Load and Season Adapted Solar Collectors

In Sweden solar irradiation and space heating loads are unevenly distributed over the year. Domestic hot water loads may be nearly constant. Test results on solar collector performance are often reported as yearly output of a certain collector at fixed temperatures, e g 25, 50 and 75 C. These data are not suitable for dimensioning of solar systems, because the actual performance of the collector depends heavily on solar fraction and load distribution over the year.At higher latitudes it is difficult to attain high solar fractions for buildings, due to overheating in summer and small marginal output for added collector area. Solar collectors with internal reflectors offer possibilities to evade overheating problems and deliver more energy at seasons when the load is higher. There are methods for estimating the yearly angular irradiation distribution, but there is a lack of methods for describing the load and the storage in such a way as to enable optical design of season and load adapted collectors.This report describes two methods for estimation of solar system performance with relevance for season and load adaption. Results regarding attainable solar fractions as a function of collector features, load profiles, load levels and storage characteristics are reported. The first method uses monthly collector output data at fixed temperatures from the simulation program MINSUN for estimating solar fractions for different load profiles and load levels. The load level is defined as estimated yearly collector output at constant collector temperature divided be yearly load. This table may examplify the results:CollectorLoadLoadSolar Improvementtypeprofile levelfractionover flat plateFlat plateDHW 75 %59 %Load adaptedDHW 75 %66 %12 %Flat plateSpace heating 50 %22 %Load adaptedSpace heating 50 %28 %29 %The second method utilises simulations with one-hour timesteps for collectors connected to a simplified storage and a variable load. Collector output, optical and thermal losses, heat overproduction, load level and storage temperature are presented as functions of solar incidence angles. These data are suitable for optical design of load adapted solar collectors. Results for a Stockholm location indicate that a solar combisystem with a solar fraction around 30 % should have collectors that reduce heat production at solar heights above 30 degrees and have optimum efficiency for solar heights between 8 and 30 degrees.

Competitive Solar Heating Systems for Residential Buildings (REBUS)

Research on solar combisystems for the Nordic and Baltic countries have been carriedout. The aim was to develop competitive solar combisystems which are attractive tobuyers and to educate experts in the solar heating field.The participants of the projects were the universities: Technical University of Denmark,Dalarna University, University of Oslo, Riga Technical University and Lund Institute ofTechnology, as well as the companies: Metro Therm A/S (Denmark), Velux A/S(Denmark), Solentek AB (Sweden), SolarNor (Norway) and SIA Grandeg (Latvia).The project included education, research, development and demonstration. Theactivities started in 2003 and were finished by the end of 2006. A number of Ph.D.studies in Denmark, Sweden and Latvia, and a post-doc. study in Norway were carriedout. Close cooperation between the researchers and the industry partners ensured thatthe results of the projects can be utilized. The industry partners will soon be able tobring the developed systems into the market.In Denmark and Norway the research and development focused on solarheating/natural gas systems, and in Sweden and Latvia the focus was on solarheating/pellet systems. Additionally, Lund Institute of Technology and University ofOslo studied solar collectors of various types being integrated into the building.

Solar thermal components adapted to common building standards (SCAS)

Pilot versions of a solar heating/natural gas burner system, of a solar heating/pellet burner system and of a façade/roof integrated polymeric collector have been installed in the summer of 2006 in a number of demonstration houses in Denmark, Sweden and Norway.These three new products have been evaluated by means of measurements of the thermal performance and energy savings of the pilot systems in practice and by means of a commercial evaluation.The conclusion of the evaluations is that the products are attractive for the industry partners METRO THERM A/S, Solentek and SOLARNOR. It is expected that the companies will bring the products into the market in 2007.Further, the results of the project have been presented atinternational and national congresses and seminars for the solar heating branch. The congresses and seminars attracted a lot of interested participants.Furthermore, the project results have been published in international congress papers as well as in national journals in the energy field.Consequently, the Nordic solar heating industry will benefit from the project.

A computational comparison of different algorithms for very large p-median problems

In this paper, we propose a new method for solving large scale p-median problem instances based on real data. We compare different approaches in terms of runtime, memory footprint and quality of solutions obtained. In order to test the different methods on real data, we introduce a new benchmark for the p-median problem based on real Swedish data. Because of the size of the problem addressed, up to 1938 candidate nodes, a number of algorithms, both exact and heuristic, are considered. We also propose an improved hybrid version of a genetic algorithm called impGA. Experiments show that impGA behaves as well as other methods for the standard set of medium-size problems taken from Beasley’s benchmark, but produces comparatively good results in terms of quality, runtime and memory footprint on our specific benchmark based on real Swedish data.

How to avoid Copenhagen : An experimental economic approach to climate negotiations

This study got its origin in the failed climate negotiations in the Copenhagen 2009 summit. By conducting a public good game, with participants from China and Sweden, my study indicates that previous studies on public good games can predict the outcome of the game to a quit large extent even though most of my statistical tests came out statistically insignificant. My study also indicates that by framing the game as climate negotiations there were no statistical significant difference on the level of contributions in comparison to the unframed versions of the game. The awareness of the issues with emissions, global warming and other environmental problems are pretty high but even so when push comes to shove gains in the short run are prioritized to gains in the long run. There are however hypothetical willingness to come to term with the environmental issues. The results of the study indicate that the outcome of the Copenhagen summit can be avoidable but would need additional experiments made on cultural differences and behavior.

Integration eller illusion : et deviance-perspektiv

Integration or illusion – a deviance perspective Denmark experienced one of its most successful periods of economic growth in 2004– 2008 with a tremendous reduction of unemployment, which in June 2008 was around. 1.5 percent, far below the expected level of structural unemployment. In the wake of this development the lack of utilization of migrants’ educations and skills became, once again, a core concern. The political, societal and academic debate followed to a great extent the traditional top-down approach to the problem and revolved around two axes: 1. How effective the labour market was/is to make use of migrants’ skills. 2. Whether there were patterns of over-education as expression of institutional and societal discrimination. The focus of the present study is, however, quite different: We examine the pattern of deviance in relation to labour market participation (not integration), and instead of searching for explanations for the lack of integration, we attempt to identify and explain the deviance pattern as a product of institutionally inherent possibilities and barriers on the one hand and articulating immigrants as rational actors (not victims) on the other. We argue that deviance is not only a more fruitful theoretical and analytical framework than integration and discrimination. Taking departure in empirical evidence on immigrants’ preferences and behaviour as bounded rational actors, and how they actually articulate their everyday life practical experiences, including adjustment of what they want and what they can, the deviance perspective, we believe, also reduces the theoretical and normative biases, that characterises the discrimination and integration framework, and provide more reliable explanations. 

Hjælp til selvcensur

Self-help and self-censorship: A self-help cultural perspective on organizational silence This paper seeks to explain silence in the workplace through an analytical perspective derived from Judith Butlers work on censorship, and in this way suggest an alternative to explanations in the existing literature on employee silence, which are often tied to the actions and motivations of the individual subject. It is thus argued that self-help books can be seen as indicative of a pervasive culture of self-improvement, which among other things promotes the absence of criticism in the workplace. The empirical point of departure for this argument is the two bestselling self-help books The secret by Rhonda Byrne and The 7 habits of highly effective people by Stephen Covey. Theoretically, the paper applies Butlers notion of ”implicit censorship” where censorship is understood as productive in the sense of being constitutive of language. Hence, in the analysis it is shown how discursive regimes in self-help literature tend to be constructed in such a way, that explicit criticism cannot emerge as a meaningful activity, and is thus implicitly censored.

Forskningscirklar - en arena där lärares syn på vad deras arbete resulterar i kan utmanas. : Paper presented at NFPS:s conference in Copenhagen 7-9 March, 2003

Lärare kan i första hand antas bilda sig sin uppfattning om resultatet av sitt arbete genom vad de kan observera av det som sker med deras elever. Vad har då denna erfarenhetsbaserade kunskap för betydelse för hur de uppfattar sitt arbete? I Sverige har t ex forskningscirklar använts i skolan, där lärare arbetar tillsammans med forskare, för att bearbeta frågeställningar som lärare möter i sin vardag. Kan forskningscirklar då vara ett sätt att utmana lärares syn på vilka resultat som deras arbete leder till?Från dessa utgångspunkter förefaller det vara relevant att ställa frågan om dessa sk forskningscirklar också kan vara en mötesplats där lärares syn på vilka resultat som deras arbete leder till utmanas? Följande frågeställning formuleras:• På vilken utsträckning kan forskningscirklar fungera som ett sätt att öppna nya infallsvinklar på hur lärare ser på resultatet av sitt arbete?

Från traditionellt akademiskt bibliotek till modern lärmiljö : Högskolan Dalarnas bibliotek – förväntningar och resultat

I denna rapport beskrivs idéerna bakom Högskolan Dalarnas prisbelönta bibliotek i Falun. Planerings- och byggprocessen beskrivs och det färdiga resultatet utvärderas, samt de erfarenheter som har gjorts delas.

Where do e-Government strategies take the Nordic nations?

An effective strategy is critical for the successful development of e-Government. The leading nations in the e-Government rankings include Sweden, Norway, Denmark and Finland. Their leading role makes them interesting to study when looking for reasons to successful e-Government. The purpose of this research paper is to describe the e-Government development strategies of Nordic countries, which rank highly on the international stage. In particular it aims to study the foci of these strategies. The approach is a document study of the e-Government development strategies of Sweden, Denmark, Norway and Finland was carried out using a qualitative content analysis inductive method. The results show that the major focus of Nordic e-Government strategies is on public sector reforms. Other focus areas include economic reforms and, to a lesser extent, e-Democracy efforts. Sweden, Finland and Norway have set ambitious policy goals in order to achieve global leadership in e-Government development. In response to the question posed by this paper’s title, we can say that Nordic e-Government strategies, except for Norway, focus more on reforming public sector services than on economic reforms.  E-Democracy reforms are hardly focused on at all. Practical implications: Public sector policy makers can relate their policy foci to some of the more successful e-Government countries in the world. Research implications/originality is that this paper can apart from the findings also provide a means on how to identify the actual foci of a country’s e-Government policy.

Sociala kartor över utbildningslandskapet : Installationsföreläsning, professuren i utbildningssociologi vid Uppsala universitet, 11 november 2015

Sociologisk Forsknings digitala arkiv