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  • 1.
    Carlsson, Bo
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Persson, Helena
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Meir, Michaela
    Aventa AS, Norway.
    Rekstad, John
    University of Oslo, Norway.
    A total cost perspective on use of polymeric materials in solar collectors - Importance of environmental performance on suitability2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 125, p. 10-20Article in journal (Refereed)
    Abstract [en]

    To assess the suitability of solar collector systems in which polymeric materials are used versus those in which more traditional materials are used, a case study was undertaken. In this case study a solar heating system with polymeric solar collectors was compared with two equivalent but more traditional solar heating systems: one with flat plate solar collectors and one with evacuated tube solar collectors. To make the comparison, a total cost accounting approach was adopted. The life cycle assessment (LCA) results clearly indicated that the polymeric solar collector system is the best as regards climatic and environmental performance when they are expressed in terms of the IPPC 100 a indicator and the Ecoindicator99, H/A indicator, respectively. In terms of climatic and environmental costs per amount of solar heat collected, the differences between the three kinds of collector systems were small when compared with existing energy prices. With the present tax rates, it seems unlikely that the differences in environmental and climatic costs will have any significant influence on which system is the most favoured, from a total cost point of view. In the choice between a renewable heat source and a heat source based on the use of a fossil fuel, the conclusion was that for climatic performance to be an important economic factor, the tax or trade rate of carbon dioxide emissions must be increased significantly, given the initial EU carbon dioxide emission trade rate. The rate would need to be at least of the same order of magnitude as the general carbon dioxide emission tax rate used in Sweden. If environmental costs took into account not only the greenhouse effect but also other mechanisms for damaging the environment as, for example, the environmental impact factor Ecoindicator99 does, the viability of solar heating versus that of a natural gas heating system would be much higher.

  • 2.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Life cycle primary energy use and carbon footprint of wood-frame conventional and passive houses with biomass-based energy supply2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, p. 834-842Article in journal (Refereed)
    Abstract [en]

    In this study the primary energy use and carbon footprint over the life cycle of a wood-frame apartmentbuilding designed either conventionally or to the passive house standard are analyzed. Scenarioswhere the building is heated with electric resistance heaters, bedrock heat pump or cogeneration-baseddistrict heat, all with biomass-based energy supply, are compared. The analysis covers all life cyclephases of the buildings, including extraction of raw materials, processing of raw materials into buildingmaterials, fabrication and assembly of materials into a ready building, operation and use of the buildings,and the demolition of the buildings and the post-use management of the building materials. Theprimary energy analysis encompasses the entire energy chains from the extraction of natural resourcesto the delivered energy services. The carbon footprint accounting includes fossil fuel emissions, cementprocess reaction emissions, potential avoided fossil fuel emissions due to biomass residues substitutionand end-of-life benefit of post-use materials. The results show that the operation of the buildingaccounts for the largest share of life cycle primary energy use. The passive house design reduces theprimary energy use and CO2 emission for heating, and the significance of this reduction depends onthe type of heating and energy supply systems. The choice of end-use heating system strongly influencesthe life cycle impacts. A biomass-based system with cogeneration of district heat and electricitygives low primary energy use and low carbon footprint, even with a conventional design. The amountof biomass residues from the wood products chain is large and can be used to substitute fossil fuels.This significantly reduces the net carbon footprint for both the conventional and passive house designs.This study shows the importance of adopting a life cycle perspective involving production, construction,operation, end-of-life, and energy supply when evaluating the primary energy use and climaticimpacts of both passive and conventional buildings.

  • 3.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering. Mittuniversitetet, Östersund.
    Gustavsson, Leif
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Sathre, Roger
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Effect of thermal mass on life cycle primary energy balances of a concrete- and a wood-frame building2012In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 92, p. 462-472Article in journal (Refereed)
    Abstract [en]

    In this study we analyze the effect of thermal mass on space heating energy use and life cycle primary energy balances of a concrete- and a wood-frame building. The analysis includes primary energy use during the production, operation, and end-of-life phases. Based on hour-by-hour dynamic modeling of heat flows in building mass configurations we calculate the energy saving benefits of thermal mass during the operation phase of the buildings. Our results indicate that the energy savings due to thermal mass is small and varies with the climatic location and energy efficiency levels of the buildings. A concrete-frame building has slightly lower space heating demand than a wood-frame alternative, due to the higher thermal mass of concrete-based materials. Still, a wood-frame building has a lower life cycle primary energy balance than a concrete-frame alternative. This is due primarily to the lower production primary energy use and greater bioenergy recovery benefits of the wood-frame buildings. These advantages outweigh the energy saving benefits of thermal mass. We conclude that the influence of thermal mass on space heating energy use for buildings located in Nordic climate is small and that wood-frame buildings with cogeneration based district heating would be an effective means of reducing primary energy use in the built environment.

  • 4.
    Gustavsson, Leif
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Eriksson, Lisa
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Sathre, Roger
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Costs and CO2 benefits of recovering, refining and transporting logging residues for fossil fuel replacement2011In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, no 1, p. 192-197Article in journal (Refereed)
    Abstract [en]

    There are many possible systems for recovering, refining, and transporting logging residues for use as fuel. Here we analyse costs, primary energy and CO2 benefits of various systems for using logging residues locally, nationally or internationally. The recovery systems we consider are a bundle system and a traditional chip system in a Nordic context. We also consider various transport modes and distances, refining the residues into pellets, and replacing different fossil fuels. Compressing of bundles entails costs, but the cost of chipping is greatly reduced if chipping is done on a large scale, providing an overall cost-effective system. The bundle system entails greater primary energy use, but its lower dry-matter losses mean that more biomass per hectare can be extracted from the harvest site. Thus, the potential replacement of fossil fuels per hectare of harvest area is greater with the bundle system than with the chip system. The fuel-cycle reduction of CO2 emissions per harvest area when logging residues replace fossil fuels depends more on the type of fossil fuel replaced, the logging residues recovery system used and the refining of the residues, than on whether the residues are transported to local, national or international end-users. The mode and distance of the transport system has a minor impact on the CO2 emission balance.

  • 5.
    Gustavsson, Leif
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Haus, Sylvia
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Ortiz, Carina A.
    Swedish University of Agricultural Sciences.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Truong, Nguyen Le
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Climate effects of bioenergy from forest residues in comparison to fossil energy2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 138, p. 36-50Article in journal (Refereed)
    Abstract [en]

    Forest residues can be left at the harvest site to gradually decompose, or can be collected for energy purposes. This study analyzes the primary energy and climate impacts of bioenergy systems where forest residues are collected and used for electricity, heat and transportation, compared to fossil-based energy systems where fossil fuels provide the same services while forest residues are left on site to decompose. Time profiles are elaborated of primary energy use and carbon dioxide emissions from various energy applications fulfilled by bioenergy or fossil energy systems. Different biological decay functions are considered based on process-based modeling and inventory data across various climate zones. For all scenarios, the changes in cumulative radiative forcing (CRF) are calculated over a 300-year period, to evaluate the short- and long-term contributions of forest residue to climate change mitigation. A life cycle perspective along the full energy chains is used to evaluate the overall effectiveness of each system. The results show largest primary energy and climate benefits when forest residues are collected and used efficiently for energy services. Using biomass to substitute fossil coal provides greater climate change mitigation benefits than substituting oil or fossil gas. Some bioenergy substitutions result in positive CRF, i.e. increased global warming, during an initial period. This occurs for relatively inefficient bioenergy conversion pathways to substitute less carbon intensive fossil fuels, e.g. biomotor fuel used to replace diesel. More beneficial bioenergy substitutions, such as efficiently replacing coal, result immediately in reduced CRF. Biomass decay rates and transportation distance have less influence on climate benefits.

  • 6.
    Hagos, Dejene Assefa
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology. Gjovik Univ Coll.
    Gebremedhin, Alemayehu
    Gjovik Univ Coll.
    Zethraeus, Björn
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Towards a flexible energy system - A case study for Inland Norway2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 130, p. 41-50Article in journal (Refereed)
    Abstract [en]

    This paper analyze the benefits of the use of bioenergy, solar thermal and wind energy in a flexible energy system to increase the share of renewable sources (RES) in primary energy supply, reduce primary energy consumption (PEC) and ensure power supply security in Inland Norway, and Norway at large. Firstly, the Inland reference energy system was built and validated using the EnergyPLAN system analysis tool based on the year 2009. Two alternative systems (scenarios), mainly of bio-heat and heat pumps in individual and district heating systems were then constructed and compared with the reference system using EnergyPLAN. The quality of a given energy system can be best described by its PEC, RES, emission levels and socio-economic costs. The result shows that it is plausible to improve the quality of the Inland energy system by optimal resource assortment in the energy mix. Integrated use of bin-heat and heat pumps in individual and district heating systems, as a replacement for direct electric heaters would reduce PEC and socio-economic costs considerably more than intensive bio-heating deployment alone, thereby increasing total domestic green electricity generation. The ability to integrate wind power and its value in the Inland energy system is more reflected by reducing imports of electricity during peak demand periods in winter, as wind power availability in the region is significant as opposed to the low precipitation during these periods. In addition, increasing wind energy penetration helps to limit biomass consumption in a district heating system built on heat pumps and bio-heat boilers. (C) 2014 Elsevier Ltd. All rights reserved.

  • 7.
    Joelsson, Anna
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Gustavsson, Leif
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    District heating and energy efficiency in detached houses of differing size and construction2009In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, no 2, p. 126-134Article in journal (Refereed)
    Abstract [en]

    House envelope measures and conversion of heating systems can reduce primary energy use and CO2 emission in the existing Swedish building stock. We analysed how the size and construction of electrically heated detached houses affect the potential for such measures and the potential for cogenerated district heating. Our starting point was two typical houses built in the 1970s. We altered the floor plans to obtain 6 houses, with heated floor space ranging between 100 and 306 m2. One of the houses was also analysed for three energy standards with differing heat loss rates. CO2 emission, primary energy use and heating cost were estimated after implementing house envelope measures, conversions to other heating systems and changes in the generation of district heat and electricity. The study accounted for primary energy, including energy chains from natural resources to useful heat in the houses. We showed that conversion to district heating based on biomass, together with house envelope measures, reduced the primary energy use by 88% and the CO2 emission by 96%, while reducing the annual societal cost by 7%. The choice of end-use heating system was decisive for the primary energy use, with district heating being the most efficient. Neither house size nor energy standard did significantly change the ranking of the heating systems, either from a primary energy or an economic viewpoint, but did affect the extent of the annual cost reduction after implementing the measures.

  • 8.
    Lin, Leteng
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Strand, Michael
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Investigation of the intrinsic CO2 gasification kinetics of biomass char at medium to high temperatures2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 109, no SI, p. 220-228Article in journal (Refereed)
    Abstract [en]

    In total eight char samples from pelletized wood, miscanthus, and straw were prepared under various pyrolysis conditions. The CO2 gasification kinetics for each sample was established in the temperature range from 800 °C to 1300 °C by the combination of thermogravimetric analysis (TGA) and a novel aerosol-based method. The aerosol-based method was used for the high temperature range between 1100 °C and 1300 °C, by gasifying suspended char particles (0.5–10 μm) in an oxidizing carrier gas. A tapered element oscillating microbalance (TEOM) was used to measure the change of mass concentrations of particles in the carrier gas, before and after gasification. The results showed that the aerosol-based method could be used to investigate the intrinsic gasification kinetics of biomass char, at least up to 1300 °C. All char samples showed similar reactivity in the low temperature range. However, above 1000 °C there were significant differences in reactivity, and at 1300 °C the conversion of the wood was in the order of 10 times faster than that of straw. The general char reactivity order in this study was wood > miscanthus > straw.

  • 9.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Energy use and CO2 emission of new residential buildings built under specific requirements: The case of Växjö municipality, Sweden2015In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 152, p. 31-38Article in journal (Refereed)
    Abstract [en]

    The Växjö municipality sets specific energy related requirements beyond the Swedish building code (BBR) when selling land for the construction of new residential buildings. The requirement for Östra Lugnet residential area was that all buildings must be connected to the local district heating network and installation of heat pumps was prohibited in developer-built group/row houses. This paper (a) analyzed if the energy use of the buildings fulfilled the requirements of the BBR and that of Växjö municipality, and (b) compared the primary energy use and CO2 emission from operation of the district heated buildings with hypothetical scenarios where only air-source or bedrock heat pumps were installed. Results showed that a significant proportion of the group/row houses did not fulfil the specific energy use requirements of the BBR and that of Växjö municipality. There were large variations between predicted and actual energy use. Using a marginal accounting approach, houses with district heating were found to have the lowest carbon emission. From this perspective it seems appropriate for Växjö municipality to set the requirement that new residential buildings in Östra Lugnet be connected to the local district heating network.

  • 10.
    Mahapatra, Krushna
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Gustavsson, Leif
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Influencing Swedish homeowners to adopt district heating system2009In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, no 2, p. 144-154Article in journal (Refereed)
    Abstract [en]

    Improved energy efficiency and greenhouse gas mitigation could be achieved by replacing resistance heaters with district heating system. In 2005, only about 8% of the Swedish detached houses had district heating system. The expansion of such systems largely depends on homeowners’ adoption decisions. And, to motivate homeowners to adopt district heating, it is essential to understand their decision-making process. In this context, in June 2005 we carried out a questionnaire survey of about 700 homeowners who lived in the city of Östersund in houses with resistance heaters (baseline survey). About 84% of the respondents did not intend to install a new heating system. Since then these homeowners were influenced by (a) an investment subsidy by the Swedish government to replace resistance heaters with district heating, a brine/water-based heat pump, or a biomass-based heating system and (b) a marketing campaign by the municipality-owned district heating company. This paper analyses how these two measures influenced about 78% of the homeowners to adopt the district heating system. For this purpose we carried out a follow-up survey of the same homeowners in December 2006 (resurvey). Results showed that the investment subsidy and the marketing campaign created a need among the homeowners to adopt a new heating system. The marketing campaign was successful in motivating them to adopt the district heating system. The marketing strategy by the district heating company corresponds to the results obtained in the baseline survey.

  • 11.
    Mahapatra, Krushna
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Haavik, Trond
    Segel As, Norway.
    Aabrekk, Synnøve
    Segel As, Norway.
    Svendsen, Svend
    Technical University of Denmark, Lyngby, Denmark.
    Vanhoutteghem, Lies
    Technical University of Denmark, Lyngby, Denmark.
    Paiho, Satu
    VTT, Finland.
    Ala-Juusela, Mia
    VTT, Finland.
    Business models for full service energy renovation of single family houses in Nordic countries2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 112, p. 1558-1565Article in journal (Refereed)
    Abstract [en]

    In Nordic countries significant primary energy saving potential exists in houses built before 1980. These old houses need to be renovated, which provides an opportunity for implementation of energy efficiency measures. However, there are several economic and market hindrances and the renovation markets are dominated by handicraft-based individual solutions. In this paper we have analyzed the opportunities for implementation of one-stop-shop business models where an overall contractor offers full-service renovation packages including consulting, independent energy audit, renovation work, follow-up (independent quality control and commissioning) and financing. A comparative assessment of emerging business models in the Nordic countries shows that different types of actors can provide such a service. Financing is included in some models. There are differences in how customers are contacted, while the similarities are on how the service is provided. Even though there is strong business potential for one-stop-shop energy renovation concept, still it has been somewhat difficult to start or run such a business. Various options to overcome the hindrances to promote energy efficient renovation of detached houses are discussed.

  • 12.
    Mondejar, Maria E.
    et al.
    Lund University.
    Ahlgren, Fredrik
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy.
    Thern, Marcus
    Linnaeus University, Faculty of Technology, Kalmar Maritime Academy. Lund University.
    Genrup, Magnus
    Lund University.
    Quasi-steady state simulation of an organic Rankine cycle for waste heat recovery in a passenger vessel2017In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 185, no Special Issue Part 2, p. 1324-1335Article in journal (Refereed)
    Abstract [en]

    In this work we present the quasi-steady state simulation of a regenerative organic Rankine cycle (ORC)integrated in a passenger vessel, over a standard round trip. The study case is the M/S Birka Stockholmcruise ship, which covers a daily route between Stockholm (Sweden) and Mariehamn (Finland).Experimental data of the exhaust gas temperatures, engine loads, and electricity demand on board werelogged over a period of four weeks. These data where used as inputs for a simulation model of an ORC forwaste heat recovery of the exhaust gases. A quasi-steady state simulation was carried out on an offdesignmodel, based on optimized design conditions, to estimate the average net power production ofthe ship over a round trip. The maximum net power production of the ORC during the round trip wasestimated to supply approximately 22% of the total power demand on board. The results showed apotential for ORC as a solution for the maritime transport sector to accomplish the new and morerestrictive regulations on emissions, and to reduce the total fuel consumption.

  • 13.
    Nair, Gireesh
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Gustavsson, Leif
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Mahapatra, Krushna
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Owners perception on the adoption of building envelope energy efficiency measures in Swedish detached houses2010In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 87, no 7, p. 2411-2419Article in journal (Refereed)
    Abstract [en]

    The paper focuses on Swedish homeowners’ need for and perceptions about adopting building envelop energy efficiency measures. The paper is based on a questionnaire survey of 3059 homeowners (response rate of 36%) selected by stratified random sampling during the summer of 2008. The results showed that 70–90% of the respondents had no intention of adopting such a measure over the next 10 years. The main reasons for non-adoption were that homeowners were satisfied with the physical condition, thermal performance, and aesthetics of their existing building envelope components. A greater proportion of respondents perceived that improved attic insulation has more advantages than energy efficient windows and improved wall insulation, but windows were more likely to be installed than improved attic insulation. Respondents gave high priority to economic factors in deciding on an energy efficiency measure. Interpersonal sources, construction companies, installers, and energy advisers were important sources of information for homeowners as they planned to adopt building envelope energy efficiency measures. Policy measures to facilitate the rate of adoption of energy efficient building envelope measures are discussed.

  • 14.
    Nair, Gireesh
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustavsson, Leif
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Implementation of energy efficient windows in Swedish single-family houses2012In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 89, no 1, p. 329-338Article in journal (Refereed)
    Abstract [en]

    A questionnaire survey of 1010 homeowners in Jämtland and Västernorrland, which are two counties in central Sweden, was conducted to understand the factors influencing their decision to install energy-efficient windows. We complemented this survey with an interview of 12 window sellers/installers in the county Jämtland. The annual energy cost reduction, age, and condition of the windows were the most important reasons for the window replacement decision. Approximately 80% of the respondents replaced their windows with energy-efficient windows with U-value of 1.2 W/m2 K. Condensation problems, perceived higher prices, and lack of awareness about windows with lower U-values were important reasons for non-adoption of more energy-efficient windows. Window sellers/installers have a strong influence on homeowners’ window selection that was indicated by the 97% of homeowners who bought the windows that were recommended to them. Sellers/installers revealed that they did not recommend windows with U-value of less than 1.2 W/m2 K because they thought that investing in such windows was not economical and because windows with U-value less than 1.2 W/m2 K could cause water condensation on the external surface of window pane.

  • 15.
    Sahlin, Ullrika
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lubbe, Nils
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Benefits of biofuels in Sweden: A probabilistic re-assessment of the indexof new cars’ climate impact2011In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 92, p. 473-479Article in journal (Refereed)
    Abstract [en]

    The climate impact of new cars in Sweden 2009 has been evaluated by the Swedish Transport Administration. Their report takes into account reduction factors to attribute the positive impact of renewable fuels on CO2 emissions. The Swedish Transport Administration recommends the public to buy cars that can run on biofuels. Besides acknowledging prevailing uncertainties for many of the input parameters to the index of new cars’ climate impact, reduction factors are based on calculations from point estimates of input parameters. A probabilistic re-assessment of the index is presented to find out the importance of these uncertainties and to assess whether the point estimated recommendation might be misguiding. Probabilistic reduction factors for CO2 emissions were derived with the same deterministic model proposed by the Swedish Transport Administration, were Bayesian probability distributions or intervals assigned by expert judgements were used to describe uncertainty in the model input parameters. The use of biofuels most likely reduces CO2 emissions. Probabilistic modelling indicated a CO2 reduction for E85 as a fuel of 30% (95% credibility interval = 10–52%) in the same order as the 20% given by the Swedish Transport Administration. The best estimate of 28% decrease for gas cars (95% credibility interval = 3–44%) and is lower than the originally proposed reduction of 42%, but still within a similar range. The difference is due to the large extent of optimistic values used in the assessment by the Swedish Transport Administration. The CO2 emissions from the production of the biofuel had most influence on the model results. We conclude that the recommendation of the Swedish Transport Administration to consumers is still valid after probabilistic recalculation.

  • 16.
    Sathre, Roger
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Gustavsson, Leif
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Using wood products to mitigate climate change: External costs and structural change2009In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 86, no 2, p. 251-257Article in journal (Refereed)
    Abstract [en]

    In this study we examine the use of wood products as a means to mitigate climate change. We describe the life cycle of wood products including forest growth, wood harvest and processing, and product use and disposal, focusing on the multiple roles of wood as both material and fuel. We present a comparative case study of a building constructed with either a wood or a reinforced concrete frame. We find that the production of wood building material uses less energy and emits less carbon than the production of reinforced concrete material. We compare the relative cost of the two building methods without environmental taxation, under the current Swedish industrial energy taxation regime, and in scenarios that incorporate estimates of the full social cost of carbon emission. We find that the inclusion of climate-related external costs improves the economic standing of wood construction vis-à-vis concrete construction. We conclude that policy instruments that internalise the external costs of carbon emission should tend to encourage a structural change toward the increased use of sustainably produced wood products.

  • 17.
    Truong, Nguyen Le
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Dodoo, Ambrose
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Effects of heat and electricity saving measures in district-heated multistory residential buildings2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 118, p. 57-67Article in journal (Refereed)
    Abstract [en]

    The effects of heat and electricity saving measures in district-heated buildings can be complex because these depend not only on how energy is used on the demand side but also on how energy is provided from the supply side. In this study, we analyze the effects of heat and electricity saving measures in multistory concrete-framed and wood-framed versions of an existing district-heated building and examine the impacts of the reduced energy demand on different district heat (DH) production configurations. The energy saving measures considered are for domestic hot water reduction, building thermal envelope improvement, ventilation heat recovery (VHR), and household electricity savings. Our analysis is based on a measured heat load profile of an existing DH production system in Växjö, Sweden. Based on the measured heat load profile, we model three minimum-cost DH production system using plausible environmental and socio-political scenarios. Then, we investigate the primary energy implications of the energy saving measures applied to the two versions of the existing building, taking into account the changed DH demand, changed cogenerated electricity, and changed electricity use due to heat and electricity saving measures. Our results show that the difference between the final and primary energy savings of the concrete-framed and wood-framed versions of the case-study building is minor. The primary energy efficiency of the energy saving measures depends on the type of measure and on the composition of the DH production system. Of the various energy saving measures explored, electricity savings give the highest primary energy savings for the building versions. In contrast to the other heat savings measures, VHR gives lower primary energy savings as it also increases electricity demand. Primary energy savings for the building versions are lower where the minimum-cost DH production system includes cogeneration unit compared to where the minimum-cost DH production system comprises heat-only boilers. The primary energy savings are mainly from peak and medium-load boilers even though these production units cover a small share of the total DH production. This study shows that it is essential to consider the interaction between end-use energy saving measures and supply systems for district-heated buildings, to estimate the primary energy efficiency of energy saving measures.

  • 18.
    Truong, Nguyen Le
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Cost and primary energy efficiency of small-scale district heating systems2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 130, no Part 1 Special Issue, p. 419-427Article in journal (Refereed)
    Abstract [en]

    Efficient district heat production systems (DHS) can contribute to achieving environmental targets and energy security for countries that have demands for space and water heating. The optimal options for a DHS vary with the environmental and social-political contexts and the scale of district heat production, which further depends on the size of the community served and the local climatic conditions. In this study, we design a small-scale, minimum-cost DHS that produces approximately 100 GWhheat per year and estimate the yearly production cost and primary energy use of this system. We consider conventional technologies, such as heat-only boilers, electric heat pumps and combined heat and power (CHP) units, as well as emerging technologies, such as biomass-based organic Rankine cycle (BORC) and solar water heating (SWH). We explore how different environmental and social-political situations influence the design of a minimum-cost DHS and consider both proven and potential technologies for small-scale applications. Our calculations are based on the real heat load duration curve for a town in southern Sweden. We find that the district heat production cost increases and that the potential for cogeneration decreases with smaller district heat production systems. Although the selection of technologies for a minimum-cost DHS depends on environmental and social-political contexts, fewer technical options are suitable for small-scale systems. Emerging technologies such as CHP-BORC and SWH improve the efficiency of primary energy use for heat production, but these technologies are more costly than conventional heat-only boilers. However, systems with combined technologies are less sensitive to fluctuations in fuel prices, specifically the SWH system, compared to technologies based on conventional fuels. Furthermore, increased market penetration of SWH will reduce the investment costs of such systems and, along with expected fuel price increases, using SWH may be cost-efficient in DHSs.

  • 19.
    Truong, Nguyen Le
    et al.
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Building and Energy Technology.
    Integrated biomass-based production of district heat, electricity, motor fuels and pellets of different scales2013In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 104, p. 623-632Article in journal (Refereed)
    Abstract [en]

    Woody biomass can be used in different ways to contribute to sustainable development. In this paper, we analyze biomass-based production of district heat, electricity, pellets and motor fuels. We calculate production cost and biomass use of products from standalone production and from different district heat production options, including only heat production and various co/polygeneration options. We optimize the different district heat production systems considering the value of co/polygenerated products, other than district heat, as equal to those produced in minimum-cost standalone plants. Also, we investigate how the scale of district heating systems influences the minimum-cost composition of production units and district heat production costs. We find that co/polygenerated district heat is more cost and fuel efficient than that from heat-only production. Also, coproduction of electricity is more efficient than of motor fuels except for dimethyl-ether production in large district heat production systems. However, the cost difference is minor between coproduction of dimethyl-ether or electricity in such systems. Integrated biopellet production increases the production of electricity or motor fuel and reduces the production cost. District heat production cost depends on fuel price, however, its dependence is reduced if district heat production system is cost-minimized and based on co/polygenerated units. Also, the optimal composition and cost of district heat production depend on the scale of the system. The demand for biopellets may limit the potential integrated production of such a product. (C) 2012 Elsevier Ltd. All rights reserved.

  • 20.
    Truong, Nguyen Le
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Minimum-cost district heat production systems of different sizes under different environmental and social cost scenarios2014In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 136, p. 881-893Article in journal (Refereed)
    Abstract [en]

    District heat systems can contribute to the achievement of social and environmental targets and energy security. District heat production systems (DHSs) vary in size depending on heat demand, which is influenced by several factors such as local climatic conditions and the sizes of the communities they serve. In this study, we analyzed options for minimum-cost DHSs of different sizes under different environmental and social cost scenarios. We calculated the production cost and primary energy use of district heat for minimum-cost options by considering a value of cogenerated electricity equivalent to the value of electricity produced in minimum-cost standalone condensing power plants. We varied the size of DHSs from 100 to 1800 GWhheat per year to investigate how size influences the minimum-cost compositions of production units and district heat production costs. We determined that the optimal composition and cost of district heat production is dependent on the size of the system, the overall load factor of heat demand and the technologies considered for both DHSs and reference power plants. In general, cogenerated district heat is more energy-efficient than district heat from heat-only production and also more cost-efficient, except for small DHSs, for which cogenerated district heat is more costly than heat-only production. The cost and primary energy use of district heat production is dependent on environmental and social cost scenarios; however, this dependence is reduced if a DHS is cost-minimized and based on cogenerated units.

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