Turbina Axial para Condições de Ultra-Baixa Queda

As turbinas axiais convencionais são turbinas que operam em condições de baixa-queda, ou seja, alturas de queda entre 70 e até 5 metros. São máquinas que operam com baixas alturas de queda e altas vazões. Para alturas de queda abaixo de 5,0 metros, ainda estão sendo desenvolvidas máquinas para operação dentro desse parâmetro. Máquinas desse porte geram viabilidade econômica e devido à facilidade de sua manutenção e o não emprego de grandes obras civis, podendo ser instaladas em pequenos canais em propriedades rurais e comunidades. Um termo de cooperação científica entre Canadá e Brasil favoreceu para que um modelo de turbina desenvolvido por uma instituição canadense e fosse ensaiada nas dependências da Universidade Federal de Itajubá fosse realizado.Palavras-chave: turbina axial, ultra-baixa queda, ensaio de eficiência mecânica

Use of floating PV plants for coordinated operation with hydropower plants: Case study of the hydroelectric plants of the Sao Francisco River basin

[EN] In recent years, the Brazilian electricity sector has seen a considerable reduction in hydroelectric production and an increase in dependence on the complementation of thermoelectric power plants to meet the energy demand. This issue has led to an increase in greenhouse gas emissions, which has intensified climate change and modified rainfall regimes in several regions of the country, as well as increased the cost of energy. The use of floating PV plants in coordinated operation with hydroelectric plants can establish a mutual compensation between these sources and replace a large portion of the energy that comes from thermal sources, thereby reducing the dependence on thermoelectric energy for hydropower complementation. Thus, this paper presents a procedure for technically and economically sizing floating PV plants for coordinated operation with hydroelectric plants. A case study focused on the hydroelectric plants of the Sao Francisco River basin, where there has been intense droughts and increased dependence on thermoelectric energy for hydropower complementation. The results of the optimized design show that a PV panel tilt of approximately 3 degrees can generate energy at the lowest cost (from R $298.00/MWh to R$312.00/MWh, depending on the geographical location of the FLOATING PV platform on the reservoir). From an energy perspective, the average energy gain generated by the hydroelectric plant after adding the floating PV generation was 76%, whereas the capacity factor increased by 17.3% on average. In terms of equivalent inflow, the PV source has a seasonal profile that compliments the natural inflow of the river. Overall, the proposed coordinated operation could replace much of the thermoelectric generation in Brazil.The authors would like to thank the Brazilian National Council for Scientific and Technological Development (Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq; in Portuguese) for granting a productivity in research scholarship to Prof. Regina Mambeli Barros (PQ2, Process number: 301986/2015-0) and Prof. Geraldo Lúcio Tiago Filho and to the Brazilian Coordination for the Improvement of Higher Education Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Capes; in Portuguese) for granting the Master of Science scholarship to Naidion Motta Silvério and the Doctorate scholarship to Ivan Felipe da Silva dos Santos.Silverio, N.; Barros, R.; Tiago Filho, GL.; Redón-Santafé, M.; Silva Dos Santos, IF.; De Mello Valerio, VE. (2018). Use of floating PV plants for coordinated operation with hydropower plants: Case study of the hydroelectric plants of the Sao Francisco River basin. Energy Conversion and Management. 171:339-349. https://doi.org/10.1016/j.enconman.2018.05.095S33934917

Evaluation of wind potential in Caraguatatuba, northern coast of Sao Paulo

This study aims to assess the potential for wind power generation in the town of Caraguatatuba – Sao Paulo North Coast - Brazil. The statistical analysis of wind speed will contribute to this evaluation. Data of wind speed from 2004 to 2013, corresponding to the meteorological station Caraguatatuba (code 32521) Sinda/INPE system were used. Weibull distributions for the four seasons were analyzed, and their shape and scale parameters for the wind speed data, from which an extrapolation of the vertical profile of the wind to height of 100m was performed. It was found that the average power of the wind speed is favorable to the installation of wind turbines in all seasons

Estudo do potencial de geração de energia elétrica a partir do biogás de digestão anaeróbia de resíduos alimentares

In order to find sustainable ways of allocating organic waste, it is currently sought to use biological processes for treatment, being possible to use their derivatives as energy source and fertilizer. The article aims to analyze the results of a research that evaluated the energy potential of the biogas produced from the anaerobic biodigestion of the food residue produced by the restaurant “Sem Nome” in the municipality of Itajubá – MG. A pilot project was built, consisting of three PET bottles, which served as reactors, in addition to other objects such as gas valve, high pressure hose and temperature control. The production of CH4, CO, CO2, O2, H2S, Temperature and Pressure was monitored, as well as physical and chemical analyzes, which evaluated parameters such as ST, STF, SV, BOD, COD and pH. The concentration of CH4 in the biogas, as well as the energy potential, was theoretically estimated, due to the shortcoming in biodigestion system such as constant temperature drops and the presence of ruptures in the reactors, causing atmospheric gas infiltration. Therefore, assuming favorable conditions for the realization of anaerobic biodigestion and based on data provided by the literatur, CH4 production was estimated as well as the restaurant's energy potential, giving 65.65 L / day of CH4 during the week and 87.54 L / day on weekends and public holidays, making available a monthly 6,569.86 kWh of energy. With this data, it was possible to confirm the efficiency of methanization as a sustainable system for the disposal of organic waste, as well as to assist in the generation of electric energy.A fim de encontrar maneiras sustentáveis de destinar os resíduos orgânicos, busca-se atualmente utilizar-se de processos biológicos para tratamento, sendo possível utilizar seus derivados como fonte de energia e adubo. O artigo tem como objetivo analisar os dados de uma pesquisa a qual avaliou o potencial energético do biogás produzido a partir da biodigestão anaeróbia do resíduo alimentar produzido pelo restaurante Sem Nome no município de Itajubá – MG. Foi construído um projeto piloto, constituído por três garrafas PET´s, as quais serviram como reatores, além de outros objetos como válvula de gás, mangueira de alta pressão e controle de temperatura. Foi monitorado a produção de CH4, CO, CO2, O2, H2S, Temperatura e Pressão, além da realização de análises físicas e químicas as quais avaliaram os parâmetros como ST, STF, SV, DBO, DQO e pH. A concentração de CH4 no biogás, assim como o potencial energético, foram estimados teoricamente, devido a falhas no sistema de biodigestão como quedas constantes de temperatura e presença de rupturas nos reatores, causando infiltração de gás atmosférico. Portando, considerando condições favoráveis para realização da biodigestão anaeróbia, e com base em dados fornecidos pela literatura, estimou-se a produção de CH4, assim como o potencial energético do restaurante, conferindo 65,65 L/dia de CH4 durante a semana e 87,54 L/dia nos fins de semanas e feriados, disponibilizando mensalmente 6.569,86 kWh de energia. Com esses dados, foi possível confirmar a eficiência da metanização como um sistema sustentável de destinação dos resíduos orgânicos, além de auxiliar na geração de energia elétrica.Con el fin de encontrar formas sostenibles para destinar los residuos orgánicos, se busca actualmente emplear procesos biológicos para su tratamiento, siendo posible utilizar sus derivados como fuente de energía y abono. El artículo tiene como objetivo analizar los datos de una investigación en la que se que evaluó el potencial energético del biogás producido a partir de la biodigestión anaeróbica del residuo alimentario producido por el restaurante “Sem Nome” en el municipio de Itajubá - MG. Se construyó un proyecto piloto, constituido por tres botellas PET’s, las que sirvieron como reactores, además de otros objetos como válvula de gas, manguera de alta presión y control de temperatura. Se ha monitoreado la producción de CH4, CO, CO2, O2, H2S, Temperatura y Presión, además de la realización de análisis físicos y químicos que evaluaron parámetros como ST, STF, SV, DBO, DQO y pH. La concentración de CH4 en el biogás, como potencial energético, fue estimada teóricamente, debido a fallas en el sistema de biodigestión, como variaciones constantes de temperatura y la presencia de rupturas en el reactor, causando infiltración de gas atmosférico. Por lo tanto, considerando las condiciones favorables para la realización de la biodigestión anaeróbica, y sobre la base de datos proporcionados por la literatura, se estimó la producción de CH4, así como el potencial energético del restaurante, otorgando 65,65 L / día de CH4 durante la semana y 87 , 54 L / día en los fines de semanas y feriados, ofreciendo mensualmente 6.569,86 kWh de energía. Con estos datos, fue posible confirmar la eficiencia de la metanización como un sistema sostenible de destino de los residuos orgánicos, además de auxiliar en la generación de energía eléctrica

Use of Balanced Scorecard (BSC) Performance Indicators for Small-Scale Hydropower Project Attractiveness Analysis

Small-scale hydropower plants (SHP) have been losing competitiveness compared to other renewable sources in the global electricity matrix due to technical, environmental, regulatory, and economic issues. In this context, and to contribute to the development and strengthening of SHP’s integration into the country’s electricity matrix, this study proposes the Balanced Scorecard (BSC) as a strategic evaluation tool for SHP projects from the prospecting phase to the pre-implementation phase, taking into account financial and non-financial performance indicators. This study aims to structure a strategic map of the SHP source composed of economic, socio-environmental, institutional, and technical perspectives, adapted to the four perspectives of the BSC, with the required performance indicators for the strategic evaluation of SHP. The development of a computer program allowed data visualization from eight case studies focusing on indicators or perspectives that jeopardize the project’s strategic viability. The results showed that (i) the adaptation of the BSC methodology for the strategic evaluation of SHP feasibility proved effective and (ii) the developed computer program demonstrated robustness and effectiveness in analyzing SHP, even in different stages of development and with different technical and environmental characteristics. Finally, the strategic evaluation of SHP feasibility is an effective tool in assisting decision makers, indicating the positive aspects and weaknesses of the project under evaluation and providing a better understanding of the asset and the areas of development that deserve greater attention to improve its performance