No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
Abstract
An overview of the world energy matrix is presented with some specific aspects on non-renewable energy, climate changes and challenges for the development of renewable energy sources. The chapter also shows historical data on global energy consumption by energy sources and a prospection for the next 20 years. This evaluation is followed by an analysis on the Brazilian energy matrix, consumption, electrical systems characteristics, programs and incentives.
Renewable energy must be prioritized by humankind, mainly if there is an expected increase of 50% in energy consumption by 2030 and climate change scenarios are also confirmed. Urban areas consume 70% of the available energy on the planet. Brazil, the largest country in South America, concentrates more than 85% of its population in urban areas, facing a challenge to increase the renewable power plants in its energy matrix. This work presents the solar radiation components behavior for the city of Salvador to contribute with initiatives for the use of solar energy resource. Firstly, a radiometric platform was implemented to obtain direct measurements of global (EG) and diffuse (EDF) components of incoming solar radiation at the surface. The knowledge of EDF is an important requirement to support photovoltaic system projects, and there is no information on direct measurements of this component in the State of Bahia. The diffuse radiation measurement device (DRMD) was designed and built for this purpose. The measurements of solar radiation components performed in this research were submitted to a specific quality control, statistically analyzed and used to evaluate the performance of different empirical models to represent the behavior of EDF in the tropical coastal city. The results demonstrate the potential to explore solar energy in the city of Salvador, with annual values of sunshine higher than 2200 h year−1 and average daily intensities of EG and EDF equal to 18.7 MJm−2day−1 and 7.35 MJm−2day−1, respectively. The analysis of the diurnal cycle shows that EG in summer reaches a maximum of 4.2 MJm−2h−1 and in the rainy season it reaches a minimum of 3.7 MJm−2h−1, both at noon, and in summer the EDFh is 35% of the EGh and it is 46% in the rainy season.
In petroleum reservoirs, parameters such as permeability, porosity, extension, and skin effects, have a high level of uncertainty. Different techniques attempt to improve the estimation of these parameters to improve production forecasting and cost reduction. The conventional production test, for example, requires the analysis of reservoir well pressure data. However, these data have several noise sources, such as the tidal effect, that may compromise the accuracy of test results. This letter proposes a method to smooth the noise generated by the tidal effect from well pressure data, using mathematical tools, such as the Fourier transform. We apply the discrete sine transform type I (DST-I) to filter the signal, and we use the pressure derivative to verify the results.
Energy production and use present environmental impacts, but the present consumption patterns can be improved through a more efficient use of energy and a shift from fossil fuels to renewable sources of energy. Due to hydroelectricity and bioethanol, Brazil still has a comfortable position compared to the rest of the world. Self-sufficient in oil, the country today discusses how to supply natural gas and electricity in the medium and long terms, with different positions about the path to follow. The present article proposes recommendations, with special focus on the electricity sector.
Metals such as cadmium, gallium, germanium, indium, selenium, and tellurium are important mineral materials used in current photovoltaic cell technology. Most of the world's primary supply of these mineral commodities is recovered as byproducts from ores processed mainly for the purpose of producing aluminum, copper, lead, and zinc and, in the case of germanium, from ash derived from burning coal for the production of energy. In some cases, the refined metals originate in the countries in which they are mined, while in other cases, intermediate products containing the metals and refined metals are recovered by processers located in other countries. Assuming that the modest rate of market penetration of electricity from photovoltaic cells and competing markets increases demand for cadmium, gallium, and germanium, the resulting new demand can be met in relatively quick order with the expansion of existing recovery circuits or the addition of new circuits. It is very unlikely that, under most scenarios, the need would arise to mine more bauxite, copper, and zinc ore or to burn more coal to satisfy anticipated material requirements to meet the photovoltaic-generated demand for these mineral materials. For other metals, such as indium, selenium, and tellurium, targeted mineral exploration and improvements in metallurgical recoveries are likely to be needed to meet demand requirements. Substitution for these materials in nonphotovoltaic applications could also "free up" supply. Conversely, however, other new applications can produce supply constraints or increase metal prices and place pressure on their use in photovoltaic technology. The supply of these metals from secondary sources will likely increase over time when photovoltaic cells are recycled as a result of breakage or when they reach the end of their useful life of approximately 20 to perhaps 30 years (U.S. Department of Energy, Solar Technologies Program, 2008a). Other than perhaps short term interruptions resulting from market forces or geopolitical events, it is not anticipated that there will be any long term material constraints that would prevent the development of a significant amount of energy from photoelectric cells. Reserve estimates are not static; although a particular metal might be considered rare and scarce, if a profit can be made from its recovery, then there will likely be no long-term shortage. Technological advancements driven by the desire to produce energy at a lower cost will likely result in increases in efficiency requiring smaller amounts of these metals per unit of energy produced, substitution with other materials, and other advancements in science.
No âmbito das discussões sobre a questão energética, aprofundada pelo cenário internacional de escassez do petróleo e pelas mudanças no clima, ocasionadas pela queima de combustíveis fósseis, surgem pesqui-sas e estudos técnicos, econômicos e de impactos socioeconômicos e ambientais de empreendimentos de energias alternativas ou renováveis voltados para o desenvolvimento de alternativas na produção de ener-gia, a partir de matéria orgânica de origem animal e vegetal, a biomassa; a partir da força dos ventos, a chamada energia eólica; através da captação da luz do sol, a energia solar, e a partir de pequenas centrais hidroelétricas, as quais atendem a demandas em áre-as periféricas ao sistema de transmissão. Nesta busca por fontes alternativas o Brasil apresen-ta grande diferencial em relação a outros países, pois a sua imensa biodiversidade, permite a geração de energia por vários meios, incluindo as fontes de ener-gia renováveis como a hidrelétrica e também a busca pelo desenvolvimento de fontes alternativas como a utilização da biomassa, para produção de combus-tíveis renováveis, como o álcool, o biodiesel, e, mais recentemente, o H-bio (AGRONEGÓCIOS..., 2006). Nessa direção, este artigo tem por objetivo expor a discussão atual sobre a nova ordem energética mun-dial, em que se aborda a preocupação pela busca da auto-suficiência em energia, em que também se con-ceituam as energias renováveis, definindo-as quanto aos tipos. Além disso, abordam-se os investimentos já realizados e em andamento, assim como as pes-quisas na área de combustíveis alternativos no Brasil e no estado da Bahia.
Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Elétrica, 2007. Este trabalho apresenta uma proposta de nova resolução passível de ser aproveitada e publicada pela Agência Nacional de Energia Elétrica (ANEEL) versando sobre a qualidade da energia elétrica fornecida às unidades consumidoras do Brasil. Nesse sentido, a abordagem da qualidade da energia elétrica é analisada e tratada prioritariamente sob o foco do consumidor, isto é, considerando as suas reais necessidades técnicas, os seus direitos e deveres e ainda, em estrita consonância com a verdadeira missão da concessionária e do órgão Regulador: prestar um serviço adequado. O contexto da matéria cotejada neste trabalho considera a vinculação direta da qualidade da energia elétrica à conformidade da tensão elétrica disponibilizada, isto é, a Tensão de Fornecimento no ponto de entrega das unidades consumidoras em relação aos parâmetros indicadores ou de referência. Com vistas a oferecer adequada visão do setor elétrico e pavimentar a construção do modelo da nova resolução, na parte inicial o trabalho apresenta o registro dos principais fatos que marcaram a evolução da prestação do serviço público de energia elétrica no Brasil, sempre com a atenção direcionada à qualidade da energia elétrica. Assim, a leitura acurada permite constatar aspectos como a preocupação inicial do consumidor em ter disponível a energia elétrica, a evolução da legislação setorial incluindo os principais atos regulatórios (leis, decretos, Portarias e Resoluções), a alternância dos modelos de capital predominante dos agentes concessionários, a situação da matriz de energia elétrica e as maiores usinas hidrelétricas com potência instalada superior a 1.000 MW, os diferentes tipos de consumidores no ambiente atual e, do lado dos agentes concessionários, as preocupações com a competitividade, a reformatação, a gestão e o mercado. No contexto da regulação, o trabalho desenvolve análise do cenário histórico e, com fundamento na fidelidade da legislação vigente, esclarece a diferenciação conceitual da continuidade do fornecimento e da qualidade da energia elétrica, bem como da energia elétrica como produto ou serviço, além de analisar os atos regulatórios específicos sobre a qualidade de energia elétrica, isto é, a Portaria DNAEE n° 047/78 e a Resolução ANEEL nº 505, de 26 de novembro de 2001. Na seqüência, com o conhecimento de todo esse cenário, e alicerçado na metodologia da verificação, julgamento e ação, o trabalho desenvolve e apresenta a proposta de nova resolução sobre a qualidade da energia elétrica, a qual revisa toda a Resolução ANEEL nº 505/2001 vigente e acrescenta os Capítulos referentes a Variações de Tensão de Curta Duração (VTCD), Transitórios, Desequilíbrios e Assimetrias, Distorções Harmônicas e Flutuações de Tensão, definindo indicadores e inserindo critérios de prazos e penalidades aplicáveis ao responsável pela ocorrência do distúrbio. Finalmente, cabe elencar os principais pontos a serem objeto de futuras providências: i) ANEEL: estimular fabricantes e entidades de pesquisa a desenvolver medidores eletrônicos com os atributos fixados na minuta de resolução; ii) ANEEL: analisar a minuta de resolução proposta, efetuar os ajustes julgados necessários e disponibilizar o texto revisado para audiência pública presencial; iii) ANEEL: consolidar as contribuições recebidas, publicar nova resolução sobre qualidade de energia elétrica; iv) ANEEL, ABRADEE e concessionárias: implementar alternativas técnico-econômicas de alterações nos sistemas elétricos de distribuição que visem melhorar a qualidade da tensão de fornecimento; v) ANEEL: estabelecer em resolução específica, critérios para a determinação de um Índice ANEEL de Qualidade de Energia Elétrica (IAQEE) para cada concessionária, o qual reúna e consolide todos os demais indicadores de qualidade de energia elétrica fornecida;vi) ANEEL e órgão regulador similar do Ministério do Desenvolvimento, Indústria e Comércio Exterior (MDIC): desenvolver estudos com vistas à publicação de Portaria ou Resolução, conjunta ou não, estabelecendo critérios e procedimentos com vistas a garantir ao consumidor o ressarcimento a que tiver direito em função de redução de vida útil especificada pelo fabricante autorizado do equipamento eletroeletrônico, sob condições normais de utilização. __________________________________________________________________________________________ ABSTRACT This work introduces a proposal of resolution to be implemented by the Brazilian Electricity Regulatory Agency (ANEEL) on the quality of the electric energy supplied to consumer units in Brazil. In this direction, the quality of the electric energy is analyzed and considered mainly under the consumer’s point of view, that is, considering their real technical needs, their rights and duties and still, in strict accordance to the true mission of the concessionaire and the Regulating agency: to give an adequate service. The context under discussion in this paper takes into consideration the direct relationship between quality of energy and the available electric tension, that is, the Tension of Supply in the point of delivery to the consumer unit in relation to the referenced parameters at this point. In order to offer an adequate vision of the electric sector and to pave the road to this new model of resolution, in the initial part the work presents the main facts related to the evolution of the electric energy public service in Brazil, focusing on the quality of the electric energy. The accurate reading sheds light on aspects such as the consumer’s initial concern in having electric energy available, the evolution of its legislation, including the main regulation acts (laws and Resolutions), the switching of the concessionary agents’ models of predominant capital, the electric energy source situation, the biggest power plants installed with power superior to 1,000 MW, the different types of consumers nowadays and, on the concessionary agents’ side, the concerns to competitiveness, rearrangement, management and marketing. Concerning the regulation, this paper develops an analysis of the historical scenario and, based on the current legislation, clarifies the conceptual differences between the continuity of supply and the quality of the electric energy, as well as discussing electric energy as product or service, and analyzing the specific regulatory framework on the quality of the electric energy, which are the Portaria DNAEE 047/78, and Resolution ANEEL nº 505, of November 26, 2001. Having sketched all this scenario, and based on the methodology of verification, judgment and action, the work presents and develops the new proposal of resolution on the quality of the electric energy, which revises all ANEEL’s nº 505/2001 Normative Resolution and adds Chapters referring to the Variations of Tension of Short Term (VTCD), Transitory, Disequilibrium and Asymmetries, Harmonic Distortions and Tension Fluctuations, defining indicators and adding criteria determining deadlines and penalties to the responsible for the disturbance. Finally, it is important to outline the main conclusions of this work for future consideration: (i) ANEEL to support and foster R&D initiatives in order to develop electronic energy meters considering the technical features included in proposed regulation; (ii) ANEEL to analyze the proposed regulation, make the deemed necessary adjustments and open specific public hearing process for discussion; (iii) ANEEL to take into consideration the contributions from the public hearing process and issue a new Resolution for quality of energy; (iv) ANEEL, ABRADEE and concessionaires to implement technical and economic measures in the distribution systems aiming to improve quality in the tension of supply; (v) ANEEL to issue resolution establishing specific criteria determining the Quality of Energy Index (IAQEE) for each concessionaire, consolidating other existing quality of energy indicators; (vi) ANEEL and Ministry of Industry, Development and Foreign Trade (MDIC) to develop and issue joint regulations establishing criteria and procedures to reimburse costumers that had the life of their electronic equipment diminished due to bad quality of supplied electricity.
Campo da energia elétrica no Brasil de 1880 a
- Jpp Gomes
- Mmf Vieira
Balanço Energético Nacional
- Mme Brasil
As dificuldades encontradas para implantação da Barragem do Castanhão e o acompanhamento das ações mitigadoras dos seus impactos ambientais. XXIV Seminário Nacional de Grandes Barragens
- Mzt Araújo
- Vppb Vieira
Energia e meio ambiente
- R A Hinrichs
- M Bach
- Dos Reis