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  • 1.
    Ackermann, Thomas
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Historical Development and Current Status of Wind Power2012Ingår i: Wind Power in Power Systems, Second Edition, John Wiley & Sons, 2012, s. 21-24Kapitel i bok, del av antologi (Refereegranskat)
    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.

  • 2.
    Ackermann, Thomas
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Wind Power in Power Systems2005Bok (Övrigt vetenskapligt)
    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.

  • 3.
    Ackermann, Thomas
    KTH.
    Wind Power in Power Systems, Second Edition2012Samlingsverk (redaktörskap) (Refereegranskat)
    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.

  • 4.
    Ackermann, Thomas
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Holttinen, H.
    Overview of Integration Studies - Methodologies and Results2012Ingår i: Wind Power in Power Systems, Second Edition, John Wiley & Sons, 2012, 2, s. 361-386Kapitel i bok, del av antologi (Refereegranskat)
  • 5.
    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 Systems2005Ingår i: Wind Power in Power Systems, John Wiley & Sons, 2005, s. 383-410Kapitel i bok, del av antologi (Övrigt vetenskapligt)
  • 6.
    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 Systems2012Ingår i: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, s. 293-327Kapitel i bok, del av antologi (Refereegranskat)
    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.

  • 7.
    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 Power2012Ingår i: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, s. 131-155Kapitel i bok, del av antologi (Refereegranskat)
    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.

  • 8.
    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 Frequency2012Ingår i: Wind Power in Power Systems, John Wiley & Sons, 2012, 2, s. 345-359Kapitel i bok, del av antologi (Refereegranskat)
    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.

  • 9.
    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 boreholes2013Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    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.

  • 10.
    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 exchangers2013Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 109, nr SI, s. 312-320Artikel i tidskrift (Refereegranskat)
    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.

  • 11.
    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, Ethiopia2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    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.

  • 12.
    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 Japan2018Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 175, s. 50-59Artikel i tidskrift (Refereegranskat)
    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.

  • 13.
    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 Energy2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Elektricitet är en grundläggande del av ett välfungerande samhälle. Ghanas elsystem påfrestas allt mer av skiftande klimat och växande befolkning. Därför är det oumbärligt för landets utveckling att elförsörjningen sker på ett hållbart sätt.

    Denna rapport syftar till att undersöka Ghanas förmåga att uppnå SDG 7.1 och Marrakech-visionen, vilken landet förband sig till under COP 22 mötet i Marocko. Detta genomfördes genom att utveckla en modell över Ghanas elsystem och dess utveckling, kallad BAU, med de digitala verktygen: OSeMOSYS och OnSSET. Därefter diskuterades dess genomförbarhet. Fortsatt undersöktes tre utvecklingsscenarier med olika mål för andel förnybar energi i elproduktionen, i modellen. Resultatet visar på att CSP och gaskraftverk var de mest framträdande elproducenterna. En stigande andel förnybar energi utspelade sig som en ökad elproduktion från vindkraftverk och minskad från gaskraftverk.

    Ghana besitter naturgastillgångar och hög solpotential. Den stigande andelen förnybar energi begränsar koldioxidutsläppen. Samtidigt kan den ökande andelen förnybar energi sätta pålitligheten i fråga då tillgången till sådan energi fluktuerar, och innebära höga investeringskostnader. Således kan BAU vara genomförbar sett till begränsning av koldioxidutsläpp, men kan eventuellt inte tillhandahålla tillförlitlig eller tillräcklig elektricitet. Att öka andelen förnybara energi i elproduktionen kan förbättra chanserna att nå SDG 7.1 men inte uppfylla målet helt.

  • 14.
    Aid, Graham
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi.
    Potential technology for the advanced utilization of construction, demolition, and industrial waste2008Konferensbidrag (Refereegranskat)
  • 15.
    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 applications2015Ingår i: Electrical Systems for Aircraft, Railway and Ship Propulsion, ESARS, IEEE , 2015Konferensbidrag (Refereegranskat)
    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.

  • 16.
    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 view2019Ingår i: International Journal of Engineering and Technology Innovation, ISSN 2223-5329, E-ISSN 2226-809X, Vol. 9, nr 2, s. 75-90Artikel, forskningsöversikt (Refereegranskat)
    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.

  • 17.
    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, sammanläggning (Övrigt vetenskapligt)
    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.

  • 18.
    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 (Övrigt vetenskapligt)
  • 19.
    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) (Övrigt vetenskapligt)
    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.

  • 20.
    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 Algorithms2014Ingår i: Proceedings of the World Sustainable Buildings Conference 2014, 2014Konferensbidrag (Refereegranskat)
  • 21.
    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
    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
    Royal Inst Technol KTH, Dept Energy Technol, S-10044 Stockholm, Sweden..
    Ghauri, Moinuddin
    COMSATS Univ Islamabad, Dept Chem Engn, Lahore Campus, Lahore 54000, Pakistan..
    Belova, Lyubov M.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Electrochemical study of composite materials for coal-based direct carbon fuel cell2018Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, nr 28, s. 12900-12908Artikel i tidskrift (Refereegranskat)
    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.

  • 22.
    Ali, Amjad
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Materialteknologi.
    Shehzad Bashir, F.
    Raza, Rizwan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Rafique, A.
    Kaleem Ullah, M.
    Alvi, F.
    Afzal, Muhammad
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Ghauri, M.
    Belova, Lyubov
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap.
    Electrochemical study of composite materials for coal-based direct carbon fuel cell2018Ingår i: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 43, nr 28, s. 12900-12908Artikel i tidskrift (Refereegranskat)
    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 LiNiCuZnFeO (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 °C, respectively. A maximum power density of 58 mWcm−2 is obtained using sub-bituminous fuel.

  • 23.
    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.2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    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. 

  • 24. 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 approach2016Ingår i: Computing, ISSN 0010-485X, E-ISSN 1436-5057, s. 1-15Artikel i tidskrift (Refereegranskat)
    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 %.

  • 25.
    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 reliability2012Ingår i: 9th International Conference on the European Energy Market, EEM 12, IEEE , 2012, s. 6254646-Konferensbidrag (Refereegranskat)
    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.

  • 26.
    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 Rules2015Ingår i: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 30, nr 1, s. 3-12Artikel i tidskrift (Refereegranskat)
    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.

  • 27. 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 region2018Ingår i: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 129, s. 70-80Artikel i tidskrift (Refereegranskat)
    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.

  • 28.
    Ancel, Julie
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Improvement of the electrical part of Idénergie's hydrokinetic turbine2014Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    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.

  • 29.
    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-projekt2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I denna rapport genomförs en studie med mål att identifiera mervärden i EPC-projekt genomförda i skolor för att öka intresset för EPC-projekt på marknaden. Rapporten undersöker hur planerat underhåll, tillsyn och skötsel samt felavhjälpande underhåll påverkas, hur försäkringspremier och villkor påverkas, hur inomhusmiljön och arbetsuppgifterna för driftpersonalen förändras. En litteraturstudie över energibesparingar, energianvändning i skolor, underhåll och försäkringar samt hur energieffektiviseringar relaterar till de svenska miljömålen har gjorts. Studiebesök har genomförts i Ludvika kommun, intervjuer har även genomförts med drifttekniker samt lokalstrateger i Ludvika och även anställda på försäkringsbolag.

    Skolor har ofta ett eftersatt underhåll, problem med ventilation och inomhusmiljö. Skolor har även en stor energieffektiviseringspotential på grund av deras låga nyttjandegrad, främst för att de står tomma delar av året. Alla Sveriges skolor skulle tillsammans kunna minska sin elanvändning med 1 TWh per år vilket i pengar motsvarar lönekostnaden för cirka 2000 lärartjänster.

    8 skolor i Ludvika kommun samt 10 skolor i Piteå kommun som har genomfört EPC-projekt har studerats. Tidsperioderna som studerats är sju år för Ludvika kommun, 2006 – 2012, och Piteå kommun fem år, 2010 – 2014. Data över felanmälningar och underhållskostnader har hämtats från kommunerna, och beskrivningar över skolorna samt EPC-projekten har erhållits från Caverion som har utfört EPC-projekten. Data för underhållet har till viss del valts ut i samråd med anställda på kommunerna.

    Antalet felanmälningar i Piteås skolor har visat på en svagt nedåtgående trend med en topp samtidigt som EPC-projektet genomfördes och ett år efter. Ludvika kommun har en uppåtgående trend för underhållskostnader, men detta beror troligtvis på sedan tidigare ackumulerat underhåll. Mängden felavhjälpande underhåll minskar, men först en tid efter projekten då man åtgärdat nyuppkomna fel och injusterat systemen. Arbetsuppgifterna relaterade till tillsyn och skötsel ändras då fjärrstyrning av systemen installeras vilket leder till en bättre överblick och förenklar felsökning. Inomhusklimatet blir även jämnare, men först efter att bristerna som framkommit i samband med driftoptimeringen åtgärdats. Dock finns det klagomål i Ludvika om låga temperaturer, men detta grundar sig i att kommunen satt för låg rikttemperatur. Försäkringar påverkas marginellt, och först när skadeförebyggande åtgärder genomförs i fastigheter, vilket inte är något som gjorts i de studerade fastigheterna. Dock är underlaget för litet och i båda fall över för få år för att kunna påvisa säkra förändringar.

    Ett mervärde som identifierats är möjligheten att använda EPC-projekt som ett verktyg för att åtgärda eftersatt underhåll inom fastighetsbeståndet utanför de normala budgetramarna och samtidigt uppnå en energibesparing. 

  • 30.
    Andersson, Elin
    KTH, Skolan för industriell teknik och management (ITM), Industriell ekologi.
    Use cases and Business Models: Urban Smart Grid2011Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    EU har upprättat ett klimat- och energipaket som innehåller lösningar på de hotandeklimatförändringarna. Det kallas 202020- paketet och det har som mål att växthusgaserna ska reduceras med 20 % till år 2020, att energianvändningen bör sänka smed 20 % och energieffektiviteten ska vara 20 % högre.

    Norra Djurgårdsstaden är en stadsdel i Stockholm som till viss del utvecklas efter dessa mål. Vision för Norra Djurgårdsstaden är att utveckla en levande och hållbar stadsdel i världsklass som bör bidra till innovation, utveckling och marknadsföring av den svenska miljöteknikssektorn. Detta examensarbete fokuserar främst på eko-effektiva transporter och energianvändning. Genom ett nytt och mer effektiv nät, Smart Grid, ska den totala energianvändningen sänkas, lasterna optimeras, det ska finnas möjligt att ansluta närproducerad el samt att integrera elfordon. För att göra introduktionen av Smart Grid så smidigt som möjligt har användarfall utnyttjats i förarbetet. Ett användarfall är ett dokument som består av ett eller flera scenarier och det beskriver hur en aktör, människa eller hårdvara, interagerar med systemet för att nå ett specifikt mål.

    Detta examensarbete har utförts på uppdrag av Fortum och syftet med studien var att leverera idéer och förslag på marknads- och affärsmodeller samt att finna nya incitament för kunderna då detta kommer att behövas för att lyckas med att implementera Smart Grid. Arbetet kommer att utföras med särskild hänsyn till hållbarutveckling. 170 befintliga användarfall sorterades utifrån vilket område i det nya nätet som de beskrev. Detta gjordes så att ett område inom Norra Djurgårdsstaden kunde väljas ut för att vara genomgå en djupare analys. De användarfall som handlade om integration och användning av elbilen valdes ut för att studeras närmare. Detta gjordes för att utvärdera vilka förändringar som krävs i styrning, reglering etc., för att lyckas i utvecklingen med det nya nätet. I och med detta fick examensarbetet ett nytt syfte, att visa de skillnader som finns i koldioxidutsläpp och kostnader mellan elbilen och en vanlig bil. I denna studie antas utsläppen från elbilen vara lika med de utsläpp som uppkommer i samband med elproduktionen. Timspecifika utsläpp beräknades medhjälp av historisk elproduktionsdata kombinerad med en prognos för elproduktionsmixen år 2020. Resultatet av beräkningarna skiljer sig åt beroende på om fordonet "använder" sig av den totala produktionsmixen eller endast marginalel. De tvåbilar som jämförts kommer båda från Renault. Resultatet visar att elbilen betalar en tredjedel mindre i skatter än den vanliga bilen. Tittar man på de totala kostnaderna så har investeringen i elbilen en återbetalningstid, då kostnaderna är lika med de för den vanliga tiden, på tio år. Ersätts en dieselbil med en elbil är sänkningarna i koldioxid mellan 0,54 och 1,67 ton per år. Tillsammans pekar detta på att en differentierad koldioxidskatt skulle gynna elbilen och tvinga till att man betalar för det som man släpper ut.

  • 31.
    Andersson, Niklas
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    Malmös strategi för social hållbarhet med fokus på förorten2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Den här rapporten behandlar olika aktörers bidrag till den sociala hållbarheten i Malmös förorter. Dessa förorter byggdes mellan åren 1960-1975 och är nu i stort behov av upprustning. Samtidigt lider Malmö av en stor bostadsbrist och det är främst bostäder med låga hyror som efterfrågas. Ungdomar, studenter, invandrare, pensionärer och familjer letar efter bostäder som de har råd med. Stor efterfrågan på bostäder och ett stort renoveringsbehov kan innebära en gentrifiering som inte är socialt hållbar. De aktörer vilkas sociala hållbarhetsarbete har undersökts är Malmö stad, det kommunala bostadsbolaget MKB samt hyresgästföreningen. Dessa är organisationer som har en stor möjlighet att påverka agendan runt den sociala hållbarheten i Malmös förorter. Vidare undersöker rapporten också på hur arbetet med medborgardialog ser ut samt vilka reaktioner olika satsningar fått från de boende. Slutligen så redovisas två erfarenheter från Göteborgs miljonprogramsområden. Rapporten baseras på en litteraturstudie.

    Undersökningen visar att både Malmö och Göteborg jobbar med en form av matrissystem för att säkerställa att den sociala hållbarheten inkluderas i planfrågor och har visat sig fungera bra i båda städerna. Malmö kommun tog 2014 ett beslut om att social rättvisa ska vara vägledande vid nybyggnation av flerfamiljshus. Det finns en insikt i att många nybyggda lägenheter kan bli dyra men förhoppningen är att detta ska frigöra billigare bostäder. Olika investeringsprogram har sjösatts i Rosengård där Rosengård i förvandling är ett exempel. Delar av detta program fokuserar på olika pedagogiska aktiviteter och stadsodling och en bieffekt har blivit att människor har fått en mer positiv syn på Rosengård. MKB fokuserar sitt sociala hållbarhetsarbete på sociala klausuler för underleverantörer där målet är att tio procent av arbetarna ska vara bosatta i området eller tidigare arbetslösa. Hyresgästföreningens fokus ligger på att hålla hyreshöjningarna på en så låg nivå som möjligt men de ser också en potential med såkallade grannskapseffekter, där boende påverkar andra boende på ett positivt sätt. Hyresgästföreningen och Malmö stad tror att detta är något som delvis kan uppnås genom att bygga nya flerbostadshus bland äldre bebyggelse.

    Medborgardialogen har tidigare karakteriserats av att den varit fokuserad på att informera de boende om olika beslut. Det nya målet med medborgardialogen är att det ska föra in de boendes åsikter som en aktiv del i beslutsprocessen i ett tidigt stadium. Ett potentiellt problem är de språkbarriärer som kan uppstå i ett så multikulturellt samhälle som Malmö. Erfarenheter visar dock på goda resultat i projekt där medborgardialogen prioriterats. Det visade sig problematiskt att finna reaktioner från de boende som är kopplade till de olika initiativen som syftar öka den sociala hållbarheten. Genomförandet av en sådan studie med hjälp av enkäter eller djupintervjuer är ett förslag för att nå ökad kunskap och ett förslag på fortsatt forskning inom området. 

  • 32.
    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 system2018Självständigt arbete på avancerad nivå (masterexamen), 5 hpStudentuppsats (Examensarbete)
    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.

  • 33. Angioni, A.
    et al.
    Hooshyar, Hossein
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Vanfretti, Luigi
    KTH, Skolan för elektro- och systemteknik (EES), Elkraftteknik.
    Garcia, C.C.
    et al.,
    A distributed automation architecture for distribution networks, from design to implementation2018Ingår i: Sustainable Energy, Grids and Networks, ISSN 0284-4354, E-ISSN 2352-4677, Vol. 15, s. 3-13Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    With the current increase of distributed generation in distribution networks, line congestions and PQ issues are expected to increase. The smart grid may effectively coordinate DER, only when supported by a comprehensive architecture for automation. In IDE4L project such architecture is designed based on monitoring, control and business use cases. The IDE4L instance of SGAM architecture is derived and explained in details. The automation actor are specified in terms of interfaces, database and functions. The division in these three layers boosted the implementation phase as dedicated interfaces, databases or application has been developed in a modular way and can be installed in different HW/SW. Some implementation instances are presented and the main output of the architecture is discussed with regards to some indexes as communication traffic and level of distribution of automation functions.

  • 34.
    Anglart, Henryk
    et al.
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnenergiteknik.
    Li, Haipeng
    KTH, Skolan för teknikvetenskap (SCI), Fysik, Kärnenergiteknik.
    Niewinski, Grzegorz
    Warsaw Univ Technol, Inst Heat Engn, Nowowiejska 21-25, PL-00665 Warsaw, Poland..
    Mechanistic modelling of dryout and post-dryout heat transfer2018Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 161, s. 352-360Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this paper a new mechanistic model for the diabatic annular two-phase flow is presented and applied to prediction of dryout and post-dryout heat transfer in various channels. The model employs a computational fluid dynamics code - OpenFOAM (R) - to solve the governing equations of two-phase mixture flowing in a heated channel. Additional closure laws have been implemented to calculate the location of the dryout and to predict wall temperature in the post-dryout region. Calculated results have been compared with experimental data obtained in pipes and good agreement between predictions and measurements has been achieved. The presented model is applicable to complex geometries and thus can be used for prediction of post-dryout heat transfer in a wide variety of energy conversion systems.

  • 35. Anh, N. T.
    et al.
    Van Hertem, Dirk
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem. K.U. Leuven, Belgium .
    Driesen, J.
    Transient stability enhancement by TCSC controllers using remote input signals2010Ingår i: 2010. ACDC. 9th IET International Conference on AC and DC Power Transmission, 2010, nr 570 CPKonferensbidrag (Refereegranskat)
    Abstract [en]

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

  • 36. Aoun, M. -C
    et al.
    Pešut, D.
    Matosović, M.
    Bošnjak, R.
    Deane, P.
    Glynn, J.
    Gallachóir, B. Ó
    Nagy, S.
    Badouard, T.
    Desbrosses, N.
    Taliotis, Constantinos
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energisystemanalys.
    de Boncourt, M.
    Keramidas, K.
    Gas Security of Supply in the European Union2017Ingår i: Europe's Energy Transition: Insights for Policy Making, Elsevier, 2017, s. 67-78Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

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

  • 37.
    Arias Hurtado, Jaime
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Tillämpad termodynamik och kylteknik.
    Whole Supermarket System Modelling2015Ingår i: Sustainable Retail Refrigeration, Wiley Blackwell , 2015, s. 263-290Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

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

  • 38.
    Arjmand, Mehdi
    et al.
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik.
    Liu, Longcheng
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Neretnieks, Ivars
    KTH, Skolan för kemivetenskap (CHE), Kemiteknik, Kemisk apparatteknik.
    Exergetic efficiency of high-temperature-lift chemical heat pump (CHP) based on CaO/CO2 and CaO/H2O working pairs2013Ingår i: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 37, nr 9, s. 1122-1131Artikel i tidskrift (Refereegranskat)
    Abstract [en]

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

  • 39.
    Arnaudo, Monica
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Zaalouk, O. A.
    Topel, Monika
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Laumert, Björn
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Techno-economic Analysis of Integrated Energy Systems at Urban District Level - A Swedish Case Study2018Ingår i: Energy Procedia, Elsevier, 2018, s. 286-296Konferensbidrag (Refereegranskat)
    Abstract [en]

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

  • 40.
    Arvanitis, Konstantinos
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    MACROALGAE IN THE BIOREFINERY: A SUBSTANCE FLOW ANALYSIS AND ENVIRONMENTAL ASSESSMENT OF AN EXTRACTION PROCESS OF THE MAJOR COMPONENTS IN SACCHARINA LATISSIMA2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

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

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

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

  • 41.
    Asef, Pedram
    et al.
    Univ Politecn Cataluna, BarcelonaTech, Dept Elect Engn, EEBE, Barcelona 08019, Spain..
    Bargallo Perpina, Ramon
    Univ Politecn Cataluna, BarcelonaTech, Dept Elect Engn, EEBE, Barcelona 08019, Spain..
    Barzegaran, M. R.
    Lamar Univ, Renewable Energy Microgrid Lab, Beaumont, TX 77705 USA..
    Lapthorn, Andrew
    Univ Canterbury, Dept Elect & Comp Engn, Christchurch 8041, New Zealand..
    Mewes, Daniela
    KTH, Skolan för industriell teknik och management (ITM).
    Multiobjective Design Optimization Using Dual-Level Response Surface Methodology and Booth's Algorithm for Permanent Magnet Synchronous Generators2018Ingår i: IEEE transactions on energy conversion, ISSN 0885-8969, E-ISSN 1558-0059, Vol. 33, nr 2, s. 652-659Artikel i tidskrift (Refereegranskat)
    Abstract [en]

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

  • 42.
    Ast, Eric
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    The state of long-term climate action planning in megacities: Planning and demographic trends among 17 of the world’s leading cities aiming to reduce emissions by 80% by the year 20502015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

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

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

  • 43.
    Awan, Muhammad Rizwan
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Kraft- och värmeteknologi.
    Feasibility Study of Vertical Axis wind turbines in Urban areas of Sweden2013Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 44.
    Awan, Muhammad Rizwan
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik.
    Riaz, Fahid
    Nabi, Zahid
    Analysis of conditions favourable for small vertical axis wind turbines between building passages in urban areas of Sweden2017Ingår i: International Journal of Sustainable Energy, ISSN 1478-6451, E-ISSN 1478-646X, Vol. 36, nr 5, s. 450-461Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents the analysis of installing the vertical axis wind turbines between the building passages on an island in Stockholm, Sweden. Based on the idea of wind speed amplification due to the venture effect in passages, practical measurements were carried out to study the wind profile for a range of passage widths in parallel building passages. Highest increment in wind speed was observed in building passages located on the periphery of sland as wind enters from free field. Wind mapping was performed in the island to choose the most favourable location to install the vertical axis wind turbines (VAWT). Using the annual wind speed data for location and measured amplification factor, energy potential of the street was calculated. This analysis verified that small vertical axis wind turbines can be installed in the passage centre line provided that enough space is provided for traffic and passengers.

  • 45. Aziz, M.
    et al.
    Zaini, Ilman Nuran
    KTH, Skolan för industriell teknik och management (ITM), Materialvetenskap, Energi- och ugnsteknik.
    Production of hydrogen from algae: Integrated gasification and chemical looping2017Ingår i: Proceedings of the 9th International Conference on Applied Energy, Elsevier, 2017, Vol. 142, s. 210-215Konferensbidrag (Refereegranskat)
    Abstract [en]

    Due to their high potential and beneficial characteristics, algae is considered as very promising energy source in future. In this study, an integrated conversion system of algae to hydrogen is proposed with the objective of high total energy conversion efficiency. The proposed system mainly covers algal drying, gasification, and chemical looping. To facilitate optimum heat circulation throughout the proposed system, enhanced process integration is adopted. It combines exergy recovery and process integration technologies in order to achieve a wasted energy, hence the total energy efficiency can be improved significantly. In the proposed system, to convert algae to hydrogen, steam gasification and syngas chemical looping are integrated as the main conversion. Iron oxide is employed as the oxygen carrier, and is circulated among the reactors in the chemical looping module. Process modeling and calculation is performed using ASPEN Plus, and the total energy efficiency, including hydrogen production and power generation, is evaluated. Several operating parameters including target moisture content in drying, steam-to-biomass ratio in gasification, and chemical looping pressure, are observed. From the results, it is shown that the proposed system is potential to convert algae to hydrogen with high total energy efficiency, which is higher than 70%. Both target moisture content and steam-to-biomass ratio influence strongly the total energy efficiency. On the other hand, chemical looping pressure show insignificant effect to total energy efficiency.

  • 46.
    Bakhiet, Omnia
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi. KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande.
    Mustafa, Riham
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi. KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Fastigheter och byggande.
    Biogas Production in Abu Dhabi: An Evaluation based on Energy and Economy (Comparison of two plant designs)2015Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Abu Dhabi, huvudstaden för Förenade Arab Emiraten, är kända för deras snabba utveckling under en kort period. Staden generar mycket avfall dagligen och detta deponeras oftast. Den organiska delen av hushållsavfall som deponeras bidrar till utsläpp av växthusgaser och cirka 80 % av detta organiska avfall deponeras i Abu Dhabi. Staten i Abu Dhabi har visat engagemang för att minska utsläppen av växthusgaser genom att försöka generera 7 % förnybar energi, förbättra avfallshanteringen, och utveckla en strategi för "grön ekonomi". I denna studie undersöks biogassystemet som utnyttjar rötning av den organiska delen av hushållsavfall för sin produktion av biogas. Moduler baserade på två olika kraftanläggningar, Aikan® och REnescience®, simulerades med hjälp av programvaran SuperPro Designer®. Värden för energiåtgång och ekonomiska storheter erhölls och användes för beräkningar i arbetet.

    Energikvot är ett begrepp som används för att beräkna hur effektiv ett bränsle är genom att dividera energin som ges med energin som behövs i en process. De två olika modulerna ger energikvot (EROI) värden för elektricitet som nästan fördubblas i båda fallen. Tre metoder användes för att beräkna lönsamheten av modulernas lönsamhet, ”internal rate of return, pay- back period ” och Nuvärdesmetoden ”NPV”. Nuvärdesmetoden ansågs vara mest pålitlig och en NPV av 500 000 $ respektive 3 000 000 $ ficks för modulerna. Dessa resultat visar att genomförandet av ett biogassystem kommer ge ett mycket litet bidrag för att uppnå Abu Dhabis mål på 7 % förnybar energi till och med år 2030. Däremot minskas utsläpp av växthusgaser, avfallshanteringen förbättras samt bidrar till en grönare ekonomi. 

  • 47. Balram, Pavam
    et al.
    Tuan, Le Anh
    Bertling Tjernberg, Lina
    KTH, Skolan för elektro- och systemteknik (EES), Elektroteknisk teori och konstruktion.
    Centralized charging control of plug-in electric vehicles and effects on day-ahead electricity market price2015Ingår i: Plug In Electric Vehicles in Smart Grids, Springer, 2015, s. 267-299Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Global policy targets to reduce greenhouse gas emissions have led to increased interest in plug-in electric vehicles (PEV) and their integration into the electricity network. Existing electricity markets, however, are not well suited to encourage direct participation of flexible demand from small consumers such as PEV owners. The introduction of an aggregator agent with the functions of gathering, aggregating, controlling and representing the energy needs of PEV owners in the electricity market could prove useful in this regard. In this chapter, a mathematical model of PEV aggregator for participation in the day-ahead electricity market is described. The modeling is done by treating each of the individual vehicle batteries as a single large battery. The centralized charging and discharging of this battery is then scheduled based on the traveling needs of the PEV owners determined by an aggregated driving profile and the cumulative electrical energy needs of vehicles over the optimization horizon. Two methods for scheduling PEV demand named as joint scheduling method (JSM) and aggregator scheduling method (ASM) are presented. The two methods are subsequently used to observe the effects of introducing flexible scheduling of PEVs on the day-ahead market price in an IEEE test system and a Nordic test system. Results from the IEEE test system case studies will indicate that the scheduling of PEV energy through direct centralized control at high PEV penetration levels of 50 % or greater could lead to potential lowering of day-ahead market prices as compared to an indirect control method such as the use of fixed period charging. Results from the Nordic test system case study shows that controlled scheduling of PEV demand could lead to only a small increase in day-ahead market price of electricity.

  • 48.
    Baradar, Mohamadreza
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Hesamzadeh, Mohammad R.
    KTH, Skolan för elektro- och systemteknik (EES), Elektriska energisystem.
    Calculating Negative LMPs from SOCP-OPF2014Ingår i: ENERGYCON 2014 - IEEE International Energy Conference, IEEE Computer Society, 2014, s. 1461-1466Konferensbidrag (Refereegranskat)
    Abstract [en]

    Recent research shows that non-convex OPF problem can be recast as a convex Semidefinite Programming (SDP) problem or Second Order Cone Programming (SOCP) problem. However, in the most SOCP OPF problems, there are some cases that conic relaxation results in a miscalculation of negative Local Marginal Prices (LMPs). This paper reviews the SOCP formulation of the optimal power flow problem proposed in [1] and then proposes one way of generating negative Locational Marginal Prices, LMPs, using this SOCP formulation. The proposed model is coded in GAMS and its built MOSEK solver and tested on a modified version of IEEE-30 test system.

  • 49.
    Barragán-Beaud, Camila
    et al.
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energi och klimatstudier, ECS. Department of Mechanical Engineering, Aalto University, School of Engineering, Aalto, Finland.
    Pizarro-Alonso, A.
    Xylia, Maria
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energi och klimatstudier, ECS.
    Syri, S.
    Silveira, Semida
    KTH, Skolan för industriell teknik och management (ITM), Energiteknik, Energi och klimatstudier, ECS.
    Carbon tax or emissions trading?: An analysis of economic and political feasibility of policy mechanisms for greenhouse gas emissions reduction in the Mexican power sector2018Ingår i: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 122, s. 287-299Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This study provides a comparative assessment of carbon-pricing instruments for the Mexican electricity sector, contrasting a carbon tax with an emissions trading scheme (ETS). The assessment is performed in terms of economic impacts and political feasibility. Model-based scenarios considering different price and quantity levels are analyzed on Balmorel-MX, a cost optimization bottom-up model of the Mexican electricity system. The political feasibility is evaluated using an online survey and interviews with representatives of relevant stakeholder groups. The assessment suggests that an ETS is the most appropriate instrument for the Mexican case. We recommend to set the cap as 31% abatement in relation to a baseline, which is suggested to be 102 MtCO2 by 2030, given the business-as-usual baseline used as reference by the Mexican government (202 MtCO2) is found to leave cost-effective abatement potential untapped. An emission trading system with such design has higher cost-efficiency and lower distributional effects than a carbon tax at equivalent ambition level (15 USD/tCO2). The political feasibility analysis confirms the assessment, as it is in line with the priorities of the stakeholder groups, allows earmarking carbon revenue and avoids exempting natural gas from carbon pricing.

  • 50.
    Barås, Madeleine
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Hållbar utveckling, miljövetenskap och teknik, Industriell ekologi.
    Assessing the environmental sustainability of an apparel supply chain: the development of a conceptual model based on a comparative study of preferred tools and actual practices2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The apparel and textile industry is one of the largest in the world and is characterised by complex, global supply chains, water and chemical intensive processes as well as environmentally harmful raw material extraction and production. Because of this, environmental sustainability has become a key issue for the businesses in recent years. With this in mind, and considering an increasing demand for textile and apparel goods, the industry is in urgent need of improving the environmental footprint of its products. However, lack of transparency and available data throughout apparel supply chains decrease chances of producing accurate sustainability assessments, which in turn obstruct improvement measures. Moreover, companies often lack the in-house competence required to manage and create strategies for sustainability assessments.

    In this study an overview of an apparel supply chain is provided, highlighting phases, sub phases, input and environmental indicators. Appropriate tools for assessing the environmental sustainability of such a supply chain are inventoried and examined. Based on a case study, a literature review and a stakeholder opinion assessment, misalignments between actual practices within an apparel company and recommended practices of the researcher and stakeholder communities are uncovered. These identified misalignments enabled the development of a conceptual model, aiming at facilitating the process of developing an environmental sustainability assessment strategy within an apparel company. 

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