Les objectifs récents en ce qui concerne la durabilité des systèmes électriques et l'atténuation des menaces liées au changement climatique modifient la portée des exigences de planification de ces systèmes. D'une part, les systèmes durables d'énergie à faible émission de carbone qui comportent une part élevée de sources d'énergie renouvelables intermittentes(IRES) se caractérisent par une forte augmentation de la variabilité intertemporelle et nécessitent des systèmes flexibles capables d'assurer la sécurité de l'approvisionnement électrique. D'autre part, la fréquence et la gravité accrues des phénomènes climatiques extrêmes menacent la fiabilité du fonctionnement des réseaux électriques et exigent des systèmes résilients capables de résister à ces impacts potentiels. Tout en s'assurant que les incertitudes inhérentes au système sont bien prises en compte directement au moment de la prise des décisions de planification à long terme. Dans ce contexte, la présente thèse vise à développer une modélisation technicoéconomique et un cadre d'optimisation robuste pour la planification des systèmes électriques multi-périodes en considérant une part élevée d'IRES et la résilience aux phénomènes climatiques extrêmes. Le problème spécifique de planification considéré est celui du choix de la technologie, de la taille et du programme de mise en service des unités de production conventionnelles et renouvelables sous des contraintes techniques, économiques,environnementales et opérationnelles. Dans le cadre de ce problème, les principales questions de recherche à aborder sont : (i) l'intégration et l'évaluation appropriées des besoins de flexibilité opérationnelle en raison de la variabilité accrue des parts élevées de la production d'IRES, (ii) la modélisation et l'intégration appropriées des exigences de résilience contre les phénomènes climatiques extrêmes dans la planification du système électrique et (iii) le traitement des incertitudes inhérentes de l'offre et la demande dans ce cadre de planification. En résumé, les contributions originales de cette thèse sont :- Proposer un modèle de planification du système électrique intégré multi période avec des contraintes dynamiques et en considérant un pourcentage élevé de pénétration des énergies renouvelables.- Introduire la mesure du déficit de flexibilité prévu pour l'évaluation de la flexibilité opérationnelle.- Proposer un ensemble de modèles linéaires pour quantifier l'impact des vagues de chaleur extrêmes et de la disponibilité de l'eau sur le déclassement des unités de production d'énergie thermique et nucléaire, la production d'énergie renouvelable et la consommation électrique du système.- Présenter une méthode permettant d'intégrer explicitement l'impact des phénomènes climatiques extrêmes dans le modèle de planification du système électrique.- Traiter les incertitudes inhérentes aux paramètres de planification du système électrique par la mise en oeuvre d'un nouveau modèle d'optimisation adaptatif robuste à plusieurs phases.- Proposer une nouvelle méthode de solution basée sur l'approximation des règles de décision linéaires du modèle de planification robuste.- Appliquer le cadre proposé à des études de cas de taille pratique basées sur des projections climatiques réalistes et selon plusieurs scénarios de niveaux de pénétration des énergies renouvelables et de limites de carbone pour valider la pertinence de la modélisation globale pour des applications réelles. / Recent objectives for power systems sustainability and mitigation of climate change threats are modifying the breadth of power systems planning requirements. On one hand, sustainable low carbon power systems which have a high share of intermittent renewable energy sources (IRES) are characterized by a sharp increase in inter-temporal variability and require flexible systems able to cope and ensure the security of electricity supply. On the other hand, the increased frequency and severity of extreme weather events threatens the reliability of power systems operation and require resilient systems able to withstand those potential impacts. All of which while ensuring that the inherent system uncertainties are adequately accounted for directly at the issuance of the long-term planning decisions. In this context, the present thesis aims at developing a techno-economic modeling and robust optimization framework for multi-period power systems planning considering a high share of IRES and resilience against extreme weather events. The specific planning problem considered is that of selecting the technology choice, size and commissioning schedule of conventional and renewable generation units under technical, economic, environmental and operational constraints. Within this problem, key research questions to be addressed are: (i) the proper integration and assessment of the operational flexibility needs due to the increased variability of the high shares of IRES production, (ii) the appropriate modeling and incorporation of the resilience requirements against extreme weather events within the power system planning problem and (iii) the representation and treatment of the inherent uncertainties in the system supply and demand within this planning context. In summary, the original contributions of this thesis are: - Proposing a computationally efficient multiperiod integrated generation expansion planning and unit commitment model that accounts for key short-term constraints and chronological system representation to derive the planning decisions under a high share of renewable energy penetration. - Introducing the expected flexibility shortfall metric for operational flexibility assessment. - Proposing a set of piece-wise linear models to quantify the impact of extreme heat waves and water availability on the derating of thermal and nuclear power generation units, renewable generation production and system load. - Presenting a method for explicitly incorporating the impact of the extreme weather events in a modified power system planning model. - Treating the inherent uncertainties in the electric power system planning parameters via a novel implementation of a multi-stage adaptive robust optimization model. - Proposing a novel solution method based on ``information basis'' approximation for the linear decision rules of the affinely adjustable robust planning model. - Applying the framework proposed to a practical size case studies based on realistic climate projections and under several scenarios of renewable penetration levels and carbon limits to validate the relevance of the overall modeling for real applications.

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Strategies to harness the energy from organic waste is gaining importance on a global scale, especially in countries with large quantities of it. In this paper, a techno-economic analysisand a field study were performed to investigate the feasibility of five scenarios for a conceptual biogas facility, based on a case study from Colombia. The plant designs involved anaerobic digestion followed by different combinations of biogas upgrading, combined heat and power and/or steam methane reforming technologies and investigated four different feedstocks. The results demonstrated that the road infrastructure leading to the current proposed site is inadequate, and a new location should be found. Anaerobic digestion alone was most profitable with the shortest payback period. Organic Municipal Solid Waste and Poultry Manure produced high techno-economic potential depending on the scenario. The production of hydrogen using anaerobic digestion, steam methane reforming and combined heat and power with or without upgrading is not recommended due to the current market prices and high heat consumption. However, it can be profitable to implement green energy initiatives as a strategy to establish and lead future energy markets.

Background According to the United Nations, climate change is one of the most challenging and urgent problems. To reduce emissions, various regulations have been introduced. Emissions trading (EU-ETS) and carbon dioxide tax are two economic instruments aimed at reducing greenhouse gas emissions. The industrial sector in Sweden today accounts for 31% of carbon dioxide emissions, and a common fossil energy carrier used is liquified petroleum gas (LPG). When LPG is burned, carbon dioxide is produced, contributing to climate change. By replacing LPG with a sustainable energy carrier, industries can reduce costs associated with emissions and thus increase competitiveness while lowering environmental impact. Therefore, there is a need for a framework that deals with both the economic and environmental impact that arises if alternative sustainable energy carriers replace LPG. Objectives The study’s objective is to evaluate alternative energy carriers that can phase out the use of LPG. The contribution of this study is a framework that analyzes and visualizes the economic and sustainable benefits of changing energy carriers. Methods A techno-economic model was developed by evaluating economic and sustainable indicators. A case study was conducted on a company that uses LPG in its manufacturing process. Eight different scenarios were set up where various energy carriers are used. Data concerning the different scenarios were collected. The scenarios were compared and analyzed based on the model to see which alternative energy carriers generate economic and sustainable improvements. Results The results from the case study show that all scenarios had an increased environmental performance compared to LPG. Either by reduced CO2 emissions or by being carbon dioxide neutral. From an economic perspective, only one scenario is more favorable than LPG, Bio- LPG. Bio-LPG reduces the total cost by 28.5%. Conclusions The study presents a model that can evaluate alternative energy carriers from an economic and environmental perspective. In many cases, a trade-off was discovered either being sustainable at a high cost or paying fees for emissions at a lower price. Alternative energy carriers exist with less environmental impact. Still, the technology for many of them is not sufficiently developed for large-scale production and use, which means that the cost is too high. Depending on the company's business strategy, the model can visualize the effects of a possible change of energy carrier. / Bakgrund Klimatförändringarna är ett av de mest utmanande och brådskande problemen enligt Förenta nationerna, för att minska utsläppen har olika regleringar införts. Handel med utsläppsrättigheter (EU-ETS) och koldioxidskatt är två ekonomiska styrmedel med syfte att minska växthusgasutsläppen. Industrisektorn i Sverige står idag för 31% av koldioxidutsläppen och en vanlig fossil energibärare som används är gasol. När gasol förbrännas produceras koldioxid som bidrar till klimatförändringar. Genom att byta ut gasol mot en hållbar energibärare kan industrier minska kostnader som är förknippade med utsläpp och på sådant vis öka konkurrenskraft, samtidigt som man minskar miljöpåverkan. Det finns därav ett behov av ett ramverk som behandlar både den ekonomisk och miljömässig påverkan som uppkommer om gasol byts ut mot alternativa hållbara energibärare. Syfte Syftet med studien är att utvärdera alternativa energibärare som kan fasa ut användandet utav gasol. Bidraget från denna studie är ett ramverk som analyserar och visualiserar de ekonomiska och hållbara fördelarna med att byta energibärare. Metod En tekno-ekonomisk modell utvecklades genom att utvärdera ekonomiska och hållbara indikatorer. En fallstudie utfördes på ett företag som använder gasol i sin tillverkningsprocess. Åtta olika scenarier sattes upp där olika energibärare används. Data rörande de olika scenarierna samlades in. Scenarierna jämfördes och analyserades utifrån modellen för att se vilka alternativa energibärare som genererar ekonomiska och hållbara förbättringar. Resultat Resultaten från fallstudien visar att alla scenarier hade en ökad miljöprestanda jämfört med gasol. Antingen genom minskade CO2-utsläpp eller genom att vara koldioxidneutrala. Ur ett ekonomiskt perspektiv är endast ett scenario mer gynnsamt än gasol, biogasol. Biogasol minskar den totala kostnaden med 28.5 %. Slutsatser Studien presenterar en modell som kan användas för att utvärdera alternativa energibärare utifrån ett ekonomiskt och hållbart perspektiv. En avvägning upptäcktes i många fall, antingen vara hållbar till hög kostnad eller betala avgifter för utsläpp till en lägre kostnad. Alternativa energibärare existerar som har mindre miljöpåverkan, men teknologin för många utav dem är ej tillräckligt utvecklad för storskalig produktion och användning vilket medför att kostanden är för hög. Beroende på vilken affärsstrategi företag har kan modellen visualisera effekterna vid ett eventuellt byte av energibärare.

Decarbonization of the marine transportation sector is contributing to the growth of electric recreational boats. The growth of electric recreational boats also means an increase in charging demand to meet the power needs of electric boats to address the problem of range anxiety. To meet the charging demand of electric boat owners, electrification of existing public boat marinas is necessary. The objective of this study is to determine the optimal number of fast and slow chargers to meet charging demand of electric boats at public boat marinas. This study proposes a mathematical model formulated using mixed integer linear optimization programming (MILP). The model is validated using 9 public marinas owned by the city of Stockholm; the technical and economic data of one of the existing electric boats in the Swedish market, electric chargers; and hourly availability profile of boats at the marinas considered. The economic analysis was carried out to determine the year each station will break-even financially. The result obtained is the number of slow chargers and fast chargers to meet the charging demand of all electric boats; and the power drawn per charger type per station. Due to availability profile and charging demand of the boats, the model optimized for higher number of fast chargers compared to slow chargers at some of the stations; and at some of the stations, higher number of slow chargers compared to fast chargers; and equal number of slow and fast chargers at some of the stations. Also, maximum power is drawn between 01:00 and 03:00 at midnight and between 13:00 and 15:00 during the day, and this was as a result of the lowest average electricity price within this time period. In addition, the economic analysis shows that all the stations are financially viable and break-even within the first seven years of their lifetime. The result obtained shows that the number of electric chargers (slow and fast) generated by the model meet the charging demands of all the boats at each of the stations optimally. / Avkarbonisering av sjötransportsektorn bidrar till tillväxten av elektriska fritidsbåtar. Tillväxten av elektriska fritidsbåtar innebär också en ökning av laddningsefterfrågan för att möta elbåtarnas kraftbehov för att lösa problemet med räckviddsångest. För att möta laddbehovet från elbåtsägare är elektrifiering av befintliga offentliga båthamnar nödvändig. Syftet med denna studie är att fastställa det optimala antalet snabba och långsamma laddare för att möta laddningsbehovet för elbåtar vid offentliga båthamnar. Denna studie föreslår en matematisk modell formulerad med hjälp av blandad heltals linjär optimeringsprogrammering (MILP). Modellen är validerad med 9 offentliga småbåtshamnar som ägs av Stockholms stad; tekniska och ekonomiska data för en av de befintliga elbåtarna på den svenska marknaden, elektriska laddare; och timvis tillgänglighetsprofil för båtar vid de övervägda marinorna. Den ekonomiska analysen genomfördes för att fastställa vilket år varje station kommer att nå ekonomiskt nollresultat. Resultatet som erhålls är antalet långsamma laddare och snabbladdare för att möta laddningsbehovet för alla elektriska båtar; och ström som dras per laddartyp per station. På grund av båtarnas tillgänglighetsprofil och laddningsbehov, optimerade modellen för fler snabbladdare jämfört med långsamma laddare på några av stationerna; och på några av stationerna, högre antal långsamma laddare jämfört med snabbladdare; och lika många långsamma och snabba laddare på några av stationerna. Dessutom dras maximal effekt mellan 01:00 och 03:00 vid midnatt och mellan 13:00 och 15:00 under dagen, och detta var ett resultat av det lägsta genomsnittliga elpriset inom denna tidsperiod. Dessutom visar den ekonomiska analysen att alla stationer är ekonomiskt bärkraftiga och nollresultat inom de första sju åren av sin livstid. Resultatet som erhållits visar att antalet elektriska laddare (långsamma och snabba) som genereras av modellen uppfyller laddningskraven för alla båtar vid var och en av stationerna.

To meet the energy targets and improve the lack of power and higher prices in southern Sweden, the amount of electricity must increase, and alternative fuel sources be introduced. This thesis examines the techno-economic feasibility of offshore wind-hydrogen production in southern Sweden, depending on whether an onshore- or offshore hydrogen system is used, and how grid connection subsidies would affect this. New research and development regarding the subjects were analyzed and reviewed. A project that has currently applied for a permit in southern Sweden, Skåne Offshore Wind Park, was used as a case study where the information from the review and data from similar parks were used to determine the cost and production for the two different systems. The costs were then adjusted according to the three different subsidy scenarios: current with no subsidies, partial with sea cable and transformer costs removed, or a full subsidy scenario where only the internal grid cost remained to achieve feasible levelized costs for electricity and hydrogen based on a discount rate of 6% and a lifetime of 25 years. Finally, a sensitivity analysis was performed.   The results showed that market competitive electricity prices are only achieved with an onshore hydrogen system- and only if a full subsidy is introduced or if a best-case scenario is applied. In a worst-case scenario, no competitive electricity prices were achieved. For the offshore hydrogen system, the extra fuel system is too inefficient for electricity production. For hydrogen, prices were achieved within a reasonable price range of green hydrogen for all scenarios, where the onshore hydrogen system was 4% more advantageous. In a best-case scenario, competitive values ​​even against blue hydrogen were achieved for the offshore hydrogen systems and for the full subsidy onshore hydrogen system. For hydrogen, the offshore hydrogen system's hydrogen prices were competitive regardless of subsidies, however this system had the highest CAPEX and OPEX costs.   The results of the study underline the need for fixed conditions but also the necessity of introducing a full subsidy for the grid connection cost - or best-case scenario conditions - to encourage further offshore wind power development.

Increasing resource efficiency by utilising secondary raw material is one of the key characteristics of a circular economy. Textile dust fibre, a waste generated from textile mechanical recycling has the prospect to be utilised as secondary raw material for producing novel material: textile paper suitable for packaging and other applications. A comparative Life Cycle Assessment (LCA) of carrier bags made from one ton of virgin paper, recycled paper and novel textile paper (~22584paper bags with grammage of 100 g/m2 and same dimensions for all 3 types of bags) showed that textile paper bag is more environmentally friendly in terms of carbon footprint. The largest environmental contributors were energy consumed in the pulping and paper making processes, followed by the use of adhesives and printing ink in the conversion process of paper to papercarrier bags. A comparative Techno-economic Assessment (TEA) was carried out for the operating cost of producing the three selected carrier bag types. The analysis conveyed that textile paper bags are more economically attractive, mainly due to the partial substitution of paper fibre with low-cost textile dust fibre. Furthermore, a simple tool was developed with an attempt to assess and compare materials suitability for the circular economy considering life cycle thinking and business perspectives. Assessment of textile paper using the Circular material assessment tool indicated that there is still scope for improvement on the following circularity characteristics of circular material: scarcity of raw material, local supply of resources, clean and non-toxic resources. Textile paper material scored high in the following circularity characteristics: secondary raw material, industrial symbiosis, recycling, resource efficiency in manufacturing and use. In the final step, the textile paper bag was eco-designed through the combined and iterative LCA and TEA approach with the aim to achieve improved scores as a circular material. In order to understand the overall sustainability advantages and trade-offs, further research is recommended on different textile dust fibre grades as well as textile paper performance based on mechanical properties. It is also recommended to investigate textile paper in other applications like one time fashion clothes, reusable paper bags as textile hangers etc.

This thesis presents the potential of biogas production using food waste collected from the region of Kartamantul in Yogyakarta, Indonesia. Biogas can be used for cooking and generating electricity. The study compares two different end uses or markets for utilizing the biogas in the region. The daily food waste collected in the region of Kartamantul is 120 tonnes. This corresponds to a daily biogas production of 13 087 m3. Electricity generated from biogas can replace fossil-based coal electricity while cooking biogas can substitute the common fossil fuel liquefied Petroleum Gas (LPG). The price for selling one kWh of electricity to the state owned enterprise PLN is 16.5 USD cents. The price for selling one m3 of biogas for cooking is 38.5 USD cents, which is equivalent to the available price of LPG. The study finds that the avoided emission due to the substitution of fossil-based coal electricity and cooking LPG-gas is around 64 GgCO2-eq per year. Considering the economical results for a life span of 20 years in the first utilization option Biogas for Electricity gives a net present value (NPV) of 2 MUSD while for the utilization option Biogas for Cooking gives a net present value (NPV) of 5.82 MUSD. The breakeven for Biogas for Electricity is 13.8 USD cents per kWhe while for Biogas for Cooking is 25.5 USD cents per m3-biogas. The study concludes that it is feasible to invest in AD plant in the region of Kartamantul where both markets are profitable and environmentally friendly. / Denna avhandling visar potentialen för biogasproduktion med hjälp av matavfall som samlats från regionen Kartamantul i Yogyakarta, Indonesien. Biogas kan användas för matlagning och elproduktion. Studien jämför två olika slutanvändningar eller marknader för att utnyttja biogasen i regionen. Det dagliga matavfallet som samlas i regionen Kartamantul är 120 ton. Detta motsvarar en daglig biogasproduktion på 13 087 m3. Elektricitet som genereras från biogas kan ersätta fossilbaserad koldioxid, medan tillagning av biogas kan ersätta det gemensamma fossila bränslet flytande petroleumgas (LPG). Priset för att sälja en kWh el till det statligt ägda företaget PLN är 16,5 USD cent. Priset för att sälja en m3 biogas för matlagning är 38,5 USD cent, vilket motsvarar det tillgängliga priset på LPG. Studien konstaterar att den undvikna utsläppet på grund av substitutionen av fossilbaserad kolkraft och matlagning av gasol är cirka 64 GgCO2-ekv per år. Med tanke på de ekonomiska resultaten för en livslängd på 20 år i det första utnyttjandegradet ger Biogas for Electricity ett nettopåverkande värde (NPV) på 2 MUSD medan för utnyttjandegraden Biogas for Cooking ger ett nettoförskott (NPV) på 5,82 MUSD. Breakeven för biogas för el är 13,8 USD cent per kWhe medan för Biogas for Cooking är 25,5 USD cent per m3-biogas. Studien drar slutsatsen att det är möjligt att investera i AD-anläggningar i regionen Kartamantul där båda marknaderna är lönsamma och miljövänliga.

Norway has already an almost emission-free power production and its sales of zero-emission light-duty vehicles surpassed 30% in 2018; a natural next challenge is to identify ways to reduce emissions of heavyduty vehicles. In this work the possibilities to deploy Fuel Cell Electric Trucks (FCET) on the route Oslo-Trondheim are analyzed by doing a techno-economic analysis. The literature study identified that in average 932 kton goods where transported between the cities. The preferred road choice goes through Østerdalen and that an average load for a long-distance truck is 16 tons. The methodology used in the study is based on cost curves for both truck and infrastructure, and a case study with various scenarios is evaluated to find a profitable business case for both an FCET fleet and its infrastructure. The cost curves for trucks are based on total cost of ownership (TCO) as a function of hydrogen price, while the levelized cost of hydrogen (LCOH) is used to present the cost of infrastructure. An analysis was made to identify the trucks component sizes and a FCET for this route would require an onboard hydrogen storage of 46 kg, a fuel cell stack with a nominal power of 200 kW, a battery of 100 kWh (min SOC 22%), and an electric motor with a rated power of 402 kW. TCO was calculated both for an FCET based on the dimensioned components and a biodiesel truck. The results show that an FCET purchased in 2020 can be competitive with biodiesel with a hydrogen price of 38.6 NOK/kgH2. While the hydrogen price can increase to 71.8 NOK/ kgH2 if the FCET is purchased in 2030. To identify the most suitable infrastructure, four different designs of hydrogen refueling stations (HRS) were compared. Furthermore, hydrogen production units (HPUs) with both alkaline or PEM type water electrolyzer were compared. The analysis in this study showed that the most cost competitive option was a 350-bar HRS without cooling, which only can serve type III onboard storage tanks. A HPU with alkaline electrolyzer was the most price competitive alternative. In case each HRS is refueling more than 7 FCETs per day, an HPU in direct connection to HRS is the preferred infrastructure setup. Three HRS are required along the route to ensure a minimum service level for the FCETs. When the TCO of the fuel cell truck and LCOH of the hydrogen infrastructure were compared for a 2020 scenario, no feasible solution was identified. The cost of installing three HRS in 2020, serving a fleet of 14-24 trucks, would cost 16.0 – 17.6 million NOK/year more than a fleet based on biodiesel trucks. In a future scenario, where both the FCET and infrastructure costs decrease due to expected learning curves, a business case can be found if at least 5 FCETs were refueling at each HRS on daily basis, which corresponds to a total fleet of approx. 24 FCETs. Finally, a set of clear recommendations on how to improve the techno-economic analysis in future studies are provided. Both by identifying areas lacking sufficient documentation and by providing steps how the tecno-economic model could be enhanced. / Norge har redan en nästintill utsläppsfri elproduktion och nollutsläppsbilar stod för mer än 30% av nybilsförsäljningen under år 2018. En naturlig nästa utmaning är att finna sätt att minska utsläpp från lastbilar. I detta examensarbete analyseras möjligheterna att introducera bränslecellslastbilar (FCET) efter dess engelska förkortning) på sträckan Oslo - Trondheim genom att göra en teknisk-ekonomisk bedömning. Litteraturstudien visade att i genomsnitt 932 kton gods fraktas mellan städerna, att vägen genom Østerdalen är att föredra och att genomsnittlig last för en långtradare är 16 ton. Arbetets metod bygger på att identifiera kostnadskurvor för både lastbilar och infrastruktur. Dessa kurvor kombineras i olika scenarier för att finna omständigheter där både en FCET-flotta och dess infrastruktur är lönsamma. Kostnadskurvorna för lastbilar baseras på den totala ägandekostnaden (TCO) efter dess engelska förkortning) som en funktion av vätgaspriset, medan den utjämnade kostnaden för vätgas (LCOH) efter dess engelska förkortning) används för att presentera kostnaden för infrastruktur. En analys gjordes för att finna passande storlek på FCET drivlina. För den specifika sträckan krävs en hydrogentank på 46 kg, en bränslecellstack med nominell effekt på 200 kW, ett batteri på 100 kWh (min SOC 22%) och en elmotor med nominell effekt på 402 kW. TCO beräknades både för en FCET baserat på de dimensionerade komponenterna och en lastbil som går på biodiesel. En FCET som köps 2020 blir konkurrenskraftig om vätgaspriset är 38,6 NOK/kgH2, medan vätgaspriset kan öka till 71,8 NOK/kgH2 om FCET köps 2030. Skillnaden är baserad på en framtida prisnedgång för FCET. För att finna den mest lämpliga lösningen på infrastruktur; analyserades fyra olika utformningar av vätgaspåfyllningsstationer (HRS). I tillägg jämfördes vätgasproduktionsenheter (HPU) baserat på antingen alkalisk eller PEM-typ av elektrolysator. Resultaten visade at en 350 bar HRS utan kylning, som endast kan fylla typ III lagringstankar, som det billigaste alternativet. Den alkaliska elektrolysatorn kunde producera vätgas för något lägre kostnad. Det billigaste alternativet för infrastruktur av de olika framtagna scenarios var att placera HPU bredvid HRS om minst 7 FCET tankar dagligen på varje station. Minst 3 HRS krävs längs rutten för att tillhandahålla en minsta servicenivå för FCET. När TCO för bränslecellslastbil och LCOH för infrastruktur jämfördes för ett 2020-scenario så fanns det ingen lönsam lösning. Kostnaden för att installera 3 HRS år 2020 som betjänar en lastbilflotta mellan 14-24 lastbilar skulle kosta 16,0 - 17,6 miljoner NOK/år mer än en lastbilsflotta som går på biodiesel. I ett framtida scenario där både FCET- och infrastrukturkostnaderna minskar på grund av större produktionsvolymer så kan vätgassatsning bli lönsam om minst 5 FCET tankar dagligen på varje HRS. Det motsvarar en lastbilsflotta på omkring 24 lastbilar för hela rutten. Till slut finns en rad klara rekommendationer om hur den tekno-ekonomiska analysen kan förbättras. Det upptäcktes både områden med otillräcklig dokumentation och summerades hur den teknoekonomiska modellen kan förbättras.

The ever increasing demands of Internet users caused by the introduction of new high bandwidth applications and online services as well as the growing number of users and devices connected to the Internet, bring many challenges for the operators, especially in the last mile section of the network. Next generation access architectures are expected to offer high sustainable bandwidth per user. They also need to support a much larger service areas to decrease number of current central offices and hence potentially save the network expenditures in the future. Obviously, it requires high capacity and low loss transmission and optical fiber technology is the only future proof candidates for broadband access. Although this technology has already been widely deployed in the core networks, it is hard to use the same expensive devices made for core segment to solve the last mile bottlenecks, due to the low number of users sharing the network resources (and deployment cost). Therefore, the next generation optical access (NGOA) networks need to be designed with consideration of cost efficiency in the first place.   Network reliability is also turning to be an important aspect for the NGOA networks as a consequence of long reach, high client count and new services requiring uninterrupted access. Consequently, new architectures not only need to be cost efficient but also they should fulfill the increasing reliability requirements.   Although several NGOA alternatives have been proposed in the literatures, there is not yet an agreement on a single architecture. As described earlier, network expenditure and reliability performance are the two main factors to be considered. Therefore, this thesis concentrates on finding a suitable alternative for future broadband access by evaluating the reliability performance and total cost of ownership for several NGOA candidates. In particular, in this thesis we analyze the tradeoff between the cost needed to deploy backup resources and the reliability performance improvement obtained by the provided survivability mechanism.   First, we identified the suitable NGOA candidates by comparing two main groups of optical access networks, namely passive optical networks (PONs) and active optical networks (AONs), in terms of cost, reliability performance and power consumption. The initial results have shown that wavelength division multiplexing PON (WDM PON) is the most promising alternative for the NGOA networks because of its high potential capacity, low cost and power consumption. So we continued our studies by investigating two WDM-based PON architectures regarding their cost and reliability performance. The study has also included a proposed fiber layout compatible with these two candidates aiming to minimize the required investment needed to offer protection. Our primary results confirmed that hybrid PON (HPON) is the best alternative for the NGOA networks. Therefore we further analyzed this candidate considering several variants of HPON. The most important components and sections of the HPON, which need to be protected to decrease the impact of each failure in the network have been identified. Based on these outcomes, two resilience architectures protecting the shared part of the HPON were proposed and their reliability performance parameters as well as cost of protection were evaluated. According to the results, using our proposed protection schemes a considerable improvement in reliability performance of the HPON variants can be provided at minor extra investment. We also introduced a cost efficient HPON architecture with different levels of protection for users with various reliability requirements, i.e. the protection of shared parts of the access network for all the connected users and end-to-end resilience scheme for some selected ones (e.g., business users). To gain an overall view on the cost efficiency of the proposed architecture, we evaluated the investment required for deploying these schemes considering several network upgrading paths towards a protected network. Moreover, a sensitivity analysis investigating the influence of network deployments time and the density of the users with higher availability requirements was presented.   In summary, we have shown that HPON is able to fulfill the main NGOA requirements such as high bandwidth per-user, large coverage and client count. The work carried out in the thesis has proved that HPON can also offer high reliability performance while keeping the network expenditures at an acceptable level. Moreover, low power consumption and high flexibility in resource allocation of this architecture, makes it a winning candidate for the NGOA networks. Therefore, HPON is a promising architecture to be deployed as NGOA network in the near future considering the fact that components are soon to be available in the market. / <p>QC 20130530</p> / FP7 EU project, Optical Access Seamless Evolution(OASE)