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  • 1.
    Abdel Rahman, Assem
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Electrical Evaluation of a Low Concentrating PVT Collector Based on Performance Ratio2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Photovoltaic Thermal/Hybrid collectors are an emerging technology that combines PV

    and solar thermal collectors by producing heat and electricity simultaneously. In this paper,

    the electrical performance evaluation of a low concentrating PVT collector was done

    through two testing parts: power comparison and performance ratio testing. For the

    performance ratio testing, it is required to identify and measure the factors affecting the

    performance ratio on a low concentrating PVT collector. Factors such as PV cell

    configuration, collector acceptance angle, flow rate, tracking the sun, temperature

    dependence and diffuse to irradiance ratio.

    Solarus low concentrating PVT collector V12 was tested at Dalarna University in Sweden

    using the electrical equipment at the solar laboratory. The PV testing has showed

    differences between the two receivers. Back2 was producing 1.8 energy output more than

    Back1 throughout the day. Front1 and Front2 were almost the same output performance.

    Performance tests showed that the cell configuration for Receiver2 with cells grouping (6-

    32-32-6) has proved to have a better performance ratio when to it comes to minimizing

    the shading effect leading to more output power throughout the day because of lowering

    the mismatch losses. Different factors were measured and presented in this thesis in

    chapter 5.

    With the current design, it has been obtained a peak power at STC of 107W per receiver.

    The solar cells have an electrical efficiency of approximately 19% while the maximum

    measured electrical efficiency for the collector was approximately 18 % per active cell area,

    in addition to a temperature coefficient of -0.53%/ ˚C. Finally a recommendation was

    done to help Solarus AB to know how much the electrical performance is affected during

    variable ambient condition and be able to use the results for analyzing and introducing

    new modification if needed.

  • 2. Albaric, Michael
    et al.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Drueck, Harald
    Gagnepain, B.
    Kuhness, G.
    Letz, T.
    Mette, B.
    Thür, A.
    Nielsen, J.E.
    Papillon, P.
    Solar CombiSystems Promotion and Standardisation (COMBISOL project)2008In: Eurosun 2008, Lisbon, 2008Conference paper (Other academic)
    Abstract [en]

    Solar combisystems (SCS) are solar heating installations providing space heating as well as domestic hot water in buildings. Within a global solar thermal energy strategy, SCS are a key element to decrease the fossil energy demand for heating in existing and new buildings. This project will help to reduce the use of fossil fuels and hence also the emission of greenhouse gases. During 3 years December 2007 – December 2010), experts from research, testing institutes and industry will work in the aim to encourage an accelerated deployment of SCS market – hence a higher share of heat produced by solar energy - and promote an improved quality of the installed systems.

  • 3. Andrén, Lars
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Lennermo, Gunnar
    Handbok för kombinerade sol- och biovärmesystem: Teknik - System - Ekonomi2012Report (Other academic)
    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.

  • 4.
    Angantyr, Anders
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Lågenergibyggande i Dalarna mars 20122012Report (Other academic)
    Abstract [sv]

    Inom ramen för projektet Energi- och miljökompetenscentrum vid Högskolan Dalarna har en kortare studie av lågenergibyggande i Dalarna gjorts. Syftet med rapporten är att ge en sammanställning av det aktuella läget på området i Dalarna.

    Det finns idag ett flertal bygginitiativ, både privata och allmännyttiga, i Dalarna där man ansträngt sig när det gäller energihushållning. En handfull av dessa kommer nog att uppfylla passivhuskraven enligt FEBY, exakt hur många går dock inte att säga pga infomationsbrist och med tanke på osäkerheten i energiberäkningarna.

    En annan slutsats är att medvetenheten om lågenergibyggande på kommunal och allmännyttig nivå är i allmänhet god och att energihushållning är ett område som ges stort fokus vid den nybyggnation som sker.

    När det gäller det privata byggandet av villor så sker det mesta av byggandet enligt hustillverkarnas typspecifikationer. Då tak, grund och ventilationssystem oftast i princip är samma som för passivhus kan det konstateras att egentligen ganska små förändringar i konstruktion och utförande av detta byggande skulle kunna ge hus enligt FEBYs passivhuskrav eller åtminstone minienergihuskrav.

  • 5.
    Angantyr, Anders
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Trätorn: Kan det vara något för svensk vindkraft i skogsmiljö?2011Report (Other academic)
    Abstract [sv]

    Inom ramen för projektet Energi- och miljökompetenscentrum vid Högskolan Dalarna har en kortare förstudie kring tekniken som används av Timber Tower GmbH för höga vindkrafttorn i trä gjorts. Huvudsyftet med studien har varit att titta närmare på tekniken och dess potential för svensk landbaserad vindkraft samt utreda vad detta kan innebära för regionen. Trenden för landbaserad vindkraft i skogsmiljö går mot allt högre torn. Skogsmiljön gör att den marknära turbulensen och vindgradienten blir större än över t.ex. hav vilket gör det mer föredelaktigt att använda högre torn. Tekniken som Timber Tower GmbH använder är att bygga tornet på plats med en konisk hålstomme av plana paneler av korslimmat limträ (som annars främst används vid byggnation av höga hus med massivträstomme). Tekniken är skyddad av ett flertal patentansökningar varav minst en är beviljad. Vid en jämförelse mellan trätorn och svetsade ståltorn (som är den dominerande torntekniken idag) kan det konstateras att trätornstekniken är ekonomiskt intressant. Framförallt blir trätornen mer intressanta i jämförelse med ståltornen vi ökande höjder (> 100 m) pga. dess transportfördelar. Vidare bör det nämnas att de torntekniker som används idag vid höjder runt 140 m och högre främst är fackverkstorn i stål och hybridtorn med en hög bas av förspänd betong och övre delen i stål. Då ett typgodkännande av ett vindkraftverk gäller torn och turbin är det i praktiken alltid turbintillverkaren som prissätter och levererar ett komplett vindkraftverk. Med utgångspunkt i regeringens planeringsram för svensk vindkraftutbyggnad (20 TWh/år landbaserad vindkraft 2020) kan dock marknadsvärdet för torn uppskattas till 2-3 miljarder kr/år fram till 2020. För trätorn motsvarar detta en årlig potentiell volym på ca 190 000 m3. Slutsatsen i denna korta studie är att det är tekniskt möjligt att designa ett trätorn i rimliga dimensioner för en 2-3 MW turbin med navhöjd ca 140 m och att detta sannolikt även är ekonomiskt intressant. Då ett trätorn blir något lättare än motsvarande ståltorn går det åt mindre energi för att göra ett trätorn. Hur mycket mindre är dock osäkert pga. den stora spridningen i siffror för energiåtgång för stålproduktion och i praktiken blir skillnaden även leverantörsberoende. Eftersom andelen förnyelsebar energi är betydligt större vid tillverkningen av materialet för trätornen kommer trätornet att ge en betydande sänkning på utsläppt CO2e/kWhel jämfört med motsvarande verk med ståltorn. Ett annat argument för trätorn är förenklade transporter jämfört med t.ex. svetsade ståltorn eller hybridtorn med prefabricerade betongelement. Om tekniken etableras kan det i förlängningen leda till en regional påverkan i form av ökat lokalt innehåll i vindkraftprojekten t.ex. genom ökade råvaruleveranser (eg. sågat och torkat virke), lokal produktion av korslimmat limträ eller exempelvis bildande av specialiserade montagefirmor. Det största hindret för tekniken just nu är dess marknadsintroduktion och acceptans samt typgodkännande tillsammans med en för svensk marknad intressant turbinleverantör. För att få acceptans för tekniken krävs byggande och utvärdering av minst ett verk med trätorn. En intressant storlek för marknaden är en 2-3 MW turbin med navhöjd ca 140 m. Ett sådant verk skulle i så fall få det högsta vindkrafttornet i Sverige och sannolikt det högsta vindkrafttornet i trä i världen. Byggandet av ett första verk med trätorn skulle sannolikt även kräva ett behov av stödfinansiering för att täcka en projektörs ökade risk. Då flera vindkraftetableringar i regionen uppvisar goda produktionsresultat (med Tavelberget som gott exempel) visar det att regionen är intressant för introduktion och utvärdering av ny teknologi.

  • 6.
    Aprille, Marcello
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Simulation Study of an Innovative Solar Absorption Refrigeration System2006Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The awareness of the environmental problem along with an ever increasing demand for comfort cooling and refrigeration has brought a strong interest in new concepts of refrigeration technologies. By combining solar energy and absorption cooling, solar absorption refrigeration can offer a sound alternative to electrically driven vapour compression refrigeration. In this work, a simulation study of an innovative solar absorption refrigeration system is conducted. The system is intended for refrigeration at 5°C in warm and hot climates (South Europe and North Africa) and is composed of: medium temperature collector, single effect water ammonia absorption chiller and ice-encapsulated cold thermal storage. This configuration is justified by the high temperature difference between the chilled refrigerant temperature, about –5 °C, and the ambient temperature, which could exceed 30 °C. In these conditions, the absorption chiller must be driven by a medium temperature collector. Moreover, the proposed chiller can be air-cooled, thus not making use of a bulky and expensive heat rejection system. Several simulations are conducted in order to investigate the system behaviour at different values of solar fraction and at three different locations: Rome, Tunis and Cairo. Also, two different medium temperature collectors are compared, a Fresnel linear reflector and a parabolic trough. The simulations are made with TRNSYS. User-defined TRNSYS types are made in order to characterise the absorption chiller and the cold thermal storage. The absorption chiller type makes use of performance data made available by the manufacturer and the cold storage type is modelled like a stack of uniform temperature layers of ice capsules surrounded by refrigerant. The mathematical model makes use of experimental equations, derived from literature, in order to represent the heat exchanged between refrigerant and ice capsules during ice to water and water to ice phase transition. The simulations have revealed a strong impact of the adopted control strategy on the system overall performance. Due to limitations in the maximum reachable solar loop fluid temperature, 300 °C, and the minimum reachable refrigerant temperature, -20 °C, two major problems are encountered: chiller part-load functioning, which occurs any time refrigerant temperature approaches –20° C, and loss of available solar radiation, which occurs anytime the collector mirrors are set out of focus in order to maintain the solar loop fluid temperature below 300 ° C. According to the simulation results, with a chiller rate capacity of 13 kW and a load peak power of about 6 kW the system has proved to work with reasonable values of collector area and storage volume at 100% SF and at any of the selected locations. About 70 m2 of Fresnel collector area and 4 m3 of storage tank are necessary to cover the load year round. The parabolic trough would require less area, about 40 m2, but would cost more on the basis of the projected costs of the two solutions. Savings in both solar field area and cold storage volume are possible when using an auxiliary heater series connected to the collector in the solar loop. At 90% solar fraction, the system would require 70% of the collector area and 50% of the storage volume as calculated for 100% solar fraction. A simple economic analysis shows that the here presented concept has a good economical potential when compared to an equivalent PV-electrical vapour compression solution. The overall system performance is higher with a PV based system, due to the high electrical COP of vapour compression chiller. However, the collector-absorption solution is more economical due to the cost of the solar field, which is lower than the cost of PV panels in its PV based counterpart.

  • 7.
    Araujo Lopes, Duarte
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Evaluation of two solar cooling systems (Absorption and Adsorption) in a Commercial Building2008Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    This work presents an experimental study about the influence of operation conditions on the performance parameters of two solar cooling machines, one using adsorption technology (FROST) and the other absorption technology (ROTARTICA). The study was made in cooperation with PROTECMA, an Environmental and Energy Company located at Gijón, Spain. PROTECMA is a business partner of PROFACTOR, an Austrian company which together with CNAM (Conservatoire National des Arts et Métiers) and INDUTHERM Ingeniería e Instalaciones have developed an adsorption chiller prototype (FROST), under the auspices of the research project SOCOLD. FROST is a cost effective small sized (5 kW) solar cooling system for food conservation based on adsorption technology working jointly with a new high temperature (120°C) solar Compound Parabolic Collectors (CPC). ROTARTICA is also a small sized (4.5 kW) solar cooling system for air-conditioning (AC) based on absorption technology. The cooling machines were installed in the commercial building of the Meat Asociación of Asturias, a partnership of PROTECMA, at the village of Noreña, Spain. The thesis includes a state of the art of thermally driven cooling technologies as well as an explanation of the FROST and ROTARTICA technologies. In spite of all the operative limitations imposed to the practical work, it was possible to obtain a few experimental results with FROST machine, which are presented and discussed. Finally, and in accordance with some of the technical problems detected, several tasks for future work developments are proposed.

  • 8.
    Ayadi, Osama
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Measurements, Modelling and Simulations of Thermo Chemical Accumulator used for Solar Cooling2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The demand for cooling and dehumidification of indoor air is growing at a high rate worldwide. Producing cooled air by making use of solar power may seem paradoxical at first sight. However there exist thermal processes to produce coldness, in which water is cooled or air-conditioning is driven directly by a heat input from solar system. The R&D effort to develop solar cooling technologies has increased significantly in the last twenty years. This thesis project is concerned with a new patented small scale solar cooling system, the Thermo Chemical Accumulator (TCA), a technology produced by the Swedish company ClimateWell AB and is available commercially. The work was done both at the Solar Energy Research Centre (SERC) in Borlänge, and at the ClimateWell AB headquarters in Stockholm. In this project, measurements, parameter identification, modelling and parametric study were done in order to develop the Trnsys model of the TCA controller. Measurements established the foundation of the work in this project. It aimed to provide accurate and reliable test data of the performance of the machine that cover the whole range of operating conditions of the machine in reality through a set of well planned and carefully executed experiments. Moreover, two tests were performed to measure the coefficient of performance (COP) of the machine. The previous controller component in Trnsys (Type 214) controls the machine operation relying on the concentration of salt in the machine barrels without taking the operation temperatures into consideration. Obviously this has major drawbacks on the performance of the machine. The new developed controller (Type 216) bases its operation on the temperatures of the machine. A brief parametric study was performed both to ensure that the new developed controller is working properly and to investigate the effect of some operating conditions on the performance of the machine. Results obtained from simulations using the new controller model showed good agreement with measured data. The parametric studies showed that the heat sink temperature has a significant influence on the COP of the machine and that an improvement of the insulation of the machine components could improve the COP of the machine.

  • 9.
    Badri, Seyed Ali Mohammad
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Simulation of Photovoltaic Panel Production as Complement to Ground Source Heat Pump System2013Independent thesis Advanced level (degree of Master (Two Years)), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    This master thesis presents a new technological combination of two environmentally friendly sources of energy in order to provide DHW, and space heating. Solar energy is used for space heating, and DHW production using PV modules which supply direct current directly to electrical heating elements inside a water storage tank. On the other hand a GSHP system as another source of renewable energy provides heat in the water storage tank of the system in order to provide DHW and space heating. These two sources of renewable energy have been combined in this case-study in order to obtain a more efficient system, which will reduce the amount of electricity consumed by the GSHP system.The key aim of this study is to make simulations, and calculations of the amount ofelectrical energy that can be expected to be produced by a certain amount of PV modules that are already assembled on a house in Vantaa, southern Finland. This energy is then intended to be used as a complement to produce hot water in the heating system of the house beside the original GSHP system. Thus the amount of electrical energy purchased from the grid should be reduced and the compressor in the GSHP would need fewer starts which would reduce the heating cost of the GSHP system for space heating and providing hot water.The produced energy by the PV arrays in three different circuits will be charged directly to three electrical heating elements in the water storage tank of the existing system to satisfy the demand of the heating elements. The excess energy can be used to heat the water in the water storage tank to some extent which leads to a reduction of electricity consumption by the different components of the GSHP system.To increase the efficiency of the existing hybrid system, optimization of different PV configurations have been accomplished, and the results are compared. Optimization of the arrays in southern and western walls shows a DC power increase of 298 kWh/year compared with the existing PV configurations. Comparing the results from the optimization of the arrays on the western roof if the intention is to feed AC power to the components of the GSHP system shows a yearly AC power production of 1,646 kWh.This is with the consideration of no overproduction by the PV modules during the summer months. This means the optimized PV systems will be able to cover a larger part of summer demand compared with the existing system.

  • 10.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Combitst-program manual2000Report (Other academic)
  • 11.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    European resarch school on large scale solar thermal - SHINE2014In: Solar District Heating 2014, Hamburg, Germany, 2014Conference paper (Other academic)
    Abstract [en]

    The Solar HeatIntegration NEtwork (SHINE) is a European research school in which 13 PhDstudents in solar thermal technologies are funded by the EU Marie-Curie program.It has five PhD course modules as well as workshops and seminars dedicated to PhDstudents both within the project as well as outside of it. The SHINE researchactivities focus on large solar heating systems and new applications: ondistrict heating, industrial processes and new storage systems. The scope ofthis paper is on systems for district heating for which there are five PhDstudents, three at universities and two at companies. The PhD students allstarted during the early part of 2014 and their initial work has concentratedon literature studies and on setting up models and data collection to be usedfor validation purposes. The PhD students will complete their studies in2017-18.

  • 12.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Parameter identification manual for TRNSYS models at SERC2001Report (Other academic)
  • 13.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    ”Röriga” förluster i solvärmesystem2011In: Energimagasinet, ISSN 0348-9493, Vol. 2011, no 1, 42-43 p.Article in journal (Other academic)
    Abstract [sv]

    Villaägare med solvärme i kombination med annan värmekälla är nöjda med sina installationer. Solvärmekretsarna är väl installerade men ägarna och installatörerna är ovetandes om att det finns stora förluster i andra delar av systemen.

  • 14.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Slutrapport för EU-projekt Combisol P30784-12011Report (Other academic)
  • 15.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Slutrapport för EU-projekt SolNET P22416-12010Report (Other academic)
    Abstract [sv]

    SolNET var den första europeiska forskarskolan för termisk solvenergi med 10 doktorander, där sju gemensamma doktorandkurser utvecklades och genomfördes under projektets gång. Projektet stöddes av EU-programmet Marie-Curie från juni 2006 till maj 2010. Centrum för solenergiforskning SERC vid Högskolan Dalarna deltog med en doktorand, Janne Paavilainen. SERC genomförde den första av doktorandkurserna, om dynamisk systemsimulering. 30 studenter deltog från 16 länder varav 22 var doktorander och tre var från industri. Under 2007 genomförde Paavilainen en teknoekonomisk utvärdering av mellanstora pellet- och solvärmesystem för närvärme som presenterades vid konferensen Eurosun 2008. Resultaten visar under vilka förutsättningar som solvärme kan vara ekonomisk lönsamt i närvärmesystem i Sverige och Finland. Paavilainen har varit medförfattare till en tidsskriftsartikel om SERCs simuleringsmodell för pelletspannor och –kaminer samt varit medförfattare till två tidsskriftsartiklar tillsammans med SPF (Schweiz) och TU Graz (Österrike) om en ny pannmodell för gas, olja och pellets. Dessa två validerade modeller i programmet TRNSYS används nu rutinmässigt i Sverige av SP och SERC och i Europa av ett flertal forskargrupper. Den nya pannmodellen som utvecklades med SPF och TU Graz har också införlivats i programmet Polysun som används av flera hundra användare runt hela världen, inkl. SERCs magisterstudenter.

  • 16.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Suggested Contents for Training on Solar Combisystems for Installers2011Report (Other academic)
  • 17.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Viktigt med helhetstänk i solvärmesystem2011In: VVS-Forum, ISSN 0346-4644, Vol. 3, 107-109 p.Article in journal (Other academic)
    Abstract [sv]

    Nöjda ägare och väl installerade solvärmekretsar – slutsatser från ett EU-projekt där en mängd solvärmesystem undersökts genom långtidsmätningar. Undersökningen visar också att den lilla spillvärme man ofta vill ha i källaren ger större värmeförluster än man tror.

  • 18.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Ayadi, Osama
    Modelling of a Commercial Absorption Heat Pump with Integral Storage2009In: Effstock 2009 - The 11th International Conference on Energy Storage, Stockholm, 2009Conference paper (Refereed)
  • 19.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Battikh, Michel
    Nielsen, Jan Erik
    Comparison of Simple EPBD Calculation Tool for Solar Combisystems with TRNSYS2010In: Eurosun 2010, Graz, Austria, 2010Conference paper (Other academic)
    Abstract [en]

    An excel based calculation tool has been developed within the EU project Combisol. It implements the standard calculation method EN 15316-4-3 for solar combisystems, as defined for the Energy Performance of Buildings Directive (EPBD). A base case system and building were defined and a number of parametric studies were performed with this EPBD tool as well as TRNSYS for the same systems and boundary conditions. For all the simulations in this study, the EPBD tool predicted a greater solar contribution than detailed TRNSYS simulations predicted. The difference was greater for Stockholm (high latitude) and Madrid (high solar fraction). Other studies showed that the EPBD predicted changes in solar contribution due to changes in system size, orientation and azimuth as well as store size in the same way that TRNSYS does.

  • 20.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Gantenbein, Paul
    Hauer, Andreas
    Henning, Hans-Martin
    Jaenig, Dagmar
    Kerskes, Henner
    Nuñez, Thomas
    Visscher, Klaas
    Thermal Properties of Materials for Thermo-chemical Storage of Solar Heat: Report B2 of Subtask B2005Report (Other academic)
  • 21.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Gantenbein, Paul
    Jaehnig, Dagmar
    Kerskes, Henner
    van Essen, Martijn
    Weber, Robert
    Zondag, Herbert
    Chemical and Sorption Storage – Results from IEA-SHC Task 322008In: Eurosun 2008, Lisbon, 2008Conference paper (Other academic)
    Abstract [en]

    Six main groups have studied chemical and sorption storage within IEA-SHC Task 32 “advanced storage concepts for solar and low energy buildings”. Closed and open adsorption systems, two and three phase absorption as well as chemical storage have been studied. The main results of the work are: identification of potentially suitable materials for long term storage of solar heat and publication of material properties; development of new concepts of short and long term storage of solar heat to prototype stage with lab and field tests; development of models for simulation of chemical and sorption storage; simulation of three systems with long term chemical or sorption storage with the Task 32 boundary conditions; and support in the commercialisation of a chemical heat pump with short term thermal storage for solar heating and cooling applications. The main conclusion from the work is that there are a number of promising technologies and materials for seasonal storage of solar heat for single families but that a lot of research is required before it can be become practical and economical.

  • 22.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Gantenbein, Paul
    Jaenig, Dagmar
    Kerskes, Henner
    Summer, Karola
    van Essen, Martijn
    Weber, Robert
    Laboratory Tests of Chemical Reactions and Prototype Sorption Storage Units: Report B4 of Subtask B2008Report (Other academic)
    Abstract [en]

    Five laboratory prototypes of thermochemical and sorption storage are described in this report as well as the material characterisation of a promising thermochemical reaction with MgSO4.7H2O. Measured results and projected heat storage densities for units of 70 and 1000 kWh storage for single family houses are reported. Four of the five prototypes are closed sorption units and act as thermally driven heat pumps. Two work with absorption: three phase absorption process, Thermo Chemical Accumulator (TCA) with Lithium Cloride/water, and two phase absorption with Sodium Hydroxide/water. Two work with adsorption, one with zeolite and the other with silica gel. The fifth prototype that is reported, Monosorp, uses an open adsorption process integrated into a standard ventilation system with heat recovery. The different technologies are at very different stages of development. The TCA technology is in the process of commercialisation by the Swedish company ClimateWell AB, and over 35 storage systems have been delivered, mostly in Spain. The other technologies are in the prototype stage with no companies intending to develop and market them. The Modestore store (silica gel /water) was developed in a European project, and the main company within the project (Sortech) is commercialising the technology as a heat pump with essentially no heat storage. The storage density for cold (based on total system volume), when compared to water, is more favourable than for heat. For the ClimateWell 10 commercial heat pump/store, the storage density for cold is 4.7 that of water whereas for heat it is only 1.2 times greater. This is due to the fact that the temperature range available for water storage for cold is much smaller (~10°C) than for heat (~60°C). For short term heat storage, none of the technologies have a significant advantage compared to water in terms of storage density. The energy density can only be slightly greater than that for water, mainly due to the space required for heat exchangers and other components. The best technology in this aspect is Monosorp, which has a density twice that of water. In addition all of the storage systems have irreversibilities in the processes themselves during charge and discharge. Most of this is due to the different temperature levels of charge/discharge and the related sensible energy between these. For longer term storage (1000 kWh) the energy density for the TCA technology and NaOH storage systems is nearly three times that of water, for Monosorp twice and for MgSO4.7H2O nearly. In addition, once the sensible heat from the solution has been lost (or at best recovered), the energy can be stored indefinitely, a significant advantage compared to water. In terms of material cost, all materials are expensive compared to water. However, NaOH, zeolite 4A and MgSO4.7H2O are significantly less expensive than the other materials reported, LiCl, silica gel and zeolite 13X. The cost for the whole storage system has not been estimated here. For the ClimateWell 10, the projected cost is ~8000€ for a heat pump system consisting of two units in parallel, with a total heat storage capacity of 70 kWh.

  • 23.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Gantenbein, Paul
    Jaenig, Dagmar
    Kerskes, Henner
    van Essen, Martijn
    Weber, Robert
    Zondag, Herbert
    Final Report of Subtask B “Chemical and Sorption Storage”: Report B7 of Subtask B2008Report (Other academic)
    Abstract [en]

    This report is the final report of a Subtask of the Task 32 “Advanced Storage Concepts for solar and low energy buildings” of the Solar Heating and Cooling Programme of the International Energy Agency. As a final report of a Subtask it has two aims: 1. it summarizes all the works conducted in the Subtask during the period of the Task (June 2003 – December 2007) highlighting some important results that the participants in the Subtask reached and it refers to all the detailed documents that have been produced by the Subtask and Task 32, 2. it presents some hints on the management of an IEA Subtask in order to improve future collaborative works within this framework In Subtask B, major achievements have been: 1. Identification of potentially suitable materials for long term storage of solar heat and publication of material properties. 2. Documentation of State of the Art in chemical and sorption storage in Task 32 Handbook. 3. Development of new concepts of short and long term storage of solar heat to prototype stage with lab and field tests. 4. Development of models for simulation of chemical and sorption storage. 5. Simulation of three systems with long term chemical or sorption storage with the Task 32 boundary conditions (reports for only two of these were completed). 6. Support in the commercialisation of a chemical heat pump with short term thermal storage for solar heating and cooling applications. 7. Input for the storage part of the strategic research agenda of the European Solar Thermal Technology Platform, further refining the compact heat storage R&D questions that should be tackled on an international level. IEA SHC – Task 32 – Advanced storage concepts

  • 24.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Gantenbein, Paul
    Jaenig, Dagmar
    Kerskes, Henner
    Visscher, Klaas
    Chemical and Sorption Storage - Selection of Concepts: Report B1 of Subtask B2005Report (Other academic)
  • 25.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Jaenig, Dagmar
    Gantenbein, Paul
    Weber, Robert
    Laboratory Prototypes of Thermo-Chemical and Sorption Storage Units: Report B3 of Subtask B2007Report (Other academic)
    Abstract [en]

    Four laboratory prototypes are described in this report. Measured results and projected heat storage densities for units of 70 and 1000 kWh storage for single family houses are reported. All four prototypes are closed sorption units and act as thermally driven heat pumps. Two work with absorption: three phase absorption process (TCA) with LiCl-water, and two phase absorption with NaOH-water. Two work with adsorption, one with zeolite and the other with silica gel. The different technologies are at very different stages of development. The TCA technology is in the process of commercialisation by the Swedish company ClimateWell AB, and over 20 storage systems have been installed, mostly in Spain. A further 100-200 are planned for 2007. The other technologies are in the prototype stage with no companies intending to develop and market them. The Modestore store was developed in a European project, and the main company within the project (Sortech) is commercialising the technology as a heat pump with essentially no heat storage. The storage density for cold, when compared to water, is more favourable than for heat. For the ClimateWell 10 commercial prototype the storage density for cold is 4.7 that of water whereas for heat it is only 1.2 times greater. This is due to the fact that the temperature range available for water storage for cold is much smaller (~10°C) than for heat (~60°C). For short term heat storage, none of the technologies have a significant advantage compared to water in terms of storage density. The energy density can only be slightly greater than that for water, mainly due to the space required for heat exchangers and other components. In addition all of the storage systems lose heat during the charge and discharge process due to irreversibilities in the processes themselves. Most of this is due to the different temperature levels of charge/discharge and the related sensible energy between these. For longer term storage (1000 kWh) the energy density for the TCA technology and NaOH storage systems is nearly three times that of water. In addition, once the sensible heat from the solution has been lost, the energy can be stored indefinitely, a significant advantage compared to water. In terms of material cost, all materials are expensive compared to water, with NaOH being by far the least expensive. The cost for the whole storage system has not been estimated here. For the ClimateWell 10, the projected cost is ~8000€ for a heat pump system consisting of two units in parallel, with a total heat storage capacity of 70 kWh.

  • 26.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Jaenig, Dagmar
    Kerskes, Henner
    Zondag, Herbert
    Store Models for Chemical and Sorption Storage Units: Report B5 of Subtask B2008Report (Other academic)
    Abstract [en]

    Storage models have been developed for four of the storage concepts that have been studied within Subtask B of IEA-SHC Task 32. These are available from the authors. They are: 1. Thermo-chemical accumulator model for the commercial product ClimateWell 10; 2. detailed model for open adsorption in a zeolite honeycomb structure; 3. simple theoretical model for generic chemical reactions; and 4. closed adsorption store model. Two of the models have been developed in TRNSYS directly, whereas one has been developed in Matlab and the fourth as a PEDX routine. The latter two models can be linked to TRNSYS and can thus be used in system simulations with the Task 32 boundary conditions. The models vary significantly in detail and require varying degrees of measurements for identifying parameters. For each model, the basic function of the store is described in addition to the model itself. The main assumptions and limitations of each model are stated. Finally details are supplied about the validation of the model.

  • 27.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Martin, Andrew
    Udomsri, Seksan
    Slutrapport för EU-projekt Polysmart P22374-12010Report (Other academic)
    Abstract [sv]

    Följande sammanfattar erfarenheterna inom projektet: - Besparing av primärenergi är väldigt beroende av ett fåtal faktorer där primärenergi faktor för generering av el till nätet är avgörande. I projektet använde man termen ”non-renewable primary energy” där förnybara källor som bioenergi och även sopförbränning har väldigt låga värden. Om man använder den europeiska mixen för elproduktion ger enbart kraftvärme nästan alltid besparing av primär energi. Det samma gäller system där man använder förnybar energi eller sopförbränning. För system med trigenerering som använder fossila bränslen måste man ha både hög andel elproduktion från kraftvärmeaggregatet och relativt hög COP för den värmedrivna kylmaskinen om man ska få en besparing av primärenergi. - Systemen är komplexa och man har lärt sig mycket inom projektet. Dock har man inte kommit så långt som standard systempaket. - Elförbrukning är oftast högre än förväntat och i verklighet högre än specificerat. - Värmesänkan i systemet är en nyckelkomponent som är kritiskt för bra systemprestanda. Mer FoU krävs för att få fram komponenter som lämpar sig väl till sådana system (och som skulle också gynna andra system). - Mätning av systemet med tillhörande analys har behövts för att förbättra systemprestanda, vilket är kopplat till att system är komplexa och att det inte fanns en grundläggande kompetens i början av projektet hos alla partners. - Lovande nischmarknader har identifierats men de kräver förmodligen paketlösningar som inte finns på marknaden än. - Man ska enbart täcka baslasten med trigenereringssystem. - Koppling med fjärrvärme kan fungera bra men leverantören måste acceptera relativt höga returtemperaturer.

  • 28.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Nielsen, Christian
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Peréz de la Mora, Nicolás
    Sotnikov, Artem
    Louvet, Yoann
    Bava, Federico
    Shantia, Alireza
    Lennermo, Gunnar
    Seven Phd Studies on Solar District Heat2014In: EuroSun 2014 / ISES Conference Proceedings (2014), ISES , 2014Conference paper (Other academic)
    Abstract [en]

    The Solar Heat Integration NEtwork (SHINE) is a European research school in which 13 PhD students in solar thermal technologies are funded by the EU Marie-Curie program. It has five PhD course modules as well as workshops and seminars dedicated to PhD students both within the project as well as outside of it. The SHINE research activities focus on large solar heating systems and new applications: on district heating, industrial processes and new storage systems. The scope of this paper is on systems for district heating for which there are six PhD students, three at universities and two at companies. In addition there is a seventh PhD in a Swedish national research school focused on energy efficiency within district heating networks (Reesbe). The initial work has concentrated on literature studies and on setting up initial models and measurement setups to be used for validation purposes. Some results of these studies are presented in the paper. The PhD students will complete their studies in 2017-18.

  • 29.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Thür, A.
    Letz, T.
    Comparison of Expansion Vessel Calculation Tools for “Boil-Back” Stagnation Protection2011Report (Other academic)
  • 30.
    Baranger, Renaud
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Performance Analysis of a Grid-Connected PV System in Borlänge, Sweden2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    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.

  • 31.
    Bastholm, Caroline
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Using locally available components and local knowledge to build sustainable stand-alone power systems2013In: Symposium Small PV-Applications : rural electrification and commercial use ; Ulm, Germany, June 17th/18th, 2013, Regensburg: Ostbayerisches Technologie-Transfer-Institut eV (OTTI) , 2013Conference paper (Other academic)
    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.

  • 32.
    Bastholm, Caroline
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Henning, Annette
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    The use of three perspectives to make energy implementation studies more culturally informed2014In: Energy, Sustainability and Society, ISSN 2192-0567, Vol. 4, no 3Article in journal (Refereed)
    Abstract [en]

    In our research on the social and technical feasibility of a small-scale electrical power system in Tanzania, we have perceived a need for an alternative framework or method for social scientific studies of limited scope. The approach we suggest is also a response to the growing criticism of cultural ignorance with which many energy implementation projects are handled. Theories from Social Anthropology and Sociology form the core of the approach we present. In addition, concepts from Science and Technology studies are used, as well as lessons learned from History of Technology. We suggest that particular attention should be paid to three aspects: identification of social actors, perceptions of change, and long-term feasibility and sustainability. The approach has been developed and concretised through application in our research. To elucidate our suggested approach, we use examples and results from our ongoing research project, in which the 'Three-perspectives-approach' is currently applied. We have combined theories, approaches and knowledge from different disciplines in order to formulate a framework for studies of social aspects of energy projects that is structured, concise and comparable. The approach is developed to target multi-disciplinary researchers with limited training in social scientific research. It may also be used by project implementers, or as a way for social scientists to present their findings in a way that facilitates for non-social scientists to integrate them into practice. We suggest that the Three-perspectives-approach may be applied independently, os as a complement to other tools.  

  • 33.
    Bayer, Petra
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Nagy, Bálint
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Development of laboratory equipment on passive solar heating: Testing of PCM enhanced gypsum board2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Large thermal mass is an important physical property of a building. It plays significant role in decreasing the amplitude of internal air temperature swings caused by the weather circumstances. By this the energy consumptions of the buildings can be reduced both by decreasing heating and decreasing cooling demand. So it is easier to provide the human comfort with less usage of engineering equipment. Nowadays energy saving is relevant because of the energy price increasing due to resources of the fossil fuels are exhausting. The thermal mass depends on the specific heat and the density of the material. The phase change materials (PCMs) are a modern way to increase the thermal mass of the building since it uses the latent heat of the materials instead of the heavy mass. This technology is suitable for providing high thermal mass to building with light construction. The application of PCMs in building materials is in evolving phase. The results about these products are very promising. But the application in wide range of it requires more effort. This thesis is aimed at testing a prototype gypsum board with PCM encapsulation manufactured by BASF and a development of a new lab for further ESES student in SERC. The test was executed with two boxes, one built with this special gypsum board and one with conventional gypsum board. The test based on a theoretical part and a measurement part with the same environment; open air and laboratory location. The theoretical model well covers the measured result, showing that the special gypsum board has the expected effect on the air temperature.

  • 34.
    Beyanga, Philbert
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Small PV lamps for rural areas in Tanzania - a focus on female usage2008Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Most of the areas in Karagwe district are not connected to National grid electricity with the exception of two centres (Kayanga & Omurushaka) which were connected in 1994. So the rest of the population are living dark relying mostly on small kerosene lamps for lighting. In 1995 KARADEA Solar Training Facility (KSTF) decided among other activities to supply solar lanterns in Karagwe district. The lanterns operated without many complaints for the first six months. After that period most of the lamps failed to operate properly which forced KSTF to terminate the sale of those lamps. In 2002 KSTF provided three kinds of the lamps to Solar Energy Research Centre (SERC), Sweden representing the types of lamps used in Karagwe for technical investigation whose results proposed among other things, further investigation of the solar lanterns. The aim of this thesis is to look for the better solution for lighting problems in Karagwe district, Tanzania. Women are the major focus due to their nature of work, especially in the evenings whereby they stay at home more time as compared to men preparing food and taking care of the children. Different light sources are discussed the main focus being small solar photo voltaic known also as solar lanterns. Several types of solar lanterns are analysed in detail and finally it is proposed that the Solar 2000 lamps be used in Karagwe.

  • 35.
    Blackman, Corey
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology. Mälardalen University.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Hallström, Olof
    Mälardalen University.
    Demonstration of Solar Heating and Cooling System using Sorption Integrated Solar Thermal Collectors2014In: EuroSun 2014 / ISES Conference Proceedings (2014), ISES , 2014Conference paper (Refereed)
    Abstract [en]

    Producing cost-competitive small and medium-sized solar cooling systems is currently a significant challenge. Due to system complexity, extensive engineering, design and equipment costs; the installation costs of solar thermal cooling systems are prohibitively high. In efforts to overcome these limitations, a novel sorption heat pump module has been developed and directly integrated into a solar thermal collector. The module comprises a fully encapsulated sorption tube containing hygroscopic salt sorbent and water as a refrigerant, sealed under vacuum with no moving parts. A 5.6m2 aperture area outdoor laboratory-scale system of sorption module integrated solar collectors was installed in Stockholm, Sweden and evaluated under constant re-cooling and chilled fluid return temperatures in order to assess collector performance. Measured average solar cooling COP was 0.19 with average cooling powers between 120 and 200 Wm-2 collector aperture area. It was observed that average collector cooling power is constant at daily insolation levels above 3.6 kWhm-2 with the cooling energy produced being proportional to solar insolation. For full evaluation of an integrated sorption collector solar heating and cooling system, under the umbrella of a European Union project for technological innovation, a 180 m2 large-scale demonstration system has been installed in Karlstad, Sweden. Results from the installation commissioned in summer 2014 with non-optimised control strategies showed average electrical COP of 10.6 and average cooling powers between 140 and 250 Wm-2 collector aperture area. Optimisation of control strategies, heat transfer fluid flows through the collectors and electrical COP will be carried out in autumn 2014.

  • 36. Broman, Lars
    et al.
    Börjesson, Kent
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Nordlander, Svante
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Rapport från/report from ISES Solar World Congress Hamburg September 13-18 19871988Report (Other academic)
  • 37. Broman, Lars
    et al.
    Figueroa, Eduardo
    Isaksson, Per
    Nordlander, Svante
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Workshop on PRESIM - a graphical preprocessor for modular simulation programs e.g. TRNSYS1988Report (Other academic)
  • 38. Broman, Lars
    et al.
    Lindberg, Eva
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Reflection losses from cylindrical concave absorber glazings and PV module surfaces1989Report (Other academic)
  • 39. Broman, Lars
    et al.
    Nordlander, Svante
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Solar cornets for concentration of sunlight onto solar cells1987Report (Other academic)
  • 40.
    Börjesson, Kent
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Mikroelektrifiering i Gambia - Resebrättelse 14-29 november 19881989Report (Other academic)
  • 41. Cantos-Soto, María Elena
    et al.
    Fernández-García, Aránzazu
    Matteudi, Maud
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Martínez-Arcos, Lucía
    Solar Reflectors Degradation Caused by Simulated Solar Radiation2012In: Solar PACES 2012, 2012Conference paper (Other academic)
    Abstract [en]

    The feasibility of concentrating solar power (CSP) technologies strongly depends on the material used toachieve a suitable solar reflector. A very relevant issue nowadays is to find a cost-effective reflector materialwith appropriate optical properties, able to resist the environmental stress and, therefore, extending itslifetime. This research work is focused on evaluating the thick silvered-glass reflector’s degradation causedby solar radiation onto different solar reflector samples, exposed to both experimental settings, simulatedsunlight under accelerated conditions and solar radiation at real outdoor conditions. The experiments havebeen performed in the optical characterization and durability of solar reflectors laboratory at the PlataformaSolar de Almeria (PSA). Three different chambers were used to reproduce the entire or specifics ranges ofthe solar radiation spectrum. Samples from 6 different manufacturers were placed inside of every sunlightchamber during 2000 hours. The outdoor exposure in the PSA precincts lasted for 4000 hours.

  • 42.
    Chen, Jiangxue
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Design of a 2.2 kW Solar PV Roof in Spain2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Interest and invest in the development and dissemination of photovoltaic technologies and projects have increased considerably. The main area of interest today is grid connected PV systems, especially in the countries which have favorable policies and economic incentives for photovoltaic applications. The project of this thesis is designed to be located in city of Jerez De La Frontera, Spain with a nominal power of 2.2MW. It is a rooftop PV system at a commercial parking lot, connected to the utility grid. There are mainly two phases of the design of the PV project:The preliminary design and optimised. In these two phases, configuration and each component of the PV rooftop system was designed and considered. And because this system design is for a real project belonging to the Spanish company AMT-Solar, some software popular in Spain and on-site data were used also.

  • 43. Chèze, David
    et al.
    Papillon, Philippe
    Leconte, Antoine
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Haller, Michel Y.
    Haberl, Robert
    Towards an harmonized whole system test method for combined renewable heating systems for houses2014Conference paper (Other academic)
    Abstract [en]

    The objective of this work is the development of harmonized efficiency test methods for combined renewable heating systems for houses, using a hardware-in-the-loop approach. An overview of the principles of the existing whole system test methods used by 3 research institutes involved in the project (MacSheep 2012) is given. Main objectives are realistic dynamic test sequence elaboration for solar and heat pump systems and comparison of results from tests achieved in different institutes. In order to reach these objectives, the first phase of the work aimed to harmonize the boundary conditions that comprise both the physical boundaries of the tested system as well as the climate and heat load definition, and this is presented in the first part of the article. The second part presents two methodologies to elaborate 12-days and 6-days whole system test sequences, validation results for solar and air source heat pump systems (SHP) and a methodology for achieving equal amount of space heat supplied by the tested system while at the same time providing a realistic response of the heat distribution system.

  • 44.
    Córdoba Candela, Jose
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Prefeasibility Study of a Central Solar Heating Plant with Seasonal Storage in Astana2015Independent thesis Advanced level (degree of Master (Two Years)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The feasibility of a Central solar heating plant with seasonal storage (CSHPSS) in a new district in Astana was evaluated. A total usable footprint of 481271 m2 of low energy (passivhaus standards) multi storey apartment blocks and single family houses (15000 expected inhabitants) was studied.

    Astana is a very cold climate, with heating degree days (below 18 °C) of 5724 °C.day/year. However the solar radiation is higher than in northern Europe (where most CSHPSS are located). Space heating demand, using passivhaus standards, would be 7.2 GWh/y, DHW demand calculated was 11 GWh/y and transmission losses 2.41 GWh/y.

    Astana’s DH network was studied in order to analyze the integration of this solar thermal system within the city network. Nevertheless due to its typology (open system) and its temperature regime a newly built DH within the existing network is chosen, a secondary 60/30 °C network is considered to be appropriate. Previous plants and technologies used in central plants were reviewed in order to select the most appropriate ones.

    In the simulation, collector areas between 1.4 and 2.5 m2 per MWh heat demand and water storage volumes between 1.2 and 4.0 m3 per m2 collector area satisfy between 41 and 81 per cent of the total heat demand by solar thermal heat. Levelized cost of energy (LCOE) increases from 0.099 €/kWh to 0.107 €/KWh when increasing the solar fraction. Two systems were selected as optimum (from LCOE point of view) that gave solar fractions of at least 50 % and 80 %.

    In order to calculate feed-in tariff, Net Present Value (NPV) and Payback Time (PBT), local economic figures were chosen considering different financial considerations resulting in a discount rate of 12% and inflation of 7%. Since the heat tariff for solar thermal is not defined by law, this tariff was calculated for an expected internal rate of return of 28%. For SF=50% the investment would have a feed-in tariff of 0.184 €/kWh, a PBT=8.2 years and NPV=9.92 M€. For SF=80% the investment would have a feed-in tariff of 0.191 €/kWh, a PBT=7.75 years and NPV=16.7 M€.

  • 45. Dahlgren, Lars
    et al.
    Börjesson, Kent
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Broman, Lars
    Solar measurement station in Borlänge1989Report (Other academic)
  • 46.
    Dalenbäck, Jan-Olov
    et al.
    Svensk Solenergi.
    Ollas, Patrik
    SP Energiteknik.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Biobränsle och solvärme för 100% förnybar värmeförsörjning: Projekt nr 30688-2 - Biobränsle och solvärme2015Report (Other academic)
  • 47. Dalenbäck, Jan-Olov
    et al.
    Pettersson, Ulrik
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Wood pellet and solar heating system development in Sweden. Initial result from system bench-marking test developments2011In: ESTEC 2011 -5th European Solar Thermal Energy Conference, Marseille, France, 2011Conference paper (Other academic)
    Abstract [en]

    Svensk Solenergi (Solar Energy Ass. of Sweden) and PellSam (Swedish Pellet Equipment Manufacturers Ass.) have joined forces to develop combined wood pellet and solar heating systems for the Nordic conditions. The cooperation has three main elements. A co-ordinated development project related to systems for single family houses (with co-financing from the Swedish Energy Agency), a common marketing campaign called “100%” (renewable heat) and certification of installers. The paper will focus on the development project. The development project comprises the development of a system design handbook and a combined system bench-marking and test method development. The test method (based on the Combitest method), is called Direct Characterization (DC) and the result is supposed to describe the annual system performance. It comprises laboratory measurements during 6 days on a whole system including (real) pellet boiler (or furnace), storage tank, controls and (simulated) solar collectors and load (based on selected weather data). The present set-up is for a typical single family building with 13 MWh space heating and 3 MWh DHW load. The test development has comprised a test of a reference boiler and 6 sample systems. Although all tested systems required less pellets than the reference boiler for the given load, only a few of the system designs take all aspects given in the handbook into account. The performance of the different systems varied a lot, from low 19 to high 37% less pellets than the reference boiler. The system tests have been carried out in two laboratories and one system has been tested in both laboratories with a reasonable agreement regarding the main parameters. The overall conclusion is that the test method seems to be possible to develop into a useful bench-mark method and that there are large possibilities for basic system improvements. Most of the tested systems consist of standard components combined into a system with a common control. Major system improvements are thus related to smaller boilers (furnaces) matched with improved and better insulated storage tanks (allowing reduced collector area) and better system controls (e.g. allowing less start and stop of the boiler/furnace). It is thus the intention to carry out a second round of system tests to include improved systems.

  • 48.
    Daryabegi, Maryam
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    State of the art of evacuated tube collectors2009Independent thesis Advanced level (degree of Master (Two Years))Student thesis
  • 49.
    El Kontar, Nabil
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Optimization of Grid-Connection Capacity for Wind Power Plants by Adding Photovoltaic Power2014Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    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.

  • 50.
    Elizondo, Asier Insausti
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Morrás, Javier
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Gas filled solar flat plate collector2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    We basically made a study of two similar flat plate collectors, in which the main difference was the gas filling of their chambers. One of them was supposed to have lower heat losses and so a higher efficiency due to the heavy gas filling of the collector. For that purpose a complete solar system was built in SERC, in which both type of collectors where connected in series and a valve system was used to run the system in different senses. Firstly the main part of the thesis has consisted in building a complete real installation. Secondly we wanted to be able to make a trustworthy performance test that could give us feasible reference values of how each collector worked, how they gained energy and how they lost heat. And of course a performance test that could give as data to plot an efficiency diagram of each collector. The performance of the whole system has also been tested in both flow senses. And finally a third part has been included, in which, we tried to demonstrate how due to the sealing of the gas filled chamber, the pressure changes in the chamber affected in the movement and effort that the cover and absorber had to suffer. Distance measurements have been taken between the glass and the absorber at different temperatures. This report consists in a theoretical explanation of how the installation has to be built and how we have done it. A description of what are the theoretical requirements needed to do the performance test, which were the steps that had to be followed and how we did it. In the last part of the report results of the testing and the distance measurements are shown with their conclusions and discussions. Nevertheless our practical work has shown us that theory is often far from real life, and lower efficiency values than we expected have been seen during all our work. On the other hand, some interesting results have been obtained related to the distance measurements as they have clearly shown us how the absorber suffers while exposed to different conditions.

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