archives@tulane.edu / As global energy consumption continues to grow, new paths towards renewable energy generation are needed to reduce environmental impact and allow for more zero-net energy development. This includes not only electricity generation but also energy required for thermal applications. This dissertation explores three different technologies to generate electricity and high temperature heat simultaneously by using an actively tracked parabolic dish concentrator (2.72 m2) and an all-in-one hybrid receiver. This hybrid receiver usually consists of two key components, a PV module assembled with multijunction solar cells based on III-V materials, and a thermal receiver that transfers absorbed solar energy into a working fluid for a variety of commercial and industrial process heating applications. A key goal of this work is to use spectrum splitting and other design innovations to operate PV cells at much lower temperatures than the thermal receiver output temperatures. PV cooling is critical for PV modules to sustain high energy conversion efficiencies and to work for longer duration under concentrated light. A key distinction in different designs reported here is how the PV cells are cooled, either “transmissive microfluidic cooling”, “transmissive direct fluid cooling”, and “non-transmissive microfluidic cooling”. All three technologies show good performance for both efficient PV cooling (< 120°C) and high system energy conversion efficiency (> 80%). This dissertation is divided into four key chapters. Chapter 2 discusses spectrum splitting CPV with transmissive microfluidic cooling, focusing on the optical performance of the PV modules. By applying a transfer matrix-style approach, the cumulative transmission through the entire PV module is calculated: these results are verified experimentally. By doing so, the power collected by the PV cells and thermal receiver can be predicted. Chapter 3 explores a spectrum splitting hybrid receiver design using a cheaper and more straightforward cooling method that flows silicone oil across PV cells to extract their waste heat and to eliminate the use of sapphire for cost reduction. The cooling performance is verified by outdoor tests and the system efficiencies are discussed under different solar concentration. Chapter 4 investigates another hybrid receiver design that utilizes waste heat from high efficiency PV cells to preheat the working fluid in the thermal receiver instead of dumping the energy to surroundings as in the previous two methods. This design allows both the cells and the thermal receiver to be illuminated with concentrated sunlight simultaneously without the need for spectrum splitting. The electrical and thermal performance are tested both in the lab and outdoors. Chapter 5 discusses a proposed way to enhance the transmission of the spectrum splitting III-V solar cells used in Chapters 2 and 3. Epitaxial lift-off is used to remove the III-V cell substrate and to fabricate highly infrared-transmissive, spectrum-splitting thin-film solar cells. In summary, we explore the power collection performance, including optical, electrical, and thermal aspects, for these hybrid solar receiver technologies, enabling their use in a number of promising applications. / 1 / Yaping Ji

I en tid med allt mer påtagliga miljöhot, ökande CO2-utsläpp och stigande efterfrågan på el är det viktigt att utvecklingen av billig och effektiv förnyelsebar energi fortsätter runt om i världen för att kunna konkurrera mot billigare, icke förnyelsebara, energikällor. Ett steg i detta är att utveckla och effektivisera solkraft till den nivån att länder och företag väljer att investera i solkraft. Mer konkret kan det ske igenom utveckling av nya, mer effektiva, solcellsmoduler. I denna studie ska en ny typ av solcellsmodul, SmartPlus – utvecklat av Innotech Solar, jämföras mot deras standardmodul EcoPlus för att undersöka om den nya modulen kan bidra till högre andel solkraftsgenererad el i Sverige och där med minska CO2-utsläppen. Den nya solcellsmodulen är framtagen för att bättre kunna hantera och ta tillvara på solinstrålningen om en del av modulen utsätts för skugga, därför kommer studien simulera de båda moduler i en solpark där det sker intern skuggning mellan modulraderna. Skuggning av solcellsmoduler leder idag till stora förluster i elproduktionen på grund av nuvarande modellers konstruktion och syftet med studien är att undersöka om den nya solcellsmodulen är effektivare än den standardmodul som används för tillfället. Målet med studien är att skapa och verifiera en simuleringsmodell och simulera en solpark i Sverige där resultatets variation baseras på radavståndet mellan modulraderna och om modulerna är vertikal eller horisontellt placerade för att åstadkomma en variation av skuggning. Den solpark som ger högst elproduktion är en solpark med SmartPlus-moduler horisontell modulplacering, men då tillgången på markyta ofta en begränsande faktor bör vertikal modulplacering alltid föredras. Resultatet visar dock att i valet av modul till en solpark är inte valet mellan SmartPlus och EcoPlus den viktigaste faktorn. Även om SmartPlus genomgående har en högre elproduktion på årsbasis är skillnaden marginell till EcoPlus, däremot har faktorer som radavstånd och modulplacering en större inverkan på elproduktionen och effektiviteten i solparken. / In an era of significant environmental threats, increasing carbondioxide emissions and rising electricity demand, it is important that the development of cheap and efficient renewable energy continues around the world to compete against cheaper, non-renewable, energy sources. To do this, the development of solar power have to continute so that countries and companies choose to invest solar power insteed of non-renewable energy. More specifically, it can be done through the development of new, more efficient, solar  cells modules. In this study, a new sort of solar cell module, SmartPlus - developed by Innotech Solar, is compared to their standard module EcoPlus to investigate whether the new module may contribute to the higher proportion of solar-generated electricity in Sweden and there by reducing carbondioxide emissions. The new photovoltaic module is designed to take better advantage of the solar radiation when a portion of the module is exposed to shade, therefore will this study simulating the two modules in a solar panel plant where there is internal shading between the rows. Shading of photovoltaic modules currently leads to substantial losses in electricity generation because of the modules design and the purpose of the study is to investigate whether the new photovoltaic module are more efficient than the standard solar module that currently is in use. The aim of the study is to create and verify a simulation model and simulate a solar park in Sweden where the results variation depends on the spacing between the rows in the solar panel plant and if the modules are vertically or horizontally positioned to provide a variety of shading. The solar park that provides maximum power generation is a solar park with SmartPlus modules with horizontal position, but since the availability of land is often a limiting factor the vertical position should always be preferred. The result shows that when choosing module to a solar the choice between SmartPlus and EcoPlus is not the most important factor. Even though SmartPlus consistently has a higher electricity production on an annual basis, the difference is marginal to EcoPlus, however, factors such as row spacing and module placement have a far greater impact on electricity generation and efficiency of the solar panel plant.

Αντικείμενο της παρούσας διπλωματικής εργασίας είναι η μελέτη λειτουργίας των φωτοβολταϊκών γεννητριών υπό συνθήκες χαμηλής έντασης ακτινοβολίας όχι όμως ελεγχόμενης, δηλαδή σε εσωτερικό χώρο, αλλά εκτεθειμένο σε εξωτερικό χώρο και με απρόβλεπτες εναλλαγές έντασης. Επιπλέον το υποβάλαμε σε μερική σκίαση με διαφορετική διάταξη κάθε φορά προκειμένου να διαπιστώσουμε τη λειτουργία του και το πώς αυτό συμπεριφέρεται, προκειμένου να κατανοήσουμε το πόσο σημαντικό είναι να ακολουθούνται οι προδιαγραφές εγκατάστασης για να παίρνουμε την μέγιστη απόδοση από τις φωτοβολταϊκές γεννήτριες. Για το σκοπό αυτό είχαμε στη διάθεσή μας ένα φωτοβολταϊκό πλαίσιο, το οποίο αποτελούνταν από 36 στοιχεία και μια βάση κινητή για να το τοποθετήσουμε με σκοπό να το προσανατολίζουμε σωστά ακολουθώντας την πορεία του ηλίου και την οποία την κατασκευάσαμε εξ αρχής. Στη συνεχεία απαραίτητη ήταν η κατασκευή δύο κυκλωμάτων, ενός “I-V tracer” και ενός “Ramp Generator” μέσα στο ίδιο κουτί, προκειμένου να συνδέσουμε επάνω σε αυτό όλες τις συσκευές μας για να καταγράψουμε τις σειρές των μετρήσεών μας που μας έδιναν οι διάφορες συσκευές μας καθώς και το φωτοβολταϊκό κατά τη διάρκεια της έκθεσής του στην ηλιακή ακτινοβολία. Ακόμα, σημαντικό κομμάτι αποτέλεσε και ο προγραμματισμός του Data Logger έτσι ώστε να καταγράφονται σωστά η τάση, το ρεύμα, οι θερμοκρασίες και η ακτινοβολία κάθε στιγμή του πειράματός μας για να τα εκμεταλλευτούμε και να εξαγάγουμε σωστά συμπεράσματα. Τέλος μπορούμε να πούμε πως η επιλογή ιδανικών ημερών ήταν ένα δύσκολο κομμάτι και η υπομονή που απαιτούσε το πείραμά μας ήταν ένας καλός σύμμαχος για την ολοκλήρωσή του. / -

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Σκοπός της παρούσας διπλωματικής είναι να μελετήσουμε την επίδραση της θερμοκρασίας στα ηλεκτρικά χαρακτηριστικά διαφορετικών τύπων φωτοβολταϊκών πλαισίων σε συνθήκες πραγματικής λειτουργίας μέσα από τα αριθμητικά αποτελέσματα των μετρήσεων. Αρχικά αναφέρονται οι πηγές ενέργειας και γίνεται μία ιστορική αναδρομή του φωτοβολταίκού φαινομένου. Στη συνέχεια αναλύεται η συμπεριφορά των ημιαγωγών, τα είδη και οι τεχνολογίες των φωτοβολταϊκών κυττάρων συμπεριλαμβανομένων εκείνων που μελετάμε. Τα φωτοβολταϊκά πλαίσια που χρησιμοποιήθηκαν σε αυτή την εργασία είναι το πλαίσιο δισεληνοϊνδιούχου χαλκού(CIS) SHELL ECLIPSE 75-C, το πλαίσιο μονοκρυσταλλικού πυριτίου Conergy Q 80 MI και το πλαίσιο πολυκρυσταλλικού πυριτίου Sharp NE-80E2E. Πραγματοποιήσαμε μετρήσεις των ηλεκτρικών μεγεθών σε ποικίλες καιρικές συνθήκες. Οι μετρήσεις έγιναν στην ταράτσα του κτιρίου των Ηλεκτρολόγων μηχανικών και τα πλαίσια ήταν προσανατολισμένα προς το Νότο καθώς η Ελλάδα βρίσκεται στο Βόρειο ημισφαίριο της γης. Επίσης η κλίση των πλαισίων ήταν σταθερή στις 38ο που είναι ίση με το γεωγραφικό πλάτος του τόπου. Οι μετρήσεις, οι οποίες λήφθηκαν με τη βοήθεια συσκευής χάραξης καμπύλων I-V, έγιναν για 9 μήνες (από τον Μάρτιο έως το Νοέμβριο του 2011) και είχαν διάρκεια όλη την ημέρα. Μετρήσεις έγιναν και σε ηλιόλουστες και σε συννεφιασμένες μέρες. Τα δεδομένα που λάβαμε μας οδήγησαν σε συμπεράσματα σχετικά με το πώς η θερμοκρασία πλαισίων επιδρά στα ηλεκτρικά μεγέθη που επηρεάζουν την απόκριση των πλαισίων. Στη συνέχεια υπολογίζεται η μηνιαία αποδιδόμενη ενέργεια των πλαισίων με τη βοήθεια των πειραματικών δεδομένων μας αλλά και με τη βοήθεια του προγράμματος PV SOL μέσω του οποίου μοντελοποιήσαμε το σύστημά μας για να συγκρίνουμε τα αποτελέσματα. / The aim of this diploma thesis is to study the effect of temperature on the electrical characteristics in different types of photovoltaic modules. First, energy sources and the history of the photovoltaic phenomenon are analyzed. Secondly, the behavior of the semiconductors, the types and the technologies of the photovoltaic cells are analyzed, including the cells that we are studying. In this work we used one module of copper indium diselenide (CIS) SHELL ECLIPSE 75-C, one module of Monocrystalline Silicon Conergy Q 80 MI and one module of Polycrystalline Silicon Sharp NE-80E2E. These measurements of the electrical characteristics of the above solar modules were carried out under several weather conditions. The measurements have been realized on the roof of the building of the department of Electrical and Computer Engineering at the University of Patras and the orientation of the modules was always South. The modules were placed at tilt angle of 38o, which is equal to the latitude. These measurements have been realized during nine months (March - November 2011), using a device that enables the measurement of the Ι – V curve. Conclusions were extracted about the effect of temperature on the electrical characteristics that have influence on the electrical response of the modules. Moreover, we estimated the energy produced by the solar modules during the measurements. In the final part of this thesis, we tried to simulate our photovoltaic system in order to compare the measured results to the experimental, by using the computer modeling system PV SOL.

A geração de energia fotovoltaica continua em crescimento e por isso estudos relacionados à aplicação de diferentes tecnologias fotovoltaicas se tornam muito importantes. A tecnologia de células fotovoltaicas de silício cristalino representa a maior parte da aplicação de energia solar fotovoltaica atualmente. Os módulos com tecnologias de filmes finos foram apresentados ao mercado como uma nova geração de módulos e atualmente são referenciados como módulos fotovoltaicos de segunda geração. As tecnologias de filmes finos possuem algumas vantagens em relação ao silício cristalino, como por exemplo: menor quantidade de material, menor custo de produção e possibilidade de se produzir células e módulos flexíveis, embora em geral apresentem eficiências menores. Existem tecnologias de filmes finos aplicadas à geração fotovoltaica que apresentam instabilidade quando expostas à radiação solar, variando a potência gerada do módulo nas primeiras horas de exposição. Esses efeitos motivaram a padronização de um ensaio de exposição solar, do inglês light-soaking, que atualmente é previsto por uma norma internacional de qualificação de módulos fotovoltaicos (IEC 61646). Neste trabalho, desenvolveu-se uma metodologia para realizar o ensaio lightsoaking e construiu-se uma bancada de testes para obter resultados experimentais a partir de módulos expostos na cobertura do prédio anexo do LABSOL. Para isso, foi realizada uma análise de área livre de sombra disponível, bem como montada a estrutura metálica de sustentação para os módulos. Também foram instaladas resistências elétricas para dissipação de potência dos módulos e montado painel elétrico dentro do prédio centralizando as conexões necessárias. O experimento também contou com o desenvolvimento de um programa em linguagem Visual Basic® para interagir com os instrumentos de medição e realizar o monitoramento do ensaio. Neste trabalho foram ensaiados quatro módulos com diferentes tecnologias de filmes finos, as quais: silício amorfo com tripla junção, silício amorfo com uma junção, CIGS (Disseleneto de Cobre, Índio e Gálio) e por último dupla junção de silício amorfo com silício microcristalino. O experimento foi conduzido por 55 dias, sendo que a cada minuto o programa registrou dados de irradiância, irradiação acumulada e temperatura dos módulos. Ao final do experimento, os módulos receberam no total 347 kWh/m2 de irradiação e, durante o ensaio, foram realizadas ao todo 8 medições de curva característica corrente versus tensão para verificar o desempenho dos módulos. Antes e após a exposição, também foram realizadas medições em um simulador solar a fim de se obter medidas em condições controladas de temperatura e irradiância. Ao aplicar o critério de estabilização previsto na norma IEC 61646, verificou-se que todos os módulos o atenderam. Contudo, os módulos com tecnologia de uma junção de silício amorfo e com tecnologia de tripla junção de silício amorfo voltaram a apresentar degradação acima do máximo estabelecido pela norma IEC 61646 após continuarem expostos à radiação solar. Sendo assim, pode ser necessário alterar o critério para um maior valor de irradiação acumulada entre cada avaliação de degradação destes módulos, principalmente quando o ensaio é realizado com temperatura externa elevada. A metodologia mostrou que esse ensaio pode ser realizado em ambiente externo com luz natural de maneira prática e econômica, porém realizar as medições de curva característica com luz natural e temperatura não controlada implica em adicionar algumas incertezas ao ensaio. / The photovoltaic (PV) power generation continues to grow and so studies related to the application of different photovoltaic technologies become very important. The crystalline silicon solar cells technology is the most current application of PV power generation. The photovoltaic modules with thin film technologies were presented to the market as a new generation of modules and are currently referred to as second generation PV modules. The thin film technologies have some advantages compared to crystalline silicon, for example, less material, lower cost of production and ability to produce flexible cells and modules, although generally have lower efficiencies. There are thin film technologies for photovoltaic conversion that show instability when exposed to the sun, varying the power generated in the early hours of sun exposure. These effects led to the standardization of a sun exposure test, the light-soaking test, which is currently standardized by an international standard of qualification of photovoltaic modules (IEC 61646). In this study, we developed a methodology to perform the light-soaking test and built a workbench to obtain experimental results from PV modules set out in the LABSOL building. For this purpose, a shadow analysis was performed as well as the metal structure mounted to support the photovoltaic modules. Resistive loads were also installed in order to dissipate the power of the modules. An electrical panel was mounted inside the building to centralize the necessary connections. The workbench also included the development of a program in Visual Basic® to interact with the measuring instruments and carry out the monitoring of the experiment. In this work we tested four modules with different thin film technologies, including: triple junction amorphous silicon, single junction amorphous silicon, CIGS (Copper Indium Gallium Diselenide) and tandem junction of amorphous silicon and microcrystalline silicon. The experiment was conducted over 55 days, and every minute the program recorded irradiance data, accumulated irradiation and module temperature. At the end of the experiment, the modules received 347 kWh/m2 of irradiation. During the test, there were a total of 8 characteristic curve (I x V) measurements to verify the performance of the modules. Before and after exposure, were also performed measurements in a solar simulator. By applying the stabilization criteria presented in IEC 61646 it was found that all the modules have been considered stabilized. However, after being exposed to more hours of sunlight, the single junction amorphous silicon module and the triple junction amorphous silicon module presented degradation above the maximum established by IEC 61646 standard. Thus, it may be necessary to change the criteria for a higher value of accumulated irradiation between assessments of degradation of these modules, especially when the test is performed with high external temperature. The methodology showed that this test may be performed outdoors under natural light in a practical and economical way, but the characteristic curve measurements with natural light and uncontrolled temperature add some uncertainty to the test.

abstract: Photovoltaic (PV) module degradation is a well-known issue, however understanding the mechanistic pathways in which modules degrade is still a major task for the PV industry. In order to study the mechanisms responsible for PV module degradation, the effects of these degradation mechanisms must be quantitatively measured to determine the severity of each degradation mode. In this thesis multiple modules from three climate zones (Arizona, California and Colorado) were investigated for a single module glass/polymer construction (Siemens M55) to determine the degree to which they had degraded, and the main factors that contributed to that degradation. To explain the loss in power, various nondestructive and destructive techniques were used to indicate possible causes of loss in performance. This is a two-part thesis. Part 1 presents non-destructive test results and analysis and Part 2 presents destructive test results and analysis. / Dissertation/Thesis / Masters Thesis Engineering 2015

A geração de energia fotovoltaica continua em crescimento e por isso estudos relacionados à aplicação de diferentes tecnologias fotovoltaicas se tornam muito importantes. A tecnologia de células fotovoltaicas de silício cristalino representa a maior parte da aplicação de energia solar fotovoltaica atualmente. Os módulos com tecnologias de filmes finos foram apresentados ao mercado como uma nova geração de módulos e atualmente são referenciados como módulos fotovoltaicos de segunda geração. As tecnologias de filmes finos possuem algumas vantagens em relação ao silício cristalino, como por exemplo: menor quantidade de material, menor custo de produção e possibilidade de se produzir células e módulos flexíveis, embora em geral apresentem eficiências menores. Existem tecnologias de filmes finos aplicadas à geração fotovoltaica que apresentam instabilidade quando expostas à radiação solar, variando a potência gerada do módulo nas primeiras horas de exposição. Esses efeitos motivaram a padronização de um ensaio de exposição solar, do inglês light-soaking, que atualmente é previsto por uma norma internacional de qualificação de módulos fotovoltaicos (IEC 61646). Neste trabalho, desenvolveu-se uma metodologia para realizar o ensaio lightsoaking e construiu-se uma bancada de testes para obter resultados experimentais a partir de módulos expostos na cobertura do prédio anexo do LABSOL. Para isso, foi realizada uma análise de área livre de sombra disponível, bem como montada a estrutura metálica de sustentação para os módulos. Também foram instaladas resistências elétricas para dissipação de potência dos módulos e montado painel elétrico dentro do prédio centralizando as conexões necessárias. O experimento também contou com o desenvolvimento de um programa em linguagem Visual Basic® para interagir com os instrumentos de medição e realizar o monitoramento do ensaio. Neste trabalho foram ensaiados quatro módulos com diferentes tecnologias de filmes finos, as quais: silício amorfo com tripla junção, silício amorfo com uma junção, CIGS (Disseleneto de Cobre, Índio e Gálio) e por último dupla junção de silício amorfo com silício microcristalino. O experimento foi conduzido por 55 dias, sendo que a cada minuto o programa registrou dados de irradiância, irradiação acumulada e temperatura dos módulos. Ao final do experimento, os módulos receberam no total 347 kWh/m2 de irradiação e, durante o ensaio, foram realizadas ao todo 8 medições de curva característica corrente versus tensão para verificar o desempenho dos módulos. Antes e após a exposição, também foram realizadas medições em um simulador solar a fim de se obter medidas em condições controladas de temperatura e irradiância. Ao aplicar o critério de estabilização previsto na norma IEC 61646, verificou-se que todos os módulos o atenderam. Contudo, os módulos com tecnologia de uma junção de silício amorfo e com tecnologia de tripla junção de silício amorfo voltaram a apresentar degradação acima do máximo estabelecido pela norma IEC 61646 após continuarem expostos à radiação solar. Sendo assim, pode ser necessário alterar o critério para um maior valor de irradiação acumulada entre cada avaliação de degradação destes módulos, principalmente quando o ensaio é realizado com temperatura externa elevada. A metodologia mostrou que esse ensaio pode ser realizado em ambiente externo com luz natural de maneira prática e econômica, porém realizar as medições de curva característica com luz natural e temperatura não controlada implica em adicionar algumas incertezas ao ensaio. / The photovoltaic (PV) power generation continues to grow and so studies related to the application of different photovoltaic technologies become very important. The crystalline silicon solar cells technology is the most current application of PV power generation. The photovoltaic modules with thin film technologies were presented to the market as a new generation of modules and are currently referred to as second generation PV modules. The thin film technologies have some advantages compared to crystalline silicon, for example, less material, lower cost of production and ability to produce flexible cells and modules, although generally have lower efficiencies. There are thin film technologies for photovoltaic conversion that show instability when exposed to the sun, varying the power generated in the early hours of sun exposure. These effects led to the standardization of a sun exposure test, the light-soaking test, which is currently standardized by an international standard of qualification of photovoltaic modules (IEC 61646). In this study, we developed a methodology to perform the light-soaking test and built a workbench to obtain experimental results from PV modules set out in the LABSOL building. For this purpose, a shadow analysis was performed as well as the metal structure mounted to support the photovoltaic modules. Resistive loads were also installed in order to dissipate the power of the modules. An electrical panel was mounted inside the building to centralize the necessary connections. The workbench also included the development of a program in Visual Basic® to interact with the measuring instruments and carry out the monitoring of the experiment. In this work we tested four modules with different thin film technologies, including: triple junction amorphous silicon, single junction amorphous silicon, CIGS (Copper Indium Gallium Diselenide) and tandem junction of amorphous silicon and microcrystalline silicon. The experiment was conducted over 55 days, and every minute the program recorded irradiance data, accumulated irradiation and module temperature. At the end of the experiment, the modules received 347 kWh/m2 of irradiation. During the test, there were a total of 8 characteristic curve (I x V) measurements to verify the performance of the modules. Before and after exposure, were also performed measurements in a solar simulator. By applying the stabilization criteria presented in IEC 61646 it was found that all the modules have been considered stabilized. However, after being exposed to more hours of sunlight, the single junction amorphous silicon module and the triple junction amorphous silicon module presented degradation above the maximum established by IEC 61646 standard. Thus, it may be necessary to change the criteria for a higher value of accumulated irradiation between assessments of degradation of these modules, especially when the test is performed with high external temperature. The methodology showed that this test may be performed outdoors under natural light in a practical and economical way, but the characteristic curve measurements with natural light and uncontrolled temperature add some uncertainty to the test.

A geração de energia fotovoltaica continua em crescimento e por isso estudos relacionados à aplicação de diferentes tecnologias fotovoltaicas se tornam muito importantes. A tecnologia de células fotovoltaicas de silício cristalino representa a maior parte da aplicação de energia solar fotovoltaica atualmente. Os módulos com tecnologias de filmes finos foram apresentados ao mercado como uma nova geração de módulos e atualmente são referenciados como módulos fotovoltaicos de segunda geração. As tecnologias de filmes finos possuem algumas vantagens em relação ao silício cristalino, como por exemplo: menor quantidade de material, menor custo de produção e possibilidade de se produzir células e módulos flexíveis, embora em geral apresentem eficiências menores. Existem tecnologias de filmes finos aplicadas à geração fotovoltaica que apresentam instabilidade quando expostas à radiação solar, variando a potência gerada do módulo nas primeiras horas de exposição. Esses efeitos motivaram a padronização de um ensaio de exposição solar, do inglês light-soaking, que atualmente é previsto por uma norma internacional de qualificação de módulos fotovoltaicos (IEC 61646). Neste trabalho, desenvolveu-se uma metodologia para realizar o ensaio lightsoaking e construiu-se uma bancada de testes para obter resultados experimentais a partir de módulos expostos na cobertura do prédio anexo do LABSOL. Para isso, foi realizada uma análise de área livre de sombra disponível, bem como montada a estrutura metálica de sustentação para os módulos. Também foram instaladas resistências elétricas para dissipação de potência dos módulos e montado painel elétrico dentro do prédio centralizando as conexões necessárias. O experimento também contou com o desenvolvimento de um programa em linguagem Visual Basic® para interagir com os instrumentos de medição e realizar o monitoramento do ensaio. Neste trabalho foram ensaiados quatro módulos com diferentes tecnologias de filmes finos, as quais: silício amorfo com tripla junção, silício amorfo com uma junção, CIGS (Disseleneto de Cobre, Índio e Gálio) e por último dupla junção de silício amorfo com silício microcristalino. O experimento foi conduzido por 55 dias, sendo que a cada minuto o programa registrou dados de irradiância, irradiação acumulada e temperatura dos módulos. Ao final do experimento, os módulos receberam no total 347 kWh/m2 de irradiação e, durante o ensaio, foram realizadas ao todo 8 medições de curva característica corrente versus tensão para verificar o desempenho dos módulos. Antes e após a exposição, também foram realizadas medições em um simulador solar a fim de se obter medidas em condições controladas de temperatura e irradiância. Ao aplicar o critério de estabilização previsto na norma IEC 61646, verificou-se que todos os módulos o atenderam. Contudo, os módulos com tecnologia de uma junção de silício amorfo e com tecnologia de tripla junção de silício amorfo voltaram a apresentar degradação acima do máximo estabelecido pela norma IEC 61646 após continuarem expostos à radiação solar. Sendo assim, pode ser necessário alterar o critério para um maior valor de irradiação acumulada entre cada avaliação de degradação destes módulos, principalmente quando o ensaio é realizado com temperatura externa elevada. A metodologia mostrou que esse ensaio pode ser realizado em ambiente externo com luz natural de maneira prática e econômica, porém realizar as medições de curva característica com luz natural e temperatura não controlada implica em adicionar algumas incertezas ao ensaio. / The photovoltaic (PV) power generation continues to grow and so studies related to the application of different photovoltaic technologies become very important. The crystalline silicon solar cells technology is the most current application of PV power generation. The photovoltaic modules with thin film technologies were presented to the market as a new generation of modules and are currently referred to as second generation PV modules. The thin film technologies have some advantages compared to crystalline silicon, for example, less material, lower cost of production and ability to produce flexible cells and modules, although generally have lower efficiencies. There are thin film technologies for photovoltaic conversion that show instability when exposed to the sun, varying the power generated in the early hours of sun exposure. These effects led to the standardization of a sun exposure test, the light-soaking test, which is currently standardized by an international standard of qualification of photovoltaic modules (IEC 61646). In this study, we developed a methodology to perform the light-soaking test and built a workbench to obtain experimental results from PV modules set out in the LABSOL building. For this purpose, a shadow analysis was performed as well as the metal structure mounted to support the photovoltaic modules. Resistive loads were also installed in order to dissipate the power of the modules. An electrical panel was mounted inside the building to centralize the necessary connections. The workbench also included the development of a program in Visual Basic® to interact with the measuring instruments and carry out the monitoring of the experiment. In this work we tested four modules with different thin film technologies, including: triple junction amorphous silicon, single junction amorphous silicon, CIGS (Copper Indium Gallium Diselenide) and tandem junction of amorphous silicon and microcrystalline silicon. The experiment was conducted over 55 days, and every minute the program recorded irradiance data, accumulated irradiation and module temperature. At the end of the experiment, the modules received 347 kWh/m2 of irradiation. During the test, there were a total of 8 characteristic curve (I x V) measurements to verify the performance of the modules. Before and after exposure, were also performed measurements in a solar simulator. By applying the stabilization criteria presented in IEC 61646 it was found that all the modules have been considered stabilized. However, after being exposed to more hours of sunlight, the single junction amorphous silicon module and the triple junction amorphous silicon module presented degradation above the maximum established by IEC 61646 standard. Thus, it may be necessary to change the criteria for a higher value of accumulated irradiation between assessments of degradation of these modules, especially when the test is performed with high external temperature. The methodology showed that this test may be performed outdoors under natural light in a practical and economical way, but the characteristic curve measurements with natural light and uncontrolled temperature add some uncertainty to the test.

Com a expansão do emprego de módulos fotovoltaicos para geração energética, surge o desafio do descarte adequado desse resíduo de equipamento eletroeletrônico. Através da elaboração de um processo multietapas, esse desafio torna-se possível de ser abordado. O presente estudo possui o objetivo de recuperar os materiais presentes nos módulos fotovoltaicos de silício cristalino e de silício amorfo. Diversas técnicas de caracterização física e química foram empregadas para determinar-se composição dos módulos fotovoltaicos e consequentemente o fluxo de processos necessários para recuperação dos materiais identificados. Foi identificado que o módulo de silício cristalino possuía no semicondutor alguns metais como prata (na concentração de 0,063% em massa do módulo) e silício, e na fase polimérica polidimetilsiloxano como encapsulante e PET como backsheet. A separação e recuperação dos polímeros foi realizada através do uso da teoria de dissolução de solventes de Hildebrand, abordando aspectos termodinâmicos e cinéticos. A separação ocorreu em 24h a 860rpm mergulhando-se os módulos em isopropanol, podendo ocorrer separação em até 6h a 860rpm utilizando-se tetrahidrofurano. A lixiviação da prata a partir do semicondutor foi possível com ácido sulfúrico 4mol.L-1, 95°C, sob adição de 6mL de peróxido de hidrogênio a cada 15min, alcançando-se 100% de lixiviação em 2h. Alterando-se a temperatura para 30°C a lixiviação foi completa apenas em 6h de experimento Precipitou-se a prata em solução na forma de cloreto de prata com adição de cloreto de sódio. O módulo de silício amorfo continha EVA na fração polimérica e silício, germânio, prata, estanho e índio (concentração 0,34g/m2 do módulo) na fração metálica, observados tanto por micrografias quanto por análise química quantitativa. A calcinação a 400°C permitiu a remoção do EVA e liberação dos contatos de prata. A lixiviação de índio foi de 100% para uma solução 1mol.L-1 de ácido fosfórico a 75°C, sob 800rpm de agitação e relação sólido-líquido 1g.10mL-1 em 1h. / As the photovoltaic module market grows, an increasingly challenging scenario arises for solar modules end of life management. Such a scenario can be tackled through a process comprising multiple steps. This study has the objective to recover materials present in photovoltaic modules of crystalline silicon and amorphous silicon. Several characterization techniques (physical and chemical) were employed to determine the composition of the modules and thus the process flow needed to recover the identified materials. Along the process, it was noticed that the crystalline silicon module had in its semiconductor metals such as silver (in concentration of at least 0,063% in weight of module) and silicon. Also polydimethylsiloxane was identified as encapsulant and polyethylene therephtalate as backsheet. A separation and recovery of these materials was possible using the theory of solvent dissolution of Hildebrand, comprising thermodynamics and kinetics. The separation occurred in 24h at 860rpm, rising the modules in isopropyl alcohol and potentially reaching 6h at 860rpm when rising them in tetrahydrofuran. The silver leaching from the semiconductor phase was possible in sulphuric acid 4 mol.L-1, 95°C, under addition of 6mL of hydrogen peroxide every 15min, reaching 100% silver leached in 2h. Shifting the temperature to 30°C, the leaching would occur completely only after 6h of experiment. The silver was precipitated as a chloride from the solution by addition of sodium chloride. The amorphous silicon module showed that EVA was present in the polymeric phase and silicon, germanium, silver, tin and indium (the last one at concentration of 0,34g/m2 in area of the module) in the metallic phase, observed on the micrographies and chemical analyses. Calcination was performed at 400°C, removing the EVA and freeing the silver contacts. Indium was 100% leached with a 1mol.L-1 phosphoric acid solution at 75°C, under 800rpm and solid-liquid ratio of 1g.10mL-1 in 1h.