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  • 151.
    Krishnan, Prasanna
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Bevavior of silicon thin-film multi-bandgap solar cells under Dutch illumination conditions2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The aim of this research was to observe how operating temperature affected output, and how spectral variation affected current matching for unique triple cells produced at Utrecht University (UU). It was important to use data and boundary conditions that would simulate Dutch weather conditions. The effect of cell operating temperature was studied by warming up the cells in discrete steps over a range of temperatures and monitoring the trend in open circuit voltage and efficiency. The current matching of the three subcells was studied for two triple cells. One was well matched (currents were within 11% of each other) under standard test conditions (STC) while the other was poorly matched (currents varied by up to 45%) under STC. This was the baseline for comparison. Modelled spectral data based on measured irradiation data was available. Data for four days of the year – one clear and one cloudy day in June, and one clear and one cloudy day in December – was used for the research. Using the measured data and the spectral response of the cells, the current matching during each hour of daylight of each day was found. The temperature tests revealed that the triple cells had a temperature coefficient of efficiency of -0.27 %/ºC. While temperature performance of silicon triple cells is a relatively new area of study, these results did agree with established results for tandem cells using amorphous and microcrystalline layers. The spectral variation study showed that a slight change in the daily spectrum caused very dramatic changes in current matching. The best matching was on the clear June day, when the measured spectrum was close to the reference AM1.5 spectrum. The subcell currents in the well matched cell were within 14% of each other, while the poorly matched cell's currents were within 50% of each other. The worst matching was on the cloudy December day. The top cell had an output 38% higher than the current limiting cell in the well matched cell. In the poorly matched cell, its output was 75% higher than the current limiting middle cell. Overall, it was evident that deviations from the AM1.5 spectrum led to poorer current matching. This is a major issue that must be studied further in future cell designs.

  • 152.
    Kroner, Marie-Désirée
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Gaied, Noureddine
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Redesign and Testing on a PV-Wind Hybrid System2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The purpose of the thesis is to renew the PV-Wind hybrid system of Högskolan Dalarna. An analysis of the small scale wind turbine market is done to select a suitable wind turbine. The system is redesigned to unite as many of the old components as possible with the necessary new ones. The BWC XL.1-24 from Bergey Windpower is installed and the system is monitored. The function tests have shown that the system functions works.

  • 153.
    Küchler, Stefan
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Solar Energy assessment based on weather station data for direct site monitoring in Indonesia2013Independent thesis Advanced level (degree of Master (One Year)), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    This thesis evaluates different sites for a weather measurement system and a suitable PV- simulation for University of Surabaya (UBAYA) in Indonesia/Java. The weather station is able to monitor all common weather phenomena including solar insolation. It is planned to use the data for scientific and educational purposes in the renewable energy studies. During evaluation and installation it falls into place that official specifications from global meteorological organizations could not be meet for some sensors caused by the conditions of UBAYA campus. After arranging the hardware the weather at the site was monitored for period of time.

    A comparison with different official sources from ground based and satellite bases measurements showed differences in wind and solar radiation. In some cases the monthly average solar insolation was deviating 42 % for satellite-based measurements. For the ground based it was less than 10 %. The average wind speed has a difference of 33 % compared to a source, which evaluated the wind power in Surabaya. The wind direction shows instabilities towards east compared with data from local weather station at the airport.

    PSET has the chance to get some investments to investigate photovoltaic on there own roof. With several simulations a suitable roof direction and the yearly and monthly outputs are shown. With a 7.7 kWpeak PV installation with the latest crystalline technology on the market 8.82 MWh/year could be achieved with weather data from 2012. Thin film technology could increase the value up to 9.13 MWh/year. However, the roofs have enough area to install PV. Finally the low price of electricity in Indonesia makes it not worth to feed in the energy into the public grid.

  • 154. Larsson, Stefan
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Inomhusskidbacke i Lindvallen, Sälen2009Report (Other academic)
    Abstract [sv]

    Marknaden för inomhusskidbackar är tydligt under en kraftig expansion runt om i världen. Det finns ett 40-tal inomhusskidbackar i drift och ytterligare en rad projekt planeras. I Sverige finns hittills ingen inomhusskidbacke i drift. Det finns planer på ett mindre antal inomhusskidbackar ifrån Västernorrland och söderut. I dagsläget finns konkreta planer på större inomhusskidbackar i såväl Fränsta samt Isaberg med investeringar i storleksordningen 300 MSEK vardera, men ekonomin har gjort att byggstarten skjutits upp. Klimateffekten omnämns ofta som en drivkraft, dock kan det noteras att majoriteten av projekten innehåller mycket mer än inomhusskidbacken, i form av en rik flora av andra nöjes- och fritidsaktivteter. Beräkningar har gjorts på en 1000 m lång, 100 m bred och 250 m hög inomhusskidbacke vid Lindvallen, Sälen. Energiförbrukningen beräknas bli ca 16 kWh/m2 för kyla och uppvärmning för en backe med -3 graders lufttemperatur och året-runt-drift. Anläggningens totala energiförbrukning (inkl. snötillverkning, driftsel, skidlift mm) blir i storleksordningen 3-4 gånger större, och är bl a beroende på hur snön kommer att tillverkas och distribueras inom anläggningen. Erfarenheter verkar peka på att extern snötillverkning där den färdiga snön tillförs backen är att föredra samt att hög luftfuktighet reducerar mängden snö som måste tillföra.

  • 155. Lennermo, Gunnar
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Perers, Bengt
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Pettersson, Ulrik
    Johansson, Mathias
    Underlag för utökad besiktning av bio- och solvärmesystem: Formulär med analyshjälp2011Report (Other academic)
    Abstract [sv]

    Det är svårt att på ett genomarbetat sätt, kontrollera en solvärmeanläggning som är i drift och det blir svårare när solvärmesystemet skall samverka med en biobränsleanläggning, som har sina speciella egenheter. Det enklaste och, som det kan tyckas, bästa sättet att kontrollera om en solvärmeanläggning fungerar, är att beräkna utifrån en värmemängdsmätare, som förhoppningsvis finns i anläggningen, hur mycket energi per m2 aktiv area som solfångaren har producerat per år. Om produktionen ligger mellan 300 – 350 kWh/m2 så är det bra. Det är dock så att en solvärmeanläggning borde kunna producera betydligt mer värme om den bara ges lite bättre förutsättning eller att den faktiskt kan ge mindre, men ändå uppfylla de krav som ställdes. Det behöver inte nödvändigtvis vara antalet producerade solfångar-kWh värme som är högt utan det viktigaste kanske är att antalet inbesparade kWh biobränsle är många. För att kunna få ett grepp om hur en solvärmeanläggning fungerar i sitt sammanhang så bör det totala systemet redovisas framför allt med avseende på: -Värmedistributionssystemets uppbyggnad. Var och när finns kallt vatten som ska värmas samt hur mycket. -Energi- och effektnivåer för olika delar av systemet och fram för allt under sommaren -Vilka pannor och bränslen som används, framför allt med betoning på reglerbarhet Solvärmekretsen, som inte är speciellt annorlunda utformad än i andra lite större solvärmeanläggningar ges i den här rapporten relativt stort utrymme, eftersom den samlade kompetensen bland de som gör besiktningar och kontroller inte är så hög. De delar som berörs mest är: -Trycket i solvärmeanläggningen med avseende på expansionskärlets förtryck, systemets uppfyllnadstryck och driftsfunktioner -Flödet i anläggningen som inriktar sig på luftmedryckning, flödesfördelning och vanliga flödeshastigheter -Solfångarnas energi- och värmeeffektproduktion Huvuddelen av underlagsmaterialet bör ha samlats in före besöket, genom att försöka få tag på: -Förstudier för solvärme- och pannanläggning -Förfrågningsunderlag för i första hand solvärmeanläggningen -Driftstatistik -Data på hur det totala systemet ser ut. Dessa data bör bearbetas innan besöket på plats vilket skall inkludera en genomgång av driftsansvarig vilket kompletteras med en guidad tur genom anläggningen. Besöket bör också vara förberett hos driftsansvariga så att stegar för att komma åt solfångarna finns framtagna och de säkerhetsselar som skall finnas vid okulär inspektion finns tillgängliga. Efter avslutad på platsen kontroll ska en besiktningsrapport skrivas. Mycket underlagsberäkningar ska skickas med som bilaga samt en lista med punkter som syftar till att få en effektivare sol- och biobränsleanläggning.

  • 156. Lennermo, Gunnar
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Perers, Bengt
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Pettersson, Ulrik
    Johansson, Mathias
    Underlag för utökad besiktning av sol- och biovärmesystem2011Report (Other academic)
    Abstract [sv]

    Det är svårt att på ett genomarbetat sätt, kontrollera en solvärmeanläggning som är i drift och det blir svårare när solvärmesystemet ska samverka med en biobränsleanläggning, som har sina speciella egenheter. Det enklaste och, som det kan tyckas, bästa sättet att kontrollera om en solvärmeanläggning fungerar, är att beräkna utifrån en värmemängdsmätare, som förhoppningsvis finns i anläggningen, hur mycket energi per m2 aktiv area som solfångaren har producerat per år. Om produktionen ligger mellan 300 – 350 kWh/m2 är det bra. Det är dock så att en solvärmeanläggning borde kunna producera betydligt mer värme om den bara ges lite bättre förutsättning eller att den faktiskt kan ge mindre, men ändå uppfylla de krav som ställdes. Det behöver inte nödvändigtvis vara antalet producerade solfångarkWh värme som är högt utan det viktigaste kanske är att antalet inbesparade kWh biobränsle är många. För att kunna få ett grepp om hur en solvärmeanläggning fungerar i sitt sammanhang bör det totala systemet redovisas framför allt med avseende på: • Värmedistributionssystemets uppbyggnad. Var, när och hur mycket kallt vatten ska värmas? • Energi- och effektnivåer för olika delar av systemet, framför allt under sommaren? • Vilka pannor och bränslen används, framför allt med betoning på reglerbarhet? Solvärmekretsen, som inte är speciellt annorlunda utformad än i andra lite större solvärmeanläggningar, ges i den här rapporten relativt stort utrymme, eftersom den samlade kompetensen bland de som gör besiktningar och kontroller inte är så hög. Mest berörda delar är: • Trycket i solvärmeanläggningen med avseende på expansionskärlets förtryck, systemets uppfyllnadstryck och driftsfunktioner • Flödet i anläggningen som inriktar sig på luftmedryckning, flödesfördelning och vanliga flödeshastigheter • Solfångarnas energi- och värmeeffektproduktion Huvuddelen av underlagsmaterialet bör ha samlats in före besöket, genom att försöka få tag på: • Förstudier för solvärme- och pannanläggning • Förfrågningsunderlag för i första hand solvärmeanläggningen • Driftstatistik • Data på hur det totala systemet ser ut Dessa data bör bearbetas innan besöket på plats, vilket ska inkludera en genomgång av driftsansvarig kompletterat med en guidad tur genom anläggningen. Besöket bör också vara förberett hos driftsansvariga så att stegar för att komma åt solfångarna finns framtagna och de säkerhetsselar, som ska användas vid okulär inspektion, finns tillgängliga. Efter avslutad på-platsen-kontroll ska en besiktningsrapport skrivas. Mycket underlagsberäkningar ska skickas med som bilaga samt en lista med punkter som syftar till att få en effektivare sol- och biobränsleanläggning.

  • 157. Letz, T.
    et al.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Breidler, J.
    Mette, B.
    D4.1 : Specifications for the monitoring, collection and evaluation of results2009Report (Other academic)
  • 158. Letz, T.
    et al.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Heier, Johan
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Thür, A:
    Breidler, J.
    Mette, B.
    Ullman, J.
    Cholin, X.
    Pradier, G.
    D4.4 : Jämförelse av resultat från alla uppmätta anläggningar2010Report (Other academic)
  • 159. Letz, T,
    et al.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Mette, B.
    Breidler, J.
    D4.2 : Guidelines for calculation of savings indicators2009Report (Other academic)
  • 160. Letz, Thomas
    et al.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Perers, Bengt
    A new concept for combisystems characterization: the FSC method2009In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 83, no 9, p. 1540-1549Article in journal (Refereed)
    Abstract [en]

    Solar combisystems are relatively complex systems with many different components and operational parameters. Before the beginning of IEA-SHC Task 26 ("solar combisystems"), no method was available with which they could be compared. The well known "f-chart" method was introduced by Duffie and Beckman already in the seventies, but was only useful for dimensioning generic combisystems, with a defined hydraulic scheme. It didn't give a method to compare different designs. The objective of this work was to develop a simple tool for characterizing the performance of these systems. The method used was to analyse the comprehensive simulation results of Task 26 and to look for relationships between the key external factors of climate and load, and the system performance. The result is a new and simple methodology for characterization of solar combisystems, called the fractional solar consumption (FSC) method. FSC is a dimensionless quantity, which takes simultaneously into account the climate, the space heating and domestic hot water loads, the collector size, its orientation and tilt angle, but which does not depend on the studied system design. The study shows that fractional energy savings, with and without parasitic energy included, can be expressed as a quadratic function of FSC. The relationship was shown to be valid for a wide range of conditions, but to be limited for certain parameters such as collector orientation and hot water load. The method has been used to create a nomogram and the computer design tool CombiSun.

  • 161.
    Lindberg, Eva
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Fiedler, Frank
    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.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Review of an International Master Programme in Solar Energy Engineering2008In: Eurosun 2008, Lisbon, 2008Conference paper (Other academic)
    Abstract [en]

    The European Solar Engineering School ESES is a one-year master programme that started in 1999 at the Solar Energy Research Center, SERC, Dalarna University College. The programme, run in English, consists of courses which cover passive and active solar thermal, solar energy for tropical climates, PV and PV/Hybrid system design, and have sections on topics such as economy and social aspects as well as other renewable energy sources. ESES is then finished with a research project as thesis work. Over the years the contents have been evolved and improved, and new experimental work has been introduced. The programme has been growing in popularity over the years, with over 20 students each year. Approximately half of the students come from Europe, the rest coming from all over the globe. This paper describes the contents and experiences from eight years of running the programme. The majority of the students from ESES have found work in the solar industry, energy industry or taken up PhD positions. An alumni group has been started that actively gives support to past, present and potential future students.

  • 162.
    Lindström, Anders
    et al.
    Dalarna University, School of Technology and Business Studies, Forest and Wood Technology. School for Forest Management, Swedish University of Agricultural Sciences, Skinnskatteberg.
    Stattin, Eva
    Dalarna University, School of Technology and Business Studies, Forest and Wood Technology.
    Gräns, Daniel
    Dalarna University, School of Technology and Business Studies, Forest and Wood Technology. School for Forest Management, Swedish University of Agricultural Sciences, Skinnskatteberg.
    Wallin, Elisabeth
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology. School for Forest Management, Swedish University of Agricultural Sciences, Skinnskatteberg.
    Storability measures of Norway spruce and Scots pine seedlings and assessment of post storage vitality by measuring shoot electrolyte leakage2014In: Scandinavian Journal of Forest Research, ISSN 0282-7581, E-ISSN 1651-1891, Vol. 29, no 8, p. 717-724Article in journal (Refereed)
    Abstract [en]

    As indoor frozen storage is increasing in forest tree nurseries it is important to have accurate methods for assessing seedling storability in autumn and methods to determine post-storage vitality. Storability of spruce (Picea abies (L.) Karst.) and pine (Pinus sylvestris L.) seedlings can be based on determination of dry matter content (DMC) of seedling shoots or by freezing shoots at -25 degrees C and thereafter measure electrolyte leakage (SELdiff-25). To compare these two methods we stored 1-year-old spruce and pine seedlings at different occasions during the autumn. To test if leakage of electrolytes from shoots (SEL) could indicate deteriorated vitality, we measured SEL at the end of storage. After storage seedling viability was determined in a three-week growth test, measuring shoot and root growth capacity (RGC). Determination of freezing tolerance (SELdiff-25) before storage had a better ability to predict the outcome of storage compared to the DMC test. Measuring SEL at the end of the frozen storage period accurately indicated seedling vitality. Seedlings with SEL of 0-5% had a high survival rate whereas SEL over 10% indicated low survival and growth capacity after storage. The SEL method has a potential to become a screening test for identifying batches of seedlings that have been damaged during storage in the nursery.

  • 163.
    Liss, Jan-Erik
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Ackumulerande fällaggregat i gallringsbestånd2010Report (Other academic)
  • 164.
    Liss, Jan-Erik
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Undersökning av efterfrågan på grön GROT2010Report (Other academic)
  • 165.
    Liss, Jan-Erik
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Danielsson, Bengt-Olov
    Långa toppar2010Report (Other academic)
  • 166.
    Liss, Jan-Erik
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Mattsson, Jan Erik
    Knubbved istället för vanlig ved?: slutrapport från projekt Styckeved för småskalig eldning2010Report (Other academic)
    Abstract [sv]

    Chunkwood is a wood fuel with a fuel particle length between 50 and 150 mm, i.e. with a size between wood chips and conventional firewood. Chunkwood can be produced and handled as rational as wood chips and can dry during storage like conventional firewood. This is known since long. In project Smallwood for small scale heating we have investigated if chunkwood can be used in a small scale as a fuel for heating detached houses in conventional firewood boilers as well as automatically fed to a boiler in a similar way as wood chips. We have also compared complete systems for small scale production, distribution and heating with chunkwood, wood chips and conventional firewood. Storage of chunkwood produced for testing small scale boilers confirmed that chunkwood can dry during storage at least as good as conventional firewood. Tests in different boilers for detached homes showed that chunkwood can be used in conventional firewood boilers as well as in automatically fed wood chips boilers. Chunkwood can be delivered to the customer to the same or lower cost as wood chips and firewood, but need much less handling by the customer than conventional firewood. However, if chunkwood is used in a conventional firewood boiler, it needs some handling by shovel and wheelbarrow. Technical development of handling from the storage to the boiler is needed. In a somewhat larger scale, e.g. a boiler for apartment blocks or a small district heating system, chunkwood should be very interesting as a replacement of fuel pellets or fuel briquettes. It would be interesting with some projects, which in this scale demonstrates the whole system from the forest to heat.

  • 167.
    Liss, Jan-Erik
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Nordén, Berndt
    Studie av storbuntaren Rogbico2010Report (Other academic)
  • 168.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Möten med husföretag2010Report (Other academic)
  • 169.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Möten med husföretag2010In: Klimatsmart villavärme / [ed] Henning, Annette, Borlänge: Författarna och SERC , 2010, p. 27-44Chapter in book (Other academic)
  • 170.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Solvärme i nybyggda hus2010Report (Other academic)
  • 171.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Solvärme i nybyggda hus2010In: Klimatsmart villavärme / [ed] Henning, Annette, Borlänge: Författarna och SERC , 2010, p. 47-61Chapter in book (Other academic)
  • 172.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Teknik för småskalig elproduktion2012Report (Other academic)
  • 173.
    Lorenz, Klaus
    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.
    Installera värmesystem.: Faktablad för installatörer2006Report (Other academic)
  • 174. Lundh, Magdalena
    et al.
    Wäckelgård, Ewa
    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.
    Qualitative investigation of the development of combined solar and pellet heating systems in Sweden2008In: Eurosun 2008, Lissabon, Portugal, 2008Conference paper (Other academic)
  • 175.
    Ma, Jiya
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    A control program for a photovoltaic driven boat2008Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    This thesis is a part of the solar boat project which made a solar driven boat for participation in Frisian Solar Challenge 2008 in Holland. The boat is built with a Photovoltaic system with energy storage. The aim of this thesis is to optimize running speed for reaching the shortest time to the final. The method to implement the aim is to develop a control program which includes two step functions. One is a prediction function and the other is a real-time control function using genetic algorithm. To implement the program, a mathematic model has been built. Besides, the approaches to calculate the boundaries related to weather conditions have been explained.The control program has been simulated and tested. Both functions in the control program worked. The results proved that genetic algorithm has improved the results but it is not suitable in every situation.

  • 176.
    Malik, Waseem
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    PV in Buildings - Analysis, Design & Case Study2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    This theses report is about theoretical study of building integrated photovoltaics and to make BIPV integral part of the houses in 3 different climatic locations Manchester (UK), Dubai (UAE) and Lahore (Pakistan). It starts with BREDEM which is about domestic energy models which also describes Domestic energy requirement, procedures and consumption patterns in line with building energy codes and guidelines for low energy buildings in UK. It also includes methods to calculate energy consumption and decide which portion of energy consumption can be replaced by using BIPV.Planning to install BIPV and simulation with PV Syst. is described, analyzed and concluded. Further domestic energy consumption is explained by selecting a family house in Dubai In absence of building energy codes and weather data. BIPV is planned and simulated by using PV Syst. since weather data for Dubai was not available therefore it is simulated by using closest latitude Karachi (Pakistan) data. Lastly domestic energy consumption is explained by selecting a family house in Lahore (Pakistan).Domestic energy consumption is explained by using HVAC system sizing procedures and building energy codes of Pakistan. BIPV is planned and simulated by using PV Syst. The idea behind this study is to investigate about domestic energy models in different climates by selecting a standard family house (3 bed room).Study also includes the patterns of energy consumption in line with the building energy codes and regulations at three locations i.e. UK, Dubai and Pakistan. Procedures to make BIPV integral part of the building to achieve certain SF of the energy consumption and certain part of the energy requirement is to be replaced by using BIPV. Difference in BIPV designs with respect to various climates and the use different components as per climatic conditions.

  • 177.
    Marks, Jörgen
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Mattsson, Jan Erik
    Nordlander, Svante
    Malning av pellets och dosering av pellets till pelletsbrännare2000Report (Other academic)
  • 178.
    Marks, Jörgen
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Mattsson, Jan Erik
    Wallin, Fredrik
    Träpulver i Torsångs värmecentral: Slutrapport från STEM-projekt P11122-1 Konvertering av oljepannor mindre än 1 MW till eldning med träpulver2005Report (Other academic)
  • 179. Mattsson Petersen, Cecilia
    et al.
    Berg, Per E.O.
    Nordlander, Svante
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Kartläggning av organiskt avfall2004Report (Other academic)
  • 180.
    Melo, Manuel
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Economic Evaluation of a Solar Charged Thermal Energy Store for Space Heating2013Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A thermal energy store corrects the misalignment of heating demand in the winter relative to solar thermal energy gathered in the summer. This thesis reviews the viability of a solar charged hot water tank thermal energy store for a school at latitude 56.25N, longitude -120.85W

  • 181.
    Muthalagappan, Narayanan
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Correlation of PID with other Reliability Tests for CIGS Solar Cells2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    With solar photovoltaic plants getting larger and larger, the balance in the system is getting important. Balance of the system is necessary to get the maximum power from the system by arranging its components in an optimal way. With PV systems having high DC voltages of up to 600V in USA and 1000V in Europe, the high voltage stress induced in the system is a lot. One of the effects created due to an imbalance in the system is the Potential Induced Degradation. Previous researchers have found out that the Potential Induced Degradation (PID) is due to the voltage imbalance in the string (a schematic arrangement of solar modules in a system) which is influenced by the environmental factors. The objective of the project is to characterize the electrical properties of different available CIGS solar cell types and to correlate other reliabilty tests with PID test to find out if PID has any correlation with the other degradation mechanisms. Thus 8 samples were requested from two different manufacturers of different CIGS solar cells which were tested and results were compared and analysed. Therefore it was found out some compostional structure prove stable against the PID. But changing the combinaton of the compounds have a difference. Some relational pattern of degradation with the Stability test was evident. Few of the previous finding were again confirmed with a new path of approach for the further researches.

  • 182.
    Nielsen, Caroline
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Travel Report from the first field trip within the SIDA supported project "Mini-grids supplied by renewable energy - improving technical and social feasibility: Including visits to Ihushi Development Center, Tweyambe Secondary School and Mavuno Project in Tanzania. Conducted in April 20112011Report (Other academic)
    Abstract [en]

    This report describes the outcome of the first visit to Tanzania, within the project "Mini-grids supplied by renewable energy - improving technical and social feasibility". The trip included visits to three different organizations; Ihushi Development Center (IDC) near Mwanza, TIDESO near Bukoba, and Mavuno Project in Karagwe. At IDC, a brief evaluation of the current power system was done and measuring equipment for long term measurements were installed. At all three locations investigations regarding the current and future electricity demand were conducted and connections to people relevant to the study were established. The report is including as well some technical specifications as some observations regarding organization and management of the technical systems. The trip was including only short visits and therefore only brief introductions to the different organizations, based on observations done by the author. The report is hence describing the author’s understanding of the technical system and social structures after only short visits to each of the organizations, and may differ from observations done at another point in time, over a different time period, or by some other person.This report describes the outcome of the first visit to Tanzania, within the project "Mini-grids supplied by renewable energy - improving technical and social feasibility". The trip included visits to three different organizations; Ihushi Development Center (IDC) near Mwanza, TIDESO near Bukoba, and Mavuno Project in Karagwe. At IDC, a brief evaluation of the current power system was done and measuring equipment for long term measurements were installed. At all three locations investigations regarding the current and future electricity demand were conducted and connections to people relevant to the study were established. The report is including as well some technical specifications as some observations regarding organization and management of the technical systems. The trip was including only short visits and therefore only brief introductions to the different organizations, based on observations done by the author. The report is hence describing the author’s understanding of the technical system and social structures after only short visits to each of the organizations, and may differ from observations done at another point in time, over a different time period, or by some other person.

  • 183.
    Nielsen, Caroline
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Fiedler, Frank
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Evaluation of a Micro PV-Diesel Hybrid System in Tanzania2012Conference paper (Refereed)
    Abstract [en]

    In April 2011 a monitoring system was installed to enable studies of the performance and the usage of a micro PV-Diesel Hybrid system at the Ihushi Development Center (IDC) near Mwanza in Tanzania. Estimations of the load have been obtained by a survey of installed appliances and interviews with users of installed equipment. The load profile obtained by measurements has been analyzed and compared to estimations of the energy use. Further, the system size and performance were studied.

  • 184.
    Nielsen, Christian
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology. Chalmers University.
    Haegermark, Maria
    Dalenbäck, Jan-Olof
    Analysis of a Novel Solar District Heating System2014In: ISES Conference Proceedings EuroSun 2014, International Solar Energy Society (ISES) , 2014Conference paper (Other academic)
    Abstract [en]

    This paper describes a new residential building area with a solar assisted block heating plant. The building area currently comprises 26 single family buildings, four small multifamily buildings, 6 terrace houses and a nursing home for elderly people with 64 apartments. All buildings are designed for a low heat demand    (<45 kWh a-1 m-2) and the total heated floor area is 14 000 m2.  The block heating system comprises a central 250 kW wood pellet boiler, about 700 m2 of distributed roof-integrated solar collectors and a novel heat distribution system. An initial evaluation indicates that designed heat demands, as well as the overall system performance including expected solar contribution, is likely to be met.  Reported measurements include annual (April 2013 – March 2014) heat balances for two substations with single family buildings, yearly solar energy gains (August 2013 – July 2014), and a monthly (March 2014) heat balance for the whole system.

  • 185. Nielsen, J E
    et al.
    Thür, A.
    Breidler, J.
    Kuhness, G.
    Letz, T.
    Pradier, G.
    Cholin, X.
    Papillon, P.
    Albaric, M.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Mette, B.
    Ullman, J.
    D6.3 : Riktlinjer för tillverkare2011Report (Other academic)
  • 186.
    Olasz, Attila
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Evaluation of a PV/T concentrating collector2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The paper deals with the evaluation of an experimental PV, thermal combined (PV/T) concentrating collector. The concentrator is a parabolic mirror with a supposed 20x concentration ratio, and so able to produce high temperatures. The cells used are attached on an aluminum bar in which water circulates and so cools the cells. This is necessary because of the cells’ temperature dependent working characteristic. In case of ideal operation both the electric and heat energy can be used. The present document tries to give a summary about the existing PV/T products and tries to evaluate a prototype. The evaluation contains the cells characterisation, optical and thermal analysis of the prototype collector.

  • 187.
    Ollas, Patrik
    et al.
    SP Technical Research Institute of Sweden.
    Kovacs, Peter
    SP Technical Research Institute of Sweden.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Testing and evaluation of heat storage tanks according to Eco Design and transitional methods2014Conference paper (Other academic)
    Abstract [en]

    In 2013 the Eco Design and Energy Labelling directives for water heaters and for space- and combination heaters came into force as regulations. Additionally, there is the option for “package labels” allowing for various combinations of e.g. solar collectors, boilers and storage tanks to be labelled by the supplier or the dealer. The package is then rated by means of energy calculations based on component data. In late 2013 SP Technical Research Institute of Sweden on behalf of the Swedish Energy Agency conducted a series of tests on five different hot water storage tanks available on the Swedish market for single-family houses. The objectives were to assess the feasibility of the transitional methods for storage testing and to provide an overview of the compliance of storage tanks on the Swedish market compared to the upcoming regulations. The tests were performed according to requirements for hot water stores as well as according to those for water heaters. Results point out some problems with the current methodology and show a need for improvement of tank performance for the tested models as only one out of five tanks got a rating C or better thus complying with the minimum requirements set by the regulation.

  • 188.
    Paavilainen, Janne
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Characterization of residential chimney conditions for flue gas flow measurements2012Report (Other academic)
    Abstract [en]

    A literature survey and a theoretical study were performed to characterize residential chimney conditions for flue gas flow measurements. The focus is on Pitot-static probes to give sufficient basis for the development and calibration of a velocity pressure averaging probe suitable for the continuous dynamic (i.e. non steady state) measurement of the low flow velocities present in residential chimneys. The flow conditions do not meet the requirements set in ISO 10780 and ISO 3966 for Pitot-static probe measurements, and the methods and their uncertainties are not valid. The flow velocities in residential chimneys from a heating boiler under normal operating condi-tions are shown to be so low that they in some conditions result in voiding the assumptions of non-viscous fluid justifying the use of the quadratic Bernoulli equation. A non-linear Reynolds number dependent calibration coefficient that is correcting for the viscous effects is needed to avoid significant measurement errors. The wide range of flow velocity during normal boiler operation also results in the flow type changing from laminar, across the laminar to turbulent transition region, to fully turbulent flow, resulting in significant changes of the velocity profile during dynamic measurements. In addition, the short duct lengths (and changes of flow direction and duct shape) used in practice are shown to result in that the measurements are done in the hydrodynamic entrance region where the flow velocity profiles most likely are neither symmetrical nor fully developed. A measurement method insensitive to velocity profile changes is thus needed, if the flow velocity profile cannot otherwise be determined or predicted with reasonable accuracy for the whole measurement range. Because of particulate matter and condensing fluids in the flue gas it is beneficial if the probe can be constructed so that it can easily be taken out for cleaning, and equipped with a locking mechanism to always ensure the same alignment in the duct without affecting the calibration. The literature implies that there may be a significant time lag in the measurements of low flow rates due to viscous effects in the internal impact pressure passages of Pitot probes, and the significance in the discussed application should be studied experimentally. The measured differential pressures from Pitot-static probes in residential chimney flows are so low that the calibration and given uncertainties of commercially available pressure transducers are not adequate. The pressure transducers should be calibrated specifically for the application, preferably in combination with the probe, and the significance of all different error sources should be investigated carefully. Care should be taken also with the temperature measurement, e.g. with averaging of several sensors, as significant temperature gradients may be present in flue gas ducts.

  • 189.
    Paavilainen, Janne
    et al.
    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.
    Feasibility of Solar Thermal Assisted Small Scale District Heating in Nordic Countries2008In: Eurosun 2008, Lisbon, 2008Conference paper (Other academic)
    Abstract [en]

    A feasibility study for combining solar thermal plants with small scale 0.5-2 MWth mobile district heating plants under north European conditions was done. The study was done from a heat service company point of view, trying to come up with generally applicable scenarios rather than case studies. It was found that if the saved fuel is mainly pellets, without subsidies it is difficult to find economically feasible payback periods within the plants estimated lifetime, even with moderate pellet price increases. With oil as saved fuel the feasible payback periods range between 10-20 years with an estimated 5% annual oil price increase. The costs of moving the solar plant to another locations were also considered. A rough estimation of these costs resulted in a prolonged payback period of 3-6 years, which is considered too long regarding the general plant payback periods.

  • 190. Papillon, Philippe
    et al.
    Albaric, Mickael
    Haller, Michel
    Haber, Robert
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Pettersson, Ulrik
    Frank, Elimar
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Whole system testing: the efficient way to test and improve solar combisystems performance and quality2011In: ESTEC 2011 Conference Proceedings, Marseille, France, 2011Conference paper (Other academic)
    Abstract [en]

    The market for small solar combisystems has so far stayed way behind its huge potential. One of the reason may be that the quality and the thermal efficiency of the systems installed in the field is often lower than expected. Compact prefabricated systems have the potential to substantially reduce the effort and cost for their installation. Nevertheless, thermal efficiency should be clearly evaluated by lab testing. Until now it has been difficult to determine an accurate performance rating for those systems, and even more difficult to compare them, because there were no common definitions of terms for that type of system. For the development of the market of compact pre-fabricated solar combisystems, the existence of uniform test methods, recognized by the whole solar industry, is important. As a first step towards this goal, this paper give an overview of the information given to the manufacturer by these methods in term of thermal efficiency and knowledge of their product. The objective of the complete system test is to evaluate the thermal efficiency of complete systems including storage, controller, auxiliary boiler, pumps, valves, etc., in the laboratory thanks to a semi-virtual approach where climate, collector field, building and domestic hot water draw off are emulated. Based on this, three different test methods lasting 6 to 12 days have been developed and successfully applied to a number of small compact solar combisystems. Unlike field tests that need much more time to show the behaviour and performance of a system for a whole year, this kind of test method produces comparable results within a few weeks. The whole system test reveals unexpected behaviour of the systems in most cases and in some cases this behaviour was also detrimental to the system performance. The manufacturers like this kind of test method not only for getting independent test results that show the potential of their system, but also for testing prototypes prior to market introduction. This can be explained by the fact that this kind of test gives reliable function control and performance data within a few weeks. This data is more detailed and has a higher accuracy than what the manufacturer can expect from a whole year of field test monitoring. The test methods are suited for the determination of the annual performance of solar combisystems, including also a full evaluation of their functions and interactions.

  • 191.
    Pazmino, Victor
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    PV-Wind Energy Hybrid Systems Techno-Economic Feasibility Analysis for Different Swedish Locations2007Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    The purpose of this thesis is to determine the feasibility of a standalone PV-Wind hybrid system on different Swedish locations for single family houses. PV-Wind hybrid systems have the potential to be more cost effective by compensating each other’s shortcomings. Techno-economic analyses have been done to show how the different locations in Sweden and types of load influence the sizing and system costs. Combined with hourly meteorological and load data, the performance of a PV-Wind hybrid system is determined on an hourly basis. The effect of the time step of the wind speed data on a wind energy system has also been investigated. The main simulation tool to be used in this thesis is HOMER (Hybrid Optimization Modeling Electric Renewables) developed by the National Renewable Energy Laboratory (NREL) in the United States of America. HOMER is a simulation tool designed to optimize the size of energy systems for defined boundary conditions. The optimization is based on economic figures such as the Net Present Cost (NPC). Another simulation tool, Windographer, developed by the same organization, is used to analyze data with time-step lower than an hour. Finally, TRNSYS is used to compare the energy output of a wind turbine for wind speed data with different average time steps. It has been shown on a previous study that because of the low winds in the region of Borlänge only low electricity consumption is economically feasible and be able to cover at least 90% of the total energy demand and keep a minimum comfort at the house. A new simulation for Borlänge has been performed and it showed a pure PV system is the economic solution if the capacity shortage allowance falls below 30%. This is not a problem because the minimum set of comfort level has been assumed to be 10%. On windy places like Lund it shows that a PV-Wind hybrid system is much more convenient in terms of system production and cost of energy compared to pure PV stand-alone system.

  • 192.
    Perers, Bengt
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    An improved dynamic solar collector model including condensation and asymmetric incidence angle modifiers2010Conference paper (Refereed)
  • 193.
    Perez de la Mora, Nicolas
    Dalarna University, School of Technology and Business Studies, Mechanical Engineering. Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Energy Storage for a Grid-Connected PV-System: A Feasibility Study2013Independent thesis Advanced level (degree of Master (One Year)), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    The work presented in this thesis concerns the dimensioning of an Energy Storage System (ESS) which will be used as an energy buffer for a grid-connected PV plant. This ESS should help managing the PV plant to inject electricity into the grid according to the requirements of the grid System Operator. It is desired to obtain a final production not below 1300kWh/kWp with a maximum ESS budget of 0.9€/Wp. The PV plant will be sited in Martinique Island and connected to the main grid. This grid is a small one where the perturbations due clouds in the PV generation are not negligible anymore.

    A software simulation tool, incorporating a model for the PV-plant production, the ESS and the required injection pattern of electricity into the grid has been developed in MS Excel. This tool has been used to optimize the relevant parameters defining the ESS so that the feed-in of electricity into the grid can be controlled to fulfill the conditions given by the System Operator. The inputs used for this simulation tool are, besides the conditions given by the System Operator on the allowed injection pattern, the production data from a similar PV-plant in a close-by location, and variables for defining the ESS. The PV production data used is from a site with similar climate and weather conditions as for the site on the Martinique Island and hence gives information on the short term insolation variations as well as expected annual electricity production. The ESS capacity and the injected electric energy will be the main figures to compare while doing an economic study of the whole plant. Hence, the Net Present Value, Benefit to Cost method and Pay-back period studies are carried on as dependent of the ESS capacity.

    The conclusion of this work is that it is possible to obtain the requested injection pattern by using an ESS. The design of the ESS can be made within an acceptable budget. The capacity of ESS to link with the PV system depends on the priorities of the final output characteristics, and it also depends on which economic parameter that is chosen as a priority.

  • 194.
    Perman, Karin
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Byggregler och småhustillverkare: Husens framtida utformning2010Report (Other academic)
  • 195.
    Perman, Karin
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Byggregler och småhustillverkare i Dalarna2010In: Klimatsmart villavärme? / [ed] Henning, Annette, Falun: Författarna och SERC , 2010, p. 63-72Chapter in book (Other academic)
  • 196.
    Perman, Karin
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Energy use as a political problem2011Conference paper (Other academic)
  • 197.
    Perman, Karin
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Från el till värme.: En diskursanalytisk policystudie av energiomställning på statlig, kommunal och hushållsnivå2008Doctoral thesis, monograph (Other academic)
    Abstract [sv]

    The aim of this thesis is to analyse how space heating for single-family houses, and en-ergy system conversion has been constructed and discussed at national, municipal and household levels. Political documents have been studied, and interviews have been car-ried out with politicians, civil servants and householders in the municipality of Falun. In order to study and analyse similarities and differences between these three political levels, the following main questions were asked: In which sense is the use of electrical heating formulated as problematic? How are the causes of these problems presented, and which solutions are suggested? What are the effects of how problems, causes and solutions are constructed? At the national level, the use of electricity produced by nuclear power was considered a problem. Initially the municipality’s policy documents present the same problem, but there is a change of focus to the problem of imported electricity produced by fossil fuel, and the resulting emissions. At household level, the problem was often an old and badly functioning space-heating system. But some households did not formulate a problem be-fore they converted. Instead they were influenced by their neighbours and thereby con-vinced. At all three political levels, there is consensus on the households’ responsibility con-cerning energy transition. While industry tends to be considered incapable of cutting down its energy consumption, households are expected to take the responsibility seri-ously. Furthermore, within the household, the heating system tends to be constructed as a predominantly male concern. At all three levels, households are perceived as dependant on economical subsidies when taking the decision to convert from electrical heating. Although it is interesting that the interviewed householders only apply this view to others than themselves. They are convinced that other households need subsidies to act in an environmentally correct way. The discourse concerning the Swedish energy transition illustrates a shift away from a definition of ecological modernisation where environmental considerations influence economic development. The thesis clearly shows how economic arguments repeatedly influence environmental concerns. However, the tension between the two is played down and concealed through the lack of problematisation of the responsibility of industry, and through the focus on the need for education and future opportunities. Political dialogues concerning the use of electrical heating and the conversion of energy systems towards more renewable energies are dominated by economic arguments at the three levels. One effect of this is an assumption that energy policy instruments such as information and economic subsidies are essential for the energy transition. However, if householders rather are influenced by their neighbours should the government use economic subsidy as the main energy policy instrument?

  • 198.
    Perman, Karin
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    af Klintberg, Tord
    Avdelningen för byggnadsteknik, KTH.
    Energieffektivisering av allmännyttan Jakobsgårdarna: Sociala, politiska, tekniska möjligheter och problem2013Report (Other academic)
    Abstract [sv]

    Denna rapport Energieffektivisering av allmännyttan Jakobsgårdarna behandlar bostadsbolaget Tunabyggens (Borlänge kommun) projekt Jakobsgårdarna, under perioden 2009 till och med juni 2012. Det finns skillnader i tekniskt-ekonomiskt möjliga energieffektiviseringsåtgärder och vad som faktiskt åtgärdas. Denna skillnad har benämnts "energieffektiviseringsgapet". I denna rapport beskrivs och studeras vilka sociala, kulturella, politiska och tekniska faktorer som har en tendens att vidga, respektive reducera, "energieffektiviseringsgapet". Det är en implementeringsstudie, där utgångspunkten är en interaktion mellan fastställande av mål och åtgärder för att uppnå dem.

    Studien lyfter upp två fokusområden. Fokusområdet styrmedel koncentreras till studier av hur de energipolitiska mål som formulerats nationellt och lokalt kan kopplas till projektet Jakobsgårdarna samt val av specifika styrmedel. Fokusområdet kommunikation inkluderar studier av hur förändringsplanerna formuleras och kommuniceras till boendegrupperingar och intresseorganisationer.

    Valda metoder är intervjuer, observationer av projektmöten, studier av offentliga handlingar, hemsidor och dokument från EU, regering, riksdag, och Borlänge kommun. En sonderande teknisk pilotinventering av Jakobsgårdarna har utförts, liksom en bearbetning och analys av energistatistik.

    Det som är viktigt för projektet fortskridande och därmed uppnå formulerade energieffektiviseringsmål är ekonomiska resurser för kostsamma renoveringar, kunskap om befintligt energisystem och möjliga energieffektiviseringsåtgärder, samt möjlighet att implementera ny energieffektiv teknik. Studien visar även att energieffektiviseringsarbetet är mer beroende av governancestyrning (ex SABO-initiativet) än hierarkisk styrning (ex energi- och klimatstrategin).

    Bostadsbolaget har ett ansvar att ombesörja bostäder för välbeställda liksom mindre välbeställda kommuninvånare. Man kan här ana en konflikt mellan energieffektiviseringsmålen, och kommunens aktuella bostadsbrist liksom lagen om kommunernas bostadsförsörjningsansvar.

    Ambitionen att involvera de boende i energieffektiviseringsarbetet förväntas leda till att de boende blir medveten om sin energianvändning, och att det i sin tur leder till minskad energianvändning. De projektansvariga förstår att de måste kommunicera olika frågor med de boende, men de boende är måttligt intresserade av energifrågor som tenderar att bli av väldigt teknisk karaktär.

     

     

     

     

     

  • 199.
    Perman, Karin
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Hedlund, Gun
    Örebro universitet.
    Politik, expertis och boende: Energieffektivisering i fallet jakobsgårdarna, Borlänge kommun2013Report (Other academic)
    Abstract [sv]

    Ett övergripande politiskt problem, från EU till Borlänge kommun, är den höga energiförbrukningen inom fastighets- och bostadssektorn, och precis som i många andra stadsdelsutvecklingsprojekt är tanken att via en fysisk förändring av området Jakobsgårdarna kan bostadsbolaget Tunabyggen även bidra till en social utveckling. Syftet med denna fallstudie är att undersöka hinder och möjligheter som kan uppstå i ett lokalt stadsutvecklingsprojekt med en ambition att energieffektivisera, med fokus på en minskad energianvändning vid uppvärmning av flerfamiljhus. Valda metoder är intervjuer, observationer av projektmöten, studier av offentliga handlingar, hemsidor och dokument från EU, regering, riksdag, och Borlänge kommun, under perioden januari 2009- juni 2012.

    För Tunabyggen har främjande faktorer i ett energieffektiviseringsarbete varit att delta i och själv skapa stödjande lokala nätverk. Den vaga formella politiska styrningen via ägardirektiv och politiker i bolagens styrelser ger ett stort handlingsutrymme för tjänstemännen i bolagen och förvaltningen och samverkansidealets beroende av god personkemi och varaktiga relationer skapar en sårbarhet.  Ytterligare en hindrande faktor i energieffektiviseringsarbetet är ett avbrott i kontinuiteten av både projektets och bolagets ledning, vilket delvis kan vara en effekt av att arbeta i projektform och en stor tilltro till externa experter. Ett annat dilemma är hur man lyckas säkerställa generationsväxling och kunskapsöverföring när det gäller drift och byggnation av ett bostadsområde.

    För att hantera energieffektiviseringsmålen och en begränsad budget diskuteras rivning av fastigheter, men bland annat kommunens aktuella bostadsbrist talar mot det. Denna målkonflikt leder i sin tur till att fokus riktas mot lagen om allmännyttiga kommunala bostadsaktiebolag  och revideringen från 1 januari 2011. Kommunernas handlingsutrymme att delfinansiera bolagens verksamhet omöjliggörs och försvårar en lokalt aktiv bostadspolitik.  Som en effekt framstår den nationella policyn om det offentligas ansvar att leda utvecklingen som svårlöst när det gäller energieffektivisering av de kommunala bolagens flerfamiljshus.

  • 200.
    Persson, Jon
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Övervakning och pulsad laddning av bly-syra batterier2012Report (Other academic)
    Abstract [sv]

    Arvika som en följd av samtal kring möjligheten att anpassa deras strömpulsbaserade rekonditioneringssystem, utvecklat för större truckbatterier, till att kunna återvinna förlorad kapacitet även i mindre batterier. Idén grundar sig bland annat i att åldring av batterier ofta är en primär begränsning för funktionen hos fristående solcellssystem.

    Studien, som till stor del är en sammanställning av vetenskapliga artiklar, syftar till att bidra med bättre grundläggande förståelse för hur pulsad laddning verkar på bly-syra batterier och deras elektrokemi. I synnerhet har grundläggande skillnader mellan större öppna batterier och mindre slutna batterier pekats ut, och ett antal parametrar som bestämmer pulsprocessens verkan identifierarats; frekvens, pulsspänning och laddningsgrad.

    Förhoppningen är att den mer teoretiska sammanställningen i förlängningen skall kunna bidra till att de företag i regionen som arbetar med denna teknik kan optimera funktionen i sina produkter.

    För att kunna säkra funktionen hos ett batteri så måste man kunna bedöma batteriets hälsotillstånd, och identifiera degradering på ett relativt tidigt stadium. En andra del av förstudien berör därför möjliga tillvägagångsätt att via mätningar på batteriets två poler kunna bestämma dess hälsotillstånd – och framförallt peka på de begränsningar dessa metoder har. Syftet är att bidra med grunden till en eventuell utveckling av ett enkelt batteriövervakningssystem som skall kunna ge användaren en tydlig och tidig signal om att det är dags för service. Sannolikt krävs det att man mäter en kombination av flertalet parametrar för att kunna åstadkomma detta, och i synnerhet blir förutsättningarna bättre om parametrar kan loggas över tid.

    Sammanfattningsvis diskuteras i mer övergripande och spekulativa ordalag den utmaning som den brokiga samling mindre batteri i många utvecklingsländer innebär. För att trygga funktionen behöver en organisation för batteriservice med kunniga tekniker byggas upp tillsammans med tekniska produkter för exempelvis övervakning.

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