This research applies a recently developed dynamic state-estimation based protection scheme, the settingless protection, to the photovoltaic (PV) industry for the first time. At this time, the proposed protection algorithm has been implemented on traditional protection zones for individual power system devices, but this research extends this protection to a microgrid, specifically, a system of PV network composed of several PV modules. Several illustrative examples on various anomalies such as high impedance faults and shorted-out PV modules have been provided to demonstrate the effectiveness of this protection scheme. The detection of these anomalies has been demonstrated in the presence of changing atmospheric conditions, and with the operation of maximum power point tracking (MPPT) equipped dc-dc converters. This protection scheme requires an accurate model of the PV module, therefore, a two-diode PV model has been developed using quadratic integration modeling. In this PV model development, a scaling factor is applied to the Taylor series expansion of the exponential terms of the model of the PV module. Then the higher order terms of the Taylor series expansion are reduced to at most second order terms using the quadratization technique. Furthermore, a novel approach for extracting the PV parameters, namely, the ideality constants, leakage currents, PV module internal current, shunt and series resistances, has been presented. A comparison was performed between numerically generated data using the determined PV module parameters and data measurements from a physical PV module. It was shown that the maximum error from this comparison was below 0.12A, and less than 0.05A around the maximum power point region of the PV modules used for this research. The residual data from the PV array protection scheme has been used to develop a method for identifying the location of faulted PV modules. Also, condition-based monitoring of the PV array system has also been presented with examples. From the PV array system monitoring, the shading and underperformance of a PV module have been identified. From the contributions of this research, an accurate module of the PV array has been developed in a form that can be integrated with other power system devices. This accurate module can be used for state estimation of the PV array, load flow analysis, short circuit analysis, and other power system analytical studies. Also, by determining the location of the faulted PV module, the time to identify this faulted PV module in a large PV installation is drastically reduced. Lastly, by identifying shading conditions and underperforming PV modules, the PV system operator can quickly bring the underperforming module or modules to optimal performance, thereby, maximizing the power yield of the PV array, and maximizing the revenue of the PV system owner.

Transferring organic photovoltaics (OPV) from the laboratory into economically feasible products, requires the fabrication of modules, a series of connected single cells. During this transition, there is typically a drastic decrease in power conversion efficiency (PCE). This thesis reports on the design, fabrication, and characterization of state-of-the-art, high-performance organic photovoltaic modules with a novel geometry that composed of unit cells with alternating electrical polarities. Such configuration is realized by exclusive patterning of the interlayers and electrodes and avoids patterning of the photoactive layer. With this novel architecture, area losses of photovoltaic module can be significantly reduced compared with the conventional configurations. The processing of this new solar cell module is also compatible with large area processing techniques such as slot-die coating. This thesis reports on 4-cell and 8-cell modules, wherein the measured fill-factors (FF) and PCE of the constituent sub-cells and of the modules are almost identical. The 4-cell module, with a total area of 0.8 cm2, exhibits an open-circuit voltage (VOC) of 3.15 V, a short circuit-current density (JSC) of 2.3 mA/cm2 and a FF of 0.69, yielding a PCE of 5.01%. The 8-cell module, with a total area of 1.6 cm2, exhibits a VOC of 6.39 V, a JSC of 1.2 mA/cm2 and a FF of 0.63, yielding a PCE of 5.06%. Similar PCE values between 4-cell and 8-cell module is a demonstration of scalability of this novel geometry without compromising the efficiency.

Submitted by admin tede (tede@pucgoias.edu.br) on 2018-08-23T10:49:49Z No. of bitstreams: 1 FELIPE RABELO RODRIGUES ALVES.pdf: 2420637 bytes, checksum: 29b86a56944a6b8d8dd2f04052fb7420 (MD5) / Made available in DSpace on 2018-08-23T10:49:49Z (GMT). No. of bitstreams: 1 FELIPE RABELO RODRIGUES ALVES.pdf: 2420637 bytes, checksum: 29b86a56944a6b8d8dd2f04052fb7420 (MD5) Previous issue date: 2018-06-06 / The dependence on nonrenewable sources and concern about high levels of pollutant emissions encourage the use of systems that are derived from renewable resources. In this way, photovoltaic systems are seen as promising because they depend on a clean and abundant source, especially in areas of tropical climate, the solar radiation. However, the accumulation of soiling on the surfaces of photovoltaic modules is one of the main environmental factors that cause of the loss of efficiency of these systems, together with irradiance, temperature and shading. In this sense, the present work seeks to verify the soiling effects on the efficiency of photovoltaic modules, through data collection, measurement of specific parameters, statistical analysis and comparisons of scenarios of dirty and clean modules. For the verification and quantification of soiling interference in the efficiency of photovoltaic modules, the electrical and environmental parameters capable of characterizing them are obtained: Isc - Short circuit current (A); Voc - Open circuit voltage (V); G - Solar irradiance (W/m²); T - Module temperature (°C). From the results it can be observed that the intensity of the solar radiation has greater influence on the current of the module, while the temperature directly affects the voltage. This work showed that, in the universe studied, soiling has reduced the power generation efficiency of modules by 3,2% for accumulated soiling in periods of 45 days, and by 18% for accumulated soiling in a longer period of 3,5 years. The characterization of the soiling showed that in addition to mineral particles, there is also organic matter derived from biofilms, which makes it difficult to clean the modules by natural methods (rains and winds). Based on the bibliography and the tests realized, it is estimated that the periodicity of the hygiene should not exceed 60 days, with that, the effects of the soiling are reduced significantly. / A dependência por fontes não renováveis e a preocupação com os elevados níveis de emissões de poluentes estimulam o uso de sistemas que são provenientes de recursos renováveis. Com isso, são vistos como promissores os sistemas fotovoltaicos, por dependerem de uma fonte limpa e abundante, em especial em áreas de clima tropical, a radiação solar. Porém, o acúmulo de sujeira nas superfícies de módulos fotovoltaicos é um dos principais fatores ambientais que causam perda de eficiência desses sistemas, juntamente com irradiância, temperatura e sombreamento. Neste sentido, o presente trabalho busca verificar os efeitos da sujidade na eficiência dos módulos fotovoltaicos, por meio de coletas de dados, medições de parâmetros específicos, análise estatística e comparações de cenários de módulos sujos e limpos. Para a comprovação e quantificação da interferência da sujidade na eficiência de módulos fotovoltaicos são obtidos os parâmetros elétricos e ambientais capazes de caracterizá-los, são eles: Isc - Corrente de curto-circuito (A); Voc - Tensão de circuito aberto (V); G - Irradiância solar (W/m²); T - Temperatura do módulo (°C). A partir dos resultados pode-se observar que a intensidade da radiação solar tem maior influência sobre a corrente do módulo, enquanto que a temperatura afeta diretamente a tensão. Este trabalho comprovou que, no universo estudado, a sujidade diminuiu a eficiência dos módulos em até 3,2% para sujeira acumulada em períodos de 45 dias, e em até 18% para sujidades acumuladas por um período mais longo, de 3,5 anos. A caracterização da sujidade demonstrou que além de partículas minerais, há também matéria orgânica derivada de biofilmes, que dificulta a limpeza dos módulos pelos métodos naturais (chuvas e ventos). Com base na bibliografia e nos ensaios realizados, estima-se que a periodicidade de higienização não deva exceder 60 dias, assim os efeitos da sujidade são reduzidos significativamente.

Measurement uncertainty is an indication of the quality of a given measurement and ultimately translates into the confidence with which a decision can be made. In the context of PV, measurement uncertainties propagate into energy yield uncertainty, which in turn culminates into financial risk associated with an investment. This risk increases the cost of a PV installation. The aim of this thesis is to contribute towards the reduction of PV related measurement uncertainties. This is done in two ways. One is via developing and utilising more comprehensive methodologies for uncertainty propagation of complex measurands. The other is via more detailed estimates of the uncertainty contributors. In particular, the areas addressed in this thesis are the uncertainty estimation of the temperature coefficient measurements of modules; the uncertainty estimation of energy rating and module performance ratio measurements; and the uncertainties due to spectral effects on measurements performed with a flash solar simulator. The reported deviation in measurements of the temperature coefficients of P_MAX of modules is in the order of ±10% to ±15%. This is larger than the difference in the temperature coefficients of modules of the same type. The first step to improving the deviation between measurements is to estimate the uncertainty in a robust way. It was identified that there was no accepted approach of doing this. These measurements are strongly correlated, which complicates the uncertainty estimates. For the sake of simplicity, previously correlations have been avoided and conservative estimates used instead. In this work, uncertainties in both temperature and power and their correlations are estimated and propagated into the overall temperature coefficient uncertainty. Furthermore, temperature coefficients were calculated via weighing the measurements with their associated uncertainties. This was done for five different measurement setups that represent the majority of setups used worldwide. The approach was validated with measurement intercomparison of two modules measured on all systems. The approach reduced the overall uncertainty by half compared to the previous conservative estimates. It was demonstrated that uncertainties as low as 3% are achievable. The improved uncertainty estimates enabled the identification of a systematic effect due to a class B spectrum. This work culminated in the lowest reported measurement deviation of ±3.2% for module P_MAXtemperature coefficient measurements that was within the stated measurement uncertainties. The clear benefit of accounting for correlations was extended to measurements at different irradiance conditions and into the calculation of module performance ratio and energy rating. This was done via defining all the correlations between measurements and then propagating them with Monte Carlo simulations. The simulations are done with samples of a multivariate normal distribution with a variance-covariance matrix that corresponds to the estimated measurement correlations. It is demonstrated that both the energy rating and module performance ratio uncertainties strongly depend on the correlation estimates and that they cannot be conservatively overestimated. The module performance ratio uncertainty can be significantly lower than the measurement uncertainty at STC. This is because of the additional knowledge encoded into the selection of the underlying model used for calculating the energy rating. Therefore, the significance of the choice of model in the upcoming standard has been highlighted. It was confirmed that both bilinear interpolation and the proposed climatic datasets could be used for energy rating, but there are some areas that may need further investigation. An alternative way of improving uncertainty estimates and in turn reducing the associated uncertainty is via a more detailed characterisation of the uncertainty sources. A key uncertainty source is due to spectral effects in flash solar simulators. To better quantify this source, a complementary device was built to monitor the spectrum. The device is based on a matrix of photodiodes with commercially available interference filters situated on top and custom designed data acquisition electronics. This device is used in conjunction with the spectroradiometer to estimate the effects of flash-variation on the spectrum, the spectral temporal stability of the flash and spectral uniformity of the simulator and the attenuation masks used for altering the irradiance levels. It was demonstrated that the spectrum changes significantly during the flash and between flashes. While this effect is partially corrected for via the monitoring cell, it introduces additional uncertainty for non c-Si modules. This uncertainty is minimised by changes in the operational procedures. The spectral non-uniformity of the attenuation masks was shown to be significant, i.e. as large as 4%, in the NIR, prompting further investigation of the additional uncertainty for non c-Si modules. In this work, the methodology of estimating and propagating correlations in PV related measurements and the benefits of doing so are demonstrated. It is also highlighted that the uncertainty due to spectral effects goes beyond the uncertainty of spectroradiometer measurements. Finally, it is shown how they can be estimated with a complementary spectral monitor.

A presente Tese de Doutorado apresenta uma análise de diversos fatores que influenciam nos resultados da caracterização elétrica de módulos fotovoltaicos e na obtenção de seus principais parâmetros. A principal análise refere-se aos efeitos que ocorrem ao traçar a curva I-V (corrente versus tensão) de um módulo fotovoltaico decorrentes da rapidez e da direção da varredura (de Isc para Voc e vice-versa) utilizada na tensão de polarização necessária para traçar a curva I-V. Quando a caracterização elétrica é realizada com tempo de varredura reduzido, como por exemplo, em simuladores solares pulsados, há desvios significativos nos resultados, dependendo da tecnologia de fabricação do módulo fotovoltaico. Também é analisada a importância do fator de descasamento espectral no resultado da caracterização elétrica de módulos fotovoltaicos. Uma comparação entre os resultados dos valores dos coeficientes térmicos determinados com simulador solar (indoor) e sob iluminação natural (outdoor) é realizada, concluindo-se que são equivalentes dentro do intervalo de incerteza das medidas. Finalmente é apresentada uma comparação entre medidas realizadas sob iluminação natural e com simulador solar, levando-se em conta os fatores investigados na tese, isto é, os efeitos decorrentes da rapidez da varredura de tensão, da medida da temperatura do módulo e do descasamento espectral no momento da caracterização. / This doctoral thesis presents an analysis of several issues that influences the electrical characteristics of photovoltaic modules and its parameters. The main analysis is about sweep time effects that arise due to the speed and direction (Isc to Voc and vice versa) used to polarize the module in order to trace the I-V curve. A fast voltage sweep, as used in pulsed solar simulators, can cause discrepancies in the results of some photovoltaic module technologies. It is also analyzed the importance of the spectral mismatch factor in the characterization of photovoltaic devices. A comparison of indoor and outdoor measurements of thermal coefficients is performed and it is concluded that they are equivalent and the results are equivalent among the experimental uncertainties. Finally a comparison between indoor and outdoor measurements of photovoltaic modules is presented where it is discussed the issues studied in the thesis, i.e., sweep time effects, temperature measurement and spectral mismatch factor.

A presente Tese de Doutorado apresenta uma análise de diversos fatores que influenciam nos resultados da caracterização elétrica de módulos fotovoltaicos e na obtenção de seus principais parâmetros. A principal análise refere-se aos efeitos que ocorrem ao traçar a curva I-V (corrente versus tensão) de um módulo fotovoltaico decorrentes da rapidez e da direção da varredura (de Isc para Voc e vice-versa) utilizada na tensão de polarização necessária para traçar a curva I-V. Quando a caracterização elétrica é realizada com tempo de varredura reduzido, como por exemplo, em simuladores solares pulsados, há desvios significativos nos resultados, dependendo da tecnologia de fabricação do módulo fotovoltaico. Também é analisada a importância do fator de descasamento espectral no resultado da caracterização elétrica de módulos fotovoltaicos. Uma comparação entre os resultados dos valores dos coeficientes térmicos determinados com simulador solar (indoor) e sob iluminação natural (outdoor) é realizada, concluindo-se que são equivalentes dentro do intervalo de incerteza das medidas. Finalmente é apresentada uma comparação entre medidas realizadas sob iluminação natural e com simulador solar, levando-se em conta os fatores investigados na tese, isto é, os efeitos decorrentes da rapidez da varredura de tensão, da medida da temperatura do módulo e do descasamento espectral no momento da caracterização. / This doctoral thesis presents an analysis of several issues that influences the electrical characteristics of photovoltaic modules and its parameters. The main analysis is about sweep time effects that arise due to the speed and direction (Isc to Voc and vice versa) used to polarize the module in order to trace the I-V curve. A fast voltage sweep, as used in pulsed solar simulators, can cause discrepancies in the results of some photovoltaic module technologies. It is also analyzed the importance of the spectral mismatch factor in the characterization of photovoltaic devices. A comparison of indoor and outdoor measurements of thermal coefficients is performed and it is concluded that they are equivalent and the results are equivalent among the experimental uncertainties. Finally a comparison between indoor and outdoor measurements of photovoltaic modules is presented where it is discussed the issues studied in the thesis, i.e., sweep time effects, temperature measurement and spectral mismatch factor.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / CoordenaÃÃo de AperfeÃoamento de Pessoal de NÃvel Superior / This dissertation presents the combination of an electrical and thermal model to represent the characteristics of the photovoltaic module floating in water. Based on the proposed model a MATLAB / Simulink software simulation is made and validated with data obtained through a experiment performed. Two experiments were conducted in the UFC Alternative Energy Laboratory in order to validate the model proposed by the use of two distinct manufacturing photovoltaic modules, a monocrystalline produced by Azur Solar GmbH model TSM 160M and a polycrystalline produced by Solartec model KS20T. The model proposed was satisfactory compared the model results with measured data, which is irradiance, temperature front, rear and IV characteristic curve of the PV module. The irradiance is obtained by a pyranometer LP02 model Hukseflux manufactured by Thermal Sensor, temperatures were measured with temperature sensors type thermo EN 100 and the characteristic curves were obtained by tracer curve mini-KLA, manufactured by IngenieurbÃro. The monocrystalline module errors were lower than 4% for short-circuit current values, open circuit voltage and maximum power point. To reduce the error the electric model initially proposed was changed at the point of maximum power and were obtained errors lower than 2% for the short-circuit current values, open circuit voltage and maximum power point. The polycrystalline module showed errors lower than 10% for the short-circuit current values, open circuit voltage and maximum power point. The polycrystalline module floating in water performance was compared to the conventional use (installed on the ground), being recorded a cell temperature difference at any given time of day to 29 ÂC between the two applications; as a consequence, better efficiency was obtained floating on the water module with power gains of up to 17% compared to conventional usage. / Esta dissertaÃÃo apresenta a combinaÃÃo de um modelo elÃtrico e tÃrmico para representar as caracterÃsticas do mÃdulo fotovoltaico flutuante em Ãgua. A partir do modelo proposto à realizada simulaÃÃo no software MATLAB/Simulink e validado com dados obtidos atravÃs de experimento realizado. Foram realizados dois experimentos no LaboratÃrio de Energias Alternativas da UFC a fim de validar o modelo proposto atravÃs da utilizaÃÃo de dois mÃdulos fotovoltaicos de caracterÃstica de fabricaÃÃo distintas, um monocristalino da Azur Solar GmbH modelo TSM 160M e um policristalino da Solartec modelo KS20T. O modelo proposto mostrou-se satisfatÃrio quando comparado os resultados do modelo com os dados medidos, que sÃo irradiÃncia, temperatura frontal, posterior e curva caracterÃstica I-V do mÃdulo fotovoltaico. A irradiÃncia à obtida atravÃs do piranÃmetro modelo LP02 do fabricante Hukseflux Thermal Sensor, as temperaturas foram medidas com sensores de temperatura tipo termorresistÃncia PT 100 e a curvas caracterÃsticas foram obtidas atravÃs do traÃador de cuva mini-KLA, do fabricante IngenieurbÃro. O mÃdulo monocristalino apresentou erros inferiores a 4% para os valores de corrente de curto-circuito, tensÃo de circuito aberto e ponto de mÃxima potÃncia. Visando diminuir o erro alterou-se o modelo elÃtrico proposto inicialmente no ponto de mÃxima potÃncia e foram obtidos erros inferiores a 2% para os valores de corrente de curto-circuito, tensÃo de circuito aberto e ponto de mÃxima potÃncia. O mÃdulo policristalino apresentou erros inferiores a 10% para os valores de corrente de curto-circuito, tensÃo de circuito aberto e ponto de mÃxima potÃncia. Observou-se o rendimento do mÃdulo policristalino flutuante em Ãgua em relaÃÃo ao uso convencional (instalado sobre o solo), sendo registrada uma diferenÃa de temperatura da cÃlula em determinado horÃrio do dia de atà 29ÂC entre as duas aplicaÃÃes; como consequÃncia, obteve-se melhor eficiÃncia do mÃdulo flutuante em Ãgua com ganhos de potÃncia de atà 17% em relaÃÃo ao uso convencional.

A presente Tese de Doutorado apresenta uma análise de diversos fatores que influenciam nos resultados da caracterização elétrica de módulos fotovoltaicos e na obtenção de seus principais parâmetros. A principal análise refere-se aos efeitos que ocorrem ao traçar a curva I-V (corrente versus tensão) de um módulo fotovoltaico decorrentes da rapidez e da direção da varredura (de Isc para Voc e vice-versa) utilizada na tensão de polarização necessária para traçar a curva I-V. Quando a caracterização elétrica é realizada com tempo de varredura reduzido, como por exemplo, em simuladores solares pulsados, há desvios significativos nos resultados, dependendo da tecnologia de fabricação do módulo fotovoltaico. Também é analisada a importância do fator de descasamento espectral no resultado da caracterização elétrica de módulos fotovoltaicos. Uma comparação entre os resultados dos valores dos coeficientes térmicos determinados com simulador solar (indoor) e sob iluminação natural (outdoor) é realizada, concluindo-se que são equivalentes dentro do intervalo de incerteza das medidas. Finalmente é apresentada uma comparação entre medidas realizadas sob iluminação natural e com simulador solar, levando-se em conta os fatores investigados na tese, isto é, os efeitos decorrentes da rapidez da varredura de tensão, da medida da temperatura do módulo e do descasamento espectral no momento da caracterização. / This doctoral thesis presents an analysis of several issues that influences the electrical characteristics of photovoltaic modules and its parameters. The main analysis is about sweep time effects that arise due to the speed and direction (Isc to Voc and vice versa) used to polarize the module in order to trace the I-V curve. A fast voltage sweep, as used in pulsed solar simulators, can cause discrepancies in the results of some photovoltaic module technologies. It is also analyzed the importance of the spectral mismatch factor in the characterization of photovoltaic devices. A comparison of indoor and outdoor measurements of thermal coefficients is performed and it is concluded that they are equivalent and the results are equivalent among the experimental uncertainties. Finally a comparison between indoor and outdoor measurements of photovoltaic modules is presented where it is discussed the issues studied in the thesis, i.e., sweep time effects, temperature measurement and spectral mismatch factor.

<p>Thin-film solar cells based around the absorber material CuIn_1-xGa_xSe₂ (CIGS) are studied with respect to their stability characteristics, and different ways of modelling device operation are investigated. Two ways of modelling spatial inhomogeneities are detailed, one fully numerical and one hybrid model. In the numerical model, thin-film solar cells with randomized parameter variations are simulated showing how the voltage decreases with increasing material inhomogeneities.</p><p>With the hybrid model, an analytical model for the p-n junction action is used as a boundary condition to a numerical model of the steady state electrical conduction in the front contact layers. This also allows for input of inhomogeneous material parameters, but on a macroscopic scale. The simpler approach, compared to the numerical model, enables simulations of complete cells. Effects of material inhomogeneities, shunt defects and grid geometry are simulated.</p><p>The stability of CIGS solar cells with varying absorber thickness, varying buffer layer material and CIGS from two different deposition systems are subjected to damp heat treatment. During this accelerated ageing test the cells are monitored using characterization methods including J-V, QE, C-V and J(V)_T. The degradation studies show that the typical V_OC decrease experienced by CIGS cells subjected to damp heat is most likely an effect in the bulk of the absorber material.</p><p>When cells encapsulated with EVA are subjected to the same damp heat treatment, the effect on the voltage is considerably reduced. In this situation the EVA is saturated with moisture, representing a worst case scenario for a module in operation. Consequently, real-life modules will not suffer extensively from the V_OC degradation effect, common in unprotected CIGS devices.</p>

As ferramentas computacionais utilizadas em diferentes áreas de pesquisa têm como vantagem sobre análises e ensaios reais a possibilidade de analisar sistemas em diferentes condições de forma mais ágil e com menor consumo de tempo e recursos. A modelagem óptica de dispositivos fotovoltaicos é bastante difundida. Existem diferentes trabalhos na área, com diferentes escopos e graus de detalhamento, que permitem a análise e melhor compreensão das diferentes etapas da conversão da radiação em energia elétrica, expandindo as possibilidades de otimização. No presente trabalho foi desenvolvida, em uma etapa inicial, uma metodologia computacional para análise óptica de módulos fotovoltaicos, para então, em uma segunda etapa, serem realizados estudos do desempenho de diferentes materiais inseridos no conjunto de camadas que compõe os módulos, através da metodologia. O modelo óptico que embasa o método tem como foco os módulos de silício monocristalino. Esses módulos agregam de três a quatro camadas transparentes sobre as células fotovoltaicas. Ao incidir nesse conjunto de camadas radiação é submetida a diferentes eventos de extinção, como função do comprimento de onda da radiação e ângulo de incidência, que devem ser previstos em um modelo de forma a obter-se resultados válidos de transmissividade. A metodologia propõe a realização de uma análise aprofundada dos fenômenos ópticos que ocorrem mediante a incidência de radiação em um módulo fotovoltaico de modo a auxiliar na análise da adequação e desempenho de diferentes materiais ao sistema óptico formado. A otimização da transmissão de radiação em um módulo fotovoltaico tem uma influência direta e significativa sobre a eficiência de tais dispositivos, justificando sua importância. A validação do modelo foi realizada através da literatura, em partes, e apresentou coerência com os resultados de referência. Foram produzidos na segunda etapa estudos de desempenho de materiais ou propriedades isoladamente. No primeiro estudo foram analisados três materiais para aplicação como filme de passivação sobre a célula, sendo eles Si3N4, SiO2, e TiO2; o filme de Si3N4 apresentou o melhor desempenho. O segundo estudo, de avaliação da influência do índice de refração do encapsulante na transmissividade do sistema, demonstrou que a variação desse parâmetro tem muito pouca influência. No terceiro estudo foi analisado o potencial dos materiais PDMS e TiO2 como filmes anti-reflexo sobre vidro. O PDMS gerou melhores resultados de transmissividade. Por fim um estudo de desempenho de um conjunto de materiais frente à mudança do espectro incidente foi realizado. Foi utilizado até então o espectro de referência, que foi então comparado a um espectro médio de um dia de equinócio da cidade de Porto Alegre. O desempenho do sistema foi em torno de 3% inferior em incidência normal. / Computational tools raise the possibility of studying and understanding systems under different conditions in a faster and less resource and time consuming way. The optical modeling of photovoltaic devices is a very developed issue, and paperworks and projects in different scopes e levels of detail were produced, providing a better understanding of the different steps of converting light into electricity, expanding optimization possibilities. For this project a computational methodology was developed, as an initial step, for the optical assessment of the transmission of radiation in photovoltaic modules. In a second step, studies were performed using the method as a tool for analyzing the system formed by the layers covering the cells embedded in modules. The optical model describes monocristalline silicon modules, which are constituted by three to four layers covering the cell. Once it penetrates the set of layers, incident light suffers different extinction phenomena, which are predicted in this model in order to generate valid results. It’s a function of wavelength and incidence angle of the incoming radiation. The model presented aims to deeply analyse and understand the optical phenomena light undergoes through its way from the external environment to the interior of the cell, supporting the process of observing the performance and adequacy of different materials as the referred layers. Optimizing transmission of radiation in a photovoltaic device plays a main role in increasing the efficiency of the energy conversion process, which is why it’s so important. The model was validated by literature in parts, and showed coherence within reference results. Studies were produced in a second step of this work, using the method, concerning optical issues, for the thin film on top of the cell, the refractive index of the encapsulating material, and the optical effect of coating the outer glass surface. In the first study Si3N4, SiO2 and TiO2 were analyzed; the Si3N4 film produced the best results. The second study, concerning encapsulant’s refractive index, demonstrates this parameter has a very weak influence in the system’s transmission. The third one observed the performance of two materials, PDMS and TiO2, as AR coating,. The PDMS film produced a better effect. At last, the best performance set of layers was analyzed under a representative spectral distribution of an equinox day of the city of Porto Alegre, considering so far it was used the standard. The transmission suffered a slight decrease, around 3%.