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  • 1.
    Ackeby, Susanne
    et al.
    STRI AB.
    Tjäder, Jonas
    Bastholm, Caroline
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    The role and interaction of microgrids and centralized grids in developing modern power systems2017Konferensbidrag (Refereegranskat)
    Abstract [en]

    An extension of microgrids is now underway, primarily to allow increased electrification in growing economies but also to meet the need to reduce global CO2 emissions and to provide ancillary services to centralized grids. Energy access constitutes one of the fundamental building blocks for economic growth as well as social equity in the modern world. Access to sustainable energy is needed to achieve sustainable development. A microgrid should not be seen as a competitor to the centralized grid but as a complement.Through examination of several implemented cases from different parts of the world the following topics are considered: Analysis of the interaction between centralized grids and microgrids Analysis of stakeholder decision parameters for electrification Analysis of design differences and requirements for microgrids, depending on the intended purpose and the need of the end customer.It is determined that good planning, suitable requirements and clear regulations for microgrids (in relation to centralized grids) limits the risk of stranded assets and enables better business cases for the involved stakeholders.The paper is based on the discussion paper The role and interaction of microgrids and centralized grids in developing modern power systems – A case review publiced by ISGAN (International Smart Grid Action Network) Annex 6: Power T&D Systems.The discussion paper and further information about ISGAN is available at http://www.iea-isgan.org/.

  • 2.
    Andersen, Martin
    et al.
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik. Chalmers University of Technology.
    Bales, Chris
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Dalenbäck, Jan-Olof
    Chalmers University of Technology.
    Techno-Economic Analysis of Solar Options for a Block Heating System2016Ingår i: Conference Proceedings: Eurosun 2016, Palma De Mallorca: International Solar Energy Society, 2016, , s. 16Konferensbidrag (Refereegranskat)
    Abstract [en]

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

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  • 3. Andrén, Lars
    et al.
    Persson, Tomas
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Lennermo, Gunnar
    Handbok för kombinerade sol- och biovärmesystem: Teknik - System - Ekonomi2012Rapport (Övrigt vetenskapligt)
    Abstract [sv]

    Handboken beskriver olika solfångarkonstruktioner och solvärmekretsens ingående komponenter och ger en grundlig inblick i ackumulatortankens konstruktion och funktion. I boken finns förslag på systemutformning, olika tekniska lösningar och hur systemen bör styras och regleras. Handboken beskriver i första hand utformning-lösning-styrning av kombinationen sol- och pelletsvärme, men tar även upp solvärme i kombination med vedpannor, värmedrivna vitvaror och värmepumpar. Värmesystem med vattenburen värme är utmärkta att kombinera med solvärme, men det är i de flesta fall enklare att få till bra lösningar vid nyinstallation, än vid komplettering av befintlig anläggning. När solvärme och pelletsvärme ska kombineras finns det många alternativ till systemutformning. Det är viktigt att vattenburna pelletssystem utformas korrekt och kombineras på rätt sätt med solvärme för att komforten ska bli hög och elanvändningen låg. Vattenmantlade pelletskaminer med ett vattenburet värmesystem är extra intressant i kombination med solvärme. När eldningen upphör i samband med att värmebehovet avtar kan solvärmen ta över. En generell slutsats är att konventionella svenska pelletspannor med inbyggd varmvattenberedning inte är lämpliga i kombination med solvärmesystem. Den typen av bränslepannor ger komplicerade systemlösningar, höga värmeförluster och det är svårt att åstadkomma en tillräckligt bra temperaturskiktning i ackumulatortanken om varmvattenberedning sker i pannan. Solvärme för varmvattenberedning kan vara ett enkelt och bra komplement till pelletskaminer som genererar varmluft. För solvärmesystem är det viktigt att kraftig temperaturskiktning erhålls när värmelagret laddas ur. Det betyder att ackumulatortankens (eller varmvattenberedarens) nedre vattenvolym ska kylas ner till temperaturer som ligger nära ingående kallvattentemperatur. Ackumulatortankens mellersta del bör kylas till samma temperatur som radiatorreturen. Vid design av solfångarkretsen måste överhettning och stagnation kunna klaras utan risk för glykolnedbrytning eller andra skador på värmebärare eller rörkrets (och andra komponenter i kretsen). Partiell förångning minskar risken för att glykolen skadas då solfångaren når höga stagnationstemperaturer. Solfångarens glykolblandning tillåts koka (förångas) på ett kontrollerat sätt så att endast ånga blir kvar i solfångaren. Vätskevolymen i solfångaren samlas upp i ett större expansionskärl och systemet återfylls när vätskan kondenserar. Dränerande solfångarsystem med enbart vatten är ett möjligt alternativ till konventionella solfångare. De kräver en större noggrannhet vid installationen, så att sönderfrysning undviks. Dränerande systemlösningar är relativt ovanliga i Sverige. Om solfångaren under senhöst-vinter-tidig vår kan arbeta med att förvärma kallvatten från 10 till 20 ºC erhålls en betydligt bättre verkningsgrad på solfångaren (och framför allt ökar värmeutbytet då drifttimmarna ökar väsentligt) än om radiatorreturen (som i bästa fall ligger på temperaturnivån 30 - 40 ºC) ska förvärmas. Därför bör radiatorreturen placeras en bra bit upp från botten i ackumulatortanken och tappvarmvattnet ska förvärmas i en slinga som börjar i tankens botten. Om det finns ett VVC-system måste systemet anslutas på ett speciellt sätt så att ackumulatortankens temperaturskiktning inte störs. En viktig parameter vid ackumulatortankens utformning är att värmeförlusterna hålls låga. Det är viktigt för att klara tappvarmvattenlasten med solvärme under mulna perioder sommartid (men också för att hålla energianvändningen låg). I moderna hus, där ackumulatortanken i regel placeras i bostaden, blir det en komfortfråga att undvika övertemperaturer i det rum där värmelagret placeras. En bra standard på isoleringen (med minimerade värmeförluster) kräver att det finns ett lufttätt skikt över hela isoleringen som dessutom sluter tätt mot röranslutningar. Ofrivillig självcirkulation i anslutande kretsar som kan kyla av och blanda om ackumulatortankens vattenvolym, bör förhindras med backventiler och nedböjning av rören i isolerskiktet eller direkt utanför tanken.

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  • 4.
    Azad, Mohammad
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Evaluation of an Energy System for multi-family houses with Combination of Exhaust Air Heat Pump and PV: Case Study: Demonstration Building of The EU Energy Matching Project, Sweden-Ludvika2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This thesis investigated application of the heat recovery ventilation using an exhaust air heat pump and a roof top photovoltaic (PV) system for a group of three multi-family houses located in Ludvika, Sunnansjö. The buildings in the existing condition have mechanical ventilation and a centralized heating system consists of a pellet boiler as the main source and an oil boiler as back up.

    Exhaust air heat pump (EAHP) has been known by the previous relevant researches as an effective solution to promote the energy efficiency in the buildings. Furthermore, reduction in PV cost has made the PV as a financially viable option to be contributed in supplying electricity demand.

    In this respect, this thesis aimed to calculate the potential of energy saving in the case study using the combination of EAHP and PV. For this purpose, the buildings and the proposed energy system were simulated to enable the comparison of energy demand before and after the renovation. The simulation was gradually progressed through several phases and each stage created the prerequisites of the next.

    Since the buildings were relatively similar in terms of boundary conditions, one of the buildings were initially modeled and the concluded space heating (SH) demand was extrapolated to the three buildings scope. The simulation of the building was done using 3dimensional thermal model offered by Trnsys3d. The primary results were also calibrated against the available annual fuel consumption data. In the second phase, a pre-developed TRNSYS model of the energy system was completed using the result of previous step as the total SH demand as well as the estimated domestic hot water (DHW) consumption from a stochastic model. This simulation produced the electricity demand profile of the heat pump when the heat pump provided the total heat demand. Subsequently, the electricity consumption of the flats and operational equipment were estimated using stochastic model and available monthly measurement, respectively.

    Since the feasibility and optimal placement of 74 𝑘𝑊 PV modules offered for these buildings had been already examined by the author in another study, the final simulation were performed in an hourly basis considering PV production and total electricity demand; i.e. EAHP, flats consumption and operational equipment.

    The results of the simulation showed that 21 % of total electricity demand during a year could be supplied by the proposed PV system even without any electrical storage, whereas 74 % of total yearly PV production is consumed by the local loads. The results also proved that removing old inefficient oil boiler and supplementing the pellet boiler with the combination of EAHP and PV could mitigate the annual purchased energy (including electricity and pellet) by approximately 40 % compared to the current condition.

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  • 5.
    Bales, Chris
    et al.
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Betak, Jan
    Broum, Michal
    Chèze, David
    Cuvillier, Guillaume
    Haberl, Robert
    Hafner, Bernd
    Haller, Michel
    Poppi, Stefano
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Weidinger, Alexander
    Optimized solar and heat pump systems, components and dimensioning: Deliverable 7.3 - MacSheep - New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance2015Rapport (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    This report describes the optimised solar and heat pump systems developed in the MacSheepproject as well as the simulation results for these systems. Four systems have been developed by four different development groups, each with one private company participating. The development groups have chosen different types of systems as well as different target loads for their systems, which give a wide coverage of the potential markets. The aim of the project was to achieve a 25% performance increase compared to state of the art systems, while being cost-competitive compared to the state of the art.Two reference state of the art solar and heat pump systems have been defined, modelled,and simulated to derive benchmark electricity demands and SPF values for the boundary conditions that were defined for the MacSheep project. The reference systems usedtheground (boreholes) orair as a heat source for the heat pump. The chosen boundary conditions were the climates of Zurich and Carcassone, arealistic DHW load,and two buildings, one representing a modern low energy building (SFH45) and one representing an existing building (SFH100). These reference systems and boundary conditions were defined within the first year of the project, and are used throughout the project.New components were developed for the MacSheepsolar and heat pump systems and these developments are reported in the reportsof work packages 3 –6. Component models have been programmed and validated with laboratory measurements.In this report, simulation results for the four MacSheep systems arecompared to the relevant reference system in order to quantify the expected performance increase. These simulations include the component models with their validated parameters and performance obtained from phase 3 of the project.In addition, the costs of the systemswere estimated. The key performance indicator for the final system developments was defined as a figure for electric savings (25%) compared to the state of the art at competitive (i.e. comparable) cost. Therefore, cost-savings that were achieved for some of the components that were developed were allowed to be compensated by increased cost for other components or increased collector areasin order to show the project's achievements in the light of the defined key performance indicator.At present, the updated simulations show electric savings of 17%, 24%, 26%, and 30%, respectively, for the different developments and the different target heat loads.Threeof these systems will be built and tested during 2015,using the whole system test method that was further developed within the MacSheep project (see report D2.3 for more details). The results from these tests will give benchmark energy used of these systems both for the test sequence itself but also on an annual base. In addition, the simulation models described in this report will be verified against the measurements and then used for annual simulations for otherboundary conditionsthan the once that are represented in the test sequence.

  • 6.
    Bales, Chris
    et al.
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Betak, Jan
    Broum, Michal
    Chèze, David
    CEA INES.
    Cuvillier, Guillaume
    Haberl, Robert
    Institut für Solartechnik SPF Hochschule für Technik HSR.
    Haller, Michel Y.
    Institut für Solartechnik SPF Hochschule für Technik HSR.
    Hamp, Quirin
    Poppi, Stefano
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Weidinger, Alexander
    Final report on storage developments in WP - Deliverable 5.4: MacSheep - New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance2015Rapport (Övrig (populärvetenskap, debatt, mm))
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  • 7.
    Baranger, Renaud
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Performance Analysis of a Grid-Connected PV System in Borlänge, Sweden2014Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This thesis aimed to evaluate the performance of the new configuration of the array one of Högskolan Dalarna grid-connected PV system. This PV grid-connected system has been in operation since 1994. The system is composed of two arrays with a rated power of 1.62kW and two inverters of 1.2 kWp. In 2014 the new configuration of array one was composed of 4 strings of 9 modules each. This configuration had twice as much current than array two, and its voltage was halved (180V). The objective was to improve the global performance of the system, mostly under low irradiance conditions. The performance evaluation of the system was conducted according to IEC 61724 standard, and was performed in March and April 2014.

    It appeared that the higher current in array one improved the turn-on power of its inverter. While the inverter of array two started operating at 126W/m² the inverter of array one started at 37W/m². It was also shown that the array yield of array one increased by 1% at low irradiance (0-200W/m²) during the two months of this thesis work. Moreover, the input voltage dependency of the inverter was clearly shown. Halved the voltage in array one increased the inverter efficiency between 1% and 2%. It was shown that the higher current of the array one did not impact the losses of the system. The system losses also decreased between 9.4% and 10.5%. Besides, this work highlighted that arrays’ DC power was probably different. It led to a better performance of array two at high irradiance compare to array one. Eventually the performance ratio of array one was greater than array two during these two months. It reached 63.2% in March and 69.4% in April.

  • 8.
    Bastholm, Caroline
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik. IEA Photovoltaic Power Systems Programme.
    A user guide to simple monitoring and sustainable operation of PV-diesel hybrid systems: Handbook for system users and operators2015Rapport (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    This report contains a suggestion for a simple monitoring and evaluation guideline for PV-diesel hybrid systems. It offers system users a way to better understand if their system is operated in a way that will make it last for a long time. It also gives suggestions on how to act if there are signs of unfavourable use or failure. The application of the guide requires little technical equipment, but daily manual measurements. For the most part, it can be managed by pen and paper, by people with no earlier experience of power systems.The guide is structured and expressed in a way that targets PV-diesel hybrid system users with no, or limited, earlier experience of power engineering. It is less detailed in terms of motivations for certain choices and limitations, but rich in details concerning calculations, evaluation procedures and maintenance routines. A more scientific description of the guide can be found in a related journal article.

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  • 9.
    Bastholm, Caroline
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Using locally available components and local knowledge to build sustainable stand-alone power systems2013Ingår i: Symposium Small PV-Applications : rural electrification and commercial use ; Ulm, Germany, June 17th/18th, 2013, Regensburg: Ostbayerisches Technologie-Transfer-Institut eV (OTTI) , 2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    The aim of this paper is to point out benefits as well as disadvantages associated with the use of locally available, not necessarily standardized, components in stand-alone electrical power systems at rural locations. Advantages and challenges arising when the direct involvement in design, construction and maintenance of the power system is reserved to people based in the area of implementation are discussed. The presented research is centered around one particular PV-diesel hybrid system in Tanzania; a case study in which technical and social aspects related to the particular power system are studied.

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  • 10. Bee, Elena
    et al.
    Prada, Alessandro
    Baggio, Paolo
    Psimopoulos, Emmanouil
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik. Uppsala University.
    Air-source heat pump and photovoltaic systems for residential heating and cooling: Potential of self-consumption in different European climates2019Ingår i: Building Simulation, ISSN 1996-3599, E-ISSN 1996-8744, Vol. 12, nr 3, s. 453-463Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Renewable sources will play a key role in meeting the EU targets for 2030. The combined use of an aerothermal source through a heat pump and a solar source with a photovoltaic (PV) system is one feasible and promising technology for the heating and cooling of residential spaces. In this study, a detailed model of a single-family house with an air-source heat pump and a PV system is developed with the TRNSYS simulation software. Yearly simulations are run for two types of buildings and nine European climates, for both heating and cooling (where needed), in order to have an overview of the system behaviour, which is deeply influenced by the climate. The storage system (electrical and thermal) is also investigated, by means of multiple simulation scenarios, with and without the battery and with different water storage sizes. The numerical results provide an overview of the performance of the considered heating and cooling system, as well as the balance of the electrical energy exchange between the grid, the building, and the PV array.

  • 11. Belleri, Annamaria
    et al.
    Zhang, Xingxing
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Saini, Puneet
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Sanchez de soria, Tomas
    Solarwall.
    Paolo, Bonato
    EURAC.
    Adami, Jennifer
    D4.2 Solar assisted ventilation2020Rapport (Övrigt vetenskapligt)
  • 12.
    Bhagat, Rohit Jayprakash
    Högskolan Dalarna, Institutionen för information och teknik.
    Investigation of different factors’impacts on the Peer-to-Peer solarpower sharing potential2021Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Recent years the world has witnessed solar energy gaining popularity, as everyone is inpursuit of a more sustainable form of energy. However, the transition to solar energy hasbeen slow, short term oriented and consumers fail to see the long-term advantages ofswitching to green solutions. Peer-to-peer (P2P) energy sharing solutions are expected tobe the future of solar sector. It is ingenious as it enables cheaper and more efficient powersharing within the community at all hours of the day.The thesis aimed to investigate the impacts of different factors on the P2P solar powersharing performances, including the climate conditions (locations), Photovoltaic (PV)capacity ratio, and energy storage integration. In order to study the impact of differentclimate conditions on energy sharing, three locations are selected, namely, Sweden(Stockholm), Italy (Rome), and India (Bengaluru). For studying the impacts of PV capacityratios and energy storage integration on the power sharing performances, theperformances under a set of different PV capacity ratios and energy storage capacities arestudied.Five basic steps are followed in order to perform the above-mentioned studies. First, theconfiguration of the design alternatives is properly selected, and a 3D model is developedin a format that can be imported into a simulation software. Second, the electricity load iscalculated for a group of single-family houses and apartment buildings considering theelectricity devices such as lighting, cooking, refrigerator, washer, dryer etc. Similarly, forcommercial buildings, electricity load is calculated by considering daily energy demand forservers, computers, and lighting. Third, the simulation software is used to perform theestimation of renewable energy production. The simulation software requires inputs suchas PV area, surrounding area, weather data file and load profile. The output is the hourlyPV production and economic analysis. The fourth step is to evaluate the potential forpower-sharing in different communities by using the obtained building electricity load andpower supply data. The impacts of different factors are analysed and discussed in the laststep of this study. The result is in the form of how much amount of power can be sharedin the community considering the various factors mentioned above.The result of the study shows that more power can be shared if a community has a higherpercentage of PV. A small percentage of PV is unable to achieve the maximum amount ofpower sharing. In the case of energy storage, with the increase of battery capacity, powersharing will increase and gradually reach a saturation point. After the saturation point, theincrease in battery storage will not lead to any rise in power sharing. Summarizing thescientific contribution of this study can help urban designers or engineers to design or planpower sharing building community in the future. Also, empowers prosumers andconsumers, leading to increased renewable energy deployment and flexibility in the grid.

  • 13.
    Binder, Betty
    et al.
    Högskolan Dalarna.
    Espensen, Torben
    Rantil, Michael
    Hultmark, Göran
    Nordström, Christer
    Båve, Eric
    Solvärme i bebyggelse: solenergiseminarium i Borlänge 18/8 19891989Rapport (Övrigt vetenskapligt)
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  • 14. Birchall, Sarah
    et al.
    Gustafsson, Marcus
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik. KTH.
    Wallis, Ian
    Dipasquale, Chiara
    Bellini, Alessandro
    Fedrizzi, Roberto
    Survery and simulation of energy use in the European building stock2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    the work towards increased energy efficiency. In order to plan and perform effective energy renovation of the buildings, it is necessary to have adequate information on the current status of the buildings in terms of architectural features and energy needs. Unfortunately, the official statistics do not include all of the needed information for the whole building stock.

     

    This paper aims to fill the gaps in the statistics by gathering data from studies, projects and national energy agencies, and by calibrating TRNSYS models against the existing data to complete missing energy demand data, for countries with similar climate, through simulation. The survey was limited to residential and office buildings in the EU member states (before July 2013). This work was carried out as part of the EU FP7 project iNSPiRe.

     

    The building stock survey revealed over 70% of the residential and office floor area is concentrated in the six most populated countries. The total energy consumption in the residential sector is 14 times that of the office sector. In the residential sector, single family houses represent 60% of the heated floor area, albeit with different share in the different countries, indicating that retrofit solutions cannot be focused only on multi-family houses.

     

    The simulation results indicate that residential buildings in central and southern European countries are not always heated to 20 °C, but are kept at a lower temperature during at least part of the day. Improving the energy performance of these houses through renovation could allow the occupants to increase the room temperature and improve their thermal comfort, even though the potential for energy savings would then be reduced.

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  • 15.
    Board, Anthony
    Högskolan Dalarna, Institutionen för information och teknik.
    Design and control of EV based peer-to-peer energy sharing framework for improving energy performances of building communities2023Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Electric vehicles, which have both energy storage capability and mobility capability, can provide a new solution for electricity sharing between different building communities (i.e., a group of buildings connected with a microgrid). This comes to the community-to-community (C2C) energy sharing network. The C2C energy sharing networks have the potential to not only minimize the effects of electric vehicle integration into the energy grid, but also improve the electricity grid efficiency as a whole. In this thesis, a coordinated smart charging method of electric vehicles (EVs) is proposed for the C2C model. The proposed method considers the power regulation needs in both the present parking community and the next destination community. Then, based on the needs of both communities, the control method will decide the optimal amount of electricity that can be delivered by EV, so that the energy performances in both communities can be the best. The developed coordinated control has been compared with a base case (without any smart charging) and an uncoordinated control case under two control strategies: minimizing the peak energy exchanges with the grid and maximizing the renewable self-utilization. The genetic algorithm tools in MATLAB software are used for the optimization of the model. Meanwhile, to test the robustness of this C2C model, different combinations of building communities have been studied, namely residential-workplace, residential-university, and residential-workshop communities. The case study reveals that the C2C model is effective in improving energy performance under both control strategies. Peak reduction control strategies work most effectively for smaller systems with lower electricity demand and production. With C2C energy sharing, the annual mean peak reduction ranged from 39 % at the smallest community and 20 % at the largest community. Self-consumption maximization strategies work best for systems with a larger surplus of electricity production. With C2C energy sharing, the annual self-consumption increase ranged from 50 % at the community with the largest production surplus, to 7 % at the community with the smallest production surplus. The residential-workshop community studied in this thesis benefited the most from C2C charging control due to its production surplus and the relatively low electricity demands of the communities.

     

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  • 16.
    Brandsma, Age
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Performance Evaluation for a Solar Assisted Air Conditioning System in Taipei2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This report shows the study performed at Taipei National University of Technology in Taipei to evaluate the performance of a solar air conditioning system. The performance is evaluated under Taiwan climate conditions. The research is performed under summer weather conditions. No influence is done on these conditions. A solar air conditioning system currently available on the market is used. No changes are made to the system.

    The work to be done is divided into different phases in order to guide the process. First, a literature research is done to find similar research done on this topic and to gain a basic understanding of the topic. Then several measurement plans are made to investigate different parts of the system.. Measurements are done. It is tried to developing a computer model in order to be able to simulate the system performance.

    The overall objective was to gain knowledge about a solar assisted air-conditioning system and develop a model to simulate the system. Initially a list of research questions was made in order to quantify ‘gaining knowledge’ about the system. The plan was to answer them by using measurement data and creating a model to perform simulations. There are measurements done in this report, however due to too many ‘unknowns’* it is difficult to draw conclusions from them. A lot of research questions are still open and they are also not included in this report. It is also not succeeded to make a working model of a solar assisted air conditioner.

    It is succeeded in making a model to predict the performance of the evaporator. This model is currently within 11% accurate.

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  • 17. Broman, Arne
    et al.
    Broman, Lars
    Högskolan Dalarna.
    A sun cell cornet unfolded1985Rapport (Övrigt vetenskapligt)
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    fulltext
  • 18.
    Broman, Lars
    Högskolan Dalarna.
    Forskningsprogram 1/7 1987 - 30/6 19901987Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 19.
    Broman, Lars
    Högskolan Dalarna.
    On a possible international network for solar energy education1989Rapport (Övrigt vetenskapligt)
  • 20.
    Broman, Lars
    Högskolan Dalarna.
    Progress report 1984-851984Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 21.
    Broman, Lars
    Högskolan Dalarna.
    Progress report 1986-871986Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 22.
    Broman, Lars
    Högskolan Dalarna.
    SERC progress report 1988-891989Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 23.
    Broman, Lars
    Högskolan Dalarna.
    Solenergi i Gambia1987Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 24.
    Broman, Lars
    Högskolan Dalarna.
    Solenergi i Irak, Indien och Libyen: Korta rapporter från konferenser och studieresor 19881989Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 25.
    Broman, Lars
    et al.
    Högskolan Dalarna.
    Broman, Arne
    A paraboloid reflector approximated by simple surfaces1985Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 26.
    Broman, Lars
    et al.
    Högskolan Dalarna.
    Broman, Arne
    Rapport från / Report from International conference applied optics in solar energy Prag/Prauge July 7-9 19871988Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 27.
    Broman, Lars
    et al.
    Högskolan Dalarna.
    Börjesson, Kent
    Högskolan Dalarna.
    Nordlander, Svante
    Högskolan Dalarna.
    Rönnelid, Mats
    Högskolan Dalarna.
    Rapport från / Report from ISES solar world congress Hamburg September 13-18 19871988Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 28.
    Broman, Lars
    et al.
    Högskolan Dalarna.
    Figueroa, Eduardo
    Isaksson, Per
    Nordlander, Svante
    Högskolan Dalarna.
    Rönnelid, Mats
    Högskolan Dalarna.
    Workshop on PRESIM: a graphical preprocessor for modular simulation programs e.g. TRNSYS1988Rapport (Övrigt vetenskapligt)
  • 29.
    Broman, Lars
    et al.
    Högskolan Dalarna.
    Lindberg, Eva
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Reflection losses from cylindrical concave absorber glazings and PV module surfaces1989Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    FULLTEXT01
  • 30.
    Broman, Lars
    et al.
    Högskolan Dalarna.
    Nordlander, Svante
    Högskolan Dalarna.
    New Swedish simulation and design tool for solar heating systems: a preliminary study1987Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 31.
    Broman, Lars
    et al.
    Högskolan Dalarna.
    Nordlander, Svante
    Högskolan Dalarna.
    Rönnelid, Mats
    Högskolan Dalarna.
    Solstrutar för koncentration av solljus mot solceller1987Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 32.
    Brüstle, Florian
    Högskolan Dalarna, Institutionen för information och teknik.
    Carbon footprint optimization for a large-scale PV on-grid System in Borlänge, Sweden2022Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The aim of this master thesis is to design and analyze a photovoltaic (PV) system with the smallest possible carbon footprint. The system will be located in Borlänge, Sweden near the airport. The main components the analysis will focus on are the modules, inverters as well as the cabling. For that, different technologies like thin film and crystalline silicon cells will be compared with each other in order to find out how much the energy consumption in production differs. Since carbon emissions depend on the electricity mix, the manufacturer will also be included in the analysis. That way, manufacturers that use highproportions of renewable energies can produce products with a small carbon footprint, even if the energy demand is comparatively high. The last phase, will focus on factors such as warranties, because longer lifetimes also help to reduce the carbon footprint.

    For the analysis two software are used. The Granta EduPack, which has data on the carbon emissions for different materials and therefore is used to estimate carbon footprints for some of the components. As well as PVsyst, a software to simulate PV projects. It is used to scale the components and also to get an estimate for the annual yield and its deviation.

    The analysis finds that even in Sweden, a carbon footprint (CF) of just 14 g/kWh can be achieved. This value is 70 percent below that of today's average utility scale PV system. Considering the margin of error, it is assumed that this value could be as low as 11 g/kWh under optimal conditions and up to 23 g/kWh in the worst case. This puts the CF in the same range as on- and offshore wind power. For better suited locations such as near the equator, this value could be more than halved.

    With these values, PV is already one of the lowest emitters of greenhouse gases (GHG) among power generation technologies. It can be assumed that these values will continue to fall. Due to process optimization and an increase in efficiency, the carbon footprint of both modules and inverters is reducing steadily.

    This thesis is written in cooperation with two Energy Efficient Built Environment (EEBE) students, who in addition analyze the mounting structure of the system. The aim for the mounting structure is to have a low carbon footprint as well. Their results on the different structural materials are integrated in the conclusion.

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  • 33.
    Burke, Camille
    et al.
    Högskolan Dalarna, Institutionen för information och teknik.
    Torres Riera, Torres
    Högskolan Dalarna, Institutionen för information och teknik.
    Economic and technical feasibilityto integrate photovoltaics intoelectric vehicle charging: Case study: Self-storage companybuildings in Spain2021Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The purpose of this work is to uncover the potential of the existing building infrastructuresof a storage-unit company with a negligible energy demand to utilize its roof area for aphotovoltaic system. Moreover, to use the electricity from PV to power DCFCS installmentsgiven the buildings’ pivotal locations along a highway. This was done by developing a modelin MATLAB capable of simulating the electric vehicle (EV) load distribution for two EVcharging stations (CSs) on the AP-7 highway in Spain. For powering these CSs, a gridconnected photovoltaic (PV) system for each station was designed to support the EVcharging activity. In order to estimate the economic viability of the CSs, an economicevaluation was carried out. It was found that with a battery electric vehicle (BEV) trafficvolume of 18 980 annually, a total of 9281 BEVs were charged in those CSs. The profitabilityof the study was proven, with 64% and 65% profit margins for CS1 and CS2 respectively.In conclusion, the PV production was found to reduce the cost of EV charging with respectto a scenario where there was no PV system. The implications of the study have the potentialto demonstrate an increase in the value of a company by utilizing its location and roof areato incorporate an EV charging station. Furthermore, the model was created so that it can besimulated using different assumptions to evaluate the techno-economic feasibility of any EVcharging system that incorporates PV power production. 

  • 34. Båve, Eric
    et al.
    Broman, Lars
    Högskolan Dalarna.
    Servicebehov och driftserfarenheter av solfångare i småhus: en förstudie1987Rapport (Övrigt vetenskapligt)
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  • 35.
    Börjesson, Kent
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Mikroelektrifiering i Gambia: Reseberättelse 14-29 november 19881989Rapport (Övrigt vetenskapligt)
  • 36. Choudhary, D.
    et al.
    Kaithwas, S.
    Sharma, R. K.
    Mishra, A.
    Singhai, S.
    Powar, Satvasheel
    Högskolan Dalarna, Institutionen för information och teknik, Energiteknik. School of Engineering, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh, India.
    Singh, A.
    Recycling of waste toner derived from exhausted printer cartridges as adsorbent for defluoridation of water2024Ingår i: Environmental Technology & Innovation, ISSN 2352-1864, Vol. 34, artikel-id 103572Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Due to the broad adoption of electronic and electrical equipment and the quick advancement of contemporary innovations in this domain, significant amounts of electronic waste have been produced. This category of waste includes the toner powder used by printers, copiers, and fax machines to print text and images. This paper describes a sustainable and environmentally friendly method of recycling waste toner powder. The chemical composition of this printer cartridge toner (PCt) powder is carbon, Fe3O4, polypropylene (polymeric resin), and SiO2 composite. Toner powder from exhausted printer cartridges was utilized as an adsorbent to remove fluoride from water. It has a fluoride adsorption capacity of 60 mg/g and a specific surface area of 20 m2/g. X-ray diffraction and electron microscopic investigations were used to investigate the chemical composition, structure, and surface morphology of the material. To analyze the collected experimental data, the Freundlich and Langmuir adsorption isotherm models were used. Time-dependent kinetic experiments were conducted to determine the mechanism of the adsorption process using pseudo-first-order kinetics, pseudo-second-order kinetics, and intraparticle diffusion kinetic models. The fluoride adsorption process was shown to be feasible and spontaneous (ΔG < 0) based on calculated thermodynamic characteristics, which included enthalpy, Gibbs free energy, entropy (ΔS > 0), and adsorption activation energy. The study also discussed its reusability as an adsorbent and examined its functioning capability in actual water. © 2024 The Authors

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  • 37. Chèze, David
    et al.
    Bales, Chris
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Betak, Jan
    Broum, Michal
    Heier, Johan
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Heinz, Andreas
    Franz, Hengel
    Hamp, Quirin
    Poppi, Stefano
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Final report on Control strategies, fault detection and on-line diagnosis in WP6 - Deliverable 6.4: MacSheep -New Materials and Control for a next generation of compact combined Solar and heat pump systems with boosted energetic and exergetic performance2015Rapport (Övrig (populärvetenskap, debatt, mm))
    Abstract [en]

    The main objective of this work package was to investigate generic control strategies, generic fault-detection and on-line diagnosis algorithms that may apply to the developed prototypes of solar and heatpump systems within MacSheep. The results should lead toimproved reliability and/orincreased energy savings for the end-userthrough new controller features. The use of DHW consumption forecast was identified as a promising control strategy and a simple yet reasonably effective algorithm to get the water tapping behaviourof the userwas developed. Viessmannimplemented the ideas of this approach in an ICT solution for their controller to provide statistical tapping informationto the user who can then set the period when hot waterthatis expected to be used. The operationalstrategy based on DHW consumptionforecast for one hour was not implemented since the potential gains are small (~2%) and there is ahigh user discomfort risk in the case of an inaccurate forecastPrevious studies have shown that solar overheating of the building led to gas savings with solar gas combisystems. Using a similar strategy on the MacSheep reference system did not lead to significant savings, due to strong interactions between space and DHW heating and a higher share of HP operation time for DHW charging of the store, which has a lower efficiency.Another smart control strategy was investigated forvariable electricity pricesusing overheating of the building and/or the DHW volume of the store.The main conclusion of the study is that the combination of the two algorithms led to cost savings for the Austria (Graz) and France (Chambery) with both theSFH45 and SFH100 buildings.Since only the share related to user consumption varies during the day while the grid and transmission costs are usually constant, thecost savings were small, far below 1%.Among the proposed fault detection algorithms for solar and heat pump systems, detection of wrongly connected tubes in the solar collector loop was found interesting by Viesmmann and Regulus. It was implemented and tested in their respective prototype controller. Regulus also implemented the detection of wrong order phase connections in its heat pump prototype as well as threshold tests on abnormal temperature and pressure evolution.

  • 38. Dahlgren, Lars
    et al.
    Börjesson, Kent
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Broman, Lars
    Högskolan Dalarna.
    Solmätstation i Borlänge1989Rapport (Övrigt vetenskapligt)
  • 39. Dalenbäck, Jan-Olof
    et al.
    Josefsson, Weine
    Granqvist, Claes-Göran
    Karlsson, Björn
    Nordell, Bo
    Sigurdh, Dag
    Solenergiteknik: solenergiseminarium i Borlänge 28/8 19881988Rapport (Övrigt vetenskapligt)
  • 40.
    Das, Tanmoy
    Högskolan Dalarna, Institutionen för information och teknik.
    Study and analysis of BIPVsystems to developrecommendation guidelines forBIPV in Sweden2021Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    To achieve a sustainable environment efficient use of energy is paramount. The buildingsector provide a great opportunity in this direction. Integration of photovoltaics (PV) intobuilding skin is an effective way of meeting the energy demand utilizing large unused façadespaces besides the roof space. Building integrated photovoltaics (BIPV) replacesconventional construction products and provide better building functionality like shading,heat gain, maintaining indoor temperature, improving aesthetics while simultaneouslyproducing electricity.The thesis aims to define and classify BIPV systems based on the application area in thebuilding along with their applicable standards and to develop a recommendation guidelinefor the use of these standards and regulations in Sweden. The agenda is to make it easier forstakeholders involved in a project to navigate through these complex standards and refer tothe standards as per their need and requirements.To achieve this, firstly a brief overview of the technology is presented which is followed bythe detailed classification of BIPV application areas. Here the systems are divided betweenroof mounted, façade mounted, and sun screening components and the integrationtechniques are also discussed. The barriers in BIPV implementation are listed andstakeholders are analyzed. The relevant stakeholders who can benefit from the guidelinesare identified (mainly the primary and secondary stakeholders) and the level of influence ofthe guidelines on them versus their interest in the project is compared.The BIPV regulations in Sweden are taken from Boverket’s database and tabulated. Also,requirements for BIPV standards are categorized. Using this information, the general,electrical, and building related requirements for BIPV are listed with applicable standardsfor each application area in the building (A to E). The results are presented separately forstandards applicable for BIPV modules and BIPV systems. The requirement categoryapplicable for desired stakeholders is also presented as part of the result.

  • 41.
    Dermentzis, Georgios
    et al.
    Univeristy of Innsbruck.
    Gustafsson, Marcus
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik. KTH.
    Ochs, Fabian
    Univeristy of Innsbruck.
    Holmberg, Sture
    KTH.
    Feist, Wolfgang
    Passivhaus Institut.
    Calabrese, Toni
    University of Innsbruck.
    Oberrauch, Philipp
    University of Innsbruck.
    Evaluation of a versatile energy auditing tool2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    Energy auditing can be an important contribution for identification and assessment of energy conservation measures (ECMs) in buildings. Numerous tools and software have been developed, with varying degree of precision and complexity and different areas of use.

     

    This paper evaluates PHPP as a versatile, easy-to-use energy auditing tool and gives examples of how it has been compared to a dynamic simulation tool, within the EU-project iNSPiRe. PHPP is a monthly balance energy calculation tool based on EN13790. It is intended for assisting the design of Passive Houses and energy renovation projects and as guidance in the choice of appropriate ECMs.

     

    PHPP was compared against the transient simulation software TRNSYS for a single family house and a multi-family house. It should be mentioned that dynamic building simulations might strongly depend on the model assumptions and simplifications compared to reality, such as ideal heating or real heat emission system. Setting common boundary conditions for both PHPP and TRNSYS, the ideal heating and cooling loads and demands were compared on monthly and annual basis for seven European locations and buildings with different floor area, S/V ratio, U-values and glazed area of the external walls.

     

    The results show that PHPP can be used to assess the heating demand of single-zone buildings and the reduction of heating demand with ECMs with good precision. The estimation of cooling demand is also acceptable if an appropriate shading factor is applied in PHPP. In general, PHPP intentionally overestimates heating and cooling loads, to be on the safe side for system sizing. Overall, the agreement with TRNSYS is better in cases with higher quality of the envelope as in cold climates and for good energy standards. As an energy auditing tool intended for pre-design it is a good, versatile and easy-to-use alternative to more complex simulation tools.

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  • 42.
    Duhoranimana, Olivier
    Högskolan Dalarna, Institutionen för information och teknik.
    Investigation of Solar Powered EV Charging StationPotential2021Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    The worldwide fast growth of the transportation sector contributes to a large andgrowing share of global greenhouse gas (GHG) emissions. The Swedish TransportAdministration report indicates that emissions from domestic transport increasedin 2018. Having an idea that the workplace parking lots have the potential toincrease the share of renewable energy production in Sweden, an investigation forthe solar-powered electric vehicle (EV) charging station is conducted. This studyaims to clarify the knowledge on what the potentials are, financial assessment, andassessment of the photovoltaic (PV) self-consumption of EV charging in theworkplace charging station. Without knowledge about the highlighted parameters,investors may hesitate to invest in a PV project such as a solar-powered EV chargingstation system. To achieve the objective of this thesis, appropriate tools and/orsoftware are used. PV*SOL software tool is used for simulation and analysis ofenergy system efficiency with EV charging station integrated for different PVsystems deployed in the same location of Sweden. This software tool allows thedesign and calculations of the PV system and EV charging station integrated.Currently registered cars in Sweden indicate that EVs are dominating and will keepthe pulse in the future. This domination will enforce more need for electricity, callfor renewable energy use, and promising significant GHG emissions reduction –sustainable environment. The study has proven that there is no immense insolationin Sweden, thus, the power converter can be undersized up to 30 % with respect tothe PV array to reduced energy loss. A feasible solar-powered EV charging stationrequires several factors such as initial investment (EV charging station, PV module,inverter, transport and installation, operation, and maintenance, etc.), andelectricity trading rate. The study of five PV system cases showed that the increasein size significantly increases the self-sufficiency ratio while self-consumption ratiodecreases. By increasing the PV array, both levelized cost of electricity and paybackperiod were considerably decreased as was intended. However, the more PV arrayincreased in size the more initial investment is required. Study on GHG emissionsof the solar-powered EV charging station as well as the deployment of local energystorage and EV smart charging are recommended as future works.

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  • 43.
    El Kontar, Nabil
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Optimization of Grid-Connection Capacity for Wind Power Plants by Adding Photovoltaic Power2014Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    A wind farm does not operate at nominal power output all the time around the year due to the intermittent nature of the wind and thus leaving a chance to further utilize the transformer rating by adding another power generation. Since the necessary infrastructure for grid connection has been already laid out for the wind farm, adding a certain capacity of photovoltaic power to the low voltage side of the transformer offers a potential to optimize the power production of the hybrid plant at a reduced initial investment. In this thesis, the study aims to optimize the power production of a grid connected wind farm by adding photovoltaic panels. The studied wind farm, located in Gotland Island in southern Sweden, contains three wind turbines with a nominal capacity of 150 kW each; totaling to 450 kW of wind power and coupled to the grid by a utility owned transformer of 500 kVA capacity. Total power production resulting from the addition of a certain photovoltaic power is analyzed on hourly basis in order to keep it below transformer’s rating. A total power production exceeding 500 kW will result in an overload and is reduced to 500 kW thus resulting in losses. Hourly wind power production data was provided by the operator for a period of one year, and solar irradiance data for the same year was obtained from SMHI “Swedish Meteorological and Hydrological Institute” for Gotland isle. The power production from a specified photovoltaic module was simulated for different photovoltaic capacities at different tilt angles and the estimated total generated power was analyzed with an aim to add as much photovoltaic power while keeping overloads to a minimum. In this studied case, the utility company owning the transformer requested that the maximum allowed power should be 450 kW (50 kW below the nominal rating) although previously the wind farm was allowed to deliver up to 550 kW active power. It is shown that the amount of photovoltaic power that can be added, while keeping lost power due to overloads at a minimum of 1% of total generated power, is highly dependent on transformer rating. The transformer rating of 450 kW 500 kW and 550 kW resulted in potential photovoltaic peak power of 125 kWp 325 kWp and 425 kWp respectively to be added. Optimizing the added photovoltaic power in a way to minimize total power standard deviation on yearly basis (series of twelve months) results in a recommended peak capacity of 500 kWp or 110% of the rated wind power, while a suitable transformer will be rated at 700 kVA.

  • 44. Enqvist, Ingvar
    et al.
    Wilson, Gunnar
    Grellsgård, Bengt
    Isakson, Per
    Jilar, Torbjörn
    Karlsson, Björn
    Solvärme i fjällvärme och gruppcentraler: Solenergiseminarium i Borlänge 17/8 19891989Rapport (Övrigt vetenskapligt)
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    FULLTEXT01
  • 45. Eriksson, Olle
    et al.
    Widegren, Karin
    Andersson, Hans E. B.
    Hultmark, Göran
    Isakson, Per
    Kaiser, Arne
    Solenergins framtid i Sverige: solenergiseminarium i Borlänge 26/8 19881988Rapport (Övrigt vetenskapligt)
    Ladda ner fulltext (pdf)
    fulltext
  • 46.
    Fiedler, Frank
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    A testing and demonstration facility for PV systems and components2013Ingår i: Proceedings of 3rd Symposium Small PV Applications: Rural Electrification and commercial use / [ed] OTTI e.V., Regensburg, Germany, 2013, s. 111-116Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    A test and demonstration facility for PV and PV hybrid systems and system components has been designed and installed at Dalarna University in Sweden. The facility allows studies of complete PV systems or single components in a range of 0.1-10 kW. The facility includes two grid-connected PV systems, a PV Hybrid off-grid system, three emulators and the necessary measurement and control equipment. Tests can be done manually or automatically through programmed test procedures controlled that will be implemented in Labview. The facility shall be used by researchers, professionals of the industry and engineering students.

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  • 47.
    Fiedler, Frank
    et al.
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Persson, Tomas
    Högskolan Dalarna, Akademin Industri och samhälle, Energi och miljöteknik.
    Carbon monoxide emissions of combined pellet and solar heating systems2009Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, nr 2, s. 135-143Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Emissions are an important aspect of a pellet heating system. Low harmful emissions, particularly carbon monoxide, are a measure of a well performing system. High carbon monoxide emissions are often caused by unnecessary cycling of the burner and when the average load is below the lowest possible combustion power of the burner. Combining pellet heaters with a solar heating system can significantly reduce cycling of the pellet heater and avoid the inefficient summer operation of the pellet heater. Five combined systems representing the range of typical solutions of this system type and one recently developed system have been studied, modelled and simulated. These systems are compared to a reference system, which is based on a pellet boiler and is not combined with a solar heating system. The aim was to study CO-emissions of the different types of systems and to analyse the potential of CO-emission reduction when the pellet heater is combined with a solar heating systems. Another aim was to compare the yearly CO-emissions obtained from simulations under realistic dynamic conditions with the yearly CO-emissions calculated based on the values that are obtained by the standard test methods. The study was performed with the simulation tool TRNSYS. The parameter used in the study have been identified from lab measurements on existing pellet boilers/stoves and solar heating systems. The results from the simulations show that it is possible to almost halve the CO-emission if the pellet heater is combined with a solar heating system. The results also show that the CO-emission of existing combined solar and pellet heating systems can be drastically reduced if the pellet heater is properly controlled and some basic design rules are observed. This can also be seen when analyzing the results for the new system concept where these rules have been taken into account. Comparing the yearly CO-emissions obtained from the simulations with the yearly CO-emissions calculated based on the standard test methods shows that using the latter give too low CO-values for the whole year. It is also shown that for the existing systems the average emissions under these realistic annual conditions were greater than the limit values of two Eco-labels.

  • 48.
    Filatov, Artem
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Concentrating Collector for Torsång District Heating System2018Självständigt arbete på avancerad nivå (masterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In this thesis report for Dalarna University in Borlange and Absolicon company the study of a possibility to add an array of concentrating solar collectors to a Torsång district heating system was done. The whole idea of this work was to make a simulation of this kind of system, trying to get 15-20% of solar fraction, and make an economical evaluation.

    At the same time, another goal was to make two comparisons: between concentrating and flat-plate collector in the same system, and between two tools for collector analysis – Polysun and Absolicon tool, based on TRNSYS, which was designed to estimate the output of the collector for a certain temperature, without any load.

    During the study, the analysis of the simulating tools was made and the combination of those two tools was used. Using long iteration cycles, involving changing the field layout, number of collectors and distance between collector rows in flat-plate collector case, both types of collectors were analyzed. The method of the analysis was to get an equal output of the field and see the differences, which appear while using different collector types.

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  • 49. Gorjian, Shiva
    et al.
    Calise, Francesco
    Kant, Karunesh
    Ahamed, Md Shamim
    Copertaro, Benedetta
    Högskolan Dalarna, Institutionen för information och teknik, Energiteknik.
    Najafi, Gholamhassan
    Zhang, Xingxing
    Högskolan Dalarna, Institutionen för information och teknik, Energiteknik.
    Aghaei, Mohammadreza
    Shamshiri, Redmond R.
    A review on opportunities for implementation of solar energy technologies in agricultural greenhouses2021Ingår i: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 285, artikel-id 124807Artikel i tidskrift (Refereegranskat)
  • 50. Gu, Yaxiu
    et al.
    Zhang, Xingxing
    Högskolan Dalarna, Akademin Industri och samhälle, Energiteknik.
    Myhren, Jonn Are
    Högskolan Dalarna, Akademin Industri och samhälle, Byggteknik.
    Han, Mengjie
    Högskolan Dalarna, Akademin Industri och samhälle, Mikrodataanalys.
    Chen, Xiangjie
    Yuan, Yanping
    Techno-economic analysis of a solar photovoltaic/thermal (PV/T) concentrator for building application in Sweden using Monte Carlo method2018Ingår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 165, s. 8-24Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The solar energy share in Sweden will grow up significantly in next a few decades. Such transition offers not only great opportunity but also uncertainties for the emerging solar photovoltaic/thermal (PV/T) technologies. This paper therefore aims to conduct a techno-economic evaluation of a reference solar PV/T concentrator in Sweden for building application. An analytical model is developed based on the combinations of Monte Carlo simulation techniques and multi energy-balance/financial equations, which takes into account of the integrated uncertainties and risks of various variables. In the model, 11 essential input variables, i.e. average daily solar irradiance, electrical/thermal efficiency, prices of electricity/heating, operation &amp; management (OM) cost, PV/T capital cost, debt to equity ratio, interest rate, discount rate, and inflation rate, are considered, while the economic evaluation metrics, such as levelized cost of energy (LCOE), net present value (NPV), and payback period (PP), are primarily assessed. According to the analytical results, the mean values of LCOE, NPV and PP of the reference PV/T connector are observed at 1.27 SEK/kW h (0.127 €/kW h), 18,812.55 SEK (1881.255 €) and 10 years during its 25 years lifespan, given the project size at 10.37 m2 and capital cost at 4482–5378 SEK/m2 (448.2–537.8 €/m2). The positive NPV indicates that the investment on the selected PV/T concentrator will be profitable as the projected earnings exceeds the anticipated costs, depending on the NPV decision rule. The sensitivity analysis and the parametric study illustrate that the economic performance of the reference PV/T concentrator in Sweden is mostly proportional to solar irradiance, debt to equity ratio and heating price, but disproportionate to capital cost and discount rate. Together with additional market analysis of PV/T technologies in Sweden, it is expected that this paper could clarify the economic situation of PV/T technologies in Sweden and provide a useful model for their further investment decisions, in order to achieve sustainable and low-carbon economics, with an expanded quantitative discussion of the real economic or policy scenarios that may lead to those outcomes.

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