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  • 101.
    Allard, Ingrid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Hassan, Osama A. B.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Methods for energy analysis of residential buildings in Nordic countries2013In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 22, p. 306-318Article, review/survey (Refereed)
    Abstract [en]

    To meet the goals of the directive 2010/31/EU on the energy performance of buildings, the building sector in Europe now faces a transition towards more energy efficient buildings. Research and development of new energy solutions and technology will be necessary for the transition and the importance of analyzing building energy performance increases. This paper aims to review and evaluate different methods that are commonly used to analyze energy performance in residential buildings in Nordic countries, primarily in Sweden, Norway and Finland. A short international review of regulations is also included. The goal is to find commonly used methods and possibilities for the future. The introduced methods are summarized, categorized and compared based on their advantages and disadvantages. Although the three Nordic countries have similar climate conditions and building traditions, the review shows relatively large variations in the definitions of energy performance for residential buildings, as well as variations in how measurements and calculations are used in the methods for energy performance analysis. In the conducted review, methods, or parts of methods, are also found to be used. The methods used to analyze energy performance are found to be more similar than the concepts of energy performance itself in the three countries. These aspects may be considered in further work to develop an international policy practice for energy performance of residential buildings in cold climate.

  • 102.
    Allard, Ingrid
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nair, Gireesh
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energy performance indicators in the Swedish building procurement process2017In: Sustainability, E-ISSN 2071-1050, Vol. 9, no 10, article id 1877Article in journal (Refereed)
    Abstract [en]

    In Sweden, all new buildings need to comply with the National Board of Housing, Building and Planning’s requirement on specific purchased energy (kWh/m2). Accordingly, this indicator is often used to set design criteria in the building procurement process. However, when energy use is measured in finished buildings, the measurements often deviate significantly from the design calculations. The measured specific purchased energy does not necessarily reflect the responsibility of the building contractor, as it is influenced by the building operation, user behavior and climate. Therefore, Swedish building practitioners may prefer other indicators for setting design criteria in the building procurement process. The aim of this study was twofold: (i) to understand the Swedish building practitioners’ perspectives and opinions on seven building energy performance indicators (envelope air leakage, U-values for different building parts, average U-value, specific heat loss, heat loss coefficient, specific net energy, and specific purchased energy); and (ii) to understand the consequences for the energy performance of multi-family buildings of using the studied indicators to set criteria in the procurement process. The study involved a Delphi approach and simulations of a multi-family case study building. The studied indicators were discussed in terms of how they may meet the needs of the building practitioners when used to set building energy performance criteria in the procurement process.

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  • 103.
    Allard Stolterman, Ingrid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Regulating energy performance of residential buildings in cold climate: a study of indicators, criteria, and evaluation methods2021Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Building energy performance has been important in Fennoscandia ever since the early vernacular houses, to combat the cold climate. Due to EU directive 2010/31/EU on the energy performance of buildings (EPBD recast), building energy performance has become even more relevant in northern Europe the last decade. Objectives for improving building energy performance may include reducing cost and CO2-emissions, increasing energy independency, and improving the indoor climate. Different indicators, criteria, and evaluations methods may be used to reach these objectives. This dissertation addresses indicators, criteria, and evaluation methods used to regulate energy performance of residential buildings in Sweden, Norway, Finland, and Russia. Four research objectives are covered: (RO1) comparing criteria and evaluation methods used to regulate energy performance of residential buildings in Sweden, Norway, and Finland, (RO2) studying the perspective of professionals with experience in building energy performance evaluation on (a) methods for evaluating envelope air leakage of residential buildings in Sweden and Finland and (b) potential energy performance indicators in the Swedish procurement process of multi-family buildings, (RO3) developing an approach for analysing the performance gap between design predictions and measurements that can be used to verify compliance with requirements on building energy use in practice, and (RO4) comparing the stringency of the energy performance criteria for residential buildings between the Swedish, Norwegian, Finnish, and Russian national building code. Many differences were found between how energy performance of residential buildings was regulated in the four countries. In Sweden, measurements were used more for evaluating building energy performance than in the other countries. As of 1st January 2020, the Finnish building code was characterized by its focus on the building heat loss and stringent energy performance criteria compared to the other countries. The Norwegian building code was characterized by a relatively narrow system perspective on energy performance, with no regulation of the energy production efficiency or energy source. The Russian building code also had a narrow system perspective but was also characterized by its focus on the form factor – the relationship between building volume and enclosing area. The practitioners wanted to minimize the influence from building operation and user behaviour on energy performance evaluations in the Swedish building procurement process of multi-family buildings. Hence, they preferred component-focused indicators or indicators with a narrow system boundary. An approach has been developed for analyzing the performance gap between design phase predictions and measurements. The approach can be used to verify the finished building’s energy performance, with minimal influence from occupant behavior and building operation.

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  • 104.
    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, School of Industrial Engineering and Management (ITM), Energy Technology.
    Usher, William
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems.
    Taliotis, Constantinos
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology. Cyprus Inst, Nicosia, Cyprus..
    Sundin, Caroline
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Sridharan, Vignesh
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    Ramos, Eunice
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology.
    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)2022In: Data in Brief, E-ISSN 2352-3409, Vol. 42, p. 108021-, article id 108021Article in journal (Refereed)
    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.

  • 105.
    Almered Olsson, Gunilla
    et al.
    Norges Teknisk-Naturvitenskapelige Universitet, Trondheim, Norge.
    Bladh, GabrielKarlstad University, Division for Social Sciences.Månsson, BengtKarlstad University, Division for Engineering Sciences, Physics and Mathematics.Nyberg, LarsKarlstad University, Division for Environmental Sciences.
    Inte bara träd: hållbart mångbruk av skogslandskapet2004Collection (editor) (Refereed)
    Abstract [sv]

    Skogslandskapen - hur skall vi värdera dem? Ska de betraktas som rekreationsområden och kulturlandskap eller som arena för konflikter och dragkamp om olika resurser? Är skogsregionerna närande eller tärande? Vilka viktiga samband finns mellan skandinaviska och tropiska landskap?Detta är några av de teman som behandlas i denna spänannde bok om de många dimensionerna och resurserna som ryms i skogslandskapen. Boken ger nya och stimulerande aspekter på framtidsmöjligheterna för en hållbar utveckling för boreala skogslandskap. Den tar också upp det nödvändiga mångbruket av skogens resurser liksom den förändrade synen på människans roll i skogen. Och inte minst behandlas den ekologiska paradoxen att störningar behövs för att bevara skogens ekologiska mångfald.Boken är författad av samhällsvetare, miljöteknologer och ekologer inom den tvärvetenskapliga forskargruppen MiljöFocus vid Karlstads universitet.

  • 106.
    Almgren, Mattias
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Effekten av dagsljus- och närvarostyrd LED-belysning i en befintlig kontorsbyggnad ur energi-, ekonomi- och ljusmiljösynpunkt2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An important measure to reduce buildings’ environmental impact is to make the artificial lighting more effective, which is the biggest electricity consumer of Swedish office buildings and accounts for more than 30 % of the total electricity consumption.A case study has been carried out in this master thesis as a part in an existing project with ÅF Lighting, where new strategic avenues has been explored in which to combine day- and electrical light in office landscapes in a smarter, more energy-efficient manner and at the same time improve the lighting environment.Two office spaces at the own head office of ÅF in Solna, Stockholm has been used in the case study, where two different LED lighting solutions got installed. One with pendant luminaries, desk lamps and downlights, and one with only recessed luminaires.Through several computer simulations, electricity and light measurements, questionnaires, interviews etc., it has been investigated how the heat and cooling load, electricity consumption, lighting quality and operating costs has been affected of the change of the lighting system. The lighting environment, daylight conditions, heat and cooling load, economical savings and electricity consumption for the two offices has been investigated in diaLUX, DIVA-for-Rhino, IDA ICE 4.7, ecoCALC and Mitec Monitor, respectively. The electricity measurements showed that the lighting solutions’ electricity consumption got reduced with 71,6 % on floor 5 and 68,1 % on floor 10 with the new LED lighting solutions and control systems during the investigated month.Through the IDA ICE energy simulations over a year it was shown that the total yearly cooling load to floor 5 and floor 10 got reduced with 19 % and 17 %, which can be explained by the lesser heat gain from the more energy efficient lighting and the controlling of this. Though a small increase in heating load, the total energy consumption got reduced with around 12-14 % on both floors. The simulations also showed that the total electricity consumption of the lighting got reduced with 70 % for floor 5 and 63 % for floor 10 after the change to the new LED lighting solutions and implementation of control systems.The LCC for the new lighting solutions showed that these have a higher investment cost than the total operation cost for the existing solution over the life cycle. However, the costs to run the LED solutions are less than a third of the operation costs for the existing solution, and after the exchange the carbon dioxide emissions can be reduced with close to 70 %.Through this case study it has been shown that the energy consumption from lighting can be highly reduced with the installation of energy efficient lighting in combination with smart control systems, and it can also have a positive effect on the lighting environment. However, the high investment costs of the LED solutions lead to the conclusion that installation of these solutions today is not economically justifiable.

  • 107.
    Al-Mimar, Samer
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science. Halmstad University.
    Integration of solar and wind power at Lillgrundwind farm.: Wind turbine shadow effect on solar farm atLillgrund wind farm.2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The supply of energy is a key factor in modern societies. As the old fossil sources for energy are dwindling, conflicts arise between competing nations and regions. Fossil energy sources also contribute to the pollution of the environment and emission of greenhouse gases.

    With renewable energy sources many of these drawbacks with fossil fuels can be eliminated as the energy will be readily available for all without cost or environmental impact.

    Combining the renewable energy sources will be very effective, particularly in commercial areas where lake of electricity is high. The cost of combining onshore wind and solar power plant is affordable. Furthermore there is no power failure or load shedding situation at any times. When it is manufactured in a large scale, cost of this integrated natural resources power generation system is affordable. Moreover there is no power failure or load shedding situation at any times. Therefore, it is the most reliable renewable power or electricity resources with less spending and highly effective production. ref [1].

    The thesis work would take planning of offshore renewable plant (Lillgrund) with considering the resources of renewable power. The study would take in account combining the Lillgrund wind farm with solar system and take close look into the advantage and disadvantage of combining the renewable resources together and figure out if such station can work in proper way and provide sufficient power production. The study would take in account the effect of each resource on other resource, also calculations would be done.

    The study site is Lillgrund in south of Sweden. The Lillgrund wind farm is the most important offshore wind power plant installed in Sweden with a total capacity of 110 MW, corresponding to 48 turbines. ref [2].

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    Integration of solar and wind power at Lillgrund wind farm.
  • 108. Al-Moathin, Ali Hussain Hassan
    Modeling of Photovoltaic Power System2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 109.
    Almstedt, Kalle
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektiviseringsåtgärder på Gustavsvik resorts AB2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Badhus är den typ av svenska lokaler som använder mest energi, ofta med en energiprestanda som är långt högre än BBRs gränsvärden för ny- och ombyggnationer. Denna rapport är resultatet av ett examensarbete för Civilingenjörsprogrammet i energiteknik vid Umeå Universitet. Det har utförts på uppdrag av teknikkonsultföretaget KAMTechnology AB åt upplevelseanläggningen Gustavsvik resorts AB. Gustavsvik ligger i Örebro och består av bland annat äventyrsbad, motionsbad, gym, camping med mera. Detta examensarbete syftar till att utreda möjligheter och ta fram förslag till energieffektiviseringsåtgärder för Gustavsviks badanläggning. Studien har avgränsats till att behandla energisystemet för kyla och värme med fokus på kylkretsen och värmeåtervinning ur gråvatten.

    Potentialen för värmeåtervinningen ur Gustavsviks gråvatten har beräknats till cirka 130 000 kWh/år, vilket utgör ca 20 % av deras köpta energi för varmvattenberedning. Det finns en handfull produkter på marknaden för värmeåtervinning ur grå- och avloppsvatten, som hävdar god prestanda och lönsamma installationer. Det kan konstateras att det finns få utförda studier och genomförda projekt som presenterar mätvärden och prestanda för dessa typer av installationer. Intresset för dessa typer av anläggningar tycks ändå öka och branschorganisationer försöker skynda på utvecklingen genom bland annat tekniktävlingar vilket sammanfattas i, och styrks, av litteraturstudien som utgör en del av denna rapport.

    Platsbesök har utförts för att samla in data från anläggningens styr- och övervakningssystem. Insamlad data har loggats under 2013 och utgörs av temperaturer, flöden samt el- och fjärrvärmeanvändning. Kompletterande mätningar av kyl- och värmebärarens flöde utfördes även för att kunna uppskatta värmepumparnas kyl- och värmeproduktion En begränsad kartläggning av Gustavsviks kylkrets har utförts, där även anläggningens två värmepumpar har utvärderats. Värmepumparnas prestanda visade sig vara sämre än vad tillverkarna uppger och det finns därmed en möjlig besparingspotential i att förbättra och optimera deras drift. Datahanteringen och beräkningar har främst gjort i Microsoft Excel. Under examensarbetet har det identifierats flera fall där man kyler och värmer på samma ställe, vilket betraktas som möjligheter till energieffektiviseringsåtgärder. Slutsatserna av denna studie är att Gustavsvik har stora möjligheter till att sänka sin energiförbrukning. Detta genom att bland annat installera värmeåtervinning ur gråvatten, bygga bort konkurrerande värme och kyla samt att justera in sitt energisystem. Det som Gustavsvik rekommenderas att göra i första hand är en heltäckande energikartläggning av sitt energisystem. 

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    Energieffektiviseringsåtgärder på Gustavsvik resorts AB
  • 110.
    Almulla, Youssef
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems.
    Energy-Water and Agriculture Nexus to Support the Sustainable Management of Shared Water Resources2023Doctoral thesis, comprehensive summary (Other academic)
    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.  

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  • 111.
    Almulla, Youssef
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems Analysis.
    Gulf Cooperation Council (GCC) countries 2040 energy scenario for electricity generation and water desalination.2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    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. 

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  • 112.
    Almulla, Youssef
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems.
    Zaimi, Klodian
    Polytechnic University of Tirana (UPT).
    Fejzic, Emir
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems.
    Sridharan, Vignesh
    Imperial College London.
    De Strasser, Lucia
    UNECE.
    Gardumi, Francesco
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy Systems.
    Hydropower and Climate Change, insights from the Integrated Water-Energy modelling of the Drin Basin.Manuscript (preprint) (Other academic)
    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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    summary
  • 113.
    Alonso Lozano, Alvaro
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Coal gasification in entrained flow gasifiers simulation & comparison2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
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    Coal gasification
  • 114.
    Al-Robaye, Ali
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Health Informatics and Logistics.
    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 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The entire world is confronting new challenges as a result of climate change. To mitigate human impact on the climate, the European Union and Sweden, as an EU member state, have decided to phase out the use of fossil fuels. The transition from fossil-fueled vehicles to electric ones has commenced, but Sweden is currently far from achieving a complete transition. The prerequisite for a complete transition is the establishment of a functional charging infrastructure capable of handling the increasing demand for charging. This report examines the current state of the Swedish charging infrastructure, highlights the factors hindering further development, and concludes by outlining the necessary steps for the Swedish charging infrastructure to facilitate transitions of 50-, 75-, and 100-percent from fossil-fueled to electric vehicles. Based on this analysis, it is evident that investments in public and home charging are critical factors at all levels of transition. Transparency and collaboration are currently lacking but are essential elements that must be in place for a successful and complete transition.

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    Ali_A_EX
  • 115.
    Al-Sallami, Omer
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences.
    CABLES DECOMMISSIONING IN OFFSHORE WIND FARMS: ENVIRONMENTAL AND ECONOMICAL PERSPECTIVE2021Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Addressing the decommissioning issues is vital to ensure a sustainable and effective process of such an essential part of the project life cycle. While there is a set of good practices and regulations that govern most of the decommissioning activities, the cable decommissioning issue is still in a big debate and often left abandoned at the seabed due to environmental concerns, as justified by most developers. This paper is aiming to understand the environmental and economic consequences of cable decommissioning.

    The available research papers and reports that are dealing with cable decommissioning issues have been reviewed. The cables are often decommissioned using similar methods to installation. However, there are no regulatory obligations to removing the cables in most countries. Cable installation will be associated with environmental impacts, but they are considered to be negligible. Additionally, Recycling cables’ copper is beneficial in both aspects environmentally and economically as copper prices are on the rise.

    A comparison between the ESs and decommissioning programs in a number of OWFSs have been conducted to understand the justification used for abandoning the cables. Most of the decommissioning reports have considered cable decommissioning to cause “considerable damage to seabed ecology”. However, that contradicts what was found in the ESs, where the impact level was considered negligible and anticipated to be similar to installation. It was unclear whether the abandonment of cables was driven by environmental considerations or not.

    A case study has been selected to compare cable and monopile decommissioning costs and the contribution of each component to the total decommissioning cost, including possible revenue generated from recycling. It was found that the cost-benefit of cable decommissioning is incomparable to monopile decommissioning as the latter is very costly, and the possible residual value is insignificant when compared to cables. Moreover, it is possible that the total cable decommissioning cost to be largely offset by the revenue generated from copper resell. Additionally, the cable decommissioning total cost can be almost paid by recycling cables if copper prices increase in the near future.

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    Offshore wind energy
  • 116.
    Al-samuraaiy, Omar
    Halmstad University, School of Business, Engineering and Science.
    Efficiency comparison between Heat Pump andMicro CHP located in two different location inSweden2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Efficiency of a ground source heat pump with thermal capacity of 6 kW determined in two differentlocations in Sweden. In the north side with low average temperature which could go down to -10 ᵒCand in the south side, with low average temperature with +2 ᵒC. The heat pump has refrigerantR407c, which could be connected to both, ground source heat feeding methods the horizontal, andthe vertical model. The heat pump give heat for both space heating and domestic hot watercompared the micro CHP which has thermal capacity of 12.5 kW and electrical capacity of 4.4 kW. Ithas IC engine which means the engine has internal combustion work. It also works with two kinds offuel, natural gas and propane MOZ 92; the energy and exergy of the fuel in micro CHP feeding thethermal process by heat. That heat used for space heating and domestic hot water after going outthe process for the cooling which keep the heat in storage tank and it heat the liquid to the gas to beused in the turbine to produce the electricity. The two locations in the north and south of Swedenwill influence the thermal operation and that influence power used for compressor for heat pumpand somehow the pump in the micro CHP. The study shows that the different in exergy and energyefficiency between these two heat technologies by located them in the locations. Higher efficiencyof the micro CHP which give the advantage of use Micro CHP some technology give the benefit byusing the fuel for producing the heating and electricity , the benefit which give the customer manybenefit shows in the study. That’s comparing with the heat pump which is large use in Sweden. Inthis paper will introduce Micro CHP as heating technology which has been used in the rest of Europecould be used in Sweden for future heating technology with electricity producing, shall change thecostumer from energy consumption costumer to producing costumer.

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  • 117. AlSkaif, T.
    et al.
    Zapata, M. G.
    Bellalta, B.
    Nilsson, Anders
    KTH, School of Architecture and the Built Environment (ABE), Sustainable development, Environmental science and Engineering.
    A distributed power sharing framework among households in microgrids: a repeated game approach2016In: Computing, ISSN 0010-485X, E-ISSN 1436-5057, Vol. 99, no 1, p. 23-37Article in journal (Refereed)
    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 %.

  • 118.
    Alsterlund, Hanna
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Industrial Engineering & Management.
    Effektiva återkopplingsverktyg för elanvändning: En studie som syftar till att identifiera utvecklingsmöjligheter för att uppnå ett mer hållbart energisystem år 20302015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Feedback tools support electricity users within the Swedish residential sector to increase their knowledge of electricity and the electricity market as well as to become more aware of their electricity consumption, which in turn encourages a reduction and an increased flexibility of electricity use. The primary aim of this study is to identify and analyse how existing feedback tools can be improved, to ensure that they contribute efficiently to the achievement of the EU objectives congruent with a more sustainable energy system in 2030, emphasizing: greenhouse gas reduction, increased energy efficiency and an increased share of renewable energy. In order to reach the primary aim of this study, existing feedback tools have been identified and mapped and interviews with feedback tools providers have been conducted. The study is limited to three research areas: the practical functions of feedback tools, available technology and the use of feedback tools.

    The use of more efficient feedback tools will provide an increased success rate for energy management, which includes both behavioural changes and energy efficiency. According to the results from the interviews conducted for this study, an increased use and user frequency is important to utilise the energy management potential. Efficient feedback tools can be achieved by developing existing tool functions. The desired development aims to reduce the effort required of the user, promote immediate and continuous feedback and to increase usability. However, the study shows that in order to achieve maximum effect, adaptions to specific needs of the users have to be made. An increased efficiency may also be achieved with additional features to allow more flexible consumption and encourage further energy efficiency measures.

    The technical aspect is important in order to implement more efficient feedback tools. Existing techniques for data collection should be developed in order to reduce the effort required of the user, enhance the quality and resolution of the data and finally prevent technology limitations, hence enabling feedback tools to be used by all users.

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  • 119.
    Alvehag, Karin
    et al.
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Söder, Lennart
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    Quality regulation impact on investment decisions in distribution system reliability2012In: 9th International Conference on the European Energy Market, EEM 12, IEEE , 2012, p. 6254646-Conference paper (Refereed)
    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.

  • 120.
    Alvfors, Per
    et al.
    Energiprocesser, Kungliga Tekniska Högskolan, KTH, Stockholm.
    Ellegård, Kajsa
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Harvey, Simon
    Energiteknik/Rymd-, geo- och miljövetenskap, Chalmers Tekniska högskola, Göteborg.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Palm, Jenny
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Widén, Joakim
    Linköpings universitet.
    Forskarskolan Program Energisystem: Kunskapsutveckling genom samverkan mellan teknik- och samhällsvetenskap : slutrapport 2016, Forskningssyntes för konsortiet Byggnader i energisystem2016Report (Other academic)
    Abstract [sv]

    Denna rapport ger en kortfattad översikt och syntes av tvärvetenskapliga forskningsresultat från verksamheten i konsortiet Byggnader i energisystem inom forskarskolan Program Energisystem. Tonvikten ligger på tiden från forskarskolans start 1997 till dess 15-årsjubileum 2012, men hänvisningar görs även till forskning publicerad därefter. Utgångspunkten har varit att lyfta fram det tvärvetenskapliga inom forskningen för att visa hur forskarskolan har bidragit till tvärvetenskaplig kunskaps- och metodutveckling.

    I rapporten ges en översikt över fallstudier och avhandlingar inom konsortiet och de tvärvetenskapliga forskningsresultaten sammanfattas inom tre huvudsakliga tematiska områden: (1) Passivhus: boende och energieffektiva byggnadstekniker,

    (2) Energieffektivisering: processer och aktörer, samt (3) Energianvändning, vardagsaktiviteter och småskalig solenergi i hushåll. Tvärvetenskapliga metoder och resultat sammanfattas och utvecklingen av samarbeten och angreppssätt beskrivs. Rapporten avslutas med några sammanfattande reflektioner kring hur framgångsrik tvärvetenskaplig forskning bör bedrivas.

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    Forskarskolan Program Energisystem: Kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap: Slutrapport 2016, Forskningssyntes för konsortiet Byggnader i energisystem
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  • 121.
    Alvfors, Per
    et al.
    Energiprocesser, Kungliga Tekniska Högskolan, KTH, Stockholm.
    Ellegård, Kajsa
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Harvey, Simon
    Energiteknik/Rymd-, geo- och miljövetenskap, Chalmers Tekniska högskola, Göteborg.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Palm, Jenny
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Widén, Joakim
    Linköpings universitet.
    Forskarskolan Program Energisystem: kunskapsutveckling genom samverkan mellan teknik- och samhällsvetenskap : slutrapport 2016, Publikationer från Program Energisystem2016Report (Other academic)
    Abstract [sv]

    Det finns en omfattande publicering från Program Energisystem. Förutom 78 doktorsavhandlingar och 16 licentiatavhandlingar så har forskarstuderande och seniorer publicerat ytterligare minst 500 publikationer inom ramen för Program Energisystem.

    I denna rapport förtecknas dessa publikationer.

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    Forskarskolan Program Energisystem: Kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap: Slutrapport 2016, Publikationer från Program Energisystem
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  • 122.
    Alvfors, Per
    et al.
    Energiprocesser, Kungliga Tekniska Högskolan, KTH, Stockholm.
    Ellegård, Kajsa
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Harvey, Simon
    Energiteknik/Rymd-, geo- och miljövetenskap, Chalmers Tekniska högskola, Göteborg.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Palm, Jenny
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Widén, Joakim
    Linköpings universitet.
    Forskarskolan Program Energisystem: kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap : slutrapport 2016, Forskningssyntes för konsortiet Lokala och regionala energisystem2016Report (Other academic)
    Abstract [sv]

    Forskarskolan Program Energisystem har med sina fem deltagande forskningsavdelningar från Chalmers tekniska högskola, Linköpings universitet, KTH och Uppsala universitet varit banbrytande inom tvärvetenskaplig energisystemforskning och dess tre konsortier har spelat en viktig roll för forskarskolans utveckling. Konsortierna är inriktade på byggnader i energisystem, industriella energisystem samt lokala och regionala energisystem. I varje konsortium har doktorander och seniorer från minst två av de deltagande avdelningarna bedrivit tvärvetenskaplig forskning.

    I det lokala och regionala konsortiet har forskningsfrågorna kretsat kring aktörer och processer av betydelse för energisystemen i svenska kommuner, län och regioner. Inom konsortiet har frågeställningar om miljömässigt, socialt och ekonomiskt hållbara lokala och regionala energisystem bland annat studerats genom att analysera aktörers agerande och politiska processer inom de tekniska, ekonomiska och institutionella villkor som utgör begränsningar och möjligheter för energisystemen. En tydlig trend inom konsortiets forskning under forskarskolans arton år är att inriktningen gått i riktning från lokal till regional och från stationära till mobila energisystem. Den förskjutningen följer också den ökande betydelse som regioner i form av länsstyrelser har fått för samordningen av energi- och klimatplaneringen i Sverige under det senaste decenniet. Kommunerna har fortfarande en dominerande position genom den energirelaterade infrastruktur som de förfogar över men en förskjutning mot ett mer regionalt inflytande är tydlig.

    Totalt har 26 doktors- och en licentiatexamen avlagts av konsortiets doktorander och dessa alumner är nu verksamma inom energirelaterade verksamheter Sverige. Den främsta representationen finns inom myndigheter och akademier.

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    Forskarskolan Program Energisystem: Kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap: Slutrapport 2016, Forskningssyntes för konsortiet Lokala och regionala energisystem
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  • 123.
    Alvfors, Per
    et al.
    Energiprocesser, Kungliga Tekniska Högskolan, KTH, Stockholm.
    Ellegård, Kajsa
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Harvey, Simon
    Energiteknik/Rymd-, geo- och miljövetenskap, Chalmers Tekniska högskola, Göteborg.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Palm, Jenny
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Widén, Joakim
    Institutionen för teknikvetenskaper, Byggteknik, Uppsala universitet.
    Forskarskolan Program Energisystem: kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap : slutrapport 2016, Huvudrapport2016Report (Other academic)
    Abstract [sv]

    Idén att samhällsvetenskaplig och teknisk energisystemforskning måste vävas samman för att utveckla ny kunskap och få ökad samhällsnytta var utgångspunkt när Program Energisystem startade år 1997.

    Program Energisystem identifierade tidigt kärnvärden som visades vara viktiga framgångsfaktorer:

    • Energisystem med tyngdpunkt på användarsidan
    • Tvärvetenskaplig, universitets- och fakultetsöverskridande
    • forskning och forskarutbildning
    • Sammanhållen forskarskola
    • Finansiering av hela doktorandprojekt
    • Samarbeten i tematiska forskningsområden
    • Kontinuerlig tvärvetenskaplig utveckling
    • Långsiktig finansiering av samordningsstruktur

    Program Energisystems arbete har kännetecknats av:

    • Val av samhällsrelevanta projekt av hög vetenskaplig kvalitet
    • Gemensamma tvärvetenskapliga kurser och projektarbeten
    • Tvärvetenskaplig handledning
    • Kontinuerligt arbetande fora för diskussion
    • och kontakter över ämnesgränser
    • Forskningssamarbeten mellan seniorer i olika ämnen
    • Aktivt doktorand- och alumninätverk

    Forskarutbildningens målsättning har varit att utbilda bättre samhällsvetare

    och bättre ingenjörer, inte att göra samhällsvetare av ingenjörerna eller ingenjörer

    av samhällsvetarna.

    I den kontinuerliga utvecklingen av Program Energisystem har ett förtroendefullt samarbete utvecklats som möjliggjort kontinuerliga förbättringar av forskningen och forskarutbildningen.

    Arvet från Program Energisystem har förts vidare i den nya Forskarskola Energisystem. Forskarskola Energisystem har en delvis annan struktur men bygger innehållsmässigt vidare på centrala idéer från Program Energisystem. Det finns ett fortsatt stort behov av tvärvetenskaplig kunskapsutveckling på energiområdet som främst handlar om att förstå komplicerade samband och processer och hur dessa kan påverkas.

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    Forskarskolan Program Energisystem: Kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap: Slutrapport 2016, Huvudrapport
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  • 124.
    Alvfors, Per
    et al.
    Energiprocesser, Kungliga Tekniska Högskolan, KTH, Stockholm.
    Ellegård, Kajsa
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Harvey, Simon
    Energiteknik/Rymd-, geo- och miljövetenskap, Chalmers Tekniska högskola, Göteborg.
    Karlsson, Magnus
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Palm, Jenny
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Söderström, Mats
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering.
    Widén, Joakim
    Institutionen för teknikvetenskaper, Byggteknik, Uppsala universitet.
    Forskarskolan Program Energisystem: Kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap: Slutrapport 2016, Forskningssyntes för konsortiet Industriella energisystem2016Report (Other academic)
    Abstract [sv]

    Denna syntesrapport är en sammanfattning och analys av den forskning som bedrivits inom ramen för det Industriella konsortiet från år 1997 (konsortiets verksamhet startade 1999) inom ramen för forskarskolan Program Energisystem. Under denna tid har 25 doktorsavhandlingar och en licentiatavhandling producerats inom det Industriella konsortiet. Avhandlingarna sammanfattas och analyseras i denna syntesrapport och arbetet avgränsas då till att studera avhandlingarnas Problemområde, Verktyg/Metod/Teori, Systemgräns, studerad Sektor och Övergripande resultat. Vidare ges, med utgångspunkt från dessa forskningsresultat, förslag på fortsatt forskning för hållbara och effektiva energisystem.

    Många viktiga problemområden har studerats inom ramen för forskarskolans Industrikonsortium. Ett flertal avhandlingar behandlar möjligheter att minska utsläppen av växthusgaser från industrin och här har flera sektorer studerats, bland annat massa- och pappersindustrin, järn- och stålindustrin, kemiindustrin och oljeraffinaderiindustrin. Ett centralt tema i avhandlingarna är potentialer för energieffektivisering i industrisektorn, inte minst vid införande av bioraffinaderikoncept i framtiden. Här analyseras t.ex. tekniska potentialer, kostnadseffektivitet för energieffektiviseringsåtgärder, samt betydelsen av energiledning och styrmedel.

    I avhandlingarna har en mängd olika metoder och verktyg använts. Den i särklass mest använda vetenskapliga metoden är intervjuer (15) följt av scenarioanalys (10), dokumentstudier (9), simuleringsberäkningar (9), pinchanalys (9) och optimering (8). Fallstudiemetodik där mer än en metod används för att studera ett specifikt fall, t.ex. ett företag, förekommer i flera avhandlingar. En grundtanke i forskarskolan Program Energisystem har varit att forskaren måste vara medveten om att resultat från energisystemanalyser kan påverkas av vilka systemgränser som valts. I flertalet av Industrikonsortiets avhandlingar har Europas elsystem utgjort systemgräns då effekter av förändrad elanvändning eller elproduktion analyserats.

    Industrikonsortiets forskningsresultat visar på många intressanta slutsatser. Det påvisas att det finns energieffektiviseringspotentialer både i nya investeringar och i energiledningsåtgärder, som att justera driftsbetingelser för befintlig teknisk utrustning och ändra beteenden. Det konstateras också att energisamarbeten mellan industri och energibolag med syfte att öka användningen av industriell överskottsvärme i många fall är en hållbar lösning som minskar regioners behov av primärenergi och reducerar utsläppen av växthusgaser. Hinder mot sådana samarbeten kan vara att detta inte är en del av industrins kärnverksamhet. Det konstateras även att energisamarbeten mellan närliggande anläggningar i ett industrikluster kan leda till avsevärt större energieffektiviseringspotentialer än om var och en av de ingående industrierna arbetar enbart med interna åtgärder. Hinder mot denna typ av samarbete är brist på etablerade affärsmodeller. Forskningen visar på ett behov av fortsatta studier kring begreppet kärnverksamhet och dess påverkan på energifrågan i svensk industrin. Avskiljning och lagring av koldioxid (CCS) från industrin har studerats och här konstateras att denna lösning inte är ekonomiskt lönsam med dagens förutsättningar. Det rekommenderas därför att framtida forskning bedrivs för att studera vilka styrmedel som skulle behövas för att CCS ska bli ekonomiskt intressant för industrin. En annan viktig fråga är hur energitjänsteföretag ska formulera affärsmodeller och strategier kring CCS, samt hur de kan samarbeta med industrin för att på affärsmässiga grunder få till stånd CO2– avskiljning, transport och lagring. Även framtida forskning kring styrmedel, t.ex. energitjänster, för ökad energieffektivitet i industrisektorn förordas. Resultat från Industrikonsortiets avhandlingar visar att processintegrationsverktyget pinchanalys kan kombineras med optimeringsverktyg (i detta fall MIND) vid analys av industriella energisystem. Denna metodkombination ger intressanta resultat varför fortsatt forskning förordas kring kombinationer av olika processintegrationsmetoder. I flertalet avhandlingar har företagsdata använts som indata vid exempelvis modellering och processintegrationsstudier. Detta har accentuerat behovet av ett standardiserat protokoll vid insamling av företagsdata. Ett sådant protokoll kan öka reliabiliteten på indata och förslagsvis användas vid fallstudier.

    Avslutningsvis kan konstateras att trots närmare 20 års tvärvetenskaplig forskning mellan samhällsvetare och teknikvetenskaperna finns det fortfarande mycket mer att beforska och utveckla.

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    Forskarskolan Program Energisystem: Kunskapsutveckling genom samverkanmellan teknik- och samhällsvetenskap: Slutrapport 2016, Forskningssyntes för konsortiet Industriella energisystem
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  • 125.
    Alvi, Naveed
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Soto Rodriguez, Paul E. D.
    Univ Complutense Madrid, Spain.
    ul Hassan, Waheed
    Bahauddin Zakariya Univ, Pakistan.
    Zhou, Guofu
    South China Normal Univ, Peoples R China.
    Willander, Magnus
    Linköping University, Department of Science and Technology, Physics, Electronics and Mathematics. Linköping University, Faculty of Science & Engineering.
    Notzel, Richard
    South China Normal Univ, Peoples R China.
    Unassisted water splitting with 9.3% efficiency by a single quantum nanostructure photoelectrode2019In: International journal of hydrogen energy, ISSN 0360-3199, E-ISSN 1879-3487, Vol. 44, no 36, p. 19650-19657Article in journal (Refereed)
    Abstract [en]

    To split water and produce hydrogen by white light is an excellent solution for the storage and supply of clean and sustainable energy. Efficiency and stability are the key challenges for a successful exploitation. InGaN, evaluated against other semiconductors, metal oxides, carbon based - and organic materials has most suited intrinsic materials properties. Based on this optimum materials choice we report photoelectrochemical (PEC) hydrogen generation under white light illumination by an InGaN-based quantum nanostructure photoelectrode. No degradation occurs for operation over 10 h. Our novel concept, combining quantum nanostructure physics with electrochemistry and catalysis leads to almost 10% efficiency at zero external voltage. The efficiency rises above 25% at 0.2 V. This is unmatched for a single photoelectrode, representing the most advanced technology of low complexity. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

  • 126.
    Alvors, Per
    et al.
    Kungl. Tekniska Högskolan, KTH, Stockholm.
    Arnell, Jenny
    Svenska Miljöinstitutet.
    Berglin, Niklas
    Innventia AB, Stockholm, Sweden.
    Björnsson, Lovisa
    Miljö- och energisystem, Lunds Tekniska Högskola, Lund.
    Börjesson, Pål
    Miljö- och energisystem, Lunds Tekniska Högskola, Lund.
    Grahn, Maria
    Department of Energy and Environment, Chalmers University of Technology, Sweden.
    Harvey, Simon
    Chalmers University of Technology, Dept. of Energy and Environment, Heat and Power Technology Division,Göteborg, Sweden.
    Hoffstedt, Christian
    Innventia AB, Stockholm, Sweden.
    Holmgren, Kristina
    Svenska Miljöinstitutet.
    Jelse, Kristian
    Svenska Miljöinstitutet.
    Klintbom, Patrik
    Volvo AB, Sweden.
    Kusar, Henrik
    Kemisk Teknologi, Kungliga Tekniska Högskolan, KTH, Stockholm.
    Lidén, Gunnar
    Department of Chemical Engineering, Lund University, Sweden.
    Magnusson, Mimmi
    Skolan för kemivetenskap, Kungliga Tekniska Högskolan, Stockholm.
    Pettersson, Karin
    Energi och miljö/Energiteknik, Chalmers Tekniska Högskola, Göteborg.
    Rydberg, Tomas
    Svenska Miljöinstitutet.
    Sjöström, Krister
    School of Chemical Science and Engineering, Kungliga Tekniska Högskolan, Stockholm.
    Stålbrand, Henrik
    Biokemi och Strukturbiologi, Lunds universitet, Lund.
    Wallberg, Ola
    Institutionen för kemiteknik, Lunds universitet, Lund.
    Wetterlund, Elisabeth
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, The Institute of Technology.
    Zacchi, Guido
    Institutionen för kemiteknik, Lunds universitet, Lund.
    Öhrman, Olof
    Institutionen för samhällsbyggnad och naturresurser, Luleå Tekniska universitet.
    Research and development challenges for Swedish biofuel actors – three illustrative examples: Improvement potential discussed in the context of Well-to-Tank analyses2010Report (Other academic)
    Abstract [en]

    Currently biofuels have strong political support, both in the EU and Sweden. The EU has, for example, set a target for the use of renewable fuels in the transportation sector stating that all EU member states should use 10% renewable fuels for transport by 2020. Fulfilling this ambition will lead to an enormous market for biofuels during the coming decade. To avoid increasing production of biofuels based on agriculture crops that require considerable use of arable area, focus is now to move towards more advanced second generation (2G) biofuels that can be produced from biomass feedstocks associated with a more efficient land use.

    Climate benefits and greenhouse gas (GHG) balances are aspects often discussed in conjunction with sustainability and biofuels. The total GHG emissions associated with production and usage of biofuels depend on the entire fuel production chain, mainly the agriculture or forestry feedstock systems and the manufacturing process. To compare different biofuel production pathways it is essential to conduct an environmental assessment using the well-to-tank (WTT) analysis methodology.

    In Sweden the conditions for biomass production are favourable and we have promising second generation biofuels technologies that are currently in the demonstration phase. In this study we have chosen to focus on cellulose based ethanol, methane from gasification of solid wood as well as DME from gasification of black liquor, with the purpose of identifying research and development potentials that may result in improvements in the WTT emission values. The main objective of this study is thus to identify research and development challenges for Swedish biofuel actors based on literature studies as well as discussions with the the researchers themselves. We have also discussed improvement potentials for the agriculture and forestry part of the WTT chain. The aim of this study is to, in the context of WTT analyses, (i) increase knowledge about the complexity of biofuel production, (ii) identify and discuss improvement potentials, regarding energy efficiency and GHG emissions, for three biofuel production cases, as well as (iii) identify and discuss improvement potentials regarding biomass supply, including agriculture/forestry. The scope of the study is limited to discussing the technologies, system aspects and climate impacts associated with the production stage. Aspects such as the influence on biodiversity and other environmental and social parameters fall beyond the scope of this study.

    We find that improvement potentials for emissions reductions within the agriculture/forestry part of the WTT chain include changing the use of diesel to low-CO2-emitting fuels, changing to more fuel-efficient tractors, more efficient cultivation and manufacture of fertilizers (commercial nitrogen fertilizer can be produced in plants which have nitrous oxide gas cleaning) as well as improved fertilization strategies (more precise nitrogen application during the cropping season). Furthermore, the cultivation of annual feedstock crops could be avoided on land rich in carbon, such as peat soils and new agriculture systems could be introduced that lower the demand for ploughing and harrowing. Other options for improving the WTT emission values includes introducing new types of crops, such as wheat with higher content of starch or willow with a higher content of cellulose.

    From the case study on lignocellulosic ethanol we find that 2G ethanol, with co-production of biogas, electricity, heat and/or wood pellet, has a promising role to play in the development of sustainable biofuel production systems. Depending on available raw materials, heat sinks, demand for biogas as vehicle fuel and existing 1G ethanol plants suitable for integration, 2G ethanol production systems may be designed differently to optimize the economic conditions and maximize profitability. However, the complexity connected to the development of the most optimal production systems require improved knowledge and involvement of several actors from different competence areas, such as chemical and biochemical engineering, process design and integration and energy and environmental systems analysis, which may be a potential barrier.

    Three important results from the lignocellulosic ethanol study are: (i) the production systems could be far more complex and intelligently designed than previous studies show, (ii) the potential improvements consist of a large number of combinations of process integration options wich partly depends on specific local conditions, (iii) the environmental performance of individual systems may vary significantly due to systems design and local conditons.

    From the case study on gasification of solid biomass for the production of biomethane we find that one of the main advantages of this technology is its high efficiency in respect to converting biomass into fuels for transport. For future research we see a need for improvements within the gas up-grading section, including gas cleaning and gas conditioning, to obtain a more efficient process. A major challenge is to remove the tar before the methanation reaction.

    Three important results from the biomethane study are: (i) it is important not to crack the methane already produced in the syngas, which indicates a need for improved catalysts for selective tar cracking, (ii) there is a need for new gas separation techniques to facilitate the use of air oxidation agent instead of oxygen in the gasifier, and (iii) there is a need for testing the integrated process under realistic conditions, both at atmospheric and pressurized conditions.

    From the case study on black liquor gasification for the production of DME we find that the process has many advantages compared to other biofuel production options, such as the fact that black liquor is already partially processed and exists in a pumpable, liquid form, and that the process is pressurised and tightly integrated with the pulp mill, which enhances fuel production efficiency. However, to achieve commercial status, some challenges still remain, such as demonstrating that materials and plant equipment meet the high availability required when scaling up to industrial size in the pulp mill, and also proving that the plant can operate according to calculated heat and material balances. Three important results from the DME study are: (i) that modern chemical pulp mills, having a potential surplus of energy, could become important suppliers of renewable fuels for transport, (ii) there is a need to demonstrate that renewable DME/methanol will be proven to function in large scale, and (iii) there is still potential for technology improvements and enhanced energy integration.

    Although quantitative improvement potentials are given in the three biofuel production cases, it is not obvious how these potentials would affect WTT values, since the biofuel production processes are complex and changing one parameter impacts other parameters. The improvement potentials are therefore discussed qualitatively. From the entire study we have come to agree on the following common conclusions: (i) research and development in Sweden within the three studied 2G biofuel production technologies is extensive, (ii) in general, the processes, within the three cases, work well at pilot and demonstration scale and are now in a phase to be proven in large scale, (iii) there is still room for improvement although some processes have been known for decades, (iv) the biofuel production processes are complex and site specific and process improvements need to be seen and judged from a broad systems perspective (both within the production plant as well as in the entire well-to-tank perspective), and (v) the three studied biofuel production systems are complementary technologies. Futher, the process of conducting this study is worth mentioning as a result itself, i.e. that many different actors within the field have proven their ability and willingness to contribute to a common report, and that the cooperation climate was very positive and bodes well for possible future collaboration within the framework of the f3 center.

    Finally, judging from the political ambitions it is clear that the demand for renewable fuels will significantly increase during the coming decade. This will most likely result in opportunities for a range of biofuel options. The studied biofuel options all represent 2G biofuels and they can all be part of the solution to meet the increased renewable fuel demand.

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    Research and development challenges for Swedish biofuel actors – three illustrative examples: Improvement potential discussed in the context of Well-to-Tank analyses
  • 127.
    Amars, Latif
    et al.
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Centre for Climate Science and Policy Research, CSPR. Independent Climate Researcher, Dar es Salaam, Tanzania.
    Fridahl, Mathias
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Centre for Climate Science and Policy Research, CSPR.
    Hagemann, Markus
    NewClimate Institute, Germany.
    Röser, Frauke
    NewClimate Institute, Germany.
    Linnér, Björn-Ola
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Department of Thematic Studies, Centre for Climate Science and Policy Research.
    The transformational potential of Nationally Appropriate Mitigation Actions in Tanzania: assessing the concept’s cultural legitimacy among stakeholders in the solar energy sector2017In: Local Environment: the International Journal of Justice and Sustainability, ISSN 1354-9839, E-ISSN 1469-6711, Vol. 22, no 1, p. 86-105Article in journal (Refereed)
    Abstract [en]

    While energy-sector emissions remain the biggest source of climate change, many least-developed countries still invest in fossil-fuel development paths. These countries generally have high levels of fossil fuel technology lock-in and low capacities to change, making the shift to sustainable energy difficult. Tanzania, a telling example, is projected to triple fossil-fuel power production in the next decade. This article assesses the potential to use internationally supported Nationally Appropriate Mitigation Actions (NAMAs) to develop solar energy in Tanzania and contribute to transformational change of the electricity supply system. By assessing the cultural legitimacy of NAMAs among key stakeholders in the solar energy sector, we analyse the conditions for successful uptake of the concept in (1) national political thought and institutional frameworks and (2) the solar energy niche. Interview data are analysed from a multi-level perspective on transition, focusing on its cultural dimension. Several framings undermining legitimacy are articulated, such as attaching low-actor credibility to responsible agencies and the concept’s poor fit with political priorities. Actors that discern opportunities for NAMAs could, however, draw on a framing of high commensurability between experienced social needs and opportunities to use NAMAs to address them through climate compatible development. This legitimises NAMAs and could challenge opposing framings.

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  • 128.
    Ameen, Arman
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering.
    Energianalys och energieffektivisering av en förskola: Söderskolan (Slottets förskola) i Gävle, simulering utförd genom IDA ICE 4.612014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Bostad- och servicesektorn står för 38 % av Sveriges totala energianvändning. Av det här står bostäder och lokaler för 90 % av energianvändningen och nästan 60 % av det går till att värma upp byggnaderna och till varmvatten. Därför är det viktig att börja titta på den här sektorn och se om det finns möjlighet att spara på energianvändningen. I den här studien har en kartläggning gjorts av en gammal skolbyggnad för att kunna skapa ett underlag för energieffektiviseringsåtgärder. Genom att använda simuleringsprogrammet IDA ICE 4.61 har man skapat en basmodell av byggnaden som då används som simuleringsbas. Basmodellen har jämförts med fjärrvärmekostnader för att kunna verifieras. Därefter har man lagt in energieffektiviserar och tittat på vilka besparingar man har kommit fram till. Resultatet av den här studien visade att i den här byggnaden så är den mest effektiva åtgärden isolering av taket till vinden.

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  • 129.
    Ameen, Arman
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Experimental and numerical study of corner impinging jet ventilation for an office environment2024Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    An effective ventilation system is an important component of a building’s service infrastructure. It serves the dual purpose of creating a comfortable and healthy indoor environment for occupants, thereby enhancing their well-being and productivity. However, the ventilation system is also a part of the building that uses a high amount of energy.

    The main objective of this study is to evaluate a novel implementation of the impinging jet ventilation system by placing the supply inlet at the corners of the space or room, rather than in the traditional mid-wall section. The focus of this study is to test and evaluate corner impinging jet ventilation in a medium-sized office environment within a building that requires moderate amount of heating and cooling.

    In the first part of this study (summer condition), the system is evaluated in an experimental environment, where it is compared against other systems such as displacement ventilation and mixing ventilation. The evaluated parameters indicates that corner impinging ventilation system performs better than mixing ventilation but show similar results to displacement ventilation in terms of airchange effectiveness. This experimental setup was also tested in winter condition and the results showed that the system was most effective during summertime compared to wintertime. In wintertime the results for the air change effectiveness were similar to those of a mixing system.

    In the second part, numerical simulations were utilized to delve deeper into the behaviour of the corner impinging jet ventilation system close to the floor surface. A numerical model was created and validated against experimental measurements. In this part, the spreading of the air jet across the room floor was examined, and its relation to various parameters such as inlet velocity, inlet shape and discharge height. Results indicated that diffuser geometries have almost no impact on velocity profile along the floor's centreline, jet spreading rate and maximum velocity decay. The results also showed a high degree of flexibility for the room size, between 25-100 m2 for which the results were applicable. The results also concluded that there was a noticeable confinement effect present and that the jet was able to travel far into the room.

    In the third part numerical simulations was used for validating and to create a model for an office room containing two office workstations. The office room was evaluated in terms of local thermal comfort, close to the sitting area. In addition, the indoor air quality was also examined. The results showed that corner impinging ventilation system performed better than conventional mixing ventilation system, especially when evaluating the indoor air quality in terms of mean age of air. This evaluation also took into account both outdoor summer and winter conditions, as well as different inlet surface areas. Different locations for the workstations were also evaluated with good results, except for placing the work-stations close to the inlets. Due to the system’s effectiveness of providing fresh air to the occupants, further analysis was made to try and reduce the air flowrate but keep the same indoor air quality level as an equivalent fully mixing ventilation system. By using this method, the study was able to demonstrate reduction in the energy use by reducing the air flowrate of the supply inlet. The study showed a possible reduction of the energy use by 7-9 % for outdoor temperatures ranging between -15 °C to 25 °C.

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  • 130.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Bahrami, Alireza
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Elousa Ansa, Ibai
    Assessment of Thermal Comfort and Indoor Air Quality in Library Group Study Rooms2023In: Buildings, E-ISSN 2075-5309, Vol. 13, no 5, article id 1145Article in journal (Refereed)
    Abstract [en]

    Human performance and health are among the most relevant topics in the modern society, especially at young ages, when academic performance is indispensable. Thus, as humans spend most of their lifetime inside a building, thermal comfort and indoor air quality are an essential aspect of a room. The aim of the current study is to numerically evaluate the main thermal comfort parameters such as PMV and PPD as well as indoor air quality, i.e., CO2 concentration, in library group study rooms at the University of Gävle in Sweden. Rotroninc Measurement Solutions CL11 sensors were utilized for temperature measurements. Simulation models were created and validated based of building data as well as temperature measurements. Several simulations were conducted throughout a year, covering different periods. The results show that even though the ventilation system, with only temperature control, works as intended for maintaining the thermal comfort, the CO2 concentration rises above 1000 ppm when more than one student occupy the rooms, which is not recommended by different thermal comfort ruling institutions. Consequently, a modification to the ventilation system control is recommended, changing it from temperature control to CO2 and temperature control.

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  • 131.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Numerical investigation of indoor thermal comfort and air quality for an office equipped with corner impinging jet ventilation2023In: Advances in Building Energy Research, ISSN 1751-2549, E-ISSN 1756-2201, Vol. 17, no 5, p. 578-604Article in journal (Refereed)
    Abstract [en]

    This study investigates the feasibility of using only corner impinging jet ventilation (CIJV) for heating and cooling a medium-sized office space with two occupants while maintaining adequate indoor thermal comfort and air quality compared to traditional mixing ventilation systems. This study examines what impact various outdoor temperatures, ranging from −15°C to 25°C, have on an office environment in terms of indoor thermal comfort and air quality. Three different workspace positions were evaluated. The results show that the CIJV system meets the ASHRAE thermal comfort standards for all three positions. In terms of indoor air quality, CIJV performs better than traditional mixing systems, with improved mean age of air and ACE values. This study concludes that CIJV can be used both close and far away from the supply inlets and still provide adequate indoor thermal comfort and air quality during both cooling and heating season.

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  • 132.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Larsson, Ulf
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Experimental Investigation of Ventilation Performance of Different Air Distribution Systems in an Office Environment: Heating Mode2019In: Energies, E-ISSN 1996-1073, Vol. 12, no 10, article id 1835Article in journal (Refereed)
    Abstract [en]

    A vital requirement for all-air ventilation systems are their functionality to operate both in cooling and heating mode. This article experimentally investigates two newly designed air distribution systems, corner impinging jet (CIJV) and hybrid displacement ventilation (HDV) in comparison against a mixing type air distribution system. These three different systems are examined and compared to one another to evaluate their performance based on local thermal comfort and ventilation effectiveness when operating in heating mode. The evaluated test room is an office environment with two workstations. One of the office walls, which has three windows, faces a cold climate chamber. The results show that CIJV and HDV perform similar to a mixing ventilation in terms of ventilation effectiveness close to the workstations. As for local thermal comfort evaluation, the results show a small advantage for CIJV in the occupied zone. Comparing C2-CIJV to C2-CMV the average draught rate (DR) in the occupied zone is 0.3% for C2-CIJV and 5.3% for C2-CMV with the highest difference reaching as high as 10% at the height of 1.7 m. The results indicate that these systems can perform as well as mixing ventilation when used in offices that require moderate heating. The results also show that downdraught from the windows greatly impacts on the overall airflow and temperature pattern in the room.

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  • 133.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Yamasawa, Haruna
    Osaka University, Japan..
    Kobayashi, Tomohiro
    Osaka University, Japan..
    Karimipanah, Taghi
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Energy saving, indoor thermal comfort and indoor air quality evaluation of an office environment using corner impinging jet ventilation2023In: Developments in the Built Environment, ISSN 2666-1659, Vol. 15, article id 100179Article in journal (Refereed)
    Abstract [en]

    The performance of a corner based impinging jet ventilation system (CIJV) in an office environment was evaluated numerically. The evaluation was done both in terms of the local thermal comfort and the local indoor air quality. Three different inlet configurations were tested for a range of outdoor temperatures that included both winter and summer conditions. In terms of indoor air quality, the results showed that CIJV performed better than a traditional mixing system. The study also revealed that CIJV creates a stronger temperature stratification in summertime compared to wintertime. When evaluating the energy saving potential the results showed a possible reduction of 7% for the ventilation flowrate when the outdoor temperatures were between -15 °C and -5 °C, 8 % when the outdoor temperatures were between 0 °C and 10 °C and 9 % when the outdoor temperatures were between 15 °C and 25 °C.

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  • 134.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Choonya, Gasper
    Cehlin, Mathias
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Experimental Evaluation of the Ventilation Effectiveness of Corner Stratum Ventilation in an Office Environment2019In: Buildings, E-ISSN 2075-5309, Vol. 9, no 7, article id 169Article in journal (Refereed)
    Abstract [en]

    An experimental study was conducted in a room resembling an office in a laboratory environment. The study involved investigating the ability of corner-placed stratum ventilation in order to evaluate the ventilation’s effectiveness and local thermal comfort. At fixed positions, the air temperature, air velocity, turbulence intensity, and tracer gas decay measurements were carried out. The results show that corner-placed stratum ventilation behaves very similar to a mixing ventilation system when considering air change effectiveness. The performance of the system was better at lower supply air flow rates for heat removal effectiveness. For the heating cases, the draught rates were all very low, with the maximum measured value of 12%. However, for the cooling cases, the maximum draught rate was 20% and occurred at ankle level in the middle of the room.

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  • 135.
    Ameen, Arman
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Mattsson, Magnus
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building Engineering, Energy Systems and Sustainability Science, Energy Systems and Building Technology.
    Boström, Hanna
    Lindelöw, Hanna
    Assessment of Thermal Comfort and Air Quality in Office Rooms of a Historic Building: A Case Study in Springtime in Continental Climate2023In: Buildings, E-ISSN 2075-5309, Vol. 13, no 1, article id 156Article in journal (Refereed)
    Abstract [en]

    One of the most important aspects of working in an office environment is ensuring that the space has optimal thermal comfort and an indoor environment. The aim of this research is to investigate the thermal comfort and indoor climate in three office rooms located at one of the campus buildings at the University of Gävle, Sweden. The evaluated period is in the month of April during springtime. During this period, parameters such as temperature, relative humidity, CO2, supply air flow rate, and room air velocities are measured on site. The results of the measurement show that the indoor temperature is on average lower in the rooms facing north, at 21–23.5 °C, compared to the rooms facing south, which reach high temperatures during sunny days, up to 26 °C. The results also show that the ventilation air supply rate is lower than the requirement for offices in two of the office rooms. The ACH rate is also low, at ≈ 1 h−1 for all the rooms, compared to the required levels of 2–4 h−1. The CO2 levels are within the recommended values; on average, the highest is in one of the south-facing rooms, with 768 ppm, and the maximum measured value is also in the same room, with 1273 ppm for a short period of time.

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  • 136.
    Amelin, Mikael
    KTH, School of Electrical Engineering (EES), Electric Power Systems.
    An Evaluation of Intraday Trading and Demand Response for a Predominantly Hydro-Wind System Under Nordic Market Rules2015In: IEEE Transactions on Power Systems, ISSN 0885-8950, E-ISSN 1558-0679, Vol. 30, no 1, p. 3-12Article in journal (Refereed)
    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.

  • 137.
    Amiri, Shahnaz
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Linköpings universitet, Institutionen för ekonomisk och industriell utveckling, Energisystem.
    Economic and Environmental Benefits of CHP-based District Heating Systems in Sweden2013Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Future energy systems and thus the climate are affected by many factors, such as energy resources, energy demand, energy policy and the choice of energy technologies. Energy systems of the future are facing three main challenges; the steady growth of global energy demand, the energy resource depletion, as well as the increasing emissions of carbon dioxide (CO2) and other greenhouse gases and their impact on climate change. To meet the mentioned challenges with sustainability in mind, actions that increase energy efficiency and choosing an energy-efficient energy system which is cost efficient will be essential. Combined heat and power (CHP) plants and district heating and cooling could contribute greatly to increased system efficiency by using energy otherwise wasted.

    The aim of this study is to increase the understanding of how CHP-based district heating and cooling systems using different primary energy sources can contribute to more cost-efficient energy systems, which reduce global CO2 emissions, and to highlight the impact of some important parameters and measures on Swedish municipal district heating systems. An important assumption in this study is the estimation of CO2 emissions from electricity production, which is based on marginal electricity perspectives. In the short term, the marginal electricity is assumed to come from coal-fired condensing power plants while in the long term it consists of electricity produced by natural gas-fired combined cycle condensing power plants. This means that the local electricity production will replace the marginal electricity production. The underlying assumption is an ideal fully deregulated European electricity market where trade barriers are removed and there are no restrictions on transfer capacity.

    The results show that electricity generation in CHP plants, particularly in higher efficiency combined steam and gas turbine heat and power plants using natural gas, can reduce the global environmental impact of energy usage to a great extent. The results confirm, through the scenarios presented in this study, that waste as a fuel in CHP-based district heating systems is fully utilised since it has the lowest operational costs. The results also show how implementation of a biogas-based CHP plant in a biogas system contributes to an efficient system, as well as lowering both CO2 emissions and system costs. The results show that replacing electricity-driven (e.g. compression) cooling by heat-driven cooling using district heating (e.g. absorption chillers) in a CHP system is a cost-effective and climate friendly technology as electricity consumption is reduced while at the same time the electricity generation will be increased. The results of the study also show that there is potential to expand district heating systems to areas with lower heat density, with both environmental and economic benefits for the district heating companies.

    The results reveal that the operation of a studied CHP-based district heating system with an imposed emission limit is very sensitive to the way CO2 emissions are accounted, i.e., local CO2 emissions or emissions from marginal electricity production. The results show how the electricity production increases in the marginal case compared with the local one in order to reduce global CO2 emissions. The results also revealed that not only electricity and fuel prices but also policy instruments are important factors in promoting CHP-based district heating and cooling systems. The use of electricity certificates has a large influence for the introduction of biogas-based cogeneration. Another conclusion from the modelling is that present Swedish policy instruments are strong incentives for cogeneration with similar impact as applying external costs.

  • 138.
    Amiri, Shahnaz
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy engineering. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Henning, Dag
    Optensys Energianalys, Linköping, Sweden .
    Karlsson, Björn G.
    Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden .
    Simulation and introduction of a CHP plant in a Swedish biogas system2013In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 49, p. 242-249Article in journal (Refereed)
    Abstract [en]

    The objectives of this study are to present a model for biogas production systems to help achieve a more cost-effective system, and to analyse the conditions for connecting combined heat and power (CHP) plants to the biogas system. The European electricity market is assumed to be fully deregulated. The relation between connection of CHP. increased electricity and heat production, electricity prices, and electricity certificate trading is investigated. A cost-minimising linear programming model (MODEST) is used. MODEST has been applied to many energy systems, but this is the first time the model has been used for biogas production. The new model, which is the main result of this work, can be used for operational optimisation and evaluating economic consequences of future changes in the biogas system. The results from the case study and sensitivity analysis show that the model is reliable and can be used for strategic planning. The results show that implementation of a biogas-based CHP plant result in an electricity power production of approximately 39 GW h annually. Reduced system costs provide a profitability of 46 MSEK/year if electricity and heat prices increase by 100% and electricity certificate prices increase by 50%. CO2 emission reductions up to 32,000 ton/year can be achieved if generated electricity displaces coal-fired condensing power.

  • 139.
    Amiri, Shahnaz
    et al.
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. University of Gavle, Sweden.
    Weinberger, Gottfried
    University of Gävle, Sweden.
    Increased cogeneration of renewable electricity through energy cooperation in a Swedish district heating system - A case study2018In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 116, p. 866-877Article in journal (Refereed)
    Abstract [en]

    The present study of the district heating (DH) system in the city of Kisa, Sweden, shows how, through energy cooperation with a nearby sawmill and paper mill, a local energy company contributes to energy efficient DH and cost-effective utilization of a new biofuel combined heat and power (CHP) plant. Cases of stand-alone and integrated energy systems are optimized with the linear program MODEST. The European power market is assumed to be fully deregulated. The results show clear advantages for the energy company to cooperate with these industries to produce heat for DH and process steam for industry. The cooperating industries gain advantages from heat and/or biofuel by-product supply as well. The opening to use a biofuel CHP plant for combined heat supply results in cogenerated electricity of almost 29 GWh/a with an increased biofuel use of 13 GWhia, zero fuel oil use and CO2 emission reductions of 25,800 tons CO2/a with coal-condensing power plant on the margin and biofuel as limited resource. The total system cost decreases by -2.18 MEUR/a through extended cooperation and renewable electricity sales. The sensitivity analysis shows that the profitability of investing in a biofuel CHP plant increases with higher electricity and electricity certificate prices. (C) 2017 Elsevier Ltd. All rights reserved.

  • 140.
    Amiri, Shahnaz
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system. Department of Management and Engineering, Division of Energy Systems, Linköping University, Linköping, Sweden.
    Weinberger, Gottfried
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Building, Energy and Environmental Engineering, Energy system.
    Increased cogeneration of renewable electricity through energy cooperation in a Swedish district heating system - A case study2018In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 116, p. 866-877Article in journal (Refereed)
    Abstract [en]

    The present study of the district heating (DH) system in the city of Kisa, Sweden, shows how, through energy cooperation with a nearby sawmill and paper mill, a local energy company contributes to energy-efficient DH and cost-effective utilization of a new biofuel combined heat and power (CHP) plant. Cases of stand-alone and integrated energy systems are optimized with the linear program MODEST. The European power market is assumed to be fully deregulated. The results show clear advantages for the energy company to cooperate with these industries to produce heat for DH and process steam for industry. The cooperating industries gain advantages from heat and/or biofuel by-product supply as well. The opening to use a biofuel CHP plant for combined heat supply results in cogenerated electricity of almost 29 GWh/a with an increased biofuel use of 13 GWh/a, zero fuel oil use and CO2 emission reductions of 25,800 tons CO2/a with coal-condensing power plant on the margin and biofuel as limited resource. The total system cost decreases by −2.18 MEUR/a through extended cooperation and renewable electricity sales. The sensitivity analysis shows that the profitability of investing in a biofuel CHP plant increases with higher electricity and electricity certificate prices.

  • 141. Ammenberg, J.
    et al.
    Anderberg, S.
    Lönnqvist, Tomas
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Grönkvist, Stefan
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Sandberg, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Industrial Economics and Management (Dept.).
    Biogas in the transport sector—actor and policy analysis focusing on the demand side in the Stockholm region2018In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 129, p. 70-80Article in journal (Refereed)
    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.

  • 142.
    Ammenberg, Jonas
    et al.
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Marcus
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    O’Shea, Richard
    MaREI Centre, Environmental Research Institute, University College Cork, Ireland.
    Gray, Nathan
    MaREI Centre, Environmental Research Institute, University College Cork, Ireland.
    Lyng, Kari-Anne
    NORSUS, Norwegian Research Institute for Sustainability Research.
    Eklund, Mats
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Murphy, Jerry D.
    MaREI Centre, Environmental Research Institute, University College Cork, Ireland.
    Perspectives on biomethane as a transport fuel within acircular economy, energy, and environmental system2021Report (Other academic)
    Abstract [en]

    The literature indicates that the life cycle costs of biomethane fueled light vehicles may be 15 to 20% highe rthan for similar petrol and diesel fueled vehicles, while liquid biomethane fueled heavy duty trucks may have similar life cycle costs to diesel. However, such an analysis can be two dimensional and limited in the message it conveys. On one hand the acceptance of diesel fueled trucks and buses will be limited due to the climate emergency and air pollution and after 2030 diesel may not be the competition for biomethane anymore. On the otherhand, biomethane production is part of a larger circular economy, energy, and environmental system. It is verydifficult to divorce the energy vector, biomethane, from the system through which it is produced. In essence biomethane can be considered as one of the products or services of a broad biogas system.

    An advantage of biogas is that it can be produced from most wet organic wastes or by-products, includingfor food waste, animal by-products, (such as manure), agricultural residues, sewage sludge, industrial biowaste (such as from slaughterhouses and food and beverage processing industries). Biogas production is an element in the environmental management of such wastes; biogas plants can also deliver digestate, which contains most ofthe nutrients in the feedstock and can be an excellent biofertilizer. In addition, it is possible to utilize the carbon dioxide removed in upgrading biogas to biomethane as a product with added value. The resource of biomethane is very significant in considering the vast amounts of organic wastes landfilled around the world each year, that instead could be used to produce biogas, biofertilizers and food grade CO2 while improving the environment through reduced fugitive methane emissions and improved water quality. Furthermore, the application of biogas systems in bio-industrial contexts (such as paper mills, food production facilities, or other types of biorefineries) has huge potential to decarbonize industry while significantly increasing the resource of biomethane. Due to the multifunctionality of biomethane solutions, broad assessment methods are needed to grasp thewide spectrum of relevant factors when comparing different technologies:

    • Biomethane has a competitive performance compared with fossil fuels and other biofuels on a whole lifecycle analysis and is particularly suited to long distance heavy vehicles.

    • Biomethane from manure, residues, waste & catch crops is estimated to have low GHG emissions ascompared to other renewable fuels.

    • Biomethane may contribute to reduced air pollution in comparison with diesel, petrol, and other biofuels.• Biomethane can contribute to a substantial reduction in acidification compared with fossil fuels.

    • Biomethane may contribute to significantly reduced noise levels in comparison with diesel heavy goodsvehicles.

    • Well-designed and applied biogas systems may be essential to transform conventional farming to moresustainable farming and to organic farming.

    • Common types of biogas solutions provide essential sociotechnical systems services as components ofsystems for waste and (waste) water management.

    • Biogas solutions may importantly contribute to improved energy supply/security and flexibility.

    Natural gas systems should be a facilitator of the introduction of biomethane for transport, but the sustainability problems associated with natural gas negatively impact the view of biomethane. This is where arguments amongst the renewable sector actors can hinder progress. Biomethane and (power to methane) can utilize the existing gas grid and accelerate progress to decarbonization of the overall energy sector beyond just electricity and also to decarbonize chemical (such as ammonia and methanol) and steel production. This should be advantageous especially when realizing that more energy is procured from the natural gas grid than the electricity gridin the EU and the US; however, suggestions that biomethane is only greenwashing the natural gas industry, and in doing so extending the lifetime of natural gas, greatly impedes this progress.

    This report provides exemplars of very good biomethane based transport solutions, with a high technologicalreadiness level for all elements of the chain from production to vehicles. Transport biomethane sits well in the broad circular economy, energy, and environmental system providing services across a range of sectors including reduction in fugitive methane emissions from slurries, treatment of residues, environmental protection, provision of biofertiliser, provision of food grade CO2 and a fuel readily available for long distance heavy haulage. What we do not have is time to postpone the sustainable implementation of such circular economy biomethane systems as the climate emergency will not wait for absolutely perfect zero emission solutions; should they exist.

  • 143.
    Ammon, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid State Physics.
    Comparing the benefits of energy saving measures with seasonal solar thermal heat storage2014Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This thesis compares the effects of energy saving measures with Active Solar Energy

    Storage (ASES) on a property owned by Stena Fastigheter. The building is located in

    Lövgärdet in Gothenburg and was a part of the Million Homes Program. It was built in 1967, has 9 floors, a heated basement and is heated by district heating. The thermal envelope of the building consists of the walls, doors, windows, roof/attic and the basement.

     

    ASES is a system consisting of solar panels on the roof of a building connected to the heating system. The solar energy that cannot be used immediately is stored in a ground storage unit for when it is needed. ASES can also be supplemented by geothermal heating by drilling boreholes into the ground and, via a Ground Source Heat Pump (GSHP), using the heat in the underlying rock.

     

    The ASES and GSHP system combined were compared to energy saving measure on the thermal envelope in terms of reducing the need for purchased energy and increasing profitability. The energy saving measures were: changing the 2-pane windows to 3-pane windows (either by adding a window pane or changing to a 3-pane window), insulating the façade, insulating the attic, insulating and draining the basement, changing doors, replacing the heat exchanger with a more efficient one, and improving ventilation system. The new system, called FTX, reuses the heat from the exhaust air to save energy.

     

    The results of the thesis show that it is difficult to make energy saving measures profitable. Of the measures evaluated, draining and insulating the basement is extremely cost effective, with a payback time of less than two years. Other profitable measures are insulating the walls (renovation costs of the wall excluded) and insulating the attic, but with a much longer payback time. The ASES and GSHP system are profitable and greatly reduced the need for purchased energy, but require a long payback time. The sum of all energy saving measures does not reduce the need for purchased energy as much, or as cheaply, as ASES, which reduced the energy usage by 62 %.

     

    Due to limited solar panel area ASES cannot supply enough heat to cover the heat demand of the studied building. ASES is therefore believed to be better suited for the buildings that surround the evaluated building. The surrounding buildings have fewer storeys, larger roof area where solar panels can be mounted, and open areas better suited for the ground storage. The potential to implement the ASES system for buildings like these from the Million Homes Program should be evaluated further.

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  • 144.
    Anacleto, Thuane Mendes
    et al.
    Univ Fed Rio de Janeiro, Brazil; Univ Fed Rio de Janeiro, Brazil.
    Kozlowsky-Suzuki, Betina
    Univ Fed Estado Rio de Janeiro, Brazil.
    Wilson, Alan E.
    Auburn Univ, AL 36849 USA.
    Enrich Prast, Alex
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Univ Fed Rio de Janeiro, Brazil; Fed Univ Sao Paulo IMar UNIFESP, Brazil.
    Comprehensive Meta-Analysis of Pathways to Increase Biogas Production in the Textile Industry2022In: Energies, E-ISSN 1996-1073, Vol. 15, no 15, article id 5574Article in journal (Refereed)
    Abstract [en]

    The textile industry is one of the largest environmental polluters in the world. Although waste management via anaerobic digestion (AD) is a sustainable strategy to transform waste into clean energy and water recovery, the efficiency of the AD process is reduced by the presence of recalcitrant materials, chemicals, and toxic contents. This study aims to investigate the performance of several chemical, physical, and biological pretreatments applied to improve the biodegradability of textile waste. We performed a meta-analysis with 117 data extracted from 13 published articles that evaluated the efficiency of pretreatments applied to textile waste prior to AD to increase biogas production measured as methane (CH4) yield. Even though the majority of the studies have focused on the effect of chemical and physical pretreatments, our results showed that the application of biological pretreatments are more efficient and eco-friendlier. Biological pretreatments can increase CH4 yield by up to 360% with lower environmental risk and lower operating costs, while producing clean energy and a cleaner waste stream. Biological pretreatments also avoid the addition of chemicals and favor the reuse of textile wastewater, decreasing the current demand for clean water and increasing resource circularity in the textile industry.

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  • 145.
    Anacleto, Thuane Mendes
    et al.
    Univ Fed Rio de Janeiro, Brazil.
    Oliveira, Helena Rodrigues
    Univ Fed Rio de Janeiro, Brazil.
    Diniz, Vinicius Lacerda
    Univ Fed Rio de Janeiro, Brazil.
    de Oliveira, Vinicius Peruzzi
    Univ Fed Rio de Janeiro, Brazil.
    Abreu, Fernanda
    Univ Fed Rio de Janeiro, Brazil.
    Enrich-Prast, Alex
    Linköping University, Department of Thematic Studies, Tema Environmental Change. Linköping University, Faculty of Arts and Sciences. Linköping University, Biogas Research Center. Univ Fed Rio de Janeiro, Brazil; Fed Univ Sao Paulo IMar UNIFESP, Brazil.
    Boosting manure biogas production with the application of pretreatments: A meta-analysis2022In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 362, article id 132292Article in journal (Refereed)
    Abstract [en]

    Anaerobic digestion (AD) is a versatile manure management approach that can combine waste treatment, energy generation and nutrient recovery, thus playing a central role in circular economy. The AD process is highly influenced by manure composition which, depending on the source, may contain high loads recalcitrant materials (e.g., lignocellulosic and fibers) or lead to the formation of toxic compounds (e.g., NH3), decreasing the energetic potential of the waste and requiring specific pretreatments to increase its degradability and biogas production. Although there are distinctions in the chemical composition of manure according to animal diets, different manure sources are usually grouped together, leading to a suboptimal performance of both the pretreatment and the AD process. Here, we performed a meta-analysis of 54 studies to evaluate the effects of different pretreatments on different manure types and their effect on methane (CH4) yield and we estimated the energy potential if the appropriate pretreatment is applied to largest manure producing countries. The results showed that chemical and/or biological pretreatments were more effective for omnivore manure (e.g., swine, chicken), while physical and a combination of chemical and physical pretreatments negatively affected CH4 production. Physical and/or chemical pretreatments had a positive effect on CH4 yield from herbivore manure (e. g., cattle, horses), while biological pretreatments had a negative effect. The application of the adequate pretreatment can more than double the energy recovered from manure, allowing for an important substitution of fossil fuels, while decreasing operational costs and environmental risks and ultimately improving profitability. The development of pretreatment technologies and their application are strongly related to public policies for sustainable manure management and biogas use and production.

  • 146.
    Ancel, Julie
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Heat and Power Technology.
    Improvement of the electrical part of Idénergie's hydrokinetic turbine2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    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.

  • 147.
    Andersen, Martin
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology. Chalmers University of Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Dalenbäck, Jan-Olof
    Chalmers University of Technology.
    Techno-Economic Analysis of Solar Options for a Block Heating System2016In: Conference Proceedings: Eurosun 2016, Palma De Mallorca: International Solar Energy Society, 2016, , p. 16Conference paper (Refereed)
    Abstract [en]

    An innovative small solar district heating system with one central heating plant and four solar substations has been built in Vallda Heberg, Sweden, to supply a new housing area with passive houses. The target solar fraction was 40% and the total system design, including heat distribution in the buildings, was based on previous experience and aimed to be simple and cost-effective. The main aim of this study was to determine whether the system can be designed in a more effective manner by change of distribution system and load density. TRNSYS models were calibrated against measured data and then used to predict the energy performance. Results indicate that lower distribution heat losses can be obtained by change to a distribution concept with lower operating temperatures, while potentially reducing cost. Changes in heat density cause reduced distribution losses and boiler supplied heat demand, with only minor effects on solar system yield.

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  • 148.
    Andersen, Niklas
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Ismail, Zahir
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Solel från ljudbarriär: längs Annetorpsvägen i Hyllie, Malmö2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    City of Malmö has ambitions for the district Hyllie to become a demonstrative area ofsustainable urban development. As a part of this the following report aims to investigate the potential in using noise barriers combined with photovoltaics along Annetorpsvägen to generate solar electricity. To quantify the losses that shadows from buildings along the roadmight cause, a 3D-model of the area was constructed in SketchUp. This digital model made it possible to simulate shadows and how they change over the year. A reference model of a photovoltaic noise barrier (PVNB) was constructed and used to find the dates on which the solar cells are shadowed depending on building heights and positioning of the barrier.

    The results show that two lengths with a total distance of 400 meters is appropriate for applying photovoltaic noise barriers. Along distance A, a PVNB with a total capacity of 19 kWp is expected to generate 18 000 kWh per year assuming realistic shadowing, which equals 6% losses compared to production without shadows. The PVNB along distance B with installed capacity of 37 kWp has no considerable problems with shadowing and is expected to generate 37 500 kWh per year. This gives a total production of 56 500 kWh per year.

    The combined investment costs (excluding costs for the actual noise barrier) for both power plants are assumed to be approximately one million SEK. Expected economical outcome is a negative capital value after 25 years, although a change of critical factors such as investment aid, investment cost, electricity prices and cost of capital may result in a more positive outcome. Production losses from shadowing and dirt seem to have a minimal effect on the outcome

    Despite uncertainty in the economical outcome, realizing the project would have several other positive effects such as reduction of carbon dioxide emissions and a positive impact on the public view of renewable energy.

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  • 149. Anderson, L. G.
    et al.
    Björk, G.
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Kattner, G.
    Koltermann, P. K.
    Jones, E. P.
    Lindegren, R.
    Rudels, B.
    Swift, J.
    Water masses and circulation in the Eurasien Basin: Results from the Oden 91 expedition1994In: Journal of Geophysical Research, Vol 99, No. C2: 3273-3283Article in journal (Refereed)
  • 150. Anderson, Leif G.
    et al.
    Holby, Ola
    Karlstad University, Faculty of Technology and Science, Department of Energy, Environmental and Building Technology.
    Ohlson, Mats
    Lindegren, Roger
    The transport of anthropogenic carbon dioxid into the Weddell sea1991In: Journal of Geophysical Research, Vol 96, No. C9: 16,679-16,687Article in journal (Refereed)
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