• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 75
  • 39
  • 16
  • 6
  • 5
  • 5
  • 4
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 183
  • 183
  • 62
  • 56
  • 49
  • 38
  • 34
  • 26
  • 24
  • 23
  • 22
  • 22
  • 21
  • 18
  • 17
  • 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.
131

Bolivia, Brasil e a guerra do gas / Bolivia, Brazil and the war gas : the political implications from Energetic Integration in the Strategy and National Security

Hage, José Alexandre Altahyde 19 December 2006 (has links)
Orientador: Shiguenoli Miyamoto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciencias Humanas / Made available in DSpace on 2018-08-09T06:11:01Z (GMT). No. of bitstreams: 1 Hage_JoseAlexandreAltahyde_D.pdf: 7445204 bytes, checksum: 94812291a030bdbec745f8248603a6ab (MD5) Previous issue date: 2006 / Resumo: Meu trabalho de monografia procura visar as relações políticas e econômicas entre a Argentina e Brasil no âmbito do Mercosul, plano de integração regional conhecido pelo Tratado de Assunção em 1991. A hipótese da minha monografia é averiguar a possibilidade de emergir comportamentos entre a realidade por parte dos países que integram o Mercosul, principalmente, a Argentina e Brasil, os dois maiores sócios do Mercosul. Em outras palavras é analisar se de fato há comportamentos realistas por parte dos dois maiores países da região do cone Sul. Comportamento realista neste caso é visto no emprego de conceitos ligados á política clássica, como hegemonia, dependência, interesse nacional e história internacional. Estes são conceitos da ciência política amplamente realizados nas relações internacionais / Abstract: Not informed. / Doutorado / Doutor em Ciência Política
132

Technical and economical evaluation of combined cooling, heat and power technology: a brazilian study case considering different consumers

Givisiez, Arthur Gonçalves 29 August 2018 (has links)
Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-09-25T13:55:05Z No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-10-01T18:11:02Z (GMT) No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) / Made available in DSpace on 2018-10-01T18:11:02Z (GMT). No. of bitstreams: 1 arthurgoncalvesgivisiez.pdf: 15097769 bytes, checksum: e434481fde7014f783d8b75137429fba (MD5) Previous issue date: 2018-08-29 / O mundo está tentando mudar para um ambiente de energia mais limpa, especialmente no setor de geração de eletricidade, que é responsável por uma grande parcela das emissões de CO2. No Brasil, fontes renováveis são responsáveis por grande parte da geração de eletricidade, mas mudanças atuais no clima brasileiro trouxeram uma necessidade de diversificação na matriz energética. Logo, a geração distribuída é uma boa maneira de diversificar a matriz energética brasileira. Considerando que os sistemas de cogeração se enquadram na geração distribuída, e que os prédios brasileiros necessitam de resfriamento, devido ao clima quente, o uso de cogeração adicionado à um chiler de absorção ou absorção pode ser muito útil. O sistema de trigeração é um processo altamente eficiente, que pode produzir eletricidade, aquecimento e resfriamento a partir da mesma fonte de energia primária. No entanto, existem poucas pesquisas sobre os sistemas de trigeração no Brasil, especialmente em pequena e micro escala. Assim, esta dissertação fará uma avaliação técnica e econômica de sistemas de micro e trigeração para diferentes edifícios sob políticas tarifárias distintas no Brasil. Para tanto, este trabalho otimizará o dimensionamento e o cronograma de despacho mensal dos sistemas de trigeração para cada um dos quatro estudos de caso. Em seguida, avaliará o valor presente líquido máximo (VPL) considerando a variação da taxa de desconto e da taxa de conversão do dólar norte-americano. Na sequência, o índice de dependência da rede (GDI), o payback descontado, o custo nivelado da energia (LCOE) e a razão da energia primária (PER) para os melhores VPLs serão apresentados e analisados. Como resultado, esta dissertação mostrará que as plantas de trigeração podem ser lucrativas e certamente ser uma maneira eficiente de utilização de uma geração distribuída confiável e controlável. Além disso, provará que é possível encontrar situações em que a planta de trigeração possa oferecer uma alta taxa de energia primária (PER), um adequado custo de energia nivelado (LCOE) e, ao mesmo tempo, pode proporcionar economia financeira com tempo de retorno razoável em edifícios brasileiros. / The world is trying to move to a cleaner energy environment, especially on the electricity generation sector, which is responsible for a large share of CO2 emissions. In Brazil,crenewable energy sources are responsible for a great part of the electricity generation, but current changes in the Brazilian climate brought a necessity of diversification on the energy matrix. Then, distributed generation is a good way to diversify the Brazilian power matrix. Considering that cogeneration systems are distributed generation, and Brazilian buildings have need of cooling, due to the warm weather, the use of cogeneration equipped with an absorption or adsorption chiller could be beneficial. The trigeneration system is a highly efficient process, which can produce electricity, heating and cooling from the same primary energy source. However, there are really few researches concerning trigeneration systems in Brazil, especially on small and micro plants. Thus, this thesis will make and provide a technical and economical evaluation of small and micro trigeneration systems to different buildings under distinct tariff policies in Brazil. To do so, this work will optimize the sizing and monthly schedule the dispatch of the trigeneration systems to each one of the four study cases. Then, it will evaluate the maximum net present value (NPV) considering the variation of discount rate and US Dollar conversion rate. In the sequence, the grid dependence index (GDI), the discounted payback, the levelized cost of energy (LCOE) and the primary energy ratio (PER) to the best NPVs will be presented and analysed. As a result, this thesis will show that trigeneration plants can be profitable and can be certainly an efficient way to adopt a reliable and controllable distributed generation. Also, it will prove that it is possible to find situations in which the trigeneration plant can offer a high primary energy ratio, a fair levelized cost of energy, and in the meantime, it can provide financial savings with fair payback time in Brazilian buildings.
133

Integrated Community Energy Systems

Koirala, Binod Prasad January 2017 (has links)
Energy systems across the globe are going through a radical transformation as a result of technological and institutional changes, depletion of fossil fuel resources, and climate change. Accordingly, local energy initiatives are emerging and increasing number of the business models are focusing on the end-users. This requires the present centralized energy systems to be re-organized. In this context, Integrated community energy systems (ICESs) are emerging as a modern development to re-organize local energy systems allowing simultaneous integration of distributed energy resources (DERs) and engagement of local communities. With the emergence of ICESs new roles and responsibilities as well as interactions and dynamics are expected in the energy system. Although local energy initiatives such as ICESs are rapidly emerging due to community objectives, such as cost and emission reductions as well as resiliency, assessment and evaluation of the value that these systems can provide to both local communities and the whole energy system are still lacking. The value of ICESs is also impacted by the institutional settings internal and external to the system. With this background, this thesis aims to understand the ways in which ICESs can contribute to enhancing the energy transition. This thesis utilizes a conceptual framework consisting of institutional and societal levels in order to understand the interaction and dynamics of ICESs implementation.  Current energy trends and the associated technological, socio-economic, environmental and institutional issues are reviewed. The developed ICES model performs optimal planning and operation of ICESs and assesses their performance based on economic and environmental metrics. For the considered community size and local conditions, grid-connected ICESs are already beneficial to the alternative of solely being supplied from the grid, both in terms of total energy costs and CO2 emissions, whereas grid-defected systems, although performing very well in terms of CO2 emissions reduction, are still rather expensive. ICESs ensure self-provision of energy and can provide essential system services to the larger energy system. This thesis has demonstrated the added value of ICESs to the individual households, local communities and the society. A comprehensive institutional design considering techno-economic and institutional perspectives is necessary to ensure effective contribution of ICESs in the energy transition. / Energisystem över hela världen går igenom en radikal omvandling till följd av tekniska och institutionella förändringar, utarmning av fossila bränsleresurser och klimatförändringar. Följaktligen växer lokala energiinitiativ fram och ett ökande antal affärsmodeller fokuserar på slutanvändarna. Detta förutsätter att de nuvarande centraliserade energisystemen omorganiseras. I det här sammanhanget utvecklas integrerade samhällsenergisystem (ICES) som en modern utveckling för att omorganisera lokala energisystem som möjliggör samtidig integration av distribuerade energiresurser och engagemang från lokala samhällen. Med framväxten av ICES nya roller och ansvarsområden samt interaktioner och dynamik förväntas i energisystemet. Även om lokala energiinitiativ som ICES snabbt framträder på grund av samhällsmål, såsom kostnad och utsläppsminskningar samt resiliens, bedömning och utvärdering av det värde som dessa system kan ge till både lokala samhällen och hela energisystemet saknas fortfarande. Värdet av ICES-värden påverkas också av de institutionella inställningarna internt och externt för systemet. Med denna bakgrund syftar denna avhandling till att förstå hur ICES kan bidra till att förbättra energiövergången. Denna avhandling använder en konceptuell ram som består av institutionella och samhälleliga nivåer för att förstå samspelet och dynamiken i ICES-genomförandet. Nuvarande energitrender och de därtill hörande tekniska, socioekonomiska, miljömässiga och institutionella frågorna ses över. Den utvecklade ICES-modellen utför optimal planering och drift av ICES och bedömer deras prestanda baserat på ekonomiska och miljömässiga mätvärden. För den ansedda samhällsstorleken och lokala förhållandena är nätanslutna ICES redan fördelaktiga jämfört med alternativet att endast försörjas från nätet, både när det gäller totala energikostnader och koldioxidutsläpp, medan nät-defekterade system, även om de fungerar väldigt bra i termer av minskningen av koldioxidutsläppen fortfarande är ganska dyra. ICES garanterar självförsörjning av energi och kan tillhandahålla viktiga systemtjänster till det större energisystemet. Denna avhandling har visat mervärdet av ICES till de enskilda hushållen, lokalsamhällena och samhället. En omfattande institutionell utformning med hänsyn till de tekno-ekonomiska och institutionella perspektiven är nödvändigt för att säkerställa ett effektivt bidrag från ICES i energiövergången. / Los sistemas energéticos en todo el mundo atraviesan una transformación radical como resultado de cambios tecnológicos e institucionales, el agotamiento de combustibles fósiles y el cambio climático. Por consiguiente, las iniciativas locales de energía están surgiendo y los modelos de negocio se centran cada vez más en los usuarios finales. Esto requiere la reorganización de los actuales sistemas energéticos centralizados. En este contexto, los sistemas integrados de energía comunitaria (ICES, por sus siglas en inglés) están emergiendo como un desarrollo moderno para reorganizar los sistemas energéticos locales, permitiendo la integración simultánea de los recursos energéticos distribuidos y la participación de las comunidades locales. Con la aparición de ICESs se esperan nuevos roles y responsabilidades, así como interacciones y dinámicas, en el sistema energético. Aunque las iniciativas locales en materia de energía, como las ICESs, están surgiendo rápidamente debido a los objetivos de la comunidad, tales como la reducción de costos y emisiones, así como la resiliencia, y la evaluación, siguen careciendo del valor que estos sistemas pueden brindar tanto a las comunidades locales como a todo el sistema energético. El valor de los ICESs también se ve afectado por los entornos institucionales tanto internos como externos al sistema. Con este trasfondo, esta tesis pretende comprender las formas en que los ICESs pueden contribuir a mejorar la transición energética. Esta tesis utiliza un marco conceptual que consiste en niveles institucionales y sociales para comprender la interacción y dinámica de la implementación de los ICESs.  Además, esta tesis revisa las tendencias actuales de energía y los problemas tecnológicos, socioeconómicos, ambientales e institucionales asociados. La tesis desarrolla un modelo que optimiza la planificación y el funcionamiento óptimos de ICESs y evalúa su funcionamiento basado en métricas económicas y ambientales. Para el tamaño de la comunidad y las condiciones locales consideradas, los ICESs conectados a la red ya son beneficiosos tanto en términos de costos totales de energía como de emisiones de CO2 comparado con la alternativa de ser suministrados únicamente desde la red, mientras que los sistemas aislados y desconectados de la red, aunque desempeñándose muy bien en términos de reducción emisiones de CO2, siguen siendo bastante más costosos. Los ICESs garantizan el autoabastecimiento de energía y pueden proporcionar servicios esenciales al resto del sistema energético. Esta tesis demuestra el valor añadido de los ICESs a los hogares individuales, las comunidades locales y la sociedad. Un diseño integral que considere las perspectivas tecno-económicas e institucionales es necesario para asegurar la contribución efectiva de los ICESs en la transición energética. / Energiesystemen over de hele wereld gaan door een radicale transformatie als gevolg van technologische en institutionele veranderingen, uitputting van fossiele brandstoffen en klimaatverandering. Bijgevolg komen lokale energie-initiatieven op en richten steeds meer verdienmodellen zich op de eindgebruikers. Dit vereist dat de huidige gecentraliseerde energiesystemen opnieuw worden georganiseerd. In deze context komen geïntegreerde energiegemeenschapssystemen (ICESs) op als een moderne ontwikkeling om lokale energiesystemen te reorganiseren, welke gelijktijdige integratie van lokale energiebronnen en betrokkenheid van lokale gemeenschappen mogelijk maakt. Het wordt verwacht dat de opkomst van ICESs zowel nieuwe rollen en verantwoordelijkheden met zich meebrengt. Hoewel lokale energie-initiatieven zoals ICESs snel opkomen door de  doelstellingen van de gemeenschap, zoals kosten- en emissiereducties en veerkracht, schort het nog steeds aan beoordeling en evaluatie van de waarde die deze systemen kunnen hebben voor zowel de lokale gemeenschappen als het hele energiesysteem. De waarde van ICESs wordt ook beïnvloed door de institutionele kenmerken binnen en buiten het systeem. Met deze achtergrond beoogt dit proefschrift te begrijpen op welke manieren de ICESs kunnen bijdragen aan de verbetering van de energietransitie. Dit proefschrift maakt gebruik van een conceptueel raamwerk bestaande uit institutionele en maatschappelijke niveaus om de interactie en dynamiek van de implementatie van de ICES te begrijpen. De huidige energietrends en de bijbehorende technologische, sociaal-economische, milieu- en institutionele problemen worden beoordeeld. Het ontwikkelde ICES-model voert optimale planning en gebruik van ICESs uit en beoordeelt hun prestaties op basis van economische en milieu-indicatoren. Voor de beschouwde gemeenschapsgrootte en lokale omstandigheden zijn  op het net aangesloten ICESs al voordelig ten opzichte van het alternatief waarbij uitsluitend vanuit het net wordt geleverd, zowel wat betreft de totale energiekosten als de CO2-uitstoot, terwijl de grid-defected systemen, hoewel heel goed presterend in termen van CO2-emissiereductie, nog steeds vrij duur zijn. ICESs zorgen voor zelfvoorziening van energie en kunnen essentiële systeemdiensten leveren aan het grotere energiesysteem. Dit proefschrift heeft de toegevoegde waarde van ICESs voor de individuele huishoudens, lokale gemeenschappen en de samenleving aangetoond. Een uitgebreid institutioneel ontwerp met inachtneming van techno-economische en institutionele perspectieven is nodig om de effectieve bijdrage van de ICESs in de energietransitie te waarborgen. / <p>QC 20170911</p> / Sustainable Energy Technologies and Strategies
134

Energy Management in Smart Cities

Calvillo Munoz, Christian Francisco January 2017 (has links)
Models and simulators have been widely used in urban contexts for many decades. The drawback of most current models is that they are normally designed for specific objectives, so the elements considered are limited and they do not take into account the potential synergies between related systems. The necessity of a framework to model complex smart city systems with a comprehensive smart city model has been remarked by many authors. Therefore, this PhD thesis presents: i) a general conceptual framework for the modelling of energy related activities in smart cities, based on determining the spheres of influence and intervention areas within the city, and on identifying agents and potential synergies among systems, and ii) the development of a holistic energy model of a smart city for the assessment of different courses of action, given its geo-location, regulatory and technical constraints, and current energy markets. This involves the creation of an optimization model that permits the optimal planning and operation of energy resources within the city. In addition, several analyses were carried out to explore different hypothesis for the smart city energy model, including: a)      an assessment of the importance of including network thermal constraints in the planning and operation of DER systems at a low voltage distribution level, b)      an analysis of aggregator’s market modelling approaches and the impact on prices due to DER aggregation levels, and c)      an analysis of synergies between different systems in a smart city context. Some of the main findings are: It is sensible to not consider network thermal constraints in the planning of DER systems. Results showed that the benefit decrement of considering network constraints was approximatively equivalent to the cost of reinforcing the network when necessary after planning without considering network constraints. The level of aggregation affects the planning and overall benefits of DER systems. Also, price-maker approaches could be more appropriate for the planning and operation of energy resources for medium to large aggregation sizes, but could be unnecessary for small sizes, with low expected impact on the market price. Synergies between different energy systems exist in an interconnected smart city context. Results showed that the overall benefits of a joint management of systems were greater than those of the independently managed systems. Lastly, the smart city energy model was applied to a case study simulating a real smart city implementation, considering five real districts in the southern area of Madrid, Spain. This analysis allowed to assess the potential benefits of the implementation of a real smart city programme, and showed how the proposed smart city energy model could be used for the planning of pilot projects. To the best of our knowledge, such a smart city energy model and modelling framework had not been developed and applied yet, and no economic results in terms of the potential benefits of such a smart city initiative had been previously reported. / <p>QC 20171010</p>
135

Incorporating human behaviour in an agent based model of technology adoption in the transition to a smart grid

Snape, Joseph Richard January 2015 (has links)
The requirement for affordable, secure and sustainable energy production is a pressing global challenge and the production of electricity with low carbon emissions is crucial. This usually entails large quantities of renewable energy generation, which is intermittent and often highly distributed throughout the electricity supply system. One of the proposed schemes to manage such generation is the smart grid, the transition to which forms the context for this research. The aim is to investigate the effect of certain psychological and social influences on the adoption of technology necessary to enable smart grids, in order to understand the implications for effective energy policy. In particular, the case of photovoltaic (PV) system adoption in the UK is studied. Empirical data detailing PV installations registered for the Feed in Tariff is analysed in order to understand rates of adoption and how they vary across both time and space. This analysis is combined with a review of policy intervention and literature from psychology to understand drivers for adoption among householders. The results from this study are then used to inform the design of an Agent Based Model of technology adoption within the smart grid context. The decision making of householders is modelled using an algorithm based on Social Cognitive Theory. The model is used to simulate different conditions and generate adoption scenarios in order to understand the potential effects of different parameters on adoption rates. In order to combine the analysis resulting from these methods, the multi-level perspective on transition in socio-technical systems is used to understand how a transition to a smart grid could be described and how adoption of PV in the UK under the Feed in Tariff incentive fits into such a transition. The results show that whilst economic incentive policies have had success in some areas adoption is also dependent on many non-financial parameters. Simulations show that the observability of adoption and the perceived inconvenience or urgency of adoption can have dramatic effects on rates of adoption, in some cases outweighing the rational economic effects of financial incentives. The implication for smart grid related policy is that non-financial factors should be taken into account as well as the more typical financial considerations in efforts to encourage adoption of necessary enabling technology by householders. The models developed could be used in further work to examine in detail adoption of other technologies such as smart home energy management systems and the interaction between adoption rates of multiple smart technologies.
136

ANALÝZA VLIVU DOTACÍ OBNOVITELNÝCH ZDROJŮ ENERGIE NA EFEKTIVNOST KONKRÉTNÍCH VYBRANÝCH PROJEKTŮ / ANALYSIS OF SUBSIDIES FOR RENEWABLE ENERGY ON EFFECTIVENESS OF SPECIFIC PROJECTS

Šouláková, Marie January 2009 (has links)
Graduation theses deal with grants on renewable energy sources. Equate to possibilities supports renewable energy sources and smoothing - out whether be necessary further promotion above law 180/2005 Sb. Lockwork work smoothing - out this question for instance 3 kinds renewable energy sources, behind using two economic criteria namely net present value and internal rate of return.
137

Analýza investic do energetických zdrojů / Analysis of investment in energy resources

Petríková, Tereza January 2009 (has links)
Diploma thesis deals with analysis of energy resources. The aim is to map the potential of renewable resources in the Czech Republic and through multicriteria decision making to assess the potential investment options in renewable energy in the Czech Republic.
138

Projektové financování investičních projektů se zaměřením na projekty z oblasti obnovitelných zdrojů energie / Project Financing of Investment Projects in the field of Renewable Energy Resources

Karnetová, Lucie January 2008 (has links)
My thesis is focused on Project Financing of Investment Projects in the field of Renewable Energy Resources. The theoretical section, see Chapter Two, characterises the nature of project financing, parties, principles for successful project financing, types of capital invested in projects and their resources, risks, guarantees and securities. The practical (third) part of the thesis is oriented to specifics of project financing of Renewable Energy Resources. First of all principles for the assessment both of project bearers and projects in terms of quality are specified. Furthermore, principals for the assessment of financial terms of projects are given. The fourth and concurrently the final Chapter analyses a particular project in the field of renewable energy resources mostly from the financial point of view.
139

Podnikatelský plán - Fotovoltaická elektrárna v Rumunsku / Photovoltaic power plant in Romania

Brothánek, Ondřej January 2012 (has links)
Renewable energy resources, especially photovoltaics, have experienced enormous boom all over the world in the past few years. It was completely the same in Czech Republic where you would not find anybody without his own opinion regarding PV business. Installation of PV power plants has become very attractive business, with very significant role in 2011 in Czech Republic. At this time, this solar boom has found its "home" in other European countries, particularly in Eastern Europe. The post of the new Eastern Europe's "powerhouse" can defend even Romania, that's the cause I have chosen this country as the subject of this thesis. The aim of this thesis is to create a business plan for PV power plant and evaluate the investment opportunity of its installation in Romania. And then by means of a sensitivity analysis find out the impact of external factors that can significantly affect the profitability of the project.
140

Tagungsband Umwelt, Energie und Rohstoffe 2021 & 21. Geokinematischer Tag: 05.-07. Mai 2021, Freiberg

Benndorf, Jörg 15 September 2021 (has links)
Das Institut für Markscheidewesen und Geodäsie veranstaltete vom 05. bis 07. Mai 2021, in Freiberg, die gemeinsame Tagung Umwelt, Energie Rohstoffe & 21. Geokinematischer Tag 2021, um die neuesten Entwicklungen im Markscheidewesen und den angrenzenden Fachgebieten vorzustellen und zu diskutieren.

Page generated in 0.0656 seconds