Thesis submitted in partial fulfilment of the requirements for the degree Magister Technologiae: Electrical Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology 2008 / Fuel cell technology is an emerging technology that provides a highly efficient, quiet operation, reliable, and environmentally friendly energy conversion system for stationary, automobile (vehicle), and portable applications. An electrochemical process combines hydrogen fuel and oxygen from air to produce water, and in the process it produces electricity and heat. Fuel cell stationary applications which include residential, office buildings, hospitals, hotels, airports and others have received greater attention for their ability to utilize the heat generated for space and water heating. This combined heat and power (CHP) process increases the energy conversion efficiency greatly which in turn save cost of energy usage. Different power converter topologies for fuel cell systems residential applications are presented in this thesis for efficiency, cost, component count, input ripple current minimization technique, reliability for comparison analysis. The commercial feasibility of fuel cells rests on the cost of the fuel cell system and operating efficiency and fuel cost. The proposed power converter topology consists of two front end DC-DC converters. The first front-end DC-Dc converter is tightly controlled while the second is a full bridge four interleaved DC-DC converters. Advantages of the proposed topology are reduced input ripple current, high efficiency, low maintenance cost, smaller size, modularity, redundancy. Design overview as well as simulation results are presented. Fuel cell simulation test results, including transient response are displayed and analyzed. The concept of interleaving of multiple units of the De-De converter is proposed. Interleaving enables paralleling multiple units of the converters to achieve a high combined power. This results in using semiconductor power devices of lower current rating, lowering sizes of input and output capacitors and reducing the output ripples. Simulations results are presented that verify the concept of interleaving. Preliminary work to implement interleaving is presented, and future work is recommended.

Thesis (MTech (Electrical Engineering))--Cape Peninsula University of Technology, 2011. / Initiatives that are directed towards improving power management by a utility provider have to consider technical feasibility, socio-economic and the environment. Patterns of power consumption world over indicate that demand for electricity has over the years been on the rise due to increase in activities that demand usage of electricity. Such activities include construction and property development, development of industries and infrastructure. These activities have strained the power production, whose development does not match the increase in demand. ESKOM, a government authority mandated to generate, transmit and distribute power in South Africa has seen demand surpassing its generation capacity, hence resorting to load shedding actions. Load shedding imposes inconveniences to the consumers who are completely disconnected from the grid, translating to unpredictable periods of darkness. Utility providers have an option of constructing new peaker plants which lie idle most of the day, to take care of high demand during the peak periods, hence, avoid effecting load shedding actions. Various ways of managing load have been presented in this research. In particular, the research investigated possible ways utilities use in managing their capacity with an aim of developing an alternative method and tool for Demand Side Management applications that can be used by energy utility to improve reliability, manage and control consumption of electrical energy through selective shedding of the load connected to the consumer when the demand surpasses the utility's safe capacity.

Atualmente, diante dos possíveis riscos de falta no fornecimento de energia elétrica no Brasil, surge a necessidade de se educar os consumidores a utilizar corretamente a energia elétrica, pois é mais barato conservar energia do que produzi-Ia. Na busca de solucionar a má utilização da energia elétrica em um campus universitário, levantam-se as características da instalação existente por meio de um equipamento registrador/medidor de grandezas elétricas. De posse destes dados, descrevem-se os problemas de consumo e de dimensionamento dos equipamentos encontrados nas instalações internas, a fim de se apontarem soluções técnicas viáveis para que se possa ter o uso racional de energia elétrica, as quais também poderão ser utilizadas em quaisquer outros centros consumidores. Além disto, abordam-se aspectos relativos ao gerenciamento das instalações existentes, visando-se o correto uso da energia elétrica, independentemente das condições em que se encontram as instalações. E dentro do possível, analisam-se as medidas sugeridas, o que demonstra a viabilidade das mudanças, frente à manutenção dos gastos existentes. / Due to the current possible risks to electric energy supply in Brazil, there is the need of making the consumers aware of how to use electric energy correctly, because it is cheaper to conserve energy than to produce it. Seeking to correct the use of electric energy in a university campus, characteristics of the existent installation were researched by means of recording/measuring equipment of electric variables. With this data provided is described the problems of consumption and use of the equipment found in the intemal facilities, with the purpose of aiming at viable technical solutions as to the rational use of electric energy, not only locally but in any other consumer centers. Furthermore, some aspects related to the management of the existent facilities were approached with a view to using electric energy correctly, independently of the conditions which of facilities are met. Suggested measures are analyzed for the sake of evaluating the viability the proposed changes, with regard to the maintenance of the existent expenses.

Esta dissertação apresenta o estudo para determinação da redução da potência no chuveiro elétrico quando da utilização da base recuperadora de calor. Ainda, compara os resultados de duas metodologias de avaliação dos ganhos energéticos, em acordo ao estabelecido no Protocolo Internacional de Medição e Verificação de Performance (PIMVP), para as ações de troca de chuveiros nas comunidades de baixa renda. A aplicação da proposta comprovou que os resultados de redução de potência para o conjunto chuveiro mais base recuperadora podem ser extrapolados para toda a população que recebe a ação de eficiência energética. Mostrou que as estimativas para o fator de coincidência no período da ponta, que traduzem a utilização do chuveiro, constituem elemento decisivo na determinação da potência retirada no período da ponta. Por fim, a opção de medição e verificação baseada na opção “B” do referido protocolo é mais conservativa e mais assertiva na determinação dos resultados da potência retirada no período da ponta. / This dissertation presents a study to determine the power reduction in electric shower when using the heat recovery base. Also, compare the results of two methods of assessing the energy savings in accordance to the provisions of Protocol International Performance Measurement and Verification (IPMVP) for the exchange of shares of showers in low-income communities. The implementation of the proposal showed that the results of power reduction for the whole shower over recuperative base can be extrapolated to the entire population that receives the action of energy efficiency. Showed that the estimates for the coincidence factor at the period, which reflect the use of the shower, constitute decisive factor in determining the power drawn at the period. Finally, the choice of measurement and verification based on the "B" option is more conservative and more assertive in determining the outcomes of power drawn from the period.

Orientador: Roger Josef Zem / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T09:22:00Z (GMT). No. of bitstreams: 1 Santana_ElaineIsaSantosde_D.pdf: 517402 bytes, checksum: 28c8b7fd37a03b754bba71fbee94a2c9 (MD5) Previous issue date: 2004 / Resumo: Nos dias atuais, um grande desafio das indústrias é conciliar a produção com os padrões de qualidade exigidos pelo mercado e o mínimo consumo energético. Em uma unidade industrial, a coluna de destilação é uma das operações unitárias que mais consome energia e freqüentemente aparece em maior número. Conseguir otimizar a utilização das fontes de energia é primordial para reduzir significativamente os custos da produção. A proposta desta tese é estudar o projeto de um sistema de separação complexo (coluna de para fracionamento de petróleo), aplicando abordagem termodinâmica: o estudo foi realizado através dos perfis termodinâmicos construídos com os resultados de simulação. A análise conjunta da GCCC (Dhole e Linnhoff, 1992) e do perfil de perdas exergéticas (Zemp, 1994) sugere modificações atrativas, do ponto de vista energético, tanto para o projeto de colunas quanto para a ampliação de capacidade de colunas em operação. Os ganhos alcançados propiciam um menor consumo de energia e custo operacional e reduz a poluição ambiental. A utilização de abordagem termo dinâmica na otimização de uma coluna de destilação precisa de um tratamento inicial nos resultados para obter os perfis termodinâmicos (composição da alimentação e produtos, temperatura e composição de cada estágio, entalpia e entropia para cada fase nos estágios). Entretanto a metodologia termodinâmica é de fácil aplicação, uma vez que os perfis gerados descrevem as oportunidades de ganhos que são revertidos em redução de custos. Durante o trabalho foi desenvolvido um programa específico para a construção dos perfis termodinâmicos (ProAt.exe) que auxiliou na avaliação dos vários casos de melhoria sugeridos. O grande diferencial entre o uso das metodologias de Análise Pinch e Análise Exergética e os métodos convencionais de otimização é a redução do esforço computacional e matemático. A utilização de dados de uma simulação convergida, que já consideram irreversibilidades do sistema, e as 1 a e 2a Leis da Termodinâmica tornam as met9dologias propostas para otimização eficientes e menos complexas / Abstract: Nowadays an industry's challenge is to combine production with high quality ordered by the clients and minimum energetic comsuption. Fractionation column is one of the operations that uses energy and often appears in large number in industry' s units. Optimize the energy source consumptions is primordial to reduce the production costs. The thesis proposal is study a design of a complex fractionation system (petroleum fractionation column) applying thermodynamic approach: the study was realized using thermodymanic profiles built with simulation results. The combined analysis of Grand Composite Curve of the Column (Dhole and Linnhoff, 1992) and Exergy Losses Profile (Zemp, 1994) suggests interesting modifications in energetic concem to column designs and retrofit. The obtaineq gains result in low energy consumption and production costs and reduce the environmental pollution. The application ofthermodynamic approach in otimization of a fractionation column needs .a inicial treatment ofthe results to obtain the thermodynamic profiles (feed and products composition, stage temperatures and composition, enthalpy and entropy for each stage phases). However the thermodynamic approach is applicable because the generated profiles shows the opportunities of gains that are compared of cost reduction. During this thesis a specific program was developed to generate the thermodynamic profiles (ProAt.exe) that helped in the evaluation of many improvement cases. The most important difference between the use of Pinch and Exergetic Analysis and the conventional approachs of otimization is the reduction of comput~cional and mathematical effort. The use of converged simulation that considers some irreversibilities of the system and the application of 1 st and 2nd Thermodymanic Laws become the proposal approaches eficient and less complex / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

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The continuous turmoil in some regions of the Middle East, including Syria and Iraq, has resulted in the displacement of millions of people, a big portion of those displaced people end up seeking refuge in neighboring countries, where often refugee camps are set up by multiple contributors for humanitarian causes. The infill form of planning that comes with an emergency situation such as war, does not optimize the individual, social and energy efficiency aspects of refugee camps. Looking at the various refugee camps around the world gives an insight on how to/ or not to design in relation to climatic conditions. Lessons learned can also be deducted from looking at established camps and social programs. The goal is to design a grouping of Green shelters that allows for individual wellbeing and social interaction alongside the rest of the basic human needs.

Purpose: There is a worldwide movement towards sustainability. A stepping-stone towards a sustainability conscience population starts in the education of the younger generation. Focusing on improving sustainability education will shift and shape youths' interests and lifestyles into an educated community that will work sustainably. A sustainability conscience community will continue to make moral sustainable decisions in their future endeavors. The gap between theory and practice of sustainability is substantial. Educational institutions must be the leaders in this subject to mold future generations’ incoming leaders into sustainability conscious critical thinkers. Current environmental issues such as climate change, CO2 Emissions, poverty and so on must impact these educational institutions to make sustainability education a priority in its curriculum. Addressing this problem requires a holistic approach which integrates sustainability education earlier on to grasp further understanding of sustainability actions in higher education and in society. Sustainability education exists in all levels. Although, sustainability education is much more prominent in higher education institutions as opposed to Elementary, Middle, and High Schools. Consequently, less students are prepared with the desired sustainability knowledge needed in higher education and students' future careers to instill in their disciplines since behavior is achieved through repetitive actions that were not set as a foundation earlier in their education. Approach: There were two approaches in this research. The first research approach was conducting a survey in 120 students, half of them in secondary education and the other half in higher education. The survey was formatted to analyze three different questions: 1) whether students in high school and higher education knew about sustainability 2) whether students' lifestyle consisted of pro-environmental actions, 3) and whether they learned to perform these actions in secondary education or higher education. The second approach was to create an educational tool to implement sustainability behavioral change strategies in their everyday lifestyles. Findings: Study found that most students are aware about sustainability. However, most students engage in pro-environmental actions in higher education because they started learning about them in higher education. Therefore, although most secondary education students are aware about sustainability, they aren't engaging in pro-environmental actions. In conclusion, a sustainability toolkit was created based on behavioral change strategies to reduce water usage, CO2 emissions, energy consumption, and waste output in their school and everyday lifestyles. Value: The efforts of sustainability in Higher Education have been clear in most recent years, although, there is still much resistance to change, transform and reimagine society and education for sustainability. The future of life and social world on Earth is in jeopardy since poverty, climate change, and lack of peace is occurring worldwide. Sustainability education must respond and act on this challenge subsequently to respect all forms of life and future generations. The mission of the sustainability toolkit is to create a pedagogy to assist educational institutions and communities to develop the skills and knowledge to work sustainably.

The electricity market in the South African economy uses specialised instruments in forecast-ing the energy load to be delivered. The current status quo operates with several forecasters from different offices, departments or businesses predicting for different purposes. This be-comes a challenge to derive a consolidated forecast. This study has attempted to develop a consolidating instrument that will merge all the forecasts from different offices, departments or businesses into one so-called ‘official forecast’. Such an instrument should be able to predict with accuracy the anticipated usage or demand. Article [18] examined patterns across G7 countries and forecasters to establish whether the present bias reflects the inefficient use of information, or whether it reflects a rational re- sponse to financial, reputation and other incentives operating for forecasters. This bias is particularly true for any electricity utility as forecasting is undertaken by different divisions; therefore each division has its own incentives. For instance, the generation division will tend to overstate their forecasts so as that there is no possibility of a shortage, whereas distri- bution (sales) might understate so as to give the impression of being profitable when more units are sold to consumers. Thus, the study attempts to rectify this bias by employing statistical tools in consolidating these forecasts. The results presented in this paper propose a newly developed procedure of consolidating energy demand forecasts from different users and accounting for different time horizons. Predicting for the short-term and long-term involves different measuring tools, which is one aspect of prediction this paper tackles.

I present a time synchronization algorithm for wireless sensor networks that aims to conserve sensor battery power. The proposed method creates a hierarchical tree by flooding the sensor network from a designated source point. It then uses a hybrid algorithm derived from the timing-sync protocol for sensor networks (TSPN) and the reference broadcast synchronization method (RBS) to periodically synchronize sensor clocks by minimizing energy consumption. In multi-hop ad-hoc networks, a depleted sensor will drop information from all other sensors that route data through it, decreasing the physical area being monitored by the network. The proposed method uses several techniques and thresholds to maintain network connectivity. A new root sensor is chosen when the current one's battery power decreases to a designated value. I implement this new synchronization technique using Matlab and show that it can provide significant power savings over both TPSN and RBS.