Biogasanläggningar har oftast en relativt låg verkningsgrad och en låg lönsamhet, detta har gjort att biogasens potential inte utnyttjas till fullo utan används endast till några få procent globalt. Till följd av detta har Innovationsverket i Gamelby, i samarbete med KTH sedan hösten 2014 tagit fram en analys av hur ett framtida gårdsbaserat biogassystem kan se ut och samtidigt vara mer energioptimalt än dagens motsvarigheter. Företaget International Micro Biogas AB har skapats och patent har beviljats. Detta arbete syftar på att ta fram en komplett energianalys av ett småskaligt gårdsbaserat biogassystem utifrån dess huvudkomponenter, vilket har utförts genom att analysera tidigare examens- och projektarbeten som genomförts i samarbete mellan Innovationsverket och KTH, för att ur dessa dra ut relevanta delar och skapa det övergripande systemet. Energidata för de ingående huvudkomponenterna analyserades och beräkningar utfördes i Microsoft Excel. En Excelfil har skapats där det genom att ange gårdens antal kor går att beräkna den årliga energiåtgången för det gårdsbaserade biogassystemet, denna rapports resultat baserades på en gård med 200 kor. Sammanställningen av systemets huvudkomponenter resulterade i en energiåtgång på 385 MWh per år. Det nya gårdsbaserade biogassystemet har visat sig ha en god potential ur ett energiperspektiv och skulle med stor sannolikhet kunna bli självförsörjande om en optimering av systemet skulle genomföras. / Commercial biogas facilities often tend to have a relative low efficiency and low profitability, resulting in the worldwide biogas potential not being utilized to its full extent. Consequently, since autumn 2014, Innovationsverket in Gamelby has in collaboration with KTH analysed the potential of a farm-based biogas system compared to the energy efficiency of today’s equivalents. The company International Micro Biogas AB was started, and patents has been granted. This essay aims to conduct a comprehensive energy analysis of a small-scale farm-based biogas facility based on its main components, which has been performed by evaluating preceding master theses and project assignments conducted by the collaboration between Innovationsverket and KTH, with the goal of compiling information from these and creating the comprehensive system. The energy data of the main components were analysed, and calculations were conducted in Microsoft Excel. An Excel spreadsheet were one can insert essential farm data to calculate the yearly energy expenditure of a biogas facility has been created. This study was conducted with the intention of utilizing 200 cows as the essential data and the collection of the energy components output resulted in a yearly energy consumption of 385 MWh. The new farm-based biogas facility has displayed great potential, from an energy consumption perspective, and could with high probability become self-sufficient if an optimization of the system were conducted.

The world is now facing a transition from a fossil fuel dependent society to an energy sustainable one. This is happening by the world moving towards renewable energy resources and technologies. To realize and accelerate the transition, the key stakeholders of energy systems, such as the industries around the world needs to be involved and contribute to this transition. This paper investigates the possibilities of implementing on-site renewable energy technology solutions, for a medium-scale company in the developing country Sri Lanka. This company, Wijeya Newspapers Ltd., in particular has its own intention and vision of being 100% carbon neutral in their operations. This study keeps its major focus on the aspects of economical sustainability and technological feasibility but the environmental and societal impacts are investigated as well. Wijeya Newspaper’s printing factory form the base of this study and is located in Hokandaraarea outside the capital town Colombo. Among the options of renewable energy, the potential of solar power is large at the location and the area of the rooftop could generate 640 MWh electricity every year. As the factory is located in an urban area, the option wind power plant is not practical, due to poor wind conditions and other reasons. The bioenergy, in the form of biogas is produced in the factory by taking organic waste into an anaerobic digester. This generate a daily production of around 30 m3 biogas which could contribute to around 18 MWhelectricity on an annual basis. By looking at and analyzing data for the area and the factory’s operation alongside practical work, literature studies and calculations, the feasibilities of generating electricity from biomass, wind and solar energy was done. In conclusion, generating energy from biomass, solar and windpower on-site, is technically feasible but solar power and bioenergy are the only ones that could generate economic and environmental savings. However, neither of these renewable energy technologies will alone or in combination be able to supply the factory’s total energy demand, due to the practical limitations posed by the location. Among those three renewable options, also encouraged by Sri Lanka energy regulations and promotional efforts by the governmentfor solar energy in urban areas, the solar PV rooftop system has become the most economically feasible option.

Currently, the proliferation of electrified vehicles (EV) has increased rapidly. Considering EV users’ point of view, the duration of charging, and the place to charge their car are essential factors. Increase of EV penetration gives also impact on the electrical network such as overloading, and power quality issues. IEC 61851 and ISO 15118 are the two primary standards to provide requirements for electric vehicle supply equipment (EVSE) to ensure the process of charging can be adequately conducted without disrupting the electric system in general. Following standards and considering the user’s preference in charging place, a new charging method that can draw higher energy than existing technique should be developed. A three-phase grid connected home system is modeled in this study to see the impact of unbalance household load to a three-phase charging. The load modeling covers the variation level of load in summer, spring/fall, and winter. Specific usages of electricity are distributed in a three-phase home system which consists of phase 1: cold appliance, cooking, standby appliances, and other loads; phase 2: heat pumps, audiovisual (Television and sound system) and computer size; and phase 3: Lightning and washing. Two methods of charging are defined in this model, which are symmetrical (existing standard) and asymmetrical (proposed). In symmetrical technique, the On-board Charger (OBC) will draw equal phase current independent of home loads connected in each phase of three phase system. The three phase system will not balanced completely in this method. Meanwhile, in asymmetrical method, the OBC will draw the leftover of current in each phase according to its real-time availability by balancing all three phase in the home. The asymmetrical method is expected to achieve faster charging duration than symmetrical charging due to higher energy availability. There three main cases defined in this study: theoretical case (the EV is charged from hour 00:00), 0-100% SOC case, and the user case (the distance targeted determines Car Demand). The result of simulation reveals that Asymmetrical charging method can provide higher energy available than asymmetrical technique. Fuse-rating level influences a lot on this result. If the higher fuse rating applied in the same load profile, the gap of energy availability between symmetrical and asymmetrical will be reduced. But still the symmetrical method never perform better energy availability than the asymmetrical method, either with 16 A fuse and 20 A fuse. This result of energy availability becomes an indication for 3 the theoretical case, in which asymmetrical method can provide more charging cycles than the symmetrical method, especially for 16 A fuse system. For all cases that have been simulated, the asymmetrical method shows benefits in terms of reduction in time and cost reduction. In a year, the saving of hours of charging duration which could be achieved by new charging method in a 16 A fuse system is as high as 8 hours and 4 hours for 0-100% SOC cases and partial charging user cases respectively (less than 50% approx.). In a three-year cost comparison, the money that could be saved by the asymmetrical method in a 16 A fuse system are as high as 35 Euro for 0-100% case and 23,405 Euro in the user case. After simulations result obtained, asymmetrical method demonstrates a promising performance of the new charging technique in terms of duration and saving. There is a need to push a new standard to realize the implementation of this charging activity. A communication scheme between energy meter, EVSE, and OBC should be established to exchange real-time current availability information. New AC information sequences could be adapted from the DC charging communication standard, IEC 61851-24. / För närvarande har spridningen av elektrifierade fordon (EV) ökat snabbt. Att ta hänsyn till EVanvändarnas synvinkel, laddningstiden och platsen att ladda sin bil är väsentliga faktorer. Ökning av EVpenetration ger också inverkan på det elektriska nätverket, såsom överbelastning och problem med kraftkvalitet. IEC 61851 och ISO 15118 är de två primära standarderna för att tillhandahålla krav på elfordonsförsörjningsutrustning (EVSE) för att säkerställa att laddningsprocessen kan genomföras på ett adekvat sätt utan att störa det elektriska systemet i allmänhet. Efter standarder och med tanke på användarens preferens på laddningsplats bör en ny laddningsmetod som kan dra högre energi än befintlig teknik utvecklas. Ett tre-fas nätanslutet hemsystem modelleras i denna studie för att se effekterna av obalanserad hushållsbelastning på en trefasladdning. Lastmodelleringen täcker variationen i lasten på sommaren, våren / hösten och vintern. Specifika användningsområden för elektricitet distribueras i ett trefas hemsystem som består av fas 1: kallapparat, matlagning, standbylagare och andra laster; fas 2: värmepumpar, audiovisuella (TV- och ljudsystem) och datorstorlek; och fas 3: Blixt och tvätt. Två laddningsmetoder definieras i denna modell, som är symmetriska (befintlig standard) och asymmetriska (föreslagna). I symmetrisk teknik drar ombordladdaren (OBC) lika fasström oberoende av hembelastningar anslutna i varje fas i trefassystemet. Trefassystemet kommer inte att balansera helt i denna metod. Under tiden, i asymmetrisk metod, kommer OBC att dra återstoden av strömmen i varje fas enligt dess realtids tillgänglighet genom att balansera alla tre faserna i hemmet. Den asymmetriska metoden förväntas uppnå snabbare laddningstid än symmetrisk laddning på grund av högre energitillgänglighet. Det finns tre huvudfall definierade i denna studie: teoretiskt fall (EV debiteras från timme 00:00), 0-100% SOC-fall och användarfallet (avståndsinriktningen avgör bilfrågan). Resultatet av simulering avslöjar att asymmetrisk laddningsmetod kan ge högre tillgänglig energi än asymmetrisk teknik. Säkringsgraden påverkar mycket på detta resultat. Om den högre säkringsgraden som tillämpas i samma belastningsprofil kommer energiförbrukningen mellan symmetrisk och asymmetrisk att minska. Men fortfarande har den symmetriska metoden aldrig bättre energitillgänglighet än den asymmetriska metoden, varken med 16 A-säkring och 20 A-säkring. Detta resultat av energitillgänglighet blir en indikation för det teoretiska fallet, i vilket asymmetrisk metod kan ge fler laddningscykler än den symmetriska metoden, särskilt för 16 A-säkringssystem. För alla fall som har simulerats visar den asymmetriska metoden fördelar när det gäller minskning av tid och kostnadsminskning. På ett år är besparingen av timmar med laddningstid som kan uppnås genom en ny laddningsmetod i ett säkringssystem på 16 A så hög som 8 timmar och 4 timmar för 0-100% SOC-fall respektive partiell laddning av användarfall (mindre än 50% ungefär). I en kostnadsjämförelse på tre år är de pengar som kan sparas med den asymmetriska metoden i ett säkringssystem på 16 A så höga som 35 Euro för 0-100% fall och 23 405 Euro i användarfallet. Efter erhållna simuleringsresultat visar den asymmetriska metoden en lovande prestanda för den nya laddningstekniken när det gäller varaktighet och sparande. Det finns ett behov att driva en ny standard för att realisera genomförandet av denna avgiftsaktivitet. Ett kommunikationsschema mellan energimätare, EVSE och OBC bör inrättas för att utbyta information om aktuell tillgänglighet i realtid. Nya ACinformationssekvenser kan anpassas från DC-laddningskommunikationsstandarden, IEC 61851-24.

With the increasing amount of buildings that are being renovated in Austria, the potential of replacing conventional heating systems with heat pumps increases and thus CO2 emissions could be reduced. Several companies therefore focus on installing combined heat pump and PV systems. The installation of heat pumps and PV systems are being subsidized in Austria with different schemes for every state. The subsidy programs could therefore be clearer and more constant, like the Swedish heat pump subsidies of the last decades. Heat pumps currently cover the heating of over 10% of the gross floor area of single-family houses in Austria. For multifamily houses less than 5% of the gross floor area is heated with heat pumps. The research goal has been to analyze the sensitivity of the net present value (NPV), benefit cost ratio (BCR) and internal rate of return (IRR) on different input parameters for the replacement of a conventional heating system in a multifamily house, by a heat pump combined with a PV system. This way it could be researched what parameters would have most influence on the profitability of a combined heat pump and PV system. A case study has therefore been performed on the replacement of a gas heating system by an ambient air/water heat pump and a borehole ground source heat pump combined with a PV system in a multifamily house in Vienna. A model has been developed with Excel to perform this analysis uses the building space heating demand generated from a simulation tool created internally by AIT: The Building Model Generator. The model calculates the annual energy demand of a multifamily building in Vienna, which leads to the annual costs and benefits with respect to the conventional gas heating system. This model has been validated by a model created with the Polysun software. The results of the analysis showed that installing a combined heat pump and PV system to replace a gas heating system in a multifamily house would improve the NPV in comparison to installing the heat pump or PV system separately. The BCR is greater than one for both the combined air/water heat pump and PV system (AW HP+PV) and the combined ground source heat pump and PV system (GS HP+PV) for the currently used input. Subsidies currently have a large influence on the NPV and payback time of the installment of these combined systems, especially for the GS HP+PV due to the high investment subsidies for this type of heat pump in Vienna. The sensitivity analysis shows that the bigger the PV area of these combined systems, the higher the BCR, but this BCR increase flattens out for increasing PV areas. The investment costs have a large influence: if these would decrease somehow by 50%, the BCR would double. The large influence of the investment costs is shown by the sensitivity analysis on the assumptions for the heat pump investment costs as well. The electricity price has a larger influence on the BCR than the feed-in tariff does. When the electricity price decreases, the BCR increases. It could be concluded from the sensitivity analysis that the gas price has the largest influence however. Because of this high dependency on the gas price, a gas price increase could even make subsidies redundant. Increasing the gas price could thus be the quickest way to stimulate the sales of combined heat pump and PV systems, which could lead to a decrease of approximately 45%-60% of the total CO2 emissions for every multifamily house where these combined heat pump and PV systems are installed. In the future the Excel model could be included in the Building Model Generator. With only a few input parameters it would then be possible to evaluate the replacement of a heating system with another heating system in different building types for the whole of Austria where there are various subsidy schemes. / Med ökande antal byggnader som renoveras i Österrike, ökar även potentialen för att byta ut det konventionella värmesystemet mot värmepumpar. Således kan CO2-utsläpp minskas. Därför fokuserar flera företag på att installera kombinerade värmepump och PV system. Installationen av värmepumpar och PV system subventioneras i Österrike, men subventionerna kan vara klarare och mer konstant, som det har varit i Sverige under de senaste decennierna. För närvarande omfattar värmepumpar mer än 10% av uppvärmningen av den totala golvytan av enfamiljshus i Österrike. Beträffande flerfamiljshus motsvarar värmepumparna mindre än 5% av uppvärmningen av den totala golvytan. Forskningsmålet har varit att analysera känsligheten av nuvärdet (NPV), förmånskostnadskvoten (BCR) och den interna avkastningen (IRR) på olika inmatningsparametrar för ersättningen av ett gasvärmesystem i ett flerfamiljshus, mot en värmepump kombinerat med ett PV system. På så sätt kunde det undersökas vilka parametrar som har mest inflytande på lönsamheten av en värmepump och PV system. Därför utfördes en fallstudie på ersättningen av ett gasvärmesystem med en luft/vatten värmepump och en bergvärmepump kombinerad med ett PV system i ett flerfamiljshus i Wien. En modell har utvecklats med Excel för att utföra den här analysen använder byggnadsutrymmets värmeefterfrågan som genereras av ett program som har skapats internt av AIT:s Building Model Generator. Excelmodellen beräknar det årliga energibehovet av ett flerfamiljshus i Wien, som leder till de årliga kostnaderna och fördelarna med avseende på ett konventionellt gasvärmesystem. Excelmodellen har validerats med en modell som har skapats med mjukvaran Polysun. Resultaten av analysen visade att installera ett kombinerat värmepump- och PV system för att byta ut ett gasvärmesystem i ett flerfamiljshus skulle förbättra NPV-värdet jämfört mot att installera ett värmepumpeller PV system separat. Resultaten visar att, för de aktuella inmatningarna, BCR-värdet är större än ett för både det kombinerade luft/vatten värmepump- och PV systemet (AW HP+PV) och det kombinerade bergvärmepump- och PV systemet (GS HP+PV). För närvarande har subventioner en stor påverkan på NPV-värdet och återbetalningstiden av installationen av dessa kombinerade system, framförallt på GS HP+PV på grund av höga investeringssubventionerna av den här typen av värmepumpar i Wien. Känslighetsanalysen visar att desto större PV-yta av dessa kombinerade system, desto högre BCR-värde, men ökningen plattas ut för ökande PV-ytor. Investeringskostnaderna har stort inflytande: om dessa på något sätt skulle minska med 50%, skulle BCR-värdet fördubblas. Den stora påverkan av investeringskostnaderna visas även i känslighetsanalysen av antagandena för investeringskostnader för värmepumpen. Inmatningstariffen har inte stort inflytande på BCR-värdet. Elpriset har en större påverkan än inmatningstariffen. När elpriset sänks, ökar BCR-värdet. Från känslighetsanalysen kan slutsatsen dras att gaspriset har största inverkan. På grund av den här stora påverkan av gaspriset, kunde även en gasprisökning göra subventioner överflödiga. Att öka gaspriset kunde således vara det snabbaste sättet att stimulera försäljningen av kombinerade värmepump och PV system, som kan leda till en minskning av ungefär 45%- 60% av totala CO2 utsläppen för varje flerfamiljshus där dessa kombinerade värmepump och PV system är installerade. I framtiden kan Excelmodellen komma bifogad i Building Model Generatorn. Med några få inmatningar kommer det sedan vara möjligt att värdera ersättningen av ett värmesystem med ett annat värmesystem i olika byggnadstyper i hela Österrike där flera subventioner gäller.

According to the Intergovernmental Panel on Climate Change, an increase in global temperature to above 1.5°C can be halted but would require immediate intervention to reach net zero emissions in the next 15 years. This intervention would have to make use of sustainable energy technologies such as net-zero carbon systems for automobiles. Electric vehicle (EV) use is set to increase 3000% between 2016 and 2030. Due to the inherent toxicity of the chemicals within Li-ion batteries, they must be recycled to be sustainable. Recycling using energy recovering, hydrometallurgical process reduces greenhouse gas emissions. However, due to the high energy and power density within EV batteries, discharging the batteries is an important safety step in the pre-treatment process. There is no industry standard for discharging EV batteries. Many processes are suggested in literature with little information as to the methods used. The aim of this thesis is to explore four processes that could be suitable for industrial use. A suitable process should be ‘safe’, meaning it reduces the risk to the facility by minimizing the fire or explosion hazard, minimizes or eliminates human interaction with the battery pack and limits voltage rebound of an individual cell to 0.5V. The process should also be ‘rapid’, meaning it ensures that discharging does not become a bottleneck in recycling, ‘sustainable’ meaning it has no polluting fluid waste streams and ‘feasible’ that is, is cost efficient. Three processes were found effective. The first, is a combination of salt-solution and metal powder discharge methods using sodium carbonate and steel. This method is intended for battery packs and modules of less than 500V at 0% SOC. The second, is energy recovering electronic load discharge for battery backs greater than 500V or at greater than 0% SOC.  Finally, inductive, wireless discharge with BMS ‘override’ is suggested. This method is suitable for future battery packs of all sizes equipped with wireless charging technology.

The work of this thesis is focused on creating the base for developing new hydraulic systems for mobile machinery tailored for an electric drive system. The loader crane is used as the principal application. With batteries being costly to invest in and having a much lower energy density than diesel fuel, the new systems must significantly reduce the energy consumption compared to the conventional system while keeping the performance in order to enable an electric drive. Exactly how much more energy efficient a new system must be will differ with the use case of the application, and with time, as components and the market develop. The aim is therefore to present a large number of new system concepts with different levels of energy reducing capabilities and complexity rather than proposing a single solution.  In order to be able to evaluate and compare different system solutions, a drive cycle for the working envelope of the loader crane is developed. The drive cycle includes as much variance of the movement as possible in a short time, which is of practical use when testing prototypes.  The task of finding new energy efficient solutions is started by performing a loss analysis on the reference crane. The analysis shows that losses due to simultaneously operated functions are significant, and consequently that multi-pump systems are of interest. A concept study that looks deeper into multi-pump systems as well as other loss-reducing concepts is carried out, and a large number of new system solutions with different energy reducing potential are presented.  A promising concept is the two-pump system with open flow control, which is investigated in more detail by building and testing a prototype. The results from operation of the prototype highlight the challenge of achieving smooth control, but also that the efficiency is indeed improved compared to the refer-ence system.  As this work is part of a larger research project, studies have been conducted on other interesting concepts as well, but with different applications. Results from these that are relevant to the loader crane case are discussed together with the results from the studies included in this thesis, in order to give a broad view on how a suitable system can be selected for the intended application. / <p>2023-04-14: ISBN (PDF) has been added in the E-version.</p>

This bachelor's thesis explores the potential of Skolfastigheter's facilities to achieve self-sufficiency through solar power while maintaining economic feasibility. The study specifically examines the economic feasibility of various solar power installation sizes, while also exploring key characteristics of school facilities that influence their level of self-sufficiency. To assess this, the report is structured into several steps. The initial step involves identifying properties with the potential to achieve Skolfastigheter's objective of being 15 % self-sufficient and subsequently ranking them. The following step involves evaluating the maximum potential self-sufficiency of a few selected properties through an optimization problem, with an upper limitation in investment cost and maximal capacity. Once optimal self-sufficiency is detected and evaluated a sensitivity analysis is conducted to test the model's robustness by considering different electricity prices and orientations. The results indicate that fluctuating electricity prices have a significant effect on the potential size of the solar panel system, while the orientation has a minor effect when optimizing for self-sufficiency. The key characteristic for achieving optimum self-sufficiency is an even consumption pattern throughout the year, and the facility size is mainly dependent on the current electricity pricing. Furthermore, it is highly probable that the current 15% self-sufficiency threshold for Skolfastigheter AB can be surpassed.

A society with interconnected energy sectors may be a contributing factor to reduce carbon dioxide emissions, while simultaneously meeting the increasing demand for electric energy. This study investigates the possibilities to link a sea-based wind farm with hydrogen gas production in addition to serving as a support function to a transmission systems operator. Using a custom-built model, this interconnected system is simulated for different scenarios where the wind farm, electrolyser and the balanced power market are observed. The model takes into account the economic potential and the different ways of producing hydrogen gas, while also discussing the potential significance of interconnected systems such as this.  The result indicated that the economic viability in constructing an interconnected system such as the one included in the study is substantially dependent on the variability of the price for electricity. It is also concluded that out of the modelled scenarios, two could be considered to have the possibility to become economically viable. One case consisted of an electrolyser being fed electric power directly from the wind farm, where the system was constantly available to act as a support system to the power grid. The other scenario considered viable based on the results was when the electrolyser was fed with electric power from the grid and set to be available to run while the spot price was below a threshold value.  While the parameters used for sizing the system in the model cannot be considered to be optimized in all cases, the size of the electrolyser did not significantly affect the result of the simulated scenarios.

This bachelor thesis will examine the actions that have been taken to lower the electricity use at Uppsala University Hospital during the winter of 2022/2023. To be able to evaluate the changes that have been done there will be a comparison between the winter of 2022/2023 and the winter of 2021/2022. During the recent winter Uppsala University Hospital made two different types of changes to make the electricity use decrease. Firstly, they continued with implementing technical changes which involves for example switching regular lights to LED-lights and ensuring that fans are operating efficiently. Secondly, they sent out information to every department through their website, newsletters, and other information sources. They also urged every department’s environment coordinator to spread awareness about the energy crisis and how to save electricity by creating behavioral changes as well. It was discovered that Uppsala University Hospital lowered their electricity use by 5,62% the winter 2022/2023 compared to the winter 2021/2022. However, the result that was concluded from this project was that it was quite difficult to distinguish how much behavioral changes contributed to the decrease. The only time it was possible to distinguish this was when bigger actions were taken, for example turning of the sauna. In most cases it was the technical changes that contributed the most to the decrease of electricity use.

To tackle the global sustainability challenge, the energy system needs to transition towards a sustainable system, since it is responsible for two-thirds of global greenhouse gas emissions. To reduce emissions researchers urged for a 100% renewable based energy system, in which photovoltaic (PV) energy production is seen as a key component. Social aspects should be considered and participation from individuals is needed. This thesis aims to answer the question“How can small-scale photovoltaics (SSPV) contribute to a transition towards a sustainableenergy system?” The case of Austria and Sweden. This thesis conducted 10 in-depth semistructured qualitative interviews from each country, applying PESTLE framework in coding. Results were assessed through a unique combination of Backcasting as a lens, eight Sustainability Principles (8 SPs), and PESTLE. SSPV enables individual contribution to the energy transition. SSPV has a limited role to play in the energy system in Austria, but even more limited in Sweden. Both countries are currently overwhelmed with the demand for SSPV. Since SSPV is not sustainable according to the 8 SPs the method of Backcasting should be repeatedly applied for SSPV to assess if this trend is truly contributing to a sustainable energy system.