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  • 1.
    Adolfsson, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Expanding operation ranges using active flow control in Francis turbines2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report contains an investigation of fluid injection techniques used in the purpose of reducing deleterious flow effects occurring in the draft tube of Francis turbines when operating outside nominal load. There is a focus on implement ability at Jämtkrafts hydroelectric power plants and two power plants were investigated, located in series with each other named Lövhöjden and Ålviken. The only profitable scenario found with some degree of certainty was an increase in the operating range upwards to allow overload operation.

    Findings show that both air and water can be introduced in various locations to improve hydraulic efficiency around the turbine parts as well as reduce pressure pulsations in harmful operating regions. Investments in such systems have proven useful and profitable at several facilities with poorly adapted operating conditions. But due to losses in efficiency when operating injection systems, it turns out unprofitable in situations where it does not improve the operating range in a way that is resulting in increased annual or peak production.

  • 2.
    Allard, Ingrid
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Achieving building energy performance: requirements and evaluation methods for residential buildings in Sweden, Norway, and Finland2015Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Building energy performance has always been important in the cold climate of Sweden, Norway and Finland. To meet the goal that all new buildings should be nearly zero-energy buildings by 2020, set in the EU directive 2010/31/EU [1] on the energy performance of buildings (EPBD recast), the building sector in Europe now faces a transition towards buildings with improved energy performance. In such a transition, a discussion is needed about the objective of the improvement – why, or to what end, the building energy performance should be improved. The objective of improving building energy performance is often a political decision, but scientific research can contribute with knowledge on how the objectives can be achieved.

    This thesis addresses how the indicators used in the requirements used to achieve building energy performance in Sweden, Norway, and Finland, and the methods used to evaluate these requirements, reflect building energy performance. It also addresses difficulties in achieving comparable and verifiable indicators in evaluations of building energy performance. The research objective has two parts: to review, compare, and discuss (i) requirements and (ii) evaluation methods used to achieve energy performance of residential buildings in Sweden, Norway and Finland. The work in this thesis includes reviews of the requirements used in national building codes and passive house criteria to achieve building energy performance, of methods used to evaluate compliance with such requirements, and of methods used specifically to evaluate the indicator Envelope Air Tightness.

    The results show that different sets of indicators are used to achieve building energy performance in the studied building codes and passive house criteria. The methods used to evaluate compliance with requirements used to achieve building energy performance are also different, but calculation methods are generally more often used than measurement methods. The calculation- and measurement methods used are often simple. A methodology to analyze the deviation between predictions- and measurements of building energy performance (the performance gap) was developed, to investigate the effects of different evaluation methods on different indicators used to achieve building energy performance. The methodology was tested in a case-study. This study indicated that the choice of method affects which parts of the performance gap reflected in the indicators Supplied Energy (see Terminology), Net Energy (see Terminology), and Overall U-value. Among the reviewed methods to evaluate air tightness, the Fan/Blower Door Pressurization is well known and preferred by professionals in the field. The results in this thesis may be useful when choosing indicators and evaluation methods to achieve different objectives of improving building energy performance and in the quest towards comparable and verifiable indicators used to achieve building energy performance.

  • 3.
    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
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Methods for air tightness analysis for residential buildings in Nordic countries2012In: Methods for air tightness analysis forresidential buildings in Nordic countries, Southampton: WIT Press, 2012, p. 311-322Conference paper (Refereed)
    Abstract [en]

    Envelope air tightness is one factor that has impact on the energy performance ofbuildings. The goals of the directive 2010/31/EU, on energy performance ofbuildings, raise the importance of building energy performance analysis in theprocess. Measurements of air tightness can be useful both when evaluatingbuilding energy performance and developing new building techniques. The aimof this paper is to review and evaluate methods to measure air tightness in bothnew and existing residential buildings in Sweden, Norway and Finland, based onan international literature study and a survey. The methods are categorized basedon a number of criteria to determine their suitability in different situations.Advantages and disadvantages of the methods are discussed, as well ascommonly used methods in the three countries. The review shows that thestandard ISO 9972 is used for verification in all three countries, but alternativesexist that might be more suitable in certain situations. Simpler methods are usedin the building process to increase air tightness. To achieve a comparablemeasurement, both common methods and commonly defined units are needed.

  • 4.
    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.

  • 5.
    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, ISSN 2071-1050, 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.

  • 6.
    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.

  • 7.
    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. 

  • 8. Anderssen, C.
    et al.
    Lindgren, R.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Carvalho, R.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Malmborg, V.
    Ahlberg, E.
    García-López, N.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Eriksson, A.
    Kristensen, T.B.
    Svenningsson, B.
    Boman, C.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Pagels, J.
    SOA Formation and Particle Characteristics in the Emissions from Biomass Cook Stoves Used in the Developing Countries2017In: SOA Formation and Particle Characteristics in the Emissions from Biomass Cook Stoves Used in the Developing Countries, 2017Conference paper (Refereed)
  • 9.
    Andersson, Erik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utvärdering av möjligheten att tillvarata energi ur processvatten: En undersökning gjort vid Olofsfors AB på uppdrag av UMIA AB.2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The company Olofsfors AB manufactures drive belts for forest machinery, known as ECO-Tracks, and abrasion-resistant steel and cutting edges for graders, excavators and tractors, known as Bruxite and SharqEdges. Manufacturing these products requires the steel to be heated and molded, then submerged in water and hardened. The water used in the hardening of steel is pumped to the process from pits below the floor and then pumped back to the pit after it’s been used. Since the temperature of this water rises after being used to harden the steel the temperature of the pumping pit needs to be adjusted to maintain its setpoint of 21°C. This is done by disposal of hot water from the pit to the river outside while new, cold water, from the river is pumped into the pit. The hot water that is being disposed of contains energy that has not at all been utilized, this has led to the purpose of this report which is to examine the possibility to utilize parts of the energy in the water.

     

    Two possible outlets for the energy at the plant has been selected as especially interesting: • Heating of ventilation supply air in two units with low thermal efficiency and relatively high airflows where the supply air temperature is to be increased from 9 °C to 15 °C. • Fan heaters installed with electric batteries of approximately 200 kW capacity, which heats the premises and serves as an air barrier at the intake ports for metal.

     

    Calculations of power available in one of the factory pump pits during the heating season from October to May and the power required for deposition areas were made. The result obtained is illustrated by means of duration charts from which required and available energy is deduced.

     

    The result of this:

    Pump pit                             887 MWh / October to May

    Ventilation                          642 MWh / year

    Fan heaters                         515 MWh / year

     

    A draft measure has been developed in which two heat pumps delivers hot water for heating of both the ventilation supply air and liquid batteries in air fan heaters. This measure proposal means a cost saving of approximately 390 000 SEK / year where pay-off time of the investment is approximately 5 years.

  • 10.
    Arnoldsson, Kristina
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Andersson, Patrik L
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Haglund, Peter
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Formation of environmentally relevant brominated dioxins from 2,4,6,-tribromophenol via bromoperoxidase-catalyzed dimerization2012In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 46, no 13, p. 7239-7244Article in journal (Refereed)
    Abstract [en]

    Polybrominated dibenzo-p-dioxins (PBDD) are emerging environmental pollutants with structural similarities to the highly characterized toxicants polychlorinated dibenzo-p-dioxins. The geographical and temporal variations of PBDD in biota samples from the Baltic Sea do not display features that are normally related to anthropogenic sources such as incineration, and therefore the natural formation of PBDDs has been suggested. This study of the bromoperoxidase mediated oxidative coupling of 2,4,6-tribromophenol (an abundant substance that is naturally formed in marine systems) identified the formation of ppb-level yields of 1,3,6,8-tetrabromodibenzo-p-dioxin (1,3,6,8-TeBDD) through direct condensation. Additional TeBDDs (1,3,7,9-TeBDD, 1,2,4,7-TeBDD and/or 1,2,4,8-TeBDD) and tri-BDDs (1,3,7-TrBDD and 1,3,8-TrBDD) were frequently formed, but at lower yields. The formation of these TeBDDs probably proceeds via bromine shifts or Smiles rearrangements, while the TrBDDs may result from subsequent debromination processes. Since all of the congeners formed by oxidative coupling and subsequent reactions are also found in Baltic Sea biota, the results support the theory that PBDDs are formed from natural precursors.

  • 11. Asthana, Arvind
    et al.
    Nair, Gireesh
    ?.
    Big efficiency in small scale2001Other (Other (popular science, discussion, etc.))
  • 12.
    Axelsson, Sebastian
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utredning av en potentiell installation av FTX-ventilation med värmeåtervinning2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The main purpose of this degree project is to study and investigate a specific existing building to contribute to promoting a sustainable future on a larger scale. At the same time, shows that in many cases it can also be profitable to invest in a new energy-efficient system. After studying the structure and existing system of the building, it was found that a new ventilation system would be relevant.

    The building holds 83 apartments on a total area of 5 474 m2 and is located in northern part of Sweden, where temperatures of -30 °C are commen during winter time. The property is currently run by an exhaust air system for transporting consumed air, fresh air flows through outside valves directly into the recidence. Because the property is located in a place where cold outdoor temperatures occur many times a year, it's unlikely to transport cold air directly into the dwelling without preheating. This means that the current district heating consumption of the radiators will achieve unacceptable high values to maintain a good indoor envirement.

    The project that has been implemented shows that there are primarily an opportunity to install an FTX system in the homes. In many cases, there are a lack of space that contradicts an installation. Apart from the space, the result shows that district heating can be reduced by up to 600 MWh per year. This would mean a saving of 411 KSEK per year for the entire property. The cost of the required material is estimated at approximately 3.1 MSEK. This means that the investment is repaid after about 7-8 years. The figures mentioned above correspond to the material package that is reported in the report's results and assumes that existing air ducts present in the accommodation today remain but expanded. The design of the proposal presented is based on a balanced ventilation with heat recovery (80 %) with separate units for each apartement.

  • 13.
    Azizi, Shoaib
    et al.
    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.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Analysing the house-owners’ perceptions on benefits and barriers of energy renovation in Swedish single-family houses2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 198, p. 187-196Article in journal (Refereed)
    Abstract [en]

    Single-family houses offer a large potential for energy savings by energy renovation (ER). Homeowners’ motivation to implement ER derives from the benefits and barriers they perceive. Benefits are the positive consequences that can motivate homeowners to act and barriers are the challenges that demotivate them to undertake ER. Different benefits and barriers do not homogenously affect every homeowner. Identifying motivating benefits and demotivating barriers for each specific group among homeowners can shed lights on ER decision-making and enable policies that are more effective. The objective of this study is to contextualize the implementation of ER by understanding how the perceived benefits and barriers influence homeowners. This study links the expected consequences, which are benefits and barriers to the influential factors on ER, which are used to group the homeowners.

    The analysis is based on a questionnaire survey mailed to 1550 owners of single-family houses in northern Sweden. The perceptions of homeowners on benefits and barriers of ER are significantly different between the groups that are motivated and unmotivated to implement ER. Despite the perceived importance of some of the benefits such as energy cost reduction, they may not be determinative for the homeowners’ decision to undertake ER. The homeowners are more likely to implement ER for reasons other than energy use reduction such as for improving the indoor environment. The barriers such as the difficulty of finding a low-interest loan and reliable information sources are found to impede the intention to implement ER among different groups. Policy implications to facilitate ER in single-family houses are discussed.

  • 14.
    Azizi, Shoaib
    et al.
    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.
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Demand-controlled energy systems in commercial and institutional buildings: a review of methods and potentials2019In: eceee 2019 Summer Study on energy efficiency:: Is efficient sufficient?, European Council for an Energy Efficient Economy (ECEEE), 2019, p. 1444-1450Conference paper (Refereed)
    Abstract [en]

    Heating, ventilation and air-conditioning (HVAC) are by farthe most energy intensive systems in commercial and institutionalbuildings with office spaces. This makes HVAC systemsattractive targets for energy efficiency improvement. New technologicaladvancements can play significant role on improvingenergy efficiency. Such advancements have been also emergedin form of novel management and control strategies, whichmight lead to considerable energy savings with relatively minorinvestments. This paper evaluates demand control HVAC andlighting to assess the energy saving potential of upgrading theconventional building energy systems.

    This paper provides a summary of different methods and occupancydetection technologies. A range of technologies andmethods are covered that vary in complexity, limitations andenergy saving potential. Additional benefits such as demandresponse are evaluated and other emerging applications arediscussed. Based on the review of methods and potentials, thepaper assesses the state of the art in demand controlled energysystems and suggests areas for further research.

  • 15.
    Berglund, Tomas
    et al.
    Algoryx Simulation AB.
    Mickelsson, Kjell-Ove
    LKAB.
    Servin, Martin
    Umeå University, Faculty of Science and Technology, Department of Physics. Algoryx Simulation AB.
    Virtual commissioning of a mobile ore chute2018Conference paper (Other academic)
    Abstract [en]

    This paper describes the virtual commissioning of a mobile ore chute for sequential loading of trucks from a conveyor system with a continuous material flow. The design and control were tested in simulation environment and improved prior to its installation in an underground mine in full production. The altered design met the performance goal and the amount of rock spill and wear on surrounding equipment could be reduced significantly. The simulations were based on a novel combination of discrete element and multibody simulation using a nonsmooth dynamics formulation, integrated in a 3D modeling software. This enable both fast simulation, based on original CAD drawings, and high flexibility in modifying the design and control.

  • 16.
    Broberg, Thomas
    et al.
    Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Economics. Umeå University, Faculty of Social Sciences, Centre for Environmental and Resource Economics (CERE).
    Egüez, Alejandro
    Umeå University, Faculty of Social Sciences, Centre for Environmental and Resource Economics (CERE). Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Economics.
    Kazukauskas, Andrius
    Umeå University, Faculty of Social Sciences, Centre for Environmental and Resource Economics (CERE). Umeå University, Faculty of Social Sciences, Umeå School of Business and Economics (USBE), Economics. Vilnius University.
    Effects of energy performance certificates on investment: A quasi-natural experiment approach2019In: Energy Economics, ISSN 0140-9883, E-ISSN 1873-6181Article in journal (Refereed)
    Abstract [en]

    Incomplete information may be one reason why some households do not invest in energy efficiency even though it would benefit them to do so. Energy performance certificates (EPCs) have been promoted to overcome such information shortages. In this paper, we investigate whether EPCs together with mandatory home energy audits make households more likely to invest in energy efficiency. Our study takes advantage of the mandatory nature of the EPCs to avoid the potential selection bias problem that typically applies to studies using voluntary energy audits as the treatment. Our treatment group consists of single-household houses in Sweden sold from 2008, i.e., when EPCs became legally required in connection with sales of residential buildings, to 2015; while the control group consists of houses sold between 2002 and 2008, i.e., without an EPC. The results show that there is no statistically significant treatment effect for most of the measures that a household can take to improve the energy performance of their house. The significant treatment effect that we do find concerns a few heating system-related measures.

  • 17.
    Buckland, Philip I.
    et al.
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Nyqvist, Roger
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Alexander, Benedict
    WSP, Sweden.
    Palsson, Gisli
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    Eriksson, Samuel
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies, Environmental Archaeology Lab.
    The Swedish Transport Administration’s Toolbox and its Potential in Archaeological and Cultural Heritage Survey: Including a brief review of remote sensing, prospection and geodata analysis methods for archaeology and cultural heritage2018Report (Other academic)
    Abstract [en]

    This report provides an overview of the main remote sensing methods and geodata types used in archaeological prospection and cultural heritage survey. Based on a literature review, it provides an initial survey of the state of the art nationally and internationally, followed by details on the potential usage of different methods in a Swedish context. The details include pros and cons of methods as well as information on considerations that should be taken into account when applying the methods in different situations. Examples are provided where relevant to explain specific details or illustrate important points. Particular attention has been paid to laser scanning (LiDAR) data due to its increasing prevalence and prominence in landscape and archaeological surveys.

    The report continues with a preliminary evaluation of the possibilities for using data provided by Swedish Transport Administration (Trafikverket), obtained for other stages of the planning process, in archaeological and cultural heritage work. Specifically, the report looks at a number of geodata types obtained from The Geological Survey of Sweden (Sveriges geologiska undersökning/SGU), a nature conservation survey in report form, a ground penetrating radar technical report, terrain laser scanning (LiDAR) and orthophotos (geometrically corrected aerial photographs). The SGU geodata consist of a number of Geographical Information System (GIS) layers describing bedrock and soil types, and the nature conservation survey included accompanying, but incomplete, GIS data. This section consists of concise descriptions of the potential of each group of GIS layers or data, and is complemented by brief, bullet point summaries along with additional technical information in Appendix 1. Comments have been made where additional, related, data sources would be useful. Swedish terms are included in parenthesis where the term differs significantly from the English equivalent.

    A final summary provides a compact overview of the main points of the report before providing some conclusions and ideas for further work. This is in turn followed by a list of ideas for enhancing the efficiency with which the types of data discussed can be used in infrastructure projects which have a potential to impact on archaeology/cultural heritage.

    References are provided to support important or potentially contentious points or where further reading or research would be advised for a more comprehensive understanding of relevant issues.

  • 18.
    Burlin, Jesper
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Geoenergi med och utan värmepump2017Independent thesis Advanced level (professional degree), 300 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utfördes på uppdrag av Umeå Kommun. Uppgiften bestod av att utvärdera dagens användning av en borrhålsbrunn samt undersöka vad som är det optimala användningsområdet för borrhålsbrunnen. Borrhålsbrunnen används i dagsläget för att förvärma samt kyla utomhusluft in till kontorsbyggnaden Kubens ventilationsaggregat.

    Ventilationens förvärmning består av två delar, en markkanal och ett geoenergibatteri. Viktiga parametrar hos förvärmningen analyserades med hjälp av mätvärden för temperatur och flöde. Resultaten jämfördes därefter med alternativet att använda borrhålsbrunnen tillsammans med en värmepump. Då borrhålsbrunnens kapacitet inte var tillräcklig för att klara byggnadens hela uppvärmningsbehov, undersöktes det hur en värmepump skulle kunna köras i kombination med fjärrvärme. Två driftstrategier, Bas och Kapatoppar, undersöktes. Bas leverar en basproduktion under hela vinterperioden medan Kapatoppar startar vid -6°C för att sänka effekttoppar.

    Utvärderingen av förvärmningen visade att geoenergibatteriet är mer kompatibelt med ventilationsaggregat av VAV-typ (Variable Air Volume) än vad markkanalen är. Däremot är inte förvärmning i kombination med roterande värmeväxlare ett bra koncept för byggnaden som den används idag. På grund av att förvärmningen är placerad före den roterande värmeväxlaren så är bara 15-20 % av förvärmningseffekterna energibesparande. Detta kombinerat med en optimerad drift av aggregatet sett till tidsstyrning och behovsstyrning av flöde gör att förvärmningen har en liten påverkan både på byggnadens maximala effektbehov och totala energibehov.

    Att köra värmepump i kombination med fjärrvärme för uppvärmning var ekonomiskt lönsamt främst på grund av att värmepumpen kunde kapa byggnadens effektoppar. Kostnaden för storleken på den abonnerade effekten uppgår idag till drygt 40 % av den totala fjärrvärmekostnaden. Dagens relation mellan el- och fjärrvärmepriser bidrog naturligtvis också till att värmepumpsalternativet var lönsamt. För de undersökta förutsättningarna så blev paybacktiden för en värmepump med den lönsammaste driftstrategin, Bas, 4,4 år.

  • 19.
    Burman, Simon
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energianalys av MVG-gallerian, samt en jämförelse av beräkningsprogram2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This master thesis has been carried out in the spring of 2013, on behalf of Sweco Systems in Umeå. The aim of this work was to evaluate the possibilities of using any energy simulation software in the work of mapping energy usage of existing facilities. In this study two of the softwares that is being used in the company are evaluated – VIP-Energy and IDA Indoor Climate and Energy.

    Initially a mapping of the energy usage was performed on the property Odin 12 in Umeå, which consists mainly of the mall MVG. The energy usage was then simulated with the two different softwares.

    The mapping of energy usage shows that the building has a low annually need of space heating. This is due to the fact that the consumption of electricity in the building is very high, which leads to very high internal loads and a low need for additional heating. For the same reason, a need of space cooling is present during the whole year.

    The evaluation of the two energy simulation softwares shows that VIP-Energy is a suitable program for energy mapping. The program is both simple and flexible which reduces the time needed for creating the model.  Considering the time for the actual calculations, VIP-Energy is the program that is by far the fastest.

  • 20.
    Bäcklund, Johannes
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energieffektivisering av fjärrvärme- och fjärrkylanätet på campus i Umeå: Energy efficiency of the district heating and cooling systems on campus in Umeå2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utfördes på uppdrag av Akademiska Hus som äger och förvaltar fastigheterna på campus i Umeå. Projektet bestod av att utifrån en övergripande bild på det interna fjärrvärme- och fjärrkylanätet på campus, ta fram alternativa utformningar på systemet i syfte om att göra det mer energieffektivt.

    Systemets interna fjärrvärme- och fjärrkylanät VP100 och KB100 växlar över värme och kyla från Umeå Energi som sedan distribueras vidare till fjärrvärme- och fjärrkylacentraler på campus. Några av centralerna har egenproduktion där returledningen från KB100 går till en värmepump som producerar både värme och kyla. Producerad värme används till att förvärma returledningen från uppvärmningssystemen från de byggnader som hör till respektive central. När behovet av värme är tillräckligt stort är systemet, tack vare värmepumparna, självförsörjande gällande kyla. Produktion sker alltså endast under de perioder då det finns behov i uppvärmningssystemen. Det leder till att systemet tvingas köpa både värme och kyla samtidigt under sommaren då behovet av kyla i stort sett är konstant under året.

    Två alternativa utformningar till det befintliga systemet har undersökts. Det första fallet har som syfte att reducera värmeförlusterna i VP100. Det andra fallet byggdes vidare på det första fallet med syftet att utvidga arbetsområdet för värme- och kylproduktionen i värmepumparna.

    Resultatet visar att det finns potential att mer än halvera värmeförlusterna i det befintliga VP100 och att produktionen av värme och kyla skulle kunna öka med 10 % respektive 6 %. Totalt skulle systemet kunna spara drygt 1,3 miljoner kWh per år genom en kombination av de två alternativa utformningarna. För att däremot få energibalans i systemet där det aldrig behöver köpas både värme och kyla samtidigt bör andra effektiviseringsåtgärder övervägas. 

  • 21. Carter, Ellison
    et al.
    Lam, Nicholas
    Chafe, Zoe
    Carvalho, Ricardo
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Shan, Ming
    Ackerly, John
    Lancey, Forrest
    Household energy transitions to address air pollution exposure, health, and climate burdens associated with solid fuel burning2018In: Household energy transitions to address air pollution exposure, health, and climate burdens associated with solid fuel burning, Philadelphia, 2018Conference paper (Refereed)
    Abstract [en]

    Residential space heating and cooking are critical household energy service needs worldwide. Household transitions to clean-burning fuels at population scales are needed that do not contribute to poor indoor and outdoor air quality and the potential associated exposure, health, and climate burdens. We propose to discuss and debate research, implementation needs, and advances related to use of solid fuel for meeting residential energy needs with an express focus on residential heating demand, which has been less studied than residential cooking.We aim to identify knowledge gaps in the field of household energy systems in resource-constrained communities, set research priorities to address these gaps, and highlight opportunities for interdisciplinary and transnational learning and collaboration. 

  • 22.
    Carvalho, Ricardo L.
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Centre for Environmental and Marine Studies, Dept. of Environment and Planning, University of Aveiro, Aveiro, Portugal; Laboratory of Renewable Energy and Environmental Comfort, Institute of Education, Science and Technology of Ceará, Fortaleza, Brazil.
    Lindgren, Robert
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Lopez, N.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Nyambane, Anne
    Nyberg, Gert
    Diaz-Chavez, Rocio
    Boman, Christoffer
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Household air pollution mitigation with integrated biomass/cookstove strategies in Western Kenya2019In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 131, p. 168-186Article in journal (Refereed)
    Abstract [en]

    Traditional cooking is today's largest global environmental health risk. Over 640 million people in Africa are expected to rely on biomass for cooking by 2040. In Kenya, cooking inefficiently with wood and charcoal persists as a cause of deforestation and household air pollution. This research analyses the effects of four biomass cookstove strategies on reducing air pollutant emissions in Kisumu County between 2015 and 2035 using the Long-Range Energy Alternatives Planning system. The Business as Usual scenario (BAU) was developed considering the historical trends in household energy use. Energy transition scenarios to Improved Cookstoves (ICS), Pellet Gasifier Stoves (PGS) and Biogas Stoves (BGS) were applied to examine the impact of these systems on energy savings and air pollution mitigation. An integrated scenario (INT) was evaluated as a mix of the ICS, PGS and BGS. The highest energy savings, in relation to the BAU, are achieved in the BGS (30.9%), followed by the INT (23.5%), PGS (19.4%) and ICS (9.2%). The BGS offers the highest reduction in the GHG (37.6%), CH4 (94.3%), NMVOCs (85.0%), CO (97.4%), PM2.5 (64.7%) and BC (48.4%) emissions, and the PGS the highest reduction in the N2O (83.0%) and NOx (90.7%) emissions, in relation to the BAU.

  • 23.
    Carvalho, Ricardo
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Lindgren, Robert
    García-Lopez, Natxo
    Nyberg, Gert
    Boman, Christoffer
    Household Bioenergy Transitions with Alternative Biomass Feedstocks and Technologies: An Integrated System to Mitigate Environmental Risks in Western Kenya2018In: Household Bioenergy Transitions with Alternative Biomass Feedstocks and Technologies: An Integrated System to Mitigate Environmental Risks in Western Kenya / [ed] École Polytechnique Fédérale de Lausanne, UNESCO, Lausanne, 2018Conference paper (Refereed)
    Abstract [en]

    In Kenya, over 50% of the total primary energy consumption is from traditional solid-fuel cooking, being this a major cause of deforestation and household air pollution (HAP). Western Kenya has an agricultural biofuel feedstock of over 1.9 million Mt, which could be processed to supply cookstoves with crop-residue pellets and improved wood fallows. The sociotechnical viability of two novel bioenergy value chains were analysed using the Long-Range Energy Alternatives Planning system. Three scenarios of transition to efficient cookstoves and decentralized biofuel and electricity production systems were tested. In the “Optimal scenario”, the current feedstock in the Kisumu and Siaya counties could satisfy over 80% of the cooking energy demand by 2030. Here, the net greenhouse gas emissions from charcoal production and HAP could be reduced by 87% to 12.6 thousand Mt CO2e. Further work should integrate socioeconomic indicators reflecting additional local/regional stakeholders´ collaboration channels (cost-effective) to support the bioenergy transitions. 

  • 24.
    Carvalho, Ricardo
    et al.
    Danish Building Research Institute, Aalborg University, Copenhagen, Denmark; Centre for Environmental and Marine Studies, University of Aveiro, Campus Universitário de Santiago, Portugal.
    Vicente, Estela
    Tarelho, Luís
    Jensen, Ole Michael
    Wood stove combustion air retrofits: a low cost way to increase energy savings in dwellings2018In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 164, p. 140-152Article in journal (Refereed)
    Abstract [en]

    In Europe, wood-fired stoves remain as major renewable household heating and emission sources. This study focused on improving the performance of a wood stove (natural draft) traditionally used in Portugal by the adoption of alternative combustion air retrofits. Additionally, the performance of a new pellet stove (forced-air) was determined to investigate the highest achievable goal for solid-fuel stoves. In the wood stove, an outer chimney component was installed around the existing chimney to allow the vertical admission of outdoor air that was preheated before entering the combustion chamber. This measure increased the thermal efficiency of the wood stove from 62% to up to 79%. Another component was used to administrate secondary air to the wood stove reducing the carbon monoxide emissions by 39% to 2808 mg Nm−3. The two retrofits enhanced a more stable heat release from the wood stove, which reached a thermal efficiency 11% lower than that achieved by the pellet stove. This research suggests that retrofitting stoves with chimney components that allow the admission of combustion air can substantially increase energy savings in dwellings. Further efforts should focus on improving the interplay between the outdoor air and secondary air admission to achieve higher emission reductions at low-cost.

  • 25.
    Chavez-Rodriguez, Mauro F.
    et al.
    Energy Planning Program, COPPE/UFRJ - Universidade Federal do Rio de Janeiro, Cidade Universitaria, Centro de Tecnologia, Rio de Janeiro, RJ, Brazil.
    Carvajal, Pablo E.
    UCL Energy Institute, University College London, UK.
    Martinez Jaramillo, Juan E.
    Institución Universitaria Politécnico Grancolombiano, Bogotá, Colombia .
    Egüez, Alejandro
    Umeå University, Faculty of Social Sciences, Center for Environmental and Resource Economics (CERE).
    Gonzalez Mahecha, Rosa Esperanza
    Energy Planning Program, COPPE/UFRJ - Universidade Federal do Rio de Janeiro, Cidade Universitaria, Centro de Tecnologia, Rio de Janeiro, RJ, Brazil.
    Schaeffer, Roberto
    Energy Planning Program, COPPE/UFRJ - Universidade Federal do Rio de Janeiro, Cidade Universitaria, Centro de Tecnologia, Rio de Janeiro, RJ, Brazil.
    Szklo, Alexandre
    Energy Planning Program, COPPE/UFRJ - Universidade Federal do Rio de Janeiro, Cidade Universitaria, Centro de Tecnologia, Rio de Janeiro, RJ, Brazil.
    Lucena, Andre F. P.
    Energy Planning Program, COPPE/UFRJ - Universidade Federal do Rio de Janeiro, Cidade Universitaria, Centro de Tecnologia, Rio de Janeiro, RJ, Brazil.
    Arango Aramburo, Santiago
    Department of Computing and Decision Sciences, Universidad Nacional de Colombia, Medellín, Colombia .
    Fuel saving strategies in the Andes: long-term impacts for Peru, Colombia and Ecuador2018In: Energy Strategy Reviews, ISSN 2211-467X, E-ISSN 2211-4688, Vol. 20, p. 35-48Article in journal (Refereed)
    Abstract [en]

    Crude oil exports and imports play a crucial role in the trade balance of Peru, Colombia and Ecuador. These countries are looking into fossil fuel saving measures as a way to deal with increasing demands and decreasing oil production rates. However, studies about the long-term effects of these measures is lacking. Using a combination of energy simulation technics, 17 fuel saving strategies ranging from fuel switching to the investment in underground transport and hydropower capacity expansion were modelled and assessed to evaluate their long-term effect on fossil fuels demand reduction. Our results show that the full implementation of strategies can account for cumulative oil savings of over 550 million barrels of oil by 2030. Findings also point out that Ecuador and Colombia could face the transition from net oil-exporters to importers as soon as the end of the next decade.

  • 26.
    Cheng, Xiaogang
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. College of Telecommunications and Information Engineering, Nanjing University of Posts and Telecommunications, Nanjing, China; School of Electrical Engineering and Computer Science, Royal Institute of Technology, Stockholm, Sweden.
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. School of Environmental and Municipal Engineering, Xi’an University of Architecture and Technology, Xi'an, China.
    Liu, Guoqing
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    A total bounded variation approach to low visibility estimation on expressways2018In: Sensors, ISSN 1424-8220, E-ISSN 1424-8220, Vol. 18, no 2, article id 392Article in journal (Refereed)
    Abstract [en]

    Low visibility on expressways caused by heavy fog and haze is a main reason for traffic accidents. Real-time estimation of atmospheric visibility is an effective way to reduce traffic accident rates. With the development of computer technology, estimating atmospheric visibility via computer vision becomes a research focus. However, the estimation accuracy should be enhanced since fog and haze are complex and time-varying. In this paper, a total bounded variation (TBV) approach to estimate low visibility (less than 300 m) is introduced. Surveillance images of fog and haze are processed as blurred images (pseudo-blurred images), while the surveillance images at selected road points on sunny days are handled as clear images, when considering fog and haze as noise superimposed on the clear images. By combining image spectrum and TBV, the features of foggy and hazy images can be extracted. The extraction results are compared with features of images on sunny days. Firstly, the low visibility surveillance images can be filtered out according to spectrum features of foggy and hazy images. For foggy and hazy images with visibility less than 300 m, the high-frequency coefficient ratio of Fourier (discrete cosine) transform is less than 20%, while the low-frequency coefficient ratio is between 100% and 120%. Secondly, the relationship between TBV and real visibility is established based on machine learning and piecewise stationary time series analysis. The established piecewise function can be used for visibility estimation. Finally, the visibility estimation approach proposed is validated based on real surveillance video data. The validation results are compared with the results of image contrast model. Besides, the big video data are collected from the Tongqi expressway, Jiangsu, China. A total of 1,782,000 frames were used and the relative errors of the approach proposed are less than 10%.

  • 27.
    Cheng, Xiaogang
    et al.
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics. Nanjing Univ Posts & Telecommun, Coll Telecommun & Informat Engn, Nanjing, Jiangsu, Peoples R China; Royal Inst Technol, Sch Comp Sci & Commun, Stockholm, Sweden.
    Yang, Bin
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Liu, Guoqing
    Olofsson, Thomas
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Li, Haibo
    A variational approach to atmospheric visibility estimation in the weather of fog and haze2018In: Sustainable cities and society, ISSN 2210-6707, Vol. 39, p. 215-224Article in journal (Refereed)
    Abstract [en]

    Real-time atmospheric visibility estimation in foggy and hazy weather plays a crucial role in ensuring traffic safety. Overcoming the inherent drawbacks with traditional optical estimation methods, like limited sampling volume and high cost, vision-based approaches have received much more attention in recent research on atmospheric visibility estimation. Based on the classical Koschmieder's formula, atmospheric visibility estimation is carried out by extracting an inherent extinction coefficient. In this paper we present a variational framework to handle the nature of time-varying extinction coefficient and develop a novel algorithm of extracting the extinction coefficient through a piecewise functional fitting of observed luminance curves. The developed algorithm is validated and evaluated with a big database of road traffic video from Tongqi expressway (in China). The test results are very encouraging and show that the proposed algorithm could achieve an estimation error rate of 10%. More significantly, it is the first time that the effectiveness of Koschmieder's formula in atmospheric visibility estimation was validated with a big dataset, which contains more than two million luminance curves extracted from real-world traffic video surveillance data.

  • 28. Chilkoor, Govinda
    et al.
    Upadhyayula, Venkata Krishna Kumar
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Gadhamshetty, Venkataramana
    Koratkar, Nikhil
    Tysklind, Mats
    Umeå University, Faculty of Science and Technology, Department of Chemistry.
    Sustainability of renewable fuel infrastructure: a screening LCA case study of anticorrosive graphene oxide epoxy liners in steel tanks for the storage of biodiesel and its blends2017In: Environmental Science: Processes & Impacts, ISSN 2050-7887, E-ISSN 2050-7895, Vol. 19, no 2, p. 141-153Article in journal (Refereed)
    Abstract [en]

    Biodiesel is a widely used fuel that meets the renewable fuel standards developed under Energy Policy Act of 2005. However, biodiesel is known to pose a series of abiotic and biotic corrosion risks to storage tanks. A typical practice (incumbent system) used to protect the tanks from the risks include: (i) coat the interior surface of the tank with solvent free epoxy (SFE) liner, and (ii) add a biocide in the tank. We present a screening-level, life cycle assessment study to evaluate and compare the environmental performance of graphene-oxide (GO)-epoxy (GOE) liner with the incumbent system. TRACI is used as an impact assessment tool to model midpoint environmental impacts for the ten categories: global warming potential (GWP, kg CO2 eq.); acidification potential (AP, kg SO2 eq.); potential human health damage impacts due to carcinogens (HH-CP, CTUh) and non-carcinogens (HH-NCP, CTUh); potential respiratory effects (REP, kg PM2.5 eq); eutrophication potential (EP, kg N eq); ozone depletion potential (ODP kg CFC-11 eq); ecotoxicity potential (ETXP, CTUe); smog formation potential (SFP kg O3 eq); and fossil fuel depletion potential (FFDP MJ surplus). The equivalent functional unit of the LCA study is designed to protect the 30 m2 of the interior surface (unalloyed steel sheet) of a 10,000 liters biodiesel tank against abiotic and biotic corrosion during its service life of 20 years. Overall, this LCA study highlights an improved environmental performance for the GOE liner compared to the incumbent system; GOE-liner system showed: 91% lower ODP impacts; 59% smaller for REP; 62% smaller for AP; 67-69% smaller for GWP and HH-CP; 72-76% smaller for EP, SFP, and FFDP; and 81-83% smaller for ETXP and HH-NCP categories. The scenario analysis study reveals that these potential impacts change by less than 15% when the GOE liners are functionalized with silanized-GO nanosheets or GO-reinforced, polyvinyl carbazole to improve the antimicrobial properties. The results from uncertainty analysis indicate that the impacts for the incumbent system are more sensitive to changes in key modeling parameters compared to that for GOE liner system.

  • 29.
    Daniel, Petrovic
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Underlag till byte av värmekälla för skola i Adak.: Energi- och kostnadsbesparingar redovisas som kan göras för investering i ny värmekälla.2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport är skriven mot Malå kommun och syftar att ta fram en grund om vilken besparing som kan göras vid byte av energikälla för att sänka skolans energikostnader på ett miljövänligare sätt. Genom att göra en empirisk energibalans och beräkna den dimensionerande effekten ta fram underlag för rätt val av värmekälla. Den energikälla som idag betjänar skolans värmesystem är en gammal oljepanna som även förser en kallställd del av skolan med värme som inte används. Detta underhåll av den kallställda delen resulterar i att skolan idag lider av stora energiförluster. Diskussion har förts av Malås kommunstyrelse om att riva den kallställda delen. 

    En energikartläggning har gjorts av skolans fastighet för att utreda vilka alternativa uppvärmningslösningar som kan tillämpas. Avgränsning av uppvärmningslösningar har gjorts till värmepump och pelletspanna. För att kunna jämföra de olika uppvärmningslösningarna mot varandra har en livscykelkostnadsanalys (LCC) gjorts. Att bilda uppfattning om hur lång tid det skulle ta att betala av de olika investeringarna har även en pay off tid tagits fram.

    För en så verklighetstrogen bild som möjligt har problemet bemöts från tre olika angreppsvinklar. En överslagsberäkning av energifakturor inledde den första offensiven för att ta reda på nuvarande energibehov under dagens förutsättningar. Denna följdes av manuella energiberäkningarna av fastighetens olika byggnader. För att få stöd för de manuella beräkningarna gjordes energisimuleringar i programmet VIP-energy. För att sätta siffrorna i en kontext jämfördes dessa med statistiska nyckeltal hämtade från boverkets och energimyndighetens gemensamma rapport STIL 2. 

    Resultaten tyder på att värmepumpen är den mest lönsamma investeringen enligt livscykelkostnadsanalysen med en kalkylperiod på 20 år. Skolans teoretiska effektbehov som värmekällan bör dimensioneras efter är 77 kW. Den LCC de bägge värmekällorna visar i dagens penningvärde är:

    Värmepump: 2,1 Mkr

    Pelletspanna: 3,4 Mkr

     

    Med en pay off tid på 4,5 år jämfört med 18,5 år för pelletspanna visade sig värmepumpen även där som den lönsammare investeringen.

    Då den årlig uppvärmningen för skolan är 198 990 kWh kan 70-140 kkr sett till dagens penningvärde sparas per år beroende på uppvärmningslösning och kommunens beslut om fastighetens kallställda del.

    En hypotetisk analys av den årliga prisutvecklingen med hänsyn till inflationen för de olika energislagen olja, pellets och el har gjorts som antyder på att 50-80 % kostnadsbesparingspotential kan uppnås genom att byta från befintligt värmesystem med olja till pellets eller värmepump över kommande 20 års period.     

    Det radiatorsystem som idag används uppskattas kunna förse skolan med nödvändigt värmebehov utan att behöva om-dimensioneras vid installering av ny värmekälla. Därför föreslås att Malå kommun investerar i en värmepump som ersätter den befintlig oljepanna i Adaks förskola med hänsyn till effektivare slutanvändning av den inköpta energin.

  • 30.
    Danielski, Itai
    et al.
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för ekoteknik och hållbart byggande, Östersund.
    Nair, Gireesh
    The Department of Ecotechnology and Sustainable Building Engineering, Mid Sweden University, SE-831 25 Östersund, Sweden.
    Fröling, Morgan
    Mittuniversitetet, Fakulteten för naturvetenskap, teknik och medier, Avdelningen för ekoteknik och hållbart byggande, Östersund.
    Heated atrium in multi-storey apartment buildings: a design for better energy efficiency and social interactions2013In: Passivhus Norden 2013: Papers and Posters, Lågan , 2013, p. 76-87Conference paper (Other academic)
    Abstract [en]

    The shape factor of a building expresses the ratio between the building’s thermal envelope area and its volume, or alternatively to its useful floor area. Buildings with lower shape factors will have lower heat losses through the thermal envelope and lower specific final energy demand. The shape factor of building could be reduced by a compact building shape design, and by increasing the volume of the building. However, the requirement for indoor natural light put a limit on the size of the building and therefore may limit the value of the shape factor. One possible solution to address this aspect is designing building with a heated atrium.

    An atrium is a large enclosed space within a building, and may have a glazed roof. In a multi-story apartment building an atrium has the potential to increase the social interaction between the residents and, with the right design, at the same time reduce the heating demand of the building due to lower building shape factor. However, the use of atrium in residential buildings in Nordic countries has not yet gained popularity.

    In this paper the impact of the heated atrium building with cylindrical shape design on the specific final energy is investigated by comparing such building design to conventional design buildings with similar floor area. The Nydalahuset project, in city Umeå in the north of Sweden, which is a multistory residential building with a heated atrium, is used as a case study to investigate the affect of the atrium on the social interaction among the building occupants.

    The results show that heated atrium building with cylindrical shape design is a better energy efficient design than the conventional buildings. Such buildings in cold climate could help to reduce the heat losses through the thermal envelope and facilitate to achieve the passive house criteria. Moreover, the Nydalahuset project suggests that the atrium design could improve the social interaction of occupants in residential buildings.

  • 31. Danielski, Itai
    et al.
    Nair, Gireesh
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Joelsson, Anna
    Fröling, Morgan
    Heated atrium in multi-storey apartment buildings, a design with potential to enhance energy efficiency and to facilitate social interactions2016In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 106, p. 352-364Article in journal (Refereed)
    Abstract [en]

    The design concept of conditioned atria gains increasing popularity in commercial and service buildings all over the world, but is still not a common building design in the residential sector. This study investigates the potential of such design in residential buildings in Nordic climates as means to enhance both energy efficiency as well as social interaction among residents. Energy modelling was used to compare energy efficiency among designs of residential buildings with and without atrium and to identify important design parameters. Social interaction was analysed, based on a survey evaluating the perception of residents living in an existing multi-storey apartment building designed with a heated atrium in the north of Sweden. The results show that heated atrium in Nordic climates have a potential to reduce the total final energy demand while at the same time increase the conditioned space of the building. To positively impact energy efficiency, the atrium should fulfil three requirements: (i) it should be designed to reduce the shape factor for the whole building; (ii) it should have the minimum glazed area that comply with the building requirements concerning natural light and visual comfort; and (iii) adjustable solar shading should be installed in the atrium’s façades to avoid unwanted overheating. The survey results indicate that the additional space created by the atrium has a potential to facilitate and promote social interaction among residents and to increases a sense of neighbourliness and belongingness, which are often discussed as important parameters in relation to social sustainability.

  • 32. Das, Sujit
    et al.
    Graziano, Diane
    Upadhyayula, Venkata K. K.
    Masanet, Eric
    Riddle, Matthew
    Cresko, Joe
    Umeå University, Faculty of Science and Technology. U.S. Department of Energy, Washington, DC 20585, USA.
    Vehicle lightweighting energy use impacts in U.S. light-duty vehicle fleet2016In: Sustainable Materials and Technologies, ISSN 2214-9937, Vol. 8, p. 5-13Article in journal (Refereed)
    Abstract [en]

    In this article, we estimate the potential energy benefits of lightweighting the light-duty vehicle fleet from both vehicle manufacturing and use perspectives using plausible lightweight vehicle designs involving several alternative lightweight materials, low- and high-end estimates of vehicle manufacturing energy, conventional and alternative powertrains, and two different market penetration scenarios for alternative powertrain light-duty vehicles at the fleet level. Cumulative life cycle energy savings (through 2050) across the nine material scenarios based on the conventional powertrain in the U.S. vehicle fleet range from - 29 to 94 billion GJ, with the greatest savings achieved by multi-material vehicles that select different lightweight materials to meet specific design purposes. Lightweighting alternative-powertrain vehicles could produce significant energy savings in the U.S. vehicle fleet, although their improved powertrain efficiencies lessen the energy savings opportunities for lightweighting. A maximum level of cumulative energy savings of lightweighting the U.S. light-duty vehicle through 2050 is estimated to be 66.1billion GJ under the conventional-vehicle dominated business-as-usual penetration scenario. (C) 2016 Elsevier B.V. All rights reserved.

  • 33. Eggermont, Hilde
    et al.
    Balian, Estelle
    Azevedo, Jose Manuel N.
    Beumer, Victor
    Brodin, Tomas
    Umeå University, Faculty of Science and Technology, Department of Ecology and Environmental Sciences.
    Claudet, Joachim
    Fady, Bruno
    Grube, Martin
    Keune, Hans
    Lamarque, Penelope
    Reuter, Katrin
    Smith, Matt
    van Ham, Chantal
    Weisser, Wolfgang W.
    Le Roux, Xavier
    Nature-based Solutions: New Influence for Environmental Management and Research in Europe2015In: GAIA, ISSN 0940-5550, Vol. 24, no 4, p. 243-248Article in journal (Refereed)
    Abstract [en]

    Greening roofs or walls to cool down city areas during summer, to capture storm water, to abate pollution, and to increase human well-being while enhancing biodiversity: nature-based solutions (NBS) refer to the sustainable management and use of nature for tackling societal challenges. Building on and complementing traditional biodiversity conservation and management strategies, NBS integrate science, policy, and practice and create biodiversity benefits in terms of diverse, well-managed ecosystems.

  • 34.
    Ekerholm, Helena
    Umeå University, Faculty of Arts, Department of historical, philosophical and religious studies.
    Cultural meanings of wood gas as automobile fuel in Sweden 1930-19452012In: Past and present energy societies: How energy connects politics, technologies and cultures / [ed] Nina Möllers & Karin Zachmann, Bielefeld: Transcript Verlag, 2012, p. 223-247Chapter in book (Other academic)
  • 35.
    Eklund, Victor
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Utökad nytta av befintligt energilager2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The electrical grid is facing a modernization due to installations of intermittent energy production from wind and solar energy. Energy storage fulfills an important role in this modernization, with potential to store overproduced electricity and use it at a later time. By balancing electricity production and consumption with energy storage, it can provide the grid with stability, increased flexibility and reduce the grid load. An energy storage also makes it possible to keep down the dimensioning at exposed points in the grid, as in connections with high power fast charging stations.

    In the electrical grid of Umea Energy, there is a battery storage of 118 kWh, connected to a fast charging station for electric buses. The high power required by the charging station risked affecting nearby customers, therefore a solution with a battery storage was installed to reduce the impact. With this type of solution, a proportion of power can be retrieved from the grid and the battery storage simultaneously to the fast charging station, which contributes to the power output being smoothed out. However, solutions with battery storage are currently very expensive. To be able to justify an investment of this type of solutions, it is of interest to investigate whether it is possible to increase the utility of a battery storage in order to make the solution more profitable. The purpose of this paper is thus to examine how Umea Energy can increase the utility of a battery storage connected to a charging station and when such a solution may become an economic alternative.

    In this paper, simulation models have been developed in the software MATLAB to investigate whether the battery storage can be used to: 1) reduce power peaks in the neighboring residential area, where the results show that it is possible to reduce a small amount of power in the residential area but that the reduction is limited by how frequent the electric buses charges. 2) Move the load in the grid by letting the battery storage discharge during peak load hours and then recharge it at a later time. The result shows that it may be achievable for a certain time but it could affect the lifetime of the battery storage due to higher depth of discharge (DoD) and 3) Reduce the power during charging of the battery storage. The result indicates that the power can be reduced down to a quarter until affecting the charging schedule of the battery.

    The economic calculations that were carried out compared the profitability of installing a battery storage of 118 kWh to grid investments of 1) two transformers of size 800 kVA each or 2) new grid station incl. two 800 kVA transformers. The result show that there is no economic benefit for Umea Energy to install a battery storage of the investigated type of lithium titanate (LTO) or lithium iron phosphate (LFP) with prices based on 2016 but that it may become profitable with estimated prices from 2030.

    The conclusion that has been drawn from the simulations is that with regard of expanding the utility of a battery storage, there is only a small gain in using the battery storage to reduce power peaks. However, a lower maximum power required from the grid, can advantageously be achieved with a battery storage. In addition, the grid power can be reduced by moving the load during charging of the battery storage between the high peak hours or by reducing the power during the charging of the battery storage. With current battery prices, a battery storage is not considered a profitable investment, and therefore should only be installed to meet specific needs that would otherwise require expensive grid investments. However, the price trend for battery storage looks promising and with prices from forecasts of year 2030 it may become a competitive alternative.

  • 36.
    Emil, Rönnmark
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Energikartläggning av Kopparhuset i Skellefteå2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 37.
    Engman Reed, Martina
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Plan for evaluation of Austin Energy Green Building’s Multifamily Rating Program2014Independent thesis Advanced level (degree of Master (Two Years)), 300 HE creditsStudent thesis
    Abstract [en]

    Austin Energy Green Building (AEGB) started their multifamily rating program in 1999. It is a green building program where participants can receive different ratings, 1-5 stars, depending on how many requirements the building fulfills. AEGB wants to evaluate the projected energy and demand savings from the multifamily program to be able to report to Austin Energy at the end of the fiscal year.

    Buildings going through the multifamily rating program can either use a prescriptive approach or a performance approach. For the prescriptive approach the savings are evaluated with the help of a deemed savings value. For the performance approach the participant needs to turn in an energy model of the proposed buildings with modeled projected energy and demand savings.

    The purpose of this degree project was to develop a plan for evaluation of the projected savings from the multifamily rating program.  AEGB will need to be able to compare the projected energy and demand savings with the actual energy and demand savings from the buildings that have gone through the program. Focus has been on finding a suitable evaluation approach, based on the available data. Criteria for inclusion were determined. Evaluation of all buildings is not be possible and therefore a sample size needed to be determined for the population. The projected energy savings data was analyzed. A way to account for apartments without full year use data was studied as well as common criteria for uncertainty analysis.

    It was suggested that one year of full energy use data was enough as criterion for buildings to be a part of the population to be evaluated, which gave a population size of 29 buildings.  of the buildings received a 1-3 star rating and they account for about  or  of the projected energy savings. If a simple random sample is used with a confidence level of  and  relative precision the sample will be 21 buildings. If the relative precision is changed to  the sample will contain 11 buildings. Another option is to use stratified random sample, and sample sizes were calculated by star rating and size of the buildings. A number of different ways of accounting for vacant units were found however the latest vacancy rate for multifamily buildings in Austin was . This corresponds to about  in lost projected energy savings for the buildings that have gone through AEGB’s multifamily program. Lastly, post occupancy evaluation (POE) will be recommended for this evaluation effort of AEGB’s multifamily program.

  • 38.
    Eriksson, Henrik
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Tillvaratagande av förlustvärme från frekvensomformarstationer2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    För effektmatning av den elektrifierade järnvägen krävs att spänningens frekvens omformas från kraftnätets frekvens på 50 Hz till 16,7 Hz. Detta sker i dag med två olika metoder. En metod där frekvensen omformas på mekanisk väg då en motor på gemensam axel driver en generator som genererar elkraft av rätt frekvens, detta kallas för en roterande frekvensomformare. Den andra metoden ändrar spänningens frekvens med hjälp av kraftelektronik, detta kallas för en statisk frekvensomformare. Gemensamt för båda dessa metoder är att de har värmeförluster. För de roterande omformaraggregaten så är förlustvärmen till stor del luftburen medan de statiska frekvensomformarna har både vätske- och luftkylning. I många fall ser det i dagsläget ut så att förlusterna kyls bort mot omgivningen.

    Syftet med detta arbete är att bestämma huruvida dessa värmeförluster kan nyttjas för uppvärmning av stationsbyggnaderna där omformaraggregaten finns på ett lönsamt vis.

    I arbetet har två frekvensomformarstationer undersökts. En station med enbart roterande frekvensomformare i Gällivare samt en station med enbart statiska frekvensomformare i Boden. Båda omformarstationerna har idag energisystem för uppvärmning baserade på direktverkande el.

    I simuleringsmodeller och mätningar har de båda omformarstationernas energibehov för uppvärmning fastställts. För Gällivare omformarstation rör det sig om en specifik energiförbrukning för uppvärmning motsvarande ca 300 kWh/m2. För Bodens omformarstation är den sammantagna specifika energianvändningen 204 kWh/m2.

    Genom ytterligare mätningar har delar av frekvensomformaraggregatens effektförluster fastställts och analyserats med hänsyn till storlek och tidsvariationer. Rapporten fastslår att förlustvärmen från luftkylningen av de roterande omformarna räcker för att täcka stationens uppvärmningsbehov. Rapporten fastslår även att tomgångsförlusterna från ett omformaraggregat räcker för att förse omformarstationen i Boden med tillräcklig värmeenergi för uppvärmning. De båda omformarstationernas förlusteffekter uppvisade även en regelbundenhet i effektflödet vilket möjliggör för en värmeåtervinningslösning utan behov av ackumulator.

    För Gällivares omformarstation har ett utformat förslag på en teknisk lösning för uppvärmning av omformarstationen med förlustvärme från frekvensomformaraggregaten presenterats. Detta består av ett projekterat och dimensionerat överluftssystem för uppvärmning av byggnaden med den uppvärmda luften från frekvensomformaraggregatens kylsystem. Luftflödet för att möta det simulerade effektbehovet för uppvärmning uppgår i ca 9,5 l/(s ∙m2), ett flöde som kan orsaka problem med luftdrag och ljudalstring som gör arbetsmiljön dålig. Då omformarstationen i normala fall är obemannad föreslogs en strömbrytare som inaktiverar överluftssystemet vid besök på omformarstationen av underhållspersonal. En ekonomisk sammanställning baserad på LCC (Life cycle cost) har fastställt att en investering kan vara lönsam inom 5 år. För Bodens omformarstation har ingen teknisk lösning presenterats.

  • 39.
    Fagerström, Jonathan
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Fine particle emissions and slag formation in fixed-bed biomass combustion: aspects of fuel engineering2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    There is a consensus worldwide that the share of renewable energy sources should be increased to mitigate climate change. The strive to increase the renewable energy fraction can partly be met by an increased utilization of different biomass feedstocks. Many of the "new" feedstocks puts stress on certain challenges such as air pollution emissions and operation stability of the combustion process. The overall objective was to investigate, evaluate, and explain the effects of fuel design and combustion control - fuel engineering - as primary measures for control of slag formation, deposit formation, and fine particle emissions during biomass combustion in small and medium scale fixed-bed appliances. The work in this thesis can be outlined as having two main focus areas, one more applied regarding fuel engineering measures and one more fundamental regarding the time-resolved release of ash forming elements, with particular focus on potassium.

    The overall conclusion related to the abatement of particle emissions and slag formation, is that the release of fine particle and deposit forming matter can be controlled simultaneously as the slag formation during fixed-bed biomass combustion. The methodology is in this perspective denoted “fuel engineering” and is based on a combined approach including both fuel design and process control measures. The studies on time-resolved potassium release showed that a Macro-TG reactor with single pellet experiments was a valuable tool for studying ash transformation along the fuel conversion. The combination of dedicated release determinations based on accurate mass balance considerations and ICP analysis, with phase composition characterization by XRD, is important for the understanding of potassium release in general and time-resolved data in particular. For wood, the results presented in this work supports the potassium release mechanism from "char-K" but questions the previously suggested release mechanism from decomposition of K-carbonates. For straw, the present data support the idea that the major part of the potassium release is attributed to volatilization of KCl. To further explore the detailed mechanisms, the novel approach developed and applied in this work should be complemented with other experimental and analytical techniques.

    The research in this thesis has explored some of the challenges related to the combined phenomena of fuel conversion and ash transformation during thermochemical conversion of biomass, and has contributed with novel methods and approaches that have gained new knowledge to be used for the development of more effective bioenergy systems.

  • 40.
    Falk, Joel
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Particle and feeding characteristics of biomass powders2013Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Milling of biomass is a necessary key step in suspension gasification or powder combustion. Milled biomass powders are often cohesive, have low bulk density and poor flowability leading to costly problems in fuel handling. Two different milling methods with four different biomass powders have been performed to correlate between particle and feeding properties. Charcoal, Torrefied Norway spruce, Norway spruce and reed canary grass where milled (knife mill or hammer mill) with a screen size of 1 mm. The resulting powders where analyzed using both mechanical sieving and optical sieveless particle size analysis. After bulk and tapped density tests, the powders were fed through a twin screw feeder onto an analytic scale that logged the weight data on a pc. Two tests were made, one with constant screw speed and the other using a built-in function called loss in weight feeding. The hammer mill produced more homogenous powders with more fines than the knife mill. They also had lower bulk and tapped density. The feeding tests were inconclusive as two materials where easier fed when hammer milled and two when knife milled. Hammer milled materials had better initial feeding stability. Another interesting observation was that two of the materials showed good agreement with a feeding rate that could be predicted if assuming tapped density while the other two behaved more similar to what would be the case for bulk density. 

  • 41. Figuero, Andres
    et al.
    Rodriguez, Alvaro
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sande, Jose
    Pena, Enrique
    Rabunal, Juan R.
    Dynamical study of a moored vessel using computer vision2018In: Journal of Marine Science and Technology, ISSN 0948-4280, E-ISSN 1437-8213, Vol. 26, no 2, p. 240-250Article in journal (Refereed)
    Abstract [en]

    Wind and wave effects have a major impact on the design of mooring and anchoring systems, whose purpose is to prevent the movement of the cargo and the moored ship while optimizing the operations which have to take place in port. The dynamic behavior of a ship moored in waves has been mathematically described and interactions between ships and environmental loads have been commonly tested for different docks and mooring systems in scale models. However, the behavior of real ships in true mooring conditions has not been properly addressed in scientific literature. This paper proposes a novel computer vision technique to monitor moored ships. This approach uses the correlation of visual features in the images of the ship to estimate its movements along time. The proposed technique has been validated in laboratory conditions and applied in a real scenario to study the behavior of the ship Urania Mella in the Outer Port of A Coruna (Spain), in Punta Langosteira, obtaining very promising results.

  • 42. Figuero, Andrés
    et al.
    Rodriguez, Alvaro
    Umeå University, Faculty of Science and Technology, Department of Physics.
    Sande, Jose
    Peña, Enrique
    Rabuñal, Juan R.
    Field measurements of angular motions of a vessel at berth: Inertial device application2018In: Control Engineering and Applied Informatics, ISSN 1454-8658, Vol. 20, no 3, p. 79-88Article in journal (Refereed)
    Abstract [en]

    The study and characterization of the oscillations of a moored vessel has a major importance in port operational efficiency, not only in the design of mooring and anchoring systems, but also in order to prevent the movement of the cargo, minimize ship and dock damage and optimizing the operations which have to take place while the ship is moored.The dynamic behavior of a vessel moored in waves has been mathematically described and interactions between ships and environmental loads such as waves, wind, currents and ice are commonly tested for different docks and mooring systems in scale models. However, field data studies of the behavior moored ships have not been properly addressed so far.This paper proposes a novel application of Inertial Measurement Units to estimate the angular movements (roll, pitch and yaw) of a moored vessel. The proposed technique has been validated in laboratory conditions and the behavior of the ship Urania Mella in the Outer Port of Punta Langosteira (A Coruña, Spain), has been analyzed, obtaining very promising results.

  • 43.
    Fossum, Heidi
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Coordinated freight logistics in existing city districts- Evaluation of methods for calculating energy and environmental effects2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Norra Djurgårdsstaden is the largest ongoing construction project in Sweden and is planned to be completed in 2030. The city district is situated in north-eastern Stockholm, in a former industrial area where approximately 12 000 new homes and 35 000 workplaces are planned. The city district focuses strongly on reducing energy consumption and the negative impacts on the environment. One idea for realizing this goal is to implement coordinated freight logistics. This can be accomplished by building a consolidation centre where goods from different logistics companies and freight carriers can be loaded together on the same delivery vehicles and then be delivered in the same area in Norra Djurgårdsstaden.

     

    The purpose of this master thesis is to evaluate five earlier evaluation reports on consolidation centres. Based on these evaluation reports and other relevant literature, it is recommended how a coordinated freight logistic project should be organized in Norra Djurgårdsstaden and how the impact on the environment and energy consumption should be calculated. The evaluation reports are from the logistic centre in the Old Town of Stockholm, the pilot project Samlic in Linköping, the urban consolidation centre in Norwich, the micro-consolidation centre in London and several urban logistic practices in Utrecht. A thorough comparative analysis of the five different evaluation reports has looked at the initiators and the stakeholders, the delivery situation before and after the implementation of the consolidation centre as well as done a deeper evaluation analysis of all the evaluation reports. The comparative analysis showed that the consolidation centres have had a positive effect on decreasing the number of delivery vehicles in the city district and thereby reducing the emissions and the energy consumption from the delivery vehicles.

     

    Based on the comparative analysis and other literature it is suggested that the initiative to build a consolidation centre in Norra Djurgårdsstaden has to come from the City of Stockholm. The stakeholders should be the City of Stockholm, logistics companies, freight companies, the different businesses in the area and the Ports of Stockholm. To encourage even more businesses to have deliveries from the consolidation centre and get more environmentally friendly delivery vehicles in the city district it might be necessary to use several management control instruments. Examples of control instruments are environmental zones, time windows and implement different restrictions on the delivery vehicles. It is essential to gather information about the delivery vehicles in the city district to estimate emissions and the energy consumption. The collection of data from the delivery vehicles can be gathered from consignment notes, driver notes, invoice data or statistics of the number of vehicles that have delivered goods in the city centre from freight and logistics companies. Then the delivery vehicles impact on energy consumption and the environment can be estimated with the computer tool Network of transports and environment (NTM-method).

     

  • 44.
    Gandla, Madhavi Latha
    et al.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. KBC Chemical-Biological Centre, Umeå University.
    Martin, Carlos
    Umeå University, Faculty of Science and Technology, Department of Chemistry. KBC Chemical-Biological Centre, Umeå University.
    Jönsson, Leif J.
    Umeå University, Faculty of Science and Technology, Department of Chemistry. KBC Chemical-Biological Centre, Umeå University.
    Analytical Enzymatic Saccharification of Lignocellulosic Biomass for Conversion to Biofuels and Bio-Based Chemicals2018In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 11, no 11, article id 2936Article, review/survey (Refereed)
    Abstract [en]

    Lignocellulosic feedstocks are an important resource for biorefining of renewables to bio-based fuels, chemicals, and materials. Relevant feedstocks include energy crops, residues from agriculture and forestry, and agro-industrial and forest-industrial residues. The feedstocks differ with respect to their recalcitrance to bioconversion through pretreatment and enzymatic saccharification, which will produce sugars that can be further converted to advanced biofuels and other products through microbial fermentation processes. In analytical enzymatic saccharification, the susceptibility of lignocellulosic samples to pretreatment and enzymatic saccharification is assessed in analytical scale using high-throughput or semi-automated techniques. This type of analysis is particularly relevant for screening of large collections of natural or transgenic varieties of plants that are dedicated to production of biofuels or other bio-based chemicals. In combination with studies of plant physiology and cell wall chemistry, analytical enzymatic saccharification can provide information about the fundamental reasons behind lignocellulose recalcitrance as well as about the potential of collections of plants or different fractions of plants for industrial biorefining. This review is focused on techniques used by researchers for screening the susceptibility of plants to pretreatment and enzymatic saccharification, and advantages and disadvantages that are associated with different approaches.

  • 45. Garcia-Gasulla, Dario
    et al.
    Poch, Mane
    Nieves, Juan Carlos
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Cortes, Ulises
    Turon, Claudia
    A logic-based environmental decision support system for the management of horizontal subsurface constructed wetlands2012In: Ecological Engineering: The Journal of Ecotechnology, ISSN 0925-8574, E-ISSN 1872-6992, Vol. 47, p. 44-55Article in journal (Refereed)
    Abstract [en]

    The use of Horizontal Subsurface Constructed Wetlands (HSCWs) for treating wastewaters in small communities has increased in the last years due to HSCW's ecological singularities. Unfortunately, the same singularities that differentiate HSCWs complicate any attempt to develop models and produce generic decision-support systems for them. Classical mathematical and statistical approaches used in other Wastewater Treatment Plants do not properly fit the particularities of HSCW and provide little insight in the domain of HSCW. We introduce a novel approach based on logic-based declarative specifications, i.e. non-monotonic causal logic, to capture explicit and implicit knowledge about HSCWs. By expressing all the relevant aspects of a HSCW in a declarative way, we produce a logic-based model which captures features that other approaches fail to formalize. At the end, we produce a complete decision-support system based on that model and test it against a set of realistic scenarios validated by experts. We discuss in which aspects this approach performs better than the most commonly proposed solutions in the bibliography and why it does so. (C) 2012 Elsevier B.V. All rights reserved.

  • 46. Garme, K.
    et al.
    Burstrom, Lage
    Umeå University, Faculty of Medicine, Department of Public Health and Clinical Medicine.
    Kuttenkeuler, J.
    Measures of vibration exposure for a high-speed craft crew2011In: Journal of Engineering for the Maritime Environment (Part M), ISSN 1475-0902, E-ISSN 2041-3084, Vol. 225, no 4, p. 338-349Article in journal (Refereed)
    Abstract [en]

    The paper compares measurement-based measures for human vibration exposure. Data were collected during sea trials on a 10 m, 50 kn coastguard craft equipped with a three-axial accelerometer at the coxswain seat and with vertically mounted gauges measuring the acceleration of the cockpit floor. The ISO 2631-1:1997 measures of vibration (namely the root-mean-square (r.m.s.) value of the whole-body vibration (determined from the frequency-weighted acceleration signal), the maximum transient vibration value (MTVV), and the vibration dose value), the ISO 2631-5:2004 measure (namely the daily equivalent static compression dose Sed), and also statistically based measures to evaluate the acceleration magnitude are compared and discussed with respect to their ability to identify the mitigating effect of the suspension seat and how the different measures rank the severity of the high-speed craft (HSC) ride. The paper concludes that the r.m.s. value and the MTVV are unsuitable for evaluation of the conditions aboard while the other investigated measures show potential in this respect. Further the approach of ISO 2631-5:2004 taking both the short-term and the long-term perspectives on the human exposure to vibration is concluded to be the most mature method well suited to evaluation of HSC conditions.

  • 47.
    Garrison, Thomas G.
    et al.
    Umeå University, Faculty of Arts, Humlab.
    Chapman, Bruce
    Houston, Stephen
    Roman, Edwin
    Garrido Lopez, Jose Luis
    Discovering ancient Maya settlements using airborne radar elevation data2011In: Journal of Archaeological Science, ISSN 0305-4403, E-ISSN 1095-9238, Vol. 38, no 7, p. 1655-1662Article in journal (Refereed)
    Abstract [en]

    This report presents the results of using NASA/JPL airborne synthetic aperture radar data (AIRSAR) to detect ancient Maya settlements beneath jungle canopy in Guatemala. AIRSAR stands out from previous applications of radar remote sensing in the Maya lowlands because of its canopy-penetrating capabilities. The authors offer an overview of the AIRSAR technology, followed by a case study in which the AIRSAR data receive testing in the field. Reconnaissance in the region around the Maya site of El Zotz led to the discovery of two new sites, including the medium-sized settlement of La Avispa. AIRSAR also aided archaeologists in detecting zones of residential settlement around the site core of El Zotz. This research will serve as a guide for future applications of radar remote sensing in Maya archaeology. (C) 2011 Elsevier Ltd. All rights reserved.

  • 48.
    Gustavsson, Leif
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Mahapatra, Krushna
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Nair, Gireesh
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Implementering av energieffektiviseringsåtgärder i befintlig bebyggelse: Report prepared for the Swedish Energy Agency2010Report (Other (popular science, discussion, etc.))
    Abstract [en]

    There is great potential to improve energy efficiency in existing Swedish residential buildings. However, the successful implementation of efficiency measures depends on economical and technical factors, as well as on the attitudes and perceptions of the relevant actors. A better understanding of their attitudes and perceptions may influence the design of suitable policy measures that increase the adoption of energy efficiency measures. In this context, we conducted mail-in surveys completed by owners of detached houses, chairmen of co-operative housing associations (bostadsrättsförening) and municipality energy advisers in Sweden. We also interviewed window sellers/installers in Jämtland.

    Results show that it was important for the majority of homeowners to reduce their household energy use, with most undertaking no-cost measures (e.g., switching off lights). However, 70–90% of the responding homeowners had no intention of adopting building envelope measures over the next 10 years. The main reason for non-adoption was that homeowners were satisfied with the physical condition and thermal performance of their existing building envelope components. Homeowners who thought their energy cost was high were more likely to adopt an investment measure compared to those who thought their energy cost was low. Investment costs and annual energy cost savings were the most important factors in adoption of energy efficient building envelope measures. Therefore, economic incentives may induce homeowners to adopt energy efficiency investment measures. However, a large percentage (64%) of homeowners was unaware of the existence of government support for reducing household energy use. Information campaigns announcing the availability of economic incentives and the cost advantages of energy efficiency measures may be helpful in the adoption decision.

    Homeowners‘ considered interpersonal sources, builders, installers and energy advisers as important sources of information for their adoption of energy efficiency measures. Though a large percentage of respondents considered energy advisers as an important source of information, only 14% of homeowners had contacted an energy adviser in the past. Our findings suggest that the energy advice service is important for homeowners, but more efforts are needed to increase homeowners‘ awareness of and satisfaction with such services. The majority of municipal energy advisers were of the opinion that more training in technical aspects of energy issues and increased financial support could improve their performance.

    Installers and material suppliers are important actors in homeowners‘ adoption of energy efficiency measures. For example, approximately 53% of responding homeowners to a survey in Jämtland/Västernorrland stated that the window seller/installer from whom they had bought windows had recommended a particular type of window, and 97% had installed the windows that were recommended. The window sellers/installers in Jämtland prefer a window that is ―reasonably‖ energy efficient. They believe that windows with a U-value of 1.2 W/m2K are good and there is no reason to further improve the energy efficiency. The majority did not recommend windows with U-value <1.2 W/m2K. They were concerned about the condensation issues and high prices of such windows. This may influence the diffusion of very energy efficient windows in Swedish detached houses.

    About 80-95% of chairmen in co-operative housing associations who responded to our survey had no intention of adopting building envelope measures over the next 10 years. They were satisfied with the existing building envelope components, which may be one of the reasons for this lack of intention. As in the case of owners of detached houses, economic factors, like annual energy cost savings and investment costs, guide the implementation of energy efficiency investment measures in co-operative housing associations. However, about 66% of the responding chairmen did not consider financial constraint as a barrier to implementing investment intensive energy efficiency measures. For 54% of the respondents limited in-house competency to evaluate the benefits of energy efficiency measures was the main barrier.

    The majority of owners of detached houses (80%) and chairmen of co-operative housing associations (70%) perceived that economic policy instruments, such as investment subsidies and tax deductions, would encourage them to implement energy efficiency measures. Other policy instruments, especially information instruments, were perceived as less effective. Among various information policies, increasing the frequency of meter reading received the highest approval with 38% of homeowners, whereas approximately 41% of housing association chairmen thought that individual metering of heating and hot water use could be effective. Approximately 30% of homeowners and housing association chairmen thought that energy declaration was effective.

  • 49.
    Gustavsson, Leif
    et al.
    Mittuniversitetet, Östersund.
    Mahapatra, Krushna
    Mittuniversitetet, Östersund.
    Nair, Gireesh
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Implementing energy efficiency measures in existing Swedish building stock2008In: World Sustainable Energy Days, 2008Conference paper (Refereed)
    Abstract [en]

    There is a large potential for improving energy efficiency in the existing Swedish building stock. However, how successful the implementation of the efficiency measures will be, depends on economical and technical factors as well as on the attitudes and perceptions of the relevant actors. In this paper we use Rogers’ diffusion of innovation theory to analyze various factors affecting implementation of energy efficiency measures in the Swedish detached houses and apartment buildings. Results of recent Swedish household surveys concerning adoption of heating systems showed that majority of the respondents were satisfied with their heating systems and did not intend to install a new one. Economic aspects and functional reliability were important factors in the choice of heating systems, while installers/vendors were the most important sources of information on heating system. We discuss upcoming empirical studies on implementation of other energy efficiency measures, e.g. energy efficient windows and additional insulation, including that of heating systems, in detached houses and apartment buildings.

  • 50.
    Görtz, Steffen
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Battery energy storage for intermittent renewable electricity production: A review and demonstration of energy storage applications permitting higher penetration of renewables2015Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Driven by resource politics and climate change, the transition from conventional fossil fuel based and centralized energy generation to distributed renewables is increasing rapidly. Wind and solar power generation offer carbon dioxide neutral electricity but also present some integration difficulties for energy system operators and planners due to intermittent power output. A promising way of dealing with the intermittency from renewables is energy storage.

    The method of storing energy in the electricity grid, especially by the means of electrochemical storage, has gained a lot of attention over the last years in the energy sector. While most utilities and energy market stakeholders have the basic understanding of energy storage, a more profound knowledge of grid storage applications is often lacking. This thesis aims to highlight and explain possible energy storage applications with focus on renewables integration.

    Battery energy storage can allow higher amounts of renewable electricity generation to be integrated by smoothening power output, time shifting generated energy to follow demand and increase hosting capacities through peak shaving. Power quality related issues due to intermittency can be mitigated by controlling the storage’s charging patterns to respond to grid variables. For optimal utilization and maximum storage value, several applications should be within the operational repertoire of the storage unit. Other applications including arbitrage, grid investment deferral and load following are discussed.

    Several battery technologies which have been developed and tested for such applications including lead acid, sodium sulfate and lithium-ion are presented. The most promising battery energy storage technology is lithium-ion with exceptional storage characteristics and most importantly a favorable near term price development.

    Two case studies on two of Umeå Energy’s low voltage networks simulating high penetrations of solar generation have been carried out to demonstrate mitigation of overvoltage and peak shaving with battery energy storage systems. The simulations show that energy storage systems can successfully be used to aid the integration of renewables in the electricity grid. Present capital costs are still too high for energy storage to be feasible but falling pricing and a developing market is foreseen to lower the hurdles. 

    The main obstacle for energy storage at grid scale besides high capital costs are, in principle, non-existing legal frameworks regulating the ownership of energy storage systems and system technology standardization. Further discussions on the matter in combination with testing and pilot projects are needed to gain national and international experience with battery energy storage for the successful high share integration of renewables.

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