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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

Investigation into sustainable energy systems in Nordic municipalities / Utredning av hållbara energisystem i nordiska kommuner

Fischer, Robert January 2020 (has links)
Municipal energy systems in Nordic environments face multiple challenges: the cold climate, large-scale industries, a high share of electric heating and long distances drive energy consumption. While actions on the demand side minimize energy use, decarbonization efforts in mining, industries, the heating and the transport sector can increase the consumption of electricity and biofuels. Continued growth of intermittent wind and solar power increases supply, but the planned phase out of Swedish nuclear power will pose challenges to the reliability of the electricity system in the Nordic countries. Bottlenecks in the transmission and distribution grids may restrict a potential growth of electricity use in urban areas, limit new intermittent supply, peak electricity import and export. Environmental concerns may limit growth of biomass use. Local authorities are committed in contributing to national goals on mitigating climate change, while considering their own objectives for economic development, increased energy self-sufficiency and affordable energy costs. Given these circumstances, this thesis investigates existing technical and economic potentials of renewable energy (RE) resources in the Nordic countries with a focus on the northern counties of Finland, Norway and Sweden. The research further aims to provide sets of optimal solutions for sustainable Nordic municipal energy systems, where the interaction between major energy sectors are studied, considering multiple objectives of minimizing annual energy system costs and reducing carbon emissions as well as analyzing impacts on peak electricity import and export. This research formulates an integrated municipal energy system as a multi-objective optimization problem (MOOP), which is solved by interfacing the energy system simulation tool EnergyPLAN with a multi-objective evolutionary algorithm (MOEA) implemented in Matlab. In a first step, the integration or coupling of electricity and heating sectors is studied, and in a second step, the study inquires the impacts of an increasingly decarbonized transport sector on the energy system. Sensitivity analysis on key economic parameters and on different grid emission factors is performed. Piteå (Norrbotten County, Sweden) is a typical Nordic municipality, which serves as a case study for this research. The research concludes that significant techno-economic potentials exist for the investigated resources. Optimization results show that CO2 emissions of a Nordic municipal energy system can be reduced by about 60% without a considerable increase in total energy system costs and that peak electricity import can be reduced by up to 38%. The outlook onto 2030 shows that the transport sector could be composed of high electrification shares and biofuels. Technology choices for optimal solutions are highly sensitive to electricity prices, discount rates and grid emission factors. The inquiries of this research provide important insights about carbon mitigation strategies for integrated energy sectors within a perspective on Nordic municipalities. Future work will refine the transport model, develop and apply a framework for multi-criteria decision analysis (MCDA) enabling local decision makers to determine a technically and economically sound pathway based on the optimal alternatives provided, and analyze the existing policy framework affecting energy planning of local authorities. / Kommunala energisystem i nordiska miljöer möter flera utmaningar: det kalla klimatet, storskaliga industrier, en stor andel elvärme och långa distanser driver energiförbrukningen. Medan åtgärder vidtas på efterfrågesidan för att minimera energianvändningen, kan utsläppsminskande åtgärder inom gruvdrift, industrier, uppvärmningen och transportsektorn öka förbrukningen av el och biobränslen. Fortsatt tillväxt av intermittent vind- och solkraft ökar elproduktion, men den planerade avvecklingen av svensk kärnkraft kommer att utmana tillförlitligheten i elsystemet i de nordiska länderna. Flaskhalsar i överförings- och distributionsnäten kan begränsa en potentiell tillväxt av elanvändningen i stadsområden, begränsa ny intermittent utbud, och påverka elutbyte mellan länderna. Miljöhänsyn kan begränsa ökad användning av biomassa. Lokala myndigheter är engagerade i att bidra till nationella klimatmål, samtidigt som de följer sina egna mål för ekonomisk utveckling, ökad självförsörjning av energi och överkomliga energikostnader. Mot bakgrund av dessa omständigheter undersöker denna avhandling befintliga tekniska och ekonomiska potentialer för förnybar energi i Norden med fokus på de nordliga länen i Finland, Norge och Sverige. Forskningen syftar vidare till att utveckla optimala lösningar för hållbara nordiska kommunala energisystem, där samspelet mellan stora energisektorer studeras, med tanke på att minimera årliga energisystemkostnader och samtidigt minska koldioxidutsläppen samt analysera påverkan på elimport till och export från kommunen. Denna forskning formulerar ett integrerad kommunalt energisystem som multimåloptimeringsproblem (multi-objective optimisation problem - MOOP), som löses genom att kombinera simuleringsverktyget EnergyPLAN med en evolutionär algoritm implementerad i Matlab. I ett första steg studeras kopplingen av el- och värmesektorerna, och i ett andra steg effekterna av en integrerad och alltmer förnybar transportsektor på energisystemet. Känslighetsanalys på viktiga ekonomiska parametrar och på olika utsläppsfaktorer utförs. Piteå (Norrbottens län, Sverige) är en typisk nordisk kommun som fungerar som en fallstudie för detta arbete. Forskningens slutsatser innebär att det finns betydande teknisk-ekonomiska potentialer för de undersökta förnybara resurserna. Optimeringsresultaten visar att koldioxidutsläppen från ett nordiskt kommunalt energisystem kan minskas med cirka 60% utan en avsevärd ökning av de totala energisystemkostnaderna och att den högsta elimporten kan minskas med upp till 38%. Resultat för år 2030 visar att transportsektorn kan ha en mycket hög elektrifieringsgrad och samtidigt används biobränslen i tunga fordon. Optimala lösningar är mycket känsliga för elpriser, räntor och utsläppsfaktorer. Detta arbete ger viktiga insikter om strategier för koldioxidminskning för integrerade energisektorer i ett perspektiv på nordiska kommuner. Min framtida forskning kommer att förfina transportmodellen, utveckla och tillämpa ett ramverk för beslutsanalys med flera kriterier (multi-criteria decision analysis - MCDA) som ska stödja lokala myndigheter att fastställa tekniskt och ekonomiskt hållbara lösningar i deras energiplanering.
2

Nätanslutning av en framtida elväg : En kartläggning av anslutningsmöjligheter för E4an mellan Gävle och Stockholm / Grid connection of a future electric road

Ekström, Amelie, Wänlund, Jessica January 2021 (has links)
The transport sector accounts for a third of Sweden’s total greenhouse gas emissions where cars and heavy trucks dominate the use of fossil fuels. The Swedish government is now intensifying the work for an electrified transport sector where electric roads could be an important part. Electric roads enable heavy vehicles to charge their batteries while driving, which is expected to contribute to environmentally friendly and time-efficient freight transports. To implement electric roads, availability of electric power along the electric roads will be required. This study presents a plan for connecting an electric road to the electricity grid in the electricity network area of Vattenfall Eldistribution. From the results, the idea was to present general conclusions from the experiences of the study, that could contribute in further implementation of electric roads.  The road that has been selected for the study was the E4 between Gävle and Stockholm. A model for calculating the power demand along the electric road has been modeled and connection possibilities to transformer stations has been investigated. The analysis was based on three scenarios where different degrees of strengthening of the existing electricity network were assumed. In addition, a forecast for 2030 and a cost estimation for each scenario has been carried out. The result of the study indicates that for road sections close to larger cities, there are a larger number of connection options in comparison to rural areas. Furthermore, the designed solution in the study required strengthening of the electricity grid and the investment cost was 362 million Swedish crowns.
3

Nätanslutning av en framtida elväg : En kartläggning av anslutningsmöjligheter för E4an mellan Gävle och Stockholm / Grid connection of a future electric road

Wänlund, Jessica, Ekström, Amelie January 2021 (has links)
The transport sector accounts for a third of Sweden’s total greenhouse gas emissions where cars and heavy trucks dominate the use of fossil fuels. The Swedish government is now intensifying the work for an electrified transport sector where electric roads could be an important part. Electric roads enable heavy vehicles to charge their batteries while driving, which is expected to contribute to environmentally friendly and time-efficient freight transports. To implement electric roads, availability of electric power along the electric roads will be required. This study presents a plan for connecting an electric road to the electricity grid in the electricity network area of Vattenfall Eldistribution. From the results, the idea was to present general conclusions from the experiences of the study, that could contribute in further implementation of electric roads. The road that has been selected for the study was the E4 between Gävle and Stockholm. A model for calculating the power demand along the electric road has been modeled and connection possibilities to transformer stations has been investigated. The analysis was based on three scenarios where different degrees of strengthening of the existing electricity network were assumed. In addition, a forecast for 2030 and a cost estimation for each scenario has been carried out. The result of the study indicates that for road sections close to larger cities, there are a larger number of connection options in comparison to rural areas. Furthermore, the designed solution in the study required strengthening of the electricity grid and the investment cost was 362 million Swedish crowns.

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