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  • 1.
    Aftab, Mohammad Adnan
    Halmstad University, School of Business, Engineering and Science.
    Biofuel, An alternative source for jet fuel in Aviation2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The transport industry is one of the fastest growing industries with the sector playing a significant role in negative impact on global warming and pollution through the emission of greenhouse gases. Aviation in particular, has enjoyed growth especially in the few decades. New airlines and aircraft manufacturers are coming up with different innovations and technologies to ensure they make the best possible environmentally friendly aircraft. The new main area of focus has been on how to come up with fuel that will reduce the greenhouse gas-emissions. The stakeholders in the same effort include developed nations like the United States, United Kingdom, Russia, France, Germany, and Canada among others. Energy providers as well as jet fuel suppliers are also making efforts to conserve the environment. The purpose of this thesis is to explore the area of biofuel in aviation by looking into various stakeholders involved in the efforts of the transition from fossil fuel to biofuel. The conclusion of this thesis is that biofuels are viable options in the aviation industries since there have been positive results in the tests made. 

  • 2.
    Alex, Ansu
    Halmstad University, School of Business, Engineering and Science.
    Comparison study of various current and potential liquid biofuels in road freight transport: Application on a case study on Transport Centralen in Halmstad2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The role of liquid biofuels in transportation to minimize the effects of climate change is  evident and has led to a number of studies on finding effective solutions to replace fossil fuels. Liquid biofuels are especially important for heavy duty transports as the effective ‘green’ alternatives are not as many compared to light duty vehicles; for which for e.g. electrification is an option. This thesis presents a comparison study of 8 liquid biofuels with a total of 13 different fuel pathways for use in road freight transports; both current and potential future fuels are assessed in terms of their environmental effects, fuel properties and compatibility with the heavy duty vehicle engines (see Table 10, page 36). Furthermore, a case study is performed to assess the practicality of the results of the study.  Hydro-treated vegetable oil, Bio Dimethyl ether, Liquefied Bio Methane/ ED95 are identified as fuels with considerable potential in the shorter term. Algal biofuel and Biomass to liquid (BTL) fuels from synthesis gas, if realized commercially would be a breakthrough for biofuels in overall transportation sector. However, life cycle analysis has to be performed for the different fuel pathways to completely understand the various impacting factors.

  • 3.
    Alkiswani, Mutaz
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Spectrum conversion in solar cells industry: Novel model concept and steps towards commercialization2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Solar photovoltaic industry is a hot research field, massive attempts are going on all over the world to increase its productivity in different ways. One of the challenges for solar cells is the light spectrum mismatch losses, which referred to the part of solar spectrum that cannot be utilized to electricity by the conventional cells.

    Two ways have been suggested to overcome solar spectrum mismatch losses, the first is multi layered cells (tandem cells) with a different light behavior for each layer, and the second is spectrum conversion which is this researches subject.

    Spectral modification or conversion in solar cells industry has been studied and different lab scale models have been introduced. According to nanoscale journal, such technology may be the base of the next generation solar cells, mentioning specifically the use of luminescence down conversion and up conversion techniques to control the light spectrum on the solar cell, these endeavors targets to produce solar cells that is not subjugated to Shockley-Queisser maximum efficiency limit of 31%.

    This research aims to draw a map of various ideas introduced to incorporate similar technologies in solar cell products, beside further suggestion to enhance its technical behavior and to push the commercialization of the technology forward. This is expected to reveal clear image about technology’s future development map for the upcoming studies, and to create a motivation for further studies towards a commercial production scale.

    The proposed commercialized model will result in enhancing the maximum theoretical efficiency limit to 48% if all spectral mismatch loses have been eliminated. Quantum energy level diagrams have been illustrated to describe each model’s performance under a theoretical light spectrum.

  • 4.
    Al-Mimar, Samer
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science. Halmstad University.
    Integration of solar and wind power at Lillgrundwind farm.: Wind turbine shadow effect on solar farm atLillgrund wind farm.2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

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

  • 5.
    Al-samuraaiy, Omar
    Halmstad University, School of Business, Engineering and Science.
    Efficiency comparison between Heat Pump andMicro CHP located in two different location inSweden2016Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

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

  • 6.
    Andersen, Niklas
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Ismail, Zahir
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Solel från ljudbarriär: längs Annetorpsvägen i Hyllie, Malmö2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

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

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

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

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

  • 7.
    Andersson, Gustav
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Ericsson, Emil
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Dark Ages Interferometer (DALI) Deployment Rover: Energy System2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The cosmic “Dark Ages” is the cosmic era between the epochs of recombination of cosmic microwave background and the formation of the first stars. The only signal from this epoch is from neutral hydrogen, which could represent one of the richest data sets in cosmology. In order to extract this data, NASA/JPL has proposed a rover mission to the farside of the moon to deploy several radio arrays. Here the arrays would gather data undisturbed by human interference. This thesis examines the possibility of using photovoltaic and electric batteries as an energy solution for a rover on the moon. The requirement for such a system to survive on the moon is discussed in a literature study. A proof of concept simulation using a Simulink model has also been done. The thesis concludes that a rover can deploy the radio array using solar energy. It would be able to hibernate through the night using radioisotope heating. It would need to wait for its batteries to charge before each night.

  • 8.
    Andreasson, Tobias
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Lindh, Emelia
    Halmstad University, School of Business, Engineering and Science.
    Förnybar energi på Svalbard2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This degree thesis investigates the possibilities of producing food inside a container at Svalbard, using renewable energy and energy storage. The idea was to be able to place the container at remote places without the need of being connected to the grid. We chose Svalbard, where it is cold and the sun is shining 24 hours a day at summertime. In the winter the opposite occurs and the sun is absent from the sky.

    The work is divided into theoretical studies and results based on different calculations. Such as economical evaluations (LCOE), and simulations using the computer programs Matlab and PVsyst. We have investigated if solar power and wind power is suitable as energy sources. Options for storage were batteries, grid and hydrogen storage. Different cases with Photovoltaics- and wind power plants, with batteries or grid, were compared against each other. It is not possible to use the grid as storage. This resulted in different sizing of our cases, with no excess energy production. The result showed that a 5 kWp photvoltaic plant with dual axis tracking system, was the most profitable. The Pay off would be 14 years and the total profit 63 453 SEK. If it will become possible in the future to use the grid at Svalbard as storage, it will open up opportunites for bigger systems. This will lead to higher profit than with smaller ones. Our results show that it is now most profitable with solar power.

  • 9.
    Averfalk, Helge
    et al.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Ingvarsson, Paul
    ÅF, Division Industry, Stockholm, Sweden.
    Persson, Urban
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Gong, Mei
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Large heat pumps in Swedish district heating systems2017In: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 79, p. 1275-1284Article in journal (Refereed)
    Abstract [en]

    Power-to-heat solutions like heat pumps and electric boilers are foreseen to be possible future tools to stabilise international power markets with high proportions of variable power supply. Temporary low cost electricity can be used for heat generation at times with high availability of wind and solar power through substitution of ordinary heat supply, hence contributing to increased energy system sustainability. Power-to-heat installations in district heating systems are competitive due to low specific investment and installation costs for large electric boilers, heat pumps, and heat storages. Several large-scale heat pumps were installed in Swedish district heating systems during the 1980s, since a national electricity surplus from new nuclear power existed for some years. The aim of this paper is to summarise the accumulated operation experiences from these large Swedish heat pumps to support and facilitate planning of future power-to-heat solutions with heat pumps in district heating systems. Gained experiences consider; installed capacities, capacity utilisation, heat sources used, refrigerant replacements, refrigerant leakages, and wear of mechanical components. The major conclusion is that many of the large thirty-year-old heat pumps are still in operation, but with reduced capacity utilisation due to internal competition from waste and biomass cogeneration plants in the district heating systems.

  • 10.
    Averfalk, Helge
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Ingvarsson, Paul
    ÅF, Division Industry, Stockholm, Sweden.
    Persson, Urban
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    On the use of surplus electricity in district heating systems2014In: Proceedings from the 14th International Symposium on District Heating and Cooling: September, 6-10, 2014: Stockholm, Sweden / [ed] Anna Land, Stockholm: Swedish District Heating Association , 2014, p. 469-474Conference paper (Refereed)
    Abstract [en]

    Maintained balance between supply and demand is a fundamental prerequisite for proper operation of electric power grids. For this end, power systems rely on accessibility to various balancing technologies and solutions by which fluctuations in supply and demand can be promptly met. In this paper, balancing approaches in the case of surplus electricity supply, due to long-term, seasonal, or short-term causes, are discussed on the basis mainly of compiled experiences from the Swedish national power grid. In Sweden, a structural long-term electricity surplus was created in the 1980s when several new nuclear plants were commissioned and built. One of four explicit domestic power-to-heat solutions initiated to maximize the utilization of this surplus electricity, as export capacities were limited, was the introduction of large scale electric boilers and compressor heat pumps in district heating systems. In retrospective, this solution not only satisfied the primary objective by providing additional electricity demand to balance the power grid, but represents today – from an energy systems perspective – a contemporary example of increased system flexibility by the attainment of higher integration levels between power and heat sectors. As European power supply will be reshaped to include higher proportions of fluctuating supply technologies (e.g. wind and solar), causing occasional but recurring short-term electricity surpluses, the unique Swedish experiences may provide valuable input in the development of rational responses to future balancing challenges. The main conclusions from this study are that district heating systems can add additional balancing capabilities to power systems, if equipped with electrical heat supply technologies, hereby contributing to higher energy system flexibility. Consequently, district heating systems also have a discrete but key role in the continued integration of renewable intermittent power supply technologies in the future European energy system.

  • 11.
    Barth, Henrik
    et al.
    Halmstad University, School of Business, Engineering and Science, Centre for Innovation, Entrepreneurship and Learning Research (CIEL).
    Bäckman, Emma
    Halmstad University, School of Business, Engineering and Science.
    Ellmarker, Josefin
    Halmstad University, School of Business, Engineering and Science.
    Sustainable Development for Food Waste: A Case Study of Catered Meal Service at Schools and Elderly Care homes2019In: Journal of Strategic Innovation and Sustainability, ISSN 1718-2077, Vol. 14, no 2, p. 21-34Article in journal (Refereed)
    Abstract [en]

    Food waste is an important topic in the context of sustainable development. Although many studies have addressed this topic, there is still limited knowledge owing to insufficient data. This study reports on food waste in two institutional settings in a Swedish municipality: schools and elderly care homes. The findings suggest it is easier to measure and reduce food waste in stable environments, such as exist at schools, than at environments characterized by change and unpredictability, such as exist at elderly care homes. Specific areas examined and compared include cooking and receiving kitchens, infrastructure, communications, and support. © North American Business Press.

  • 12.
    Barth, Henrik
    et al.
    Halmstad University, School of Business, Engineering and Science, Centre for Innovation, Entrepreneurship and Learning Research (CIEL).
    Melin, Martin
    Swedish University of Agricultural Sciences, Dept. of Work Sciences, Business Economics and Environmental Psychology, Alnarp, Sweden.
    A Green Lean approach to global competition and climate change in the agricultural sector – A Swedish case study2018In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 204, p. 183-192Article in journal (Refereed)
    Abstract [en]

    Increased global competition in the agricultural sector is rapidly changing the structure of farms and farming. As the number of small and diversified farms (often family-owned) decreases, the number of large and specialized farms (often corporate-owned) is increasing. In this transformation, the agricultural sector is more and more concerned with strategy, innovation, and competition in the effort to be more productive and more profitable. At the same time, the sector faces demands that it become more environmentally responsible in its policies and practices. This paper proposes a Lean Implementation Framework that small and mid-size farms can use as they aim to increase production and profit and yet support environmental sustainability. This case study takes an action-oriented research approach that focuses on the implementation of a Green Lean approach at 34 Swedish farms using various Lean tools. The paper describes how training sessions, farm visits, workshops, and counseling were used to introduce the farmers to the benefits and risks of the implementation of a new business model that added Green elements to the traditional business model design. The paper concludes with recommendations for adaptations to the Framework and suggestions for future research. © 2018

  • 13.
    Basavalingappa, Sharat
    Halmstad University, School of Business, Engineering and Science.
    Grid-Tied Solar Photovoltaic (PV) System with Battery storage: A Brief Techno-Economic Analysis2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Most of the world’s electricity is being generated through conventional sources of energy like coal and nuclear. People are realizing the dire effect of using these fuels, and the amount of CO2 being released into the environment. Therefore, in recent year there has been a shift in emphasis towards cleaner ways of generating electricity. One such recent trend is solar photovoltaics (PV), which has seen rapid growth over the years. This ever-increasing trend of adopting PV system allows consumers to be producers or “Prosumers”. Due to the irregular production capability of solar PV, the need for an energy storage system like a battery bank is on the rise as well. This report evaluates how solar PV can be used in combination with a battery bank to supply the annual electricity demand for a household with little to no support from the grid. The building is assumed to be located in Bangalore, India. The energy demand for the household is estimated based on the requirements of a basic Indian house standard. The size and configuration of each component have been done with regards to the total load demand. Furthermore, the cost of the whole system is estimated in order to evaluate the feasibility of the grid-tied system from an economic perspective. The results show that a PV system consisting of four 270W solar panels, a battery bank of eight150Ah lead-acid batteries and a 48V 4kW inverter is required to meet the annual energy demand of the house. The results show that from a technical standpoint, the above-mentioned technology is feasible. The results from the economic evaluation show that the localized cost of energy(LCOE) for the system is ₹6.01/kWh or € 0.078/kWh or 0.84SEK/kWh and the payback time for the given system is 16.19 years. On the bright side, there are new technological advancements in the PV field every day, which could mean that an energy system of this type can be an achievable and practical alternative.

    Most of the world’s electricity is being generated through conventional sources of energy like coal and nuclear. People are realizing the dire effect of using these fuels, and the amount of CO2 being released into the environment. Therefore, in recent year there has been a shift in emphasis towards cleaner ways of generating electricity. One such recent trend is solar photovoltaics (PV), which has seen rapid growth over the years. This ever-increasing trend of adopting PV system allows consumers to be producers or “Prosumers”. Due to the irregular production capability of solar PV, the need for an energy storage system like a battery bank is on the rise as well.

    This report evaluates how solar PV can be used in combination with a battery bank to supply the annual electricity demand for a household with little to no support from the grid. The building is assumed to be located in Bangalore, India. The energy demand for the household is estimated based on the requirements of a basic Indian house standard. The size and configuration of each component have been done with regards to the total load demand. Furthermore, the cost of the whole system is estimated in order to evaluate the feasibility of the grid-tied system from an economic perspective.

    The results show that a PV system consisting of four 270W solar panels, a battery bank of eight 150Ah lead-acid batteries and a 48V 4kW inverter is required to meet the annual energy demand of the house. The results show that from a technical standpoint, the above-mentioned technology is feasible. The results from the economic evaluation show that the localized cost of energy (LCOE) for the system is ₹6.01/kWh or € 0.078/kWh or 0.84SEK/kWh and the payback time for the given system is 16.19 years. On the bright side, there are new technological advancements in the PV field every day, which could mean that an energy system of this type can be an achievable and practical alternative.

  • 14.
    Berg, Nichlas
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Kårhammer, Per
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Säsongslagring av spillvärme: Ersättning av Halmstad fjärrvärmenäts spetslastanläggning2013Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In Sweden, a great deal of energy is used for residential and commercial heating. To fulfill the ever increasingly need for heat, new heating plants is built to complement the district heating system. At the same time there is unused energy in industry, which produces heat as an unwanted byproduct.

    This report evaluates the possibility to use this byproduct to supply energy to a district heating system and store it in seasonal heat storage. When the heat demand increases during the cold season of the year, the seasonal heat storage contributes with heat energy.

    The idea is to replace parts of the heating plants in Halmstad with heat storage and waste heat. The aim is to exclude usage of all fossil fuels. This report will also evaluate the economical prerequisites and environmental benefits in replacing biofuels.

    A steelworks company, Höganäs Halmstadverken, is situated in Halmstad. This industry could contribute with surplus heat, which is calculated in this report.

    With help of calculations and simulations in Microsoft Excel, a system with adequate heat storage method and surplus heat from local industry is formed. This system is optimized concerning economic and environmental matters.

    The results reveal that Halmstad's conditions are favorable to integrate pit heat storage and there is potential to deliver waste heat from Höganäs Halmstadverken steelworks. Sizes of seasonal heat storage is optimized to 200 000 m3 for replacing fossil fuels respectively 550 000 m3 for replacing fossil fuels and biofuels. Waste heat effect is calculated to 15 MW.

    The economical calculations results in an annual profit up to 8 million SEK with a payoff equal to 8 years. The environmental benefits consisting of reduced greenhouse gases are calculated to 4 800 tons carbon dioxide equivalents annually.

  • 15.
    Berkan, Yaroslav
    Halmstad University, School of Business, Engineering and Science.
    Simris lokala energisystem2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 16.
    Connolly, David
    et al.
    Aalborg University, Aalborg, Denmark.
    Lund, Henrik
    Aalborg University, Aalborg, Denmark.
    Mathiesen, Brian Vad
    Aalborg University, Aalborg, Denmark.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Möller, Bernd
    Aalborg University, Aalborg, Denmark.
    Persson, Urban
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Boermans, Thomas
    Ecofys, Köln, Germany.
    Trier, Daniel
    PlanEnergi, Copenhagen, Denmark.
    Østergaard, Poul Alberg
    Aalborg University, Aalborg, Denmark.
    Nielsen, Steffen
    Aalborg University, Aalborg, Denmark.
    Heat Roadmap Europe: Combining district heating with heat savings to decarbonise the EU energy system2014In: Energy Policy, ISSN 0301-4215, E-ISSN 1873-6777, Vol. 65, p. 475-489Article in journal (Refereed)
    Abstract [en]

    Six different strategies have recently been proposed for the European Union (EU) energy system in the European Commission’s report, Energy Roadmap 2050. The objective for these strategies is to identify how the EU can reach its target of an 80% reduction in annual greenhouse gas emissions in 2050 compared to 1990 levels. None of these scenarios involve the large-scale implementation of district heating, but instead they focus on the electrification of the heating sector (primarily using heat pumps) and/or the large-scale implementation of electricity and heat savings. In this paper, the potential for district heating in the EU between now and 2050 is identified, based on extensive and detailed mapping of the EU heat demand and various supply options. Subsequently, a new ‘district heating plus heat savings’ scenario is technically and economically assessed from an energy systems perspective. The results indicate that with district heating, the EU energy system will be able to achieve the same reductions in primary energy supply and carbon dioxide emissions as the existing alternatives proposed. However, with district heating, these goals can be achieved at a lower cost, with heating and cooling costs reduced by approximately 15%. © 2013 Elsevier Ltd.

  • 17.
    Connolly, David
    et al.
    Department of Development and Planning Aalborg University, Aalborg, Denmark.
    Lund, Henrik
    Department of Development and Planning Aalborg University, Aalborg, Denmark.
    Vad Mathiesen, Brian
    Department of Development and Planning Aalborg University, Aalborg, Denmark.
    Möller, Bernd
    Department of Development and Planning Aalborg University, Aalborg, Denmark.
    Østergaard, Poul Alberg
    Department of Development and Planning Aalborg University, Aalborg, Denmark.
    Nielsen, Steffen
    Department of Development and Planning Aalborg University, Aalborg, Denmark.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Persson, Urban
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Trier, Daniel
    PlanEnergi, Copenhagen, Denmark.
    The role of district heating in decarbonising the EU energy system and a comparison with existing strategies2013In: Book of Abstracts: 8th Conference on Sustainable Development of Energy, Water and Environment Systems, 2013Conference paper (Refereed)
    Abstract [en]

    Many strategies have already been proposed for the decarbonisation of the EU energy system by the year 2050. These typically focus on the expansion of renewable energy in the electricity sector and subsequently, electrifying both the heat and transport sectors as much as possible. In these strategies, the role of district heating has never been fully explored system, nor have the benefits of district heating been quantified at the EU level. This study combines the mapping of local heat demands and local heat supplies across the EU27. Using this local knowledge, new district heating potentials are identified and then, the EU27 energy system is modelled to investigate the impact of district heating. The results indicate that a combination of heat savings, district heating in urban areas, and individual heat pumps in rural areas will enable the EU27 to reach its greenhouse gas emissions targets by 2050, but at a cheaper price than a scenario which focuses primarily on the implementation of heat savings.

  • 18.
    Deutschmann, Oliver
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Johansson, Thomas
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Framtidens elbilar utmanar nutidens elnät: Påverkan av ett ökat antal elbilar på ett halländskt elnät2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The challenges facing low voltage grids are rising as an increasing number of domestic houses transition from fossil fueled heating to electricity based heating. Several environmental goals and visions have the same transition from fossil based power to electricity based power in mind for the transportation sector. One of the most important tools for this transformation is widely regarded to be the electric vehicle. With the demands of the electric vehicle pressuring the power grid, several questions arise regarding the growth of the electric vehicle market and what repercussions it may have on the grid. This paper focuses on a typical low voltage grid in southern Sweden and what effects a growing electric vehicle market may have on it. Through computer-assisted simulations based on several future scenarios regarding the EV market, this paper finds that few modifications and reinforcements are needed on this particular grid within the next 10 to 15 years. After this timeframe the voltage drop becomes a serious concern and should be addressed.

  • 19.
    Farah, Hamad
    Halmstad University, School of Business, Engineering and Science.
    Hybrid solar system for heat and electric demands in a simple housing within Sweden and China2019Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The access to ideal heating and power techniques has always been highly thought after.This is mainly due to the development in housing architecture and the cold nature of certain regions which has led to an increase in popularity of the heating market and modernised heating technologies. The current DH systems make use of CHP plants for thegeneration of power and electricity. These CHP plants for the most part, are powered through biomass and during winter periods the demand for heating is highly increased.The biggest issue with relying on biomass solely is the constant need to burn wasteproducts which not only results in increasing the demand for consuming in more waste,but also results in producing remains (by-products) that cannot be broken down further and hence might require the utilization of land-space (landfills) for their disposal. Solar modules on the other hand, have gained increased popularity in the recent age. This is mainly due their extremely high flexible ability in converting solar irradiance intoelectrical and thermal energies. This study will try to provide a comprehensive study intothe utilization of a hybrid solar system that combines a standard PV module with a flat-plate collector through estimating the energy demands for a simple housing within Sweden and China. This will be the main aim of the study, however the possibilities of integrating this hybrid solar system alongside current DH systems will mostly be discussed in the first sections to proof the possibility of executing such a system. The theoretical work carried out will only include simulations of having just separate,standalone PV and flat-plate collector modules. However, designing a hybrid solar and DH system will not be the major focus of this study. The results at the end of the report,concluded that the electrical production for the Swedish case were noticeably higher thanthat of the Chinese case in spite of maintaining the same load values through both cases and higher solar irradiation for the Chinese case. Due to PVsyst simulation constraints,the results show that the investment cost of the Swedish PV (electrical component) module was about 3.6 times greater than that of the Chinese which could possibly mean that the Swedish case has a bigger PV module area than the Chinese case in order to meetel ectricity demand monthly. However, when it came to the thermal energy production, it was possible to assume different collectors cases and hence an area of 7m2 was chosen for the Swedish perspective while an area of 4m2 has been considered for the Chinese case. The thermal useful energy values where then compared with heating demands for both of the cases. Finally, the thesis concluded that there was no requirement for having an integrated DH network within the standalone houses, having small electricity and heat demand and hence, it might be more beneficial to have an integrated DH and solar system within more densely populated housing areas.

  • 20.
    Farouq, Shiraz
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Byttner, Stefan
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Gadd, Henrik
    Öresundskraft AB, Ängelholm, Sweden.
    Towards understanding district heating substation behavior using robust first difference regression2018In: Energy Procedia, Amsterdam: Elsevier, 2018, Vol. 149, p. 236-245Conference paper (Refereed)
    Abstract [en]

    The behavior of a district heating (DH) substation has a social and operational context. The social context comes from its general usage pattern and personal requirements of building inhabitants. The operational context comes from its configuration settings which considers both the weather conditions and social requirements. The parameter estimating thermal energy demand response with respect to change in outdoor temperature conditions along with the strength of the relationship between these variables are two important measures of operational efficiency of a substation. In practice, they can be estimated using a regression model where the slope parameter measures the average response and R2 measures the strength of the relationship. These measures are also important from a monitoring perspective. However, factors related to the social context of a building and the presence of unexplained outliers can make the estimation of these measures a challenging task. Social context of a data point in DH, in many cases appears as an outlier. Data efficiency is also required if these measures are to be estimated in a timely manner. Under these circumstances, methods that can isolate and reduce the effect of outliers in a principled and data efficient manner are required. We therefore propose to use Huber regression, a robust method based on M-estimator type loss function. This method can not only identify possible outliers present in the data of each substation but also reduce their effect on the estimated slope parameter. Moreover, substations that are comparable according to certain criteria, for instance, those with almost identical energy demand levels, should have relatively similar slopes. This provides an opportunity to observe deviating substations under the assumption that comparable substations should show homogeneity in their behavior. Furthermore, the slope parameter can be compared across time to observe if the dynamics of a substation has changed. Our analysis shows that Huber regression in combination with ordinary least squares can provide reliable estimates on the operational efficiency of DH substations. © 2018 The Authors. Published by Elsevier Ltd.

  • 21.
    Farshori, Armaan Hussain
    et al.
    Halmstad University, School of Business, Engineering and Science.
    De Pablo Escribano, David
    Halmstad University, School of Business, Engineering and Science.
    Viability of a New Fender in Market and a New Fender Design Proposal for Small Vessels.2016Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This dissertation has been carried out for AB Halmstads Gummifabrik (HGF) during the spring of 2016. The purpose of this thesis has been to do a market research on the company’s fender and to give a fender design proposal for small vessels. The expectation in the future is that the design proposal may be implemented into an actual product by the company, and released in the market. The project began with a meeting at HGF with Zaheer, where he gave us an overview and details about the project as well as an explanation of how the project needs to be developed. The project was performed mainly by following the David Ullman’s Methodology. Criteria’s were set together with Zaheer to carry out the research, different ports in different countries from all of the Europe were shortlisted and contacted, especially covering the Scandinavian area. The company’s fender covered a huge range of vessels existing in the European region, but there was gap which existed with the private or small vessels (i.e. Yachts, motorboats, etc.) which were due to the reason that the company’s fender only covered the industrial mid-sized vessels (i.e. Cargos, Tankers, etc.) To fill up the gap a fender design had to be proposed which in turn had to have compatibility with the smaller vessels. Product development was carried out with concept generation and other functionalities. When a concept was finalized a 3D CAD model was made with the help of Unigraphics NX software and 2D drawings were made for future references. The result was a fender design which was simulated and analysed successfully for a range of small vessel berthing using the Altair´s Inspire software.

  • 22.
    Fältström, Mattias
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Ferdinandsson, Mikael
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Förutsättningar för absorptionskyla: Examensarbete på Öresundskraft2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The cooling demand increases in Sweden despite the cold climate, which could cause the increase of district cooling. District cooling is a centralized cooling system with multiple benefits such as safer operations, reduced failures and removal of rumbling that will otherwise occur in local cooling systems. That’s why the absorption chiller is becoming more and more interesting to incorporate indistrict heating.The purpose of this report is to give the company Öresundskraft the technical and economic conditions for absorption cooling in Helsingborg. The main goal with the report have been to investigate: which temperature from the district heating system will be used for the absorptions chiller, how the coefficient of performance affects the conditions of absorption chiller, different dimensions for absorption chiller, different placement options for absorption chiller, if the existing cool water storage tank can be used in the future, is it profitable to invest in an absorption plant. The main goal questions have been answered through interviews, compilation and calculation of data, examination of research literature and other literature. Conclusions the authors were able to find is that the absorption chiller should be sized to 2,2 MW and it should be placed on Västhamnsverket. Under the conditions that there was access to cheap heat and only operating during the summer the result to invest in an absorption plant was profitable.

  • 23.
    Gadd, Henrik
    et al.
    Oresundskraft AB, S-25106 Helsingborg, Sweden..
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Fault detection in district heating substations2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 157, p. 51-59Article in journal (Refereed)
    Abstract [en]

    Current temperature levels in European district heating networks are still too high with respect to future conditions as customer heat demands decrease and new possible heat source options emerge. A considerable reduction of temperature levels can be accomplished by eliminating current faults in substations and customer heating systems. These faults do not receive proper attention today, because neither substations nor customer heating systems are centrally supervised. The focus of this paper has been to identify these faults by annual series of hourly meter readings obtained from automatic meter reading systems at 135 substations in two Swedish district heating systems. Based on threshold methods, various faults were identified in 74% of the substations. The identified faults were divided into three different fault groups: Unsuitable heat load pattern, low average annual temperature difference, and poor substation control. The most important conclusion from this early study of big data volumes is that automatic meter reading systems can provide proactive fault detection by continuous commissioning of district heating substations in the future. A complete reduction of current faults corresponds to approximately half the required reduction of the current temperature levels in the effort toward future low-temperature district heating networks. (C) 2015 The Authors. Published by Elsevier Ltd.

  • 24.
    Gadd, Henrik
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Thermal energy storage systems for district heating and cooling2015In: Advances in Thermal Energy Storage Systems: Methods and Applications / [ed] Luisa F. Cabeza, Cambridge: Woodhead Publishing Limited, 2015, 1, p. 467-478Chapter in book (Refereed)
    Abstract [en]

    The context for this chapter is the current use and typical applications of thermal energy storages within contemporary district heating and cooling systems in the Nordic countries. Examples include a new assessment method, distributed heat storages, and hourly, daily, weekly, and seasonal heat and cold storages. Specific sizes have been estimated for 209 heat storages and 9 cold storages.

  • 25.
    Gelzinis, Adas
    et al.
    Kaunas University of Technology, Kaunas, Lithuania.
    Vaiciukynas, Evaldas
    Kaunas University of Technology, Kaunas, Lithuania.
    Kelertas, Edgaras
    Kaunas University of Technology, Kaunas, Lithuania.
    Bacauskiene, Marija
    Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Uloza, Virgilijus
    Kaunas University of Technology, Kaunas, Lithuania.
    Vegiene, Aurelija
    Kaunas University of Technology, Kaunas, Lithuania.
    Categorizing sequences of laryngeal data for decision support2009In: ECT 2009: Electrical and Control Technologies / [ed] Navickas, A, Kaunas: Kaunas University Technology Press , 2009, p. 99-Conference paper (Refereed)
    Abstract [en]

    This paper is concerned with kernel-based techniques for categorizing laryngeal disorders based on information extracted from sequences of laryngeal colour images. The features used to characterize a laryngeal image are given by the kernel principal components computed using the N-vector of the 3-D colour histogram. The least squares support vector machine (LS-SVM) is designed for categorizing an image sequence into the healthy, nodular and diffuse classes. The kernel function employed by the SVM classifier is defined over a pair of matrices, rather than over a pair of vectors. An encouraging classification performance was obtained when testing the developed tools on data recorded during routine laryngeal videostroboscopy.

  • 26.
    Ghadirinejad, Nickyar
    Halmstad University, School of Business, Engineering and Science.
    Design of an off-grid renewable-energy hybrid system for a grocery store: a case study in Malmö, Sweden2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    On planet Earth, fossil fuels are the most important sources of energy. However, these resources are limited and being depleted dramatically throughout last decades. Finding feasible substitutes of these resources is an essential duty for humanity. Fortunately, Mother Nature is providing us a number of good solutions for this crucial threat against our planet. Solar irradiance, wind blowing, oceanic and maritime waves are natural resources of energy that are capable of completely covering the annual consumption of all inhabitants on the Earth. In this research a set of components including “Northern Power NPS 100-24” wind generators, “Kyocera KD 145 SX-UFU” PV arrays, “Gildemeister 10kW-40kWh Cellcube” battery bank and HOMER bi-directional converter system were considered and successfully applied on HOMER tool and Particle Swarm Optimization (PSO) method. The main design goals of the presented hybrid system are to use 100% renewable energy resources in the commercial sector, where all power is produced in the immediate vicinity of the business place, adding strong advertising values to the setup. In order to supply hourly required load for a grocery store   (1000 ) in Malmö city with 115 kW peak load and 2002 kWh/d with maximum 0.1% unmet, the system was optimized to achieve minimum Levelized Cost of Energy (LCOE) and the lowest Net Present Cost (NPC). The HOMER simulation for quantitative analysis, along with a Particle Swarm Optimization (PSO) solution method is proposed and the results are compared. The results show that an optimized hybrid system with 3.12  LCOE, and power production of 28.5% by PV arrays and 71.5% by wind generators, is the best practice for this case study. 

  • 27.
    Ghebre, Temesghen Tesfazghi
    Halmstad University, School of Business, Engineering and Science.
    The Viability of Installing Mid-Size PV Solar Parks in Sweden: "A paper that evaluates the economic viability of installing mid-size PV solar parks ranging from 250 kW to 2 MW in the village of Åled."2017Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The ambition of the Swedish government is rapidly concentrating on the development of the

    renewable energy systems especially on wind energy, bio energy and solar energy. It has been

    observed on the growth of the production of electricity and heat from these three mentioned renewable

    energy systems. But, relatively in Sweden the share of production of electricity obtained from PV is

    quite smaller than the other two. The PV electricity production in Sweden comprises in a large scale

    of mainly the grid connected distributed PV systems and with a small number of installed solar parks.

    The aim of this paper is to analyze the viability of installing mid -size PV solar parks in Sweden and

    to simulate the effect of the proposed project in the village’s (Åled is the village where the proposed

    site is located) and the country’s electricity production. This study includes designing, simulation and

    financial analysis of different grid connected centralized mid -size capacities of PV solar parks of 250

    kWp,500 kWp,1MWp and 2MWp. They are all fixed ground mounted systems. Moreover, it also

    discusses the main reasons that hinders decision makers, the PV complications that are connected to

    the grid, Sweden’s energy regulations particularly the emission regulation and the financial policies

    of PV. Also, study visit, telephone and email contacts have supplemented it.

    This study was done with the collaboration of Nyedal Solenergi, in which the proposed site was

    owned by the company and this paper will be a future guide for the investment of the mid-size PV

    solar park. According to the study a discussion has been made with the grid supplier (EON) in that

    area on the investment on one of the designed projects which are presented in this paper.

    The results of the study show that the effect of the proposed systems on the production of electricity

    in the village of Åled was between 2.68 – 21.4 % and the impact on the country’s PV electricity

    production was 0.2 – 1.58 %. And, the possibility of installing mid-size PV solar parks generally in

    Sweden particularly in the proposed site is possible and economically it is viable but not profitable

    for system capacities less than 1 MW. As the IRR found for all capacities is greater than the estimated

    WACC, hence each proposed capacity has the possibility of paying back all its investment costs in

    about 23 years. So, the profitability is very low in case of the 250 kWp and 500 kWp but for the others

    they have about 7-8 years of profitability. A sensitivity analysis also has shown the impact of initial

    investment costs, O & M costs and electricity export rate on the IRR, NPV and equity payback. The

    initial investment cost and electricity export rate were seen with high effect on the IRR, NPV and

    equity payback. The LCOE calculated was higher than the average electricity spot price (300

    SEK/MWh) for 250 kWp and 500 kWp but lower for the other two capacities. The overall impact for

    the financial analysis was due to the decreasing of module prices, the rules that changes every year

    on electricity subsidies for renewables, tax reductions and rapid decreasing of electricity spot prices.

    In the future if the price of modules continues decreasing, spot price increases, more modification of

    the subsidy and introduction of new PV technologies integrated with other sources of energy is done

    then such projects could be more profitable.

  • 28.
    Gong, Mei
    Division of Energy Systems, Department of Mechanical Engineering, Linköping University, Linköping, Sweden.
    Exergy analysis of a pulp and paper mill2005In: International journal of energy research (Print), ISSN 0363-907X, E-ISSN 1099-114X, Vol. 29, no 1, p. 79-93Article in journal (Refereed)
    Abstract [en]

    Different energy and exergy concepts and methods are presented and applied to a Swedish pulp and paper mill. Flow diagrams show that the exergy content is mostly much less than the energy content of the flows. The largest exergy losses appear in the boilers. Heating processes are highly exergy inefficient. A limited Life Cycle Exergy Analysis (LCEA) shows that the exergy output amounts to over 3 times the spent exergy as non-sustainable resources. By replacing the present use of non-sustainable resources, mostly fuel oil, the mill could move towards a truly sustainable process. Copyright © 2005 John Wiley & Sons, Ltd.

  • 29.
    Gong, Mei
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Exergy and cost analysis of heating systems with energy storage2017Conference paper (Refereed)
    Abstract [en]

    About three quarters of the total final energy consumption is in the form of electricity and district heat and 49 TWh of district heat was used in Sweden in 2015. The energy supply and user demands vary and do not always match. The electricity production depends on the available energy resource that often is renewable, such as wind, solar and hydro power. The heat demand strongly depends on outdoor temperature and the weather conditions. Electricity and thermal storages are needed in order to reduce the losses from the lack of match between production and consumption. The cost of energy examined by others shows that electricity storage is about 100 times more expensive than thermal storage. However, in this study cost of exergy is only 20 times more for electricity than thermal. This study views electricity and district heat from source to end use and analyze the cost of exergy with storage. With a surplus of electricity the most efficient and cheapest way is to use electricity storage, such as battery or hydro storage on the purpose of electricity usage. The advantage of thermal storage depends strongly on the purpose of use, e.g. if it is for heating purposes. Heat pump is a method to convert electricity to district heat with 56% exergy efficiency. This paper will analyze different cases in order to give a more detailed discussion. Further studies of more cases are needed in the future.

  • 30.
    Gong, Mei
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    An assessment of district heating research in China2015In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 84, p. 97-105Article in journal (Refereed)
    Abstract [en]

    The recent growth of the Chinese district heating sector has been very high. No other country in the world can show the same growth rate during the last decades. The heated building area increased six times between 1995 and 2008. China has also enjoyed strong growth of scientific articles and papers about district heating in recent years. One third of all international scientific journal articles and conference papers about district heating came from Chinese scientists during 2010–2012, while Swedish scientists accounted for one quarter according to the Scopus scientific search engine. It is important to identify the Chinese district heating research to judge the potential for future collaborative research on district heating systems between Sweden/Europe and China. The 205 international publications on district heating by Chinese scientists published until 2013 have been mapped and summarised with respect to demand, supply, technology, market and environment. More diversified heat supply with renewable source was grasping the Chinese interest, since many new systems have been established, having more degrees of freedom when choosing various heat supply and technology options. The Chinese district heating systems were compared with sustainable district heating solutions in Sweden. Both countries would benefit from future research cooperation. © 2015 Elsevier Ltd.

  • 31.
    Gong, Mei
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Exergy analysis of network temperature levels in Swedish and Danish district heating systems2015In: Renewable energy, ISSN 0960-1481, E-ISSN 1879-0682, Vol. 84, p. 106-113Article in journal (Refereed)
    Abstract [en]

    Exergy concept is applied on district heating systems with different network temperature levels in their distribution networks. These district heating systems use a combination of renewables and heat recovery from other primary processes. The aim is to show simplicity and value of using exergy concept when comparing current and future temperature levels. Both the traditional exergy factor and the novel exergy utilisation rate are used in these analyses. Exergy utilisation rate expresses the ratio between the exergy delivered to customer heating systems and the exergy content in heat supply input to the distribution network. The analyses are performed on four different generations of district heating technologies, two national groups of district heating systems in Denmark and Sweden for revealing variations among systems, and two municipal systems for revealing variations within systems. The main conclusions are simplifications can be introduced in order to analyse the network temperature levels, current exergy factors reveal that current temperature levels can be reduced, and that almost two thirds of the exergy content in heat supply input are lost in the heat distribution chain. These conclusion will be vital input in developing the future fourth generation of district heating systems using both renewables and heat recovery. © 2015 Elsevier Ltd.

  • 32.
    Gong, Mei
    et al.
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, The Rydberg Laboratory for Applied Sciences (RLAS).
    Mapping energy and exergy flows of district heating in Sweden2017In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 116, p. 119-127Article in journal (Refereed)
    Abstract [en]

    District heating has been available in Sweden since the 1950s and used more than half of the total energy use in dwelling and no-residential premises in 2013. Energy and exergy efficient conversion and energy resources are key factors to reduce the environmental impact. It is important to understand energy and exergy flows from both the supply and demand sides. The exergy method is also a useful tool for exploring the goal of more efficient energy-resource use. Sankey diagrams together with energy and exergy analyses are presented to help policy/decision makers and others to better understand energy and exergy flows from primary energy resource to end use. The results show the most efficient heating method in current district heating systems, and the use of renewable energy resources in Sweden. It is exergy inefficient to use fossil fuels to generate low quality heat. However, renewable energies, such as geothermal and solar heating with relative low quality, make it more exergy efficient. Currently, about 90% of the energy sources in the Swedish district heating sector have an origin from non-fossil fuels. Combined heat and power is an efficient simultaneous generator of electricity and heat as well as heat pump with considering electricity production. Higher temperature distribution networks give more distribution losses, especially in exergy content. An outlook for future efficient district heating systems is also presented.

  • 33.
    Gong, Mei
    et al.
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Werner, Sven
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energiteknik.
    Mapping Energy and Exergy Flows of District Heating in Sweden2016In: Proceedings the 15th International Symposium on District Heating and Cooling: September 4th - 7th, 2016, Seoul, South Korea / [ed] Rolf Ulseth & Kyung Min Kim, 2016, p. 96-102Conference paper (Refereed)
    Abstract [en]

    District heating has been available in Sweden since the 1950s and used more than half of the total energy use in dwelling and no-residential premises in 2013. Energy and exergy efficient conversion and energy resources are key factors to reduce the environmental impact. It is important to understand energy and exergy flows from both the supply and demand sides. The exergy method is also a useful tool for exploring the goal of more efficient energy-resource use. Sankey diagrams together with energy and exergy analyses are presented to help policy/decision makers and others to better understand energy and exergy flows from primary energy resource to end use. The results show the most efficient heating method in current district heating systems, and the use of renewable energy resources in Sweden. It is exergy inefficient to use fossil fuels to generate low quality heat. However, renewable energies, such as geothermal and solar heating with relative low quality, make it more exergy efficient. Currently, about 90% of the energy sources in the Swedish district heating sector have an origin from non-fossil fuels. Combined heat and power is an efficient simultaneous generator of electricity and heat as well as heat pump with considering electricity production. Higher temperature distribution networks give more distribution losses, especially in exergy content. An outlook for future efficient district heating systems is also presented.

  • 34.
    Idris, Lina
    Halmstad University, School of Business, Engineering and Science. Swedish institute.
    Road map of the ultimate sustainable bio-fuel production from microalgae2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 35.
    Ingemarsson, Sebastian
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Pettersson, Per-Johan
    Halmstad University, School of Business and Engineering (SET).
    Economizer i bostadsvärmepumpar2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    I takt med stigande energipriser finner fler och fler det lönsamt att installera värmepump för att reducera sitt energibehov. Värmepumpar har dock svårigheter att tillgodose värmebehovet när utomhustemperaturen sjunker under -10°C. Detta problem kan minskas med så kallade economizerkopplingar, denna rapport jämför de båda economizersystemen flash tank cycle (FTC) och internal heat exchanger cycle (IHXC). Eftersom det har visat sig att vinsterna med economizerkopplingar är som störst då temperaturlyftet är stort är det mest intressant att jämföra dem i luft/vatten värmepumpar. Detta på grund av att övriga applikationer som berg-, jord- eller luft/luft-värmepumpar inte utsätts för samma stora temperaturvariation då utetemperaturen faller. Därför avgränsades rapporten till att endast omfatta economizerkopplingar i luft/vatten värmepumpar. Syftet i rapporten har växt fram ur den strävan som finns i att ständigt energieffektivisera vår bostadssektor vad det gäller uppvärmning, där värmepumpar idag har en viktig roll. Bakgrunden i rapporten är relativt omfattande för att ge läsaren den nödvändiga informationen för att sätta sig in i resultatet. Bakgrunden, eller den allmänna tekniska beskrivningen, innehåller bland annat övergripande beskrivningar beträffande de vanliga komponenterna i en värmepump, definition på en economizer samt vilka möjligheter economizern ger. Metoden för arbetet bestod i en litteraturgranskning där jämförelser som lett fram till resultatet togs ur artiklar från andra experimentella försök inom området. Nyckeltal som jämfördes var COP (Coefficient Of Performance), elanvändning, kyleffekt och värmeeffekt vid låga förångningstemperaturer. Resultaten pekade på att FTC-systemet har en fördel jämtemot IHXC vid kallare klimat på grund av sin bättre värmeeffekt och högre COP. Däremot drogs slutsatsen att IHXC har fördelar som noggrann reglerkapacitet och större tolerans vid val av köldmedie eftersom ingen fasseparation med tillkommande problem sker i denna koppling. När värmepumpsprocessen vänds och används till kylning kommer rapporten fram till att skillnaden mellan de två systemen är försumbar.

  • 36.
    Ivarsson, Johanna
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Solceller för flerbostadshus: En teknisk rapport för HFAB2011Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This examination paper is about the potential for Solar cells on apartment blocks. The technology with using solar cells for manufacturing electricity, has been on the market for a while, but recently the new installations of solar cells has increased. Solar cells are suited for placements on buildings but are expensive to obtain. The municipal real-estate company is interested in solar cells but wants to know more before they invest in the technology. This report contains an account of the solar cell and a guide to how a connection to the grid is accomplished. The report even contains suggestions of where the solar cells can be located and an estimate of annual production of electricity on a building. The outcome of the report is that there are good prerequisites for solar cells on apartment blocks and it shows the real- estate company as an environmental-thinking corporation.

  • 37.
    Jalaei, Fatemeh
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Application of a mathematical approach in modeling wind time series: A general survey of the Langevin method2015Independent thesis Advanced level (degree of Master (One Year)), 40 credits / 60 HE creditsStudent thesis
    Abstract [en]

    Today, the great importance and benefits of renewable energies as a source of endless energy is obvious for all.

    Wind is recognized as one of the most stable and safest type of energy, due to ease of access as well as applying modern technical and scientific methods in order to its extraction.

    In this regard, much effort has been done in the developed societies to obtain knowledge besides getting access to new techniques in the exploitation of this unlimited wealth.

    Apart from the new aspects of the proposed research in wind area, the extraction operation requires specialists to advanced techniques and scientific research.

    The development of societies and their increasing necessity to energy resources have increased the importance of safe and clean renewable energy.

    This study investigates a technique to specify the power performance of the wind turbine directly from measured data which fluctuate with high frequency. This project is a review of a dynamical method for the specification of wind turbines' power curves.

    Considering the power output of a wind turbine in this study, the basic concept is to divide its dynamics into two components; a deterministic(relaxation) and a stochastic(noise) functions which are equivalent to the wind turbines' real behavior itself and the exterior wind turbulence.

    It specifically presents a procedure to estimate the reaction of the wind turbine as a machine to the wind speed dynamically.

    In this method, reconstruction of the coefficients from the measured data and extraction of the specification of the power output have been done. The main focus of this technique is on differential equations which are recognized as Langevin equations.

    As the consequence, it is shown; with this method we will be able to percept the conversion dynamics of wind turbines and get the power curves' results with high precision. The results demonstrate that power performance's specification is accurately reconstructed from the measured data by the quick estimation of the coefficients from data.

    Furthermore, the high accuracy and fast estimation of the power curves would be considered as preferences in this method.

  • 38.
    Janssen, Sabine
    et al.
    TNO Department of Environment and Health.
    Vos, Henk
    TNO Department of Environment and Health.
    Eisses, Arno R.
    TNO Department of Environment and Health.
    Pedersen, Eja
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS).
    Predicting annoyance by wind turbine noise2010Conference paper (Refereed)
    Abstract [en]

    While wind turbines have beneficial effects for the environment, they inevitably generate environmental noise. In order to protect residents against unacceptable levels of noise, exposure-response relationships are needed to predict the expected percentage of people annoyed or highly annoyed at a given level of wind turbine noise. Exposure-response relationships for wind turbine noise were derived on the basis of available data, using the same method that was previously used to derive relationships for transportation noise and industrial noise. Data from surveys in Sweden and the Netherlands were used to achieve relationships between Lden and annoyance, both indoors and outdoors at the dwelling. It is shown that a given percentage of annoyance by wind turbine noise is expected at much lower levels of Lden than the same percentage of annoyance by for instance road traffic noise. Results were used to guide new noise regulation for wind turbines in the Netherlands.

  • 39.
    Jensen, Henrik
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Solcellsanläggningars kostnadseffektivitet för elkrävande verksamhet: Lönsamhet, miljöavtryck och självförsörjningsgrad för solcellssystem med olika orientering2016Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    The primary aim of this thesis was to use the calculation instrument for the solar energy potential map of Landskrona to simulate several PV systems to a sanitation company. The calculation tool is designed to calculate the profitability and environmental benefits of installing solar panels. The calculation tool was adapted in order to compare cost efficiency, environmental benefit and degree of self-sufficiency and self- consumption for the solutions. The PV system was planned to a company, Landskrona Svalöv Renhållning (LSR).

    Furthermore, four different ways to construct the PV system were investigated; flat against the roof, tilted with respect to the roof, tilted with respect to the roof and oriented (azimuth angle), as well as an installation with a string of tilted PV modules together with PV modules mounted flat against the roof. Variation of the system configurations was achieved by changing the parameters tilt and azimuth angle. The capacity was adjusted so that the annual production would be 83 500 kWh for all the studied systems. The different systems were optimized in two ways; first for the most output per module, and secondly for the greatest self-sufficiency in order to minimize the losses of excess production.

    PV modules optimally oriented for production per module provides the highest profitability and lowest payback period. The study suggests that photovoltaic systems are a competitive installation for LSR even without subsidies.

    The degree of self-consumption was 11 %. Simulation results showed that the degree of self-sufficiency could only be increased marginally by simply changing the orientation of solar cells (with power adapted to maintained production level). There was no significant benefit from tilting the solar cells by 90 ° to increase self-sufficiency in the winter.

    The simulations showed that almost all of the produced electricity was used to LSR 's internal load. This high degree of self-consumption showed very little excess electricity was produced. LSR is connected to the medium voltage power grid via two transformers. The surplus production covered only part of the no-load losses in transformers. Surplus electricity could therefore not be sold, but the high self-consumption rate limited this loss of revenue.

    The solar electricity from crystalline silicon cells, results in slightly higher greenhouse gas emissions than wind power but much lower than the production mix of electricity available in the market. The self-produced solar electricity contributed to the environment because LSR did not have to buy the contracted wind electricity, which then became available for others.

    The study's conclusions are that a PV system is likely to be profitable for LSR. Self-sufficiency would be about 11%, and the self-consumption rate of 98%. The environmental benefit consisted of the contribution of renewable energy in the mix of electricity generation on the market.

  • 40.
    Johannesson, Josefin
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Pålsson, Lisa
    Halmstad University, School of Business, Engineering and Science.
    Vetenskaplig metod för inventering av betydande miljöaspekter2018Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
  • 41.
    Johansson, Alfred
    Halmstad University, School of Business, Engineering and Science.
    Hållbar vattenkraft i Nissan: En förstudie och konsekvensutredning över förutsättningarna för ökade vandringsmöjligheter med nya fiskvägar.2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The hydropower from Nissan River is of national interest and produces annually 230 GWh from the twelve power stations in the main flow. For modified waters a consideration between the power production and the biological values has to be made. This reports serves as a pre-study for Nissans Vattenråd. It tries to evaluate some of the biological values in the Nissan basin and map the power production in the area. And the size and value of lost power production from new fishways for the twelve stations in the main flow.

    The investment of new fishways is calculated using simplified templates with values from the business. The cost and loss of power due to new fishways are calculated for three cases: fish friendly grates for the power station inlet and bypass for migration. Fish friendly grate and vertical-slot fish passage for migration. The last case is called “scenario” and is a combination with the most suited solution for each station. This includes a restoration of the creek, with maintained power production, for the two stations closest to the ocean.

    The cost for fish friendly grade and bypass for al stations is about 207 mskr and for vertical-slot fish passage 125 mskr. They both result in a loss of power production of 12 GWh/year, corresponding to a value of 3,2 mskr (NordSpot sale price only) annually. Case “scenario” costs 177 mskr and loses additionally 4,2 GWh/year.

    In the overview, large parts of the Nissan runoff has difficulties reaching “god ecological status” which is the goal set for 2021. This goal can be extended to 2027. The main problem is chemical effect of acidification and mercury in the ground, as well as connectivity issue caused by dams and culverts. Salmon and sea trout could earlier migrate to Nissafors and is limited to the lower parts of Nissan to Oskarström. Many of the tributary waters have high biological values. The existing fishways have questioned functionality and delays fish migration today. Before decisions are made about increasing fishways the advice is to do further studies about the breeding grounds. It’s also possible to identify positive cash flows from an increase in fish migration.

  • 42.
    Jönsson, Linnea
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Sänkt returtemperatur: Potentiell besparing i fjärrvärmesystem2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Optimizing energy systems is, in Sweden, as in many other countries, of growing interest. District heating systems are no exception. In 2012, 285 out of 290 municipals in Sweden had district heating in use and the majority of these systems have a higher return temperature than that which is possible with an error-free substation of day current technology. To, when possible, lower the return temperature is a way of increasing the effectiveness of the district heating system.This study means to investigate, through simulations and calculations, how big of a reduction in production cost a lower temperature in the city of Ystad’s district heating system would correspond to. The results show that a cold year, such as 2010, 1.8 SEK of the production cost could be saved per MWh sold heat for a whole year and 1°C temperature lowering. Equivalent value for a warm year such as 2011 was concluded to be 1.2 SEK/MWh,°C.

  • 43.
    Jönsson, Linnea
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Energy Science.
    Thermal energy storage systems in an energy company's district heating system: Exploring ways of handling daily and seasonal heat load variations in Höganäs2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
  • 44.
    Kalén, Jonas
    et al.
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Åkerlund, Nathan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Energiteknik.
    Gårdsbaserad biogas på Nya Skottorp: utvärdering och optimering av anläggningen och uppgradering av biogasen2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Biogas is an expanding sector within the broad field of agriculture and animal production. Small-scale biogas offers local combined power and heating production and the substrate is transformed into high-quality biological fertilizer. This bachelor thesis focuses on a pig farm in south-western Sweden, where biogas is produced from pig manure, evaluates and suggests ways of optimizing the process and investigates whether investing in an upgrading plant would be a feasible and more cost-efficient option. The results show that the biogas plant is working well, although the production differs from the original plans. This shows in turn that planning and examining the basic conditions before making the investment is of great importance, as well as monitoring and keeping detailed statistics of the running process. Logistical factors make optimizing the process through additional substrates difficult. The thesis shows that investing in a Biosling upgrading plant would be a profitable option, supposing that the upgraded gas is sold via the natural gas infrastructure. Furthermore, many farmers are interested in producing their own fuel for tractors and other machines, which offers more future alternatives for the upgraded biogas. However, biogas producers in Sweden today are not offered any particular subsidies, which makes it especially hard for small-scale producers.

  • 45.
    Khan, Imran
    Halmstad University, School of Business and Engineering (SET).
    Effects of hydraulic load on nitrate removal in surface-flow constructed wetlands2011Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Abstract

    Constructed wetlands had been widely used as economical and environment friendly treatment systems for agriculture runoff in southwest Sweden to limit the transport of nutrients to Kattegat, thereby aiding in the effort of abating eutrophication. The extensive use and acceptance of wetlands as treatment systems had been an incentive to develop performance models. Even recent studies showed that first order models are inadequate to guide the design of constructed wetlands, these are still commonly used. The main assumption of such models is tested here, which states that the removal rate of pollutant(s) is proportional to concentration in a constructed wetland. For this purpose experimental wetlands in Plonninge near Halmstad (southwest of Sweden) were selected and divided into two groups (9 each). They were fed with different hydraulic loads achieving 4 and 8 days residence times. The data obtained from the analysis of total nitrogen and nitrate were tested with first order equations and found that these models are sufficient to describe the nitrate removal in nitrate rich experimental wetlands.

    Key words: constructed wetlands, hydraulic load, first order kinetic models, eutrophication, nitrogen removal

  • 46. Kjellander, Matilda
    et al.
    Tengvall, Anders
    Design of a small scale hybrid photovoltaic and wind energy system2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Approaching problems with global warming due to the use of fossil fuels, means that new system solutions have to be investigated. This report investigates the possibility to expand an existing photovoltaic system with a wind turbine generator to simplify the expansion of renewable energy sources. Through an extensive literature study and simulation in SIMULINK the result has been developed and tested. It shows that it is possible to connect a wind turbine generator to the same inverter as the PV-modules if no MPPT algorithm for the PV-modules is integrated. To protect the inverter a dump load has to be connected. Because of the complexity a DC-coupled system brings, AC-coupling is advised when expanding PV-modules with a WTG. The optimal wind turbine is considered to be a permanent magnet synchronous generator connected to the AC-bus through a full-effect inverter. The turbine should be chosen according to the intended location based on wind conditions and desired energy production.

  • 47.
    kollappillai Murugan, Sai Varun
    Halmstad University, School of Business, Engineering and Science.
    Analysis of Hybrid Offshore Floating Wind and Marine Power2018Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Wind energy is a major part of renewable energy production. With fossil fuel depletion and climate change at the cusp, it is an absolute need to implement or evolve the current source or utilization of renewable energy. The wind has been dominating the onshore for many decades and offshore wind turbines are available at shallow depths.  To extract more wind energy source deep sea location is recommended. Also, in deep seas, ocean current energy is utilized very sparsely compared to the dominating wind and solar energy. So far no hybrid offshore horizontal axis and ocean current system are in existence.

    Based on the depth of the sea water the offshore floating structure is classified. Usually, for any floating structure stability is an apprehension. In an offshore floating structure, the damping with respect to the thrust force exerted on the wind turbine will affect the life of the wind turbine. During high wind speed, the angle of inclination would go up to about 4 degrees. The time required for the floating structure to come to rest may also be high. We present an analysis based on an existing floating structure which is a ballast stabilized the floating structure. In this paper, we add an additional submerged turbine and do a 2D analysis on the floating structure to find out whether the structure’s oscillation is well damped or not. We also discuss whether the weight of the submerged will influence the stability or by changing the radius of blades of the submerged turbine will affect the damping.

  • 48.
    Kronebrant, Mattias
    Halmstad University, School of Business, Engineering and Science.
    Cost comparison of solar home systems and PV micro-grid: The influence of inter-class diversity2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Nearly one fifth of the global population lacks access to electricity and electricity access is essential for economic growth and human well-being. SHSs and micro-grids both have the possibility of increasing the electricity access in developing countries. The decision to choose either SHSs or micro-grids for rural electrification is a complex task that must consider both the technological factors that separate these two systems and the non-technological factors. Separate times of peak load between households (inter-class diversity) has shown to be one major advantage for the use of micro-grids. Studies have shown that the diversity factor present in micro-grids can scale down the necessary capacity of PV modules and energy storage of up to 80%, in comparison to stand-alone systems (e.g. SHSs). These reductions are nevertheless based on assumed diversity factors, not using real load profiles and the necessary capacities are calculated using intuitive methods (known to be inexact).

    From interviews in a rural community of Nicaragua, the author generated load profiles and determined the diversity factor of the community. The load profiles were generated with a specially designed software to formulate realistic load profiles for off-grid consumers in rural areas. These load profiles were later used in the software HOMER where the diversity’s influence on required capacity and NPC were determined by comparing SHSs to a PV based micro-grid. The study showed that the required capacity and NPC of the inverter and charge controller are clearly decreased as an influence of inter-class diversity. The required PV and battery capacity are also decreased when a micro-grid is utilized, but these reductions are most likely a result from the limited nominal power per component considered in HOMER.

  • 49.
    Landqvist, Anton
    et al.
    Halmstad University, School of Business, Engineering and Science.
    Eklund, Gustav
    Halmstad University, School of Business, Engineering and Science.
    Analys av en spänningshöjning på ett mellanspänningsnät2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report analyses the consequences of an increased voltage level in a medium voltage gridfrom 6 kV to 12 kV alternatively to 20 kV. The report examines an existing electricity grid insouthern Sweden, owned and operated by the power company Mellersta Skånes Kraft ek. För.(MSK). It consists of 177 transformers, has approximately 2500 customers and transferred 32GWh (incl. losses) in 2016.The report is divided into three parts, the first part addresses the technical aspects of an increasedvoltage level, the second part addresses the economic consequences that this implies and thethird part presents the conclusion and discussion.The grid was simulated in Nepal software and electrical calculations were performed on 12different operating modes, one for each month of the year. The loads in the network weredetermined by using Velander's method. Information and input-data of network componentswere obtained through product sheets, direct contact with manufacturers and MSK and as wellas through various literature.The report shows that an increased voltage level in the grid reduced transmission losses andresulted in lower costs for the grid owner. It also brought other technical benefits, such as lowervoltage drops, lower load intensity of network components, and lower short circuit current. Ahigher voltage level increased the network's generation of reactive power.The grid company’s revenue frame changes with an increased voltage level, partly because of thebonus that is obtained through efficient utilization of the grid, partly by replacing certaincomponents in the grid. The profitability of investments imposed by an increased voltage levelquickly became complicated due to several factors. Including what type of components thatneeded replacement, the capital structure of the investment and the electricity company's rate ofinterest. In the profitability analysis, the report uses the internal rate of return method.In the case of MSK it was assumed that all the power grid transformers needed replacement withan increased voltage level, thus increasing the revenue frame for the next supervisory period byapproximately 3.4 million SEK. The internal rate of return for the investment was found at 4.62%.However, some uncertainty exists about several components (cables, wires and transformers) inthe grid, which may affect the profitability of the investment and the grid’s capability to handle anincreased voltage level in its present state.

  • 50.
    Larsson, André
    et al.
    Halmstad University, School of Business and Engineering (SET).
    Hild-Walett, Dennis
    Halmstad University, School of Business and Engineering (SET).
    SOLPANELERS MÖJLIGHETER, EN AKTUELL RAPPORT FÖR MONTAGE PÅ FASTIGHETEN KORNHILL2012Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    This thesis deals with the possibilities of installing solar panels on a property, the building is owned by Kornhillschurch and called Kornhill. The owners of the property wanted to learn more about potentials for installation of solar panels on the property, therefore we described different types of solar cells and solar cells essential function to generate electricity in the report. Different factors that are limiting the generated energy are mentioned.

    An investigation of the property’s potential has been made in order to consider different designs. When sites that were considered suitable for solar cells were selected, different design options were made, one for each site. Then a number of financial calculations on the dimensioned plants were made to see if each plant will be profitable.

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