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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.
1

Análise integrada do sistema energético urbano: estudo de caso da cidade de Porto Alegre / Integrated analysis of the urban energy system: case study of the city of Porto Alegre

Weber, Natália de Assis Brasil 20 March 2017 (has links)
Nos dias atuais as cidades são o epicentro de uma transformação energética, pois, são elas as principais consumidoras de matéria e energia. Energia fornecida, em sua maioria, através de um sistema convencional, centralizado e ineficiente. Dessa forma, são nos centros urbanos que poderão ser melhor implementadas estratégicas de eficiência energética e conservação de energia. Contudo, antes que os municípios se comprometam com novas iniciativas políticas e investimentos, o primeiro passo é melhorar a compreensão do sistema energético local. Por conseguinte, o objetivo central desta pesquisa é compreender de forma mais integrada o sistema energético de uma cidade através da aplicação de uma metodologia de análise. O município escolhido como estudo de caso é Porto Alegre, por ser uma cidade que se comprometeu em estabelecer mudanças para reduzir as emissões dos gases de efeito estufa, contudo, sem ainda possuir um plano de ação definido. A metodologia do trabalho é qualitativa e quantitativa e foi dividida em três etapas principais: a revisão bibliográfica, o desenvolvimento da metodologia de análise do sistema energético urbano e a aplicação da metodologia proposta. A revisão bibliográfica forneceu a base teórica para o desenvolvimento da metodologia de análise do sistema energético urbano. Esta metodologia prevê o levantamento de dados diversos que se complementam e, dessa forma, possibilitam uma análise integrada e mais aprofundada do sistema energético da cidade. Para tanto, a análise do sistema energético foi dividida em três etapas: caracterização municipal, análise da demanda de energia e levantamento da oferta das principais fontes energéticas locais. Para esta última etapa, visando um exercício concreto de avaliação, especificou-se o potencial de produção de eletricidade através do recurso solar. Os principais resultados da análise do sistema energético de Porto Alegre, entre os anos 2005 e 2014, destacam que o consumo de energia cresceu oito vezes mais que o aumento populacional e menos que a metade do PIB da cidade. Igualmente, no mesmo período, a frota de veículos, assim como o consumo de gasolina, aumentou 13 vezes mais que a população. Entre os setores econômicos analisados o setor transporte foi responsável, em 2014, pelo consumo de 60% da demanda final de energia da cidade. Nesse ano, a fonte de energia mais consumida foi a eletricidade, representando 28,1% do consumo final. Ainda analisando os dados de 2014, verificou-se que o consumo de eletricidade per capita de Porto Alegre pode ser considerado alto, 2,58 MWh/per capita, se igualando ao do Brasil e ao de alguns países desenvolvidos. Em relação ao potencial de produção de eletricidade, a partir da fonte solar, estimou-se um potencial de 2.549 GWh/ano, considerando todo o território da cidade, e de 772 GWh, considerando apenas o território que possuem edificações, aproximadamente 30% da cidade. Isto significa que se todos os consumidores residenciais e comerciais produzissem sua própria energia poderiam ser gerados 2.892 GWh por ano em Porto Alegre. Essa energia seria capaz de suprir 75,8% de toda a demanda de eletricidade da cidade em 2014. Ao final, ressaltou-se a importância de articular o planejamento energético ao planejamento urbano e ao plano de mobilidade urbana, uma vez que o sistema energético urbano está relacionado com os demais. / Nowadays cities at are the epicenter of an energetic transformation. Today, they are the main consumers of matter and energy. Most of that energy supplied through a conventional, centralized and inefficient system. Thus, it is in urban centers that strategic energy efficiency and energy conservation can be better implemented. However, before municipalities commit to new policy initiatives and investments, the first step is to improve understanding of the local energy system. Therefore, the central objective of this research is to understand in a more integrated way the energy system of a city through the application of a methodology of analysis of an urban energy system. The municipality chosen as a case study is Porto Alegre. It was chosen because is a city that has committed itself to establishing changes to reduce emissions of greenhouse gases, however, it does not have a defined plan of action. The methodology of the work is qualitative and quantitative and was divided into three main stages, among them: literature review, development of the methodology of urban energy system analysis, and application of the proposed methodology. The literature review provided the theoretical basis for the development of the methodology of analysis of the urban energy system. This methodology determines the collection of diverse data that complement each other and, thus, enable an integrated and more in-depth analysis of the city\'s energy system. In order to do so, the analysis of the energy system was divided into three stages: municipal characterization, analysis of the energy demand and survey of the supply of the main local energy sources. For this last stage, aiming a specific evaluation exercise, was specified the potential of electricity production through the solar resource.The main results of the analysis of the energy system of Porto Alegre, between 2005 and 2014, highlight that energy consumption grew eight times more than the population increase and less than half of the city\'s GDP. Also, in the same period, the car fleet grew 13 times more than the population. Among the economic sectors analyzed, the transportation sector was responsible for the consumption of 60% of the final energy demand of the city, in 2014. In that year, the most consumed energy source was electricity, representing 28.1% of final consumption. The per capita electricity consumption in Porto Alegre was considered high, 2.58 MWh/per capita, which equals that of Brazil and some developed countries. Regarding the potential for electricity production, it was determined a potential of 2,549 GWh/year (considering the entire territory of the city), and 772 GWh (considering only the territory that have buildings, approximately 30% of the city). This means that if all residential and commercial consumers produced their own energy could generate 2,892 GWh per year in Porto Alegre. This energy would be able to supply 75.8% of all city electricity demand. In the end, it was emphasized the importance of unifying the energy planning to the urban planning and to the urban mobility plan, since the urban energy system is related to both.
2

Análise integrada do sistema energético urbano: estudo de caso da cidade de Porto Alegre / Integrated analysis of the urban energy system: case study of the city of Porto Alegre

Natália de Assis Brasil Weber 20 March 2017 (has links)
Nos dias atuais as cidades são o epicentro de uma transformação energética, pois, são elas as principais consumidoras de matéria e energia. Energia fornecida, em sua maioria, através de um sistema convencional, centralizado e ineficiente. Dessa forma, são nos centros urbanos que poderão ser melhor implementadas estratégicas de eficiência energética e conservação de energia. Contudo, antes que os municípios se comprometam com novas iniciativas políticas e investimentos, o primeiro passo é melhorar a compreensão do sistema energético local. Por conseguinte, o objetivo central desta pesquisa é compreender de forma mais integrada o sistema energético de uma cidade através da aplicação de uma metodologia de análise. O município escolhido como estudo de caso é Porto Alegre, por ser uma cidade que se comprometeu em estabelecer mudanças para reduzir as emissões dos gases de efeito estufa, contudo, sem ainda possuir um plano de ação definido. A metodologia do trabalho é qualitativa e quantitativa e foi dividida em três etapas principais: a revisão bibliográfica, o desenvolvimento da metodologia de análise do sistema energético urbano e a aplicação da metodologia proposta. A revisão bibliográfica forneceu a base teórica para o desenvolvimento da metodologia de análise do sistema energético urbano. Esta metodologia prevê o levantamento de dados diversos que se complementam e, dessa forma, possibilitam uma análise integrada e mais aprofundada do sistema energético da cidade. Para tanto, a análise do sistema energético foi dividida em três etapas: caracterização municipal, análise da demanda de energia e levantamento da oferta das principais fontes energéticas locais. Para esta última etapa, visando um exercício concreto de avaliação, especificou-se o potencial de produção de eletricidade através do recurso solar. Os principais resultados da análise do sistema energético de Porto Alegre, entre os anos 2005 e 2014, destacam que o consumo de energia cresceu oito vezes mais que o aumento populacional e menos que a metade do PIB da cidade. Igualmente, no mesmo período, a frota de veículos, assim como o consumo de gasolina, aumentou 13 vezes mais que a população. Entre os setores econômicos analisados o setor transporte foi responsável, em 2014, pelo consumo de 60% da demanda final de energia da cidade. Nesse ano, a fonte de energia mais consumida foi a eletricidade, representando 28,1% do consumo final. Ainda analisando os dados de 2014, verificou-se que o consumo de eletricidade per capita de Porto Alegre pode ser considerado alto, 2,58 MWh/per capita, se igualando ao do Brasil e ao de alguns países desenvolvidos. Em relação ao potencial de produção de eletricidade, a partir da fonte solar, estimou-se um potencial de 2.549 GWh/ano, considerando todo o território da cidade, e de 772 GWh, considerando apenas o território que possuem edificações, aproximadamente 30% da cidade. Isto significa que se todos os consumidores residenciais e comerciais produzissem sua própria energia poderiam ser gerados 2.892 GWh por ano em Porto Alegre. Essa energia seria capaz de suprir 75,8% de toda a demanda de eletricidade da cidade em 2014. Ao final, ressaltou-se a importância de articular o planejamento energético ao planejamento urbano e ao plano de mobilidade urbana, uma vez que o sistema energético urbano está relacionado com os demais. / Nowadays cities at are the epicenter of an energetic transformation. Today, they are the main consumers of matter and energy. Most of that energy supplied through a conventional, centralized and inefficient system. Thus, it is in urban centers that strategic energy efficiency and energy conservation can be better implemented. However, before municipalities commit to new policy initiatives and investments, the first step is to improve understanding of the local energy system. Therefore, the central objective of this research is to understand in a more integrated way the energy system of a city through the application of a methodology of analysis of an urban energy system. The municipality chosen as a case study is Porto Alegre. It was chosen because is a city that has committed itself to establishing changes to reduce emissions of greenhouse gases, however, it does not have a defined plan of action. The methodology of the work is qualitative and quantitative and was divided into three main stages, among them: literature review, development of the methodology of urban energy system analysis, and application of the proposed methodology. The literature review provided the theoretical basis for the development of the methodology of analysis of the urban energy system. This methodology determines the collection of diverse data that complement each other and, thus, enable an integrated and more in-depth analysis of the city\'s energy system. In order to do so, the analysis of the energy system was divided into three stages: municipal characterization, analysis of the energy demand and survey of the supply of the main local energy sources. For this last stage, aiming a specific evaluation exercise, was specified the potential of electricity production through the solar resource.The main results of the analysis of the energy system of Porto Alegre, between 2005 and 2014, highlight that energy consumption grew eight times more than the population increase and less than half of the city\'s GDP. Also, in the same period, the car fleet grew 13 times more than the population. Among the economic sectors analyzed, the transportation sector was responsible for the consumption of 60% of the final energy demand of the city, in 2014. In that year, the most consumed energy source was electricity, representing 28.1% of final consumption. The per capita electricity consumption in Porto Alegre was considered high, 2.58 MWh/per capita, which equals that of Brazil and some developed countries. Regarding the potential for electricity production, it was determined a potential of 2,549 GWh/year (considering the entire territory of the city), and 772 GWh (considering only the territory that have buildings, approximately 30% of the city). This means that if all residential and commercial consumers produced their own energy could generate 2,892 GWh per year in Porto Alegre. This energy would be able to supply 75.8% of all city electricity demand. In the end, it was emphasized the importance of unifying the energy planning to the urban planning and to the urban mobility plan, since the urban energy system is related to both.
3

Omställning – Tillväxt – Effektivisering : Energifrågor vid renovering av flerbostadshus

Thoresson, Josefin January 2015 (has links)
Flerbostadshus anses viktiga för att minska energianvändningen i byggnader, och potentialen att energieffektivisera i samband med renovering är stor. Denna studie behandlar hur arbete med energifrågor genomförs i renovering av flerbostadshus byggda under miljonprogrammet i stadsdelen Östra Sätra i Gävle. Avhandlingens analytiska verktyg baseras på perspektiv utvecklade inom teknik och vetenskapsstudier (STS) och aktörsnätverksteori (ANT) samt urbana studier. I studien utvecklas och tillämpas verktyget energisammansättningar. Genom en symmetrisk ansats studeras energifrågors definition och innehåll i renoveringen genom att spåra kedjor av översättningar. Det empiriska underlaget är kvalitativa intervjuer, mål- och strategidokument, beslutsprotokoll och observationer. Avhandlingen visar att energiarbetets innehåll flätades samman med exempelvis kommunal planering och energipolitik, med bostadsbolagets befintliga arbetssätt för renoveringar och dess relationer till sina kunder, samt med lagen för allmännyttiga bostadsbolag. Studien identifierar också att spänningar uppstod i energiarbetet inom flera områden. Dessa rör hur de ekonomiska vinsterna och kostnaderna för energiarbete ska beräknas och fördelas, översättningar av energimål, var och hur energiarbete ska prioriteras i den bebyggda miljön, i vilken takt energiarbetet ska ske och hur de boende ska delta i energiarbete. Studien visar att energieffektiviserande åtgärder prioriterades i renoveringen så länge som de beräknades vara ekonomiskt affärsmässiga och en del av det allmännyttiga arbetet, men även hur förändringar var svåra att genomföra om de utmanade eller förändrade befintliga relationer och arbetssätt. Det gällde särskilt i relationen till de boende i området och till ekonomiska kostnader för renoveringen. / Transforming the energy used in apartment buildings have become increasingly important issues. This study examines how energy issues were designed in a refurbishment project for apartment buildings built during the “Million Programme” era in Sweden in the district of Östra Sätra in Gävle. The analytical approach and tools used are based on science and technology studies (STS), actor–network theory (ANT), and urban studies. Specifically, the study applies the concept of assemblages, which in this study are called energy assemblages. Energy issues are examined as they translated and negotiated in practice by actors and how they are incorporated into the refurbishment design. The empirical data are based on qualitative interviews, analyses of documents, and observations. The analyses demonstrate that work on energy issues was intertwined with the city’s work on planning and energy issues, the housing company’s working practices, as well as the laws governing public housing companies. The study also demonstrates that sometimes tensions arose in situations in which different energy assemblage processes collided. The study identifies several areas of tension. First, tensions arose in situations of diverse translations of energy goals. Second, in negotiations about calculations of the financial costs of energy transition. Third, tensions also arose when determining where energy transition should be located. Fourth, about resident participation in energy issues. Fifth, the energy transition timeframe. The study demonstrates that energy efficiency measures were prioritized in the refurbishment as long as they were treated as financially beneficial and did not challenge or change existing relationships, work practices, and customer relations.
4

Sustainable Urban Energy Transition for the City of Bitola, North Macedonia : A City-Scale Urban Building Energy Model

Andersson, Emilie, Höijer, Hillevi January 2023 (has links)
Cities play a crucial role in sustainable energy system transformation. Urban energy systems account for 75% of global primary energy use, and 70% of global greenhouse gas (GHG) emissions (IEA, 2021). There is currently a large, untapped potential for reducing both energy demand and emissions by focusing measures on one of the largest consumers of energy: buildings. In North Macedonia, there is an estimated energy savings potential of 57% in the residential sector, and 29% in the public service sector (Apostolska et al., 2020). In the midst of the country’s ambitious targets of decreasing energy demand and GHG reductions, the city of Bitola is in the process of developing an action plan for a sustainable transition of the city. For this purpose, there is a need to investigate the current challenges in the energy system of the city and to evaluate potential future pathways to address these challenges, with a focus on the built environment. In this thesis, a city-scale urban building energy model (UBEM) of the city of Bitola was developed using the software City Energy Analyst (CEA). This involved modeling a total of 14 024 buildings in the city ranging from residential buildings to commercial and industrial facilities. Out of these 14 024 buildings, 10 792 were included in the analysis after excluding abandoned buildings which account for an estimated 25% of the total residential building stock. One Baseline scenario based on the current energy use in the built environment in the city, and four scenarios investigating building retrofit measures and alternative heating solutions were developed for the time period 2023-2040 which were then assessed based on three key performance indicators (KPIs). A 2% implementation rate was used for the measures included in the scenarios, resulting in a total of 34% of the buildings being included in the scenario assessment. The scenarios included in the analysis are Business-as-Usual (BAU), decentralized natural gas boilers (NGB), district heating (DH) and decentralized heat pumps (HP). The KPIs include the total primary energy demand, the total operational CO2 emissions, and the economic performance of the system, measured as a net present value (NPV). All scenarios were also evaluated with and without solar photovoltaic (PV). The results showed the BAU scenario to be the lowest performing scenario for all three KPIs, while the HP scenario showed to be the best-performing scenario regarding the reduction of energy demand and CO2 emissions, with a 99% reduction of CO2 emissions and a 65% lower energy demand than in the baseline year. However, this comes at a relatively high cost compared to the other scenarios. The DH and NGB scenarios performed moderately regarding demand and CO2 emission savings while performing better from an economic standpoint. All scenarios showed a low share of buildings on an individual level having a positive NPV, thus failing to reach a positive total NPV for the entire system. On the other hand, the sensitivity analysis demonstrated how a reduction of the capital expenditure (CAPEX) led to a positive NPV for all scenarios with PV, and for all scenarios except BAU without PV. This indicates that subsidies provided by local or national stakeholders could result in a profitable investment. Two important conclusions can be drawn from the results: firstly, taking any action and implementing either of the HP, NGB and DH scenarios will be more beneficial than taking no action, and secondly, the sustainable development of the city needs to be led by the local municipality, as well as national stakeholders to enable a long-lasting transition. / Städer spelar en avgörande roll för omställningen till hållbara energisystem. Energisystem i städer står för 75% av den globala primära energianvändningen och 70% av de globala växthusgasutsläppen (IEA, 2021). För närvarande finns det en stor, outnyttjad potential för minskning av både energibehov och utsläpp genom att fokusera på åtgärder för en av de största energikonsumenterna: byggnader. I Nordmakedonien uppskattas det finnas potential för energibesparingar på 57% i bostadssektorn och 29% i offentlig sektor (Apostolska et al., 2020). I samband med landets ambitiösa mål om att minska energianvändning och växthusgasutsläpp genomgår staden Bitola för närvarande en process för att utveckla en handlingsplan för en hållbar omställning av staden. För detta ändamål krävs en undersökning av de aktuella utmaningarna i stadens energisystem och utvärdering av potentiella framtida riktningar för att möta dessa utmaningar, med fokus på den bebyggda miljön. I detta examensarbete utvecklades en modell i stadsskala av energianvändningen i byggnader för staden Bitola i Nordmakedonien med hjälp av programvaran City Energy Analyst (CEA). Modellen omfattade totalt 14 024 byggnader, från bostadshus till kommersiella och industriella fastigheter. Då 25% av stadens bostadsbyggnader uppskattas vara övergivna ingick totalt 10 792 byggnader i den slutgiltiga analysen. Ett basscenario som beskriver dagens energianvändning i byggnaderna, och fyra framtida scenarier, som omfattar energieffektiviseringsåtgärder och alternativa värmesystem, utvecklades för tidsperioden 2023-2040. En implementeringstakt om 2% av byggnadsbeståndet, vilket resulterade i att totalt 34% av byggnadsbeståndet inkluderades i scenarioanalysen. De fyra framtida scenarierna som ingick i analysen är Business-as-Usual (BAU), decentraliserade gasvärmepannor (NGB), fjärrvärme (DH) och decentraliserade värmepumpar (HP). Scenarierna bedömdes med hjälp av tre nyckeltal (KPI:er): den totala primärenergianvändningen, de totala operativa CO2 utsläppen och den ekonomiska prestandan, mätt som investeringens nu värde (NPV). Samtliga scenarier utvärderades med och utan implementering av solceller. Resultaten visade att scenariot BAU presterade sämst för alla tre KPI:er, medanHP-scenariot visade sig vara det bäst presterande scenariot för minskning avenergibehovet och CO2-utsläppen, med 99% minskning av CO2-utsläpp och 65%lägre energianvändning jämfört med basscenariot. Dock är detta förknippat medrelativt höga kostnader jämfört med de andra scenarierna. DH- och NGB-scenariotpresterade måttligt gällande besparing av energibehov och CO2-utsläpp, samtidigt somde presterade bättre ur ett ekonomiskt perspektiv. Alla scenarier resulterade i en lågandel av byggnader på individuell nivå med ett positivt NPV, vilket innebär att demisslyckas med att nå ett positivt totalt NPV för hela systemet. Å andra sidan visadekänslighetsanalysen att en minskning av investerings kostnaderna (CAPEX) ledde tillett positivt NPV för alla scenarier med solceller, och för alla scenarier utom BAU utan solceller. Detta indikerar att subventioner från lokala och nationella aktörer kan leda till en lönsam investering. Två viktiga slutsatser kan dras från dessa resultat: för det första, att vidta åtgärder och implementera något av HP-, NGB- eller DH-scenariot är mer fördelaktigt än att inte vidta några åtgärder, och för det andra, behöver den hållbara utvecklingen av staden ledas av den lokala kommunen samt nationella aktörer för att möjliggöra en långvarig omställning.
5

La transition énergétique urbaine : vers une reconfiguration multi- niveaux des systèmes de gouvernance et des systèmes énergétiques ? : Deux études de cas contrastées : Bristol (Royaume-Uni) et Munich (Allemagne) / Urban energy transition : towards a multi-level reorganization of governance and energy systems ? : Two contrasted case studies : Bristol (United Kingdom) and Munich (Germany)

Mor, Elsa 25 September 2015 (has links)
La thèse porte sur les processus de transition énergétique urbaine et leur caractère multi-niveaux. Sachant que les processus de transition ne peuvent être pensés indépendamment du contexte local dans lequel ils évoluent et qu’ils se construisent en interaction avec les autres niveaux d’action, leur compréhension appelle une analyse multi-niveaux, mettant en lumière les articulations en jeu entre les échelles de décision et d'action. La première partie montre que le caractère systémique et transversal des enjeux climat-énergie complexifie les processus de gouvernance et participe à leur reconfiguration à toutes les échelles d’action, remettant en question les cadres conceptuels et les champs disciplinaires conventionnels. Les deuxième et troisième parties mobilisent des études de cas contrastées, Munich et Bristol. Cette analyse révèle un choc des modèles de transition, entre Bristol, privilégiant une stratégie de décentralisation et de résilience énergétique, portée par la municipalité, les communautés énergétiques et les acteurs industriels, et Munich, adoptant une stratégie de délocalisation de la production d’électricité et d’internationalisation des activités de la régie municipale d’énergie (SWM) – 7ème géant allemand. On observe à l’échelle locale et non sans paradoxe une inversion des dynamiques et des modèles énergétiques nationaux. Le centralisme britannique agit comme une contrainte structurante sur la stratégie décentralisée de Bristol ; tandis qu'à Munich, l’Energiewende est un catalyseur pour la stratégie industrielle délocalisée de la SWM, qui devient en retour un acteur majeur de la transition fédérale au vu de son envergure. / The PhD addresses the processes of urban energy transition and their multi-level dimension. Given that these processes cannot be considered independently from the local context in which they apply and that they are built in interaction with the other levels of action, understanding them calls for a multi-level analysis to shed light the articulations between the different scales of decision and action. The first part shows that the systemic and cross-cutting nature of the climate-energy issues makes governance processes more complex and contributes to their reorganization at all scales of action by questioning the standard conceptual frameworks and disciplinary fields. The second and third parts develop mixed case studies, Munich and Bristol. This analysis reveals a contrast in the transition models, between Bristol, which favors a strategy of decentralization and energy resilience supported by the municipality, the energy communities and the industrial actors, and Munich, which adopts a strategy organized around the relocation of electricity generation and the internationalization of activities of the municipal energy company (SWM) – 7th largest German producer. A reversal of the dynamics and national models of energy is paradoxically observed between the national and the local scales. The UK centralism acts as a structural constraint for the decentralized strategy of Bristol, in Munich, the EnergieWende is a driver for the industrial and delocalized strategy of the SWM, which becomes a major player in the federal transition given its scale.

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