abstract: This is a two part thesis: Part – I This part of the thesis involves automation of statistical risk analysis of photovoltaic (PV) power plants. Statistical risk analysis on the field observed defects/failures in the PV power plants is usually carried out using a combination of several manual methods which are often laborious, time consuming and prone to human errors. In order to mitigate these issues, an automated statistical risk analysis (FMECA) is necessary. The automation developed and presented in this project generates about 20 different reliability risk plots in about 3-4 minutes without the need of several manual labor hours traditionally spent for these analyses. The primary focus of this project is to automatically generate Risk Priority Number (RPN) for each defect/failure based on two Excel spreadsheets: Defect spreadsheet; Degradation rate spreadsheet. Automation involves two major programs – one to calculate Global RPN (Sum of Performance RPN and Safety RPN) and the other to find the correlation of defects with I-V parameters’ degradations. Based on the generated RPN and other reliability plots, warranty claims for material defect and degradation rate may be made by the system owners. Part – II This part of the thesis involves the evaluation of Module Level Power Electronics (MLPE) which are commercially available and used by the industry. Reliability evaluations of any product typically involve pre-characterizations, many different accelerated stress tests and post-characterizations. Due to time constraints, this part of the project was limited to only pre-characterizations of about 100 MLPE units commercially available from 5 different manufacturers. Pre-characterizations involve testing MLPE units for rated efficiency, CEC efficiency, power factor and Harmonics (Vthd (%) and Ithd (%)). The pre-characterization test results can be used to validate manufacturer claims and to evaluate the product for compliance certification test standards. Pre-characterization results were compared for all MLPE units individually for all tested parameters listed above. The accelerated stress tests are ongoing and are not presented in this thesis. Based on the pre-characterizations presented in this report and post-characterizations performed after the stress tests, the pass/fail and time-to-failure analyses can be carried out by future researchers. / Dissertation/Thesis / Masters Thesis Engineering 2015

The aim of the Thesis is theoretical clarification of the issues of photovoltaic power plants, their diagnostics, inspection and performance measurement, including negative impacts on their operation and subsequent application of theoretical knowledge during practical inspection and diagnostics of PV power plants. In its introductory part, the Thesis deals with design, manufacturing and development of PV cells and panels and describes other necessary elements and components, including their use in individual types of photovoltaic systems. Another part describes electric parameters of PV cells and panels, especially the parameters that can be found out by measurement of V-A characteristics and also the parameters affecting the shape of the V-A characteristics. The third part is focused on failures of photovoltaic systems, which include various defects of photovoltaic cells and panels, it also provides for adverse factors affecting operation of the entire system, associated not only with weather influences but also with the actual design of the photovoltaic system. The fourth part deals with possibilities of increasing the cost-effectiveness of electricity generation by PV power plants on the basis of practical experience of their operators. The subsequent part determines, on the basis of technical standards, procedures for PV power plant inspections, the procedures for measurement and diagnostics of PV power plants and also other prerequisites connected with inspections and measurements. This part includes also a description of requirements for measuring devices, most frequent measurement errors, adverse impacts affecting measurements and methods of assessment of the data measured. The last part of the Thesis is practical. At first it deals with verification of the impact of defects of PV modules on the shape of their V-A characteristics, then with execution of inspections and diagnostics of a particular PV power plant, evaluation of the data identified and measured, as well as with a proposal of optimisation measures to increase cost-efficiency of the operation of that particular PV power plant.

Solar energy market has been rapidly growing in Sweden over the past few years. Älvdalen municipality in central Sweden is investigating the possibility of installing a utility-scale solar power plant. In the present work, we investigate technical design and economic viability of a utility-scale solar power plant in Älvdalen. Several photovoltaics (PV) designs on a 6.6-hectar land are modeled and analyzed. The installation capacity depends on design parameters, such as inter-row spacing distance and orientation.PVsyst simulation tool is used to model several PV system configurations, consisting of both mono- and bifacial PV modules. An extensive sensitivity analysis is performed to get a deep understanding of different design parameters and their effects on performance and production yield of the plant.For PV systems consisting of monofacial PV panels, a set of parameters is investigated, namely, tilt angle of PV arrays, space between rows of the plant. It is observed that an optimized design requires a careful consideration of the two parameters, since they considerably affect the amount of self-shading (shading of PV rows on each other).The optimum design generates more than 5000 MWh electricity annually.Bifacial configurations are designed in two forms: tilted (south or south-east facing) and vertical (east-west oriented). Tiled bifacial systems are basically similar to the monofacial ones. A comparison between the two systems shows that the bifacial gain is between 3 % to 10 %, depending on the tilt angle, inter-row spacing, and PV array height above the ground. Electricity generation per surface area of the vertical east-west bifacial configuration is significantly lower compared to the others and therefore, it is only economically viable together with other land applications, such as agricultural usage.Economical evaluation indicates that for the optimum design the levelized cost of energy (LCOE) is 0.67 SEK/MWh and 0.72 SEK/MWh for monofacial and bifacial system, respectively. Such financial figures are subject to change, depending on the design and financial parameters.

O objetivo deste trabalho é modelar a arquitetura de uma usina solar fotovoltaica arrefecida intitulada UFVa, utilizando um protótipo de verificação. A metodologia se baseia na medição, verificação e análise dos dados de temperatura e produção de energia elétrica dos strings de teste (arrefecido) e comparação (não arrefecido), estudo do comportamento da alimentação de água do sistema de arrefecimento e o impacto das condições climáticas na operação do protótipo de UFVa. Por meio das análises dos dados constatou-se que, para o período entre as 09h00min e as 17h30min, os módulos PV do string de teste sempre operam com temperaturas inferiores aos módulos PV do string de comparação. Durante o período de testes, no qual a temperatura dos módulos PV do string de comparação operou acima de 55,0°C, as temperaturas médias e máximas registradas nos módulos PV do string de teste foram inferiores a 37,0 °C, operando sempre abaixo da temperatura nominal de operação da célula (NOCT). A produção de energia elétrica no string de teste superou a do string de comparação em 3,0kWh/dia. Portanto, o sistema de arrefecimento reduz a temperatura de operação dos módulos PV, principalmente no período de máxima geração elétrica, que corresponde ao período das 11h00min às 15h00min, proporcionando ganhos médios de rendimento de 5,9% na produção de energia, 10,3% na potência e 5,4% no FC. / In this work we use a verification prototype to model the architecture of a solar photovoltaic power plant equipped with a cooling system. The power plant we model is called UFVa. The methodology is based on the measurement, verification, and data analysis of temperature, electricity generation, test strings (cooled) and comparison strings (not cooled), along with a study of the water feeding behavior of the cooling system, and the impact of climatic conditions in the UFVa prototype operation. By analyzing the data we observed that, for the period between 09:00am and 5:30pm, the PV modules of the test string operate at temperatures below those of the PV modules of the comparison string. During the tests, in which the temperature of the PV modules of the comparison string operated above 55.0°C, the average and the maximum temperatures recorded in the PV modules of the testing string lied below 37.0°C, operating below the NOCT. Regarding the generation of electricity, the test string generated 3.0 kWh/day more than the comparison string. Hence, the cooling system decreases the operating temperature of the PV modules, particularly during the maximum power generation period which is from 11am to 3pm. This leads to efficiency average gains of up to 5.9% in the generation of electricity, 10.3% in the power, and 5.3% in the PR and PF.

O objetivo deste trabalho é modelar a arquitetura de uma usina solar fotovoltaica arrefecida intitulada UFVa, utilizando um protótipo de verificação. A metodologia se baseia na medição, verificação e análise dos dados de temperatura e produção de energia elétrica dos strings de teste (arrefecido) e comparação (não arrefecido), estudo do comportamento da alimentação de água do sistema de arrefecimento e o impacto das condições climáticas na operação do protótipo de UFVa. Por meio das análises dos dados constatou-se que, para o período entre as 09h00min e as 17h30min, os módulos PV do string de teste sempre operam com temperaturas inferiores aos módulos PV do string de comparação. Durante o período de testes, no qual a temperatura dos módulos PV do string de comparação operou acima de 55,0°C, as temperaturas médias e máximas registradas nos módulos PV do string de teste foram inferiores a 37,0 °C, operando sempre abaixo da temperatura nominal de operação da célula (NOCT). A produção de energia elétrica no string de teste superou a do string de comparação em 3,0kWh/dia. Portanto, o sistema de arrefecimento reduz a temperatura de operação dos módulos PV, principalmente no período de máxima geração elétrica, que corresponde ao período das 11h00min às 15h00min, proporcionando ganhos médios de rendimento de 5,9% na produção de energia, 10,3% na potência e 5,4% no FC. / In this work we use a verification prototype to model the architecture of a solar photovoltaic power plant equipped with a cooling system. The power plant we model is called UFVa. The methodology is based on the measurement, verification, and data analysis of temperature, electricity generation, test strings (cooled) and comparison strings (not cooled), along with a study of the water feeding behavior of the cooling system, and the impact of climatic conditions in the UFVa prototype operation. By analyzing the data we observed that, for the period between 09:00am and 5:30pm, the PV modules of the test string operate at temperatures below those of the PV modules of the comparison string. During the tests, in which the temperature of the PV modules of the comparison string operated above 55.0°C, the average and the maximum temperatures recorded in the PV modules of the testing string lied below 37.0°C, operating below the NOCT. Regarding the generation of electricity, the test string generated 3.0 kWh/day more than the comparison string. Hence, the cooling system decreases the operating temperature of the PV modules, particularly during the maximum power generation period which is from 11am to 3pm. This leads to efficiency average gains of up to 5.9% in the generation of electricity, 10.3% in the power, and 5.3% in the PR and PF.

Renewable energy resources, especially photovoltaics, have experienced enormous boom all over the world in the past few years. It was completely the same in Czech Republic where you would not find anybody without his own opinion regarding PV business. Installation of PV power plants has become very attractive business, with very significant role in 2011 in Czech Republic. At this time, this solar boom has found its "home" in other European countries, particularly in Eastern Europe. The post of the new Eastern Europe's "powerhouse" can defend even Romania, that's the cause I have chosen this country as the subject of this thesis. The aim of this thesis is to create a business plan for PV power plant and evaluate the investment opportunity of its installation in Romania. And then by means of a sensitivity analysis find out the impact of external factors that can significantly affect the profitability of the project.

Main purpose of the thesis is to create proposal of the photovoltaic hybrid system for commercial building in accordance with applicable rules for energy savings program. The introductory part of the thesis describes the rules regarding the photovoltaic system parts. The next part of the thesis describes the available technical solution for realization of the photovoltaic system design and the possibilities of electric energy accumulation in these systems and how to deal with power overflows using the power flow controller and what is the negative impacts on the distribution network when switching the connected load. In the next part the design of the PV system is carried out according to the valid assumptions described in the theoretical part of the thesis. Verification of power flow controller and measurement results in UEEN laboratories. The last part of the thesis is an evaluation of the economic part of the proposed system.