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The application of the ordered list method and the dynamic programming to the unit commitmentUong, Hoang 01 January 1989 (has links)
The thesis presents a method of committing generating units in a hydro-thermal power system within practical computer resources such as computer time and data storage.
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Issues in energy financeKhoker, Zeigham Islam 23 March 2011 (has links)
Not available / text
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Stromerzeugung in Deutschland unter den Rahmenbedingungen von Klimapolitik und liberalisiertem Strommarkt : Bewertung von Kraftwerksinvestitionen mit Bayes’schen Einflussdiagrammen / Electricity generation in Germany under the conditions of climate policy and liberalized electricity market : valuation of power plant investments with Bayesian influence diagramsÖtsch, Rainald January 2012 (has links)
Mit der Liberalisierung des Strommarkts, den unsicheren Aussichten in der Klimapolitik und stark schwankenden Preisen bei Brennstoffen, Emissionsrechten und Kraftwerkskomponenten hat bei Kraftwerksinvestitionen das Risikomanagement an Bedeutung gewonnen. Dies äußert sich im vermehrten Einsatz probabilistischer Verfahren. Insbesondere bei regulativen Risiken liefert der klassische, häufigkeitsbasierte Wahrscheinlichkeitsbegriff aber keine Handhabe zur Risikoquantifizierung. In dieser Arbeit werden Kraftwerksinvestitionen und -portfolien in Deutschland mit Methoden des Bayes'schen Risikomanagements bewertet. Die Bayes'sche Denkschule begreift Wahrscheinlichkeit als persönliches Maß für Unsicherheit. Wahrscheinlichkeiten können auch ohne statistische Datenanalyse allein mit Expertenbefragungen gewonnen werden.
Das Zusammenwirken unsicherer Werttreiber wurde mit einem probabilistischen DCF-Modell (Discounted Cash Flow-Modell) spezifiziert und in ein Einflussdiagramm mit etwa 1200 Objekten umgesetzt. Da der Überwälzungsgrad von Brennstoff- und CO2-Kosten und damit die Höhe der von den Kraftwerken erwirtschafteten Deckungsbeiträge im Wettbewerb bestimmt werden, reicht eine einzelwirtschaftliche Betrachtung der Kraftwerke nicht aus. Strompreise und Auslastungen werden mit Heuristiken anhand der individuellen Position der Kraftwerke in der Merit Order bestimmt, d.h. anhand der nach kurzfristigen Grenzkosten gestaffelten Einsatzreihenfolge. Dazu wurden 113 thermische Großkraftwerke aus Deutschland in einer Merit Order vereinigt. Das Modell liefert Wahrscheinlichkeitsverteilungen für zentrale Größen wie Kapitalwerte von Bestandsportfolien sowie Stromgestehungskosten und Kapitalwerte von Einzelinvestitionen (Steinkohle- und Braunkohlekraftwerke mit und ohne CO2-Abscheidung sowie GuD-Kraftwerke).
Der Wert der Bestandsportfolien von RWE, E.ON, EnBW und Vattenfall wird primär durch die Beiträge der Braunkohle- und Atomkraftwerke bestimmt. Erstaunlicherweise schlägt sich der Emissionshandel nicht in Verlusten nieder. Dies liegt einerseits an den Zusatzgewinnen der Atomkraftwerke, andererseits an den bis 2012 gratis zugeteilten Emissionsrechten, welche hohe Windfall-Profite generieren. Dadurch erweist sich der Emissionshandel in seiner konkreten Ausgestaltung insgesamt als gewinnbringendes Geschäft. Über die Restlaufzeit der Bestandskraftwerke resultiert ab 2008 aus der Einführung des Emissionshandels ein Barwertvorteil von insgesamt 8,6 Mrd. €. In ähnlicher Dimension liegen die Barwertvorteile aus der 2009 von der Bundesregierung in Aussicht gestellten Laufzeitverlängerung für Atomkraftwerke. Bei einer achtjährigen Laufzeitverlängerung ergäben sich je nach CO2-Preisniveau Barwertvorteile von 8 bis 15 Mrd. €. Mit höheren CO2-Preisen und Laufzeitverlängerungen von bis zu 28 Jahren würden 25 Mrd. € oder mehr zusätzlich anfallen.
Langfristig erscheint fraglich, ob unter dem gegenwärtigen Marktdesign noch Anreize für Investitionen in fossile Kraftwerke gegeben sind. Zu Beginn der NAP 2-Periode noch rentable Investitionen in Braunkohle- und GuD-Kraftwerke werden mit der auslaufenden Gratiszuteilung von Emissionsrechten zunehmend unrentabler. Die Rentabilität wird durch Strommarkteffekte der erneuerbaren Energien und ausscheidender alter Gas- und Ölkraftwerke stetig weiter untergraben. Steinkohlekraftwerke erweisen sich selbst mit anfänglicher Gratiszuteilung als riskante Investition.
Die festgestellten Anreizprobleme für Neuinvestitionen sollten jedoch nicht dem Emissionshandel zugeschrieben werden, sondern resultieren aus den an Grenzkosten orientierten Strompreisen. Das Anreizproblem ist allerdings bei moderaten CO2-Preisen am größten. Es gilt auch für Kraftwerke mit CO2-Abscheidung: Obwohl die erwarteten Vermeidungskosten für CCS-Kraftwerke gegenüber konventionellen Kohlekraftwerken im Jahr 2025 auf 25 €/t CO2 (Braunkohle) bzw. 38,5 €/t CO2 (Steinkohle) geschätzt werden, wird ihr Bau erst ab CO2-Preisen von 50 bzw. 77 €/t CO2 rentabel.
Ob und welche Kraftwerksinvestitionen sich langfristig rechnen, wird letztlich aber politisch entschieden und ist selbst unter stark idealisierten Bedingungen kaum vorhersagbar. / Power plant investors face large uncertainties due to ongoing liberalization, climate policy, and long investment horizons. This study provides a probabilistic appraisal of power plant investments within the framework of Bayesian decision theory. A Bayesian influence diagram is used for setting up a discounted cash flow model and analysing the profitability of power plants. As the study explicitly models merit order pricing, the pass-through of random fuel and carbon costs may be analysed. The study derives probabilistic statements about net present values of single investments and company portfolios and explores the sensitivity of profits to variations of select input variables. In the majority of cases, an increase in the price of emission allowances also increases the net present value of existing power plant portfolios. A substantially increased carbon prices also is the prerequisite to diversify power plant portfolios by gas and CCS plants. For the currently prevailing German electricity market, we argue that investors may lack incentives for new investments in fossil generation, a finding that holds true also with implementation of CCS. Our estimates are conservative, as profitability will further deteriorate with the build-up of renewables.
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The voluntary appliction of the integrated environmental management guidelines by Eskom in KwaZulu-Natal, 1989 to 1997.Burger, Bruce Jonathan. January 2003 (has links)
The end of the last century saw a meteoric rise in Environmental Impact Assessment (EIA) and its implementation worldwide subsequent to it being legislated by the United States in 1970. The South African Government's Council for the Environment
attempted to emulate international developments in EIA and compiled the Integrated Environmental Management (IEM) guidelines of 1989 which delineated the procedure for undertaking EIAs for development projects in South Africa. It was envisaged that these guidelines would ultimately be made law. The period between 1989 and 1997 was a window period when the IEM guidelines were implemented voluntarily. This period therefore constitutes an important era in the history of EIA in South Africa to which constant reference is made and upon which further
development in EIA in South Africa has been reliant. The period 1989 to 1997 also coincided with a major increase in the bulk electricity supply to KwaZulu-Natal by Eskom, the national electricity utility. Eskom had actively tracked the evolution of Environmental Management globally and was considered to be at the forefront of Industrial Environmental Management in South
Africa and there was therefore an expectation that Eskom would implement the IEM guidelines. In this study twelve EIAs for Eskom powerlines and substations constructed in KZN for the period were analysed and trends in the implementation of the IEM guidelines extrapolated. This study highlights the extent to which the IEM guidelines were implemented. It discusses the problems attendant to its implementation, which were found to be common to the implementation of EIA globally. From this research it became clear that factors external to the IEM guidelines needed to be resolved before the IEM guidelines could be implemented. The administrative requirement was one of the most important and necessary requirements for successful implementation, but this had not been thoroughly anticipated by Eskom nor the guidelines themselves. This required that there was major reform to policy and company procedure, which had to be clearly understood and accepted, before IEM could be effectively implemented. As a consequence, the implementation of the various steps of the IEM guidelines seldom revealed consistent and satisfactory implementation. Even where the IEM guidelines were more closely followed and implemented, previously entrenched technocentrist procedures and ideals persisted and therefore IEM was subverted and implemented with the wrong goal in mind. There was also an expectation that there would be an improvement in EIA practice with time. It was found that there was a greater association between the quality of the EIA conducted and the Eskom Environmental Officer responsible for it, rather than a consistent improvement with time. Thus integration into the project process of environmental procedure is a complex process and it requires firstly that a company is reformed. Reform has subsequently begun to transpire in Eskom. This reform includes education of company employees, which in turn is linked to political will which is necessary to effect the changes required to apply a procedure such as the IEM guidelines. This study reviews the implementation of the IEM guidelines in Eskom during this important development phase. It therefore reflects on a key portion of the history of EIA implementation in this country. The study provides insight into organisational reform and the voluntary commitments required for successful implementation of EIA. Benefit can be drawn from this study for future implementation of EIA even though EIA legislation now exists, as some form of voluntariness, political will and
organisational reform is always imperative for ETA's successful and effective implementation. / Thesis (M.Sc.)-University of Natal, Durban, 2003.
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An assessment of the impact of the deregulation of the electric power sector in the U. S. on the efficiency of electricity generation and the level of emissions attributed to electricity generationSharabaroff, Alexander M. January 2008 (has links)
Thesis (M.S.)--Ohio University, June, 2008. / Title from PDF t.p. Includes bibliographical references.
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Método previsor-corretor primal-dual de pontos interiores em problemas multiobjetivo de despacho econômico e ambientalStanzani, Amélia de Lorena [UNESP] 22 August 2012 (has links) (PDF)
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stanzani_al_me_bauru.pdf: 1270169 bytes, checksum: 95427289f92cae68045965f775abae46 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O presente trabalho apresenta o método primal-dual previsor-corretor de pontos interiores para programação quadrática, com restrições lineares e quadráticos e variáveis canalizadas, e a aplicação deste método na resolução de problemas multiobjetivo de despacho econômico e ambiental, encontrados na engenharia elétrica. Pretende-se determinar soluções que sejam eficientes em relação ao custo dos combustíveis empregados na geração termoelétrica de energia e ao controle da emissão de poluentes, investigando-se duas estratégias: a primeira estratégica considera na função objetivo a soma ponderada entre as funções objetivo econômica e objetivo ambiental; a segunda estratégia considera o problema de despacho econômico condicionado à restrição ambiental, limitada superiormente para níveis permissíveis de missão. Para a resolução destes, uma implementação computacional do método primal-dual foi realizada em linguagem de programação C++, considerando o procedimento previsor-corretor com uma estratégia de barreira modificada para as restrições quadráticas de desigualdade, quando consideramos a segunda estratégia. Os resultados obtidos demonstram a eficiência do método em destaque em comparação a outros métodos como algoritmos genéticos co-evolutivo, atávico híbrido e cultural, bem como ao método primal-dual de pontos interiores, com procedimento de busca unidimensional, que estão divulgados na literatura / This paper presents the primal-dual predictor-corrector interior point method for quadratic programming with linear and quadratic constraints and bounded variables, and its application in multiobjective problems of economic and environmental dispatch, found in electrical engineering. It is intended to determine effective solutions to the fuel cost used in thermal power generation and emissions control, by investigating two strategy; the first strategy considers the objective function as weighted sum of economic and environmental objective functions; the second strategy considers the economic dispatch problem subject to environmental constraint, upper bounded for allowable emission levels. To solve them, a computational implementation of primal-dual methods was performed in C++ programming language, considering the predictor-corrector procedure with a strategy of modified barrier for the quadratic inequality constraints, when we considerer the second strategy. The results obtained demonstrate the efficiency of the method highlighted in comparison with the co-evolutive genetic algorithms, hybrid and atavistic cultural, as well the primal-dual interior point method with one-dimensional search procedure, which are found in the literature
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Development of models for short-term load forecasting using artificial neural networksAmakali, Simaneka January 2008 (has links)
Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Discipline Electrical Engineering
in the Faculty of Engineering
at the Cape Peninsula University of Technology
2008 / Optimal daily operation of electric power generating plants is very essential for any power utility
organization to reduce input costs and possibly the prices of electricity in general. For a fossil fuel –
fired power plant for example, the benefits of power generation optimalization (i.e. generate what is
reasonably required) extends even to environmental issues such as the subsequent reduction in air
pollution. Now to generate “what is reasonably required” one needs forecast the future electricity
demands. Because power generation relies heavily on the electricity demand, the consumers are also
practically speaking required to wisely manage their loads to consolidate the power utility’s optimal
power generation efforts. Thus, for both cases, accurate and reliable electric load forecasting systems
are absolutely required.
To date, there are numerous forecasting methods developed primarily for electric load forecasting.
Some of these forecasting techniques are conventional and often less favoured.
To get a broad picture of the problem at hand, a literature survey was first conducted to identify
possible drawbacks of the existing forecasting techniques including the conventional one. Artificial
neural networks (ANNs) approach for short-term load forecasting (STLF) has been recently proposed
by a majority of researchers. But there still is a need to find optimal neural network structures or
convenient training approach that would possibly improve the forecasting accuracy.
This thesis developed models for STLF using ANNs approach. The evolved models are intended to
be a basis for real forecasting application. These models are tested using actual load data of the Cape
Peninsula University of Technology (CPUT) Bellville campus reticulation network and weather data
to predict the load of the campus for one week in advance.
The models were divided into two classes: first, forecasting the load for a whole week at once was
evaluated, and then hourly models were studied. In both cases, the inclusion of weather data was
considered. The test results showed that the hour-by-hour approach is more suitable and efficient for
a forecasting application. The work suggests that incremental training approach of a neural network
model should be implemented for on-line testing application to acquire a universal final view on its
applicability.
Keywords – power system operations, load forecasting, artificial neural networks, training mode,
accuracy
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Synthesis of zeolites from South African coal fly ash: investigation of scale-up conditionsMainganye, Dakalo January 2012 (has links)
Thesis submitted in fulfilment of requirements for the degree
Magister Technologiae: Chemical Engineering
In the FACULTY OF ENGINEERING
At the CAPE PENINSULA UNIVERSITY OF TECHNOLOGY, 2012 / The generation of electricity from coal in South Africa results in millions of tons of fly ash being produced each year. Less than 10 % of the fly ash generated is being used constructively and the remaining unused ash is currently inducing disposal and environmental problems. Intensive research on the utilisation of fly ash has been conducted either to reduce the cost of disposal or to minimise its impact on the environment. It has been shown that South African fly ash can be used as a feedstock for zeolite synthesis due to its compositional dominance of aluminosilicate and silicate phases.
Most of the studies conducted on zeolite synthesis using South African fly ash are performed on small laboratory scale. Therefore, production of zeolites on an industrial/pilot plant scale would, in addition to producing a valuable product, help abate the pollution caused by the disposal of fly ash in the country. This research focuses on the investigation of the scale-up opportunity of zeolite synthesis from South African fly ashes with the view of understanding the effects of some reactor and operational parameters on the quality of the zeolite produced. Two types of zeolites (zeolite Na-P1 and zeolite A) were synthesised via two different routes in this study: (1) a two stage hydrothermal synthesis method (zeolite Na-P1) and (2) alkaline fusion prior to hydrothermal synthesis (zeolite A). The synthesis variables evaluated in this study were; the effect of impeller design and agitation rates during the aging step (zeolite Na-P1) using three different impellers (anchor, 4-flat-blade and Archimedes screw impeller) at three agitation speeds (150, 200 and 300 rpm), the effect of fly ash composition and solvents (water sources) on the phase purity of both zeolite Na-P1 and zeolite A, and the effect of the hydrothermal reaction time during the synthesis of zeolite Na-P1 using low amorphous phase fly ash i.e. aging time (12-48 hours) and hydrothermal treatment time (12-48 hours).
The raw materials (fly ashes from Arnot, Hendrina, Tutuka, Lethabo and Matla power stations) and the synthesised zeolite product were characterised chemically, mineralogically and morphologically by X-ray fluorescence spectrometry, X-ray powder diffraction and scanning electron microscopy. Other characterisation techniques used in the study were 1) Fourier transform infrared spectroscopy to provide structural information and also monitor the evolution of the zeolite crystals during synthesis and 2) inductively coupled plasma atomic emission (ICP-AES) and mass spectrometry for multi-elemental analysis of the synthesis solution and the solvents used in this study.
The experimental results demonstrated that the phase purity of zeolite Na-P1 was strongly affected by agitation and the type of impeller used during the aging step of the synthesis
process. A high crystalline zeolite Na-P1 was obtained with a 4-flat-blade impeller at a low agitation rate of 200 rpm. Although a pure phase of zeolite Na-P1 was obtained at low agitation rates, the variation in the mineralogy of the fly ash was found to affect the quality of the zeolite produced significantly. The results suggested that each batch of fly ash would require a separate optimisation process of the synthesis conditions. Therefore, there is a need to develop a database of the synthesis conditions for zeolite Na-P1 based on the fly ash composition. As a consequence, the scale-up synthesis of zeolite Na-P1 would require step-by-step optimisation of the synthesis conditions, since this zeolite was sensitive to the SiO2/Al2O3 ratio, agitation and the mineralogy of the fly ash.
On the other hand, zeolite A synthesis had several advantages over zeolite Na-P1. The results suggested that a pure phase of zeolite A can be produced at very low reaction temperature (i.e. below 100 °C, compared to 140 °C for zeolite Na-P1), shorter reaction times (i.e. less than 8 hours compared to 4 days for zeolite Na-P1), with complete dissolution of fly ash phases and more importantly less sensitive to the SiO2/Al2O3 ratio of the raw materials. The zeolite A synthesis process was found to be more robust and as a result, it would be less rigorous to scale-up despite the energy requirements for fusion.
This study showed for the first time that different impeller designs and agitation during the aging step can have a profound impact on the quality of the zeolite produced. Therefore, it is not only the hydrothermal synthesis conditions and the molar regime but also the dissolution kinetics of the feedstock that influence the outcome of the zeolite synthesis process. This study has also shown for the first time that a pure phase of zeolite A can be synthesised from various sources of South African fly ash containing different mineralogical and chemical compositions via the alkali fusion method under the same synthesis conditions. Therefore, the effective zeolitisation of fly ash on a large scale would assist to mitigate the depletion of resources and environmental problems caused by the disposal of fly ash.
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Sistema de conexão de mini e micro centrais hidrelétricas às redes monofásicas das concessionáriasBertoncello, Ricardo 19 August 2011 (has links)
Este trabalho tem por objetivo desenvolver um sistema de conexão entre unidades de geração trifásica e uma rede de distribuição de energia elétrica rural monofásica. O sistema proposto baseia-se em um conversor CA/CA. Este conversor é composto por um retificador trifásico modulado por largura de pulso e um inversor monofásico. O controle do sistema é realizado através de um controlador digital de sinais (DSC). Atualmente o custo para conexão de mini e micro centrais hidrelétricas às redes de distribuição das concessionárias é bastante elevado, principalmente pelo custo de implantação das redes de distribuição trifásicas, e isso gera impacto principalmente nos pequenos empreendimentos. Para os empreendimentos maiores, este custo é diluído no custo total da obra, não impactando de forma significativa na viabilidade do negócio. Este trabalho visa desenvolver um sistema de conexão que atenda os requisitos técnicos e as exigências legais e que ao mesmo tempo consiga reduzir os custos para a conexão de pequenos agentes geradores no sistema elétrico nacional, em localidades onde somente a rede monofásica esteja disponível. Com isso, pretende-se viabilizar economicamente a inserção de pequenos produtores no cenário de geração e comercialização de energia elétrica. / The objective of this work is to develop a connection system between three-phase generation units and a single phase rural distribution electricity network. The proposed system is based on an AC/AC converter. This converter consists in a threephase PWM rectifier and a single-phase PWM inverter. System control is performed by a Digital Signal Controller (DSC). Currently, the cost for connecting mini and micro hydropower plants to distribution networks of utilities is very high, especially because of the three phase distribution networks deployment cost, which generates impact mainly in small businesses. For larger businesses, this cost is diluted within the total work costs, not significantly impacting business viability though. This work aims at developing a system that meets the technical and legal connection requirements and, at the same time, will be capable of reducing costs for connecting small generating agents in the national power system in locations where only a single-phase network is available. Therefore, we intend to make economically viable insertion of small producers in the generation and sale electricity scenario.
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Análise da viabilidade da implantação de um sistema híbrido para geração de energia elétricaZanoni, Naubert 29 March 2018 (has links)
Sistemas híbridos consistem de duas ou mais fontes geradoras de eletricidade, normalmente uma ou mais fontes convencionais e uma ou mais fontes renováveis e, objetivam promover a economia de combustível e obter uma fonte confiável de suprimento de energia, podendo estar ou não conectados a rede de distribuição. Este trabalho objetiva avaliar através do software HOMER, a viabilidade técnica, econômica e ambiental de implantação de um sistema híbrido de geração de eletricidade. Este sistema é composto por gerador movido a biogás, gerador movido a biodiesel e captação de energia solar. Todo o sistema está localizado no município de Serafina Corrêa onde há elevada concentração de suinocultores que, através do tratamento dos resíduos suinícolas poderá levar a produção de biogás para ser aproveitado como combustível para geração de energia elétrica. Diversas configurações foram avaliadas sob aspecto econômico e ambiental. A configuração ótima da estrutura do sistema híbrido foi a composta por geração elétrica a partir de painéis fotovoltaicos com 172,4 kW, gerador a biogás 55 kW e inversor de frequência de 110 kW. Neste cenário, o capital inicial soma R$ 1.150.055,00, valor presente líquido de R$ 1.150.004,00 e o custo da energia (COE) é de R$ 0,22/kW. O payback definido pelo software é de 7,1 anos, mostrando-se economicamente viável. Neste contexto, o software HOMER apresenta-se como importante ferramenta a tomada de decisões configurando-se como método de avaliação quanto ao melhor cenário para instalação de sistemas híbridos. / Hybrid systems consist of two or more electricity generating sources, usually one or more conventional sources and one or more renewable sources, and aim to promote fuel economy and obtain a reliable source of energy supply, off-grid or grid-connected to the distribution network. This work aims to evaluate through the HOMER software the technical, economic and environmental feasibility of implementing a hybrid electricity generation system. This system consists of a biogas generator, biodiesel generator and solar energy capture. The entire system is located in the municipality of Serafina Corrêa where there is a high concentration of swine farmers that, through the treatment of pig waste, can lead to the production of biogas to be used as fuel for electric power generation. Several configurations were evaluated under economic and environmental aspect. The optimum configuration of the hybrid system structure is composed of electric generation from photovoltaic panels with 172,4 kW, 55 kW biogas generator and 110 kW inverter. In this scenario, the initial capital amounts to R$ 1.150.055,00, net present value of R$ 1.150.004,00 and the cost of energy (COE) is R$ 0.22. The payback defined by the software is 7.1 years, proving to be economically viable. In this context, the HOMER software presents itself as an important decision-making tool, being configured as an evaluation method for the best scenario for the installation of hybrid systems.
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