• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 17
  • 10
  • 4
  • 4
  • 2
  • 2
  • Tagged with
  • 40
  • 40
  • 11
  • 8
  • 7
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 6
  • 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.
31

Techno-Economic Analysis of Wind Power-to-Hydrogen / Teknoekonomisk analys av vindkraft-till-vätgas

Muhsin, Zeinab January 2023 (has links)
I Sverige har målet länge varit att reducera mängden växthusgasutsläpp från transportsektorn [1]. Ambitionen har därför varit att försöka fasa ut användningen av fossila bränslen som till exempel diesel. Det har bland annat gjorts genom att öka andelen elbilar och skapa förutsättningar för det genom att etablera en storskalig infrastruktur för laddningsstationer runtom i landet. På senare tid har intresset för vätgas som ett potentiellt drivmedel för fordon ökat markant. Detta har i sin tur motiverat olika aktörer (industri, akademi, transportsektor och offentliga sektor) i Mellansverige att ingå i ett partnerskap för att tillsammans vidareutveckla detta mål genom att initiera samverkansprojektet ”Mid Sweden Hydrogen Valley”. Projektets ambition är att utforma och driva storskalig vätgasproduktion i syfte att bland annat stegvis introducera vätgasdrivna transportmedel i Gävle hamn som ett alternativ till nuvarande dieseldrivna fordon i hamnen. Detta då vätgasdrivna fordon erbjuder grön transport, längre körsträcka, snabbare påfyllningstid samt en viktmässigt lättare bränslelager jämfört med tunga batterier i elbilar. För att uppnå detta måste först vätgasinfrastruktur etableras för att skapa en tillgänglighet och därför har Mellansverige som huvudmål att ta en ledande roll.  Detta masterprojekt hade som mål att utforma och undersöka om en storskalig vätgasproduktionsanläggning som drevs på förnybar energi (vindkraft), hade potentialen att bli ekonomiskt lönsamt utifrån ett investeringskalkylsperspektiv. Detta gjordes genom att först konstruera en generell och optimerad konfiguration av en sådan anläggning. Detta tillvägagångssätt involverade bland annat att ta reda på vilka relevanta komponenter som behövdes, analysera lämpliga teknologier och undersöka komponenternas kommersiella tillgänglighet. En tekno-ekonomiskt analys tillämpades därefter på den färdigställda anläggningen. Den tekno-ekonomiska analysen genomfördes i form av en fallstudie för åren 2019, 2020 och 2021, där en fiktiv vätgasanläggning i Gävle hamn anslöts till en fiktiv havsbaserad vindkraftspark strax utanför hamnen. Denna havsbaserade vindkraft var i samma stund ansluten till nätet via en närliggande anslutningspunkt. Syftet var att ta reda på vid vilka spotpriser som funktion av vätgaspris, där det var lönsamt att producera vätgas i stället för att sälja elektriciteten direkt till elmarknaden. Dessa spotpriser räknades fram genom att subtrahera alternativintäkten av att sälja elen till nätet från vätgasens försäljningspris. Dessa spotpriser användes till att erhålla antalet lönsamma produktionstimmar av vätgas. Baserat på dessa lönsamma produktionstimmar kunde den totala generade inkomsten av vätgasförsäljning kalkyleras. Den slutliga vinsten beräknades genom avdrag av anläggningens fasta kostnader från den genererade rörliga inkomsten. Denna fallstudie är baserad på en djupgående litteraturstudie samt kontakt med Svenska Kraftnät (SvK), Energimyndigheten, diverse vindkraftsproducenter och Svea Vind Offshore. Tre varianter av fallstudien skapades där den enda skillnaden var storlekarna på huvudkomponenterna PEM elektrolys, kompressor, lager och vätgastankstation. I denna rapport valdes följande tre elektrolyskapaciteter: 5 MW, 10 MW och 20 MW.  Resterande komponenter dimensionerades utifrån elektrolysens kapacitet. Anledningen till att tre olika anläggningsvarianter studerades var för att ta reda på om det fanns ett tydligt samband mellan anläggningens storlek och sannolikheten att uppnå ekonomisk lönsamhet. Resultaten visade att dessa tre anläggningsstorlekar bar på olika för- och nackdelar. Fördelen som en 5 MW anläggning hade var till exempel flest antal produktionstimmar men nackdelen att den producerade minst mängd av vätgas. En 20 MW anläggning hade minst antal produktionstimmar men störst vätgasproduktion vilket resulterade i höga vinster. Enligt vad som kan förväntas låg 10 MW-anläggningen mellan 5 MW och 20 MW när det kom till antalet produktionstimmar och genererad vinst. Denna information var dock inte tillräcklig för att utfärda en slutlig bedömning gällande vilken anläggning som hade störst potential att uppnå lönsamhet. Detta grundade sig i att alla dessa anläggningsvarianter var enkelt konstruerade, vilket innebar att många mindre komponenter som också har en teknisk och ekonomisk inverkan, inte togs med i beräkningarna. Utöver detta så antogs även att anläggningen arbetade helt isolerat, vilket innebar att inget vätgasläckage ägde rum, något som inte överensstämmer i praktiken. / The goal to reduce emissions of greenhouse gases from the transportation sector in Sweden, has been ongoing for a while [1]. Therefore, the ambition to phase out the usage of fossil fuels such as diesel, has been actively taking place through different strategies. One such strategy is to increase the share of electric cars and apply a major effort in establishing a large-scaled infrastructure for charging stations throughout the country. Recently, interest in hydrogen as a potential fuel has significantly increased. This has in turn motivated different actors (industry, academia, transport, and public sector) in mid Sweden to form a partnership to further develop this goal by initiating a collaborative project called "Mid Sweden Hydrogen Valley”. The project’s ambition is to construct and operate a large-scale hydrogen production facility with the aim of, among other things, gradually introducing hydrogen fueled vehicles in Gävle harbor. The hydrogen fueled vehicles will pose as alternatives to current operating diesel fueled vehicles in the harbor. The plausible reasons for hydrogen fuel in the transport sector is that it offers green transport, longer driving distances, faster refueling time, and a lightweight fuel storage compared to the heavy batteries in electric cars. To achieve this, hydrogen infrastructure must first be established to create accessibility. Thus, the collaboration in mid Sweden has the mission of taking a leading role in this matter.  The aim of this master thesis is to investigate whether a large-scale hydrogen production facility powered by renewable energy (wind energy) has the potential of becoming economic viable from the perspective of an investment calculation. This investigation was executed by firstly constructing a generalized and optimized configuration of such a facility, which, in turn, was accomplished by analyzing what type of relevant equipment that was needed, studying, and selecting appropriate technologies, and examining the commercial availability of the equipment. Thereafter, a techno-economic analysis on the facility’s operational process was applied. This analysis was conducted in the form of a case study for the following target years 2019, 2020 and 2021, where a hydrogen production plant was placed in Gävle harbor and was connected to a hypothetical offshore wind farm, situated just outside the harbor. This offshore wind farm was simultaneously connected to the grid via a nearby connection point. The purpose was to determine which spot prices, as a function of different hydrogen prices, made it possible to produce and sell hydrogen at a profit rather than selling the electricity directly to the grid. These breakeven spot prices were computed by subtracting the alternative revenue of selling electricity to the grid from the selling price of hydrogen. Thereafter, these spot prices were used to obtain the profitable number of hydrogen production hours. Based on these hydrogen production hours, the total variable income generated from selling hydrogen could be calculated. Finally, the actual profit was calculated by deducting the facility's fixed costs from the generated income. This case study was based on an in-depth literature research and contact with Svenska Kraftnät (SvK), the Swedish Energy Agency, different wind power producers, and Svea Vind Offshore. Three variants of the case study were produced, where the only difference were the sizes of the main components: PEM electrolysis, compressor, storage, and hydrogen refueling station. In this report, the following three electrolyzer capacities 5 MW, 10 MW, and 20 MW, were selected. The dimensions of the other components were based on the electrolyzer’s capacity. The reason for producing three different facility sizes, was to determine whether there was a correlation between facility size and the probability of achieving economic profitability. The results showed that these three facilities possessed different advantages and drawbacks. The 5 MW facility had the advantage of obtaining the highest number of productions hours but had the drawback of generating the least volume of hydrogen. However, the 20 MW facility had the fewest production hours but the highest volume of hydrogen production, resulting in high profits. Lastly, the 10 MW facility fell between the 5 MW and 20 MW in terms of the number of production hours and generated profit. However, this information was not sufficient to make a final deciding of which facility size possessed the highest chance of achieving profitability. The reason for this is that the technical and economic impact of small components were disregarded in the calculations. Additionally, these facilities were also assumed to operate with perfect insulation, meaning no occurrence of hydrogen leakage took place, which is not realistic in practice.
32

Energy, Environment and Transportation : An Actor-Role Network Analysis of the World Energy Outlook 1977-2016

Söderqvist, Felicia January 2019 (has links)
This thesis explores how energy and environmental issues have been presented in the transportation sector over time in World Energy Outlook (WEO) publications; the flagship publication of the International Energy Agency (IEA). The thesis covers WEO publications from the first publication of 1977 up to 2016 (with the exception of WEO 1982). The data was extracted through the aid of interpretive content analysis, focusing on the transport sector. Energy and Environmental issues within the context of transportation were then discussed as to their roles and forms of action they were ascribed throughout the publications. Actor-network theory was used as a theoretical framework to map and showcase how these roles and actions conditioned and connected to each other. The results of the study show that energy has had a tendency to be divided into the camps of fuels that are either solutions or problems. The exceptions are biofuels, which stand out as fuels that are both solutions and problematic. The environmental issues are solved and caused through energy use, and in 1977,environmental consideration were presented as obstacles to energy security. In 1993 global warming and emissions have changed into being major policy concern. Pollution, congestion, dust, noise, and related health issues are added to the fray as time proceeds, and so are more forms of energy for solutions. Goals and interests showcased in the publications are shown to conflict with others, while energy efficiency as a solution has emerged as a solution to both global warming and energy security. The transport sector starts of as framed more asan area or space where environmental issues take place and solutions are implemented,however, increasing motorisation of the sector and traffic and its role as amajor emitter are later added as active aspects of the conditioning of thesector and in offsetting the solutions. Regional cases are used to exemplify the issues and solutions, with a major focus on OECD contexts, and technological renewal emerges early on as a mayor pathway in solving the environmental issues, through the support of consumers. However, the major issues still remain the same as in 1993.
33

Management podniku a životní prostředí / Business Management and Environment

Romaňáková, Dita January 2008 (has links)
The Thesis provides an overview of environmental management issue and its practical application. The aim of this work is to find out the readiness of a particular company to establish Environmental Management Systems (EMS) and to review, whether the company is prepared for such a change, able to keep and improve the systems. The Thesis contains theoretical background of environmental management including all demands necessary for a company to introduce environmental management into a practice. Acquired information is applied to a selected company, which is a transport company VK-SPED spol. s. r. o. Practical part comprises a study of ecological status of the company via defined analyses and exploration of the environmental profile of the company. This process discovers the potential and ability of the company to implement EMS. Furthermore, the instruction for implementing EMS into a particular company follows. Finally, the results of the work are summarized and a recommendation for a proper environmental management is offered.
34

Rättvisa på väg : En granskning av miljörättvisa i strategier för omställningen till fossiloberoende transportsektor i Jönköpings län / The road to justice : A review of environmental justice in strategies for the transition to fossil-independent transport in Jönköping region

Wetter, Linda, Sundholm, Oskar January 2020 (has links)
The aim of this paper is to investigate how strategies and plans for the transition to a fossil-free transport sector take environmental justice into account in these plans at a regional level. This is based on a theoretical framework of environmental justice and a legal geographical perspective. The empirical material that forms the basis of the study has been produced through qualitative content analysis of regional and municipal plans and strategies as well as semi-structured interviews with actors in the transition. In order to achieve the purpose, the strategies that emerged in the documents were examined, as well as how actors reasoned about these strategies with the help of environmental justice perspectives. The study has focused on an area where a knowledge gap has been identified in the literature. The result shows that there is no clear perspective of environmental justice in the plans and strategies in the Jönköping region and that the regional strategies needs to take more account of the just perspectives in the transition. This is achieved through different forms of justice: distributive, procedural, recognition and restorative. / Syftet med studien är att undersöka hur strategier och planer för omställningen till en fossilfri fordonssektor tar hänsyn till miljörättvisa i dessa planer på en regional nivå. Detta utifrån ett teoretiskt ramverk baserat på miljörättvisa och ett juridisk geografiskt perspektiv. Det empiriska material som ligger till grund för studien har tagits fram genom kvalitativ innehållsanalys av regionala och kommunala planer och strategier samt semistrukturerade intervjuer med aktörer i omställningen. För att uppnå syftet undersöktes vilka strategier som framträdde i dokumenten, samt hur aktörer resonerade kring dessa strategier med hjälp av perspektiv av miljörättvisa. Studien har fokuserat på ett område där en kunskapslucka har kunnat konstaterats i tidigare forskning. Resultatet visar att det saknas ett tydligt perspektiv av miljörättvisa i planerna och strategierna i Jönköpings län och att det behövs tas större hänsyn till rättviseperspektiven i dessa. Detta uppnås genom olika former av rättvisa: fördelande, deltagande, erkännande och reperativ.
35

Propuesta del uso combinado de Base Macadam con Geotextiles No Tejidos en el proceso constructivo y diseño de la base del pavimento flexible con el fin de reducir los asentamientos en Chorrillos, Lima / Proposal for the combined use of Macadam Base with Non-Woven Geotextiles in the construction process and design of the flexible pavement base in order to reduce settlements in Chorrillos, Lima

Gallardo Quiroz, Angel Manuel, Lopez Cruz, Lizette Alessandra 20 January 2022 (has links)
La siguiente investigación tiene como fin colocar al Perú en una posición competitiva a nivel internacional mediante la mejora de su infraestructura vial, esto se plantea al proponer un sistema constructivo eficiente de la base de pavimentos flexibles en suelos blandos saturados de manera que estos no sufran grandes deformaciones permanentes y se reduzca el número y costo de mantenimientos que se aplican al pavimento. La necesidad de un mejor sistema de vías se ve reflejada en la brecha de acceso básico a la infraestructura a corto plazo en el sector Transporte. Debido a esto, se seleccionó una vía – caso de estudio que presenta serias patologías. Se pretende demostrar que la propuesta presentada en esta investigación reduce de manera considerable las deformaciones permanentes en la estructura del pavimento mediante el uso combinado de la Base Macadam y Geotextiles No Tejidos. El uso de ambos fue simulado en tramos de prueba sobre los cuales se realizaron ensayos de Deflectometría, un tramo reforzado con Geotextiles No tejidos y otro tramo sin reforzar. Se evidenciará una disminución en los asentamientos en el tramo reforzado y se elaborará un adecuado proceso constructivo basado en la construcción de las muestras usadas en los ensayos / The following research aims to place Peru in a competitive position at the international level by improving its road infrastructure, this is proposed by proposing an efficient construction system of the base of flexible pavements in saturated soft soils so that they do not suffer large permanent deformations and reduce the number and cost of maintenance applied to the pavement. The need for a better road system is reflected in the short-term basic access gap to infrastructure in the Transportation sector. Due to this, an avenue with serious pathologies in the pavement was selected. It is intended to demonstrate that the proposal presented in this investigation considerably reduces permanent deformations in the pavement structure through the combined use of Macadam base and Non-Woven Geotextiles. The use of both was simulated in test sections on which deflectometry tests were carried out, a section reinforced with Nonwoven Geotextiles and another section without reinforcement. There will be evidence of a decrease in settlements in the reinforced section and an adequate construction process based in the construction of the trials will be developed for the proposal. / Tesis
36

Policy Tools for the Decarbonisation of Urban Freight Transport in Brazil

Mandana, Raghav Somayya January 2021 (has links)
There has been an increase in the carbon dioxide (CO2) emissions in the last 3 decades. A large share of these emissions is produced by the transport sector. In 2010 alone, global transport accounted for 7 GtCO2 eq and approximately 23% of total energy-related CO2 emissions. In order for the decarbonisation of the transport sector, one of the most important strategies is to reduce the use of fossil fuels. Fossil fuel consumption can be reduced by rolling out more battery electric vehicles (BEVs) on public roads. This is one of the methods by which the concept of electromobility is promoted. In order to increase the share of EVs, many countries have implemented different policies that promote the electrification of the transport sector. With respect to freight transport, electric commercial vans are one of the feasible choices.  This Master thesis involves a quantitative study which focus on the “total cost of ownership” (TCO) of light commercial vehicles (LCVs). Two diesel vans currently used in Curitiba, Brazil were selected - the Sprinter van by Mercedes-Benz and the Master van by Renault. In addition, their electric counterparts were also chosen; in conjunction, a sensitivity analysis with respect to fuel prices and annual distance driven was conducted. The results showed that the TCO of the electric LCVs is around 1.6 to 1.7 times higher than their diesel versions. As far as the two van model types were concerned, the Mercedes-Benz Sprinter had a higher TCO than the Renault Master over the chosen vehicle lifetime for both the diesel and electric versions, with the difference around 7.5% for the diesel versions and approximately 13% for the electric versions.  Based on the results of the TCO study, possible economic policies and fiscal instruments were recommended with regards to light commercial freight transport for Curitiba. / Det har skett en ökning av koldioxidutsläppen (CO2) under de senaste 3 decennierna. En stor del av dessa utsläpp produceras av transportsektorn. Bara 2010 svarade, global transport för 7 GtCO2 ekvivalenter och cirka 23% av de totala energirelaterade koldioxidutsläppen. För att avkolning av transportsektorn är en av de viktigaste strategierna att minska användningen av fossila bränslen. Fossil bränsleförbrukning kan minskas genom att rulla ut fler elektriska fordon (EF) på allmänna vägar när det gäller transportsektorn i allmänhet. Detta är en av metoderna som begreppet elektromobilitet främjas. För att öka andelen elbilar har många länder genomfört olika policyer som främjar elektrifiering av transportsektorn. När det gäller godstransport, är elektriska kommersiella lastbilar och skåpbilar två av de möjliga valen.  Detta examensarbete involverar en kvantitativ studie som fokuserar på “totala ägandekostnaderna” (TÄK) för lätta nyttofordon. Två dieselbilar som för närvarande används i Curitiba, Brasilien valdes - Sprinter-skåpbilen från Mercedes-Benz och Master-skåpbilen av Renault. Dessutom valdes deras elektriska motsvarigheter; i samband med detta genomfördes en känslighetsanalys avseende bränslepriser och årlig körd distans. Resultaten visade att T för elektriska LCV är cirka 1.6 till 1.7 gånger högre än deras dieselversioner. När det gäller de två typerna av skåpbilar hade Mercedes-Benz Sprinter en högre TCO än Renault Master under den valda fordonstiden för både diesel - och elektriska versioner, med skillnaden cirka 7.5% för dieselversionerna och cirka 13% för de elektriska versionerna.  Baserat på resultaten av TCO-studien rekommenderades möjlig ekonomisk politik och finanspolitiska instrument när det gäller lätt kommersiell godstransport för Curitiba.
37

The impact of the NIS 2 directive on subcontractors in the transportation sector

Sandström, Isabel January 2024 (has links)
This study examines the impact of the NIS2 Directive on subcontractors in the transport sector, a critical infrastructure. By focusing on small and medium-sized enterprises (SMEs) operating as subcontractors, the study analyzes the challenges and obstacles these companies face in implementing the NIS2 requirements in their supply chain. The study also highlights the strategies used to ensure adequate cyber security within the transport sector's supply chain. A qualitative research method was used, where data was collected through semi-structured in-depth interviews and document analysis. The results show that companies with ISO/IEC 27001 certification have a solid foundation to meet the NIS2 requirements, while companies without such certification face greater challenges. The study also identifies the need for cooperation and knowledge sharing between companies to effectively navigate the new regulations and strengthen collective cyber security within the EU. The conclusions show that the NIS2 directive will require significant adaptations for SMEs, but also that it offers opportunities to improve their cyber security capabilities and strengthen the trust of customers and partners. The study emphasizes the importance of implementing robust information security to ensure continuity and protection of critical services, and that proactive adaptation and collaboration are key to achieving full compliance with NIS2 requirements.
38

Att spränga normer : om målstyrningsprocesser för jämställdhetsintegrering / Breaking Norms : On Management by Objectives for Gender Mainstreaming

Wittbom, Eva January 2009 (has links)
How do management control systems function when under pressure to mainstream gender equality into a core business? This question is being discussed with an interpretive approach from both the institutional and the gender perspective. Empirical evidence stems from two longitudinal case studies within the Swedish public sector where management by objectives (MBO) is the current model for governmental control. The analysis is based on four aspects: management by objectives, gender mainstreaming, the concept of loose coupling from organization studies and institutional change as translation. The gender perspective highlights constructions that tend to enable or to hamper gender equality. The sociological institutional perspective sheds light over rules, norms and culture. In the empirical cases, it becomes evident that formal goals within MBO proved unable to overrule prevailing norms that have grounded a well established gendered (malestream) culture.  Control systems are designed to handle new issues; however, in the cases studied, this took place merely normatively and in line with the core business, not by changing the grounds on which the control system stands. The MBO model consequently lacks the ability to integrate gender in a transformative mode.
39

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.
40

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.

Page generated in 0.0776 seconds