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Analysis of a Clean Energy Hub Interfaced with a Fleet of Plug-in Fuel Cell VehiclesSyed, Faraz January 2011 (has links)
The ‘hydrogen economy’ represents an energy system in which hydrogen and electricity are the dominant energy carriers for use in transportation applications. The ‘hydrogen economy’ minimizes the use of fossil fuels in order to lower the environmental impact of energy use associated with urban air pollution and climate change. An integrated energy system is required to deal with diverse and distributed energy generation technologies such a wind and solar which require energy storage to level energy availability and demand. A distributed ‘energy hub’ is considered a viable concept in envisioning the structure of an integrated energy system. An energy hub is a system which consists of energy input/output, conversion and storage technologies for multiple energy carriers, and would provide an interface between energy producers, consumers, and the transportation infrastructure. Considered in a decentralized network, these hubs would form the nodes of an integrated energy system or network.
In this work, a model of a clean energy hub comprising of wind turbines, electrolyzers, hydrogen storage, a commercial building, and a fleet of plug-in fuel cell vehicles (PFCVs) was developed in MATLAB, with electricity and hydrogen used as the energy carriers. This model represents a hypothetical commercial facility which is powered by a renewable energy source and utilizes a zero-emissions fleet of light duty vehicles. The models developed herein capture the energy and cost interactions between the various energy components, and also calculate the CO2 emissions avoided through the implementation of hydrogen economy principles. Wherever possible, similar models were used to inform the development of the clean energy hub model. The purpose of the modelling was to investigate the interactions between a single energy hub and novel components such as a plug-in fuel cell vehicle fleet (PFCV). The final model reports four key results: price of hub electricity, price of hub hydrogen, total annual costs and CO2 emissions avoided. Three scenarios were analysed: minimizing price of hub electricity, minimizing total annual costs, and maximizing the CO2 emissions avoided.
Since the clean energy hub could feasibly represent both a facility located within an urban area as well as a remote facility, two separate analyses were also conducted: an on-grid analysis (if the energy hub is close to transmission lines), and an off-grid analysis (representing the remote scenarios).
The connection of the energy hub to the broader electricity grid was the most significant factor affecting the results collected. Grid electricity was found to be generally cheaper than electricity produced by wind turbines, and scenarios for minimizing costs heavily favoured the use grid electricity. However, wind turbines were found to avoid CO2 emissions over the use of grid electricity, and scenarios for maximizing emissions avoided heavily favoured wind turbine electricity. In one case, removing the grid connection resulted in the price of electricity from the energy hub increasing from $82/MWh to $300/MWh.
The mean travel distance of the fleet was another important factor affecting the cost modelling of the energy hub. The hub’s performance was simulated over a range of mean travel distances (20km to 100km), and the results varied greatly within the range. This is because the mean travel distance directly affects the quantities of electricity and hydrogen consumed by the fleet, a large consumer of energy within the hub. Other factors, such as the output of the wind turbines, or the consumption of the commercial building, are largely fixed. A key sensitivity was discovered within this range; the results were ‘better’ (lower costs and higher emissions avoided) when the mean travel distance exceeded the electric travel range of the fleet. This effect was more noticeable in the on-grid analysis. This sensitivity is due to the underutilization of the hydrogen systems within the hub at lower mean travel distances. It was found that the greater the mean travel distance, the greater the utilization of the electrolyzers and storage tanks lowering the associated per km capital cost of these components. At lower mean travel distances the utilization of the electrolyzers ranged from 25% to 30%, whereas at higher mean travel distances it ranged from 97% to 99%. At higher utilization factors the price of hydrogen is reduced, since the cost recovery is spread over a larger quantity of hydrogen.
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Analysis of a Clean Energy Hub Interfaced with a Fleet of Plug-in Fuel Cell VehiclesSyed, Faraz January 2011 (has links)
The ‘hydrogen economy’ represents an energy system in which hydrogen and electricity are the dominant energy carriers for use in transportation applications. The ‘hydrogen economy’ minimizes the use of fossil fuels in order to lower the environmental impact of energy use associated with urban air pollution and climate change. An integrated energy system is required to deal with diverse and distributed energy generation technologies such a wind and solar which require energy storage to level energy availability and demand. A distributed ‘energy hub’ is considered a viable concept in envisioning the structure of an integrated energy system. An energy hub is a system which consists of energy input/output, conversion and storage technologies for multiple energy carriers, and would provide an interface between energy producers, consumers, and the transportation infrastructure. Considered in a decentralized network, these hubs would form the nodes of an integrated energy system or network.
In this work, a model of a clean energy hub comprising of wind turbines, electrolyzers, hydrogen storage, a commercial building, and a fleet of plug-in fuel cell vehicles (PFCVs) was developed in MATLAB, with electricity and hydrogen used as the energy carriers. This model represents a hypothetical commercial facility which is powered by a renewable energy source and utilizes a zero-emissions fleet of light duty vehicles. The models developed herein capture the energy and cost interactions between the various energy components, and also calculate the CO2 emissions avoided through the implementation of hydrogen economy principles. Wherever possible, similar models were used to inform the development of the clean energy hub model. The purpose of the modelling was to investigate the interactions between a single energy hub and novel components such as a plug-in fuel cell vehicle fleet (PFCV). The final model reports four key results: price of hub electricity, price of hub hydrogen, total annual costs and CO2 emissions avoided. Three scenarios were analysed: minimizing price of hub electricity, minimizing total annual costs, and maximizing the CO2 emissions avoided.
Since the clean energy hub could feasibly represent both a facility located within an urban area as well as a remote facility, two separate analyses were also conducted: an on-grid analysis (if the energy hub is close to transmission lines), and an off-grid analysis (representing the remote scenarios).
The connection of the energy hub to the broader electricity grid was the most significant factor affecting the results collected. Grid electricity was found to be generally cheaper than electricity produced by wind turbines, and scenarios for minimizing costs heavily favoured the use grid electricity. However, wind turbines were found to avoid CO2 emissions over the use of grid electricity, and scenarios for maximizing emissions avoided heavily favoured wind turbine electricity. In one case, removing the grid connection resulted in the price of electricity from the energy hub increasing from $82/MWh to $300/MWh.
The mean travel distance of the fleet was another important factor affecting the cost modelling of the energy hub. The hub’s performance was simulated over a range of mean travel distances (20km to 100km), and the results varied greatly within the range. This is because the mean travel distance directly affects the quantities of electricity and hydrogen consumed by the fleet, a large consumer of energy within the hub. Other factors, such as the output of the wind turbines, or the consumption of the commercial building, are largely fixed. A key sensitivity was discovered within this range; the results were ‘better’ (lower costs and higher emissions avoided) when the mean travel distance exceeded the electric travel range of the fleet. This effect was more noticeable in the on-grid analysis. This sensitivity is due to the underutilization of the hydrogen systems within the hub at lower mean travel distances. It was found that the greater the mean travel distance, the greater the utilization of the electrolyzers and storage tanks lowering the associated per km capital cost of these components. At lower mean travel distances the utilization of the electrolyzers ranged from 25% to 30%, whereas at higher mean travel distances it ranged from 97% to 99%. At higher utilization factors the price of hydrogen is reduced, since the cost recovery is spread over a larger quantity of hydrogen.
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Optimization of a charging system for electric vehicles : A case study in Magangué, Colombia / Optimering av laddningssystem för Fordon/elbåtar : En fallstudie för Magangué, ColombiaLönnqvist, Malin January 2020 (has links)
To reduce the emissions from the transport sector, the electric vehicle (EV) is a promising alternative to the internal combustion engine vehicle (ICEV). An important aspect of implementing new transport systems in terms of EVs is the charging strategy, as many energy sources with different limitations can be utilized. Although various studies have investigated charging strategies for electric cars, there is a lack of optimized charging strategies for electric boats with specific considerations for these cases. In Colombia, the river transport sector plays an important role in areas with lack of access to other transport alternatives. This study presents an optimization of the charging strategy for an electric boat that is planned to traffic the Magdalena River in the region of Magangué, Colombia. The objective of the optimization model is to minimize the electricity bill while maintaining a desired transport service. The study considers solar photovoltaics (PV), the electric grid and battery storage for charging, and compares different battery sizes in a scenario analysis. Furthermore, the impact of the instability of the grid is included in terms of a sensitivity analysis of grid blackouts, together with varying battery investment costs. The results show that PV is a recommended investment as it lowers the charging cost and gives positive results in terms of economic feasibility. To further increase the economic feasibility, lower the charging costs and improve the reliability of the system, it is suggested to invest in energy storage. The techno-economic feasibility of storage is heavily affected by battery investment costs and number of grid blackouts affecting the boat charging. If the investment cost is low and the number of blackouts is high, a large storage is a suggested solution. / För att minska utsläppen från transportsektorn är elfordon (EV) ett lovande alternativ till förbränningsmotorfordon (ICEV). En viktig aspekt vid implementering av nya transportsystem för EV:s är val av laddningsstrategi, eftersom många energikällor med olika begränsningar kan användas. Även om flertalet studier har undersökt laddningsstrategier för elbilar, saknas optimerade laddningsstrategier för elbåtar och som beaktar de specifika förhållandena för dessa fall. I Colombia spelar flodtransportsektorn en viktig roll i områden med brist på tillgång till andra transportalternativ. Denna studie presenterar en optimering av laddningsstrategin för en elbåt som är planerad att trafikera floden Magdalena i regionen Magangué, Colombia. Syftet med optimeringsmodellen är att minimera elräkningen samtidigt som en önskad transporttjänst bibehålls. Studien omfattar solceller (PV), elnätet och batterilagring för laddning, och jämför olika batteristorlekar i en scenarioanalys. Vidare inkluderas effekterna av elnätets instabilitet genom en känslighetsanalys av strömavbrott, tillsammans med varierande kostnader för batteriinvesteringar. Resultaten visar att PV är en rekommenderad investering eftersom den sänker laddningskostnaden och ger positiva resultat när det gäller ekonomisk lönsamhet. För att ytterligare öka den ekonomiska lönsamheten, sänka laddningskostnaderna och förbättra systemets tillförlitlighet föreslås det att investera i energilagring. Den teknisk-ekonomiska genomförbarheten för lagring påverkas starkt av kostnader för batteriinvesteringar och antalet strömavbrott som påverkar båtladdningen. Om investeringskostnaden är låg och antalet strömavbrott är högt är energilagring med stor kapacitet en föreslagen lösning.
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Transportörer och transportköpares väg mot fullständig elektrifiering av tunga transporter : En fallstudie kring implementering och uppskalning / Carriers’ and transport buyers’ path towards complete electrification of heavy transports’ : A case study about implementation and scaling upJaktfalk, Linnéa, Arvidsson, Julia January 2024 (has links)
Transporter står idag för en stor andel av Sveriges koldioxidutsläpp. Det gör att logistikfrågor blir extra viktiga då vidareutveckling och omformning av logistiksystem kan göra stor skillnad. Elektrifiering av fordon är en framtida lösning på problemet. Däremot anses det fortfarande vara ett förhållandevis nytt och osäkert område och det finns idag få exempel på implementering av elektrifierade fordon. Transportören Renall och transportköparen Returpack är två framstående företag med starkt hållbarhetsfokus som agerar fallföretag för studien. De har högt uppsatta mål, däribland elektrifiering av en stor andel av sina fordonsflottor till 2030. Studiens syfte är därför formulerat som följande: Syftet är att utreda hur transportörer och transportköpare kan arbeta mot fullständig elektrifiering av tunga transporter. Studien är uppdelad i tre primära delar. Den första delen utvecklar en metodik för hur elektrifierade fordon ska implementeras i verksamheter för att sedan kunna skalas upp. Denna metodik har resulterat i tre primära delar. Den första delen är utformning av ett elektrifierat logistiksystem där större strukturförändringar i logistiksystemet måste göras med syfte att öka effektivitet, nyttjandegrad och förutsägbarhet. Den andra delen är utformning av fordonsflotta där beslut om lämpliga batterikapaciteter för varje enskilt fordon tas. Den tredje delen utformning av laddstrategi beslutar om lämplig laddstrategi utifrån fordons- och uppdragskarakteristik. Den utformade metodiken appliceras sedan på fallföretagens presenterade empiri för att resultera i rekommendationer för hur de bör utforma sina elektrifierade logistiksystem, fordonsflottor samt laddstrategier. Efter analys av lösningar som ämnar anpassa logistiksystemet till elektrifiering presenteras rekommendationer för fallföretagen utifrån deras specifika situationer. Det kan dock konstateras att en stark maktposition, ett välutvecklat systemstöd samt kompetens inom elektrifiering underlättar arbetet mot ett elektrifierat logistiksystem. Vid utformning av fordonsflottan presenteras det samlade resultatet av ekonomiska analyser samt bedömningar av genomförbarheten för respektive fordon. Resultatet påvisar att det för cirka hälften av fordonen är ekonomiskt fördelaktigt med ett mindre batteri men att detta oftast begränsas av brist på laddinfrastruktur och behov av flexibilitet vilket innebär behov av överdimensionering. Det samlade resultatet innebär att cirka 20% av fordonsflottan rekommenderas mindre batterier. Vid utveckling av laddstrategier är rekommendationerna liknande för fallföretagen vilket beror på att en laddstrategi är beroende av enskilda fordons karakteristik snarare än en aktörs roll. Fallföretagen rekommenderas att utveckla två primära laddstrategier: en return to base strategi för laddning mellan skift samt en on route strategi för laddning under pågående rutt. Därtill utvecklas även en kostnadsmodell för att kunna genomföra en kostnadsanalys av hur kostnader förändras vid byte från nuvarande bränsle till elektrifierad drivlina. Den visar att sänkning eller höjning av kostnader vid byte av drivlina varierar mellan olika fordonstyper och områden, men att lönsamhet kan uppnås i många fall. Däremot krävs ibland justeringar och förändringar av logistiksystemet. Främst ses att långa avtalsperioder och hög nyttjandegrad av fordonen är att föredra. Likaså ger minskade inköpspriser stort utslag på resultatet. / Transport related activities currently account for a significant portion of Sweden’s carbon dioxide emissions. This makes logistics issues particularly important, as further development and transformation of logistics systems can make a big difference. Electrification of heavy trucks is a future solution to the problem. However, it is still considered a relatively new and uncertain area, and there are currently few examples of the implementation of electrified heavy trucks. The carrier Renall and the transport buyer Returpack are two prominent companies with a strong sustainability focus, acting as case companies for the study. They have currently set ambitious goals, including electrifying a large portion of their heavy truck fleets by the year 2030. Therefore, the purpose of the study is formulated as follows: The purpose is to investigate how carriers’ and transport buyers’ can work towards complete electrification of heavy transports. The study is divided into three primary parts. The first part develops a methodology for implementing electrified heavy trucks in operations, with the goal of scalability. This methodology has resulted in three sub-parts. The first sub-part is the design of an electrified logistics system, where significant structural changes in the logistics system are necessary to increase efficiency, utilization, and predictability. The second sub-part involves designing the heavy truck fleet, including decisions on appropriate battery capacities for each individual heavy truck. The third sub-part focuses on designing a charging strategy based on truck and mission characteristics. The formulated methodology is then applied to the empirical data presented by the case companies, resulting in recommendations on how they should design their electrified logistics systems, heavy truck fleets, and charging strategies. Solutions aimed at adapting the logistics system to electrification are analyzed, which result in recommendations for the case companies based on their specific situations. However, it can be noted that a strong market position, well-developed system support, and knowledge in electrification can ease the transition to an electrified logistics system.In the design of the heavy truck fleet, the combined results of economic analyses and feasibility assessments for each vehicle are presented. The results indicate that for approximately half of the vehicles, it is economically advantageous to have a smaller battery. However, this is often limited by a lack of charging infrastructure and the need for flexibility, which necessitate overdimensioning. The combined result is that approximately 20% of the vehicle fleet is recommended to have smaller batteries.In the development of charging strategies, the recommendations are similar for the case companies, as a charging strategy depends on the characteristics of individual vehicles rather than the role of the operator. The case companies are recommended to develop two primary charging strategies: a return to base strategy for charging between shifts and an on route strategy for charging during the ongoing route. Lastly, a cost model is developed to conduct a cost analysis of how expenses change when transitioning from heavy trucks fueled by HVO or biogas to electrified heavy trucks. It shows that cost reduction or cost increase upon fuel conversion varies among different truck types and regions, but profitability can be achieved in many cases. However, adjustments and changes to the logistics system are sometimes necessary. Long contract periods and high vehicle utilization are particularly favorable. Similarly, reduced purchase prices have a significant impact on the outcome.
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