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  • 201. Angwald, Filip
    Power mapping and aggregation as a service: A techno-economic view on Li-ion batteries for peak shaving and frequency regulation2020Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The world's energy supply today mainly consists of fossil fuels and nuclear power. Moving away from the use of these energy resources to renewable energy sources is considered a prerequisite for a sustainable future. In order to implement this change, it is necessary for renewable energy sources to be environmentally, technically and economically sustainable. A major challenge encountered in terms of technological sustainability is the intermittent nature of renewable energy sources. As the share of renewable electricity increases in the system, the electricity grid is facing new challenges such as increased instability of the frequency and capacity shortages. In order to meet these new challenges an increased flexibility from electricity users is proposed as a solution. Flexibility can be achieved either by controlling the use of electricity or utilizing energy storages. If different electric loads are to be controlled in a property, data regarding the power use of the loads must first be collected with a high time resolution in order to be able to properly analyze the data. Measures to shift or reduce the power peaks in a property can then be suggested and implemented. A battery storage can help reduce power peaks or shift loads in time and if done on a large scale that would reduce the strain on the entire Swedish grid. One of the ancillary services that the battery could offer is frequency regulation. Using energy storages for such an application could also provide a secondary revenue stream, aside from the revenue stream from peak shaving, and increase the profitability of the storage. Sweden has seen a dramatic increase in electric vehicles over the last decade and charging of the vehicles has become an issue for many property owners as it often creates power peaks. The data collection regarding power use in properties performed in during this thesis showed that valuable data can be collected with the method and material used. With a battery price of 3000 SEK/kWh the payback time for a battery system can be reduced from 17,9 to 7,8 years if it is used for frequency regulation during the night. If power-intensive loads such as electric vehicle charging are added to the model the payback period decreases to 6,1 years. With these results in mind, it can be concluded that the profitability of a battery storage can increase to the extent that the investment is of economic viability. In addition, the investment helps to improve the stability of the Swedish grid. The results are found to be relatively consistent with those of other similar studies.

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  • 202. Anh, N. T.
    et al.
    Van Hertem, Dirk
    KTH, School of Electrical Engineering (EES), Electric Power Systems. K.U. Leuven, Belgium .
    Driesen, J.
    Transient stability enhancement by TCSC controllers using remote input signals2010In: 2010. ACDC. 9th IET International Conference on AC and DC Power Transmission, 2010, no 570 CPConference paper (Refereed)
    Abstract [en]

    This paper presents a method to improve the dynamic performance of Thyristor-Controlled Series Capacitor (TCSC) regarding transient stability using remote measurement signals. The remote signals are selected based on their effectiveness for damping the first swings. Phasor Measurement Units are used to measure real-time remote signals and transfer those to the TCSC stability control loop. Transient stability studies are performed for the Vietnamese system, and the benefits of applying TCSCs for the stability enhancement are demonstrated. The case studies show the enhancement of the transient stability comparing control using remote control signals in stead of local signals.

  • 203.
    Anshelm, Jonas
    et al.
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Ellegård, Kajsa
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Palm, Jenny
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Rohracher, Harald
    Linköping University, The Tema Institute, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Socio-technical perspectives on sustainable energy systems2015Book (Other academic)
  • 204.
    Anshelm, Jonas
    et al.
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Galis, Vasilis
    IT University, Copenhagen, Denmark.
    (Re-)constructing nuclear waste management in Sweden: the involvement of concerned groups2015In: Socio-technical perspectives on sustainable energy systems / [ed] Jonas Anshelm, Kajsa Ellegård, Jenny Palm, Harald Rohracher, Linköping: Linköping University , 2015, p. 241-283Chapter in book (Other academic)
  • 205.
    Anshelm, Jonas
    et al.
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Hansson, Anders
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Climate change and the convergence between ENGOs and business2015In: Socio-technical perspectives on sustainable energy systems / [ed] Jonas Anshelm, Kajsa Ellegård, Jenny Palm, Harald Rohracher, Linköping: Linköping Unversity , 2015, p. 285-306Chapter in book (Other academic)
  • 206.
    Antila, Eric
    Halmstad University, School of Business, Innovation and Sustainability.
    SunTrack2021Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    For many of us, electricity is a natural and necessary source, making it easier to go about our everyday life. Imagine having to collect firewood, for several hours a day, to be able to carry out such a simple task as preparing a meal. For many people, especially in developing countries, everyday life looks just like that, but it does not have to. In line with the increasing demand of sustainability, new technologies now turn their focus to the almost inexhaustible source of energy, namely the sun.

    The energy that is being received every day in the form of solar radiation, corresponds to about 8000 times more energy than what is being consumed on the planet, throughout anentire year. With today's technology, there is now a possibility to farm parts of this energy, to be used as a more sustainable alternative. 

    Sunfurias product uses a technology that, with the help of solar collectors, saves solar energy in a heat storage, enabling cooking at any time.

    For the solar collectors to be as efficient as possible, they need to rotate following the movement of the sun throughout the day. Today, this is done by using an advanced tracking device, which in turn makes the entire product significantly more expensive. Which also affects the sales volume, especially in the developing countries.

    The SunTrack project has been carried out in collaboration with Sunfuria AB to solve the need for a more affordable product, by developing a cost-effective alternative to the current solar tracking system.

  • 207.
    Anttila, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Electrical Engineering, Electricity.
    Döhler, Jéssica
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Electrical Engineering, Electricity.
    Oliveira, Janaína Goncalves de
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Electrical Engineering, Electricity. Univ Fed Juiz de Fora, Dept Elect Energy, BR-36036330 Juiz De Fora, Brazil..
    Boström, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Electrical Engineering, Electricity.
    Grid Forming inverters: A review of the state of the art of key elements for microgrid operation2022In: Energies, E-ISSN 1996-1073, Vol. 15, no 15, article id 5517Article, review/survey (Refereed)
    Abstract [en]

    In the past decade, inverter-integrated energy sources have experienced rapid growth, which leads to operating challenges associated with reduced system inertia and intermittent power generation, which can cause instability and performance issues of the power system. Improved control schemes for inverters are necessary to ensure the stability and resilience of the power system. Grid-forming inverters dampen frequency fluctuations in the power system, while grid-following inverters can aggravate frequency problems with increased penetration. This paper aims at reviewing the role of grid-forming inverters in the power system, including their topology, control strategies, challenges, sizing, and location. In order to facilitate continued research in this field, a comprehensive literature review and classification of the studies are conducted, followed by research gaps and suggestions for future studies.

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  • 208. Anttila, Sara
    et al.
    Silva, Dalmo
    Temiz, Irina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Oliveira, Janaína Goncalves de
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Leijon, Jennifer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Parwal, Arvind
    Boström, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Power Control Strategies for a Smoother Power Output from a Wave Power Plant2019In: European Wave and Tidal Energy Conference (EWTEC), Napoli, Italy: European Wave and Tidal Energy Conference , 2019Conference paper (Refereed)
  • 209.
    Antón, Raúl
    et al.
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik. Royal Institute of Technology, Stockholm, Sweden; TECHUN, University of Navarra, San Sebastián, Spain.
    Jonsson, Hans
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik. Royal Institute of Technology, Stockholm, Sweden.
    Moshfegh, Bahram
    University of Gävle, Department of Technology and Built Environment, Ämnesavdelningen för energi- och maskinteknik.
    Detailed CFD modelling of EMC screen for radio base stations: A conjugate heat transfer problem2007In: International Journal of Heat Exchangers, ISSN 1524-5608, Vol. 8, no 1, p. 95-116Article in journal (Refereed)
    Abstract [en]

    The objective of this paper is to perform an experimental as well as CFD investigations of the conjugate heat transfer problem in a sub-rack slot model. A steady-state three-dimensional detailed model, which serves as the most accurate representation of the model, was used in order to evaluate the details of the airflow paths and temperature field. A general model that covers a considerable range of velocities, screen porosities and heat fluxes was validated experimentally by wind tunnel measurements. The result shows that the RNG k-ε model used with correct y+ and mesh strategy accurately predicts the temperature field. The average temperature deviation at several locations is less than 4% compared to experimental data. The influence of the velocity, screen porosity, heat flux and presence of the EMC screen on the PCB temperature field is commented. © 2007 R.T. Edwards, Inc.

  • 210.
    Anukam, Anthony
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Berghel, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Henrikson, G.
    Frodeson, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    Ståhl, Magnus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Chemical Sciences (from 2013).
    A review of the mechanism of bonding in densified biomass pellets2021In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 148, article id 111249Article in journal (Refereed)
    Abstract [en]

    The production of durable biomass pellets have always been challenged by several factors including the lack of understanding of the mechanism involved in how particles combine to form pellets under standard conditions of the pellet press. This is because contributing factors span several molecular, microscopic, and even nanoscopic levels as biomass undergoes pelleting. The characteristics of the bonds formed between the combining particles and their relevance to the quality of pellets remains vague, no matter how quality is defined. However, even though few researchers have attempted to explain the mechanism of bonding in densified biomass pellets using different theories, none of their hypotheses supports particle bonding from a structural chemistry perspective. There are still no clear explanations which consider the role of molecular structure and the interactions of substances as milled biomass undergo pelleting. In view of these arguments therefore, this review presents an in-depth analysis of a structural chemistry perspective of the mechanism of bonding and the use of additives in densified biomass pellets and helps identify research areas needed to facilitate better understanding of bonding in densified biomass pellets. The status of current research in biomass pelleting, types of materials suitable as additives and their structural characteristics, as well as the current technical specifications of using additives are also discussed.

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  • 211.
    Anukam, Anthony
    et al.
    Univ Ft Hare, South Africa.
    Meyer, Edson
    Univ Ft Hare, South Africa..
    Okoh, Omobola
    Univ Ft Hare, South Africa..
    Mamphweli, Sampson
    Univ Ft Hare, South Africa..
    Gasification characteristics of sugarcane bagasse2012In: PROCEEDINGS OF SAIP2012: THE 57TH ANNUAL CONFERENCE OF THE SOUTH AFRICAN INSTITUTE OF PHYSICS / [ed] J. J. VanRensburg, SOUTH AFRICAN INST PHYSICS , 2012, p. 464-471Conference paper (Refereed)
    Abstract [en]

    Sugarcane bagasse is a residue that results from the crushing of sugarcane in the sugar industry. Among the various agricultural crop residues, sugarcane bagasse is the most abundant lignocellulosic material in tropical and sub-tropical countries including South Africa. Bagasse is a renewable feedstock that can be used for power generation and manufacturing cellulosic ethanol In the sugarcane industries the bagasse is mainly burnt inefficiently in boilers that provide the heating for the industry. This project seeks to investigate the possibility of gasifying sugarcane bagasse as an efficient conversion technology. Proximate and ultimate analysis of sugarcane bagasse was conducted after which the results were used to conduct computer simulation of the mass and energy balance during gasification. This paper presents the proximate and ultimate analysis as well as the computer simulation results.

  • 212. Aoun, M. -C
    et al.
    Pešut, D.
    Matosović, M.
    Bošnjak, R.
    Deane, P.
    Glynn, J.
    Gallachóir, B. Ó
    Nagy, S.
    Badouard, T.
    Desbrosses, N.
    Taliotis, Constantinos
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems Analysis.
    de Boncourt, M.
    Keramidas, K.
    Gas Security of Supply in the European Union2017In: Europe's Energy Transition: Insights for Policy Making, Elsevier, 2017, p. 67-78Chapter in book (Refereed)
    Abstract [en]

    The EU remains widely dependent on external gas supplies, with imports representing 70% of its consumption in 2013. Member States have different import profiles with divergent levels of dependency on Russian imports. Several European Member States rely heavily on Russian supplies, which shows that the EU gas supply security needs to be examined both from an internal and international perspective. Since the 2009 crisis between Russia and Ukraine, the EU has adopted several legislative tools to strengthen EU gas security of supply. The third legislative package, the security of supply Regulation (EU) 994/2010 and the Energy Infrastructure package identifying Projects of Common Interest have significantly improved the ability of the EU to face import disruptions. However, several countries remain particularly vulnerable to the occurrence of disruption. When considering national production, storage, and the diversity of suppliers, Bulgaria, Czech Republic, Estonia, Finland, Latvia, and Lithuania seem to be at risk. Romania, Poland, and Hungary also import the bulk of their gas from Russia, but have either domestic production or significant storage capacity.

  • 213.
    Apelfröjd, Senad
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Bülow, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Kjellin, Jon
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Eriksson, Sandra
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Laboratory verification of system for grid connection of a 12 kW variable speed wind turbine with a permanent magnet synchronous generator2012In: EWEA 2012 Annual Event, Copenhagen, Denmark, 2012, 2012Conference paper (Refereed)
    Abstract [en]

    In this paper the first laboratory tests of the gridconnection system, connected to a resistiveload, for a vertical axis wind turbine (VAWT)with a permanent magnet generator arepresented. The system is based on a taptransformertopology with a voltage sourceinverter and an LCL-filter. The use of a taptransformer topology eliminates the need for aDC-DC converter to handle the variations inDC voltage. The harmonic content of thecurrents from experiments and simulationsperformed in Simulink using different taps onthe transformer are presented. The simulatedcurrents, fed to the resistive load, have a totalharmonic distortion (THD) of 0.5% to 0.9% forthe different taps. The experimental systemhas a current THD ranging from 1.8% to 2.8%.The difference is expected to be due tounbalances, delays and dead times in theexperimental set-up as the major THDcontribution is from harmonic orders below 11.The results show that an LCL filter can bedesigned to meet the demands on powerquality for grid connection of the system withall the taps of the tap transformer inaccordance with IEEE 519-1992.

  • 214.
    Apelryd, Caroline
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Civil and Industrial Engineering, Civil Engineering and Built Environment.
    Säsongslagra el med vätgas: Ekonomiska möjligheter för långtidslagring av grön vätgas producerad ur vindkraft2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The energy carrier hydrogen has a great advantage over other electricity storing techniques on the market: the ability to store electricity long-term without any geographical needs. Though today’s techniques available are of low efficiency, the interests for them are high. Hydrogen gas is versatile, and with future developments it is possibly to make great economical profit from having a hydrogen storage. This master thesis project is evaluating the possible profitability that can be made when connecting a hydrogen system to a wind farm located in Swedish electricity region SE1. 

    The system contains of production, storage and cold combustion of hydrogen with one main purpose: to produce hydrogen through electrolysis when the electricity prices are low and convert the gas back to electricity to sell when the prices are high. Four different simulations are made with a mixture of incomes: using the variety in the electricity price over a year, selling the by-products from the hydrogen system and selling pure hydrogen gas. 

    The different simulations are mainly compared through three values: levelized cost of hydrogen (LCOH), earnings before interests and tax (EBIT) and return. The results show that the LCOH -cost per produced kilo hydrogen- for all simulations are higher than other compared production methods; even higher than the price per sold kilo hydrogen. EBIT -earnings per year- show that selling pure hydrogen gas makes a major difference on the yearly profit, from (the lowest result) -52217 SEK to (the highest result) 4853306 SEK. Even though EBIT show a positive result for some of the simulations, the return on the investment is negative which makes the investment non-profitable. In a sensitivity analysis with three variables, is the one who makes the biggest difference on the return value the cost of the hydrogen storage. Lowering that cost enough would make the investment profitable. 

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  • 215.
    Apelryd, Caroline
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Civil and Industrial Engineering.
    Hrnjez, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Civil and Industrial Engineering.
    Ranglén Svärdström, David
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Civil and Industrial Engineering.
    A modern way of traveling: Sustainable mobility in Rosendal2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report aims to investigate the economical possibilities of implementing mobility services, such as electrical carpool and electrical bicyclepool, in the upcoming mobility house Brandmästaren in Rosendal, Uppsala. A model based on a travel habit survey in Uppsala has been developed in order to calculate the need of vehicles. Thereafter the financial profits are calculated depending on the need of vehicles and according to different scenarios regarding how many people that potentially will join the mobility hub. The profits are then compared to the profits from a conventional parking house, in order to decide whether the mobility system is economically viable. The results concluded the following. The most suitable mobility system for Rosendal includes 104 bicycles, 36 cargo bicycles and 94 cars. For a supplement rent of 50 SEK per user connected to the mobility center, the break-even point for the business model where bicycles are rented is when 30.56% of the residents are connected to the system. For the business model where bicycles are bought the break-even point is 18.28%. A sensitivity analysis on the number of hours the service is assumed to be used showed that the profitability would not change to a significant extent. The highest break-even point after the sensitivity analysis was 34.40%. After comparison to other mobility services in Sweden, the conclusion was that the number of connected users needed was relatively low, hence the results shows that the mobility house has the potential of being more profitable than conventional parking house.

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    Independent project 15 hp
  • 216.
    Appelstål, Sophia
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Teknisk utvärdering av befintliga och potentiella teknologier för automatisk frekvensreglering i det svenska elnätet2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The increasing amount of renewable energy in the power system have led to new challenges to balance supply and demand in the electric grid. To maintain the balance in the power system the system operator can activate power reserves to restore the balance at a frequency deviation. Today these reserves consist exclusively of hydropower in Sweden. With more volatile power generation new types of technologies to provide these reserves are desirable.

    The aim of this master thesis is to investigate the technical potential for using wind power, demand response and energy storage for automatic frequency control in the Swedish power system. The thesis examines the performance of the different technologies to see if they meet the technical requirements for delivering reserves set by the TSO. Moreover, the available capacity from the technologies throughout the year are estimated.

    The results show that all three technologies potentially could be used for frequency control. However, the technical requirements are not always fulfilled. In order to enable new technologies to provide power reserves some of the requirements needs to be modernized. Generally, demand response proved to have the largest available capacity for frequency control today. The study shows that demand response from industries and electric heated households could potentially provide all automatic frequency control. Modern wind turbines can be used for frequency control and for down regulation of the frequency the potential is considerable. Energy storages are not yet widely used in Sweden but with reduced costs they can play an important role in regulating the frequency in the future.  

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  • 217.
    Arana, Eneko
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Energy improvement options for a small-scale brewery: a literature study2022Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the age of technology and development in which we live nowadays, it is inevitable to realise that this so-called progress is translated into pollution, damage to the environment and abuse of energy and fossil fuels. The companies and factories that produce the goods we need, use a lot of energy and pollute in massive ways, posing dilemmas such as how to make these companies more energetically and environmentally efficient, with the aim of decreasing the emissions and energy use. This literature review proposes a compilation and update of suggestions made to microbreweries after undergoing an energy audit, in an attempt to make these companies more energy-efficient, competitive, economical and sustainable. The information has been obtained by searching peer-reviewed articles in different databases and re-arranged in this article into sections on energy efficiency measures, waste treatment options and environmental impact. Several studies have been carried out on improving efficiency and trying to decrease the environmental impact of beer production processes. The main issues found during the process are energy efficiency and the generated wastewater. Both problems could be solved either by using an internal boiler that would generate less waste, applying renewable energies or by treating the residues in bioreactors, a field that needs further study. The choice of packaging material will be influenced by customer preferences and material recycling, being glass bottles and aluminium cans the most popular choices. 

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  • 218.
    Aranaga Decori, Pierre Ander
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science.
    Implementation of energy recovery and storage systems in cranes in the Port of Gävle2020Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Container traffic in seaports around the world in constantly increasing, with energy costs being a significant part of the total costs. The container terminal (CT) of the Port of Gävle, the largest in the east coast of Sweden, is not an exception to this. With traffic growing annually, a new terminal will be opened in the following years, adding three more ship-to-shore (STS) cranes to the two existing ones, and six electric rubber tyred gantry (eRTG) cranes. Therefore, it is highly important to strengthen energy efficiency measures, reducing the energy consumption and the costs associated with it. This is why the aim of this report is to analyse whether implementing energy storage systems in the cranes of the container terminal Port of Gävle can contribute to reduce electricity costs by recovering energy when braking lowering containers, and by shaving power peaks. After a literature review of current energy recovery and storage options, this work presents three solutions: two alternatives for the current situation with two ship-to-shore (STS) cranes, and a third solution to be implemented in the three future STS cranes to be installed, which can also be beneficial for any other crane in the terminal. According to the made calculations, the three alternatives can reduce considerable energy consumption, and they are highly profitable. However, those solutions are a preliminary study and more work needs to be done to determine the exact profitability and technical system details. This work has been done in collaboration with the Port of Gävle and Yilport, the company operating the container terminal.

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    Implementation of energy recovery and storage systems in cranes in the Port of Gävle
  • 219.
    Arango Munoz, Paty
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemical Engineering.
    Stripper Modification of a Standard MEA Process for Heat Integration with a Pulp Mill2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The 20 largest pulp mills in Sweden emit around 20 million tonnes of CO2 per year. These emissions are considered carbon-neutral since they originate from biogenic sources. The pulp and paper industry is therefore a good candidate for the application of BECCS (Bioenergy with Carbon Capture and Storage) and has the potential to play a significant role for reaching the long-term mitigation target set by the Swedish government that Sweden should be climate-neutral by year 2045. In this thesis, a MEA-based chemical absorption and desorption process was rigorously modelled in Aspen Plus using the rate-based method.

    Validation of the absorber and stripper model was conducted before the standard process was modified to a configuration that enables heat integration of a significant amount of excess heat from the capture process in, for example, a Kraft pulp mill. CO2 removal rate and rich solvent loading were used as performance indicators to validate the absorber columns. The reboiler duty and lean solvent loading served as performance indicators in the stripper validation. The columns were dimensioned considering 90 wt% capture rate. Efficient use of the entire packing in the absorber and stripper columns was ensured by testing different solvent flow rates.

    Suitable temperature levels for heat integration, within and across the capture plant, were obtained through an assessment of different versions of a stripper overhead compression configuration. The evaluation of the modified MEA processes took into account the steam conservation potential and energy efficiency potential. The simulation results indicate that the modified stripper may lead to savings of up to 11% in steam consumption. Heat integration between the capture plant and a specific process in a reference Kraft pulp mill resulted in energy savings of the same order of magnitude. Thereby, making the BECCS concept a more attractive solution for the Swedish pulp and paper industry to mitigate climate change.

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  • 220.
    Arbman Hansing, Anton
    et al.
    Handelshögskolan i Stockholm.
    Fridahl, Mathias
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Centre for Climate Science and Policy Research, CSPR.
    European and Swedish point sources of biogenic carbon dioxide2018In: Bioenergy with carbon capture and storage: from global potentials to domestic realities / [ed] Mathias Friman, Bryssel: European Liberal Forum , 2018, Vol. Sidorna 31-43, p. 31-43Chapter in book (Other academic)
    Abstract [en]

    Acknowledging the climate scenarios’ future deployment of BECCS in Europe and modelers’ questions as to the feasibility of implementing the level of BECCS proposed in the scenarios, this chapter provides a crude estimate of?the existing European potential for BECCS.?This potential is estimated through mapping point sources of biogenic CO2 from three types of processes with particularly promising prospects for BECCS: production of paper and pulp, combined heat and power (CHP), and bioethanol. The production of pulp, paper, and paperboard (“pulp and paper” for short)?is very energy intensive and generates considerable CO2 emissions. Due to?improved energy efficiency and a switch from fossil fuels to in-house biomass-based fuels, a large proportion of these CO2 emissions are biogenic (Sun et al., 2018). This, in combination with the fact that the emissions are often concentrated in just a few large production plants, makes these industries promising for BECCS deployment.

  • 221.
    Archakis, Viktor
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    The Design of a Passive House2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    About 25 % of the total buildings in the European Union have been categorized as ”old buildings”. Followed the recent strickt rules for carbon emissions reduction, each house has to approximetely cut 20 % of CO2 by 2020. Countries like England, have taken the issue very seriously and planning to reduce the carbon emissions by 30 % until the end of 2020 and by an extra 80 % by 2050 (Francis Moran, 2014). The aim of the report is to present how a traditional house can be retroffited into a passive house and also to identify the key points that every passive house should have. For the purpose of the project an avtual house, based in Gävle, was provided and all the simulations are based on actual data. The initial design of the house which was used for the simulation and the 3D design, was provided by the house owner. The building was built in 1953, information regarding the current insulation of the house was provided by the owner as well. For the simulations and the 3D design a software know as IDA ICE was used, license and access to the software were given by the University of Gävle. The report simulates the current house and compares the results with two possible scenarios that are reducing the energy demand of the house. Furthermore, the possible ways and tools that could be used to reduce the energy demand of the house and cost estimation for the retrofitting is available in the paper.The first simulations were occured on the actual house, the first retrofitting package introduces new simulations based on new insulation materials, like wood and cement, that are placed mainly on the roof and on the outer walls. Also, the thickness have changed, thus the new insulations are thicker.Moreover, the second and final retrofitting package, introduces an HVAC system, which is a standard system. The aim is to achieve further energy demand reductions and prove that simple and basic changes can improve the quality of living and reduce CO2 emissions.After the completition of the first analysis, a reduction equal to 60 % and after the addition of the HVAC a further 20 % reduction achieved.

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  • 222.
    Arcos Usero, Lucía
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Analysis and improvements of outdoor hot benches in Gävle2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Five exterior hot benches have been installed in Gävle, in Kyrkogatan street by the company Gävle Energi with the aim of achieving the wellnes of people that sit on them. This system uses the residual heat from the district heating, representing consequently a non-polluting system. However, the temperature desired on the surface, 35°C is not always achieved before different exterior conditions. For this reason, Gävle Energi is interested in carrying out a study about enhancements that could be made in the system in order to take them into account for future projects of this kind of technology.

     

    The aim of this project is analysing if it would be possible to achieve the requirements established by Gävle Energi, changing with this objective all the necessary system parameters of the current system such as diameter of the pipes, materials, number of turns... These requirements consist of working with a supply temperature of 40, 45 and 50°C when the exterior conditions are 0, -5 and -10°C respectively, accomplishing always 35°C on the surface. Moreover, in case that it was not possible, providing the company with the characteristics of the system that would make the system as efficient as possible, specifying for different exterior temperatures the mass flow, pressure drop, velocity and needed power.

     

    The study has been developed by different simulations with the software COMSOL, whose use requires a high knowledge on heat transfer. After several simulations, it has been checked that it is not possible to accomplish the requirements established by the company. However, a new more efficient design has been designed because the supply temperatures of the system to accomplish an average temperature of around 35°C on the surface have been minimised. For that, several changes have been carried out. The number of pipes turns have been increased from 12 to 17, their total diameter from 20mm to 30mm and the distance between the centres of the pipes from 5.5cm to 4cm. The 2mm of outer plastic thickness of the pipes has been replaced by copper and the height of the pipes has been moved 2cm upwards.

     

    With all these changes, the final length of the pipes inner the stones has a value of 40.6m and the supply temperatures reach 46, 47 and 49°C for the 0,-5 and -10°C exterior conditions respectively. Apart from the supply temperatures for the study cases, the ones necessary to accomplish always the temperature desired on the surface for other exterior temperatures have been provided together with the amount of power necessary, velocity flow, volumetric flow and pressure drop for all the different cases. These values would allow the company to work always at the optimum point as well as to design the heat pump for the system.

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    Thesis project Lucía Arcos
  • 223.
    Arding, Karin
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    In de Betou, Siri
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences.
    Making grid capacity available through heat pump control2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this report the problem of constructing a bus depot with electrical buses despite the lack of grid capacity, was analyzed. A potential solution is investigated, namely smart control of heat pumps in industries. The possibility of allocating grid capacity to the bus depot by reducing power consumption in heat pumps during peak hours, is taken into consideration. The maximum amount of released capacity in an industrial area is calculated through the controlling of heat pumps. This investigation was made through simulations with a simplified building energy model (lumped capacity model) which was applied to a reference building.

    After mapping the area Boländerna and the geothermal wells located there, IKEA Uppsala was chosen as the reference building, since a third of the total number of wells were found in that area. To take the whole capacity of Boländerna into account, the model was scaled up to estimate the total, possible reduction of power. The bus depot requires 6 MW nighttime and 4 MW daytime, the total amount of electrical power that could be withdrawn, if all heat pumps were on maximum heat, in the chosen area were 0.75 MW and by controlling the heat pumps during an optimized level, the amount of 142 kW could be made available to the electric grid. 142 kW is not enough cover the need for the bus depot but it could supply the need for a slow charger to one of the buses and is therefore a possible sub-solution to the larger problem.

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  • 224.
    Arfan, Muhammad
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Utilization of local bioresources for transport fuels - System analysis for decision support2023Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis presents a comprehensive system analysis of the utilization of biowaste and forest industry residues to produce transportation fuels. It explores various aspects such as the constraints to the production system’s value chain development, the utilization of the geographical proximity of biofuel technology innovation system components, environmental impacts, and economic costs. The primary goal is to establish a knowledge base that can aid regional policymakers and decision-makers in formulating informed policies for the efficient management of local bioresources for transport fuel production. By addressing these aspects, the study seeks to contribute to the wider discourse on efficient local bioresource management and transition to a low-carbon economy. The focused bioresources in this thesis are municipal biowaste and forest industry residues (i.e., sawdust, black liquor, crude tall oil, and fiber waste of the pulp and paper industry). The study focuses on three systems: i) biowaste to biogas for transport, ii) biowaste and sawdust to hydrogen, and iii) forest industry residues to liquid biofuels for transport.

    The biofuel policy instruments in Sweden have proven to be effective in introducing alternative transport fuels, particularly in big cities or urban areas. The results of the biowaste to biogas value chain analysis show that development in the Gävleborg region is stagnated throughout the value chain compared to the national average. This stagnation is mainly attributed to local geodemographic factors. The identified obstacles to development include a lack of regional political agreement regarding the use of biogas as a viable transport fuel, insufficient connectivity and communication among the various regional actors and stakeholders, and a limited understanding among stakeholders of the potential and socio-economic impacts of biogas. 

    The environmental and economic assessment of hydrogen production from biowaste and sawdust is performed from a life cycle perspective, using SimaPro LCA software and CML-IA, 2001 impact assessment method. Economic analysis includes capital and operational expenditures and monetization cost of life cycle environmental impacts. The results show that hydrogen production from biowaste has a higher global warming, photochemical oxidant, and freshwater eutrophication potential than sawdust. Biowaste conversion to hydrogen performs far better in ozone depletion, terrestrial ecotoxicity, abiotic depletion-fossil, abiotic depletion, human toxicity, and freshwater ecotoxicity potential. The fossil energy inputs in biogas and pyrolysis oil reforming, emissions from the digestate treatment, storage, and utilization as bio-fertilizer are the main contributing processes to the overall environmental impacts of biowaste and sawdust conversion to hydrogen. 

    The sensitivity analysis of the LCA results indicates that feedstock to biogas/pyrolysis oil yield ratio and the type of energy source for the reforming process can significantly influence the results, particularly climate change, abiotic depletion, and human toxicity. 

    The life cycle cost (LCC) analysis reveals that the production of hydrogen from biowaste exhibits a lower cost compared to sawdust. This significant cost reduction in the biowaste case can be attributed to lower variable operating expenses (OPEX), primarily due to the price of the biowaste itself. Whereas, in the sawdust case, the feedstock contributes the highest percentage (54%) to the system's OPEX, indicating that variable OPEX is highly sensitive to sawdust prices. Additionally, the capital investment required for the biowaste case was 50% lower, which further contributes to the lower overall LCC compared to the sawdust case.

    The results of forest industry residues to liquid biofuel technology development and the utilization of system components in geographical proximity indicate that geographical proximity can significantly influence the system’s structural growth, trajectory, and development pace. An adapted version of the technological innovation system (TIS) framework was operationalized with the lens of geographical proximity utilization of the system components to the technology development and diffusion. The method of data acquisition involved document analysis and interviews with subsystem actors. The study found that the development of the system is hampered by competition between technologies and low utilization of geographical proximity of the system components, which was partly attributed to a lack of network among subsystem actors and with the national TIS structure. 

    Bioresources in Gävleborg are present in substantial amounts, particularly biowaste from agriculture, the food industry, and households, as well as biomass from the forest industry, which have the potential to be utilized for transport fuel production. However, the evolution of their utilization to power transportation in Gävleborg has been delayed in comparison to several other regions in Sweden. In the case of the technology development of forest industry residue-based transport fuels, the utilization of geographical proximity of artefacts and institutions has played a crucial role. Significant strides have been accomplished in diverse technology domains. However, these advancements have faced obstacles, partially due to the rivalry among system actors aiming to secure a competitive edge in acquiring both knowledge and capital resources and the underutilization of the geographical proximity of actors and industry networks. 

    Based on these research findings, recommendations are provided to support policy and strategy aiming to enhance the utilization of local bioresources for transportation fuels sustainably and cost-effectively with increased local benefits. For example, the study recommends addressing the identified local political, communication, and networking issues, along with integrating regional geodemographic conditions into national biofuel policies and measures. By addressing identified challenges, the Gävleborg region can overcome the stagnation in bioresource to transportation fuel technological systems development and leverage its significant potential.

    This thesis adds valuable insights to the sustainability transition literature about the environment, economy, and the geography of innovation processes. The findings highlight the need for policy interventions to foster collaboration, coordination, and knowledge sharing among stakeholders, as well as support for the development and commercialization of emerging technologies, including forest-based transport fuel technologies. The analysis of cost and environmental impacts of bioresource utilization for hydrogen production provides insights into the potential trade-offs and benefits of different feedstocks and impact categories. The study provides important input for policy and strategy development towards a more sustainable and cost-effective use of local bioresources for transport fuel production in Gävleborg. This study can also serve as a valuable reference for researchers, policymakers, and stakeholders interested in the sustainable utilization of renewable resources for biofuel production, contributing to the advancement of knowledge in this critical area.

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  • 225.
    Arfan, Muhammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Eriksson, Ola
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Wang, Zhao
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Soam, Shveta
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Life cycle assessment and life cycle costing of hydrogen production from biowaste and biomass in Sweden2023In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 291, article id 117262Article in journal (Refereed)
    Abstract [en]

    In this study, an environmental and economic assessment of hydrogen production from biowaste and biomass is performed from a life cycle perspective, with a high degree of primary life cycle inventory data on materials, energy, and investment flows. Using SimaPro LCA software and CML-IA, 2001 impact assessment method, ten environmental impact categories are analyzed for environmental analysis. Economic analysis includes capital and operational expenditures and monetization cost of life cycle environmental impacts. The hydrogen production from biowaste has a high climate impact, photochemical oxidant, and freshwater eutrophication than biomass while it performs far better in ozone depletion, terrestrial ecotoxicity, abiotic depletion-fossil, abiotic depletion, human toxicity, and freshwater ecotoxicity. The sensitivity analysis of LCA results indicates that feedstock to biogas/pyrolysis-oil yields ratio and the type of energy source for the reforming process can significantly influence the results, particularly climate change, abiotic depletion, and human toxicity. The life cycle cost (LCC) of 1 kg hydrogen production has been accounted as 0.45–2.76 € with biowaste and 0.54–3.31 € with biomass over the plant's lifetime of 20 years. From the environmental impacts of climate change, photochemical oxidant, and freshwater eutrophication hydrogen production from biomass is a better option than biowaste while from other included impact categories and LCC perspectives it’s biowaste. This research contributes to bioresources to hydrogen literature with some new findings that can be generalized in Europe and even globally as it is in line with and endorse existing theoretical and simulation software-based studies.

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  • 226.
    Arfan, Muhammad
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    Hillman, Karl
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Environmental Science.
    The geography of technological innovation systems - The case of forest-based biofuels in a Swedish region2024In: Innovation and Green Development, E-ISSN 2949-7531, Vol. 3, no 2, article id 100122Article in journal (Refereed)
    Abstract [en]

    Geographical proximity exerts a substantial influence on structural evolution, developmental trajectory, and pace of sociotechnical system growth. This study explores this aspect within the context of the development of forest biomass-based biofuel technology, employing a Technological Innovation System (TIS) framework with the lens of geographical proximity utilization of system components. The research employed a combination of document analysis and interviews with key system stakeholders as data collection methods. The analysis reveals that the close geographical proximity of the system components and technologies, encompassing both technical aspects and sectors, did not result in synergetic effects, in contrast to prior TIS research findings. Rather than fostering collaboration, it has engendered a competitive dynamic, partially driven by actors vying for knowledge leads and funding from both regional and national agencies. Consequently, the potential benefits of geographical proximity of system components remain largely untapped. In light of these results, this study offers practical recommendations for exploiting untapped opportunities, advocating for more strategic use of geographical proximity to foster system technology development and enhance its role in national TIS development. This case study enriches sustainability transition literature by providing valuable insights into the role of geographical proximity in innovation processes.

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  • 227. Arfvidsson, J.
    et al.
    Bjelke-Holtermann, B.
    Mattsson, J.
    Status determination and risk assessment of measures in historic buildings2018In: Conference Report: The 3rd International Conference on Energy Efficiency in Historic Buildings / [ed] Tor Broström, Lisa Nilsen and Susanna Carlsten, Uppsala University, 2018, p. 345-353Conference paper (Refereed)
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  • 228.
    Arhall, Johanna
    et al.
    Blekinge Institute of Technology, Faculty of Engineering, Department of Industrial Economics.
    Reis, Manuel
    Blekinge Institute of Technology, Faculty of Engineering, Department of Industrial Economics.
    Determinants of Alternative Fuel Technology for Small Road Freight Transport Companies in Sweden2023Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The transportation sector plays a significant role in global carbon emissions, emphasizing the need for transitioning to alternative fuel technologies. This thesis primarily aims to examine the factors that influence small road freight transport companies in Sweden when transitioning to alternative fuel technology. The focus is on identifying these determinants and their respective significance, utilizing a company internal Resource-Based view as the analytical framework. Semi-structured interviews were conducted among small road freight transport companies, with data analyzed using pattern and keyword matching analysis. The results reveal multiple determinants within financial, technological and organizational resources. Range, purchase cost, and customer demand emerged as the most influential determinants, with range limitations hindering adoption and high costs deterring investment. However, customer demand for eco-friendly transport presents an opportunity for companies to gain a competitive advantage. Company size, cargo type, and operational constraints also influence decision-making. In the data selection, micro companies exhibit a higher propensity for drop-in alternative fuels, while small-sized companies engaged in short-haul transportation are more open to alternative fuel adoption and riskier investments. Risk-averse followers tend to stick to established practices. Policymakers are recommended to invest in infrastructure, provide subsidies, and implement regulations to incentivize adoption, while vehicle producers should optimize designs and collaborate with fuel producers. Further research is advised to investigate the viability of different low-carbon fuel alternatives, explore challenges and motivations faced by different company types, and conduct comparative studies. Quantitative research methods can offer broader insights into this area of study.

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    Determinants of Alternative Fuel Technology for Small Road Freight Transport Companies in Sweden
  • 229.
    Arias Hurtado, Jaime
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Applied Thermodynamics and Refrigeration.
    Whole Supermarket System Modelling2015In: Sustainable Retail Refrigeration, Wiley Blackwell , 2015, p. 263-290Chapter in book (Other academic)
    Abstract [en]

    The supermarket sector has more or less used the trial and error approach to implement and evaluate new ideas and concepts for decreasing energy usage and minimizing refrigerant charge. To estimate the energy requirement in a supermarket, it is necessary to evaluate the interrelatedness between the different subsystems and their energy demands. The main subsystems included in computer simulation models for energy use in supermarkets are the building envelope, outdoor climate, HVAC system, refrigeration system and retail display cabinets. The chapter also analyzes four different whole-building simulation models for supermarkets: EnergyPlus developed by the US Department of Energy; CyberMart developed by the Royal Institute of Technology in Sweden; RETScreen developed by Natural Resources Canada; and SuperSim developed by Brunel University in the UK. The implementation of new energy-saving technologies in supermarkets requires an extensive analysis of energy performance of refrigeration systems, HVAC systems, lighting, appliances, and of total energy consumption. 

  • 230.
    Arjmand, Mehdi
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Liu, Longcheng
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Neretnieks, Ivars
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Chemical Engineering.
    Exergetic efficiency of high-temperature-lift chemical heat pump (CHP) based on CaO/CO2 and CaO/H2O working pairs2013In: International Journal of Energy Research, ISSN 0363-907X, E-ISSN 1099-114X, Vol. 37, no 9, p. 1122-1131Article in journal (Refereed)
    Abstract [en]

    The use of reversible chemical reactions in recuperation of heat has gained significant interest due to higher magnitude of reaction heat compared to that of the latent or sensible heat. To implement chemical reactions for upgrading heat, a chemical heat pump (CHP) may be used. A CHP uses a reversible chemical reaction where the forward and the reverse reactions take place at two different temperatures, thus allowing heat to be upgraded or degraded depending on the mode of operation. In this work, an exergetic efficiency model for a CHP operating in the temperature-level amplification mode has been developed. The first law and the exergetic efficiencies are compared for two working pairs, namely, CaO/CO2 and CaO/H2O for high-temperature high-lift CHPs. The exergetic efficiency increases for both working pairs with increase in task, TH, decrease in heat source, TM, and increase in condenser, TL, temperatures. It is also observed that the difference in reaction enthalpies and specific heats of the involving reactants affects the extent of increase or decrease in the exergetic efficiency of the CHP operating for temperature-level amplification.

  • 231.
    Arnaiz Remiro, Lierni
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Modelling and assessment of energy performance with IDA ICE for a 1960's Mid-Sweden multi-family apartment block house2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The present thesis has been carried out during the spring of 2017 on behalf of Gavlegårdarna AB. This is a public housing company in Gävle (Sweden) which is a large energy consumer, over 200 million SEK per year, and has the ambitious goal of reduce its energy consumption by 20 % between 2009 and 2020. Many multi-family apartment blocks were built during the "million programme" in the 60’s and 70’s when thermal comfort was the priority and not the energy saving. Nevertheless, this perspective has changed and old buildings from that time have been retrofitted lately, but there are many left still. In fact, one of these buildings will be retrofitted in the near future so a valid model is needed to study the energy saving measures to be taken. The aim of this thesis is to get through a calibration process to obtain a reliable and valid model in the building simulation program IDA ICE 4.7.1. Once this has been achieved it will be possible to carry out the building’s energy performance assessment. IDA ICE has shown some limitations in terms of thermal bridges which has accounted for almost 15 % of total transmission heat losses. For this reason, it is important to make a detailed evaluation of certain joints between elements for which heat losses are abundant. COMSOL Multiphysics® finite element software has been used to calculate these transmittances and then use them as input to IDA ICE to carry out the simulation.

    Through an evidence-based methodology, although with some sources of uncertainty, such as, occupants’ behaviour and air infiltration, a valid model has been obtained getting almost the same energy use for space heating than actual consumption with an error of 4% (Once the standard value of 4 kWh/m2 for the estimation of energy use in apartments' airing has been added). The following two values have been introduced to IDA ICE: household electricity and the energy required for heating the measured volume of tap water from 5 °C to 55 °C. Assuming a 16 % of heat losses in the domestic hot water circuit, which means that part of the heat coming from hot water heats up the building. This results in a lower energy supply for heating than the demanded value from IDA ICE. Main heat losses have been through transmission and infiltration or openings. Windows account 11.4 % of the building's envelope, thus the losses through the windows has supposed more than 50 % of the total transmission losses. Regarding thermal comfort, the simulation shows an average Predicted Percentage of Dissatisfied (PPD) of 12 % in the worst apartment. However, the actual value could be considerably lower since the act of airing the apartments has not been taken into account in the simulation as well as the strong sun's irradiation in summer which can be avoided by windows shading. So, it could be considered an acceptable level of discomfort. To meet the National Board of Housing Building and Planning, (Boverket) requirements for new or rehabilitated buildings, several measures should be taken to improve the average thermal transmittance and reduce the specific energy use. Among the energy saving measures it might be interesting replace the windows to 3 pane glazing, improve the ventilation system to heat recovery unit, seal the joints and intersections where thermal bridges might be or add more insulation in the building’s envelope.

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  • 232.
    Arnal Estelles, Paloma
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Hand drying in public places: Paper towel vs warm air blower, which is best from an energy and environmental point of view.2023Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
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  • 233.
    Arnaudo, Monica
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Topel, Monika
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Laumert, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Vehicle-to-grid for peak shaving to unlock the integration of distributed heat pumps in a swedish neighborhood2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 7, article id en13071705Article in journal (Refereed)
    Abstract [en]

    The city of Stockholm is close to hitting the capacity limits of its power grid. As an additional challenge, electricity has been identified as a key resource to help the city to meet its environmental targets. This has pushed citizens to prefer power-based technologies, like heat pumps and electric vehicles, thus endangering the stability of the grid. The focus of this paper is on the district of Hammarby Sjöstad. Here, plans are set to switch from district heating to heat pumps. A previous study verified that this choice will cause overloadings on the electricity distribution grid. The present paper tackles this problem by proposing a new energy storage option. By considering the increasing share of electric vehicles, the potential of using the electricity stored in their batteries to support the grid is explored through technical performance simulations. The objective was to enable a bi-directional flow and use the electric vehicles' (EVs)' discharging to shave the peak demand caused by the heat pumps. It was found that this solution can eliminate overloadings up to 50%, with a 100% EV penetration. To overcome the mismatch between the availability of EVs and the overloadings' occurrence, the minimum state of charge for discharging should be lower than 70%.

  • 234.
    Arnaudo, Monica
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Topel, Monika
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Puerto, P.
    CREM Centre de Recherches Énergétiques et Municipales, Martigny, Switzerland. HES-SO Haute École Spécialisée de Suisse Occidentale, Sion, Switzerland.
    Widl, E.
    AIT Austrian Institute of Technology, Center for Energy, Vienna, Austria.
    Laumert, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Heat demand peak shaving in urban integrated energy systems by demand side management - A techno-economic and environmental approach2019In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 186, article id 115887Article in journal (Refereed)
    Abstract [en]

    The integration of variable renewable resources and decentralized energy technologies generates the need for a larger flexibility of the energy demand. In order to fully deploy a demand side management approach, synergies between interconnected energy systems have to be systematically implemented. By taking this standpoint, this study proposes a new approach to explore the potential of multi-energy integrated energy systems. This approach is constituted by two main steps, which are (1) the performance simulation of selected energy infrastructures and (2) the estimation of related techno-economic performance indicators. Step (1) expands the work presented in previous literature, by including a novel co-simulation feature. In step (2), the levelized cost of energy and location-dependent emission factors are used as key performance indicators. In this paper, the presented approach is demonstrated by implementing two demand side management options for heat peak demand shaving. A Swedish residential neighborhood is considered as a case study. The first option explores the potential of storing heat in the thermal mass of residential buildings. The proposed strategies lead to a decrease of up to 70% of primary energy consumption, depending on the indoor comfort requirements. The second option estimates the techno-economic feasibility of a new set of scenarios based on the integration of geothermal distributed heat pumps within a district heating network. The district heating scenario is found to be the most techno-economical convenient. Nevertheless, a moderate penetration of distributed heat pumps (around 20%) is shown to have a good trade-off with the reduction of CO2 emissions.

  • 235.
    Arnaudo, Monica
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Zaalouk, O. A.
    Topel, Monika
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Laumert, Björn
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Techno-economic Analysis of Integrated Energy Systems at Urban District Level - A Swedish Case Study2018In: Energy Procedia, Elsevier, 2018, p. 286-296Conference paper (Refereed)
    Abstract [en]

    Within the Nordic countries, distributed heat and power supply technologies, like domestic scale heat pumps and photovoltaics, are challenging the current centralized district energy infrastructure. An increasing number of customers decide to disconnect from the traditional heating network by comparing the bill to the potential economic savings which can be generated by a residential heat pump system. However, this approach can be considered valid only on a short-term perspective. This paper presents a new approach to compare the techno-economic performance of alternative technologies, based on their lifetime average cost of generation. The proposed analysis is able to determine the optimal energy infrastructure at urban district level. Within this solution, operators, city planners and users will have a solid reference for their decision making process on resources investment. From a first step analysis of a few Swedish case studies, it was found that a district heating based system is more techno-economically efficient compared to the distributed alternative. By comparing the district heating production cost to its final price, a significant profit margin for the utility was qualitatively highlighted. Thus, from a customer perspective, on the medium run, the district heating tariff can be adapted and the estimated savings from switching to a residential heat pump system can be nullified.

  • 236.
    Arrese Foruria, Ander
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Analysis of a Low Energy Building with District Heating and Higher Energy Use than Expected2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In this thesis project, a building in Vegagatan 12, Gävle has been analysed. The main objective has been to find why it consumes more energy than it was expected and to solve theoretically the problems.This building is a low energy building certified by Miljöbyggnad which should use less than 55kWh/m2 year and nowadays it is using 62.23 kWh/m2. In order to find why the building is using more energy than the expected several different things has been measured and analyzed.First of all, the heat exchanger of the ventilation unit has been theoretically examined to see if it works as it should and it does. This has been done using the definition of the heat exchangers.Secondly, the heating system has been analysed by measuring the internal temperature of the building and high temperatures have been found (around 22°C) in the apartments and in the corridors. This leads to 5-10% more use of energy per degree.Thirdly, the position and the necessity of all the heaters have been checked. One of the heaters may not make sense, at least in the way the building has been constructed. This leads to bigger heating needs than the expected.Fourthly, the taps and shower heads have been checked to see if they were efficient. Efficient taps and shower heads, reduce the hot water use up to 40%. The result of this analysis has been that all taps and shower heads are efficient.Fifthly, the hot water system has been studied and some heat losses have been found because the lack of insulation of several pipes. Because of this fact 8.37kWh/m2 are lost per year. This analysis has been carried out with the help of an infra red camera and a TA SCOPE.Sixthly, the theoretical and real U values of the different walls have been obtained and compared (concrete and brick walls). As a conclusion, the concrete wall has been well constructed but, the brick wall has not been well constructed. Because of this fact 1 kWh/m2 of heat are lost every year. Apart from that, windows and thermal bridges have also been checked.

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  • 237.
    Arteaga Ossa, Andres
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    Evaluating the onshore wind power potential of Gotland using the New European Wind Atlas2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The island of Gotland has played an important role in the history of wind energy in Sweden since the very beginning. In the past decade, the island reached the maximum intermittent wind power capacity that the local grid and the current connection to the mainland can safely manage without compromising the security of supply. There were plans to install a new submarine cable, but they were finally cancelled. Nevertheless, the Swedish Government has decided to start a pilot project to make Gotland the spearhead of the energy transition. Most likely, this means that a new wind power expansion will have to take place on the island. In that context, the present study aims to estimate the onshore wind power potential of Gotland based on the New European Wind Atlas released in 2019. The starting assumption is that the potential of the island is limited to the areas appointed of national interest for wind energy by the Swedish Energy Agency. Then, the wind power potential is estimated under three technological scenarios ranging from the wind turbines operating on the island to the wind turbines recently launched on the global market. The results show that Gotland has the potential to annually produce between 2.2 TWh and 2.7 TWh of additional energy from the available wind depending on the technology used. Comparisons with real production records showed that the wind speed time series from the wind atlas proved to be useful to accurately reproduce the production patterns of real wind turbines on the island when values were aggregated at a daily or higher time scale. Additionally, mean wind speed at 100 m and the parameters of the Weibull functions fitted to the wind speed distributions were mapped for the whole island. Mean wind speeds obtained from the New European Wind Atlas for the areas of national interest on Gotland were compared to the respective values from the Swedish Wind Atlas. It was found that the latter gives systematically higher values with an average difference of 0.4 m/s within the sample.

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    MScThesisWPPM2021_AndresArteaga
  • 238. Artigas, D.
    et al.
    O’Brien, S.
    Aijazi, A.
    An unfair reputation: The energy performance of mid-century metal-and-glass curtain walls2018In: Conference Report: The 3rd International Conference on Energy Efficiency in Historic Buildings / [ed] Tor Broström, Lisa Nilsen and Susanna Carlsten, Uppsala University, 2018, p. 391-400Conference paper (Refereed)
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  • 239.
    Arumägi, Endrik
    et al.
    Chair of Building Physics and Architecture, Tallinn University of Technology, Estonia.
    Kalamees, Targo
    Chair of Building Physics and Architecture, Tallinn University of Technology, Estonia.
    Broström, Tor
    Gotland University, School of Culture, Energy and Environment.
    Indoor climate in a naturally ventilated unheated medieval church in Harju-Risti, Estonia2010In: 10th REHVA World congress Clima 2010: Sustainable Energy Use in Buildings, 2010Conference paper (Refereed)
    Abstract [en]

    Indoor climate in a naturally ventilated unheated medieval church was analysed to determine if the conditions existing suit for three medieval wooden sculptures forming the Calvary group that were decorated the church until 1958. The values of temperature and RH were measured with data loggers at 1-h intervals inside and outside the church. Ventilation measurements were performed using a passive tracer gas technique. The current study shows that there is a considerable risk in bringing back the medieval sculptures forming the Calvary group to the Harju-Risti Church without creating conditions for indoor temperature and humidity regulation. To start risk assessment it is required to maintain a RH level that prevents the risk of mould growth, reduce fluctuations of air RH annually and in the short term period, avoid of too high and too low humidity levels in church that could cause flaking, peeling and cracking of wooden sculptures.

  • 240.
    Arvanitis, Konstantinos
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    MACROALGAE IN THE BIOREFINERY: A SUBSTANCE FLOW ANALYSIS AND ENVIRONMENTAL ASSESSMENT OF AN EXTRACTION PROCESS OF THE MAJOR COMPONENTS IN SACCHARINA LATISSIMA2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A turn to more sustainable resources has lead the research during the last decades to algae. Algae is a resource that has been utilized for thousands of years offering a variety of possibilities. Nevertheless modern technology were able to uncover algae’s great potential and pave the way for alternative uses such as biofuel and biomaterial production. Towards that direction, ‘Seafarm’ aims in utilizing algae in the most efficient and sustainable way. For that purpose various steps have been established, including the biorefinery step which entail among other the extraction of carbohydrates from brown algae.

    The current thesis is based on an extraction of carbohydrates from Saccharina latissima, a brown algae species, which was developed by Viktor Öberg during his master thesis at KTH. The aim of this work is to assist in the scaling up of that laboratory process by analyzing the basic steps and substances of the process, investigating its environmental performance and identifying improvement areas for theoretical optimization. The results of the aforementioned analysis include a substance flow analysis which reveals the basic steps of the process and constitute the basis for further analysis. The second step examines the environmental performance of the process based on the chemical selection. Hence the results are a risk assessment of chemicals with performance indicators for each chemical as well as the whole process. The final part provides a theoretical optimization of the process based on literature studies where the recommendations are divided in production optimization and environmental performance.

    The above results constitute the basis of the analysis of the process and sets the foundations for scaling up the process at an industrial level. The current analysis in combination with an energy and economic assessment could be used for the designing of the process and its integration in the biorefinery. 

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  • 241.
    Arvidsson, Mari
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Electricity.
    Analys av mellanspänningsnätet i centrala delar av Västerås stad2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The dependency of continuous electricity supply is high in the Swedish society today, at the same time no one is willing to pay for a too costly or over dimensioned power distribution system. The owners of the distribution systems are the ones responsible for this balance act of maintaining a high quality of electricity delivery to customers at a reasonable cost.

    In this master thesis a limited part of the primary distribution system (10 kV), owned by Mälarenergi Elnät AB and located in the city centre of Västerås, was chosen for a deeper analysis of its reliability. Its ability to handle outages of system components (N-1 and N-2 contingency analysis) was investigated to find out potential weak spots and parts of the grid that showed signs of being overdimensioned.

    The results of the performed simulations showed that in 74 % of the studied N-1 contingencies cases, consisting of outages of a bus bar in a distribution substation, the system could handle this without causing outages in other parts of the grid. For the N-2 contingencies 61 % passed the test. It was also found that one of the two included high voltage substations could alone supply the investigated part of the grid. Some cables and transformers were found to be more or less unnecessary, whereas other components proved to be overloaded in several situations.

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  • 242.
    Aryal, Um Kanta
    et al.
    Mads Clausen Institute, Center for Advanced Photovoltaics and Thin Film Energy Devices (SDU CAPE), University of Southern Denmark, Sønderborg 6400, Denmark; SDU Climate Cluster, University of Southern Denmark, Odense 5230, Denmark.
    Pazniak, Hanna
    Université Grenoble Alpes, CNRS, Grenoble INP, LMGP, Grenoble, CS 50257, Grenoble Cedex 1 38016, France.
    Kumari, Tanya
    Mads Clausen Institute, Center for Advanced Photovoltaics and Thin Film Energy Devices (SDU CAPE), University of Southern Denmark, Sønderborg 6400, Denmark; SDU Climate Cluster, University of Southern Denmark, Odense 5230, Denmark.
    Weber, Matthieu
    Université Grenoble Alpes, CNRS, Grenoble INP, LMGP, Grenoble, CS 50257, Grenoble Cedex 1 38016, France.
    Johansson, Fredrik
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Chemistry, Applied Physical Chemistry. Institut des Nanosciences de Paris, Sorbonne Universite, UMR CNRS 7588, F-75005 Paris, France.
    Vannucchi, Noemi
    Institut des Nanosciences de Paris, Sorbonne Universite, UMR CNRS 7588, F-75005 Paris, France; Division of X-ray Photon Science, Department of Physics and Astronomy, Uppsala University, Box 516, 751 20 Uppsala, Sweden.
    Witkowski, Nadine
    Institut des Nanosciences de Paris, Sorbonne Universite, UMR CNRS 7588, F-75005 Paris, France.
    Turkovic, Vida
    Mads Clausen Institute, Center for Advanced Photovoltaics and Thin Film Energy Devices (SDU CAPE), University of Southern Denmark, Sønderborg 6400, Denmark; SDU Climate Cluster, University of Southern Denmark, Odense 5230, Denmark.
    Di Carlo, Aldo
    Istituto di Struttura della Materia, CNR-ISM, Via del Fosso del Cavaliere 100, Rome 00133, Italy, Via del Fosso del Cavaliere 100; CHOSE (Centre for Hybrid and Organic Solar Energy), Department of Electronic Engineering, University of Rome “Tor Vergata”, via del Politecnico 1, Rome 00133, Italy, via del Politecnico 1.
    Madsen, Morten
    Mads Clausen Institute, Center for Advanced Photovoltaics and Thin Film Energy Devices (SDU CAPE), University of Southern Denmark, Sønderborg 6400, Denmark; SDU Climate Cluster, University of Southern Denmark, Odense 5230, Denmark.
    2D MXene-Based Electron Transport Layers for Nonhalogenated Solvent-Processed Stable Organic Solar Cells2023In: ACS Applied Energy Materials, E-ISSN 2574-0962, Vol. 6, no 9, p. 4549-4558Article in journal (Refereed)
    Abstract [en]

    Implementation of 2D materials is one of the promising routes for improving the efficiency and stability of organic solar cells (OSCs). Due to their tunable optical and electronic properties, MXenes, a family of 2D transition metal carbides and nitrides, have attracted considerable attention and demonstrated their potential for next-generation solar cells. In this work, Ti3C2Tx MXene was added into ZnO precursors and applied as a modified composite electron transport layer (ETL) in PM6:N3-based inverted OSCs. The nonhalogenated solvent o-xylene was employed as the active layer solvent for the development of stable, efficient, and eco-friendly OSCs. By optimizing the concentration of Ti3C2Tx in the ZnO ETL, the solar cells exhibited power conversion efficiencies (PCEs) of 14.1 and 13.7% for 0.5 and 2 wt % MXene, respectively, as compared to neat ZnO layer devices with a PCE of 14.9%. Interestingly, the MXene-based PM6:N3 OSC devices showed superior device stability compared to the reference cells. It is demonstrated that the MXene introduced in the composite ZnO-based ETL mitigates the photocatalytic decomposition of the organic active layer on the ZnO surface, as analyzed via optical spectroscopy and hard X-ray photoelectron spectroscopy, which appears as a main reason for improved device stability. We thus report on the usage of MXene in green solvent-processed OSCs to enhance the lifetime of solar cells and thus address an important bottleneck in high-performance nonfullerene acceptor solar cells.

  • 243.
    Asef, Pedram
    et al.
    Univ Politecn Cataluna, BarcelonaTech, Dept Elect Engn, EEBE, Barcelona 08019, Spain..
    Bargallo Perpina, Ramon
    Univ Politecn Cataluna, BarcelonaTech, Dept Elect Engn, EEBE, Barcelona 08019, Spain..
    Barzegaran, M. R.
    Lamar Univ, Renewable Energy Microgrid Lab, Beaumont, TX 77705 USA..
    Lapthorn, Andrew
    Univ Canterbury, Dept Elect & Comp Engn, Christchurch 8041, New Zealand..
    Mewes, Daniela
    KTH, School of Industrial Engineering and Management (ITM).
    Multiobjective Design Optimization Using Dual-Level Response Surface Methodology and Booth's Algorithm for Permanent Magnet Synchronous Generators2018In: IEEE transactions on energy conversion, ISSN 0885-8969, E-ISSN 1558-0059, Vol. 33, no 2, p. 652-659Article in journal (Refereed)
    Abstract [en]

    This paper studies a dual-level response surface methodology (DRSM) coupled with Booth's algorithm using a simulated annealing (BA-SA) method as a multiobjective technique for parametric modeling and machine design optimization for the first time. The aim of the research is for power maximization and cost of manufacture minimization resulting in a highly optimized wind generator to improve small power generation performance. The DRSM is employed to determine the best set of design parameters for power maximization in a surface-mounted permanent magnet synchronous generator with an exterior-rotor topology. Additionally, the BA-SA method is investigated to minimize material cost while keeping the volume constant. DRSM by different design functions including mixed resolution robust design, full factorial design, central composite design, and box-behnken design are applied to optimize the power performance resulting in very small errors. An analysis of the variance via multilevel RSM plots is used to check the adequacy of fit in the design region and determines the parameter settings to manufacture a high-quality wind generator. The analytical and numerical calculations have been experimentally verified and have successfully validated the theoretical and multiobjective optimization design methods presented.

  • 244.
    Aslani, Mohammad
    et al.
    Univ Gävle, Dept Comp & Geospatial Sci, Gävle, Sweden..
    Seipel, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Computerized Image Analysis and Human-Computer Interaction. Univ Gävle, Dept Comp & Geospatial Sci, Gävle, Sweden..
    A Spatially Detailed Approach to the Assessment of Rooftop Solar Energy Potential based on LiDAR Data2022In: GISTAM: Proceedings of the 8th International Conference on Geographical Information Systems Theory, Applications and Management / [ed] Cédric Grueau, Lemonia Ragia, Setúbal: SciTePress, 2022, p. 56-63Conference paper (Refereed)
    Abstract [en]

    Rooftop solar energy has long been regarded as a promising solution to cities' growing energy demand and environmental problems. A reliable estimate of rooftop solar energy facilitates the deployment of photovoltaics and helps formulate renewable-related policies. This reliable estimate underpins the necessity of accurately pinpointing the areas utilizable for mounting photovoltaics. The size, shape, and superstructures of rooftops as well as shadow effects are the important factors that have a considerable impact on utilizable areas. In this study, the utilizable areas and solar energy potential of rooftops are estimated by considering the mentioned factors using a three-step methodology. The first step involves training PointNet++, a deep network for object detection in point clouds, to recognize rooftops in LiDAR data. Second, planar segments of rooftops are extracted using clustering. Finally, areas that receive sufficient solar irradiation, have an appropriate size, and fulfill photovoltaic installation requirements are identified using morphological operations and predefined thresholds. The obtained results show high accuracy for rooftop extraction (93%) and plane segmentation (99%). Moreover. the spatially detailed analysis indicates that 17% of rooftop areas are usable for photovoltaics.

  • 245.
    A.S.M. Monjurul, Hasan
    et al.
    Department of Electrical and Electronic Engineering, Bangladesh Army International University of Science and Technology, Cumilla, Bangladesh.
    Ammenberg, Jonas
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Biogas potential from municipal and agricultural residual biomass for power generation in Hazaribagh, Bangladesh: A strategy to improve the energy system2019In: Renewable Energy Focus, ISSN 1755-0084, Vol. 29, no June 2019, p. 14-23Article in journal (Refereed)
    Abstract [en]

    Energy is considered as one of the significant benchmarks towards sustainable growth. Due to the recenteconomic growth, energy demand is increasing day by day in Bangladesh. The power generation mainlyrelies on fossil fuels though there are plans to increase the renewable energy share by the concernstakeholders. Considering the global warming, energy generation from renewable sources is consideredas a sustainable way to mitigate the anthropogenic emission. This study, therefore, addresses thepotentiality of biogas production from municipal waste and agricultural residues in a city territory ofDhaka namely Hazaribagh. The potential sources include wastes from two markets, six slaughterhouses,domestic wastes, one poultry farm and three croplands. The calculations made in this study to estimatethe amount of biogas and electricity from the described sources are done in a simple way, just to illustratethe potential. This study suggests that there is a good potentiality of biogas production and electricitygeneration from municipal wastes and agricultural residues of Hazaribagh. Moreover, this study alsomentions the significant actors like government, future owners, people and so on that are needed to beincorporated to implement biogas solution in a city territory.

  • 246.
    Ast, Eric
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering, Industrial Ecology.
    The state of long-term climate action planning in megacities: Planning and demographic trends among 17 of the world’s leading cities aiming to reduce emissions by 80% by the year 20502015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This report reviews the current state of long-term climate action planning in 17 cities which have publicly communicated carbon reducttargets in line with the IPCC recommended 80% reduction by 2050 (80x50) for stabilizing the impacts of climate change at 2°C.  The aim of this report is to provide a foundation of support for cities in achieving their deep carbon reduction goals through a comprehensive understanding of leading climate action plans and the context under which they were created, including current city emissions and demographic data, climate plan reduction strategies and targets, and feedback on plan creation and needs from city planning staff.  By achieving this aim, cities are in a better position to understand where their plans fit in the global context and connect with other cities around common issues, research institutions have a new benchmark analysis of leading action plans to build further research upon, and city-level climate action organizations have a clearer idea of how to focus efforts in helping cities achieve carbon reduction goals.  This aim is achieved through the application of a framework for comparing city plans and targets, an analysis of current city emissions and demographic data, and synthesis of key findings from city planning staff discussions.  

    Key findings show no clear demographic and environmental biases exist within these 17 cities, indicating long-term climate action planning can be undertaken by cities across the full spectrum of size, climate, and current per capita emissions output, though regional geographic and development bias exists.  Plans for carbon reduction are highly concentrated among a small number of actions, indicating the movement has coalesced around a standard set of strategies for achieving deep carbon reductions.  Finally, the relative newness of plans, with the majority less than 5 years old, and the lack of commonality among cities in emissions methodology and communication of reduction strategies, shifts a short-term focus towards standardization methodologies which enable deeper comparison between cities and plans.

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  • 247. Asthana, Arvind
    et al.
    Nair, Gireesh
    ?.
    Big efficiency in small scale2001Other (Other (popular science, discussion, etc.))
  • 248. Asthana, Arvind
    et al.
    Nair, Gireesh
    Big efficiency in small scale2001Other (Other (popular science, discussion, etc.))
  • 249.
    Atabaki, Mohammad Saeid
    et al.
    Halmstad University, School of Business, Innovation and Sustainability. Kharazmi University, Tehran, Iran.
    Bagheri, Mehdi
    University of Victoria, Victoria, Canada.
    Aryanpur, Vahid
    University College Cork, Cork, Ireland.
    Exploring the role of electrification and modal shift in decarbonizing the road passenger transport in British Columbia2023In: Sustainable Energy Technologies and Assessments, ISSN 2213-1388, E-ISSN 2213-1396, Vol. 56, article id 103070Article in journal (Refereed)
    Abstract [en]

    The possibility of the modal shift to public transport and active mobility while considering transport electrification and fuel efficiency improvement has yet to be adequately investigated. This paper explores transition pathways toward an environmentally sustainable road passenger transportation system in the province of British Columbia (BC), Canada. MESSAGE, as a bottom-up energy systems optimization model, is used to find the cost-optimal fuel and technology mix in the transport and power sector. Multiple scenarios mainly assess the influence of modal shift and electric vehicle (EV) diffusion on greenhouse gas emissions by 2050. Besides, the effects of scenarios on the power sector configuration are examined. The results show that BC would not achieve the 80% emissions reduction target in the Climate Change Accountability Act unless by a radical expansion of transport electrification. The target could be met by a minimum diffusion of 70% EVs in the total car stock as well as 35% public transport contribution in total passenger kilometers. The findings also indicate that fully electrified light-duty vehicles coupled with active transport would lead to almost a zero-emission level. Nevertheless, 100% electrification would impose an extra 5.6 TWh burden on the power supply system relative to the business-as-usual scenario. © 2023 The Authors. Published by Elsevier Ltd

  • 250.
    Atif, Yacine
    et al.
    Högskolan i Skövde, Institutionen för informationsteknologi.
    Ding, Jianguo
    Högskolan i Skövde, Institutionen för informationsteknologi.
    Lindström, Birgitta
    Högskolan i Skövde, Institutionen för informationsteknologi.
    Jeusfeld, Manfred
    Högskolan i Skövde, Institutionen för informationsteknologi.
    Andler, Sten F.
    Högskolan i Skövde, Institutionen för informationsteknologi.
    Yuning, Jiang
    Högskolan i Skövde, Institutionen för informationsteknologi.
    Brax, Christoffer
    CombiTech AB, Skövde, Sweden.
    Gustavsson, Per M.
    CombiTech AB, Skövde, Sweden.
    Cyber-Threat Intelligence Architecture for Smart-Grid Critical Infrastructures Protection2017Conference paper (Refereed)
    Abstract [en]

    Critical infrastructures (CIs) are becoming increasingly sophisticated with embedded cyber-physical systems (CPSs) that provide managerial automation and autonomic controls. Yet these advances expose CI components to new cyber-threats, leading to a chain of dysfunctionalities with catastrophic socio-economical implications. We propose a comprehensive architectural model to support the development of incident management tools that provide situation-awareness and cyber-threats intelligence for CI protection, with a special focus on smart-grid CI. The goal is to unleash forensic data from CPS-based CIs to perform some predictive analytics. In doing so, we use some AI (Artificial Intelligence) paradigms for both data collection, threat detection, and cascade-effects prediction. 

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