https://repositorio.ufpb.br/jspui/handle/tede/7763 PPGER Fri, 14 Aug 2026 11:18:49 GMT 2026-08-14T11:18:49Z https://repositorio.ufpb.br/jspui/handle/123456789/38563 Título: Filtro óptico de radiação para células solares utilizando filmes finos multicamadas de óxido de índio e estanho e prata Autor(es): França, Lucas Medeiros de Orientador: Gomes, Kelly Cristiane Abstract: The increase in global energy demand has led to massive consumption of fossil fuels, intensifying climate change. Electricity accounts for one-third of this demand – more than half concentrated in buildings, with 50% of this consumption for thermal comfort systems. To supply electricity generation in a clean and sustainable way, several alternative and renewable sources have emerged, with solar energy standing out as the most promising on a large scale. However, this technology still faces some challenges and is close to the point of maximum efficiency of the main material that makes up these photovoltaic conversion devices, silicon. However, other materials are emerging and new photovoltaic cells are being developed. Furthermore, current solar cell materials are not capable of absorbing the complete solar electromagnetic spectrum for energy generation, with a large portion of the energy being absorbed as heat – generating warming, loss of efficiency, and degradation. Therefore, this work proposes optical radiation filters with the aim of transmitting to photovoltaic cells only the radiation range suitable for the photoelectric effect and reflecting the undesirable radiation range. The optical filter is a thin multilayer film composed of alternating indium tin oxide (ITO) and silver (Ag), where the optical properties were simulated and optimized via software (OpenFilters) with respect to the number of layers (3 and 5) and thicknesses. The films with the best performance were manufactured by magnetron sputtering and annealed at 350 °C for 1 hour in a muffle furnace. Optical characterizations were performed by UV-Vis spectrophotometry and heat blocking tests with a thermographic camera in an outdoor environment after exposure to solar radiation for 1 hour. Simulations demonstrate that the film with the best results for the desired regions of the solar spectrum is ITO/Ag/ITO/Ag/ITO (IAIAI) with 35/5/80/5/35 nm (T = 83.65% in the visible spectrum and R = 87.29% from 1100 to 2500 nm). However, it was not possible to manufacture it satisfactorily, resulting in poor transmittance and thermal blocking results. The IAIAI10 film showed good simulation results (T = 66.41% in the visible spectrum and R = 93.50% from 1100 to 2500 nm) and spectrophotometry results (T = 66.17% in the visible spectrum and T = 5.65% from 1100 to 2500 nm), as well as satisfactory thermal blocking (an increase of 4 °C after 1 hour, versus increases of 8 to 22 °C in other samples). In both films, the heat treatment was not satisfactory. Thus, this work produced optical radiation filters that show potential for use in solar cells to reduce the operating temperature and, consequently, mitigate efficiency losses due to heating during the energy generation process. Editor: Universidade Federal da Paraíba Tipo: Dissertação Wed, 25 Feb 2026 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/38563 2026-02-25T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/38556 Título: Validação, análise e mitigação de falhas em linhas de transmissão de energia elétrica usando ferramentas de qualidade e confiabilidade Autor(es): Souza, Karla Paloma Belarmino de Orientador: Peruchi, Rogério Santana Abstract: Transmission lines (TL) are essential components of the electric power system due to their function of transmitting generation over short and long distances. Historical data from the Brazilian National Electric System Operator have shown that TL are the assets with the highest incidence of disturbances, as they are constantly exposed to hostile environments, adverse weather conditions, and factors that are difficult to control. Recurrent disturbances result in unplanned outages that directly affect system reliability and power supply quality, and incur financial penalties for transmission companies. The objective of this research is to identify and highlight the main failures that cause TL outages and to propose actions that can minimize or eliminate the risks of failures and their effects. For this purpose, the study was divided into three articles. The first article consists of a systematic literature review aimed at identifying and synthesizing existing scientific knowledge on the application of Attribute Agreement Analysis (AAA), Fault Tree Analysis (FTA), and Failure Modes and Effects Analysis (FMEA) in electric power systems. In the second article, AAA was applied, based on expert opinions and contributions from artificial intelligence (AI), as a validation tool for the causes of forced outages in TL. In the third article, probabilistic fault trees were developed to highlight the combinations of failures that may lead to undesirable TL outages. Based on the fault tree, an analysis of the causes and effects of each identified failure mode was performed, as well as their prioritization according to the associated risk, calculated based on severity, occurrence, and detection indices. Finally, actions were recommended to mitigate or eliminate the risks that may cause TL outages. The results showed that FTA and FMEA are widely studied and consolidated techniques in electric power systems, unlike AAA, which has been little explored in this context. The application of AAA to TL highlighted weaknesses in expert opinions due to divergent views and subjective interpretations, as well as an increase in the robustness of the analysis results due to the use of artificial intelligence. Through the application of FTA and FMEA, it was possible to verify that the main causes of transmission line outages are lightning strikes, wildfires, and strong winds; however, those that present the greatest risk to the operation of TL and the electric power system are outages caused by wildfires, strong winds, vegetation, and tower collapse. This research can directly contribute to the prioritization of preventive or corrective actions with greater impact on the prevention of unplanned TL outages, assisting transmission companies in resource management, increasing the reliability of transmission line operation and maintenance, and consequently improving the quality of power supply. Editor: Universidade Federal da Paraíba Tipo: Dissertação Fri, 30 Jan 2026 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/38556 2026-01-30T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/38266 Título: Avaliação técnico-econômica-ambiental de um sistema de geração híbrido com auxílio de baterias novas e de segunda vida Autor(es): Almeida, Katarina Ferreira Trigueiro de Orientador: Reis, Raphael Leite de Andrade Abstract: Renewable energy sources are intermittent and require flexibility solutions, such as energy storage systems (ESS). Among these, battery energy storage systems (BESS) stand out for their fast response, low operating costs, and potential for applications such as peak shaving and frequency regulation. However, they face limitations such as high upfront costs, reduced lifespan, and degradation due to charge and discharge cycles. In this context, second-life batteries (SLBs) emerge as a promising alternative. This study evaluates the technical, economic, and environmental feasibility of hybrid solar and wind systems using both new and second-life batteries, based on real data from the municipality of Tacaratu (PE), with the aim of meeting residential demand during peak hours. The analysis considered meteorological data, consumption profiles, commercial technologies, and scenarios of installed capacity variation. According to the results, batteries, especially new ones, can reduce grid dependence by up to 30%. SLBs, while showing slightly lower performance, offer lower costs and reduced environmental impact, even though they require a larger number of units to compensate for their reduced capacity. Despite this, almost all the analyzed scenarios showed financial infeasibility, with a negative Net Present Value (NPV) and an Internal Rate of Return (IRR) below expectations, even with variations in the Minimum Attractive Rate of Return (MARR). The only scenarios that proved to be financially viable were those with 25% of the expected initial capacity and only one renewable source; purely battery-based scenarios showed no viability at all. This highlights the need for regulatory reforms that recognize the services provided by ESS, such as power supply, energy reserve, and ancillary services. Proposed measures include the definition of storage agents, tariff adjustments, participation in capacity auctions, and incentives for research and development. The study reinforces the strategic role of batteries in Brazil’s energy transition, especially when integrated with renewable sources. The adoption of SLBs may accelerate their economic and environmental viability, but it depends on public policies that value the flexibility services provided to the power system. Editor: Universidade Federal da Paraíba Tipo: Dissertação Thu, 31 Jul 2025 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/38266 2025-07-31T00:00:00Z https://repositorio.ufpb.br/jspui/handle/123456789/38246 Título: Impactos ambientais e socioeconômicos da implantação de uma usina solar fotovoltaica no estado da Paraíba Autor(es): Bernardo, Maria da Conceição Gomes Orientador: Reis, Raphael Leite de Andrade Abstract: The study addresses the installation of a solar power generation and distribution plant in the municipality of Juazeirinho, Paraíba, Brazil. The research aims to identify and analyze the environmental and social impacts resulting from the installation process of a 1 MW photovoltaic plant, from the initial stages to project completion. The study seeks to quantify and qualify these impacts, proposing mitigation strategies and material reuse practices. Legal and environmental aspects are highlighted, emphasizing the role of the National Environment Council (CONAMA) and the need for Simplified Environmental Licensing (LAS) for such enterprises. The study area was analyzed using simplified Environmental Impact Assessment (EIA) tools, identifying influence zones, installation methods, mitigation measures, and environmental control programs. The research was motivated by the lack of environmental licensing in small-scale solar enterprises in the semi-arid region of Paraíba. The results indicated impacts of moderate to high magnitude, mainly vegetation suppression, soil compaction, and landscape alteration. It is recommended to adopt waste reuse practices and implement continuous environmental monitoring programs to reduce negative effects and strengthen the sustainability of the solar energy sector. It is concluded that the practical and systematic application of EIA tools in small-scale projects represents a relevant contribution to the improvement of environmental assessment and management practices at the local scale. Editor: Universidade Federal da Paraíba Tipo: Dissertação Fri, 01 Aug 2025 00:00:00 GMT https://repositorio.ufpb.br/jspui/handle/123456789/38246 2025-08-01T00:00:00Z