The hydrogen society is a term that have received world notoriety. This is due to increasing on c... more The hydrogen society is a term that have received world notoriety. This is due to increasing on costs to obtain fossil fuels and the emission of many pollutants to atmosphere, mainly greenhouse gases. A portion of climates changes is directly related with this emissions, causing serious damages on human survival. The hydrogen is called the future fuel, this is due its clean combustion, that no emission pollutants to atmosphere. A enough clean option to obtain hydrogen is the utilization of renewable sources. This article reviews the forms to production, storage, distribution and utilization of hydrogen like as energy carrier, inserted on context of utilization of two renewable sources, the solar and eolian, for production of electrolytic hydrogen.
O presente estudo apresenta uma analise sobre a seguranca na instalacao de sistemas fotovoltaicos... more O presente estudo apresenta uma analise sobre a seguranca na instalacao de sistemas fotovoltaicos (FV) em aeroportos, inicialmente apresentando os principais aeroportos que ja possuem sistemas instalados no mundo e os estudos ja feitos para implementacao no Brasil. Em seguida se faz uma analise em relacao a seguranca para as operacoes aeroportuarias, bem como as medidas de se mitigar os riscos. O estudo tem como objetivo auxiliar aos interessados em implementar sistemas FV em aeroportos, orientando quanto a localizacao, direcionamento dos paineis e seguranca dos componentes do sistema.
Este estudo do tipo qualitativo descritivo examina como é que a Alfabetização Energética (AE) est... more Este estudo do tipo qualitativo descritivo examina como é que a Alfabetização Energética (AE) está se constituindo ao nível internacional como uma componente educacional integrada no contexto escolar. Um levantamento de 17 conceitos nas disciplinas de Ciências Naturais, Física, Biologia, Química, Geografia e História, nos programas curriculares de África do Sul, Brasil, Índia e Portugal em 10 anos de ensino foi realizado. Os resultados indicam que a taxa de cobertura dos conceitos é de 30% para Africa do Sul, 23% para Portugal, 18% para Brasil e 11% para India. A concentração dos conceitos ocorre nas disciplinas de Ciências Naturais para África do Sul (67%), Brasil (50%) e Índia (61%) enquanto para Portugal concentra-se na disciplina de Química-Física com 73%. Portugal revela uma evolução de integração de conceitos superior aos outros países o que pode fertilizar para uma melhor promoção de Eficiência Energética (EE) e consciência ambiental. Quanto à interdisciplinaridade, África do...
In this paper an innovative hybrid model of time series prediction based on the combination of tw... more In this paper an innovative hybrid model of time series prediction based on the combination of two functions (linear and nonlinear) of the Holt-Winters and Artificial Neural Networks models is presented. This model is applied in wind speed in northeastern Brazil, and was able to perform short and long term forecasts with good accuracy. We highlight the efficiency of the proposed model in providing perfect adjustments to the data observed, being this affirmative according to the low values found in the statistical analysis of errors, for example, with percentage error of approximately 5.0%, and also with the value of the Nash-Sutcliffe coefficient of efficiency of approximately 0.96. These results were important for the accuracy of the data, so that they could follow the profile of the observed time series, mainly revealing greater similarities of maximum and minimum values between both series, thus showing the capacity of the model to represent characteristics of local seasonality. ...
Anais do Congresso Brasileiro de Automática 2020, 2020
Neste trabalho são apresentadas a modelagem e controle de um sistema de dessalinização por osmose... more Neste trabalho são apresentadas a modelagem e controle de um sistema de dessalinização por osmose reversa. As entradas do sistema são as válvulas de bypass e da água de concentrado. As saídas do sistema são o fluxo da água de produto e a pressão de entrada do sistema. O modelo não linear obtido é linearizado e para o ponto de operação considerado um controlador por alocação de pólos com ação integral é projetado. Resultados preliminares são promissores, com bons resultados para rastreamento de referência e rejeição de distúrbios.
Solar energy is one of the main renewable energy sources capable of contributing to global energy... more Solar energy is one of the main renewable energy sources capable of contributing to global energy demand. However, the solar resource is intermittent, making its integration into the electrical system a difficult task. Here, we present and compare two machine learning techniques, deep learning (DL) and support vector regression (SVR), to verify their behavior for solar forecasting. Our testing from Spain showed that the mean absolute percentage error for predictions using DL and SVR is 7.9% and 8.52%, respectively. The DL achieved the best results for solar energy forecast, but it is worth mentioning that the SVR also obtained satisfactory results.
New technologies are coming to improve the use of power for the consumers in a bigger time from p... more New technologies are coming to improve the use of power for the consumers in a bigger time from photovoltaic source. This paper works arrangement with two types of technology of energy storage: Battery and electrolyzer-fuel cell set and three types of photovoltaic use: stand-alone, hybrid and connected to the grid.
The increasing energy demand is a global concern, directly associated with indicators of greenhou... more The increasing energy demand is a global concern, directly associated with indicators of greenhouse gases and air pollution. These, in turn, are directly related to the physical, social and economic aspects of cities. One way to minimize such impacts is to diversify the energy matrix with renewable sources. On the other hand, the use of wind and solar plants are susceptible to multiple conflicts, due to urban aesthetics, technology scale or directionality of the energy flow across individual property limits. Considering that the urban form directly impacts the energy demand and the existence of conflicts arising from the use of renewable sources, the integration between urban and energy planning plays an important role in mitigating the risks associated with the growth of renewable generation. With such motivation, we propose a comparative analysis of the main tools of urban and / or energy planning through a systematic review of the literature. The methodology of the literature rev...
O presente artigo tem como objetivo analisar a viabilidade do uso de paineis fotovoltaicos (FV) e... more O presente artigo tem como objetivo analisar a viabilidade do uso de paineis fotovoltaicos (FV) em duas Estacoes Elevatorias de Agua (E.E.A.),em Fortaleza e em Cascavel, no Estado do Ceara.A planta FV faz uso do mecanismo de compensacao, onde a eletricidade gerada pelos modulos FV e injetada na rede da concessionaria local e o valor descontado na conta de energia eletrica.O desenvolvimento e analise do projeto e realizado com auxilio do software de analise de projetos de energia limpa RETScreen. Por meio desse programa sao realizados os estudos sobre producao de eletricidade, custos do ciclo de vida e viabilidade financeira do projeto. Para a estimativa dos custos de implantacao do projeto sao considerados tres aspectos: custo de aquisicao de modulos FV, infraestrutura/interligacao com a rede e demais custos de implantacao. O projeto em estudo tem um custo total estimado de R$ 11.240.442,51 levando em consideracao que a capacidade instalada do sistema e de 1793 kWp. O retorno de cap...
In the present paper a statistical analysis of the wind speed in Ceara state, Northeast Brazilian... more In the present paper a statistical analysis of the wind speed in Ceara state, Northeast Brazilian, is made aiming to places whose wind energy potential can be used to electricity production. The best periods for wind energy use are shown; wind speeds from different sites are compared. Wind speed data measured at 70 meters height in the state for the 2005 show that the best wind speed values are found in the diurnal period. In the coastal area, sites with average wind speeds higher than 10 m/s are found, as Acarau and Barroquinha. On the mountains, sites with average wind speeds higher than 8 m/s are found, as Ubajara. Shape factor values of the Weibull distribution for sites in the coast in the dry period are in agreement with those found in the literature.
Floating photovoltaic (FPV) plants in reservoirs can contribute to reduce water evaporation, incr... more Floating photovoltaic (FPV) plants in reservoirs can contribute to reduce water evaporation, increase power generation efficiency, due to the cooling process, and reduce competitiveness in land use. Based on this motivation, we propose a new methodology for sizing FPV plants in dams of semi-arid regions using the flood duration curve. The methodology innovations are no use of commercial software, the possibility of choosing the reliability level, the application in reservoirs of semi-arid areas of the world, and the use of a graphic analysis of the reservoir hydrological behavior. The case studies in the Brazilian and Australian semi-arid consider two scenarios: high reliability level (90%, scenario 1) and low reliability level (70%, scenario 2). The reliability level is linked to the electricity production; the evaporation reduction is proportional to the FPV plant area.
The present paper describes the design, development, implementation and validation of an Internet... more The present paper describes the design, development, implementation and validation of an Internet of Things (IoT) network with sensors signal conditioning circuits for monitoring decentralized photovoltaic (PV) plants. The system intends to reduce costs of commercial dataloggers and sensing modules which require control and data storage using proprietary software. We applied our IoT monitoring network in three PV plants installed in Fortaleza and Maracanaú cities, Brazil, and in Cologne, Germany. The applied embedded solutions (namely, ESP 8266 and ESP 32) are based on free software and hardware and communicate with a Cloud server via Wi-Fi. A website, called Web Monitor, was developed in PHP for online and real-time data consultation in form of charts. The main objective of the proposal is to measure PV module temperature, providing data for the analysis of PV module’s efficiency and for fault detection in case of PV cells overheating. Solar irradiance, ambient temperature, relative air humidity and wind speed are also monitored, getting more data to analyze the effect of meteorological parameters on the PV module’s performance. The proposed system was designed in compliance with IEC 61724:1998 standard and the obtained charts are discussed in the results section considering different periods of the year. Finally, we validate the proposed temperature conditioning system with a commercial piece of equipment and a correlation of 0.9999 was achieved.
The hydrogen society is a term that have received world notoriety. This is due to increasing on c... more The hydrogen society is a term that have received world notoriety. This is due to increasing on costs to obtain fossil fuels and the emission of many pollutants to atmosphere, mainly greenhouse gases. A portion of climates changes is directly related with this emissions, causing serious damages on human survival. The hydrogen is called the future fuel, this is due its clean combustion, that no emission pollutants to atmosphere. A enough clean option to obtain hydrogen is the utilization of renewable sources. This article reviews the forms to production, storage, distribution and utilization of hydrogen like as energy carrier, inserted on context of utilization of two renewable sources, the solar and eolian, for production of electrolytic hydrogen.
O presente estudo apresenta uma analise sobre a seguranca na instalacao de sistemas fotovoltaicos... more O presente estudo apresenta uma analise sobre a seguranca na instalacao de sistemas fotovoltaicos (FV) em aeroportos, inicialmente apresentando os principais aeroportos que ja possuem sistemas instalados no mundo e os estudos ja feitos para implementacao no Brasil. Em seguida se faz uma analise em relacao a seguranca para as operacoes aeroportuarias, bem como as medidas de se mitigar os riscos. O estudo tem como objetivo auxiliar aos interessados em implementar sistemas FV em aeroportos, orientando quanto a localizacao, direcionamento dos paineis e seguranca dos componentes do sistema.
Este estudo do tipo qualitativo descritivo examina como é que a Alfabetização Energética (AE) est... more Este estudo do tipo qualitativo descritivo examina como é que a Alfabetização Energética (AE) está se constituindo ao nível internacional como uma componente educacional integrada no contexto escolar. Um levantamento de 17 conceitos nas disciplinas de Ciências Naturais, Física, Biologia, Química, Geografia e História, nos programas curriculares de África do Sul, Brasil, Índia e Portugal em 10 anos de ensino foi realizado. Os resultados indicam que a taxa de cobertura dos conceitos é de 30% para Africa do Sul, 23% para Portugal, 18% para Brasil e 11% para India. A concentração dos conceitos ocorre nas disciplinas de Ciências Naturais para África do Sul (67%), Brasil (50%) e Índia (61%) enquanto para Portugal concentra-se na disciplina de Química-Física com 73%. Portugal revela uma evolução de integração de conceitos superior aos outros países o que pode fertilizar para uma melhor promoção de Eficiência Energética (EE) e consciência ambiental. Quanto à interdisciplinaridade, África do...
In this paper an innovative hybrid model of time series prediction based on the combination of tw... more In this paper an innovative hybrid model of time series prediction based on the combination of two functions (linear and nonlinear) of the Holt-Winters and Artificial Neural Networks models is presented. This model is applied in wind speed in northeastern Brazil, and was able to perform short and long term forecasts with good accuracy. We highlight the efficiency of the proposed model in providing perfect adjustments to the data observed, being this affirmative according to the low values found in the statistical analysis of errors, for example, with percentage error of approximately 5.0%, and also with the value of the Nash-Sutcliffe coefficient of efficiency of approximately 0.96. These results were important for the accuracy of the data, so that they could follow the profile of the observed time series, mainly revealing greater similarities of maximum and minimum values between both series, thus showing the capacity of the model to represent characteristics of local seasonality. ...
Anais do Congresso Brasileiro de Automática 2020, 2020
Neste trabalho são apresentadas a modelagem e controle de um sistema de dessalinização por osmose... more Neste trabalho são apresentadas a modelagem e controle de um sistema de dessalinização por osmose reversa. As entradas do sistema são as válvulas de bypass e da água de concentrado. As saídas do sistema são o fluxo da água de produto e a pressão de entrada do sistema. O modelo não linear obtido é linearizado e para o ponto de operação considerado um controlador por alocação de pólos com ação integral é projetado. Resultados preliminares são promissores, com bons resultados para rastreamento de referência e rejeição de distúrbios.
Solar energy is one of the main renewable energy sources capable of contributing to global energy... more Solar energy is one of the main renewable energy sources capable of contributing to global energy demand. However, the solar resource is intermittent, making its integration into the electrical system a difficult task. Here, we present and compare two machine learning techniques, deep learning (DL) and support vector regression (SVR), to verify their behavior for solar forecasting. Our testing from Spain showed that the mean absolute percentage error for predictions using DL and SVR is 7.9% and 8.52%, respectively. The DL achieved the best results for solar energy forecast, but it is worth mentioning that the SVR also obtained satisfactory results.
New technologies are coming to improve the use of power for the consumers in a bigger time from p... more New technologies are coming to improve the use of power for the consumers in a bigger time from photovoltaic source. This paper works arrangement with two types of technology of energy storage: Battery and electrolyzer-fuel cell set and three types of photovoltaic use: stand-alone, hybrid and connected to the grid.
The increasing energy demand is a global concern, directly associated with indicators of greenhou... more The increasing energy demand is a global concern, directly associated with indicators of greenhouse gases and air pollution. These, in turn, are directly related to the physical, social and economic aspects of cities. One way to minimize such impacts is to diversify the energy matrix with renewable sources. On the other hand, the use of wind and solar plants are susceptible to multiple conflicts, due to urban aesthetics, technology scale or directionality of the energy flow across individual property limits. Considering that the urban form directly impacts the energy demand and the existence of conflicts arising from the use of renewable sources, the integration between urban and energy planning plays an important role in mitigating the risks associated with the growth of renewable generation. With such motivation, we propose a comparative analysis of the main tools of urban and / or energy planning through a systematic review of the literature. The methodology of the literature rev...
O presente artigo tem como objetivo analisar a viabilidade do uso de paineis fotovoltaicos (FV) e... more O presente artigo tem como objetivo analisar a viabilidade do uso de paineis fotovoltaicos (FV) em duas Estacoes Elevatorias de Agua (E.E.A.),em Fortaleza e em Cascavel, no Estado do Ceara.A planta FV faz uso do mecanismo de compensacao, onde a eletricidade gerada pelos modulos FV e injetada na rede da concessionaria local e o valor descontado na conta de energia eletrica.O desenvolvimento e analise do projeto e realizado com auxilio do software de analise de projetos de energia limpa RETScreen. Por meio desse programa sao realizados os estudos sobre producao de eletricidade, custos do ciclo de vida e viabilidade financeira do projeto. Para a estimativa dos custos de implantacao do projeto sao considerados tres aspectos: custo de aquisicao de modulos FV, infraestrutura/interligacao com a rede e demais custos de implantacao. O projeto em estudo tem um custo total estimado de R$ 11.240.442,51 levando em consideracao que a capacidade instalada do sistema e de 1793 kWp. O retorno de cap...
In the present paper a statistical analysis of the wind speed in Ceara state, Northeast Brazilian... more In the present paper a statistical analysis of the wind speed in Ceara state, Northeast Brazilian, is made aiming to places whose wind energy potential can be used to electricity production. The best periods for wind energy use are shown; wind speeds from different sites are compared. Wind speed data measured at 70 meters height in the state for the 2005 show that the best wind speed values are found in the diurnal period. In the coastal area, sites with average wind speeds higher than 10 m/s are found, as Acarau and Barroquinha. On the mountains, sites with average wind speeds higher than 8 m/s are found, as Ubajara. Shape factor values of the Weibull distribution for sites in the coast in the dry period are in agreement with those found in the literature.
Floating photovoltaic (FPV) plants in reservoirs can contribute to reduce water evaporation, incr... more Floating photovoltaic (FPV) plants in reservoirs can contribute to reduce water evaporation, increase power generation efficiency, due to the cooling process, and reduce competitiveness in land use. Based on this motivation, we propose a new methodology for sizing FPV plants in dams of semi-arid regions using the flood duration curve. The methodology innovations are no use of commercial software, the possibility of choosing the reliability level, the application in reservoirs of semi-arid areas of the world, and the use of a graphic analysis of the reservoir hydrological behavior. The case studies in the Brazilian and Australian semi-arid consider two scenarios: high reliability level (90%, scenario 1) and low reliability level (70%, scenario 2). The reliability level is linked to the electricity production; the evaporation reduction is proportional to the FPV plant area.
The present paper describes the design, development, implementation and validation of an Internet... more The present paper describes the design, development, implementation and validation of an Internet of Things (IoT) network with sensors signal conditioning circuits for monitoring decentralized photovoltaic (PV) plants. The system intends to reduce costs of commercial dataloggers and sensing modules which require control and data storage using proprietary software. We applied our IoT monitoring network in three PV plants installed in Fortaleza and Maracanaú cities, Brazil, and in Cologne, Germany. The applied embedded solutions (namely, ESP 8266 and ESP 32) are based on free software and hardware and communicate with a Cloud server via Wi-Fi. A website, called Web Monitor, was developed in PHP for online and real-time data consultation in form of charts. The main objective of the proposal is to measure PV module temperature, providing data for the analysis of PV module’s efficiency and for fault detection in case of PV cells overheating. Solar irradiance, ambient temperature, relative air humidity and wind speed are also monitored, getting more data to analyze the effect of meteorological parameters on the PV module’s performance. The proposed system was designed in compliance with IEC 61724:1998 standard and the obtained charts are discussed in the results section considering different periods of the year. Finally, we validate the proposed temperature conditioning system with a commercial piece of equipment and a correlation of 0.9999 was achieved.
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Papers by Paulo Carvalho