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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Determinantes EconÃmicas do Consumo de Energia ElÃtrica no Estado do Cearà / Determinative Economic of Consumo de Electric Energia in the State of the CearÃ

Luiz Antonio Trotta Miranda 16 April 2004 (has links)
O aumento do consumo de energia elÃtrica à considerado uma das condiÃÃes bÃsicas para o desenvolvimento econÃmico de um paÃs. O Brasil, nos Ãltimos anos, tem apresentado significativos aumentos em seu consumo de energia elÃtrica, e o Governo Federal nÃo dispÃe de recursos para investir adequadamente no setor. Assim sendo, o paÃs està passando por profundas modificaÃÃes em sua estrutura energÃtica, buscando adequarse para garantir o futuro do setor. Conhecer bem a demanda de energia elÃtrica, atravÃs de anÃlises economÃtricas, à de fundamental importÃncia para possibilitar que investidores privados supram a deficiÃncia de investimentos do setor pÃblico. Esse trabalho utilizarà modelos economÃtricos, pelo mÃtodo dos mÃnimos quadrados e pelo mÃtodo dos mÃnimos quadrados em dois estÃgios para sugerir modelos que expliquem o consumo de energia elÃtrica no Estado do CearÃ. Para as anÃlises, foram considerados como variÃveis independentes o nÃmero de domicÃlios do Estado do CearÃ, o PIB do Estado do Cearà e do Brasil, a tarifa mÃdia de energia brasileira, o consumo de energia elÃtrica do Brasil e uma variÃvel qualitativa dummy. Foram feitos 07 diferentes modelos utilizando o MÃtodo dos MÃnimos Quadrados e 02 modelos utilizando o MÃtodo dos MÃnimos Quadrados em Dois EstÃgios. Cada modelo foi analisado individualmente. Algumas variÃveis que inicialmente acreditava-se terem alta representatividade no consumo de energia elÃtrica, como por exemplo a tarifa de energia elÃtrica, demonstraram-se pouco significativas em diversos modelos, enquanto que outras, como por exemplo o nÃmero de domicÃlios, apresentaram alta significÃncia nos modelos. Por esse motivo, optou-se por fazer diversos modelos, permitindo com isso analisar a interaÃÃo das diversas variÃveis. Para o mÃtodo dos mÃnimos quadrados em dois estÃgios, considerou-se como endÃgenas as variÃveis PIB do Estado do Cearà e o Consumo de Energia ElÃtrica do Estado do CearÃ. / The increase of electric power consumption is considered one of the basic conditions for the economic growth of any country. Brazil, in the last years, has presented significant increases in its supply/demand of electric power, in spite of the Federal Government having lack of financial resources to invest adequately in this sector. Nevertheless, the country has experienced sharp modifications in its energy structure, trying to adjust itself to guarantee the future of the sector and sustain the country growth. To properly know how to estimate the demand for electric power, through econometrical analyses, it is to be considered of high importance to a country or a region development. It allows private investor to supply the deficiency of investments of the public sector. This work will use several econometrical models, by the method of the least square and the method of the two stages least square to suggest models that explain the consumption path of electric power in the State of the Cearà The econometric analyses considered, as independent variables: the number of domiciles of the State of CearÃ, the GGP of the State of Cearà and Brazil, the average Brazilian energy tariffs, the Brazilian electric power consumption, and a qualitative dummy variable. It was done 07 different models using the least square method and 02 models using the two stages least square method. Each model was then individually analyzed. Some variables that initially were given credit to have high representation in the power consumption of the state, as for example the tariffs of electric power, had been demonstrated during the work little significance in many models, while others, such as the number of domiciles, had showed high significance in the models. Thatâs the main reason why it was opted to make a large variety of models, allowing to analyze the interaction of all the variables. For the method of the two stages least square, it was considered as endogenous variables the GGP of the State of the Cearà and consumption de electric power of the State of CearÃ.
42

The water-energy nexus : a comprehensive analysis in the context of New South Wales.

Marsh, Debborah January 2008 (has links)
Water and electricity are fundamentally linked. Policy reforms in both industries, however, do not appear to acknowledge the links nor consider their wider implications. This is clearly unhelpful, particularly as policy makers attempt to develop effective responses to water and energy issues, underpinned by prevailing drought conditions and impending climate change. Against this backdrop, this research has comprehensively analysed the links between water and electricity – termed water-energy nexus – in the context of New South Wales. For this purpose, this research has developed an integrated methodological framework. The philosophical guidance for the development of this framework is provided by Integral Theory, and its analytical foundations rest on a suite of research methods including historical analysis, inputoutput analysis, analysis of price elasticities, and long-term scenario analysis. This research suggests that the historical and inextricable links between water and electricity, in the absence of integrated policies, has given rise to water-energy trade-offs. In the electricity industry, water-intensive coal-fired power stations that dominate base-load capacity in the National Electricity Market has resulted in intra- and inter-jurisdictional water sharing tradeoffs. Intermediate and peak demand technologies, suchas gas-fired, cogeneration and renewables, however, would significantly reduce the industry’s water consumption and carbon emissions. Drought and climate change adaptation responses in the water industry are likely to further increase electricity demand andpotentially contribute to climate change, due to policies that encourage investment in energy-intensive technologies, such as desalination, advanced wastewater treatment and rainwater tanks. Increasing electricity costs due to water shortages and the introduction of emissions trading will futher increase water and electricity prices for end users. Demand management strategies in both industries will assist in curbing price increases, however, their effectiveness is lessened by investment in water- and energy-intensive technologies in both industries. The analysis also demonstrates that strategies to reduce water and electricity consumption of ‘other’ production sectors in New South Wales is overwhelmingly dependent on how deeply a particular sector is embedded in the economy, in terms of its contribution to economic output, income generation and employment growth. Regulation, demand management programs, and water pricing policies, for example, that reduce the water and energy intensity of agriculture and key manufacturing sectors are likely to benefit the wider economy and the Environment. The future implications of the water-energy nexus are examined through long-term scenario analysis for New South Wales for 2031. The analysis demonstrates how policy decisions shape the domain for making philosophical choices by society - in terms of the balance between relying on alternative technologies and market arrangements, with differing implications for water and electricity use, and for instigating behavioural change. Based on these findings, this research puts forward a range of recommendations, essentially arguing for reorienting existing institutional arrangements, government measures and industry activities in a way that would encourage integration between the water and energy policies. Although the context of this research is New South Wales, the findings are equally relevant for other Australian states, which share the same national water and energy policy frameworks. Further, the concepts and frameworks developed in this research are also of value to other countries and regions that are faced with the task of designing appropriate policy responses to redress their water and energy challenges.
43

Collaborative environmental management in the Pearl River Delta : an urban operation research approach for electricity consumption

Zhang, Yingxuan, 張映璇 January 2014 (has links)
Electricity generation is the major emission source of air pollutants in the highly industrialized Pearl River Delta Region. In a compact region like the Pearl River Delta, pollutants can easily transfer from one city to another. The research question of this study is to construct an optimal and mutual agreeable scheme to reduce electricity consumption in the Pearl River Delta Region, which involves the collaboration of all cities in the Region. The main objective of the study is to conduct a cooperative scheme that internalizes the external social cost of electricity consumption through optimal electricity consumption reduction. This research first surveys papers on urban environmental problems, especially environmental problems caused in Pearl River Delta Region. Literature review indicates that public electricity generation is the major emission source of air pollutants in this region. Secondly, this research reviews literatures on the social costs of electricity consumption. Reviews show that external costs of electricity consumption in different countries differ widely, ranging from 13% to 700% of electricity price. This study adopts the lower quartile of this range, which is 13% of electricity price. Thirdly, urban operations research is reviewed, and a major policy instrument for environmental improvement, environmental tax, is investigated. This study develops a hierarchical structure of urban operations research to study the collaborative management of electricity consumption reduction in the Pearl River Delta Region. This urban operations research model includes seven essential steps: problem definition; objectives identification; performance measures; data analysis; analytical framework construction; model solution and courses of actions; and policy implementation. Moreover, this novel urban operations research model is applied in collaborative management of electricity consumption reduction in the Pearl River Delta. This research uses statistical and mathematical methods to estimate the parameters relevant to GDP, electricity consumption, external costs of electricity consumption, and environmental tax, and then formulates the operational model. Then, this model is employed to evaluate non-cooperative equilibrium condition among the eleven Pearl River Delta cities under a non-cooperative market outcome; to derive individual city’s external cost of electricity; to derive environmental levy and optimal electricity consumption reduction; and to design a compensation plan. In the compensation plan, under cooperation, in both 2013 and 2014, four cities (Guangzhou, Shenzhen, Foshan, and Dongguan) have to pay for their net spillover external cost of electricity consumption. The other seven cities (Zhuhai, Jiangmen, Huizhou, Zhaoqing, Hong Kong, Macao, and Zhongshan) would receive compensation. The urban operations research model for regional cooperation in electricity consumption reduction developed in this study provides an instrument to deal with the pollution problem in the Pearl River Delta Region. It facilitates the exploration of hitherto intractable problems in regional environmental cooperation and established solution plans. The urban operations model is expected to provide practical policy choices for a Pearl River Delta environmental collaboration scheme. This research represents the first attempt on an application of urban operations research model of collaborative management scheme of electricity consumption reduction in Pearl River Delta Region. / published_or_final_version / Urban Planning and Design / Doctoral / Doctor of Philosophy
44

Derivation and applications of optimum bus incremental costs

Ponrajah, Ranendra Anthony. January 1984 (has links)
No description available.
45

Test bed system for investigating the energy usage of variable speed drive systems.

Walker, Myles Larcome. January 2001 (has links)
As South Africa's electricity consumption increases, Eskom is promoting Demand Side Management (DSM) to aid control of both the electricity consumption and its more effective usage, thereby delaying the need to construct new power stations, which pose large economic and environmental problems. Eskom has investigated various DSM strategies, such as load shifting, co-generation, alternative fuels and energy efficient processes, and has targeted the areas of load shifting and energy efficiency as prime areas for energy savings as they are relatively inexpensive and easy to implement. Pumps and fans form a large part of the industrial load. By improving the power usage of these devices with the use of variable speed drives, large energy savings may be achieved. To enable the energy usage of industrial loads to be evaluated, a test bed system which enables a variable speed drive to be loaded with a configurable load, was constructed. The test bed system forms a tool for evaluating and demonstrating the energy savings that are possible, by replacing fixed speed drives with variable speed drives when controlling the flow rate of pumps and fans. Results from the test bed system show that by using variable speed operation of pumps and fans, some energy savings are achievable when compared to existing methods of flow control. The achievable energy savings are dependent on the system properties and the duty cycle of the pump or fan system. / Thesis (M.Sc.)-University of Natal, Durban, 2001.
46

An investigation into the power consumption efficiency at a base metal refinery.

Du Toit, Alzaan. 01 November 2013 (has links)
The addressed topic is to investigate the power distribution at a base metal refinery and to identify the potential improvement in power consumption efficiency. The work included in this study revealed that the power consumption efficiency at the evaluated base metal refinery can be improved. The significance of this study relates to Eskom’s tariff increases and directive to mining and large industrial companies to reduce their power consumption as well as the recent incremental increase in power tariffs. Base metal refineries are substantial power consumers and will be required to evaluate the efficiency of their base metal production. A load study was conducted at a base metal refinery in order to determine the current power consumption at the various process areas. The measurements obtained from the load study formed the basis for calculations to determine the potential efficiency improvement. The load study revealed that the electro-winning area contributes to the majority of the power consumed (52% of total apparent power) at the refinery. The potential improvement in efficiency at the electro-winning process area was identified by means of evaluating the rectifier and rectifier transformer power consumption. Methods and technologies for the reduction in power consumption was consequently evaluated and quantified. The potential reduction in conductor losses by converting from global power factor correction to localised power factor correction for the major plant areas was furthermore identified as an area of potential efficiency improvement and consequently evaluated. The improvement in motor efficiency across the base metal refinery was identified by means of comparing the efficiency and power factor of high efficiency motors to that of the standard efficiency motors installed at the refinery. The work included in this study reveals that an improvement in power consumption efficiency is achievable at the evaluated base metal refinery. An efficiency improvement of 1.785% (real power reduction of 2.07%) can be achieved by implementing localised power factor correction and high efficiency motors. An average efficiency improvement of 1.282% (total real power reduction of 2.78%) can be achieved with the additional implementation of specialised, high efficiency rectifier transformer designs. The implementation of localised power factor correction as well as high efficiency motors was identified as short term efficiency improvement projects. A financial study was conducted in order to determine the cost and payback period associated with the reduction in real power consumption for implementation of the recommended efficiency improvement projects. The payback period, required to achieve an average efficiency improvement of 1.785%, was calculated to be approximately 4 years. The initial capital investment required to implement the efficiency improvement projects is about R22.5 million. The monthly electricity utility bill savings associated with the efficiency improvement projects is approximately R455,000. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, Durban, 2012.
47

The free basic electricity policy : a case study of policy implementation in the Msunduzi Municipality.

Chetty, Indrasen. January 2006 (has links)
No abstract available. / Thesis (M.A.)-University of KwaZulu-Natal, Pietermaritzburg, 2006.
48

Consumer response to power conservation program.

Ramnarain, Veer Nishaan. January 2009 (has links)
In January 2008 the South African power grid operated by Eskom became severely constrained because electricity demand exceeded supply. Following the immediate measure of load shedding, Eskom implemented a medium term strategy of Power Conservation to encourage consumers to reduce their power usage so that overall demand could be managed. Despite the extensive campaigns the 10% electricity savings target was not met in 2008. The aim of this study was to review the experiences of other countries that had successfully implemented Power Conservation Programmes and to research the different approaches that were taken in other countries to encourage behaviour change. A survey and quantitative analysis was undertaken on a sample of electricity consumers within the eThekwini Municipality Central Region to gauge the response of consumers to the power conservation campaigns conducted within the municipality. The analysis was done to determine how the response had varied among the various groups by taking into account demographic factors like age, gender and income level. The population of the sample frame was estimated at 15 000 customers. Two hundred and eighty responses were received and analysed. A salient finding of the study was that the majority of respondents were aware of the reasons for power conservation and the campaigns undertaken, but that there was a preference for Government to lead the initiative and subsidise the required savings measures. A second important finding was that different demographic groups implemented different savings measures, for different reasons and preferred different strategies to encourage savings. The main recommendations made were that Government should lead the savings drive, with customised campaigns for different demographic groups. The campaigns should place greater emphasis on the financial benefits to be gained. It was necessary for new and different savings measures to be communicated. Further, the was a need for Government to introduce legislation to enforce electricity savings. / Thesis (MBA)-University of KwaZulu-Natal, Westville, 2009.
49

Advanced classification and identification of plugged-in electric loads

Du, Liang 13 January 2014 (has links)
The total electricity consumption of plugged-in electric loads (PELs) currently accounts for more usage than any other single end-use service in residential and commercial buildings. Compared with other categories of electric loads, PELs possess significant potential to be efficiently controlled and managed in buildings. Therefore, accurate and reliable PEL identification methods that are used to collect identity and performance information are desired for many purposes. However, few existing electric load identification methods are designed for PELs to handle unique challenges such as the diversity within each type of PEL and similarity between different types of PELs equipped by similar front-end power supply units. The objective of this dissertation is to develop non-intrusive, accurate, robust, and applicable PEL identification algorithms utilizing voltage and current measurements. Based on the literature review of almost all existing features that describe electric loads and five types of existing methods for electric load identification, a two-level framework for PELs classification and identification is proposed. First, the supervised self-organizing map (SSOM) is adopted to classify a large number of PELs of different models and brands into several groups by their inherent similarities. Therefore, PELs with similar front-end power supply units or characteristics fall into the same group. The partitioned groups are verified by their power supply unit topology. That is, different groups should have different topologies. This dissertation proposes a novel combination of the SSOM framework and the Bayesian framework. Such a hybrid identifier can provide the probability of an unknown PEL belonging to a specific type of load. Within each classified group by the SSOM, both static and dynamic methods are proposed to distinguish PELs with similar characteristics. Static methods extract steady-state features from the voltage and current waveforms to train different computational intelligence algorithms such as the SSOM itself and the support vector machine (SVM). An unknown PEL is then presented to the trained algorithm for identification. In contrast to static methods, dynamic methods take into consideration the dynamics of long-term (minutes instead of milliseconds) waveforms of PELs and extract elements such as spikes, oscillations, steady-state operations, as well as similarly repeated patterns.
50

The water-energy nexus : a comprehensive analysis in the context of New South Wales.

Marsh, Debborah January 2008 (has links)
Water and electricity are fundamentally linked. Policy reforms in both industries, however, do not appear to acknowledge the links nor consider their wider implications. This is clearly unhelpful, particularly as policy makers attempt to develop effective responses to water and energy issues, underpinned by prevailing drought conditions and impending climate change. Against this backdrop, this research has comprehensively analysed the links between water and electricity – termed water-energy nexus – in the context of New South Wales. For this purpose, this research has developed an integrated methodological framework. The philosophical guidance for the development of this framework is provided by Integral Theory, and its analytical foundations rest on a suite of research methods including historical analysis, inputoutput analysis, analysis of price elasticities, and long-term scenario analysis. This research suggests that the historical and inextricable links between water and electricity, in the absence of integrated policies, has given rise to water-energy trade-offs. In the electricity industry, water-intensive coal-fired power stations that dominate base-load capacity in the National Electricity Market has resulted in intra- and inter-jurisdictional water sharing tradeoffs. Intermediate and peak demand technologies, suchas gas-fired, cogeneration and renewables, however, would significantly reduce the industry’s water consumption and carbon emissions. Drought and climate change adaptation responses in the water industry are likely to further increase electricity demand andpotentially contribute to climate change, due to policies that encourage investment in energy-intensive technologies, such as desalination, advanced wastewater treatment and rainwater tanks. Increasing electricity costs due to water shortages and the introduction of emissions trading will futher increase water and electricity prices for end users. Demand management strategies in both industries will assist in curbing price increases, however, their effectiveness is lessened by investment in water- and energy-intensive technologies in both industries. The analysis also demonstrates that strategies to reduce water and electricity consumption of ‘other’ production sectors in New South Wales is overwhelmingly dependent on how deeply a particular sector is embedded in the economy, in terms of its contribution to economic output, income generation and employment growth. Regulation, demand management programs, and water pricing policies, for example, that reduce the water and energy intensity of agriculture and key manufacturing sectors are likely to benefit the wider economy and the Environment. The future implications of the water-energy nexus are examined through long-term scenario analysis for New South Wales for 2031. The analysis demonstrates how policy decisions shape the domain for making philosophical choices by society - in terms of the balance between relying on alternative technologies and market arrangements, with differing implications for water and electricity use, and for instigating behavioural change. Based on these findings, this research puts forward a range of recommendations, essentially arguing for reorienting existing institutional arrangements, government measures and industry activities in a way that would encourage integration between the water and energy policies. Although the context of this research is New South Wales, the findings are equally relevant for other Australian states, which share the same national water and energy policy frameworks. Further, the concepts and frameworks developed in this research are also of value to other countries and regions that are faced with the task of designing appropriate policy responses to redress their water and energy challenges.

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