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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

The complexity of coordination in Zimbabwe’s power sharing government (2009-2013) : the case of green fuel and restructuring of the Zimbabwe Iron and Steel Company

Nyakabawu, Shingirai January 2015 (has links)
Masters in Public Administration - MPA / This study examines the challenges of coordination in Zimbabwe’s power sharing government (2009 to 2013) between ZANU PF and the two MDC formations in the implementation of policies that cross ministerial jurisdictions under ministers from different political parties. The analysis was done through the theoretical lens of Shepsle and Laver (1996) that a cabinet minister as the political head of a major government department have the formal discretion of any policy issues under his jurisdiction and uses his or her own power to influence the substance of any specific proposals that matters within his or her own jurisdiction. I empirically examined the restructuring of the Zimbabwe Iron and Steel Company and the Green Fuel Project where the outcome of the projects required joint working between ministries controlled by different political parties. Green Fuel is a large scale ethanol producing factory constructed at a cost of US$600 million as a partnership between the Ministry of Agriculture and a private investor, but for the blended fuel to be consumed as an end product needed collaboration from the Ministry of Power and Energy Development to put out legislation enforcing mandatory blending. The Minister of Energy and Power Development ruled out mandatory blending of petrol and ethanol that left the US$600 million Green Fuels ethanol projector ground its operations and imperilled 5000 direct jobs the company had created arguing that the government does not make public policy for individuals and that the project was started without the consultation of the MDC. He also argued that the bio ethanol project affected communities in various ways including dispossession of their land, the slashing of their crops, killing of their cattle and the dispossession from their land. The restructuring of ZISCO entailed the partial sale of the government owned entity spearheaded by the Ministry of Industry and Commerce. It went through a bidding process and 54% of shares were transferred from the state to EAHL and it was renamed New Zim Steel at a ceremony presided over by the head of state. Critical to ZISCO resuming operations was the transfer of mineral rights and the Minister of Mines Obert Mpofu refused to do so arguing that he did not know about the ZISCO deal, was excluded from the negotiation process of the agreement deal despite that the agreement was concluded by cabinet. In both instances, policies that emanated from a ministry controlled by a minister of another political party did not achieve their horizontal objectives.
2

Hybridisation of fuel cells and batteries for aerial vehicles / Hybridisering av bränsleceller och batterier för obemannade luftfarkoster

Botling, Emil, Sheibeh, katrin, Wood, Martin January 2022 (has links)
There is an ever growing need for environmentally sustainable alternatives in today's society due to the looming threat of greenhouse gasses. One field where the need for new environmentally friendly solutions is needed is the aviation industry. The problem the industry is facing is due to the weight and space constraints that exist in aerial vehicles. In this bachelor project a solution for unmanned drones is proposed where it is powered by a hybrid solution consisting of batteries working together with fuel cells. The batteries compliment each other where the fuel cell is a lightweight energy source while the battery is used to combat the changing power demand. This project was done in collaboration with the Green Raven project to evaluate the optimal setup to power the energy system for an hour. The work was done theoretically in Matlab and Simulink to find the optimal system. From these simulations, data was collected to calculate the optimal configuration between batteries and amount of hydrogen stored in the Hydrogen tank. It was concluded that the best option to store the hydrogen was in a 2 liter tank at 300 bar together with 2 additional batteries with the capacity of 4000 mAh. This setup was concluded as the best option as it used up all hydrogen and landed with less charge in the battery than at the start point. / I takt med den globala uppvärmningen så växer behovet av klimatmedvetna hållbara lösningar. Ett område i stort behov av innovation är flygindustrin som länge varit en av de största klimatbovarna. Flygindustrin stora problem är att dess fordon både har begränsad volym och vikt. I detta kandidatexamensarbete kommer vi diskutera en hybridlösning där obemannade drönare drivs av en hybridlösning där batterier tillsammans med bränsleceller driver drönaren. Batterierna och bränslecellerna komplimenterar varandra då bränslecellerna är är lättviktiga och tillför en stabil produktion av ström till drönaren medan batterierna agerar komplement och hjälper till när det behövs extra kraft. Projektet som i samarbete med The Green Raven project utfördes för att utvärdera det optimala systemet för att förse drönaren nog med kraft i en timme. Projektet har utförts teoretiskt i Matlab och Simulink för att hitta den optimala balansen mellan batterier och bränsleceller. Från dessa simuleringar samlades data in för att optimera konfigurationen mellan bränslecellerna och batterierna. Från resultaten drogs slutsatsen att 2 batterier med en kapacitet på 4000 mAh som tillsammans med vätgas som förvarades i en 2 liter tank med ett tryck på 300 bar var den bästa konfigurationen. Denna lösning ansågs som den bästa då all vätgas förbrukades under simulation och att batteriet vid stopp hade en lägre laddning än vid flygstart.
3

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.

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