Utilização do cavaco de madeira como combustível alternativo para a produção de vapor de água em uma caldeira aquatubular com grelha fixa do tipo PIN HOLE

The steady increase in the price of oil and its derivatives, carbon credits, the concern with the environment combined with the precipitation of rain water and lack of water resources that Brazil has suffered in 2014 caused a migration of participation sources of energy in the Brazilian energy matrix. The hydropower sector suffered big drop at 2013 and is suffering so far, contributing thus to the generation and cogeneration of thermal energy using renewable energy sources such as: sugarcane bagasse, wood chips, rice husks, among others. The selling price of the electricity market reached the level of R$ 807, 00 MWh in January 2014 (Source: ANEEL), heating the Brazilian thermoelectric sector. Although thermoelectric use in bulk water as vaporizing fluid to produce electricity and use in various processes, water reuse plans have become an important factor in these industries. The increased use of biomass has been the bagasse which is allied to the sugarcane sector, strong market in Brazil, and consists basically use the rest of sugar cane, sugarcane industries that would play out. The sugar and ethanol industry is very unstable and only lasts for 6-8 months a year, and the remaining time in the period known as between crop that corresponds to the planting and harvesting of sugarcane and then enter the period of vintage which is the constant cane harvesting and crushing it. This instability of the market and the thermoelectric idle period leads the thermoelectric industries to seek other sources of renewable energy, such as wood chips (pine, Eucalyptus, Orange), rice husk, sorghum among others, to not be dependent on alcohol sector. The present work aims to study the use of wood chips as an alternative biomass for burning a fuel that essentially uses bagasse, the thermoelectric in question consists of two boilers that produce together 350 t / h ... (Complete Abstract click electronic access below)

A mercantilização dos bens naturais no setor elétrico: o caso da UHE Barra Grande

Pós-graduação em Geografia - FCT

Green supply chain management and environmental performance of firms in the bioenergy sector in Brazil: an exploratory survey

To achieve sustainable development, supply chains must become greener. In this context, the importance of green supply chain management (GSCM) increases because it can contribute to improving firms'environmental performance (EP). However, little is known about these subjects in the context of firms in the bioenergy sector (sugarcane and ethanol production in Brazil). Thus, the objective of this work is to present the results of a survey conducted on 80 micro-, small-, and medium-sized firms that are suppliers in the Brazilian bioenergy sector (sugarcane and ethanol production). These results indicate that GSCM practices strengthen the EP of firms in the sector. Therefore, this article contributes to the existing literature because it addresses the relationship between GSCM and EP in an understudied sector (sugarcane and ethanol production). (C) 2014 Elsevier Ltd. All rights reserved.

Simulación de mercado diario y previsión a 20 años del sector eléctrico peninsular

En este proyecto se crea un modelo de casación de ofertas de venta y de adquisición de energía eléctrica. Este modelo sirve para simular, de manera simplificada, el proceso de casación que tiene lugar en el mercado Diario peninsular (España y Portugal). Con el fin de averiguar el comportamiento del sector eléctrico, en este aspecto, en el futuro, se extrapolan las ofertas de adquisición según una evolución prevista de demanda y se utiliza el modelo creado para prever el mix energético y los precios de la electricidad. Esta previsión se hace en base a tres escenarios. Uno en el que hay un importante autoabastecimiento de energía eléctrica en los puntos de consumo residenciales; otro en el que el vehículo eléctrico entra de manera significativa en el parque automovilístico peninsular; y el tercero en el que las energías renovables asumen el principal peso de la cobertura de energía eléctrica. Abstract In this project a model for matching sale and purchase bids of electricity power is created. The model simulates, simplified, the process of setting energy and prices in the Daily Market of the Iberian Peninsula (Spain and Portugal). In order to determine the electricity sector behavior in the future, purchase bids are extrapolated following a prevision of demand and the model is used to predict the generation technologies mix and electricity prices. This forecast is based on three possible scenarios. The first one assumes significant self-supply of electricity in residential areas; the second one considers that the electric vehicle relevantly enters the peninsular fleet; the third one supposes that renewable energies cover the majority of electric energy.

Risco de mercado na comercialização de energia elétrica: uma análise estruturada com foco no ambiente de contratação livre - ACL.

A motivação para o desenvolvimento desse trabalho surge em um momento em que se verifica uma participação cada vez mais significativa das fontes energéticas renováveis não convencionais no País. Não obstante, o cenário de evolução evidencia que o arcabouço regulatório e as regras de mercado não acompanharam as especificidades inerentes à exploração dessas fontes. Assim, para que se mantenha adequado ritmo de inserção na matriz energética, devem ser buscadas opções para que fontes alternativas sejam cada vez mais competitivas na atual configuração do mercado energético. A contribuição dessa pesquisa, portanto, centra-se na análise dos riscos de mercado incorridos por esses geradores de fontes intermitentes de energia ao comercializarem energia no ambiente de contratação livre. Nessa perspectiva, a Dissertação foi desenvolvida abordando tipos de geração de energia e suas características técnicas e econômicas, legislação do setor elétrico, regras de comercialização, balanço energético do sistema, formação de preços no mercado de curto prazo e precificação de contratos no ACL, diferença de preços entre submercados, requisitos de flexibilidade e sazonalidade nos contratos de venda a consumidores livres e seu impacto na precificação de contratos, identificação de comportamento energético complementar para mitigação de riscos de mercado entre fontes renováveis e rebatimento na formulação de mecanismo de hedge, análise de portfólio de contratos e estratégia ótima de contratação de energia para agentes geradores atuando no ACL. Como resposta ao desafio de equacionar o impasse surgido na comercialização de fontes de produção sazonal, propõe-se um modelo para definir estratégias de contratação para agentes geradores e comercializadores a partir da complementação energética entre diferentes tipos de fontes, de forma a maximizar os ganhos de comercialização para um risco estabelecido. Busca-se a composição ideal dessas fontes na carteira de um comercializador para minimizar o risco de exposição à volatilidade dos preços do mercado de curto prazo. Isso é possível em virtude das compensações energéticas feitas entre as diferentes fontes em um portfólio combinado, mitigando a receita em risco decorrente das variações que existem nos preços de curto prazo e na produção energética. De forma complementar, estruturou-se um modelo de negócio no qual uma empresa detentora de ativos de geração hidrelétrica compra os direitos de produção de uma eólica e/ou biomassa para incorporar ao seu portfólio e vender como contrato por quantidade. Determinou-se o volume de energia a ser comprado de cada fonte, o preço, a estratégia mais indicada de contratação e a mitigação de fatores de risco contemplados nos contratos de venda, buscando maximizar os ganhos de comercialização condicionada a critérios de risco pré-fixados.

Electricity without borders: a plan to make the internal market work. Bruegel Blueprint Series 20, 5 September 2013

The most straightforward European single energy market design would entail a European system operator regulated by a single European regulator. This would ensure the predictable development of rules for the entire EU, significantly reducing regulatory uncertainty for electricity sector investments. But such a first-best market design is unlikely to be politically realistic in the European context for three reasons. First, the necessary changes compared to the current situation are substantial and would produce significant redistributive effects. Second, a European solution would deprive member states of the ability to manage their energy systems nationally. And third, a single European solution might fall short of being well-tailored to consumers’ preferences, which differ substantially across the EU. To nevertheless reap significant benefits from an integrated European electricity market, we propose the following blueprint: First, we suggest adding a European system-management layer to complement national operation centres and help them to better exchange information about the status of the system, expected changes and planned modifications. The ultimate aim should be to transfer the day-to-day responsibility for the safe and economic operation of the system to the European control centre. To further increase efficiency, electricity prices should be allowed to differ between all network points between and within countries. This would enable throughput of electricity through national and international lines to be safely increased without any major investments in infrastructure. Second, to ensure the consistency of national network plans and to ensure that they contribute to providing the infrastructure for a functioning single market, the role of the European ten year network development plan (TYNDP) needs to be upgraded by obliging national regulators to only approve projects planned at European level unless they can prove that deviations are beneficial. This boosted role of the TYNDP would need to be underpinned by resolving the issues of conflicting interests and information asymmetry. Therefore, the network planning process should be opened to all affected stakeholders (generators, network owners and operators, consumers, residents and others) and enable the European Agency for the Cooperation of Energy Regulators (ACER) to act as a welfare-maximising referee. An ultimate political decision by the European Parliament on the entire plan will open a negotiation process around selecting alternatives and agreeing compensation. This ensures that all stakeholders have an interest in guaranteeing a certain degree of balance of interest in the earlier stages. In fact, transparent planning, early stakeholder involvement and democratic legitimisation are well suited for minimising as much as possible local opposition to new lines. Third, sharing the cost of network investments in Europe is a critical issue. One reason is that so far even the most sophisticated models have been unable to identify the individual long-term net benefit in an uncertain environment. A workable compromise to finance new network investments would consist of three components: (i) all easily attributable cost should be levied on the responsible party; (ii) all network users that sit at nodes that are expected to receive more imports through a line extension should be obliged to pay a share of the line extension cost through their network charges; (iii) the rest of the cost is socialised to all consumers. Such a cost-distribution scheme will involve some intra-European redistribution from the well-developed countries (infrastructure-wise) to those that are catching up. However, such a scheme would perform this redistribution in a much more efficient way than the Connecting Europe Facility’s ad-hoc disbursements to politically chosen projects, because it would provide the infrastructure that is really needed.

Smart electricity grids: A very slow deployment in the EU. Egmont Paper No. 74, February 2015

Summary. The European electricity sector will have to deal with a huge challenge in the decades to come. On the one hand, electrical power is increasingly substituted for other forms of energy. It has been forecast that electricity demand will increase in the future (notably because of new needs in transport and heat sectors), although it is currently stagnant, mainly because of the economic crisis. Unless a major alternative energy source is discovered, electricity will become the central energy pillar in the long term. On the other hand, electricity production remains uncertain and will depend on numerous factors: the growth of renewable energy and decentralized energy, the renewal of old power generation capacities, increased external dependency, CO2 charges, etc. This increases the demand for electricity networks that are more reliable, more efficient, and more flexible. Europe’s current electricity networks are ageing, and, as already indicated by the International Energy Agency, many of them will need to be modernized or replaced in the decades to come. Finally, the growing impact of energy trading also needs to be taken into account. These considerations explain the need to modernize the electric grid through various ICT means. This modernization alone may allow the grid to become more flexible and interactive, to provide real time feedback, more adaptation to a fluctuating demand, and finally to reduce the global electricity costs. The paper begins with a description of the EU definition of the term ‘smart grid’ (§ 1) and of the body in charge of advising the Commission (§ 2). The EU legal framework applicable to smart grids is also detailed (§ 3). It is a rather complex domain, connected to various regulations. The paper then examines three critical factors in the development of smart grids (and smart meters as a precondition). Standardization is quite complex, but absolutely essential (§ 4). Innovation is not easily put into action (§ 5). Finally, as digital insecurity has worsened dramatically in recent years, the security of electricity networks, and especially their multiplied electronic components, will become increasingly important (§ 6). Lastly, the paper provides a concise overview of the progress of smart grids in the EU in recent years (§ 7). In a nutshell, the conclusion is that progress is quite slow, many obstacles remain, and, given the appearance of many new regulatory problems, it would be useful to organize a review of the present EU strategy.

Investement appraisal in a deregulated electricity market

This thesis analyses the impact of deregulation on the theory and practice of investment decision making in the electricity sector and appraises the likely effects on its long term future inefficiency. Part I describes the market and its shortcomings in promoting an optimal generation margin and plant mix and in reducing prices through competition. A full size operational model is developed to simulate hour by hour operation of the market and analyse its features. A relationship is established between the SMP and plant mix and between the LOLP and plant margin and it is shown bow a theoretical optimum can be derived when the combined LOLP payments and the capital costs of additional generation reach a minimum. A comparison of prices against an idealised bulk supply tariff is used to show how energy prices have risen some 12% in excess of what might have occurred under the CEGB regime. This part concludes with proposals to improve the marl

Modelagem e análise dinâmica de um sistema de conversão de energia eólica dotado de gerador síncrono de imã permanente utilizando a plataforma ATP

Human development requires a broad balance between ecological, social and economic factors in order to ensure its own sustainability. In this sense, the search for new sources of energy generation, with low deployment and operation costs, which cause the least possible impact to the environment, has been the focus of attention of all society segments. To do so, the reduction in exploration of fossil fuels and the encouragement of using renewable energy resources for distributed generation have proved interesting alternatives to the expansion of the energy matrix of various countries in the world. In this sense, the wind energy has acquired an increasingly significant role, presenting increasing rates of power grid penetration and highlighting technological innovations such as the use of permanent magnet synchronous generators (PMSG). In Brazil, this fact has also been noted and, as a result, the impact of the inclusion of this source in the distribution and sub-transmission power grid has been a major concern of utilities and agents connected to Brazilian electrical sector. Thus, it is relevant the development of appropriate computational tools that allow detailed predictive studies about the dynamic behavior of wind farms, either operating with isolated load, either connected to the main grid, taking also into account the implementation of control strategies for active/reactive power generation and the keeping of adequate levels of voltage and frequency. This work fits in this context since it comprises mathematical and computational developments of a complete wind energy conversion system (WECS) endowed with PMSG using time domain techniques of Alternative Transients Program (ATP), which prides itself a recognized reputation by scientific and academic communities as well as by electricity professionals in Brazil and elsewhere. The modeling procedures performed allowed the elaboration of blocks representing each of the elements of a real WECS, comprising the primary source (the wind), the wind turbine, the PMSG, the frequency converter, the step up transformer, the load composition and the power grid equivalent. Special attention is also given to the implementation of wind turbine control techniques, mainly the pitch control responsible for keeping the generator under the maximum power operation point, and the vector theory that aims at adjusting the active/reactive power flow between the wind turbine and the power grid. Several simulations are performed to investigate the dynamic behavior of the wind farm when subjected to different operating conditions and/or on the occurrence of wind intensity variations. The results have shown the effectiveness of both mathematical and computational modeling developed for the wind turbine and the associated controls.

An alternative benchmarking approach for electricity utility regulation using maximum entropy

The main purpose of this study is to present an alternative benchmarking approach that can be used by national regulators of utilities. It is widely known that the lack of sizeable data sets limits the choice of the benchmarking method and the specification of the model to set price controls within incentive-based regulation. Ill-posed frontier models are the problem that some national regulators have been facing. Maximum entropy estimators are useful in the estimation of such ill-posed models, in particular in models exhibiting small sample sizes, collinearity and non-normal errors, as well as in models where the number of parameters to be estimated exceeds the number of observations available. The empirical study involves a sample data used by the Portuguese regulator of the electricity sector to set the parameters for the electricity distribution companies in the regulatory period of 2012-2014. DEA and maximum entropy methods are applied and the efficiency results are compared.

Saúde e capacidade para o trabalho de eletricitários do Estado de São Paulo

Apesar dos elevados riscos à saúde e capacidade para o trabalho dos eletricitários, há carência de estudos sobre o tema no Brasil. O objetivo desse estudo é identificar o perfil de saúde e capacidade para o trabalho de eletricitários de São Paulo. Foi feito um estudo transversal junto a 475 trabalhadores de uma empresa do setor eletricitário. A coleta de dados foi por meio de questionários sobre capacidade para o trabalho, estado de saúde, estresse no trabalho, atividade física, dependência ao tabaco e ao álcool. A consistência interna das escalas foi avaliada usando o coeficiente alfa de Cronbach. Foi feita análise descritiva por meio das médias, desvios-padrão, valores mínimos e máximos dos escores e proporções para as variáveis qualitativas. O estado de saúde dos trabalhadores apresentou pontuação elevada nas dimensões analisadas, com médias entre 72,8 a 91,2 (escore de 0,0 a 100,0 pontos). A capacidade para o trabalho teve pontuação elevada, com média de 41,8 (escore de 7,0 a 49,0 pontos). Concluiu-se que os trabalhadores da população de estudo apresentaram elevados padrões do estado de saúde e da capacidade para o trabalho. Sugere-se o desenvolvimento de estudos longitudinais para avaliar relações causais e a existência de efeito do trabalhador sadio.

Chemical composition of bovine milk from Minas Gerais State, Brazil

Aiming at international competitiveness of the Brazilian dairy sector, new governmental policies were released to improve quality and safety of bovine milk. In this context, it is important to quantify essential and toxic chemical elements. Here, the composition of milk samples taken at 32 dairy farms in Minas Gerais State was assessed by instrumental neutron activation analysis (INAA) and inductively coupled plasma mass spectrometry (ICP-MS), besides the evaluation of usual quality parameters. Significant differences were found for Ba, K, Na and fat content amongst dairy farms with diverse quality levels established on basis of somatic cell and total bacterial count.

Meritocracia ?? brasileira: o que ?? desempenho no Brasil?

O artigo trata da quest??o da meritocracia e da avalia????o de desempenho no setor p??blico brasileiro e na sociedade sob uma perspectiva mais ampla, enfatizando a diferen??a entre a exist??ncia de sistemas meritocr??ticos formais e sua legitimidade social. Para a autora, o cerne desta discuss??o passa pelo entendimento da diferen??a entre sistemas meritocr??ticos e ideologia da meritocracia e pela compreens??o dos pressupostos culturais que est??o informando este debate. O artigo situa a quest??o da meritocracia em contextos mais amplos, como a teoria da administra????o, a perspectiva intercultural e a ??tica hist??ricosociol??gica, sem perder de vista as especificidades da sociedade brasileira.

Gest??o do conhecimento como sistema de gest??o para o setor p??blico

O conhecimento e a gest??o do conhecimento t??m sido focos de uma intensa discuss??o sobre como as organiza????es privadas podem obter vantagens competitivas e atingir elevados patamares de flexibilidade, produtividade e inova????o, sem que, no entanto, esta disciplina seja devidamente debatida e/ou incorporada pelo setor p??blico brasileiro. A partir da perspectiva dos autores de maior prest??gio no assunto, este trabalho apresenta os principais conceitos e aspectos relacionados a este novo paradigma de gest??o organizacional, de modo a identificar quais seriam os principais desafios para a implanta????o de projetos de gest??o do conhecimento no ??mbito da administra????o p??blica. Adicionalmente, este trabalho prop??e a ado????o de um novo modelo de gest??o do conhecimento, mais consistente e adequado ??s organiza????es p??blicas. O modelo de gest??o apresentado prop??e-se a servir como susbs??dio para um debate te??rico e metodol??gico sobre como a gest??o do conhecimento poderia ser incorporada ?? tarefa de buscar melhores n??veis de gest??o para as organiza????es p??blicas brasileiras, de forma a torn??-las mais capacitadas a fazerem frente ??s interfer??ncias que j?? provocaram a fal??ncia das inst??ncias de planejamento e or??amento no setor p??blico, o abandono da padroniza????o e da melhoria dos procedimentos administrativos, a desestrutura????o da fun????o p??blica e das pol??ticas de recursos humanos, a persistente descontinuidade de projetos e de pol??ticas p??blicas, assim como permita resgatar a credibilidade nos mecanismos internos de repress??o e de puni????o ??queles agentes que adotam pr??ticas ou condutas que v??o de encontro aos princ??pios morais e ??s normas jur??dicas estabelecidas.

O t??nel no fim da luz: a privatiza????o do setor el??trico em Mato Grosso

Este artigo tem por objetivo analisar a forma????o de consensos sociais e pol??ticos para a reforma do Estado e de seu aparelho em n??vel estadual, conforme a governabilidade democr??tica. Optou-se por uma pesquisa sobre a privatiza????o das Centrais El??tricas Mato- Grossenses S.A. (Cemat), considerada representativa tanto da reforma empreendida pelo Estado de Mato Grosso quanto das dificuldades do setor el??trico em n??vel nacional. O referencial metodol??gico dessa pesquisa ?? composto de um problema e de quatro hip??teses de trabalho. Trata-se de estudo de caso da esp??cie ???provas de plausibilidade???, em que, por uma aplica????o iterativa, apresenta-se uma proposi????o te??rica inicial e, em seguida, as conclus??es da pesquisa s??o comparadas, o que permite sua revis??o e compara????o. Para tanto, descrevem-se a privatiza????o da Cemat e os problemas da desestatiza????o do setor el??trico brasileiro no seu conjunto. Por fim, na conclus??o, verifica-se a validade das hip??teses e fazem-se algumas considera????es finais sobre a pesquisa.