Made available in DSpace on 2014-10-09T12:27:00Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:56:30Z (GMT). No. of bitstreams: 0 / Neste trabalho foram selecionadas, estabelecidas e estimadas possíveis fontes de produção de hidrogênio para a geração de energia elétrica de forma distribuída, com a utilização de célula a combustível. Estudaram-se três fontes de geração de energia renovável no Brasil: a biomassa, a energia solar fotovoltaica e a energia eólica. Para o estabelecimento dos valores numéricos foram avaliadas as principais culturas agrícolas de cada estado pertencente à respectiva região e a quantidade de biomassa, na forma de rejeito agrícola, capaz de ser gerada para futura utilização na produção de hidrogênio. Da mesma maneira foi investigada e avaliada numericamente a capacidade de produção de hidrogênio através das energias eólica e solar fotovoltaica para cada região do Brasil, tomando-se como base o processo de eletrólise. Mediante os resultados obtidos é possível demonstrar as potencialidades do Brasil para a geração de energia elétrica de maneira distribuída e com a substituição de combustíveis fósseis e por conseqüência, com a melhoria do meio ambiente. / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:42:29Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:59:56Z (GMT). No. of bitstreams: 0 / A atual problemática ambiental provocada pela atividade humana tem ganhado destaque na sociedade, à medida que se busca o desenvolvimento mundial. Um fator de extrema relevância neste cenário é a produção de energia elétrica, responsável por uma grande parcela das emissões causadoras do efeito estufa. Por conta disso, é preciso pensar em um desenvolvimento sustentável, com fontes alternativas de energia atrativas para esse objetivo, principalmente em localidades não abastecidas pela rede convencional de eletricidade, como é o caso de muitas comunidades da região nordeste brasileira. Assim, esse trabalho tem por objetivos calcular o custo ambiental, na fase de geração de eletricidade, para as fontes alternativas de energia solar, eólica e biomassa e estimar a viabilidade econômica dessas fontes em pequenas comunidades da região Nordeste do Brasil, considerando os custos evitados. É preciso identificar as externalidades e valorá-las de forma adequada para que os custos ou benefícios possam ser internalizados e reflitam de forma correta a viabilidade ou inviabilidade econômica dessas fontes. Para os objetivos propostos, adotou-se o método dos custos evitados para o cálculo das externalidades. Essa variável foi incluída no equacionamento desenvolvido para todas as fontes de energia alternativas consideradas. Foram feitos os cálculos de viabilidade econômica, considerando as novas configurações adotadas, sendo que o novo equacionamento foi reprogramado no Programa de Cálculo de Custos de Energias Alternativas, Solar, Eólica e Biomassa (PEASEB). Os resultados demonstraram que a fonte mais viável e amplamente aplicável em pequenas comunidades da região nordeste brasileira é a energia solar fotovoltaica em sistemas isolados. / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Na presente tese, propÃe-se um controlador robusto LQG/LTR (Linear Quadratic Gaussian with Loop Transfer Recovery) com aÃÃo integral (LQG/LTRI) em uma nova aplicaÃÃo para o ajuste dos controladores do conversor do lado da mÃquina e do conversor do lado rede elÃtrica em um sistema de conversÃo eÃlica utilizando um gerador de induÃÃo duplamente alimentado (Doubly-Fed Induction Generator - DFIG). A metodologia de controle proposta assegura a robustez em relaÃÃo à rejeiÃÃo do erro de rastreamento, insensibilidade a variaÃÃes paramÃtricas, alÃm de permitir que erros de medida e modelagem sejam incorporados no projeto. Testes de robustez e desempenho foram realizados para variaÃÃes dos parÃmetros internos da mÃquina e variaÃÃes de referÃncia de velocidade. Resultados de simulaÃÃo e experimentais, obtidos em um protÃtipo de laboratÃrio com uma mÃquina de 2kW sÃo apresentados para validar e demonstrar o bom desempenho e robustez do controlador proposto comparado com os controladores clÃssicos Proporcional-Integral (PI) em um sistema de geraÃÃo eÃlica com mÃquinas DFIG. / It is proposed in this thesis a LQG/LTR robust controller (Linear Quadratic Gaussian with Loop Transfer Recovery) with integral action (LQG/LTRI) in a new application for gain tuning for the rotor side converter and grid side converter in a wind energy conversion system (WECS) with Doubly-Fed Induction Generator(DFIG). The proposed control method assures the robustness with respect to the tracking error rejection, insensitivity to parameter variations and permits that measurement and modeling errors are incorporated in the project. Robustness and performance tests were performed for variations of machine internal parameters and speed. Simulation and experimental results, obtained from a laboratory prototype that uses a 2 kW machine are presented to validate and demonstrate the robustness and performance of the proposed controller through the comparison with the proportional and integral (PI) controller employed in a wind energy conversion system with DFIG.

Submitted by Edineia Teixeira (edineia.teixeira@unioeste.br) on 2018-03-07T19:42:45Z No. of bitstreams: 2 Thalyta_Basso2017.pdf: 3796237 bytes, checksum: d1ec6e9511427a7af0fbfdd055261c28 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-03-07T19:42:45Z (GMT). No. of bitstreams: 2 Thalyta_Basso2017.pdf: 3796237 bytes, checksum: d1ec6e9511427a7af0fbfdd055261c28 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-02-17 / One of the biggest concerns in the contemporary world is the overuse of electricity. Along with that, in the last few years, the growth of investment in the sector of wind and solar power generation has stood out, which has contributed to supply for the needs faced by Brazil due to unfavorable hydrological conditions, which impair the production in the water power plants. Thus, a study was done on the technical and economic feasibility of the implantation of a small wind powerhouse in a grain warehouse, located in São João do Oeste, district of Cascavel-PR, to supply the power needs of such a building. Based on data provided by SIMEPAR, for every 10 meters of height, the annual/daily average of wind speed in the area was 4,12 m/s, the average temperature was 20,4 ºC and the average air pressure was 937,81 hPa, considering the last 5 years of measuring. Through the technical analysis and the cost survey, the decision was taken to use 3 turbines of 80 kW of power, at 30 meters of height, which would supply about 80% of the power needs in the place, generating credit in the months of low consume to be used in the months of higher use. However, the budget also proved to be unfeasible by the Net Present Value Method, the Internal Rate of Return and the Deducted Pay-Back as well, determining that at the end of the useful life of the turbines, the investment wouldn’t have been paid and it would be necessary to change the equipment, creating a debt over debt for the investor. Comparing the cost of such an investment in Brazil to other countries, a variation of 529% was observed, and the Brazilian cost for the system adopted is R$25.625,00/kW, while the foreign average is R$4.843,34/kW; Such a difference could be related to importation rate, taxes, reduced popularization and the competition between suppliers in Brazil / Uma das questões mais preocupantes no mundo contemporâneo é o uso demasiado de energia elétrica. Aliado a isso, nos últimos anos, tem se destacado o crescimento de investimentos nos setores de geração solar e eólica, que tem contribuído para suprir as dificuldades enfrentadas pelo Brasil com as condições hidrológicas desfavoráveis, que prejudicam a produção pelas hidrelétricas. Assim, realizou-se um estudo de viabilidade técnica e econômica da implantação de uma pequena central geradora eólica em uma unidade armazenadora e beneficiadora de grãos, situada em São João do Oeste, distrito de Cascavel-PR, para suprir as necessidades energéticas dessa edificação. Com base nos dados obtidos com o SIMEPAR, para 10 metros de altura, a média anual diária da velocidade do vento no local foi de 4,12 m/s, a temperatura média de 20,4 ºC e a pressão atmosférica média de 937,81 hPa, considerando-se os últimos 5 anos de medições. Por meio de análise técnica e do levantamento de custos, optou-se por utilizar 3 turbinas de 80 kW de potência, a 30 metros de altura, que supririam cerca de 80% das necessidades energéticas da unidade, gerando créditos nos meses de baixo consumo para serem compensados nos meses de maior utilização energética. Porém, o orçamento mostrou-se inviável pelo Método do Valor Presente Líquido, da Taxa Interna de Retorno e também do Pay-Back Descontado, determinando que ao final da vida útil das turbinas, o investimento ainda não teria sido pago e haveria necessidade de troca dos equipamentos, gerando dívida sobre dívida para o investidor. Comparando-se o custo do referido investimento no Brasil com valores de outros países, observou-se uma variação de 529%, sendo que o custo brasileiro para o sistema adotado resulta em R$25.625,00/kW, enquanto a média estrangeira é de R$4.843,34/kW, podendo essa diferença ter relação com a taxa de importação, impostos e reduzida popularização e concorrência entre empresas fornecedoras no Brasil

De svenska fjällen skyddas i dagsläget av miljömålet Storslagen fjällmiljö, ett mål som ämnar bevara fjällens ursprunglighet och därmed skydda dem mot ingrepp. Den svenska regeringen har även inrättat 13 områden klassade som obruten fjällmiljö, områden vars natur- och kulturvärden ska värnas om och som, i så stor utsträckning som möjligt, ska hållas orörda. Båda dessa skyddsformer hotas nu av de planer som finns på att bygga ut vindkraften i landet. I denna studie undersöks den visuella påverkan som finns från dagens vindkraftverk samt den ökade visuella påverkan som genom fattade beslut är på väg. Metoden för studien är en rumslig GIS-analys som undersöker hur stora områden som vindkraften påverkar visuellt. Detta kopplas sedan till studier kring platskänsla, platsidentitet och vindkraftens konflikt med landskapet. Studien har visat att vindkraftverken i de svenska fjällen har en signifikant visuell påverkan på de obrutna fjällen och att miljömålet Storslagen fjällmiljö i dagsläget inte ser ut att uppnås. Dock måste nämnas att hur den framtida förändringen av landskapsbilden i de svenska fjällen kommer att uppfattas till stor grad beror på varje individs koppling till landskapet som förändras. / In the Swedish mountains the government has established 13 areas, covering around 10 % of the country, as areas of undisturbed mountain regions. These areas are to be protected against activities threatening environmental and cultural values. There is also an environmental goal aiming to maintain the originality of the Swedish mountains called Storslagen fjällmiljö, in translation: A magnificent mountain landscape. These two factors are being threatened by the future plans of increasing the number of wind turbines in these areas. In this study the visual effects of the existing and not yet existing wind turbines are being examined by performing a GIS-analysis. This is analyzed based on place sensitivity and people’s relation to their surrounding landscape. The study has shown that wind turbines have a significant visual impact on the undisturbed mountain regions and that the environmental goal aiming to keep the originality of the mountains does not reach its target. However, it must be pointed out that this future change in the scenic landscape of the Swedish mountains also can be seen as something good, this depending strongly on your relationship with the landscape.

This study examines different meanings attached to and practices adopted during Swedish local consultation processes on offshore wind power projects. It analyses the role played by those processes in a democratic planning context, as well as the ways in which they are implemented. It also identifies overarching process models. The study is informed by theories on democracy, planning, participation, communication, and media. The empirical material comprises three case studies, each examining experiences of local consultation processes for wind power projects that led to differences in local reception. Methodologically, the study triangulates analyses of semi-structured interviews, documents and news articles. The results show that, in a Swedish context, the role of local consultation processes is to create legitimacy and trust in the process and planning decisions. The complex dynamics become evident in the different forms of participation, knowledge generation, and communication employed during the consultation. This is shown to be the result of various democratic and planning attitudes to locally-situated interests and knowledge, which in turn lead to differing views on local understanding for and acceptance of project proposals. The study develops three schematic models that correspond to different types of consultation processes. An important conclusion is that the content and form of local consultation processes depends on the agency of several actors on different scales. They are not simple pre-designed by project planners, but the result of a far more complex interaction between a host of local actors, including officials, local media, and local communities. The categorisation of different local consultation processes could contribute to awareness about the implications of various ways of working with large-scale projects from local perspectives. / I den här avhandlingen undersöks lokala förankringsprocesser med ett särskilt fokus på havsbaserade vindkraftsprojekt. Diskussionen uppehåller sig vid frågor om förankringsprocessens roll i en svensk planeringskontext, samt hur olika utformningar av processen kan påverka det lokala mottagandet. Studien visar att förankringsprocesser ytterst handlar om legitimitet och tillit. I praktiken förekommer en stor variation, komplexitet och dynamik i lokala förankringsprocesser. Det yttrar sig bland annat genom olika former av deltagande, kunskapsbyggande och kommunikation. Centralt i resonemangen är demokratiska och planeringsmässiga förhållningssätt till platsbundna intressen och kunskaper. På så sätt tydliggörs skillnader i synen på förståelse och lokal acceptans avseende ett projektförslag. Genom studien urskiljs också tre schematiska förankringsmodeller som belyser sådana skillnader. Förståelse för lokala förankringsprocesser har betydelse inte minst avseende påverkan på lokal acceptans för storskaliga projekt.

There is consensus that Eskom, South Africa’s main energy supplier, needs to expand its energy generating capacity in order to satisfy the growing demand for electricity, but there is less agreement on how it should do this. The existing supply is heavily reliant on thermal generation using coal, but the combustion of fossil fuels for electricity generation may contribute to climate change because it causes harmful greenhouse gases to be emitted into the atmosphere. This emission is something South Africa has committed itself to reducing. One way of achieving this is by the adoption of cleaner technologies for energy generation. One of these technologies is harnessing wind energy. The problem with harnessing wind energy is where to locate the turbines to harness the wind because these turbines ‘industrialise’ the environment in which they are located. They are a source of increased noise, a visual disturbance, cause increased instances of bird and bat mortality and the destruction of flora or the naturalness of the landscape in the areas in which they are located. The residents located near wind farm developments are most negatively affected and bear the greatest cost in this regard. A proper social appraisal of wind turbine projects would have to take this cost into account. Before such developments are approved there should be an assessment made of the impact on the residents, these impacts should be incorporated into the cost-benefit analysis. The negatively affected residents should also be compensated. The objective of this study was not to undertake a cost-benefit analysis of such a wind farm proposal, but to estimate the negative external cost imposed on nearby residents of such an industry, and thereby calculate appropriate compensation to be paid to these residents. Quantifying preferences for proposed, but not-yet developed, wind farms may be done by applying non-market valuation techniques, e.g. through one of the stated preference methodologies, such as a discrete choice experiment. The selected study site for providing guidance was one where Red Cap Investments Pty (Ltd) has proposed the development of a wind farm - in the Kouga local municipality. The basis for drawing conclusions was the analysis of the response samples of two groups of Kouga residents, distinguished by socio economic status; 270 from each group, 540 in total. The methodology applied to analyse the responses was a discrete choice experiment. The questionnaire administered included attitude, knowledge and demographic questions as well as a choice experiment section. The choice experiment section of the questionnaire required that the respondents choose between two different hypothetical onshore wind energy development scenarios and a status quo option. The hypothetical scenarios comprised different levels of wind farm attributes. The attributes included in the experiment were determined by international studies and focus group meetings. These attributes were: distance between the wind turbines and residential area, clustering of the turbines (job opportunities created by the wind farm development for underprivileged respondent group), number of turbines and subsidy allocated to each household. Three different choice experiment models were estimated for each socio-economic group: a conditional logit (CL), nested logit (NL) and a random parameters logit (RPL) model. It was found that, in the affluent respondent group, the simpler CL model provided the best fit. In the underprivileged respondent group, the RPL model, with the number of jobs created by the wind farm project as a random parameter1, explained by the gender of the respondent, provided the best fit. The estimated models identified distance as an important factor in both sampled respondent groups. Both respondent groups preferred that the wind farm be located further away from their residential areas. In addition to distance, the underprivileged respondent group also valued new job opportunities as an important determinant of choice. The affluent respondent group were very sensitive to densely clustered turbines but were almost indifferent between two of the effects coded levels of the clustering attribute “moderately close together” and “widely spaced apart”. Welfare estimates for the significant attributes in each socio-economic group were computed from the best fit models. Table 1 shows the resulting willingness to accept (WTA) compensation measures for distance in both socio-economic respondent groups.

The purpose of this study was to investigate and suggest technologies that need to be considered by the Buffalo City Metropolitan Municipality management in order to alleviate electricity power shortages. It is very important to address the problems of electricity power shortages in the Buffalo City Metropolitan Municipality since it affects the households, offices and factories and it creates a negative image about the economic viability and investment opportunities in South Africa. Since ESKOM supplies electricity to the Buffalo City Metropolitan Municipality, they both require solutions that can sustain electricity availability for the current and future consumption by the households and the South African economy. It is of importance to report that the main causes of power shortages are the energy, capacity and the reserve margin constraints in the Buffalo City Metropolitan Municipality. The methodology used for this research was a mixed methods type of research. The literature review led to the formulation of research questionnaires that were subsequently used as the main tools for sourcing data in order to conduct an empirical study for this research. The empirical study was used to combine the quantitative and the qualitative research methodology in one research. The respondents to the structured and self-administered questionnaires comprised Beacon Bay and Mdantsane households that owned Solar Water Heaters. The other respondents that were interviewed with the aid of semi-structured questionnaires comprised ESKOM and the Buffalo City Metropolitan Municipality management teams. The responses from all the respondents were collected, arranged and presented in tables and graphs for the purpose of analysing and thereafter to report the outcomes. The outcomes were compared to the literature reviewed to test whether there is congruence between the two. This was done for the purpose of answering the following research question: Can alternative energy in the form of solar be a solution in improving power shortage in the Buffalo City Metro? Renewable energy was among the suggested solutions that were tested in other countries and found to be reliable. Renewable energy is divided into Solar Power Technology, Wind Power Technology, Small Hydro generation power, Biomass and other technologies. The Solar Power Technology is divided into three forms of energy. The first technology was Solar Photovoltaic Power, Concentrating Solar Power and the Solar Water Heating. The focus of this study was to investigate whether the use of Solar Power Technology in the form of Solar Water Heating can alleviate electricity power shortages in the Buffalo City Metropolitan Municipality. The other renewable energy technologies are reported as the limitations in this research that created opportunities for further research. The literature and empirical studies confirmed that the use of Solar Water Heaters alleviate power shortages in the Buffalo City Metropolitan Municipality since most of the respondents agreed that when Solar Water Heaters are installed and used in the households, electricity power is saved. The respondents further agreed that since Solar Water Heaters use the sun to heat water they do not use electric geysers anymore. They further agreed that a decrease in electricity expenses per household, per day, per month and per annum has been achieved due to the use of Solar Water Heaters. The Solar Water Heaters were reported by most respondents as confirmed in the literature that they are reliable since they do not trip when there is a planned or an emergency power outages in the Buffalo City Metropolitan Municipality area because they are powered by the sunlight. They are safe and have a longer economic life. They can be used in areas that do not have existing power supply. The key findings were that, both quantitative and qualitative results yielded results that were congruent with the literature reviewed. The congruence was reported in terms of electricity power saving, reduction in electricity expenses, per household, its reliability, the longer economic life and the safety of Solar Water Heaters. The installation of Solar Water Heaters has proven to be a good decision since they alleviated power shortages in the households that are in the rural areas, townships and in the upmarket residential places. It was recommended to the Buffalo City Metropolitan Municipality and ESKOM management to install more Solar Water Heaters and to increase the subsidies for the buyers of Solar Water Heaters especially the Buffalo City Metropolitan Municipality; to increase the marketing of Solar Water Heaters and to further educate electricity users about the Demand Side Management. This approach will encourage electricity users to reduce their demand for electricity in order to reap the benefits of power savings and sustainability of electricity supply for the potential increase of the economy in Eastern Cape Province.

The work focuses on wind-power energetics area in the Czech republic. On the basis of a set referential project, which is typical for current Czech conditions, it intends to answer two key questions. The first one deals with risk and inquires into how critical individual factors are. For this purpose financial analysis and especially sensitivity analysis are used. The other issue solved in this work is detection of economic efficiency of the referential project. The output is based on the prediction of the critical factors.

This research has developed a novel sustainability assessment framework for electricity technologies and scenarios, taking into account techno-economic, environmental and social aspects. The methodology uses a life cycle approach and considers relevant sustainability impacts along the supply chain. The framework is generic and applicable to a range of electricity technologies and scenarios. To test the methodology, sustainability assessments have been carried out first for different technologies and then for a range of possible future electricity scenarios for the UK. The electricity options considered either contribute significantly to the current UK electricity mix or will play a greater role in the future; these are nuclear power (PWR), natural gas (CCGT), wind (offshore), solar (residential PV) and coal power (subcritical pulverised). The results show that no one technology is superior and that certain tradeoffs must be made. For example, nuclear and offshore wind power have the lowest life cycle environmental impacts, except for freshwater eco-toxicity for which gas is the best option; coal and gas are the cheapest options, but both have high global warming potential; PV has relatively low global warming potential but high cost, ozone layer and resource depletion. Nuclear, wind and PV increase certain aspects of energy security but introduce potential grid management problems; nuclear also poses complex risk and intergenerational questions. Five potential future electricity mixes have also been examined within three overarching scenarios, spanning 2020 to 2070, and compared to the present-day UK grid. The scenarios have been guided by three different approaches to climate change: one future in which little action is taken to reduce CO2 emissions (‘65%’), one in which electricity decarbonises by 80% by 2050 in line with the UK’s CO2 reduction target (‘80%’), and one in which electricity is virtually decarbonised (at the point of generation) by 2050, in line with current policy (‘100%’).In order to examine the sustainability implications of these scenarios, the assessment results from the present-day comparison were projected forward to describe each technology in future time periods. Additional data were compiled so that coal with carbon capture and storage (CCS) – a potentially key future technology – could be included. The results of the scenario analyses show that the cost of generating electricity is likely to increase and become more capital-intensive. However, the lower-carbon scenarios are also at least 87% less sensitive to fuel price volatility. Higher penetration of nuclear and renewables generally leads to better environmental performance and more employment, but creates unknown energy storage costs and, in the case of nuclear power and coal CCS, the production of long-lived waste places a burden of management and risk on future generations. Therefore, the choice of the ‘most sustainable’ electricity options now and in the future will depend crucially on the importance placed on different sustainability impacts; this should be acknowledged in future policy and decision making. A good compromise requires strategic government action; to provide guidance, specific recommendations are made for future government policy.