results of this study allow for in-depth analysis of the defects found in PV modules using the high resolution EL imaging system and the image processing routine. The development of an image processing routine allows the interpretation of the EL image to be done automatically, resulting in a faster and more efficient process. By understanding the defects visible in the EL image, the test is more meaningful and allows the results to be used to predict module performance and potential failures.

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Shen, Ming. "Distributed Solar Photovoltaic Grid Integration System : A Case Study for Performance". PDXScholar, 2012. https://pdxscholar.library.pdx.edu/open_access_etds/945.

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The needs to the sustainable development of electricity, energy efficiency improvement, and environment pollution reduction have favored the development of distributed generation (DG). But the problems come with increasing DG penetration in distribution networks. This thesis presents the Solar Energy Grid Integration System (SEGIS) Stage III project done by Portland General Electric (PGE), Advanced Energy, Sandia National Lab on a PGE selected distribution feeder. The feeder has six monitored commercial solar PV systems connected. The total power output from the PV systems has the potential to reach 30% of the feeder load. The author analyzes the performance of the solar feeder on both generation and voltage effects. As a project report, it introduced a new islanding detection done by other team members to give an islanding solution of future high penetration distribution networks. At last, the author describes micro-grid and grid support concepts in a SEGIS concept paper with some examples.

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Kang, Moon Hee. "Development of high-efficiency silicon solar cells and modeling the impact of system parameters on levelized cost of electricity". Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/47647.

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The objective of this thesis is to develop low-cost high-efficiency crystalline silicon solar cells which are at the right intersection of cost and performance to make photovoltaics (PV) affordable. The goal was addressed by improving the optical and electrical performance of silicon solar cells through process optimization, device modeling, clever cell design, fundamental understanding, and minimization of loss mechanisms. To define the right intersection of cost and performance, analytical models to assess the premium or value associated with efficiency, temperature coefficient, balance of system cost, and solar insolation were developed and detailed cost analysis was performed to quantify the impact of key system and financial parameters in the levelized cost of electricity from PV.

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Curran, Alan J. "Lifetime Performance Modeling of Commercial Photovoltaic Power Plants". Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1564763825566542.

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Ng, Annie, i 吳玥. "Polymer blend film for photovoltaic applications optical characterization and solar cell performance". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/196013.

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Sunlight is sustainable, clean and readily available energy source, which is one of the potential alternatives to the traditional energy sources. Recently, the organic photovoltaics (OPVs), in particular polymer solar cells (PSCs), have attracted increasing attention owing to their outstanding properties such as low cost, lightweight, flexible, allowing vacuum-free fabrication process and thin-film architecture. These advantageous material and manufacturing features of PSCs provide the opportunities for many novel applications. However, the lower power conversion efficiencies (PCEs) of PSCs compared to inorganic solar cells hinder their competition in the marketplace. This thesis covers the basic principles of the PSC, strategies for enhancing PCEs as well as the recent development of PSCs. The importance of the source materials has been also demonstrated and discussed. Due to a large number of possibilities, limited resources and time, it is not feasible to do all the work experimentally. Therefore, for continuing advance development of PSCs, the device performance should be modeled as a function of material parameters, which requires the knowledge of material properties, in particular the complex index of refraction N= n - ik. Accurate determination of the optical functions of the active layers and light trapping layers commonly used in PSCs by using the spectroscopic ellipsometry (SE) has been demonstrated. In order to acquire reliable solutions, the methodology including multiple sample analysis, combinations of different measurement techniques, selection of models, the rigorous fitting procedures and the independent verification have been proposed. The obtained information can be used in the simulation to optimize device architectures, model device performance as well as characterize novel materials.
published_or_final_version
Physics
Doctoral
Doctor of Philosophy

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Cuamba, Boaventura Chongo. "Studies of the performance of photovoltaic power plant in a Southern African environment". Thesis, Northumbria University, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245208.

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Baig, Hasan. "Enhancing performance of building integrated concentrating photovoltaic systems". Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/17301.

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Buildings both commercial and residential are the largest consumers of electricity. Integrating Photovoltaic technology in building architecture or Building Integrated Photovoltaics (BIPV) provides an effective means for meeting this huge energy demands and provides an energy hub at the place of its immediate requirement. However, this technology is challenged with problems like low efficiency and high cost. An effective way of improving the solar cell efficiency and reducing the cost of photovoltaic systems is either by reducing solar cell manufacturing cost or illuminating the solar cells with a higher light intensity than is naturally available by the use of optical concentrators which is also known as Concentrating Photovoltaic (CPV) technology. Integrating this technology in the architecture is referred as Building integrated Concentrating Photovoltaics (BICPV). This thesis presents a detailed performance analysis of different designs used as BICPV systems and proposes further advancements necessary for improving the system design and minimizing losses. The systems under study include a Dielectric Asymmetric Compound Parabolic Concentrator (DiACPC) designed for 2.8×, a three-dimensional Cross compound parabolic concentrator (3DCCPC) designed for 3.6× and a Square Elliptical Hyperbolic (SEH) concentrator designed for 6×. A detailed analysis procedure is presented showcasing the optical, electrical, thermal and overall analysis of these systems. A particular issue for CPV technology is the non-uniformity of the incident flux which tends to cause hot spots, current mismatch and reduce the overall efficiency of the system. Emphasis is placed on modelling the effects of non-uniformity while evaluating the performance of these systems. The optical analysis of the concentrators is carried out using ray tracing and finite element methods are employed to determine electrical and thermal performance of the system. Based on the optical analysis, the outgoing flux from the concentrators is predicted for different incident angles for each of the concentrators. A finite element model for the solar cell was developed to evaluate its electrical performance using the outputs obtained from the optical analysis. The model can also be applied for the optimization of the front grid pattern of Si Solar cells. The model is further coupled within the thermal analysis of the system, where the temperature of the solar cell is predicted under operating conditions and used to evaluate the overall performance under steady state conditions. During the analysis of the DiACPC it was found that the maximum cell temperature reached was 349.5 K under an incident solar radiation of 1000 W/m2. Results from the study carried on the 3DCCPC showed that a maximum cell temperature of 332 K is reached under normal incidence, this tends to bring down the overall power production by 14.6%. In the case of the SEH based system a maximum temperature of 319 K was observed on the solar cell surface under normal incidence. An average drop of 11.7% was found making the effective power ratio of the system 3.4. The non-uniformity introduced due to the concentrator profile causes hotspots in the BICPV system. The non-uniformity was found to reduce the efficiency of the solar cell in the range of 0.5-1 % in all the three studies. The overall performance can be improved by addressing losses occurring within different components of the system. It was found that optical losses occurred at the interface region formed due to the encapsulant spillage along the edges of the concentrator. Using a reflective film along the edge of the concentrating element was found to improve the optical efficiency of the system. Case studies highlighting the improvement are presented. A reflective film was attached along the interface region of the concentrator and the encapsulant. In the case of a DiACPC, an increase of 6% could be seen in the overall power production. Similar case study was performed for a 3DCCPC and a maximum of 6.7% was seen in the power output. To further improve the system performance a new design incorporating conjugate reflective-refractive device was evaluated. The device benefits from high optical efficiency due to the reflection and greater acceptance angle due to refraction. Finally, recommendations are made for development of a new generation of designs to be used in BiCPV applications. Efforts are made towards improving the overall performance and reducing the non-uniformity of the concentrated illumination.

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Nakayashiki, Kenta. "Understanding of defect passivation and its effect on multicrystalline silicon solar cell performance". Diss., Atlanta, Ga. : Georgia Institute of Technology, 2007. http://hdl.handle.net/1853/19854.

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Thesis (Ph.D)--Electrical and Computer Engineering, Georgia Institute of Technology, 2008.
Committee Chair: Dr. Ajeet Rohatgi; Committee Member: Dr. Bernard Kippelen; Committee Member: Dr. Gabriel Rincon-Mora; Committee Member: Dr. Miroslav Begovic; Committee Member: Dr. W. Brent Carter.

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Bliss, Martin. "Measurement system for fast power and energy rating of photovoltaic devices". Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8336.

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This thesis presents a new type of solar simulator and new measurement methods that allow for fast power rating of photovoltaic devices and for fast performance measurements for energy rating and energy yield predictions indoors under controlled, and more realistically simulated outdoor conditions. A novel indoor measurement system for photovoltaic device characterisation based on light emitting diodes (LEDs) as the light sources is described. The solar simulator is capable of reproducing spectral changes seen in natural sunlight, with its intricacies of variable air mass and weather conditions, to a better match than previously possible. Furthermore, it allows measurements under varying light intensity and device temperature. The prototype LED-based solar simulator developed is characterised and its measurement quality is analysed. The system achieves a class BAA solar simulator classification with a class B spectral match, class A light intensity uniformity and a class A temporal stability. It is the first system of its kind that meets the standards of a solar simulator in spectral match to the standard sunlight spectrum and in terms of minimum light intensity. An uncertainty analysis shows that calibration uncertainty for crystalline silicon solar cells is 5% in maximum power with a 95.45% level of confidence. Recommendations for further versions of the solar simulator are given and show potential of reducing this uncertainty down to 2.9% across all measurement spectra (1.8% with a primary calibrated reference cell). A new method for automated power-rating of single- and multi-junction devices is developed. The method uses a unique spectral response measurement and fitting method. It eliminates the need of external measurement equipment for determining spectral response. A simulated characterisation of an amorphous silicon single- and double-junction solar cell show accuracy of better than 0.5% in maximum power. First measurements on the LED-based solar simulator show a measurement error of 4.5% in maximum power, which is due to a lack of measurement feedback of spectral output and measurement irradiance. The first three-dimensional performance matrix for use in photovoltaic energy rating is reported, utilising the LED-based solar simulator. Device characteristics are measured indoors under varying irradiance, temperature and spectrum. A measurement method is detailed and utilised on a crystalline and amorphous silicon solar cell. It allows for the first time a direct investigation of spectral effects on photovoltaic devices under controlled conditions. Results show that amorphous silicon devices are very sensitive to changes in spectrum. Thus, spectral effects should not be neglected in energy yield predictions for such devices.

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17

Li, Chu Tu. "Development of Field Scenario Ray Tracing Software for the Analysis of Bifacial Photovoltaic Solar Panel Performance". Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35523.

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This thesis is based on a project "Bifacial Photovoltaic Energy Production Analysis" to build a detailed simulation model system accurately simulate bifacial panel performance under real field radiation conditions and deployment configuration, and to predict its corresponding energy yield. To the author’s up-to-date knowledge, the model system is unpreceded among same type simulation software in complexity, details in consideration, ranges of deployment and parameters. The model system can also be used as a platform for more components and variables to be added on, such as adding on more rows of panel arrays to simulate bifacial solar farm scenario; and adding spectral information for more accurate analysis. The system components’ sub-models were carefully chosen based on a broad literature review in related aspects; especially in sky diffuse radiance, ground reflection, and bifacial solar cells. Built in MATLAB© based on mathematical expressions from above said models, the system consists of 5 bifacial panels and their racking as shading objects and the central panel performance is under investigation and has taken consideration of all possible panel azimuth and elevation combinations. Model simplification and resolution are carefully considered so to achieve a good balance in complexity, computation load and output accuracy. Output reliability is confirmed with other people’s work. Furthermore, the model has been fully checked and peer tested. Outputs under different parameter settings are analysed and discussed. Conclusions and recommended future work are provided at the end of the thesis.

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Mulderig, Andrew J. "Performance and Active Layer Morphology of P3HT-PCPDTBT Organic Photovoltaic Cells". University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1457619609.

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19

Mayer, Jamie Lynn. "Design of a Rooftop Photovoltaic Array for the George C. Gordon Library at Worcester Polytechnic Institute: Structural, Thermal, and Performance Analysis". Digital WPI, 2010. https://digitalcommons.wpi.edu/etd-theses/368.

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In 2009, WPI formed a Presidential Task Force to engage the WPI community in sustainability research, thought, and action. One of the Presidential Task Force's specific objectives is to improve campus environmental performance, which includes energy conservation. Several new buildings such as the Bartlett Center and East Hall have utilized new green building techniques and materials. Older buildings at WPI which were built before new green building techniques and materials were developed can be equipped with photovoltaic systems to reduce the environmental impact and increase clean energy use. This thesis presents a rooftop photovoltaic array design for the George C. Gordon library at WPI which is expected to produce over 27,000 kWh and offset over 56,000 lbs of carbon dioxide emissions annually. The materials science and engineering of the photovoltaic system components are an important part of the design process. Structural and thermal modeling of photovoltaic components during the initial phase of array design is critical to the success of the PV system and maximizing the energy from the system. This thesis presents how differences in photovoltaic materials and mounting systems result in changes in lifetime and reliability. Using common wind, ice, snow and hail loads for the Worcester, MA area ANSYSÃ¢â€žÂ¢ structural simulations show that an attached mounting system is more structurally stable than a ballasted system. Using local weather data and thermal cycling, ANSYSÃ¢â€žÂ¢ thermal simulations show that silicon PV modules outperform other technologies at lower temperatures while cadmium telluride PV modules outperform other technologies at higher temperatures. It is recommended that WPI install poly-silicon PV modules, such as Evergreen Solar PV modules, to maximize power output.

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Leyte-Vidal, Albert. "ESTABLISHING DEGRADATION RATES AND SERVICE LIFETIME OF PHOTOVOLTAIC SYSTEMS". Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3001.

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As fossil fuel sources continue to diminish, oil prices continue to increase, and global warming and CO2 emissions keep impacting the environment, it has been necessary to shift energy consumption and generation to a different path. Solar energy has proven to be one of the most promising sources of renewable energy because it is environmentally friendly, available anywhere in the world, and cost competitive. For photovoltaic (PV) system engineers, designing a PV system is not an easy task. Research demonstrates that different PV technologies behave differently under certain conditions; therefore energy production varies not only with capacity of the system but also with the type of module. For years, researchers have also studied how these different technologies perform for long periods of time, when exposed out in the field. In this study, data collected by the Florida Solar Energy Center for periods of over four years was analyzed using two techniques, widely accepted by researchers and industry, to evaluate the long‐term performance of five systems. The performance ratio analysis normalizes system capacity and enables the comparison of performance between multiple systems. In PVUSA Regression analysis, regression coefficients are calculated which correspond to the effect of irradiance, wind speed, and ambient temperature, and these coefficients are then used to calculate power at a predetermined set of conditions. This study allows manufacturers to address the difficulties found on system lifetime when their modules are installed out on the field. Also allows for the further development and improvement of the different PV technologies already commercially available.
M.S.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering MSEE

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21

Ska-Hiish, Manuel Dave Hokororo. "A performance analysis of planar and radial pn junction based photovoltaic solar cells". Thesis, University of British Columbia, 2013. http://hdl.handle.net/2429/45418.

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In this thesis, the performance of both planar and radial pn junction based photovoltaic solar cells are examined for a broad range of materials. The materials considered include silicon, gallium arsenide, germaniun, indium nitride, and gallium nitride. The photovoltaic solar cell performance model of Kayes et al. [B.M. Kayes, H.A. Atwater, and N.S. Lewis, Journal of Applied Physics, volume 97, pp. 14302-1-11, 2005], is employed for the purposes of this analysis. Three solar cell performance metrics, evaluated using the et al., model are considered in this analysis: (1) the short-circuit current density, (2) the open-circuit voltage, and (3) the efficiency. The results suggest that while planar pn junction based photovoltaic solar cells are sensitive to trapping concentration levels, the radial pn junction based photovoltaic solar cells are relatively insensitive to trapping concentrations. This suggests that in certain cases, such as when there are materials with high concentration of traps, radial pn junction based photovoltaic solar cell offer inherent advantages over their planar counterparts.

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22

Micheli, Leonardo. "Enhancing electrical and heat transfer performance of high-concentrating photovoltaic receivers". Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/18484.

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In a world that is constantly in need of a continuous, reliable and sustainable energy supply, concentrating photovoltaic technologies have the potential to become a cost effective solution for large scale power generation. In this light, important progresses have been made in terms of cell’s design and efficiency, but the concentrating photovoltaic industry sector still struggles to gain market share and to achieve adequate economic returns. The work presented in this thesis is focused on the development of innovative solutions for high concentrating photovoltaics receivers. The design, the fabrication and the characterization of a large cell assembly for high concentrations are described. The assembly is designed to accommodate 144 multijunction cells and is rated to supply energy up to 2.6kWe at 500 suns. The original outline of the conductive copper layer limits the Joule losses to the 0.7% of the global power output, by reducing the number of interconnections. All the challenges and the issues faced in the manufacturing stage are accounted for and the reliability of the fabrication has been proven by quality tests and experimental investigations conducted on the prototype. An indoor characterization shows the receiver’s potential to supply a short-circuit current of 5.77A and an open circuit voltage per cell of 3.08V at 500×, under standard test conditions, only 4.80% and 2.06% respectively lower than those obtained by a commercial single-cell assembly. An electrical efficiency of 29.4% is expected at 500 suns, under standard conditions. A prototype’s cost of $0.91/Wp, in line with the actual price of CPV systems, has been recorded: a cost breakdown is reported and the way to further reduce the cost have been identified and is accounted. In a second approach, the design of a natural convective micro-finned array to be integrated in a single cell receiver has been successfully attempted. Passive cooling systems are usually cheaper, simpler and considered more reliable than active ones. After a detailed review of micro-cooling solutions, an experimental investigation on the thermal behaviour of micro-fins has been conducted and has been combined with a multiphysics software model. A micro-finned heat sink shows the potential to keep the CPV temperature below 100°C under standard conditions and the ability to handle the heat flux when the cell’s efficiency drops to zero. Moreover, a micro-finned heat sink demonstrates the potential to introduce significant benefits in terms of material usage and weight reduction: compared to those commercially available, a micro-finned heat sink has a power-to-weight ratio between 6 and 8 times higher, which results in lower costs and reduced loads for the CPV tracker.

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Mcvey, White Patrick. "A New Characterization Technique to Analyze Concentrator Photovoltaic Optical System Performance". Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35816.

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Concentrator photovoltaics is a promising renewable energy technology, especially for utility or large-scale deployments. Like all new technologies, it has obstacles and setbacks to overcome. More specifically, the optics in a concentrator photovoltaics system introduce non-uniform spatial and spectral illumination on the cell, which can change under different operating conditions. This work was put together to discover a new characterization technique capable of analyzing the performance of a concentrator photovoltaics and provide insight to the field on what is happening within the system, linking modeling results seen in the literature to these experimental outcomes. The thesis is composed of three journal papers written by the candidate, who’s contributions are outlined at the beginning of each chapter. In order to study the illumination profiles on the cells, a new method to characterize the optical components had to be developed. Previous version lacked the ability to control the temperature of the lens and had low spectral resolution of the irradiance profiles. To improve, a novel indoor measurement method was developed capable of spectrally imaging concentrator photovoltaics optics and recreate outdoor operating conditions in a controllable environment. With the calibrated system, our test-bench is capable of measuring the spectral distribution with a 10μm2 resolution and characterizing the output of a system to within 3%. Exploiting this experimental technique, the individual effects of module misalignment, cell to primary distance, and lens temperature was studied for three leading technologies associated with the three generations of concentrator photovoltaics optical architectures. Focusing on Fresnel-based concentrator optics, the performance of silicone on a glass module without a secondary optic is the most sensitive to operating conditions, where lens temperature can decrease the absolute efficiency resulting in a difference of 11% in the annual energy yield. The next two generations have secondary optics but are designed slightly differently. The truncated inverted pyramid, designed independently of the primary optic, favoured higher lens temperature values and there was only a difference of 1% in the energy yield calculation. The primary and secondary optics in the 4-fold Fresnel-Kohler are designed together, due to new development tools, and showed the highest stability under the different operating conditions, demonstrating that concentrator photovoltaics is on the right track to overcoming its onset issue. As the technology matures, future designs can improve on the issues characterized within this thesis.

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Williams, Sheryl R. "Site-specific energy prediction for photovoltaic devices". Thesis, Loughborough University, 2009. https://dspace.lboro.ac.uk/2134/28317.

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This thesis presents an energy prediction tool for photovoltaic (PV) modules, based on the measure-correlate-predict principle. The tool allows quantification of the impact of the different environmental factors influencing PV device efficiency for different sites as they deviate from standardised test conditions and combines their effects for energy yield prediction of different module technologies operating in different climates. Amongst these environmental influences, the impact of angle of incidence has been particularly under-researched. In this work, a systematic investigation of the influence of angle of incidence on PV module performance is realised. This is achieved using both short-term module characterisation and long-term energy yield measurement campaigns. A customised purpose built dual axis tracker for mounting paired sets of modules on a fixed south-facing, 45-degree tilted rack is used to investigate the differences in module performance. The quality and quantity of the composition of the incident irradiance is described for various sky conditions at high latitude locations. Furthermore, an understanding of the entangled effects on photocurrent of both the angle of incidence and spectral variation is presented. This is achieved by analysing data from a system developed especially in this work which integrates an instantaneous all-sky mapping of irradiance from a monochromatic CCD camera with precision measurements of small-aperture normal irradiance from a collimated pyranometer in the short-term measurement campaign. The proposed energy prediction tool is validated using long-term datasets from several locations and is compared to other current methods. This was conducted under the European-funded PV-Catapult and IP Performance projects. The tool's prediction uncertainty falls within the ±5% for crystalline and ±10% for thin films, which is the same accuracy as other methods and within the measurement uncertainty of outdoor measurements.

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OTTOSSON, SIMON. "Case study of Urban Solar Photovoltaic systems Technical and Economical performance in Nordic climates". Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302517.

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The thesis is conducted with Vasakronan for their PV sites. The aim of this thesis is to evaluate the techno-economical effectiveness of urban stationed solar photovoltaic systems in Nordic environments in terms of inverter and module performance. This is made through a case study to compare solar power optimizers and string inverters performances as well as a comparison of crystalline silicon modules to thin film modules performance. Five PV sites situated in Stockholm and Uppsala are evaluated and modeled using the software System Advisor Model to enable a case study with alterations of system congurations. The inverter congurations were tested for two sites. For one of the sites solar power optimizers are shown to be more benecial, improving the protability index by 5 % compared to using string inverters, while string inverters were the more favourable for one site with a 4 % protability index increase. The variation is highly dependent of the amount of surrounding infrastructure. The module congurations are tested for all five of the sites. The thin film modules provided an increased protability index value of 12 % and 15 % each for two of the sites while the silicon modules provided an increase between 5 % to 7 % for three of the sites. The result shows that thin film modules are more advantageous at certain intervals of tilt- and azimuth angles though less competitive for the typical installation presets.
Uppsatsen utförs med Vasakronan på deras PV siter. Målet med uppsatsen är at utvärdera den techno-ekonomiska effektiviteten för stadsplacerade sol- cellessystem i nordiska klimat i form av prestanda av växelriktar- och modul teknologier. Detta utförs genom en fallstudie för att jämföra prestanda dels mellan solar power optimizers och växelriktare samt mellan kristallina- och tunnfilmsmoduler. Fem solcellssiter anlagda i Stockholm och Uppsala undersöks och modelleras i programmet System Advisor Model för att kunna skapa olika systemkongurationer. Växelriktarkongurationerna jämfördes för två siter. För en av siterna var solar power optimizers det mer fördelaktiga valet, det ökade lönsamhetsindex med 5 % mot att använda växelriktare. Medan det på den andra siten var mer fördelaktigt med växelriktare med en ökning av lönsamhetsindex på 4 %. Variationen var beroende av runtomkringliggande infrastruktur. Modulkongurationerna testas för alla fem siter. Tunnfilmsmodulerna gav på två av siterna en lönsamhetsindexökning på 12 % och 15 % var, medan kristallina moduler gav en lönsamhetsindexökning mellan 5 % och 7 % på tre av siterna. Resultaten visar att tunnfilmsmodulerna är mer fördelaktiga för särskilda intervall av lutnings- och azimutvinklar men mindre fördelaktiga för mer konventionella installationsförutsättningar.

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Kurdia, Ali. "Consequences of Nordic Conditions on the Performance of Large-Scale Building Applied PV Installations". Thesis, Högskolan Dalarna, Energiteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:du-26570.

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This thesis aimed for a better understanding of the Nordic weather conditions in terms of snow induced soiling on the performance and production of an established photovoltaic plant located on the roof of Økern nursing home, Oslo. In order to realize the main aim, several steps had to be done in preparation of the main analysis, these steps in fact are as important to this thesis as the main deliverable. The search for appropriate meteorological data proved to be not an easy task because of the scarcity of ground measurement stations, and the high inaccuracies in satellite observations. After analyzing all the sources with available data for the region of Oslo, three sources of data were chosen based on comparisons to an onsite set of reference measurements, these are the Blindern meteo station, the NASA SSE satellite derived observations, and the STRANG data base. A model of the actual system was created in PVsyst, exceptional attention to the level of detail was exercised in order to approach the case of eliminating any source of variation in the simulated models other than the required study parameter, the soiling. Simulations of many system variants ultimately resulted in the aggregation of a soiling loss profile to be used in conjunction with each of the meteo sources to predict the snow induced soiling consequences on the system. The soiling loss profiles were tested and the results compared to actual system production measurements, and it was successful in introducing the correction the model needed to simulate the system closely to reality. However, absolute change in production figures is relatively small, therefore, this study and any future continuation of it is oriented into research and improvement as it possess minimal impact on a commercial application.

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Eeles, Alexander. "Performance characterisation of photovoltaic devices : managing the effects of high capacitance and metastability". Thesis, Loughborough University, 2016. https://dspace.lboro.ac.uk/2134/23254.

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It is essential to make performance measurements of photovoltaics modules in order to quantify the power they will produce under operational conditions. Performance measurements are fundamental throughout the photovoltaic industry, from product development to quality control in manufacturing and installation in the field. Rapid and economic evaluation of photovoltaic performance requires measurements using pulsed illumination solar simulators. However some devices have characteristics which can cause difficulties making these measurements. The aim of this thesis is to overcome these measurement problems focusing particularly on two of the most prevalent and pressing of these problematic characteristics: high capacitance and metastability. A new method for measuring high capacitance modules in a pulsed simulator, based on tailor made voltage ramps, was developed. The voltage ramp is tailor made such that the measurement time is minimised while maintaining high accuracy (0.5 %), allowing the measurement of high capacitance modules in a single 10ms illumination pulse. The necessary inputs for this method are the capacitance and dark current as a function of voltage for each module. In order to make these measurements, at the high forward bias voltages required, a new system was developed. The tailored voltage ramp can be created individually for each module, since the process is rapid an automatic. This makes the method applicable to a production line or to test house measurements. In addition to their use as inputs for the voltage ramp design, the capacitance and dark current also contain other valuable information, including effective minority carrier lifetime. In several thin film technologies, such as CIGS, the efficiency is not a fixed value, rather the module is metastable and the efficiency changes depending on the previous exposure /preconditioning of the device. Preconditioning is normally applied to these devices before measurement in order to put them in a specific state that is repeatable and representative of outdoor operation. Improved preconditioning practices are vital for performance measurements in CIGS modules. Therefore the preconditioning behaviour of a variety of CIGS modules from different manufacturers was investigated. The effect of preconditioning varied for different modules, commonly the fill factor improved substantially, but often changes in open circuit voltage were also seen and in some cases also substantial changes in short circuit current. The rates of preconditioning and relaxation were found to follow stretched exponential behaviour, such that the changes occur linearly on a logarithmic timescale over several orders of magnitude in time. The total time for performance stabilisation was found to vary significantly between different types of module. Because of this stretched exponential behaviour, even though the module took days to fully relax to the dark state, there was significant relaxation within the tens of minutes that it would normally take a module to cool down after light soaking before it could be measured. The major implication of observed kinetics is that in order to achieve repeatable measurement the timing in each element of a preconditioning routine should be controlled such that the fractional error in the duration of each step is small. During the investigation an unexpectedly short timescale preconditioning effect was observed, which occurs on a millisecond timescale and relaxes in seconds. It was shown that the measurement artefacts introduced using this method can be eliminated by using electrical forward bias until immediately before the measurement. Another measurement system was developed to track the dark current and C-V characteristic of the modules during electrical bias preconditioning and subsequent relaxation. These measurements demonstrate that more than one process involved during preconditioning in CIGS. Changes occur both in the doping in the bulk of the absorber and also in charge accumulation occurring near to the absorber / buffer interface. The theoretical models for preconditioning in CIGS were reviewed and compared to the experimental results. A rate model was developed based on the theory of the metastable VSe-VCu defect. This model was shown to correspond well to the rates of preconditioning and relaxation in CIGS. The non-exponential behaviour was shown to be compatible with a distribution of activation energies for the transition between different defect states. The difference in the time taken for modules to stabilise is explained by differences in doping density and the density of VSe-VCu defects. The work presented facilitates more accurate, economical performance measurements for high capacitance devices and CIGS devices, thereby contributing to the large scale implementation of photovoltaics as power source.

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Simon, Michael. "On the evaluation of spectral effects on photovoltaic modules performance parameters and hotspots in solar cells". Thesis, University of Fort Hare, 2009. http://hdl.handle.net/10353/257.

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The performance of photovoltaic (PV) modules in terms of their ability to convert incident photon to electrical energy (efficiency) depends mostly on the spectral distribution of incident radiation from the sun. The incident spectrum finally perceived by the module depends strongly on the composition of the medium in which it has traveled. The composition of the earth’s atmosphere, which includes, amongst others, water vapour, gases such as carbon dioxide and oxygen, absorbs or scatters some of the sunlight. The incident solar spectrum is also modified by the diffuse aspect of radiation from the sky which strongly depends on aerosol concentration, cloudiness and local reflection of the earth’s surface. Although it is well known that the changes in outdoor spectrum affect device performance, little work has been conducted to support this theory. This is probably due to lack of spectral data or in certain instances where data is available, little knowledge of interpreting that data. The outdoor spectral data that one obtains in the field does not come clearly for just simple interpretation. Different analytical interpretation procedures have been proposed, all trying to explain and quantify the spectral influence on PV devices. In this study an assessment methodology for evaluating the effects of outdoor spectra on device performance parameters during the course of the day, seasons and or cloudy cover has been developed. The methodology consists of developing a device dependant concept, Weighted Useful Fraction (WUF) using the outdoor measured spectral data. For measuring PV module’s performance parameters, a current-voltage (I-V) tester was developed in order to monitor the performance of six different module technologies. The Gaussian distribution was used to interpret the data. For hot-spot analysis, different techniques were used, which include Infrared thermographic technique for identifying the hot-spots in the solar cells, SEM and EDX techniques. The AES technique was also used in order to identify other elements at hot-spots sites that could not be detected by the EDX technique. iii Results obtained indicate that multicrystalline modules performance is affected by the changes in the outdoor spectrum during summer or winter seasons. The modules prefer a spectrum characterized by WUF = 0.809 during summer season. This spectrum corresponds to AM 2.19 which is different from AM 1.5 used for device ratings. In winter, the mc-Si module’s WUF (0.7125) peaks at 13h00 at a value corresponding to AM 1.83. Although these devices have a wider wavelength range, they respond differently in real outdoor environment. Results for mono – Si module showed that the device performs best at WUF = 0.6457 which corresponds to AM 1.83 during summer season, while it operates optimally under a winter spectrum indicated by WUF of 0.5691 (AM2.58). The seasonal changes resulted in the shift in WUF during day time corresponding to the “preferred” spectrum. This shift indicates that these devices should be rated using AM values that correspond to the WUF values under which the device operates optimally. For poly-Si, it was also observed the WUF values are lower than the other two crystalline-Si counterparts. The pc-Si was observed to prefer a lower AM value indicated by WUF = 0.5813 during winter season while for summer it prefers a spectrum characterized by WUF = 0.5541 at AM 3.36. The performance of the single junction a-Si module degraded by 67 percent after an initial outdoor exposure of 16 kWh/m² while the HIT module did not exhibit the initial degradation regardless of their similarities in material composition. It was established that the WUF before degradation peaks at 15h00 at a value of 0.7130 corresponding to AM 4.50 while the WUF after degradation “prefers” the spectrum (WUF = 0.6578) experienced at 15h30 corresponding to AM value of 5.57. Comparing the before and after degradation scenarios of a-Si:H, it was observed that the device spends less time under the red spectrum which implies that the device “prefers” a full spectrum to operate optimally. The degradation of a-Si:H device revealed that the device spectral response was also shifted by a 7.7 percent after degradation. A higher percentage difference (61.8 percent) for spectral range for the HIT module is observed, but with no effects on device parameters. Seasonal changes (summer/winter) resulted in the outdoor spectrum of CuInSe2 to vary by WUF = 1.5 percent, which resulted in the decrease in Isc. This was ascertained by iv analyzing the percentage change in WUF and evaluating the corresponding change in Isc. The analysis showed that there was a large percentage difference of the module’s Isc as the outdoor spectrum changed during the course of the day. This confirmed that the 17 percent decrease in Isc was due to a WUF of 1.5 percent. In mc-Si solar cells used in this study, it was found that elemental composition across the entire solar cell was not homogenously distributed resulting in high concentration of transition metals which were detected at hot spot areas. The presence of transition metals causes hot-spot formation in crystalline solar cells. Although several transition elements exist at hot-spot regions, the presence of oxygen, carbon, iron and platinum was detected in high concentrations. From this study, it is highly recommended that transition elements and oxygen must be minimized so as to increase the life expectancy of these devices and improve overall systems reliability

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Wang, Feijiu. "Studies of nano-carbon hole transport layer for high performance photovoltaic devices". Kyoto University, 2016. http://hdl.handle.net/2433/215655.

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Dasari, Mallika. "DESIGN, SYNTHESIS, AND CHARACTERIZATION OF NANOCOMPOSITES TO IMPROVE THE PERFORMANCE OF PHOTOVOLTAIC CELLS". OpenSIUC, 2016. https://opensiuc.lib.siu.edu/dissertations/1276.

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My PhD thesis work is to design, synthesize, and characterize inexpensive and reliable nanocomposites for the photovoltaic (PV) devices. Photovoltaic materials utilized in our studies were synthesized using simple and inexpensive methods. The material properties were tailored and optimized to improve the optical absorption and charge transport properties. The PV cells fabricated with these materials exhibited improved power conversion efficiencies (PCE). The origin of charge generation and charge transfer was studied using different photoactive materials such as CdSe quantum dots (QDs), perylene-3, 4, 9, 10-tetracarboxylic-3, 4, 9, 10-dianhydride (PTCDA), poly(3-hexylthiophene) (P3HT), multiwalled carbon nanotubes (MWCNTs), multilayer graphene (MuLG), and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM).

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Nobre, AndrÃ© Maia. "Short-term solar irradiance forecasting and photovoltaic systems performance in a tropical climate in Singapore". reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/162682.

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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro TecnolÃ³gico, Programa de PÃ³s-GraduaÃ§Ã£o em Engenharia Civil, FlorianÃ³polis, 2015.
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A humanidade usou e continua consumindo em grande quantidade os recursos nÃ£o-renovÃ¡veis do planeta como petrÃ³leo, gÃ¡s natural e carvÃ£o mineral para suprir suas necessidades energÃ©ticas. Somente nas Ãºltimas duas dÃ©cadas que outras fontes de energia renovÃ¡veis, como a solar fotovoltaica e a eÃ³lica, passaram a se tornar relevantes na geraÃ§Ã£o de energia elÃ©trica em nÃvel mundial. InstalaÃ§Ãµes de sistemas fotovoltaicos ao redor do mundo atingiram crescimento da ordem de 40% durante os Ãºltimos quinze anos. Entretanto, a grande maioria destes sistemas, (acima de 90%), estÃ£o localizados em regiÃµes onde o recurso solar nÃ£o Ã© tÃ£o abundante, ou seja, fora da regiÃ£o dos trÃ³picos do planeta. Devido a este fato, ao tentar incorporar a energia solar fotovoltaica Ã s redes elÃ©tricas, uma pergunta que sempre surge estÃ¡ relacionada a variaÃ§Ã£o desta forma de geraÃ§Ã£o de energia elÃ©trica com a produÃ§Ã£o alternante durante o dia devido ao movimento das nuvens e total ausÃªncia no perÃodo noturno. Mesmo assim, em alguns paÃses, jÃ¡ se atinge percentuais em torno de 5 a 10% de contribuiÃ§Ã£o da energia elÃ©trica proveniente de energia solar fotovoltaica. Passa a ser desafiador a inserÃ§Ã£o dessa fonte de energia Ã rede, de maneira intensiva, em paralelo com os recursos jÃ¡ existentes (em sua maioria ainda de origem fÃ³ssil). Nesta tese, foi avaliada a previsÃ£o do recurso solar em curtÃssimo prazo (como 15-min, 30-min e uma hora) para uma regiÃ£o tropical do planeta, neste caso em Cingapura, ilha que se localiza prÃ³xima Ã linha do equador, no Sudeste AsiÃ¡tico. Esta tese foca em mÃ©todos existentes de previsÃ£o de irradiÃ¢ncia, mas tambÃ©m explora uma nova proposta hÃbrida, adaptada a uma localidade tropical. AlÃ©m das previsÃµes de irradiaÃ§Ã£o solar, simulaÃ§Ãµes de sistemas fotovoltaicos e o cÃ¡lculo de seu desempenho foram estudados e avaliados de modo a se prever quanto de energia elÃ©trica Ã© produzida com a mesma antecedÃªncia dada nos produtos de previsÃ£o do recurso solar. A influÃªncia da gaze de queimada foi um fenÃ´meno particular, comum na Cingapura de hoje, que afeta o desempenho de sistemas fotovoltaicos e que foi investigado em detalhe. Todo o trabalho foi validado por redes detalhadas de estaÃ§Ãµes meteorolÃ³gicas em solo e tambÃ©m atravÃ©s de monitoramento de sistemas fotovoltaicos por toda Cingapura.

Abstract : Humanity has used and continues to consume in great proportion non-renewable energy resources of the planet such as oil, natural gas and coal in order to fulfil its energy needs. It was only during the past two decades that other sources of renewable energy such as solar photovoltaics (PV) and wind energy became somewhat relevant towards electricity generation in the world. PV installations worldwide have reached a compound annual growth rate of ~40% for the last fifteen years. However, the great majority of these systems (over 90% of them) are located where the solar energy resource is not the most abundant - outside of the tropical regions of the planet. While trying to incorporate solar energy PV into electrical power grids, one common question which arises is related to the variable aspect of this form of energy generation - with alternating production during the day due to cloud motion, and total absence during night time. Nonetheless, in some countries, contribution ratios of 5 to 10% of electrical energy from solar PV have been achieved. It becomes then challenging to integrate this source of energy into grids in a professional way, in parallel with existing resources (mostly still fossil-fuel-based). In this thesis, short-term forecasting (for time horizons such as 15-min, 30-min and 1-hour) of the solar resource was investigated in a tropical region of the world - in Singapore, 1Â° North of the Equator, in Southeast Asia. This thesis focuses on existing methods for irradiance forecasting, but also explores a novel Hybrid proposal, tailored to the tropical environment at hand. Beyond the forecast of the solar energy irradiance ahead of time, PV system simulation and performance assessment were studied and evaluated with the goal of predicting how much electricity is produced in the same time frame given by the solar irradiance forecasting products. The influence of haze was a particular phenomenon, common in today?s Singapore, which affects PV system performance and which was investigated in detail. All work has been validated by a comprehensive network of ground-based meteorological stations, as well as by various PV system monitoring sites throughout Singapore.

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Nobre, André Maia. "Short-term solar irradiance forecasting and photovoltaic systems performance in a tropical climate in Singapore". reponame:Repositório Institucional da UFSC, 2015. https://repositorio.ufsc.br/xmlui/handle/123456789/169480.

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Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Civil, Florianópolis, 2015.
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A humanidade usou e continua consumindo em grande quantidade os recursos não-renováveis do planeta como petróleo, gás natural e carvão mineral para suprir suas necessidades energéticas. Somente nas últimas duas décadas que outras fontes de energia renováveis, como a solar fotovoltaica e a eólica, passaram a se tornar relevantes na geração de energia elétrica em nível mundial. Instalações de sistemas fotovoltaicos ao redor do mundo atingiram crescimento da ordem de 40% durante os últimos quinze anos. Entretanto, a grande maioria destes sistemas, (acima de 90%), estão localizados em regiões onde o recurso solar não é tão abundante, ou seja, fora da região dos trópicos do planeta. Devido a este fato, ao tentar incorporar a energia solar fotovoltaica às redes elétricas, uma pergunta que sempre surge está relacionada a variação desta forma de geração de energia elétrica com a produção alternante durante o dia devido ao movimento das nuvens e total ausência no período noturno. Mesmo assim, em alguns países, já se atinge percentuais em torno de 5 a 10% de contribuição da energia elétrica proveniente de energia solar fotovoltaica. Passa a ser desafiador a inserção dessa fonte de energia à rede, de maneira intensiva, em paralelo com os recursos já existentes (em sua maioria ainda de origem fóssil). Nesta tese, foi avaliada a previsão do recurso solar em curtíssimo prazo (como 15-min, 30-min e uma hora) para uma região tropical do planeta, neste caso em Cingapura, ilha que se localiza próxima à linha do equador, no Sudeste Asiático. Esta tese foca em métodos existentes de previsão de irradiância, mas também explora uma nova proposta híbrida, adaptada a uma localidade tropical. Além das previsões de irradiação solar, simulações de sistemas fotovoltaicos e o cálculo de seu desempenho foram estudados e avaliados de modo a se prever quanto de energia elétrica é produzida com a mesma antecedência dada nos produtos de previsão do recurso solar. A influência da gaze de queimada foi um fenômeno particular, comum na Cingapura de hoje, que afeta o desempenho de sistemas fotovoltaicos e que foi investigado em detalhe. Todo o trabalho foi validado por redes detalhadas de estações meteorológicas em solo e também através de monitoramento de sistemas fotovoltaicos por toda Cingapura.

Abstract : Humanity has used and continues to consume in great proportion non-renewable energy resources of the planet such as oil, natural gas and coal in order to fulfil its energy needs. It was only during the past two decades that other sources of renewable energy such as solar photovoltaics (PV) and wind energy became somewhat relevant towards electricity generation in the world. PV installations worldwide have reached a compound annual growth rate of ~40% for the last fifteen years. However, the great majority of these systems (over 90% of them) are located where the solar energy resource is not the most abundant - outside of the tropical regions of the planet. While trying to incorporate solar energy PV into electrical power grids, one common question which arises is related to the variable aspect of this form of energy generation - with alternating production during the day due to cloud motion, and total absence during night time. Nonetheless, in some countries, contribution ratios of 5 to 10% of electrical energy from solar PV have been achieved. It becomes then challenging to integrate this source of energy into grids in a professional way, in parallel with existing resources (mostly still fossil-fuel-based). In this thesis, short-term forecasting (for time horizons such as 15-min, 30-min and 1-hour) of the solar resource was investigated in a tropical region of the world - in Singapore, 1° North of the Equator, in Southeast Asia. This thesis focuses on existing methods for irradiance forecasting, but also explores a novel Hybrid proposal, tailored to the tropical environment at hand. Beyond the forecast of the solar energy irradiance ahead of time, PV system simulation and performance assessment were studied and evaluated with the goal of predicting how much electricity is produced in the same time frame given by the solar irradiance forecasting products. The influence of haze was a particular phenomenon, common in today?s Singapore, which affects PV system performance and which was investigated in detail. All work has been validated by a comprehensive network of ground-based meteorological stations, as well as by various PV system monitoring sites throughout Singapore.

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Wu, Zhenghui. "Impact of metal oxide/bulk-heterojunction interface on performance of organic solar cells". HKBU Institutional Repository, 2015. https://repository.hkbu.edu.hk/etd_oa/159.

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Organic photovoltaics have shown much promise as an alternative photovoltaic technology for application in low-cost, large-scale and flexible solar cells. The application of metal oxides in organic solar cells (OSCs) and the impact of the properties of metal oxide/organic hetero-interfaces on cell performance have attracted a lot of attention. The metal oxide/organic interfaces have a crucial impact on interfacial charge transfer, charge collection and the overall device performance. This thesis is aimed at clarifying the principal interfacial phenomena occurring at the metal oxide/organic hetero-interfaces as well as effective engineering of those interfacial properties in OSCs. Photo-generated electrons and holes undergo different recombination processes, e.g., bimolecular recombination and trap-assisted recombination, before being collected by the electrodes in OSCs. Light intensity-dependent current densityvoltage (JV) characteristics of OSCs were analyzed to study the effect of recombination on charge collection efficiency. Effect of metal oxide/organic hetero-interfaces on charge transfers at organic/electrode interface was analyzed using transient photocurrent (TPC) measurements. Light intensity-dependent JV characteristics and TPC characteristics were applied to explore the charge recombination dynamics in OSCs with a metal oxide interlayer. This project concentrated on an in-depth investigation of the physics and the interface phenomena such as interfacial exciton dissociation, charge recombination processes, charge collection and interface engineering for high performing OSCs. The fundamentals about light intensity-dependent J-V characteristics for OSCs were summarized. The relationship between the charge recombination dynamics and light intensity-dependent J-V characteristics in OSCs were developed. Light intensity-dependent JSC, VOC and FF in OSCs made with different bulk-heterojunction (BHJ) systems of PTB7:PC70BM, PTB7-Th:PC70BM and PNB4:PC70BM were investigated. It is found that bimolecular recombination is the most prominent factor limiting the performance of OSCs. For freshly made OSCs fabricated based on the commercial polymers, e.g. PTB7 & PTB7-Th, and the new polymer PNB4 synthesized in-house, the trap-assisted charge recombination process in the BHJ active layer plays a relatively small role. This suggests that reducing the bimolecular recombination in OSCs through selecting proper materials and device structures is crucial for enhancing the power conversion efficiency (PCE) of OCSs. In this work, device structures which enable reducing bimolecular recombination in OSCs were investigated. The effect of ZnO interlayer at the interface between BHJ and Al cathode on the performance of PTB7:PC71BM based OSCs was studied by a combination of theoretical simulation and experimental characterization techniques, e.g., using light intensity-dependent JV characteristic and TPC measurements etc. It shows that ZnO interlayer has a profound effect on the performance of the PTB7:PC70BM-based OSCs, although it does not have a significant influence on the maximum absorptance in the active layer. The origin of the improvement in the cell performance is associated with the efficient charge collection due to the favorable exciton dissociation at the electrode/active layer interface. It is shown that the presence of the ZnO interlayer allows using a thinner active layer without moderating the absorption in the optically optimized control OSCs without the ZnO interlayer. OSCs with a ~10 nm thick ZnO interlayer are found to be favorable for the efficient charge collection, and thereby improving the cell performance. The TPC measurements also reveal that the dissociation of excitons at the metal/organic interface of regular OSCs hinders the electron collection. The unfavorable interfacial exciton dissociation can be removed by interposing a ZnO interlayer at the Al/organic interface, thus bimolecular recombination at the electrode/active layer interface can be reduced for improving the charge collection efficiency. PCE of the OSCs using ZnO interlayer was 6.5%, which is about 20% higher than a control cell (5.4%), having an identical device configuration without a ZnO interlayer. Solution-processed anode interlayer, a mixture of solution-processed MoOX and PEDOT:PSS, was adopted for application in inverted PTB7:PC71BM-based OSCs. The ratio of MoOX to PEDOT:PSS in the mixed solution was optimized for achieving the best cell performance. A PCE of 7.4% was obtained for OSCs with an optimal MoOX-PEDOT:PSS based interlayer, interposed between the BHJ active layer and Ag anode, which means 10% enhancement over the PCE of control cell made with an evaporated MoOX interlayer. Light intensity-dependent JV characteristics implied that the bimolecular recombination in OSCs with a MoOX-PEDOT:PSS interlayer was reduced. TPC measurements showed that the favorable exciton dissociation occurs at the organic/MoOX interface for the inverted OSCs. The favorable interfacial exciton dissociation generates an electrical field within a very small space near the interface, contributing significant additional photocurrent when the effective bias across the active layer in the OSCs is low, and thereby assisting in an efficient charge collection at the organic/electrode interface. In addition to the improvement in the cell performance, the solution-processed MoOX-PEDOT:PSS interlayer does not require a post-annealing treatment, which is beneficial for application in solution-processed tandem and flexible OSCs.

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Leighton, Michael. "An Evaluation of The Performance and Comparative Cost of Ground-mounted and Rooftop Mounted Solar Photovoltaic Systems". Master's thesis, Faculty of Engineering and the Built Environment, 2021. http://hdl.handle.net/11427/32770.

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In South Africa, there is an increasing interest in installing rooftop mounted solar photovoltaic systems. However, financing the photovoltaic systems causes most interest to be abandoned, largely due to the cost required to replace a building's asbestos roof. An alternative solution to replacing an asbestos roof is to install a ground-mounted photovoltaic system, which is more costly compared to a rooftop mounted system. This study aims to determine if a ground-mounted or a rooftop mounted solar photovoltaic system is the most financially feasible solar photovoltaic configuration. In this study three photovoltaic systems were analysed, all of which are installed in Atlantis, Western Cape (WC). Since all three systems are in the same area, they are all exposed to the same metrological conditions, allowing for identical energy generation potential. Two of the photovoltaic systems are ground-mounted systems located respectfully at the South African Renewable Energy Incubator (SAREBI) and at Stripform Packaging. The third system is a rooftop mounted system located at SA Tyre Recyclers. The photovoltaic system at SAREBI is a 9.75 kWp system consisting of 30 Canadian Solar CS6U-325P modules, one Schneider Electric 20 kW inverter, a tilt angle of 15° and an azimuth angle of -19°. The photovoltaic system at SA Tyre Recyclers is a 231 kWp system consisting of 700 JA Solar JAP72S-01-330-SC modules, 7 SolarEdge 27.6 kW inverters, a tilt angle of 13° and an azimuth angle of 22°. The photovoltaic system at Stripform Packaging is a 20.1 kWp system consisting of 60 Canadian Solar CS6U-335P modules, one SMA 20 kW inverter, a tilt angle of 15° and an azimuth angle of 46°. To achieve the aim of this study, the performance of each of the solar photovoltaic systems was examined, by comparing their annual specific yield. After which the technical aspects and differences of each of the photovoltaic systems were explored, to illustrate how each of the systems differ technically and how each system can be improved. Finally, the comparative cost of each of the solar photovoltaic systems was examined by analysing the levelized cost of energy (LCOE) and the payback period for each of the photovoltaic systems. The results demonstrated that from an annual specific yield perspective, the ground-mounted configuration was the best performing, whilst from a financial perspective, the rooftop mounted configuration had the lowest levelized cost of energy (LCOE) and payback period. However, installing a ground-mounted system is more financially feasible than replacing an asbestos roof and then installing a rooftop mounted system. In conclusion, by fully understanding the performance, payback period and levelized cost of energy, a clear understanding of potential risk can be determined, thus making the installation of photovoltaic systems more appealing for financiers. It is recommended that this study be repeated in a manner in which each of the photovoltaic system configurations are constructed consisting of all the same photovoltaic components, measuring equipment, tilt and azimuth angles. All of which would result in two identical photovoltaic systems where one is installed on a rooftop and the other installed on the ground. Once the two photovoltaic system configurations are equal in all aspects, an accurate comparison to determine which configuration is the most optimal performer and which is the most financially viable will be possible.

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Yandt, Mark. "Characterization Techniques and Optimization Principles for Multi-Junction Solar Cells and Maximum Long Term Performance of CPV Systems". Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/35870.

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Two related bodies of work are presented, both of which aim to further the rapid development of next generation concentrating photovoltaic systems using high efficiency multi junction solar cells. They are complementary since the characterization of commercial devices and the systematic application of design principles for future designs must progress in parallel in order to accelerate iterative improvements. First addressed, is the field characterization of state of the art concentrating photovoltaic systems. Performance modeling and root cause analysis of deviations from the modeling results are critical for bringing reliable high value products to the market. Two complementary tools are presented that facilitate acceleration of the development cycle. The “Dynamic real-time I V Curve Measurement System…” provides a live picture of the current-voltage characteristics of a CPV module. This provides the user with an intuitive understanding of how module performance responds under perturbation. The “Shutter technique for noninvasive individual cell characterization in sealed concentrating photovoltaic modules,” allows the user to probe individual cell characteristics within a sealed module. This facilitates non-invasive characterization of modules that are in situ. Together, these tools were used to diagnose the wide spread failure of epoxy connections between the carrier and the emitter of bypass diodes installed in sealed commercial modules. Next, the optimization principals that are used to choose energy yield maximizing bandgap combinations for multi-junction solar cells are investigated. It is well understood that, due to differences in the solar resource in different geographical locations, this is fundamentally a local optimization problem. However, until now, a robust methodology for determining the influences of geography and atmospheric content on the ideal design point has not been developed. This analysis is presented and the influence of changing environment on the representative spectra that are used to optimize bandgap combinations is demonstrated. Calculations are confirmed with ground measurements in Ottawa, Canada and the global trends are refined for this particular location. Further, as cell designers begin to take advantage of more flexible manufacturing processes, it is critical to know if and how optimization criteria must change for solar cells with more junctions. This analysis is expanded to account for the differences between cells with up to 8 subcell bandgaps. A number of software tools were also developed for the Sunlab during this work. A multi-junction solar cell model calibration tool was developed to determine the parameters that describe each subcell. The tool fits a two diode model to temperature dependent measurements of each subcell and provides the fitting parameters so that the performance of multi-junction solar cells composed of those subcells can be modeled for real world conditions before they are put on-sun. A multi-junction bandgap optimization tool was developed to more quickly and robustly determine the ideal bandgap combinations for a set of input spectra. The optimization process outputs the current results during iteration so that they may be visualized. Finally, software tools that compute annual energy yield for input multi-junction cell parameters were developed. Both a brute force tool that computes energy harvested at each time step, and an accelerated tool that first bins time steps into discrete bins were developed. These tools will continue to be used by members of the Sunlab.

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Compadre, Senar David. "Performance evaluation of a rooftop solar photovoltaic power plant in the Gävle Arenaby (Gävle, Sweden): Installation testing". Thesis, Högskolan i Gävle, Energisystem, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-26931.

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The current energy situation is taking a turn towards renewable energies, due to the new pacts to curb global warming. These agreements, together with governmental aid, are facilitating an escalation in the production and improvement of new energy systems and the price decrease due to a larger-scale production. Within these energy alternatives, solar energy is found, specifically the subject to be treated in this project is photovoltaic energy, due to its exponential growth in the last 10 years, new tools are being developed for its monitoring and modelling. Therefore, the main objective of this thesis is to develop a method for installation testing of a PV-system. The method should give the installed nominal power of the system and show if the maximum power point trackers work as expected. A large PV-system was installed on the roof of Gävle Arenaby during 2017. A measurement system for monitoring of the power of the system and of the solar irradiance was installed. Different parameters have been taken into account for the adjustment of the model that vary the performance of the system. These factors are: the irradiance received, the module temperature and the angle of incidence. It has been concluded that the results obtained indicate a correct adjustment of the theoretical power against the real power, which means, a correct operation of the generated model. Besides, the expected power follows a linear trend, reaching the power set by the manufacturer for Standard Test Conditions. The results show that the monitored modules-strings fulffill the promised performance and the method for installation testing work as expected. The linear correlation between corrected power and irradiance means that the maximum power point tracker in the inverter works independent of the power.

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Weiss, Lucas. "Modeling of a photovoltaic module under environmental conditions and optimisation of its performance". Thesis, Lyon, INSA, 2015. http://www.theses.fr/2015ISAL0059.

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Dans un contexte de réduction des émissions de gaz à effet de serre et de raréfaction des ressources fossiles et fissiles, l'énergie solaire est l'une des sources d'énergie les plus prometteuses. La quantité d'énergie renouvelable dans le futur paysage énergétique dépend de sa disponibilité, de son coût et de son niveau d'efficacité. Plusieurs enjeux limitent actuellement le développement de l'énergie solaire. Parmi eux, l'élévation de la température des cellules induit une dégradation du productible d'environ 12% dans le cas général. En dépit de ce constat, la structure actuel des modules PV n'a pas variée depuis sa création dans les années 70. L'objectif de cette thèse est d'évaluer les facteurs d’impact qui gouverne l'élévation de la température du module PV en vue d’identifier les moyens de la réduire de manière significative. Un modèle multi-physique est construit pour prédire le comportement du module dans les conditions environnementales de production. Le modèle thermique est basé sur la radiation en milieu semi-transparent. Cette caractéristique conduit à déterminer les équations généralisées de Fresnel pour les milieux absorbants. Cela nous autorise à déterminer la caractéristique spectrale et angulaire de l’émissivité du verre. Le modèle de couplage optique-thermique-électrique est comparé aux mesures en conditions réelles et est capable de prédire le comportement du module sur une période de vingt-quatre heures. Le modèle est en mesure d’évaluer le gain obtenu en optimisant les composants du module. Une étude paramétrique identifie enfin les différentes améliorations permettant d’obtenir une réduction de la température de fonctionnement des modules PV. Cette thèse inclut un état de l'art (chapitre 1), une étude du transfert de chaleur radiative à l'échelle du module PV (chapitre 2), la description détaillée du modèle multiphysique (chapitre 3), l'étude du module PV au travers de la modélisation (chapitre 4), une étude paramétrique (chapitre 5) et une conclusion (chapitre 6)
In the context of greenhouse gas emissions and fossil and fissile resources depletion, solar energy is one of the most promising sources of power. The amount of renewable energies in the future energy mix depends on their availability, on their cost and on their level of efficiency. Various issues still limit the development of the solar energy. Among them, the temperature elevation into the module induces an efficiency degradation of 12% in standard cases. In spite of this statement, the actual solar module structure has not changed since its creation in the seventies, and the technologies are still evaluated at room temperature. The objective of this thesis is to study the impact factors which govern the module temperature elevation in order to identify ways to apply a significant reduction. A multi-physics modeling is built in order to predict the module behavior depending on the environmental conditions. The thermal modeling is grounded on the radiation into participating media. This feature leads to the determination of generalized Fresnel equation for absorbing media. It allows us to determine a spectral and hemispherical value of the glass emissivity. The optical-electrical-thermal modeling has been compared to measurement in real conditions and is able to predict the module behavior over a one-day period. It allows the evaluation of the gain obtained by optimizing the module components. A parametrical study identifies several improvements to lower the module operating temperature. The PhD work includes a state-of-the-art study (chapter 1), a study of the radiation heat transfer at PV module scale (chapter 2), the details of the multiphysics modeling (chapter 3), the study of the PV module through the modeling (chapter 4), a parametrical study (chapter 5) and a conclusion (chapter 6)

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Zarmai, Musa Tanko. "Modelling of solder interconnection's performance in photovoltaic modules for reliability prediction". Thesis, University of Wolverhampton, 2016. http://hdl.handle.net/2436/617782.

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Standard crystalline silicon photovoltaic (PV) modules are designed to continuously convert solar energy into electricity for 25 years. However, the continual generation of electricity by the PV modules throughout their designed service life has been a concern. The key challenge has been the untimely fatigue failure of solder interconnections of solar cells in the modules due to accelerated thermo-mechanical degradation. The goal of this research is to provide adequate information for proper design of solar cell solder joint against fatigue failure through the study of cyclic thermo-mechanical stresses and strains in the joint. This is carried-out through finite element analysis (FEA) using ANSYS software to develop the solar cell assembly geometric models followed by simulations. Appropriate material constitutive model for solder alloy is employed to predict number of cycles to failure of solder joint, hence predicting its fatigue life. The results obtained from this study indicate that intermetallic compound thickness (TIMC); solder joint thickness (TSJ) and width (WSJ) have significant impacts on fatigue life of solder joint. The impacts of TIMC and TSJ are such that as the thicknesses increases solder joint fatigue life decreases. Conversely, as solder joint width (WSJ) increases, fatigue life increases. Furthermore, optimization of the joint is carried-out towards thermo-mechanical reliability improvement. Analysis of results shows the design with optimal parameter setting to be: TIMC -2.5μm, TSJ -20μm and WSJ -1000μm. In addition, the optimized model has 16,264 cycles to failure which is 18.82% more than the expected 13,688 cycles to failure of a PV module designed to last for 25 years.

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Horn, Benjamin. "Maximizing performance: Determining the relative influence of key design elements on the performance grid connected solar photovoltaic systems in Geraldton, Western Australia". Thesis, Horn, Benjamin (2011) Maximizing performance: Determining the relative influence of key design elements on the performance grid connected solar photovoltaic systems in Geraldton, Western Australia. Masters by Coursework thesis, Murdoch University, 2011. https://researchrepository.murdoch.edu.au/id/eprint/7602/.

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This paper investigates data collected from 17 recently installed grid connected solar PV systems in the town of Geraldton, Western Australia with the intention of determining the relative effects on performance of key design criteria. The influence of tilt, orientation, inverter efficiency, module efficiency and the sizing of the inverter are compared statistically to the performance of the systems over a three month period. The conclusion drawn from the data is that the most significant design elements are the tilt of the array and the orientation of the array and that shading can have significant effects on system output.

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Barich, William J., Brent L. Dessing i Antonio B. Harley. "A case analysis of energy savings performance contract projects and photovoltaic energy at Fort Bliss, El Paso, Texas". Thesis, Monterey, California. Naval Postgraduate School, 2006. http://hdl.handle.net/10945/9676.

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MBA Professional Report
The purpose of this MBA Project is to review existing policy of the Federal Energy Management Program under the purview of National Renewal Energy Laboratory (NREL) for Energy Savings Performance Contracts (ESPCs). This project will assess the ability for the Department of Defense to incorporate emerging technologies in alternative energy to supplement or replace existing power sources for DoD installations within the current Energy Savings Performance Contract policy. To do this the project will review previous and existing Energy Savings Performance Contracts. Further, this project will conduct a cost-benefit analysis of conventional power versus emerging photovoltaic energy for the Army’s Fort Bliss in El Paso, TX. The project will also analyze energy demands based on a new force alignment at Fort Bliss in accordance with the recent Base Realignment and Closure (BRAC) findings. The project will review current Energy Performance Contract Policy and recommend changes to allow for the use of emerging alternative energy technologies.

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Fontenele, Luiz Fernando Almeida. "Avaliação de configurações de sistemas fotovoltaicos na região Nordeste do Brasil". Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/106/106131/tde-14122018-185201/.

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Neste trabalho, são avaliadas diferentes configurações de sistemas fotovoltaicos, levando em consideração os principais tipos de módulos fotovoltaicos comercialmente disponíveis e estruturas de suporte. A comparação é delimitada na região Nordeste do Brasil e é baseada, fundamentalmente, em termos de fator de capacidade. Para uma melhor compreensão dos resultados, são mostradas, previamente, as influências que as variáveis meteorológicas exercem na saída do sistema, bem como os efeitos do fator de dimensionamento do inversor (FDI) e do índice de cobertura do terreno (ICT). Os resultados das simulações computacionais realizadas são apresentados em forma de mapas, nos quais é possível verificar as áreas em que os sistemas fotovoltaicos tendem a gerar mais energia elétrica. Entre as configurações estudadas, os maiores valores foram observados para sistemas que utilizam módulos genéricos de filmes finos montados em rastreadores solares de um eixo horizontal, chegando a 36 % de fator de capacidade (em corrente alternada) em algumas regiões do Ceará, Rio Grande do Norte, Paraíba, Pernambuco e Bahia. Além disso, foram evidenciados os ganhos obtidos nos fatores de capacidade ao substituir as estruturas fixas por rastreadores solares. Para um ICT de 0,4, os sistemas que realizam o seguimento, ainda que em um eixo do movimento aparente do Sol, apresentaram ganhos de 18 % a 28 % na energia elétrica anual gerada.
In this work, different configurations of photovoltaic systems are evaluated, considering the main type of commercially available photovoltaic modules and mounting structures. The comparison is delimited to the Northeastern region of Brazil and is based, fundamentally, in terms of capacity factor. The influence on the output of the system of meteorological variables, the inverter loading ratio (ILR 1/FDI) and ground coverage ratio (GCR ICT) are shown in advance for a better understanding of the results. Computational simulations results are presented in maps, in which it is possible to verify the areas where photovoltaic systems tend to generate more electricity. Among the studied configurations, the largest values were observed for systems that use generic thin film modules mounted on one axis horizontal solar trackers, reaching 36 % of capacity factor (in alternating current) in some regions of Ceará, Rio Grande do Norte, Paraíba, Pernambuco and Bahia. Additionally, the gains obtained in the capacity factors when replacing fixed structures by solar trackers were shown. For an GCR of 0.4, systems that track, even on one axis, the apparent motion of the Sun showed gains of 18 % to 28 % on annual generated electricity.

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Ebrahim, Mila. "Performance Evaluation of a Photovoltaic/Thermal (PVT) Collector with Numerical Modelling". Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-302122.

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In Photovoltaic/Thermal (PVT) technology, both PV and solar thermal technology are integrated in the same module for simultaneous electricity and heat production. Research has shown that there are multiple benefits from integrating PVT collectors with a ground source heat pump (GSHP) system, since it allows for seasonal storage of thermal energy over the year. Furthermore, it leads to reduced operating temperatures for the PVT collectors which can increase efficiency and lifetime. The aim of this study is to present the electric and thermal performance of a PVT collector developed by Solhybrid i Småland AB, for different environmental and fluid inlet conditions that can occur when PVT collectors are connected to a GSHP system. Furthermore, the performance of this PVT design is evaluated with ASHRAE (Standard 93-2003), to allow for comparison with other PVT collector designs, with values on the overall heat loss coefficient (UL) and heat removal factor (FR). The modelling tool used for the study is the software COMSOL Multiphysics, which uses the finite element method to solve the partial differential equations in heat transfer and fluid flow problems. Based on the performance curves, the thermal and electrical efficiency of the collector is approximately 48.0-53.4% and 19.0-19.2% respectively at a reduced temperature of zero and irradiance levels of 800-1000 W/m2 for the mass flow rate of 0.026 kg/sm2 which was determined as most suitable to increase thermal performance. Furthermore, these results resulted in a heat removal factor (FR) and overall heat loss coefficient (UL) of 0.56-0.62 and 53.4-53.5 W/m2 K respectively. The results on the performance of the PVT collector in different weather conditions shows that the inlet water temperature can significantly affect operating time and the amount of thermal energy that can be extracted during the year, especially if the collector operates in a colder climate like Sweden. To assess the accuracy of the created model, future work includes experimental testing of the studied PVT collector.
En panel med kombinerad teknik av både solceller och termisk solfångare (PVT) kan producera både elektricitet och värme samtidigt. Forskning har visat att det kan finnas flera fördelar med att integrera PVT-paneler med ett bergvärmesystem, eftersom det mjliggör lagring av termisk energi över året. Dessutom leder ett sådant system till lägre drifttemperaturer som kan öka PVT-panelens effektivitet och livslängd. Syftet med studien är att presentera den elektriska och termiska prestandan av en PVT-panel utvecklat av Solhybrid i Småland AB för olika driftförhållanden som kan uppstå på grund av olika väderförhållanden och inlopps-temperaturer när panelerna är kopplade till ett bergvärmesystem. Vidare utvärderas prestandan för denna panel med ASHRAEmetoden (standard 93-2003), för att möjliggöra jämförelse med andra PVT-paneler. Modelleringsverktyget som använts i studien är mjukvaran COMSOL Multiphysics, som använder finita elementmetoden för att lösa partiella differentialekvationer i värmeöverförings-och flödesproblem. Baserat på prestandakurvorna som presenteras i resultatet, är den termiska och elektriska verkningsgraden approximativt 48.0-53.4% respektive 19.0-19.2% för en reducerad temperatur med värdet noll, en solstrålning mellan 800-1000 W/m2, för en massflödeshastighet på 0.026 kg/sm2 som beslutades som den mest lämpliga för att öka den termiska prestandan. Resultaten resulterade i en värmeavledningsfaktor (FR) och total värmeförlustkoefficient (UL) på 0.56-0.62 respektive 53.4-53.5 W/m2 K. Resultaten på PVT-panelens prestanda under olika väderförhållanden visar att vattnets inloppstemperatur kan påverka drifttiden och mängden termisk energi som kan extraheras under året avsevärt, speciellt i nordiskt klimat. För att bedöma korrektheten i resultaten och den skapade modellen rekommenderas experimentell testning av den studerade PVT-panelen.

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Schelin, Eric. "PHOTOVOLTAIC SYSTEM YIELD EVALUATION IN SWEDEN : A performance review of PV systems in Sweden 2017-2018". Thesis, Mälardalens högskola, Akademin för ekonomi, samhälle och teknik, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-44667.

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The goal of this study is to evaluate Swedish photovoltaic systems regarding energy production from two different years and compare the gathered data with results from a model simulating optimal conditions. This is done to investigate how the energy production differs between each year, why there are differences, and also to evaluate the simulation tools compared to the real production data. A good way to measure performance is to calculate the specific yield, that is the energy produced per unit of installed power (kWh/kWp). In order to complete this study, a literature study was made to investigate reasons for potential variations in PV system yield. Besides that, the production data from 2373 PV systems in Sweden were collected from different databases, and the data were sorted and compiled in order to calculate specific yield (kWh/kWp). The total number of PV systems after sorting was 828 for the 2017-2018 data and 1380 systems for the 2018 data. Data from real PV system production was compared with calculations performed in two simulation tools, PVGIS and PVsyst. Differences in calculation methods were investigated for performance evaluations between the two programs, and also for comparison with the real plant data. The results showed that the average specific yield for Sweden as a whole, to be 798 kWh/kWp for 2017. For 2018 with the results where 890 kWh/kWp when looking at the exact same plants as for 2017. This is an increase of 11,5%. For the simulation tools the results where 974 kWh/kWp for PVGIS, and 978 for PVsyst for an optimized system. Larger variations in specific yield occurs between every of the 21 counties in Sweden. The solar irradiations show significant correlations to the variations of the 2017 and 2018 specific yield data. Differences between the production data from the two years and the simulation tools wereinvestigated further. Reasons for this was discussed to be because of orientations of the panels and shading of the panels. Real PV systemsdiffer in orientation and the amount of shadowing from the simulated calculations.

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Lai, Chi-Ming. "Development and thermal performance assessment of the opaque PV façades for subtropical climate region". 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/204562.

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Hassan, Daher Daha. "Modélisation et analyse expérimentale d'une centrale solaire photovoltaïque en milieu désertique maritime". Thesis, Lyon, 2017. http://www.theses.fr/2017LYSEI102/document.

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L'objectif de ce travail a été de développer un modèle pour prédire le comportement d'une installation photovoltaïque (PV) dans une zone désertique maritime, afin d'optimiser la production instantanée et de maintenir les performances au fil du temps. Les données issues du monitoring d’une centrale solaire ont été analysées afin d’en extraire des indicateurs de performances et d’étudier l'impact des facteurs climatiques (température, irradiation et dépôts de poussière). Les méthodes d'analyse de performance, telles que la "transposition aux conditions de référence" (Ex. PVUSA) et "estimation des mesures de performance" (Ex. PR) ont été appliquées pour évaluer le taux de dégradation annuel de l'installation. Une première indication de la durée de vie des installations PV pour le climat de Djibouti a été obtenue, ainsi qu'une capacité à prédire l'évolution à long terme de cette centrale et des futures installations PV. Parallèlement, un modèle numérique de l'installation PV a été construit en utilisant TRNSYS, incluant les modules et les onduleurs, pour retranscrire le comportement du système PV dans son ensemble, ainsi que les conditions environnementales dans lesquelles il évolue. Le modèle inclus dans la bibliothèque TRNSYS a été amélioré à l'aide de résultats expérimentaux, en particulier en ce qui concerne la dépendance thermique. Un modèle prédictif a donc été développé combinant l'accumulation de poussière, un modèle empirique de températures et de dégradation du module. Enfin, une étude paramétrique a été réalisée avec le modèle complet, afin d'évaluer l'impact du nettoyage pour divers scénarios d’empoussièrement. Les résultats contribueront à l'optimisation de la conception et de l'exploitation des centrales solaires dans ce type de climat
The objective of this work has been to develop a model for the behavior of a photovoltaic (PV) plant in an arid zone, to optimize instantaneous production and maintain performance over time. Monitoring data were collected for a solar power plant, which were then studied to infer the impact of climatic factors (temperature, irradiation and dust deposits). Performance analysis techniques including "transposition to reference conditions" (eg. PVUSA) and "estimation of standard performance measures" (eg. PR) were applied to evaluate the annual degradation rate of the facility. A first indication of expected lifetime of PV installations for the climate of Djibouti was thus obtained, as well as a capacity to predict the long-term evolution of the plant and future installations. In parallel, a numerical model of the photovoltaic installation was constructed using TRNSYS, including the modules and inverters, to transcribe the behavior of the PV system as a whole, and also the environmental conditions in which it evolves. The model included in the standard TRNSYS library was improved with the aid of experimental results, in particular with regards the thermal dependence. A predictive model was thus developed combining dust accumulation, an empirical model of module temperatures and degradation. Finally, a parametric study was undertaken with the complete model, to evaluate the impact of cleaning schedules under various dust scenarios. The results will contribute to the optimization of solar power plant design and operation in this type of climate

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Tylecote, Radomir. "Ownership and innovation in Chinese solar photovoltaic firms : an analysis of the effects of state, private, and foreign shareholding on patenting performance". Thesis, Imperial College London, 2014. http://hdl.handle.net/10044/1/26286.

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This thesis is a quantitative study of the effect of ownership - by state, private and foreign shareholdings - on innovation by China's solar photovoltaic (PV) firms. Using the country's solar PV industry, I seek to explain the impact of proportions of these different types of shareholding (and within the state category shareholding by central, provincial, and municipal governments) on innovative capacity. This capacity is measured by firms' rates and qualities of patenting. As Chinese economic growth falters, amid the 're-shoring' of certain manufacturing capabilities, the role of the state, and whether it is helping or hindering its economy's - and Chinese firms' - technological upgrading, is a vital question. This is particularly true in high-tech sectors, including solar PV, which the Chinese government deems essential for the country's continuing economic growth. Through the solar PV industry, we investigate the role of the state, and how it is helping or hindering Chinese companies' innovation. We employ a dataset covering 150 solar photovoltaic firms. This combines current and historical shareholding data for each firm, R&D expenditure data, and the firms' patent output (all Chinese-registered patents and their related foreign registrations). The thesis employs a principal-agent theoretical template for the unique Chinese politico-economic context, developing this theoretical approach for the particular 'multi-principal' scenario in Chinese high-tech firms (here we refer not only to the combinations of private and state principals, but also to the impact of local against central government). We demonstrate that higher state shareholding leads to higher R&D spending relative to the size of solar PV firms; among state shareholding, local state ownership is shown to be better than central state ownership at generating innovation (which we measure as patent performance). Firms that combine private and state shareholding, especially minority state-owned firms, are superior innovators than purely private or purely state-owned firms. For particularly innovative patenting, foreign shareholding was found to be beneficial, and finally, central state ownership was more likely to lead to the generation of the less challenging types of solar PV technologies, whereas local state ownership was more likely to lead to 'core' PV technologies being patented.

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Penaka, Santhan Reddy. "Digital mapping of techno-economic performance of a liquid-based solar photovoltaic/thermal (PVT) system over large geographical cities around the world". Thesis, Högskolan Dalarna, Energiteknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:du-34513.

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Photovoltaic thermal (PVT) collectors are widely used to harness a large fraction of the solar spectrum to generate electricity and heat from a single collector. The circulation of the working medium will pass through the collector which cools down the PV cell temperature and also increases the water temperature, which will increase the electrical and thermal performance at the same time. PVT is an emerging technology and is demonstrated for domestic and industrial applications. There has also been a major gap for the techno-economic analysis of PVT system in different climatic conditions and further developing reliable financial models that can be applied in different regions. This thesis paper presents a techno-economic evaluation of a liquid-based PVT collector system developed by Abora Solar, Spain across a wide range of climatic conditions and contexts. The various performance indicators are visualized by digital mapping approach for 86 different locations all over the world. The databank obtained from the analysis is further used to establish a general correlation between collector performance and meteorological parameters such as Global horizontal irradiation and ambient temperature. The collector energetic performance is simulated using a validated and proprietary simulation tool developed by Abora Solar company. The complete energy system consists of a PVT collector, a water storage tank, and the associated DHW demand simulator. The collector energetic performance has reflected following the analysed Global horizontal irradiation and ambient temperature trend. The highest and lowest energy utilization ratio of the collector has been recorded in Reykjavik, Iceland (63%) and Medina, Saudi Arabia (54%) respectively. The highest and lowest exergetic efficiency of the collector has been recorded in Reykjavik, Iceland (23%) and Medina, Saudi Arabia (17%) respectively. The exergetic efficiency collector has shown better performance with the less ambient temperature and less quality of work in high ambient temperatures. Furthermore, the energy utilization ratio and exergetic efficiencies of collector production are analysed. The economic analysis is carried out in realistic approach using two different financial scenarios: mode (1) The total system cost is capital investment in the first year; mode (2) Only 25 % of total system cost is a capital investment and remaining 75 % investment is considered with financing period with certain interest rate. The economic performance of the collector has been decided mainly based on the Net Present Value per unit collector area, whereas it expressed high dependency on thermal energy savings. The average NPV per unit collector area of 86 geographical cities for first financial model 1 and financial model 2 are 1886€ and 2221€ respectively. Besides, the Payback Period has also been estimated for the first financing model in all selected locations. The first financial model (1) has shown better results in locations with a high interest rate and highly recommended for the locations with interest rate. The significant work of understanding of PVT components behaviour at the system level, the collector energetic and economic performance at different climatic conditions across the world have been highlighted which reflects the concrete developments to this research subject area and helps market decision-makers for market penetration.

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Tanesab, Julius. "The effect of dust on the performance of solar photovoltaic module: Case studies in Nusa Tenggara Timur, Indonesia and Perth, Western Australia". Thesis, Tanesab, Julius (2018) The effect of dust on the performance of solar photovoltaic module: Case studies in Nusa Tenggara Timur, Indonesia and Perth, Western Australia. PhD thesis, Murdoch University, 2018. https://researchrepository.murdoch.edu.au/id/eprint/40274/.

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The performance of a PV module tends to decrease as dust impinges onto its cover surface. The attached dust diminishes the illumination by absorbing and scattering sunlight received by the solar module. Degradation caused by dust is temporary, but it should not be underestimated. Many studies investigated the influence of dust accumulation on optical properties and its impact on PV module performance. However, less attention was given to the effect of dust on small scale PV systems such as residential systems. Also, most of the preceding literature were not supported with an economic analysis which can inform maintenance activity scheduling. This study aims to identify the effect of dust on the performance of solar PV modules in varying environmental conditions and cost effective maintenance schedule for both solar home system and residential grid-connected system. To study the effect of dust on PV performance in different climate areas, research was conducted in Nusa Tenggara Timur (NTT), Indonesia and Perth, Western Australia. A series of experiments in the laboratory was performed. A solar simulator was used to measure PV modules‟ performance. A combination of a spectrophotometer, scanning electron microscope, electron dispersive spectroscope and an X-ray diffraction machine were used to examine properties of dust. In addition to the laboratory experiments, a field study was carried out to investigate the effect of dust accumulated naturally on PV performance degradation deployed in the two regions. Characterization results revealed that dust in Perth exhibited angular shapes dominated by quartz, while porous particles with a large amount of calcium oxide were observed in dust from NTT. The grain size analysis showed that the percentage of clay and very fine silt of dust from Perth was higher than that from NTT. Therefore, at the same density, dust from Perth passed less light than that from NTT. Power output produced by PVs coated artificially with dust from Perth was lower than that from NTT although the difference was not statistically significant. The performance degradation of PV modules deployed in the field varied with season. In Perth, power output of the modules which was maximal at the beginning of summer decreased significantly at the end of the season. The performance was then increased, approaching the initial position at the end of autumn and reached a peak at the end of winter. A similar decrease in the summer‟s performance was observed in the modules at the end of spring. In NTT, the performance which was maximal at the beginning of wet season dropped slightly at the end of the season and had significantly decreased at the end of the dry season. PV performance variations were in agreement with dust density deposited on the examined PV modules. Seasons with less rainfall demonstrated more accumulation of dust compared to those with greater rainfall. In addition, as the tilt angle increased dust deposition decreased; as a result, the average transmittance of dust increased. For a one year period, power loss of PV modules due to dust was 4 - 6% and 16 - 18% for Perth and NTT, respectively. The greater degradation in NTT is attributed to the lower tilt angle of the PV modules, the higher relative humidity, and the longer dry season in the region. The effect of dust on PV performance for a long time period carried out in Perth revealed that the degradation of Pmax output of PV samples deployed for almost 18 years without any cleaning procedures were 8 - 12%. These losses are higher than that measured for the one year period and indicate that natural cleaning agents such as rain and wind could not remove dust particles attached on the surface of the PV modules perfectly. In addition to the power decrease, observation results in the field showed that the modules exhibited some permanent degradation indicated by corrosion, delamination, and discoloration. This may be attributed to hot spot phenomenon caused by dust for a long time period besides the age of the examined PV modules. Economic analysis revealed that annual cost of production losses of residential PV systems in Perth and NTT with a degradation pattern as measured in the field was higher than the maintenance cost activities. Consequently, the system in Perth needs once cleaning in a year, meanwhile twice for the system in NTT. This thesis, therefore, suggested more intense cleaning should be applied for PV modules mounted at lower latitude and deployed in a tropical climate area. Standard dust de-rating factor (5%) stipulated by Australian/New Zealand Standard 4509.2:2010 was appropriate for modelling a grid-connected PV system in Perth, but, the system required cleaning once per year. Conversely, the standard soiling loss factor of 5% was not suitable for solar home system modelling in NTT as the estimation of the impact of dust was underestimated. Thus, this thesis recommended that the soiling de-rating factor should vary between regions and with season. This will improve the accuracy and the reliability of PV system models.

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SHARMA, MANISH KUMAR. "AMELIORATION OF SOLAR PHOTOVOLTAIC PERFORMANCE WITH MATLAB/SIMULINK". Thesis, 2017. http://dspace.dtu.ac.in:8080/jspui/handle/repository/15982.

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Solar energy, a boon for mankind is available in abundance on earth. To drive & improve the quality of human life, energy security is a prima facie requirement, due to which research on solar photovoltaic technology is growing steadily liaising with implementation of solar power plants across the world. In this dissertation extensive study is given to review the solar photovoltaic module efficiency & ameliorate the optimized output of 500kWP solar power plant by flexible tuning of distinct parameters and plant’s operation strategy dealing with the site topography, environmental considerations and cost reduction. Explicitly it is step by step analysis of solar photovoltaic cells/modules/arrays and their operating characteristic with Matlab/Simulink. The variation of physical parameters in real time & efficiency of solar photovoltaic system for different operating conditions is analyzed using experimental method to optimize solar photovoltaic efficiency, whereas striving for cost reduction with O&M activities. Real time experimental results further reveal that an increase of 3.7% in annual energy output is achieved over conventional flat system.

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Kandhway, Vikash. "Performance Analysis Of A Photovoltaic Powered Cold Store". Thesis, 1997. https://etd.iisc.ac.in/handle/2005/2146.

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