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  • 1.
    Bales, Chris
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Lindberg, Eva
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Fiedler, Frank
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    European Solar Engineering School ESES: Past and Future2006In: Eurosun 2006, Glasgow, Scotland, 2006Conference paper (Other academic)
    Abstract [en]

    The European Solar Engineering School ESES is a one-year masters program that started in 1999 at the Solar Energy Research Center SERC, Dalarna University College. It has been growing in popularity over the years, with over 20 students in the current year. Approximately half the students come from Europe, the rest coming from all over the globe. This paper described the contents and experiences from seven years of running the programme and the plans for adapting the programme to the Bologna process. 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.

  • 2. Bergkvist, Mikael
    et al.
    Hellström, Bengt
    Wäckelgård, Eva
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Platzer, Werner
    Jönsson, Bengt
    Perers, Bengt
    Karlsson, Björn
    Radical improvements of large collector fields1992In: North Sun, Trondheim, Norge, 1992Conference paper (Other academic)
  • 3. Brogren, Maria
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Karlsson, Björn
    PV-thermal hybrid low-concentrating CPC module2000In: 16:th EU PV conference, Glasgow, Scotland, 2000Conference paper (Other academic)
  • 4.
    Broman, Lars
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Lindberg, Eva
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rapport ramprogram FOU 1993-96, Projektnr 930391-05 samt förslag till ramprogram solfångarutveckling och systemteknik FOU 1997-99 solfångarutveckling och systemteknik1997Report (Other academic)
  • 5.
    Broman, Lars
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Broman, Arne
    Nordlander, Svante
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Analysis of four different solar corner concentrators1987In: Applied Optics in Solar Energy, Prague, Czechoslovakia, 1987Conference paper (Other academic)
  • 6. 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)
  • 7. 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)
  • 8. 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)
  • 9.
    Broman, Lars
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, MatsDalarna University, School of Technology and Business Studies, Environmental Engineering.
    Proceedings of International Conference North Sun '881999Book (Other academic)
  • 10.
    Broman, Lars
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Binder, Betty
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Lindberg, Eva
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Use of nonimaging concentrators for moderate concentration of sunlight onto PV cells1989In: 9thy European Photovoltaics Solar Energy Conference, Freiburg, Tyskland, 1989Conference paper (Refereed)
    Abstract [en]

    The square cornet type nonimaging concentrator has been shown useful for moderate concentration of sunlight onto photovoltaic solar cells, since it creates no hot spots at the exit aperture. In this paper are presented the mathematical formulas on which the cornet designs are based, results from computer simulations on overall cornet performance compared with measurements as well as exit aperture intensity variations, measured optical concentration ratios under controlled circumstances, and cell temperature measurements under realistic circumstances. In an Appendix are given performance curves for a large number of cornets as determined from computer simulations, covering the useful range of concentration factors and acceptance angles.

  • 11.
    Broman, Lars
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Karlsson, Björn
    Bergkvist, Mikael
    Wäckelgård, Eva
    Use of an integrating sphere for transmittance measurements on nonimaging concentrators1989In: North Sun´88, Borlänge, 1989Conference paper (Other academic)
  • 12.
    Broman, Lars
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Analysis of a possible perfect nonimaging concentrator1986In: North Sun´86, Copenhagen, Denmark, 1986Conference paper (Other academic)
  • 13.
    Broman, Lars
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Sallah, S.O.A.
    On the role of solar electricity in rural development1987In: ISES Solar World Congress, Hamburg, 1987Conference paper (Other academic)
  • 14. 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.

  • 15. Gustafsson, M.
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Trygg, L.
    Karlsson, B.
    CO2 emission evaluation of energy conserving measures in buildings connected to a district heating system: Case study of a multi-dwelling building in Sweden2016In: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 111, p. 341-350Article in journal (Refereed)
    Abstract [en]

    When taking action to fulfill the directives from the European Union, energy conserving measures will be implemented in the building sector. If buildings are connected to district heating systems, a reduced heat demand will influence the electricity production if the reduced heat demand is covered by combined heat and power plants.This study analyze five different energy conserving measures in a multi-dwelling building regarding how they affect the marginal production units in the district heating system in Gävle, Sweden. For CO2 emission evaluations, two different combinations of heat and electricity conserving measures are compared to an installation of an exhaust air heat pump.The different energy conserving measures affect the district heating system in different ways. The results show that installing an exhaust air heat pump affects the use/production of electricity in the district heating system most and electricity conserving measures result in reduced use of electricity in the building, reduced use of electricity for production of heat in the district heating system and an increase of electricity production.The conclusion is that electricity use in the building is the most important factor to consider when energy conserving measures are introduced in buildings within the district heating system in Gävle.

  • 16.
    Gustafsson, Mattias
    et al.
    Högskolan i Gävle.
    Karlsson, Björn
    Högskolan i Gävle.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    How the electric meter configuration affect the monitored amount of self-consumed and produced excess electricity from PV systems: case study in Sweden2017In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 138, p. 60-68Article in journal (Refereed)
    Abstract [en]

    This study evaluates how the principal function of bi-directional electric meters affects the monitored amount of self-consumed and produced excess electricity for dwelling buildings connected to the grid by three phases. The electric meters momentarily record the sum of the phases or the phases individually and then summarize the recorded values to a suitable time period and is then collected by the grid owner. In Sweden, both electric meter configurations fulfill laws and regulations.

    The meter configuration affects the monitored distribution of self-consumed and produced excess electricity significantly for the investigated single-family house but is negligible for the investigated multi-dwelling buildings. The monitored self-consumed electricity produced by the PV installation for the single-family house varies between 24% and 55% depending on the configuration and how the inverter is installed for the investigated year. The difference in economic value for the produced electricity varies between 79.3 to 142 Euros.

    Due to the electric meter configuration, the profitability of PV systems will be different for identical single-family houses with identical conditions. This should be corrected for a well-functioning market. It is also important to decide how the configuration should be designed to ensure that different incentives and enablers results in desired effects.

  • 17. Helgesson, Anna
    et al.
    Karlsson, Björn
    Krohn, Peter
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    PV-Panel with an Overedge Reflector for Northern Sun Conditions2001In: North Sun, Leiden, The Netherlands, 2001Conference paper (Other academic)
  • 18.
    Huang, Pei
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Copertaro, Benedetta
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Zhang, Xingxing
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Shen, Jingchun
    Dalarna University, School of Technology and Business Studies, Construction.
    Löfgren, Isabelle
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Fahlen, Jan
    Andersson, Dan
    Svanfeldt, Mikael
    A review of data centers as prosumers in district energy systems: Renewable energy integration and waste heat reuse for district heating2019In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118Article in journal (Refereed)
    Abstract [en]

    As large energy prosumers in district energy systems, on the one hand, data centers consume a large amount of electricity to ensure the Information Technologies (IT) facilities, ancillary power supply and cooling systems work properly; on the other hand, data centers produce a large quantity of waste heat due to the high heat dissipation rates of the IT facilities. To date, a systematic review of data centers from the perspective of energy prosumers, which considers both integration of the upstream green energy supply and downstream waste heat reuse, is still lacking. As a result, the potentials for improving data centers’ performances are limited due to a lack of global optimization of the upstream renewable energy integration and downstream waste heat utilization. This study is intended to fill in this gap and provides such a review. In this regard, the advancements in different cooling techniques, integration of renewable energy and advanced controls, waste heat utilization and connections for district heating, real projects, performance metrics and economic, energy and environmental analyses are reviewed. Based on the enormous amount of research on data centers in district energy systems, it has been found that: (1) global controls, which can manage the upstream renewable production, data centers’ operation and waste heat generation and downstream waste heat utilization are still lacking; (2) regional climate studies represent an effective way to find the optimal integration of renewable energy and waste heat recovery technologies for improving the data centers’ energy efficiency; (3) the development of global energy metrics will help to appropriately quantify the data center performances.

  • 19. J, Wennerberg
    et al.
    J, Kessler
    J, Hedström
    L, Stolt
    B, Karlsson
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    CIGS thin film PV modules for low-concentrating systems2001In: Solar Energy, ISSN 0038-092X, E-ISSN 1471-1257, Vol. 69, p. 243-255Article in journal (Refereed)
  • 20.
    Joudi, Ali
    et al.
    Dalarna University, School of Technology and Business Studies, Energy Technology. SSAB Europe, Borlänge.
    Cehlin, Mathias
    Högskolan i Gävle.
    Svedung, Harald
    Dalarna University, School of Technology and Business Studies, Energy Technology. SSAB Europe, Borlänge.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy Technology.
    Moshfegh, Bahram
    Högskolan i Gävle.
    Numerical and experimental investigation of the influence of infrared reflective interior surfaces on building temperature distributions2017In: Indoor + Built Environment, ISSN 1420-326X, E-ISSN 1423-0070, Vol. 26, no 3, p. 355-367Article in journal (Refereed)
    Abstract [en]

    Radiative properties of interior surfaces can affect not only the building heat flux but also the indoor environment, the latter of which has not been thoroughly investigated. The aim of this study is to analyse the effect of surface emissivity on indoor air and surface temperature distributions in a test cabin with reflective interior surfaces. This was done by comparing experimental and simulation data of the test cabin with that of a normal cabin. This study employs transient computational fluid dynamics (CFD) using re-normalisation group (RNG) k–" model, surface-to-surface radiation model and an enhanced wall function. Boundary conditions were assigned to exterior surfaces under variable outdoor conditions. The numerical and the measurement results indicate that using interior reflective surfaces will affect the indoor air temperature distribution by increasing the vertical temperature gradient depending on the time of the day. CFD simulations with high spatial resolution results show increased interior surface temperature gradients consistent with the increased vertical air temperature gradient. The influence of reflective surfaces is potentially greater with higher indoor surface temperature asymmetry. The vertical indoor air temperature gradient and surface temperatures are important parameters for indoor thermal comfort.

  • 21.
    Joudi, Ali
    et al.
    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.
    Svedung, Harald
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Wäckelgård, Ewa
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Energy Efficient Buildings with Functional Steel Cladding2011In: World Renewable Energy Congress, Linköping, Sweden, 2011Conference paper (Refereed)
    Abstract [en]

    The aim of the study is to develop a model for the energy balance of buildings that includes the effect from the radiation properties of interior and exterior surfaces of the building envelope. As a first step we have used ice arenas as case study objects to investigate the importance of interior low emissivity surfaces. Measurements have been done in two ice arenas in the north part of Sweden, one with lower and one with higher ceiling emissivity. The results show that the low emissivity ceiling gives a much lower radiation temperature interacting with the ice under similar conditions. The dynamic modelling of the roof in ice arenas shows a similar dependence of the roof-to-ice heat flux and the ceiling emissivity. A second part of the study focus on how to realise paints with very low thermal emissivity to be used on interior building surfaces.

  • 22.
    Joudi, Ali
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Svedung, Harald
    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.
    Highly reflective coatings for interior and exterior steel cladding and the energy efficiency of buildings2011In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 12, p. 4655-4666Article in journal (Refereed)
    Abstract [en]

    The effect of surface heat-radiation properties of coil-coated steel cladding material on the energy efficiency of buildings in Nordic climate is addressed by parallel temperature and energy usage measurements in a series of test cabins with different exterior solar reflectivity and interior thermal reflectivity. During one year, a number of one- or two-week experiments with air conditioner cooling and electrical floor heating were made while logging air-, radiation- and surface temperatures, energy consumption and weather conditions. Measurements show significant energy savings in the test cabins by the use of high thermal reflectivity interior surfaces both during heating and cooling and a strongly reduced cooling demand by the use of high solar reflectivity exterior surfaces. Results are interpreted within the context of a steady-state energy flux model, to illuminate the importance of surface resistance properties (radiation and convective heat dissipation).

  • 23.
    Joudi, Ali
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Svedung, Harald
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology. SSAB EMEA.
    Cehlin, Mathias
    Building, Energy and Environmental Engineering, University of Gävle.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Reflective coatings for interior and exterior of buildings and improving thermal performance2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 103, p. 562-570Article in journal (Refereed)
    Abstract [en]

    The importance of reducing building energy usage and thriving for more energy efficient architectures, has nurtured creative solutions and smart choices of materials in the last few decades. Among those are optimizing surface optical properties for both interior and exterior claddings of the building. Development in the coil-coating steel industries has now made it possible to allocate correct optical properties for steel clad buildings with improved thermal performance. Although the importance of the exterior coating and solar gain are thoroughly studied in many literatures, the effect of interior cladding are less tackled, especially when considering a combination of both interior and exterior reflective coatings. This paper contemplates the thermal behavior of small cabins with reflective coatings on both interior and exterior cladding, under different conditions and climates with the aim to clarify and point out to the potential energy saving by smart choices of clad coatings.

  • 24.
    Joudi, Ali
    et al.
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    Svedung, Harald
    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.
    Energy efficient surfaces on building sandwich panels: a dynamic simulation model2011In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 43, no 12, p. 3736-3736Article in journal (Refereed)
    Abstract [en]

    The choice of building envelope is critical for the energy performance of buildings. The major part of the energy used by a building during its lifetime is used for maintaining a suitable interior thermal climate under varying exterior conditions. Although exterior heat radiation properties (i.e. total solar reflectivity and long wave thermal emissivity) have been well accepted to have a large impact on the need for active cooling in warmer climate, the effect of a reduced thermal emissivity on interior surfaces on the building thermal energy flux is rarely studied. This paper addresses the sensitivity of the thermal energy flux through a sandwich panel, by systematically varying the surface thermal emissivity (both interior and exterior) and total solar reflectance of exterior surface, for three geographical locations: southern, middle and northern Europe. A model is introduced for calculating the effect of both interior and exterior optical properties of a horizontal roof panel in terms of net energy flux per unit area. The results indicate potential energy saving by the smart choice of optical properties of interior and exterior surfaces.

  • 25. Karlsson, Björn
    et al.
    Helgesson, Anna
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Utveckling av moduler med överliggande refflektorer för fristående solcellssystem för årstidsutjämning och för att undvika snö och frostbeläggning2001Report (Other academic)
  • 26. Karlsson, Björn
    et al.
    Krohn, Peter
    Perers, Bengt
    Krohn, Peter
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Brogren, Maria
    Solceller med reflektorer: Resultat 19992000Report (Other academic)
  • 27. Karlsson, Björn
    et al.
    Krohn, Peter
    Perers, Bengt
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Solceller med reflektorer: Resultat 19971997Report (Other academic)
  • 28. Karlsson, Björn
    et al.
    Krohn, Peter
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Solceller med reflektorer: Resultat 19981998Report (Other academic)
  • 29. Kjellsson, E
    et al.
    Hellström, G
    Tepe, R
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Combination of Solar Heat and Ground Source Heat Pump for Small Buildings2003In: Futurestock 2003, Warsaw, 2003Conference paper (Other academic)
  • 30. 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.

  • 31.
    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.

  • 32.
    Mattsson Petersen, Cecilia
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Berg, Per E O
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Kartläggning av organiskt avfall2004Report (Other academic)
  • 33. 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)
  • 34. Nordlander, Svante
    et al.
    Persson, Tomas
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Fiedler, Frank
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Computer modelling of wood pellet stoves and boilers connected to solar heating systems2006In: Proc on USB of Pellets 2006, 30 May - 1 June, Jönköping, Sweden, Jönköping, Sweden, 2006Conference paper (Other academic)
    Abstract [en]

    When optimizing systems for wood pellet and solar heating, there is a need for realistic computer models of stoves and boilers in order to perform simulation studies. The objective of this work was to develop and verify a mathematical model for wood pellet stoves and boilers for use in system simulations with TRNSYS calculating both the energy balance and CO-emissions (carbon monoxide). Laboratory measurements have been carried out on three pellet stoves, one traditional and two with gas-liquid heat exchangers, and four pellet boilers. A mathematical two-node model of a stove was developed and implemented as a TRNSYS component. Parameters were identified for two stoves and three boilers. This new model makes it possible to perform detailed simulations with time steps less than a minute of complete wood pellet heating systems and to derive long term values, such as annual values, of efficiency and emissions for the boiler or stove in a system context under realistic conditions. In addition, parametric studies can be used in order to investigate how different operation principles and system design affect these values. The simulated energy balance of a water jacketed stove investigated in this work agreed well with measured data during both stationary and dynamic conditions.

  • 35. Nordlander, Svante
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Load Adapted Collectors for High Solar Fractions2001In: North Sun, Leiden, The Netherlands, 2001Conference paper (Other academic)
  • 36.
    Nordlander, Svante
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Solvärmesystem för hög täckningsgrad - Load adapted concentrating collectors for high solar fractions2004Report (Other academic)
    Abstract [sv]

    Dagens kombisolvärmesystem för enfamiljshus har i storleksordningen 10 m2 solfångare och kan täcka i runda tal 10 ? 30 % av det årliga värmebehovet. Ökar man solfångarytan för att öka solvärmetäckningsgraden uppstår det vanligtvis en överproduktion av värme sommartid viket kan orsaka problem i form av termisk utmattning av material, att material förstörs eller att säkerhetsventiler utlöses med driftsstopp som följd. Vidare förkortas glykolens livslängd radikalt och detta kan ge följdskador såsom korrosion, beläggningar i rören och t o m igensättning av systemet. Ett sätt att undvika problemen med överhettning i solvärmesystem med hög täckningsgrad är att använda lastanpassade solfångare. Med detta menas solfångare som har en verkningsgrad som är beroende av solhöjden och varierar över året. Verkningsgraden är hög när värmelasten är hög (vanligtvis sen höst, vinter och tidig vår) medan verkningsgraden är låg då värmelasten är låg (vanligtvis sen vår, sommar och tidig höst). I denna rapport visas att det är möjligt att bygga lastanpassade solfångarsystem med hög täckningsgrad för enfamiljshus med solfångarytor som täcker hela villatak (>= 40 m2), utan att den termiska påfrestningen på systemet blir större än för vanliga solvärmesystem med 10 m2 plana solfångare. Detta kan göras med samma systemkomponenter som finns i system med plana solfångare. De lastanpassade solfångarna levererar ungefär samma energimängd per m2 som plana solfångare, men de bör kunna bli billigare, på grund av lägre materialkostnad. Det finns även en potential att konstruera lastanpassade solvärmesystem med begränsad stagnationstemperatur, vilket kan möjliggöra användandet av billigare material. En och samma solfångartyp är lämplig för såväl stora som små system och för olika takvinklar. I rapporten redovisas optimerade solfångargeometrier för lastanpassade solvärmesystem, geometrier och optiska egenskaper för praktiskt möjliga solfångare samt beräkningar av förväntat årsutbyte, stagnationstemperaturer, stagnationstider och kostnader. Testresultat för två prototyper av lastanpassade solfångare presenteras. Optimeringsalgoritmer för design av optiken för lastanpassade solfångare i system samt ett ray-tracingverktyg och snabba men ändå tillräckligt noggranna simuleringsverktyg har utvecklats.

  • 37. Nordlander, Svante
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Broman, Lars
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Isakson, Per
    Figueroa, Eduardo
    PRESIM - a graphical interactive preprocessor for modular simulation programs1989In: North Sun´88, Borlänge, 1989Conference paper (Other academic)
  • 38. Nordlander, Svante
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Isakson, Per
    Broman, Lars
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Presentation of PRESIM - a user-friendly preprocesssor for TRNSYS1990In: North Sun´90, Reading, 1990Conference paper (Other academic)
  • 39. Nordlander, Svante
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Isakson, Per
    Broman, Lars
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Presentation of PRESIM. A userfriendly pre-processor for TRNSYS1991In: Nordic Solar Energy R & D Meeting, Borlänge, 1991Conference paper (Other academic)
  • 40.
    Nordlander, Svante
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Isakson, Per
    Broman, Lars
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    PRESIM - a graphical interactive preprocessor for modular simulation programs1989In: ISES Solar World Congress, Kobe, Japan, 1989Conference paper (Refereed)
    Abstract [en]

    PRESIM is a computer program for creating, storing, retrieving and changing input data for modular HVAC programs. The user works with CAD-style tools. The program also produces system schematics and other documentation. A first release of PRESIM will produce input data for the TRNSYS program.

  • 41. Nordlander, Svante
    et al.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Karlsson, Björn
    Load and Season Adapted Solar Collectors2000In: Eurosun 2000, Copenhagen, Denmark, 2000Conference paper (Other academic)
    Abstract [en]

    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: Collector Load Load Solar Improvement type profile level fraction over flat plate Flat plate DHW 75 % 59 % Load adapted DHW 75 % 66 % 12 % Flat plate Space heating 50 % 22 % Load adapted Space 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.

  • 42. Perers, Bengt
    et al.
    Karlsson, Björn
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    An improved Dynamic Test Method for the Determination of Non-Linear Incidence Angle Modifiers from Outdoor Testing using Standard Multiple Regression Tools1996In: EuroSun 1996, Freiburg, Germany, 1996Conference paper (Other academic)
  • 43.
    Perers, Bengt
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Lorenz, Klaus
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Partiell förångning i solfångarsystem: överhettningsskydd för värmebäraren (främst glykol)2003Report (Other academic)
  • 44. Perers, Bengt
    et al.
    Spante, Lars
    Krohn, P
    Setterwall, C
    Gröndalen, O
    Holmström, S
    Selhagen, L
    Sandell, P
    Andersson, M
    Stolt, L
    Wennerberg, J
    Sterner, J
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Forssander, M
    Sandberg, B
    Björk, D
    Solceller 19961996Report (Other academic)
  • 45.
    Persson, Tomas
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Fiedler, Frank
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Bales, Chris
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Increasing efficiency and decreasing CO-emissions for a combined solar and wood pellet heating system for single-family houses2006In: Proc. on USB of Pellets 2006, 30 May - 1 June, Jönköping, Sweden, Jönköping, Sweden, 2006Conference paper (Other academic)
    Abstract [en]

    This study focus on how wood pellets and solar heating systems for single-family houses should be designed and controlled to reach high efficiency and to reduce the CO-emissions. A recently developed TRNSYS model was used to simulate the wood pellet boiler. Parameters for the model were identified from laboratory measurements on a boiler. A detailed simulation model of a complete solar combisystem was created and annual simulations were performed. Assuming that all heat losses to the room are waist heat, the results show that the most important factors to achieve high system efficiency are that the boiler and the buffer store should be well insulated. The sensor controlling the boiler should be placed in the store; the pump between the boiler and the store should only be in operation together with the burner and for some time after the burner have stopped to take care of the after burning heat. For boilers with relatively large start and stop CO-emissions modulating power may be an efficient measure to reduce CO-emissions. Especially for boilers using an ON-OFF control, the dominating contribution of CO-emissions may be during the start and stop phases, thus reducing emissions during operation may have little influence on the annual CO-emissions.

  • 46.
    Persson, Tomas
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Nordlander, Svante
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Electrical savings by use of wood pellet stoves and solar heating systems in electrically heated single-family houses2005In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 37, no 9, p. 920-929Article in journal (Refereed)
    Abstract [en]

    This study investigates how electrically heated single-family houses can be converted to wood pellets- and solar heating using pellet stoves and solar heating systems. Four different system concepts are presented and system simulations in TRNSYS evaluate the thermal performance and the electrical savings possible for two different electrically heated single-family houses. Simulations show that the electricity savings using a wood pellet stove are greatly affected by the level of comfort, the house plan, the system choice and if the internal doors are open or closed. Installing a stove with a water-jacket connected to a radiator system and a hot water store has the advantage that heat can be transferred to domestic hot water and be distributed to other rooms. Such systems leads to that more electricity can be replaced, especially in houses having a traditional plan. Though it is unnecessary to have too many radiators connected to a stove with a low fraction of energy heating the water jacket. Today’s most common control strategy for stoves, (the on/off-control) results in unnecessarily high emissions. A more advanced control varying the heating rate from maximum to minimum to keep a constant room temperature reduces the number of starts and stops and thereby the emissions.

  • 47.
    Persson, Tomas
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Increasing solar gains by using hot water to heat dishwashers and washing machines2007In: Applied Thermal Engineering, ISSN 1359-4311, E-ISSN 1873-5606, Vol. 27, no 2-3, p. 646-657Article in journal (Refereed)
    Abstract [en]

    70 to 90% of the electric energy used by dishwashers and washing machines heats the water, the crockery, the laundry and the machine and could just as well be replaced by heating energy from solar collectors, district heating or a boiler. A dishwasher and a washing machine equipped with a heat exchanger and heated by a hot water circulation circuit instead of electricity (heat-fed machines) have been simulated together with solar heating systems for single-family houses in two different climates (Stockholm, Sweden and Miami, USA). The simulations show that a major part of the increased heat load due to heat-fed machines can be covered by solar heat both in hot and cold climates if the collector area is compensated for the larger heat load to give the same marginal contribution. Using ordinary machines connected to the hot water pipe (hot water-fed machines) and using only cold water for the rinses in the washing machine gives almost the same solar contribution; however considerably lower electrical energy savings are achieved. The simulations also indicate that improvements in the system design of a combisystem (increased stratification in the store) are more advantageous if heat-fed machines are connected to the store. Thus, using heat-fed machines also encourages the use of more advanced solar combisystems.

  • 48.
    Persson, Tomas
    et al.
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Increasing the solar gain by heat-fed and hot water-fed clothes washer and washing machines2006In: EuroSun 2006, Glasgow, UK, 2006Conference paper (Other academic)
    Abstract [en]

    70 to 90% of the electric energy used by dishwashers and washing machines heats the water, the crockery, the laundry and the machine and could just as well be replaced by heating energy from solar collectors, district heating or a boiler. A dishwasher and a washing machine equipped with a heat exchanger and heated by a hot water circulation circuit instead of electricity (heat-fed machines) have been simulated together with solar heating systems for single-family houses in two different climates (Stockholm, Sweden and Miami, USA). The increased heat load will increase the solar gain and this will compensate for the increased energy demand by heat-fed machines due to increased pipe losses and increased electricity used by pumps. Using ordinary machines connected to the hot water pipe (hot water-fed machines) and using only cold water for the rinses in the washing machine gives almost the same solar contribution; however considerably lower electrical energy savings are achieved since extra electricity is needed to heat up the machines to the required washing temperature.

  • 49.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Energy and Environmental Technology.
    En praktiker med ingenjörens systemkunnande - är det möjligt?2011In: Bioenergi - utmaningar och möjligheter / [ed] Dehlin, Karin; Persson, Lars; Wikström, Per-Arne, Gävle: Region Gävleborg , 2011, p. 53-56Chapter in book (Other academic)
  • 50.
    Rönnelid, Mats
    Dalarna University, School of Technology and Business Studies, Environmental Engineering.
    Enkla åtgärder kan öka solvärmeutbytet2004In: VVS & Installation, no oktoberArticle in journal (Other academic)
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