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  • 1.
    Abadie, Brendan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energi och klimatstudier, ECS.
    Power investment outlook for Chile to 20402020Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This study aims to build a medium-term (2019-2040) model for the Chilean electricity generation system in the OSeMOSYS software, a linear cost optimisation model, in light of the most recent developments in government policy and targets. In 2019, the Chilean government committed to decommissioning all coal plants by 2040 at the latest, and set out a non-binding target to be carbon neutral by 2050. The carbon neutrality target could be enshrined in the climate change law, which has yet to be ratified. In this thesis, a focus was put on the upfront capital cost of the system, and the emissions attributable to Chile’s GHG Inventory (called the SNI GHG in Chile) from operating the system. Three scenarios are developed within the thesis, in line with three paths the power system may follow: a BAU scenario including current power purchase agreements, a scenario in which power purchase agreements for fossil fuels are bought out and the free market then takes over, and a non-conventional renewable energy (NCRE) scenario in which certain renewable technologies account for 68% of production in 2040. The model is validated against the results from 2019 and a broadly similar model developed in the private sector. Sensitivity analysis scenarios were conducted for the input parameters: price of natural gas, price of coal, capital cost of solar PV, capital cost of wind, capital cost of wind & solar, and the capacity factor of hydropower. The sensitivity analyses show the most sensitive input parameters are the price of natural gas and capital cost of wind with respect to the outputs of capital cost, NCRE production ratio such as the share of all solar, wind, and certain hydro technologies as a percentage of total electricity production and GHG emissions.

    Fulltekst (pdf)
    fulltext
  • 2.
    Abbott, Michele
    et al.
    RAND Corp, Pardee RAND Grad Sch, Santa Monica, CA 90406 USA..
    Bazilian, Morgan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik. Columbia Univ, Swedish Royal Inst Technol, Ctr Global Energy Policy, New York, NY 10027 USA..
    Egel, Daniel
    RAND Corp, Santa Monica, CA 90406 USA..
    Willis, Henry H.
    RAND Corp, Santa Monica, CA 90406 USA..
    Examining the food-energy-water and conflict nexus2017Inngår i: Current Opinion in Chemical Engineering, E-ISSN 2211-3398, Vol. 18, s. 55-60Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    There is growing evidence of a strong linkage or 'nexus' between conflict - both domestic and international - and food, energy, and water (FEW) resources and services. This article demonstrates a positive, significant correlation between two measures, FEW security and political stability, and reviews the evidence for how each of these three types of resource insecurities affects political and social stability. We describe what is known about the FEW-conflict nexus itself, note that remaining knowledge gaps include evidence on developing governance structures and preparing for climate change, and examine the types of policies that countries and international donors might take to help mitigate the role that FEW can play in affecting stability.

  • 3.
    Abdi, Amir
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Chiu, Justin NingWei
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Martin, Viktoria
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi. KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    State of the art in hydrogen liquefaction2020Inngår i: Proceedings of the ISES Solar World Congress 2019 and IEA SHC International Conference on Solar Heating and Cooling for Buildings and Industry 2019, International Solar Energy Society , 2020, s. 1311-1320Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Hydrogen is a potential option to replace fossil fuels considering the increasing demand of energy applications. It is naturally abundant and is regarded as a suitable energy carrier. There has been extensive research to improve the efficiency of storing hydrogen with different methods, including gas compression, liquefaction and sorption in metal hydrides or carbon nanotubes. A comparison of the storage methods shows that liquefaction of hydrogen is more beneficial than compression of hydrogen in terms of higher volumetric capacity, and it is more technologically mature than sorption technologies. This makes it more plausible for long distance distribution. On the other hand, the obstacles in full exploitation of the method are low energy efficiency of the liquefaction process and associated high cost. The recent research has been focusing on increasing the energy efficiency of the storage process. This paper provides, with regard to the conventional methods, a state of the art review of the novel and modified liquefaction process and the latest developments in increasing the efficiency of the energy intensive process. Furthermore, the developments in combining the hydrogen liquefaction plants with renewable energy sources are covered and reviewed. Finally, the ongoing development of hydrogen liquefaction is highlighted.

  • 4.
    Abid, Hamza
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Techno-economic analysis of energy storage integration for solar PV in Burkina Faso2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Electrification in rural areas of West African countries remain to be a challenge for the growth of the region. The Economic Community of West African States (ECOWAS) has set a target of 2030 to achieve 100% electrification in all member countries. Burkina Faso is one of the least electrified countries in the world, where only 9 % of the rural population has access to electricity. This study presents a conceptualization of techno-economic feasibility of pumped hydro storage (PHS) and electric batteries with solar photovoltaics (PV) in the context of Burkina Faso. The results are explored for an off grid standalone PV plus storage system for a rural setting and a grid connected PV system for an urban setup. The least cost configurations for both the cases are determined using HOMER (Hybrid Optimization Model for Electric Renewables). The results indicate the need of extended solar penetration in Burkina Faso in response to the challenges of low electrification rates in the country. Adding more PV to the present electricity mix of Burkina Faso could drive down the cost of energy by 50 % compared to the present grid electricity prices by making cheap electricity available to the local population. Adding PHS to grid connected PV leads to a cost reduction of 8% over a lifetime of 25 years which does not provide enough motivation for the high investments in storage at present. Policy interventions that allow stacking up of revenues and benefits of storage are needed to make it more competitive. PV plus pumped hydro storage remains the optimal system architecture as compared to PV plus electric batteries for off grid standalone systems provided the geographic availability of lower and upper reservoirs. The capital cost of PV remains to be the most dominating factor in the cost of optimal system for both the urban and the rural cases, and driving down the costs of PV would have the most positive effect for increased electricity access in the country.

    Fulltekst (pdf)
    fulltext
  • 5.
    Abid, Hamza
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Thakur, Jagruti
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystem.
    Khatiwada, Dilip
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Bauner, David
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.), Hållbarhet, Industriell dynamik & entreprenörskap. Renetech AB, Sweden.
    Energy storage integration with solar PV for increased electricity access: A case study of Burkina Faso2021Inngår i: Energy, E-ISSN 0360-5442, Vol. 230, nr 120656, s. 120656-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Electricity access remains a challenge for the majority of the West African countries, wherein 5 out of 16 have an electrification rate of less than 25%, with Burkina Faso having only 9% of the rural population with electricity access in 2017. This study presents a techno-economic feasibility analysis of solar PV system integration with conceptualized Pumped Hydro Storage (PHS) and electric batteries for Burkina Faso. The study explores two cases (a) an off-grid PV with a storage system for rural areas and (b) a grid-connected PV system for an urban location. The least-cost configuration of PV with feasible storage is investigated using HOMER. The results show that Solar PV with PHS remains the optimal system configuration for both rural and urban cases even when the construction costs of lower and upper reservoirs are considered. Battery energy storage systems remain an economically expensive solution even when the added costs of pumped hydro storage are included, owing to the low lifetime and high capital costs of battery storage. The capital cost of PV remains to be the most dominating factor for both cases, signifying the importance of policy interventions for cost reduction of PV for increased green electrification in West African countries.

  • 6.
    Ackermann, Thomas
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Historical Development and Current Status of Wind Power2012Inngår i: Wind Power in Power Systems, Second Edition, John Wiley & Sons, 2012, s. 21-24Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The chapter provides an overview of the historical development (mechanical and electrical power generation) of wind power. It also present the current status of wind power world-wide (capacity installed) together with a discussion of the main drivers for the wind power development, e.g. feed-in tariffs, green certificates etc. Furthermore, the chapter briefly discuss the current trends in wind turbine technology, e.g. larger turbines, and projects development, e.g. offshore wind power.

  • 7.
    Ackermann, Thomas
    KTH. Energynautics GmbH, Germany; Technical University in Darmstadt (TUD), Germany..
    Introduction2012Inngår i: Wind Power in Power Systems, Second Edition, Wiley , 2012, s. 1-5Kapittel i bok, del av antologi (Fagfellevurdert)
  • 8.
    Ackermann, Thomas
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Wind Power in Power Systems2005Bok (Annet vitenskapelig)
    Abstract [en]

    As environmental concerns have focussed attention on the generation of electricity from clean and renewable sources, wind energy has become the world's fastest growing energy source. The authors draw on substantial practical experience to address the technical, economic and safety issues inherent in the exploitation of wind power in a competitive electricity market. Presenting the reader with all the relevant background information key to understanding the integration of wind power into the power systems, this leading edge text: Presents an international perspective on integrating a high penetration of wind power into the power system Offers broad coverage ranging from basic network interconnection issues to industry deregulation and future concepts for wind turbines and power systems Discusses wind turbine technology, industry standards and regulations along with power quality issues Considers future concepts to increase the penetration of wind power in power systems Presents models for simulating wind turbines in power systems Outlines current research activities Essential reading for power engineers, wind turbine designers, wind project development and wind energy consultants dealing with the integration of wind power systems into distribution and transmission networks, this text would also be of interest to network engineers working for power utility companies dealing with interconnection issues and graduate students and researchers in the field of wind power and power systems.

  • 9.
    Ackermann, Thomas
    KTH.
    Wind Power in Power Systems, Second Edition2012Collection/Antologi (Fagfellevurdert)
    Abstract [en]

    The second edition of the highly acclaimed Wind Power in Power Systems has been thoroughly revised and expanded to reflect the latest challenges associated with increasing wind power penetration levels. Since its first release, practical experiences with high wind power penetration levels have significantly increased. This book presents an overview of the lessons learned in integrating wind power into power systems and provides an outlook of the relevant issues and solutions to allow even higher wind power penetration levels. This includes the development of standard wind turbine simulation models. This extensive update has 23 brand new chapters in cutting-edge areas including offshore wind farms and storage options, performance validation and certification for grid codes, and the provision of reactive power and voltage control from wind power plants. Key features: Offers an international perspective on integrating a high penetration of wind power into the power system, from basic network interconnection to industry deregulation; Outlines the methodology and results of European and North American large-scale grid integration studies; Extensive practical experience from wind power and power system experts and transmission systems operators in Germany, Denmark, Spain, UK, Ireland, USA, China and New Zealand; Presents various wind turbine designs from the electrical perspective and models for their simulation, and discusses industry standards and world-wide grid codes, along with power quality issues; Considers concepts to increase penetration of wind power in power systems, from wind turbine, power plant and power system redesign to smart grid and storage solutions. Carefully edited for a highly coherent structure, this work remains an essential reference for power system engineers, transmission and distribution network operator and planner, wind turbine designers, wind project developers and wind energy consultants dealing with the integration of wind power into the distribution or transmission network. Up-to-date and comprehensive, it is also useful for graduate students, researchers, regulation authorities, and policy makers who work in the area of wind power and need to understand the relevant power system integration issues.

  • 10.
    Ackermann, Thomas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Holttinen, H.
    Overview of Integration Studies - Methodologies and Results2012Inngår i: Wind Power in Power Systems, Second Edition, John Wiley & Sons, 2012, 2, s. 361-386Kapittel i bok, del av antologi (Fagfellevurdert)
  • 11.
    Ackermann, Thomas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem. Energynautics GmbH, Germany; Technical University in Darmstadt (TUD), Germany.
    Morthorst, P. E.
    Economic Aspects of Wind Power in Power Systems2005Inngår i: Wind Power in Power Systems, John Wiley & Sons, 2005, s. 383-410Kapittel i bok, del av antologi (Annet vitenskapelig)
  • 12.
    Ackermann, Thomas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Orths, A.
    Rudion, K.
    Transmission Systems for Offshore Wind Power Plants and Operation Planning Strategies for Offshore Power Systems2012Inngår i: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, s. 293-327Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The electric system within an offshore wind power plant and its connection to the main power system pose new challenges to the experts. The best way of interconnecting the wind turbines inside a wind farm has to be found, fulfilling both, redundancy requirements without compromising economic feasibility. The best choice between technologies (HVAC, HVDC - VSC or LCC) for connecting windfarms to shore has to be made, depending on several criteria. The risk of losing this connection versus redundancy has to be economically evaluated. By combining interconnectors and offshore windfarm connections in a modular way, a DC offshore grid can be developed. Anyhow, already during the planning phase the secure operation should be considered thoroughly, because the optimal architecture has to be found, minimizing the necessary assets ensuring secure operation and facilitating later expansion options. The interaction with the onshore grid has to be investigated as well. To enable investigations covering these issues a benchmark offshore test system has been developed which is described in this chapter.

  • 13.
    Ackermann, Thomas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Söder, Lennart
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    The Value of Wind Power2012Inngår i: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, s. 131-155Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The aim of the power plants in a power system is to supply the load in an economical, reliable and environmentally acceptable way. Different power plants can fulfil these requirements in different ways. In order to select the right sources it is important to compare the value of the different sources using an objective approach. The aim of this chapter is describe the different needs of a power system and how these needs can be met with wind power, that is, the value of wind power in a certain system. The values are operating cost value, capacity value, control value, grid loss reduction value and grid investment value. The values can be calculated for different types of power plants, they can be both positive and negative, and they can be calculated both as a physical cost value and a market value.

  • 14.
    Ackermann, Thomas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Tröster, E.
    New Control Concept for Offshore Wind Power Plants: Constant-Speed Turbines on a Grid with Variable Frequency2012Inngår i: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, s. 345-359Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    By using a permanent magnet induction machine as wind generator, the gearbox and converter can be omitted, and the total number of parts reduced leading to a low maintenance and reliable turbine for offshore application. The rotation speed of the turbine however cannot be matched to the wind speed, reducing the energy yield at part load. To overcome this drawback, a central converter can be used, which adjusts the frequency of the local grid in the wind park; this is the so-called park-variable concept. This concept has been compared with respect to energy yield with constant speed and variable speed turbines. Overall, the differences in energy yield of the investigated concepts are so small that other criteria, such as reliability or cost, may be relevant for the selection of one or the other approach. Above all, the park-variable concept represents an interesting alternative to today's common concepts.

  • 15.
    Acuña, José
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Distributed thermal response tests: New insights on U-pipe and Coaxial heat exchangers in groundwater-filled boreholes2013Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    U-pipe Borehole Heat Exchangers (BHE) are widely used today in ground source heating and cooling systems in spite of their less than optimal performance. This thesis provides a better understanding on the function of U-pipe BHEs and Investigates alternative methods to reduce the temperature difference between the circulating fluid and the borehole wall, including one thermosyphon and three different types of coaxial BHEs.

    Field tests are performed using distributed temperature measurements along U-pipe and coaxial heat exchangers installed in groundwater filled boreholes. The measurements are carried out during heat injection thermal response tests and during short heat extraction periods using heat pumps. Temperatures are measured inside the secondary fluid path, in the groundwater, and at the borehole wall. These type of temperature measurements were until now missing.

    A new method for testing borehole heat exchangers, Distributed Thermal Response Test (DTRT), has been proposed and demonstrated in U-pipe, pipe-in-pipe, and multi-pipe BHE designs. The method allows the quantification of the BHE performance at a local level.

    The operation of a U-pipe thermosyphon BHE consisting of an insulated down-comer and a larger riser pipe using CO2 as a secondary fluid has been demonstrated in a groundwater filled borehole, 70 m deep. It was found that the CO2 may be sub-cooled at the bottom and that it flows upwards through the riser in liquid state until about 30 m depth, where it starts to evaporate.

    Various power levels and different volumetric flow rates have been imposed to the tested BHEs and used to calculate local ground thermal conductivities and thermal resistances. The local ground thermal conductivities, preferably evaluated at thermal recovery conditions during DTRTs, were found to vary with depth. Local and effective borehole thermal resistances in most heat exchangers have been calculated, and their differences have been discussed in an effort to suggest better methods for interpretation of data from field tests.

    Large thermal shunt flow between down- and up-going flow channels was identified in all heat exchanger types, particularly at low volumetric flow rates, except in a multi-pipe BHE having an insulated central pipe where the thermal contact between down- and up-coming fluid was almost eliminated.

    At relatively high volumetric flow rates, U-pipe BHEs show a nearly even distribution of the heat transfer between the ground and the secondary fluid along the depth. The same applies to all coaxial BHEs as long as the flow travels downwards through the central pipe. In the opposite flow direction, an uneven power distribution was measured in multi-chamber and multi-pipe BHEs.

    Pipe-in-pipe and multi-pipe coaxial heat exchangers show significantly lower local borehole resistances than U-pipes, ranging in average between 0.015 and 0.040 Km/W. These heat exchangers can significantly decrease the temperature difference between the secondary fluid and the ground and may allow the use of plain water as secondary fluid, an alternative to typical antifreeze aqueous solutions. The latter was demonstrated in a pipe-in-pipe BHE having an effective resistance of about 0.030 Km/W.

    Forced convection in the groundwater achieved by injecting nitrogen bubbles was found to reduce the local thermal resistance in U-pipe BHEs by about 30% during heat injection conditions. The temperatures inside the groundwater are homogenized while injecting the N2, and no radial temperature gradients are then identified. The fluid to groundwater thermal resistance during forced convection was measured to be 0.036 Km/W. This resistance varied between this value and 0.072 Km/W during natural convection conditions in the groundwater, being highest during heat pump operation at temperatures close to the water density maximum.

    Fulltekst (pdf)
    José Acuña - Doctoral Thesis
  • 16.
    Acuña, José
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Palm, Björn
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Distributed thermal response tests on pipe-in-pipe borehole heat exchangers2013Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 109, nr SI, s. 312-320Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Borehole Thermal Energy Storage systems typically use U-pipe Borehole Heat Exchangers (BHE) having borehole thermal resistances of at least 0.06 K m/W. Obviously, there is room for improvement in the U-pipe design to decrease these values. Additionally, there is a need for methods of getting more detailed knowledge about the performance of BHEs. Performing Distributed Thermal Response Tests (DTRT) on new proposed designs helps to fill this gap, as the ground thermal conductivity and thermal resistances in a BHE can be determined at many instances in the borehole thanks to distributed temperature measurements along the depth. In this paper, results from three heat injection DTRTs carried out on two coaxial pipe-in-pipe BHEs at different flow rates are presented for the first time. The tested pipe-in-pipe geometry consists of a central tube inserted into a larger external flexible pipe, forming an annular space between them. The external pipe is pressed to the borehole wall by applying a slight overpressure at the inside, resulting in good thermal contact and at the same time opening up for a novel method for measuring the borehole wall temperature in situ, by squeezing a fiber optic cable between the external pipe and the borehole wall. A reflection about how to calculate borehole thermal resistance in pipe-in-pipe BHEs is presented. Detailed fluid and borehole wall temperatures along the depth during the whole duration of the DTRTs allowed to calculate local and effective borehole thermal resistances and ground thermal conductivities. Local thermal resistances were found to be almost negligible as compared to U-pipe BHEs, and the effective borehole resistance equal to about 0.03 K m/W. The injected power was found to be almost evenly distributed along the depth.

  • 17.
    Adesanya, Adewale A.
    et al.
    Energy and Environmental Analysis Group, New York State Energy Research and Development Authority (NYSERDA), Albany, NY, 12203, USA; Havenergy Consulting Inc, Albany, NY, 12203, USA.
    Sommerfeldt, Nelson
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Pearce, Joshua M.
    Department of Electrical and Computer Engineering, Ivey School of Business, University of Western Ontario, London, ON, N6A 5B9, Canada.
    Achieving 100% Renewable and Self-Sufficient Electricity in Impoverished, Rural, Northern Climates: Case Studies from Upper Michigan, USA2022Inngår i: Electricity, E-ISSN 2673-4826, Vol. 3, nr 3, s. 264-296Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    The development of 100% renewable electricity (RE) systems play a pivotal role in ensuring climate stability. Many municipalities blessed with wealth, an educated and progressive citizenry, and large RE resources, have already reached 100% RE generation. Impoverished municipalities in unwelcoming environments both politically and climatically (e.g., northern latitudes with long, dark winter conditions) appear to be incapable of transitioning to renewables. This study challenges that widespread assumption by conducting a detailed technical and economic analysis for three representative municipalities in the Western Upper Peninsula of Michigan. Each municipality is simulated with their own hourly electricity demand and climate profiles using an electrical supply system based on local wind, solar, hydropower, and battery storage. Sensitivities are run on all economic and technical variables. Results show that transition to 100% RE is technically feasible and economically viable. In all baseline scenarios, the 100% RE systems produced a levelized cost of electricity up to 43% less than the centralized utility rates, which are predominantly fueled by gas and coal. Current policies, however, prevent such self-sufficient systems from being deployed, which are not only detrimental to the global environment, but also aggravate the economic depression of such regions. Potential energy savings advance the prohibitive energy justice principle.

  • 18.
    Aga, Aboma Emiru
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Fuel Supply Investigation for an Externally Fired Microturbine based Micro CHP System: Case study on a selected site in Bishoftu, Ethiopia2013Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Sudden change on earth’s climate, which is a result of an increase in CO2 in the atmosphere, is mainlycaused by burning of fossil fuels for various energy services. However, for the energy services to befavourable to the environment, there should be a balance with the environmental protection, and we cancall that “Sustainable Innovative Development”.

    “EXPLORE Polygeneration” initiative will serve as an important tool to promote the application ofrenewable technologies extending to the future sustainable energy engineering field. This paper is intendedin investigating a suitable fuel supply for the microturbine based micro CHP system available at theDivision of Heat and Power Technology, KTH, Sweden; for a site called “Alema Farm PLC”, Bishoftu,Ethiopia.

    Though there is a large biomass energy resource and a huge potential to produce hydroelectric power inEthiopia, the modern energy sector is very small and the energy system is mainly characterized by biomassfuel supplies and household energy consumption. The nation’s limited biomass energy resource is believedto have been depleting at an increasingly faster rate.

    Of the many and surplus amount of renewable energy resources available in and around Alema FarmPLC, poultry litter and pig’s manure are selected to be the two main energy sources for the CHP systemavailable in the lab, after passing through different conversion techniques. However, after consideringsome basic properties like: Energy content and Bulk Density of the fuel, Moisture content , Ashcharacteristic, Tar content, Fuel logistics, Local storage, Fuel feeder system, and Magnitude of GHGReduction; poultry litter is found to be the most convenient to produce a syngas with a Downdraftatmospheric gasifier available in the HPT lab.

    Finally, For the problems caused by the nature of the poultry litter by itself and the methods used in theconversion process, the 40 TRIZ principles of TRIZ inventive principles is used and some major pointsare recommended.

    Fulltekst (pdf)
    Fuel Supply Investigation for an Externally Fired Microturbine based Micro CHP System
  • 19.
    Ahl, Amanda
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Eklund, Johanna
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Lundqvist, Per
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Yarime, M.
    Balancing formal and informal success factors perceived by supply chain stakeholders: A study of woody biomass energy systems in Japan2018Inngår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 175, s. 50-59Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Small-scale woody biomass energy systems have an inherent ability to aid in emissions reduction while stimulating local economies and, as collective energy systems, are strongly connected to supply chain design based on local conditions and stakeholder integration. Despite an abundance of forest area alongside the promotion of biomass in energy policies, however, woody biomass utilization still remains low in Japan. The woody biomass supply chain, considered as a socio-technical system, involves a complex, cross-sectoral stakeholder network in which inter-organizational dynamics necessitates well-organized management based on an understanding of formal factors such as technology, as well as informal factors such as social relations and culture. In this paper, success factor perceptions from across the woody biomass supply chain are investigated based on semi-structured interviews with four stakeholders in the Kyushu region of Japan. Identified success factors here are: 1) respect of values & traditions, 2) transportation infrastructure, 3) business model integration, 4) relationship & trust, 5) local vitalization and 6) biomass quality control. A convergence as well as divergence of perceptions are observed, involving both formal and informal dimensions. Aiming to balance perceptions and to enable long-term success of woody biomass in Japan, a series of policy implications are drawn, including cross-ministerial integration, knowledge building on wood logistics, forest certification, local coordinators, biomass quality control standards and a feed-in-tariff for heat. This paper suggests a new arena of policy-making based on the importance of considering both informal and formal dimensions in energy policy.

  • 20.
    Ahlfors, Charlotta
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Amelin, Mikael
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Weekly planning of hydropower in systems with large volumes and varying power generation: A literature review2021Inngår i: 2021 IEEE Madrid PowerTech, PowerTech 2021 - Conference Proceedings, Institute of Electrical and Electronics Engineers (IEEE) , 2021, artikkel-id 9495058Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Hydropower is the world's largest source of renewable electricity generation and hydropower plants with reservoirs provide flexibility to the power systems. Efficient planning techniques improve the flexibility of the power systems and reduce carbon emissions, which is needed in power systems exposed to a rapid change. Renewable energy sources, such as wind and solar power, are increasing in the power systems. Hydropower plants have low operating costs and are used as base power. This paper reviews hydropower planning in different time frames and specifically focuses on weekly planning, i.e. hydropower planning for 1 to 3 weeks. Main conclusions in this study are that the term weekly planning is seldom used and the definitions in earlier studies of short term, mid term and long term planning, respectively, varies. The authors propose that weekly planning should belong to mid term planning.

  • 21.
    Ahmed, Amber
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    Gong, Jindan
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    Assessment of the Electricity Generation Mix in Ghana: the Potential of Renewable Energy2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Electricity is a fundamental part a functioning society. Ghana’s electricity system is strained by an ever-growing climate instability and increase of population. Therefore, it is crucial for the country's development that it's electricity supply is done in a sustainable way.

    This report aims to analyze Ghana’s ability to reach SDG 7.1 and the Marrakech Vision, an outcome from the COP 22 meeting in Morocco. This was done by creating a model over Ghana’s electricity system and how it develops over time, called BAU, using the analytical tools: OSeMOSYS and OnSSET. A practical implementation of BAU was then discussed. After that, three development scenarios with different renewable energy targets for the electricity system, were implemented in the model. The results show that CSP and natural gas power plants were the most prominent electricity producers. The growing share of renewable energy in the target scenarios was mostly due to wind power, replacing the natural gas power plants.

    Ghana has local natural gas resources as well as high solar potential. The rising share of renewable energy limits the fossil fuel emission. At the same time, this increased share also endangers the reliability of the electricity supply, as the capacity of renewable energy resources fluctuate and could lead to high investment costs. BAU can be a possible solution which minimizes the fossil fuel consumption and limits the CO2 emissions, but at the risk of possibly having an unreliable electricity supply. To be able to meet SDG 7.1, increasing the share of renewable energy in electricity generation can be a solution, but at the same time, not all requirements of the goal will be fulfilled.

    Fulltekst (pdf)
    fulltext
  • 22.
    Aid, Graham
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi.
    Potential technology for the advanced utilization of construction, demolition, and industrial waste2008Konferansepaper (Fagfellevurdert)
  • 23.
    Akdemir, Gabriel
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Tellgren, Sebastian
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Styr- och reglerstrategier i termisktenergilager med fasändring2020Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    See filen

    Fulltekst (pdf)
    fulltext
  • 24.
    Alahakoon, Sanath
    et al.
    Central Queensland University, Australia.
    Leksell, Mats
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Emerging energy storage solutions for transportation - A review: An insight into road, rail, sea and air transportation applications2015Inngår i: Electrical Systems for Aircraft, Railway and Ship Propulsion, ESARS, IEEE , 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Increasing usage of hybrid electric vehicles, plug-in electric vehicles and emerging new concepts in transportation such as electric highways have raised the significant role of energy storage solutions for transportation to its highest level. It is impossible to specify a single energy storage solution that can satisfactorily fulfill the varying performance demands of various applications in transportation. This paper will identify some of the most demanded performance requirements from some of the key applications in transportation and assess the suitability of emerging energy storage solutions against those.

  • 25.
    Alahakoon, Sanath
    et al.
    Cent Queensland Univ, Sch Engn & Technol, Ft Wayne, IN 4680 USA. eksell, Mats; Ostlund, Stefan.
    Leksell, Mats
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Östlund, Stefan
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Emerging Energy Storage Solutions for Transportation Electrification - A view2019Inngår i: International Journal of Engineering and Technology Innovation, ISSN 2223-5329, E-ISSN 2226-809X, Vol. 9, nr 2, s. 75-90Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Energy storages have caught the attention of transportation community r the past several years. Rsecent developments in hybrid and plug-in ectric vehicles together with novel concepts in transportation such as ectric highways are the reasons for raising the role of energy orages in transportation to such a significant level. Performance mands for energy storage solutions vary significantly from one ansportation application to the other, making it difficult for the ientific community to converge to a single energy storage solution at caters all. This paper reviews the key performance demands of the jor transportation applications. It also investigates the aracteristics of emerging energy storage solutions and assess their itability for those reviewed transportation applications.

  • 26.
    Albrecht, Martin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms).
    Enabling socio-technical transitions – electric vehicles and high voltage electricity grids as focal points of low emission futures2017Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Today humankind is facing numerous sustainability challenges that require us to question CO2 intensive practices like those present in the transport and energy sector. To meet those challenges, many countries have adopted ambitious climate targets. Achieving such targets requires an understanding of the wider socio-technical context of transitions. The aim of this licentiate thesis is therefore to analyse such socio-technical transitions towards low-emission futures enabled by the electrification of passenger cars and high voltage grid development.

    A combination of different transitions theories (for ex. Multi-level perspective and Technological innovation systems) and institutional theory has been used. To reach the aim paper I analyses the climate impacts of electric vehicles (EVs) and policy measures to achieve a breakthrough scenario for EVs. The results show that a mixture of short and long term policies are needed that take into account the technology development stage and behavioural aspects of EV adopters. Paper II addresses the need to include the high voltage transmission grid and its planning procedures as a central part of debates on transitions. Therefore the opportunities, challenges and reasons for conflict in the established regime are studied. The results show that in order to achieve a sustainable grid development regime, it is necessary to spend time on achieving legitimacy and social sustainability. The third paper uses semi-structured expert interviews and focuses on innovation dynamics for EV adoption. By focusing on dynamics instead of single policy measures, it is possible to grasp interactions within a niche, but also in between a niche, regime and landscape. The results show that strong initial technology legitimacy was needed to start substantial innovation dynamics. This could be further strengthened with a strong and broad coalition of actors. Both those factors led, if present, to an improved variety and match of policy instruments.

    As such this thesis has shown that transitions are not just about technology or policy instruments as such but about the dynamics and processes needed to enable them. This can be relevant in other transitions that otherwise may underestimate the importance of these components.

    Fulltekst (pdf)
    fulltext
  • 27.
    Albrecht, Martin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms).
    Nordic power road map 2050: Strategic choices towards carbon neutrality. D4.1.R Institutional grid review.2013Rapport (Annet vitenskapelig)
    Fulltekst (pdf)
    fulltext
  • 28.
    Albrecht, Martin
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Miljöstrategisk analys (fms).
    System innovation dynamics around electric vehicles. The cases of Norway, Denmark and Sweden.Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    This paper focuses on the comparison of electric car innovation patterns in Norway, Sweden and Denmark. Doing so, it takes a closer look at what the most essential dynamics in the systems were over time and what enabled those dynamics. The main research aim is to contribute to a wider understanding of why Norway is so much ahead of Sweden and Denmark in electric car adoption. The purpose is also to adopt a perspective that goes beyond a mere focus on economic policy instruments. In order to do so different theory elements are combined in a framework. These elements stem from the transition theory literature field, especially the technological innovation system (TIS) and the multi-level perspective (MLP). This combination allows analysing the development behind a dynamic, not just when it comes to an innovation itself but also with regards to the established regime. The data is gathered through analysis of existing documents and data as well as a series of 27 expert interviews conducted in the three case countries. The findings suggest that there are important differences in transition patterns that can account for the electric vehicle (EV) diffusion situation we can find nowadays in the three Nordic countries. An important stepping stone was the need for a very strong legitimacy of the original EV vision that is also anchored in a coordinated, sector overarching coalition of actors that thinks strategically and long term. Moreover some general beneficial dynamics could be identified across the countries in question. In Norway these beneficial dynamics can be summarised as a systems motor, in Denmark as a failed entrepreneurial motor that shifted towards a constrained municipal motor and in Sweden as a loosely, coordinated and weaker version of a systems motor.

  • 29.
    Alessandro, Magny
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Installations- och energisystem.
    Pdungsilp, Aumnad
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Installations- och energisystem.
    Martinac, Ivo
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Installations- och energisystem.
    Optimization of Energy Supply Systems for a Sustainable District in Stockholm Using Genetic Algorithms2014Inngår i: Proceedings of the World Sustainable Buildings Conference 2014, 2014Konferansepaper (Fagfellevurdert)
  • 30.
    Ali, Amjad
    et al.
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan.;Univ Okara, Dept Phys, Okara 56300, Pakistan.;KTH, Dept Mat Sci & Engn, SE-10044 Stockholm, Sweden..
    Bashir, Farrukh Shehzad
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Raza, Rizwan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik. COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan.;Royal Inst Technol KTH, Dept Energy Technol, S-10044 Stockholm, Sweden..
    Rafique, Asia
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Ullah, Muhammad Kaleem
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Alvi, Farah
    COMSATS Univ, Dept Phys, CERL, Lahore Campus, Lahore 54000, Pakistan..
    Afzal, Muhammad
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Ghauri, Moinuddin
    COMSATS Univ Islamabad, Dept Chem Engn, Lahore Campus, Lahore 54000, Pakistan..
    Belova, Lyubov
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Strukturer.
    Electrochemical study of composite materials for coal-based direct carbon fuel cell2018Inngår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, nr 28, s. 12900-12908Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The efficient conversion of solid carbon fuels into energy by reducing the emission of harmful gases is important for clean environment. In this regards, direct carbon fuel cell (DCFC) is a system that converts solid carbon directly into electrical energy with high thermodynamic efficiency (100%), system efficiency of 80% and half emission of gases compared to conventional coal power plants. This can generate electricity from any carbonaceous fuel such as charcoal, carbon black, carbon fiber, graphite, lignite, bituminous coal and waste materials. In this paper, ternary carbonate-samarium doped ceria (LNK-SDC) electrolyte has been synthesized via co-precipitation technique, while LiNi-CuZnFeO (LNCZFO) electrode has been prepared using solid state reaction method. Due to significant ionic conductivity of electrolyte LNK-SDC, it is used in DCFC. Three types of solid carbon (lignite, bituminous, sub-bituminous) are used as fuel to generate power. The X-ray diffraction confirmed the cubic crystalline structure of samarium doped ceria, whereas XRD pattern of LNCZFO showed its composite structure. The proximate and ultimate coal analysis showed that fuel (carbon) with higher carbon content and lower ash content was promising fuel for DCFC. The measured ionic conductivity of LNK-SDC is 0.0998 Scm(-1) and electronic conductivity of LNCZFO is 10.1 Scm(-1) at 700 degrees C, respectively. A maximum power density of 58 mWcm(-2) is obtained using sub bituminous fuel.

  • 31.
    Alikhani, Parnian
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Bertling, Lina
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Astner, Linda
    Port Gävle, Gävle, Sweden..
    Donnerstal, Pontus
    Port Gävle, Gävle, Sweden..
    Forecasting the Electrical Demand at the Port of Gavle Container Terminal2021Inngår i: 2021 IEEE PES INNOVATIVE SMART GRID TECHNOLOGY EUROPE (ISGT EUROPE 2021), Institute of Electrical and Electronics Engineers (IEEE) , 2021, s. 806-811Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The port industry is transforming into a smart port thanks to technological advancements and environmental expectations. Developing a sustainable maritime transportation system and its beneficial electrification as a proven approach in emissions reduction are gathering momentum due to technological growth. Global containerization leads to high electricity demand at container terminals, and the electricity demand is highly dynamic and dependent on different operation processes. The approach of this paper is to forecast the hourly peak load demand and short-term electricity demand profile in a container terminal. The correctly forecasted electricity demand profile is crucial for less expensive and reliable power operation and planning. First, Artificial Neural Network (ANN) method is used to predict the container terminal baseload demand. Second, worst-case simultaneous peak load is estimated. Third, the day-ahead load profile is modeled based on the handling operation scheduled for the day. The approach is implemented at the container terminal in Port of Gavle, and the results, including the baseload forecasting, the peak power demand, and the hourly load profile modeling by 2030, have been used in dialogue with the local energy company for the future predicted need of load.

  • 32.
    Alikhani, Parnian
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Bertling, Lina
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Elektroteknik, Elkraftteknik.
    Astner, Linda
    Gävle Hamn AB.
    Donnerstål, Pontus
    Gävle Hamn AB.
    Forecasting the Electrical Demand at the Port of Gävle Container Terminal2021Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The port industry is transforming into a smart port thanks to technological advancements and environmental expectations. Developing a sustainable maritime transportation system and its beneficial electrification as a proven approach in emissions reduction are gathering momentum due to technological growth. Global containerization leads to high electricity demand at container terminals, and the electricity demand is highly dynamic and dependent on different operation processes. The approach of this paper is to forecast the hourly peak load demand and short-term electricity demand profile in a container terminal. The correctly forecasted electricity demand profile is crucial for less expensive and reliable power operation and planning. First, Artificial Neural Network (ANN)method is used to predict the container terminal baseload demand. Second, the worst-case simultaneous peak load is estimated. Third, the day-ahead load profile is modeled based on the handling operation scheduled for the day. The approach is implemented at the container terminal in Port of Gävle, and the results, including the baseload forecasting, the peak power demand, and the hourly load profile modeling by 2030, have been used in dialogue with the local energy company for the future predicted need of load.

  • 33.
    Alisic, Rijad
    et al.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Pare, Philip E.
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Sandberg, Henrik
    KTH, Skolan för elektroteknik och datavetenskap (EECS), Centra, ACCESS Linnaeus Centre. KTH, Skolan för elektroteknik och datavetenskap (EECS), Intelligenta system, Reglerteknik.
    Modeling and Stability of Prosumer Heat Networks2019Inngår i: IFAC PAPERSONLINE, ELSEVIER , 2019, Vol. 52, nr 20, s. 235-240Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The energy sector is going through a large transformation due to public demands of renewable energy sources. However, a major issue is that these energy sources are intermittent. If designed correctly, district heating systems can naturally contain energy storing units, for example by storing heat in the isolated pipes that make up the heat grid. Additionally, this makes it easier to reuse and transport already generated heat to other users. This paper proposes a mathematical model of such a grid, where excess energy can be retracted from one user and distributed to other users using a network of heat pumps. In some cases, one can balance residual heat production with the heat consumption, temporarily eliminating the need for a centralized heating plant. Existence conditions for stable steady states of such a network with general topology are given. Finally, energy optimal stable steady states are obtained through convex optimization. 

  • 34.
    Allington, Lucy
    et al.
    Loughborough Univ, STEER Ctr, Dept Geog & Environm, Loughborough, Leics, England..
    Cannone, Carla
    Loughborough Univ, STEER Ctr, Dept Geog & Environm, Loughborough, Leics, England..
    Pappis, Ioannis
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Usher, William
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystem.
    Taliotis, Constantinos
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik. Cyprus Inst, Nicosia, Cyprus..
    Sundin, Caroline
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Sridharan, Vignesh
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Ramos, Eunice
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Rogner, Hans-Holger
    To, Long Seng
    Loughborough Univ, STEER Ctr, Dept Geog & Environm, Loughborough, Leics, England..
    Selected 'Starter kit' energy system modelling data for selected countries in Africa, East Asia, and South America (#CCG, 2021)2022Inngår i: Data in Brief, E-ISSN 2352-3409, Vol. 42, s. 108021-, artikkel-id 108021Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Energy system modeling can be used to develop internally consistent quantified scenarios. These provide key insights needed to mobilise finance, understand market development, infrastructure deployment and the associated role of institutions, and generally support improved policymaking. However, access to data is often a barrier to starting energy system modeling, especially in developing countries, thereby causing delays to decision making. Therefore, this article provides data that can be used to create a simple zero-order energy system model for a range of developing countries in Africa, East Asia, and South America, which can act as a starting point for further model development and scenario analysis. The data are collected entirely from publicly available and accessible sources, including the websites and databases of international organisations, journal articles, and existing modeling studies. This means that the datasets can be easily updated based on the latest available information or more detailed and accurate local data. As an example, these data were also used to calibrate a simple energy system model for Kenya using the Open Source Energy Modeling System (OSeMOSYS) and three stylized scenarios (Fossil Future, Least Cost and Net Zero by 2050) for 2020-2050. The assumptions used and the results of these scenarios are presented in the appendix as an illustrative example of what can be done with these data. This simple model can be adapted and further developed by in-country analysts and academics, providing a platform for future work.

  • 35.
    Almulla, Youssef
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystem.
    Energy-Water and Agriculture Nexus to Support the Sustainable Management of Shared Water Resources2023Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Throughout history, major rivers and shared water bodies have allowed civilizations to flourish, and the effective management of shared water bodies has always been a priority for societies and nations. Today, about 40% of the world’s population lives in proximity to the 286 transboundary river and lake basins that supply 60% of the world’s freshwater flows and make up about half of the Earth’s land area. Moreover, around 2 billion people in the world depend on groundwater sources, which include over 460 transboundary aquifer systems.

    The mismanagement of water resources can result in catastrophic disasters that are often exacerbated by a domino effect so that the impacts of poor water management often extend beyond the water system. The interdependency of the water system with other systems such as energy and food, or with land-use, highlights the importance of ”systems thinking and planning” in resource management. Such a concept is not easily encapsulated into policy-making processes in many parts of the world because consideration of the resource systems in isolation as individual entities and ‘silo” thinking still dominate. Climate change adds another layer of complexity and exacerbates the issue of water management. Another important factor is geographical location because precipitation varies among and within continents. This results in some regions suffering from water shortages and some regions facing the risks of water redundancy and floods. 

    The concept of the Water-Energy-Food (WEF) nexus was introduced in 2011 as a response to help address some of the issues mentioned above. Over the last decade, research on the WEF nexus has gained momentum in both the policy and academic areas and several methods have been introduced to operationalize the nexus in different contexts. One of the flagship methodologies is the Transboundary Basins Nexus Approach (TBNA) introduced by the United Nations Economic Commission of Europe (UNECE) in 2015 and designed to assess the nexus in shared (transboundary) water basins.

    The aim of this thesis is to support shared water management by using the WEF-nexus approach to quantify the benefits of coordinated management, motivate cooperation, and identify trade-offs in the optimal use of resources. To achieve this aim, four research questions are explored over the course of four academic publications.  

    The first question explores the role of the energy sector in motivating shared water cooperation. The second question studies the risks and opportunities emerging from the interplay between climate and renewable energy in shared basins. The third question focuses on groundwater management and explores what benefits the consideration of the energy-water-agriculture nexus could bring to shared groundwater management in water-scarce areas. The fourth question examines how consideration of the energy-water-agriculture nexus could accelerate the low-carbon transition in the agricultural sector. 

    These research questions are examined in two different, yet complementing, geographic locations. One is the Balkans in Southeastern Europe, which faces water redundancy and flood issues and the other is the Middle East and North Africa (MENA) region which suffers from water scarcity. In the first region, the Drina and the Drin River Basins represent the characteristics of Southeastern Europe while the North Western Sahara Aquifer System (NWSAS) and the Souss-Massa basin represent the characteristics of the MENA region. Three of the case applications are transboundary (Drina, Drin and NWSAS) while the last application (Souss-Massa Basin) is a subnational basin.  

    Fulltekst (pdf)
    fulltext
  • 36.
    Almulla, Youssef
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystemanalys.
    Gulf Cooperation Council (GCC) countries 2040 energy scenario for electricity generation and water desalination.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Judicious modeling of an energy system can help provide insights as to how elements of the energy system might be configured in the longer term. The current and future electricity and water desalination systems of each GCC country were represented using a full-cost based optimization tool called MESSAGE and the following scenarios were examined:

    1. The business as usual scenario (BAU): current energy system is extended into the future without any changes. The energy system structure and characteristics are kept the same. The fuel prices are also kept at the current subsidized levels.

    2 - The netback-pricing scenario: all fuel costs are increased to the international market price. The freed amount of fuel is assumed to be available for export to the international market. Moreover, this scenario examines different carbon tax options of 0, 20,30 ,40 and 50 dollars per kilo tons of CO2 emissions.

    3 - The Nuclear hub scenario: examines the idea of a “nuclear hub” state for the GCC region that can have all the “know-how” and logistics to provide sufficient nuclear energy for the GCC through the Interconnection Grid “GCCIG”.

    Results shows that fossil fuels will continue to play an important role in a least cost future for the region. This is due, in no small part, to the cheap natural gas resources in the GCC. Despite the high renewable energy technologies potential, their penetration – given the study assumptions - proved to be important, but limited in the GCC. On the other hand, nuclear energy shows clear economic potential. 

    Fulltekst (pdf)
    fulltext
  • 37.
    Almulla, Youssef
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystem.
    Zaimi, Klodian
    Polytechnic University of Tirana (UPT).
    Fejzic, Emir
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystem.
    Sridharan, Vignesh
    Imperial College London.
    De Strasser, Lucia
    UNECE.
    Gardumi, Francesco
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystem.
    Hydropower and Climate Change, insights from the Integrated Water-Energy modelling of the Drin Basin.Manuskript (preprint) (Annet vitenskapelig)
    Abstract [en]

    The understanding of the transboundary impact of Climate Change on hydropower is not well-established in the literature, where few studies take a system perspective to understand the relative roles of different technological solutions for coordinated water and energy management. This study contributes to addressing this gap by introducing an open-source, long-term, technologically-detailed water and energy resources cost-minimisation model for the Drin River Basin, built in OSeMOSYS. 

    The analysis shows that climate change results in a 15-52% annual decline in hydro generation from the basin by mid-century. Albania needs to triple its investments in solar and wind to mitigate the risk of climate change. Changing the operational rules of hydropower plants has a minor impact on the electricity supply. However, it can spare significant storage volume for flood control. 

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  • 38.
    Al-Robaye, Ali
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Medicinteknik och hälsosystem, Hälsoinformatik och logistik.
    Svenska laddningsinfrastrukturen: Studie om hur den svenska laddningsinfrastrukturen måste utvecklas för att kunna tillgodose en fortsatt omställning av fossildrivna fordon till elektriska.2024Independent thesis Basic level (university diploma), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Hela världen står inför nya utmaningar till följd av klimatförändringar. I syfte att mitigera människans påverkan på klimatet har den Europeiska unionen och Sverige som EU-land beslutat att fasa ut användningen av fossila drivmedel. Omställningen från fossildrivna fordon till eldrivna har påbörjats men Sverige är i dagsläget långt ifrån en fullständig omställning. Förutsättningen för att en hundraprocentig omställning skall vara möjlig är att en fungerande laddningsinfrastruktur är på plats och kan hantera det ökande behovet av laddning. I denna rapport studeras den nuvarande svenska laddningsinfrastrukturen och de faktorer som hämmar en fortsatt utveckling presenteras. Avslutningsvis redovisas det att satsning på publik- och hemmaladdning är viktiga faktorer i alla nivåer av omställning, insyn och samverkar är något som saknas idag och är något som måste finnas för att fullständig omställning skall vara möjlig.

    Fulltekst (pdf)
    Ali_A_EX
  • 39. AlSkaif, T.
    et al.
    Zapata, M. G.
    Bellalta, B.
    Nilsson, Anders
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik.
    A distributed power sharing framework among households in microgrids: a repeated game approach2016Inngår i: Computing, ISSN 0010-485X, E-ISSN 1436-5057, Vol. 99, nr 1, s. 23-37Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In microgrids, the integration of distributed energy resources (DERs) in the residential sector can improve power reliability, and potentially reduce power demands and carbon emissions. Improving the utilization of renewable energy in households is a critical challenge for DERs. In this regard, renewable power sharing is one of the possible solutions to tackle this problem. Even though this solution has attracted significant attention recently, most of the proposed power sharing frameworks focus more on centralized schemes. In contrast, in this paper, the performance of a proposed distributed power sharing framework is investigated. The problem is formulated as a repeated game between households in a microgrid. In this game, each household decides to cooperate and borrow/lend some amount of renewable power from/to a neighboring household, or to defect and purchase the entire demands from the main grid based on a payoff function. The Nash equilibrium of this game is characterized and the effect of the strategies taken by the households on the system is analyzed. We conduct an extensive evaluation using real demand data from 12 households of different sizes and power consumption profiles in Stockholm. Numerical results indicate that cooperation is beneficial from both an economical and environmental perspective and that households can achieve cost savings up to 20 %.

  • 40.
    Alvehag, Karin
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Söder, Lennart
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Quality regulation impact on investment decisions in distribution system reliability2012Inngår i: 9th International Conference on the European Energy Market, EEM 12, IEEE , 2012, s. 6254646-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Performance-based regulations accompanied by quality regulations are gaining ground. Quality regulations imply new financial risks for the distribution system operator (DSO). In fact, the development of the regulatory model has been identified as a key factor in operations planning for a DSO. Lifetimes of distribution system components are very long and how the quality regulation might develop in the future is unknown. This paper develops a method - the regulation impact method - that can be used to investigate how changes in the quality regulation parameters affect the economic performance of an investment strategy. The proposed regulation impact method is based on net present value calculations of the total reliability cost. The new method is applied to the current Swedish quality regulation in a case study. In the case study, possible future parameter changes and their effect on the DSO's financial risk when adopting different investment strategies are investigated. With the new method it is possible to analyze how robust an investment strategy is to changes in quality regulation design.

  • 41.
    Amelin, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    An Evaluation of Intraday Trading and Demand Response for a Predominantly Hydro-Wind System Under Nordic Market Rules2015Inngår i: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 30, nr 1, s. 3-12Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many countries are planning for a large-scale expansion of wind power. This development will have a significant impact on power system operation and economics. One of the challenges is that the difficulty to forecast wind power generation will increase the need for real-time balancing. This paper presents a study of how the impact of wind power forecast errors can be reduced by changes in the market design. The study is based on the conditions in the Nordic electricity market. A characteristic of this market is that there is a large share of flexible hydro generation; hence, ramp and unit commitment constraints rarely constrain dispatch. The need for regulation during real-time is provided in a voluntary real-time balancing market, where players can be compensated for their redispatch costs. Case studies are presented which show that a shift from day-ahead to intraday trading and increased demand response can improve the performance when the share of wind power is increasing.

  • 42. Ammenberg, J.
    et al.
    Anderberg, S.
    Lönnqvist, Tomas
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Energiprocesser.
    Grönkvist, Stefan
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Energiprocesser.
    Sandberg, Thomas
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekonomi och organisation (Inst.).
    Biogas in the transport sector—actor and policy analysis focusing on the demand side in the Stockholm region2018Inngår i: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 129, s. 70-80Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sweden has ambitions to phase out fossil fuels and significantly increase the share of biofuels it uses. This article focuses on Stockholm County and biogas, with the aim to increase the knowledge about regional preconditions. Biogas-related actors have been interviewed, focusing on the demand side. Biogas solutions play an essential role, especially regarding bus transports and taxis. Long-term development has created well-functioning socio-technical systems involving collaboration. However, uncertainties about demand and policy cause hesitation and signs of stagnating development. Public organizations are key actors regarding renewables. For example, Stockholm Public Transport procures biogas matching the production at municipal wastewater treatment plants, the state-owned company Swedavia steers via a queuing system for taxis, and the municipalities have shifted to “environmental cars”. There is a large interest in electric vehicles, which is expected to increase significantly, partially due to suggested national policy support. The future role of biogas will be affected by how such an expansion comes about. There might be a risk of electricity replacing biogas, making it more challenging to reach a fossil-free vehicle fleet. Policy issues strongly influence the development. The environmental car definition is of importance, but its limited focus fails to account for several different types of relevant effects. The dynamic policy landscape with uncertainties about decision makers’ views on biogas seems to be one important reason behind the decreased pace of development. A national, long-term strategy is missing. Both the European Union and Sweden have high ambitions regarding a bio-based and circular economy, which should favor biogas solutions.

  • 43.
    Ancel, Julie
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Improvement of the electrical part of Idénergie's hydrokinetic turbine2014Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Idénergie develops the first domestic hydrokinetic turbine for rivers. Itaims at producing about 100W in a 1.4m/s river to power up remote locations.Idénergie’s turbine has two main advantages: a completely watertight shaftlessgenerator and an integrated smart converter. The first turbines are planned tobe sold in June 2014.To be able to test the embedded intelligence in the lab, Idénergie’s testbench must be able to reproduce river conditions. Measurements have beenperformed in a river and provide the torque developed by the river at differentspeeds. On the test bench controlled by a LabView program, the rotationalspeed is measured and the corresponding torque computed. This torque is setas the new command and makes the test bench behave as if it was driven by aturbine in a river.Idénergie’s generator contains a rotor made of permanent magnets.These magnets are provided by a supplier and their quality needs to bechecked. For this purpose, a magnetometer is designed and built. It contains 5Hall effect sensors which move at a constant speed above a magnet andmeasure its magnetic field. The magnetometer is able to compare magnets to areference and to detect the faulty ones. The sensors are also used to measurethe magnetic field of the rotor and show that the custom-made shape of themagnets has no influence on the sinusoidal field.The converter transforms the three-phase current to direct current andcontrols the rotational speed. This is done thanks to an embedded electroniccard, which is about to be working properly. The Maximum Power PointTracking algorithm ensures that the rotational speed is optimum in order toproduce the maximum power output. The code loaded on this card is written inits main part but needs to be tested on the test bench once the card will beoperational.

  • 44.
    Andersson, Carl
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    Olausson, Linus
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    Identifiering av mervärden i EPC-projekt2015Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    In this report a study is carried out with the aim to identify added values of EPC projects implemented in schools in order to increase the interest of EPC projects on the market. The report examines how the planned maintenance, supervision, maintenance and corrective maintenance is affected, how insurance premiums and terms are affected, the indoor environment and how the tasks of the operating staff is changing. A literature study of energy savings, energy use in schools, maintenance and insurance as well as how energy efficiency improvements are related to the Swedish environmental objectives has been made. Visits were carried out in Ludvika, interviews were also carried out with operation technicians and local strategists in Ludvika as well as employees of insurance companies.

    Schools often have neglected maintenance and problems with ventilation and indoor environment. Schools also have a large energy saving potential due to their low utilization, mainly because they are empty parts of the year. All Swedish schools could reduce their electricity consumption by 1 TWh per year, which in money equivalents to the salary costs of about 2,000 teaching positions.

    8 schools in Ludvika and 10 schools in Piteå who has completed EPC projects have been studied. The time periods studied are seven years for Ludvika, 2006 – 2012, and for Piteå five years, 2010 – 2014. The data of fault reports and maintenance costs are taken from the municipalities, and descriptions of schools and EPC projects have been received from Caverion who has carried out the EPC projects. Data for maintenance has to some extent been selected in consultation with employees at the municipalities.

    The number of error reports in Piteå schools have shown a slight downward trend with a peak while the EPC project was carried out and one year after. Ludvika has shown an upward trend in maintenance costs, but this is probably due to previously accumulated maintenance. The amount of corrective maintenance is reduced, but only after the project when newly found errors have been fixed and the systems have been properly adjusted. The tasks related to supervisory and maintenance has changed when remote control of systems was installed which leads to a better overview and simplifies troubleshooting. The indoor temperature got more stable, but only after they fixed the weaknesses revealed in connection with the operational optimization. However, there are complaints in Ludvika of low temperatures, but it is caused the target temperature being set too low by the municipality. Insurance is only marginally affected, and only when damage prevention measures are implemented in the properties, which is not done in the studied properties. However, the underlying data sets are too small and over a too small time period to prove any certain changes.

    An added value identified is the ability to use EPC projects as a tool to address deferred maintenance in the real estate portfolio outside the normal budgetary framework while achieving energy savings. 

    Fulltekst (pdf)
    fulltext
  • 45.
    Andersson, Elin
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi.
    Use cases and Business Models: Urban Smart Grid2011Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The EU has established a climate and energy package that includes solutions of the threatening climate changes and is called the 202020 package. The goal is to reduce the greenhouse gases with 20 % until the year 2020. The energy use should be lowered with20 % and the energy efficiency will be 20% higher.

    On account of this, Stockholm city is developing a new city district which is called Stockholm Royal Seaport. The vision of Stockholm Royal Seaport is to develop a sustainable city district that should contribute to innovation, development and promotion of the Swedish environmental technology. Through a new and more efficient grid, Smart Grid, the total energy usage will be lowered, the load optimized and it will be possible to connect decentralized electricity recourses as well as integrate electric vehicles. To make the Smart Grid implementation as good as possible use cases have been a big part of the preparatory work. A use case is a document consisting of one or several scenarios that describe how actors, who could be a human or a piece of hardware, interact with the system to reach a specific goal.

    This master thesis has been performed at and assigned by Fortum. The aim of the study was to deliver ideas and suggestions for new markets and business models and create new incitements, which will be needed to succeed with the implementation of Smart Grid; this will be done especially with regards to sustainable development. During the project around 170 existing use cases were organised depending on which area in the grid they belonged to. This was done so that an area in Stockholm Royal Seaport could be picked out to be deeper analysed. The use cases concerning the integration and use of the electric vehicle went through a closer study to evaluate what changes are needed in management, regulation etc., in order to success with the development of the new grid. The "new" aim of this study became to show the differences in how much carbon dioxide the electric vehicle emits and how much its owner pays in taxes compared to a regular vehicle. The two vehicles that have been compared are both from Renault. The emissions from the electric vehicle are considerate to be equal to the emission from production of the used electricity. The emissions have been calculated using historical electricity production data together with a production forecast of the year of 2020. The outcome of the calculations differs depending on if the vehicle "uses" the total production mix or the electricity produced on the margin. The results show that the electric vehicle pays a third less in taxes: if one looks at the total costs for the vehicles, the investment of the electric vehicle has a payback time of ten years. Substitute a conventional vehicle for the electric vehicle reduces the carbon dioxide emissions between 0,54 and 1,67 ton a year. This indicates that a differentiated carbon dioxide tax would be favouring the electric vehicle and also makes one pay for what one emits.

  • 46.
    Andersson, Joakim
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Energiprocesser.
    Application of Liquid Hydrogen Carriers in Hydrogen Steelmaking2021Inngår i: Energies, E-ISSN 1996-1073, Vol. 14, nr 5, s. 1392-Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Steelmaking is responsible for approximately one third of total industrial carbon dioxide (CO2) emissions. Hydrogen (H2) direct reduction (H-DR) may be a feasible route towards the decarbonization of primary steelmaking if H2 is produced via electrolysis using fossil-free electricity. However, electrolysis is an electricity-intensive process. Therefore, it is preferable that H2 is predominantly produced during times of low electricity prices, which is enabled by the storage of H2. This work compares the integration of H2 storage in four liquid carriers, methanol (MeOH), formic acid (FA), ammonia (NH3) and perhydro-dibenzyltoluene (H18-DBT), in H-DR processes. In contrast to conventional H2 storage methods, these carriers allow for H2 storage in liquid form at moderate overpressures, reducing the storage capacity cost. The main downside to liquid H2 carriers is that thermochemical processes are necessary for both the storage and release processes, often with significant investment and operational costs. The carriers are compared using thermodynamic and economic data to estimate operational and capital costs in the H-DR context considering process integration options. It is concluded that the use of MeOH is promising compared to the other considered carriers. For large storage volumes, MeOH-based H2 storage may also be an attractive option to the underground storage of compressed H2. The other considered liquid H2 carriers suffer from large thermodynamic barriers for hydrogenation (FA) or dehydrogenation (NH3, H18-DBT) and higher investment costs. However, for the use of MeOH in an H-DR process to be practically feasible, questions regarding process flexibility and the optimal sourcing of CO2 and heat must be answered

    Fulltekst (pdf)
    fulltext
  • 47.
    Andersson, Joakim
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Energiprocesser.
    Non-geological hydrogen storage for fossil-free steelmaking2022Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In the last half-century, global steel use has increased more than threefold and further growth is expected, particularly in developing economies. However, steelmaking is currently responsible for 7% of the global net carbon dioxide (CO2) emissions, and any substantial further optimization of existing processes that utilize fossil fuels for iron ore reduction is infeasible. Therefore, steelmaking must change for climate change mitigation targets to be achievable. Hydrogen (H2) steelmaking using H2 produced via electrolysis is one way forward. A challenge is the substantial electricity demand of electrolysis. H2 storage may lower the electricity cost of electrolysis by allowing a larger share of H2 to be produced when the electricity price is low. Existing experience with large-scale H2 storage is limited to salt caverns and the construction of such caverns requires suitable geological formations, which are neither ubiquitous nor well-distributed. However, geologically-independent H2 storage technologies have not previously been evaluated for integration with H2 steelmaking. This is the aim of this thesis. H2 storage technologies were reviewed and liquid H2 carriers were identified as the most techno-economically feasible non-geological options. Out of these liquid carriers, methanol (CH3OH) was found particularly promising for H2 steelmaking due to the low heat demand of its dehydrogenation, its low-cost storage, and the high technological readiness of plants for both its production and dehydrogenation. A complete CH3OH-based H2 storage concept was developed, including processes for CO2 and heat supply. Its ability to reduce the H2 production cost in a H2 steelmaking process was evaluated via a deterministic optimization method based on historical electricity prices. Results indicate that CH3OH-based storage may be competitive with geological storage options, especially for cases with long-duration electricity price patterns.  The option to also sell off accumulated CH3OH from the storage was investigated. Such steel and CH3OH co-production may improve storage utilization and reduce the risk of investment into H2 storage as it allows for profitability to be reached under a more diverse set of electricity market conditions.

    Fulltekst (pdf)
    Kappa
  • 48.
    Andersson, Joakim
    et al.
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Energiprocesser.
    Krüger, Andries
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Tillämpad elektrokemi.
    Grönkvist, Stefan
    KTH, Skolan för kemi, bioteknologi och hälsa (CBH), Kemiteknik, Energiprocesser.
    Methanol as a carrier of hydrogen and carbon in fossil-free production of direct reduced iron2020Inngår i: Energy Conversion and Management: X, E-ISSN 2590-1745, Vol. 7, nr 100051Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Steelmaking is responsible for around 7% of the global emissions of carbon dioxide and new steelmaking processes are necessary to reach international climate targets. As a response to this, steelmaking processes based on the direct reduction of iron ore by hydrogen produced via water electrolysis powered by renewable electricity have been suggested. Here we present a novel variant of hydrogen-based steelmaking incorporating methanol as a hydrogen and carbon carrier together with high-temperature co-electrolysis of water and carbon dioxide and biomass oxy-fuel combustion. The energy and mass balances of the process are analyzed. It is found that this methanol-based direct reduction process may potentially offer a number of process-related advantages over a process based on pure hydrogen, featuring several process integration options. Notably, the electricity and total energy use of the steelmaking process could be reduced by up to 25% and 8% compared to a reference pure-hydrogen process, respectively. The amount of high-temperature (>200 °C) heat that must be supplied to the process could also be reduced by up to approximately 34%, although the demand for medium-temperature heat is substantially increased. Furthermore, the suggested process could allow for the production of high-quality direct reduced iron with appropriate carburization to alleviate downstream processing in an electric arc furnace, which is not the case for a process based on pure hydrogen.

    Fulltekst (pdf)
    fulltext
  • 49.
    Andersson, Niklas
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    Malmös strategi för social hållbarhet med fokus på förorten2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    This report covers the social sustainability agenda in the suburbs Rosengård and Kroksbäck, situated in Malmö. These suburbs where constructed mainly in the years 1960-1975 and are now in need of refurbishing. There is also a housing shortage in Malmö and the demand is mainly for inexpensive apartments. Young adults, students, immigrants, senior citizens and families alike are looking for places where they can afford to live. The high demand for living space and the need of renovation could spark a gentrification process which would not be socially sustainable. The main actors whose social sustainability agendas are reviewed are the municipality of Malmö and the municipal owned housing company of MKB as well as the tenants’ association. The report also covers how the dialogue between the residents in Rosengård, the civil servants of the city and the landlords is carried out. Reactions from the residents in Rosengård have been researched in newspapers, but it proved hard to find while criminal reports where abundant. Lastly two examples on how the social sustainability agenda have been carried out in Gothenburg is presented. The methodology which the results are based on is a literature review.

    The report finds that both Malmö and Gothenburg are using a matrix formed decision tool in order to incorporate social aspects in all planning decisions. This is something which works well in both cities. The municipality of Malmö took a decision in 2014 that the social justice will increase when building new apartments. They do however realize the most of the newly constructed homes might be too expensive but they hope that this will eventually free up cheaper apartments. Different investment programs have been initiated in Rosengård, Rosengård I förvandling is one of them. Part of this program was based on local farming and different pedagogical activities. MKB are using social clauses when hiring different contractors, they stipulate that ten percent of the workforce should be locals or people who previously have been unemployed. This would be one the few tangible solutions which MKB is contributing with to solving the problem with lack of social sustainability. The tenants’ association is mainly focusing on minimizing the rent increase. They do however see a potential in so called neighborhood effects such as social learning were tenants are affecting other tenants in a positive way. The tennants’ association believes, as do the municipality of Malmö, that this can be achieved partly by constructing new houses among the older ones.

    The dialogue between the residents and the municipality used to be characterized as too little too late in the planning process. The revised aim with the dialogue is now to bring the citizens opinions into the decision process at an earlier stage. A potential problem could be the language barriers as there are many immigrants living in suburban Malmö. However in projects where the dialogue where given a priority the outcome became a success and the decision enjoys a broad support. As a recommendation for future research, a survey or deep interviews with the residents on their thoughts about actions taken to increase the social sustainability could be carried out. This is something which this report is lacking, good feedback from the residents. 

    Fulltekst (pdf)
    fulltext
  • 50.
    Andricciola, Antonio
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Development of an algorithm for the automatic adjustment of the heating curve of a heat pump heating system2018Independent thesis Advanced level (degree of Master (Two Years)), 5 hpOppgave
    Abstract [en]

    This work deals with the problem of choosing the correct heating curve for a certain building package (envelope plus distribution system). This topic is particularly relevant in countries like Sweden where heating curve is the most common way to control heat pumps. The analysis, involving four building models with respective distribution systems (two have floor heating and two radiators) and a variable speed GSHP, shows how, for a fixed location, the proper heating curve changes considering different building envelopes and different emitters. It is highlighted, therefore, how the adoption of a generic heating curve for all the buildings can cause discomfort and energy inefficiency. An algorithm to adjust the curve is then presented, and the results are compared with the reference case. The algorithm manages to improve comfort considerably and, for the A-class building, also SPF increases a lot (12.5%). The whole study was performed by means of TRNSYS® neglecting the DHW demand.

    Fulltekst (pdf)
    fulltext
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