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Petrovic, B., Myhren, J. A., Zhang, X., Wallhagen, M. & Eriksson, O. (2019). Life cycle assessment of a wooden single-family house in Sweden. Applied Energy, 251, 113-253, Article ID 113253.
Open this publication in new window or tab >>Life cycle assessment of a wooden single-family house in Sweden
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2019 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 251, p. 113-253, article id 113253Article in journal (Refereed) Published
Abstract [en]

To understand the reasons behind the large environmental impact from buildings the whole life cycle needs to be considered. Therefore, this study evaluates the carbon dioxide emissions in all stages of a single-family house in Sweden from the production of building materials, followed by construction and user stages until the end-of-life of the building in a life cycle assessment (LCA). The methodology applied is attributional life cycle assessment (LCA) based on ‘One Click LCA’ tool and a calculated life span of 100 years. Global warming potential (GWP) and primary energy (PE) are calculated by using specific data from the case study, furthermore the data regarding building materials are based on Environmental Product Declarations (EPDs). The results show that the selection of wood-based materials has a significantly lower impact on the carbon dioxide emissions in comparison with non-wood based materials. The total emissions for this single-family house in Sweden are 6 kg CO 2 e/m 2 /year. The production stage of building materials, including building systems and installations represent 30% of the total carbon dioxide equivalent emissions, while the maintenance and replacement part represents 37%. However, energy use during the in-use stage of the house recorded lower environmental impact (21%) due to the Swedish electricity mix that is mostly based on energy sources with low carbon dioxide emissions. The water consumption, construction and the end-of-life stages have shown minor contribution to the buildings total greenhouse gas (GHG) emissions (12%). The primary energy indicator shows the largest share in the operational phase of the house.

Keywords
Carbon dioxide equivalent emission, Environmental product declaration, Global warming potential, Life cycle assessment, Primary energy, Single-family house
National Category
Energy Systems
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-30118 (URN)10.1016/j.apenergy.2019.05.056 (DOI)2-s2.0-85065788114 (Scopus ID)
Available from: 2019-05-31 Created: 2019-05-31 Last updated: 2019-06-03Bibliographically approved
diva2:1306048
Open this publication in new window or tab >>Life cycle assessment of building materials for a single-family house in Sweden
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2019 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 158, p. 3547-3552Article in journal (Refereed) Published
Abstract [en]

The Nordic countries have shown great interest in using Life Cycle Assessment (LCA) in the building sector compared to the past years. Sweden has set up an objective to be carbon neutral (no greenhouse gas emissions to the atmosphere) by 2045. This paper presents a case study of a single-family house “Dalarnas Villa” in the region Dalarna, Sweden within a 100-year perspective. The assessment is implemented using a new software based on hard data agreed by Environmental Product Declarations (EPDs). It focuses on building materials, transport distances of the materials, and replacement of essential construction materials. The LCA in this study demonstrates the environmental impact related to building materials from production and construction phase including transport, replacement and deconstruction phase. The study does not cover energy use and water consumption. The results show that the building slab made by concrete is the part of the construction most contributing to CO2e, while the wood frame and cellulose insulation have low environmental impact. Replacement of materials takes nearly half of total environmental impact over 100 years. Having a large share of wood-based products, make greenhouse gas emissions remains low.

Keywords
carbon dioxide equivalent (CO2e; global warming potential (GWP); life cycle assessment (LCA); One Click LCA
National Category
Civil Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-29913 (URN)10.1016/j.egypro.2019.01.913 (DOI)000471031703144 ()2-s2.0-85063874633 (Scopus ID)
Conference
10th International Conference on Applied Energy (ICAE2018), 22-25 August 2018, Hong Kong, China
Available from: 2019-04-23 Created: 2019-04-23 Last updated: 2019-07-04Bibliographically approved
Swing Gustafsson, M., Myhren, J. A., Dotzauer, E. & Gustafsson, M. (2019). Life cycle cost of building energy renovation measures, considering future energy production scenarios. Energies, 12(14), Article ID 2719.
Open this publication in new window or tab >>Life cycle cost of building energy renovation measures, considering future energy production scenarios
2019 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 12, no 14, article id 2719Article in journal (Refereed) Published
Abstract [en]

A common way of calculating the life cycle cost (LCC) of building renovation measures is to approach it from the building side, where the energy system is considered by calculating the savings in the form of less bought energy. In this study a wider perspective is introduced. The LCC for three different energy renovation measures, mechanical ventilation with heat recovery and two different heat pump systems, are compared to a reference case, a building connected to the district heating system. The energy system supplying the building is assumed to be 100% renewable, where eight different future scenarios are considered. The LCC is calculated as the total cost for the renovation measures and the energy systems. All renovation measures result in a lower district heating demand, at the expense of an increased electricity demand. All renovation measures also result in an increased LCC, compared to the reference building. When aiming for a transformation towards a 100% renewable system in the future, this study shows the importance of having a system perspective, and also taking possible future production scenarios into consideration when evaluating building renovation measures that are carried out today, but will last for several years, in which the energy production system, hopefully, will change.

Place, publisher, year, edition, pages
MDPI, 2019
Keywords
life cycle cost, energy system, district heating, energy renovation measures, heat pump, mechanical ventilation with heat recovery, combined heat and power, wind power
National Category
Civil Engineering
Research subject
Energy and Built Environments
Identifiers
urn:nbn:se:du-30645 (URN)10.3390/en12142719 (DOI)000478999400079 ()
Available from: 2019-08-29 Created: 2019-08-29 Last updated: 2019-08-29Bibliographically approved
Lidberg, T., Gustafsson, M., Myhren, J. A., Olofsson, T. & Ödlund, L. (2018). Environmental impact of energy refurbishment of buildings within different district heating systems. Applied Energy, 227(SI), 231-238
Open this publication in new window or tab >>Environmental impact of energy refurbishment of buildings within different district heating systems
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2018 (English)In: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 227, no SI, p. 231-238Article in journal (Refereed) Published
Abstract [en]

The refurbishment of existing buildings is often considered a way to reduce energy use and CO2 emissions in the building stock. This study analyses the primary energy and CO2 impact of refurbishing a multi-family house with different refurbishment packages, given various district heating systems. Four models of typical district heating systems were defined to represent the Swedish district heating sector. The refurbishment packages were chosen to represent typical, yet innovative ways to improve the energy efficiency and indoor climate of a multi-family house. The study was made from a system perspective, including the valuation of changes in electricity use on the margin. The results show a significant difference in primary energy use for the different refurbishment packages, depending on both the package itself as well as the type of district heating system. While the packages with heat pumps had the lowest final energy use per m2 of floor area, air heat recovery proved to reduce primary energy use and emissions of CO2-equivalents more, independent of the type of district heating system, as it leads to a smaller increase in electricity use.

Keywords
District heating; Primary energy; Energy refurbishment; Building simulation; Multi-family house
National Category
Civil Engineering
Research subject
Energy, Forests and Built Environments
Identifiers
urn:nbn:se:du-25709 (URN)10.1016/j.apenergy.2017.07.022 (DOI)000445987200025 ()2-s2.0-85026287103 (Scopus ID)
Available from: 2017-08-07 Created: 2017-08-07 Last updated: 2018-10-19Bibliographically approved
Swing Gustafsson, M., Myhren, J. A. & Dotzauer, E. (2018). Life cycle cost of heat supply to areas with detached houses: a comparison of district heating and heat pumps from an energy system perspective. Energies, 11(12), Article ID 3266.
Open this publication in new window or tab >>Life cycle cost of heat supply to areas with detached houses: a comparison of district heating and heat pumps from an energy system perspective
2018 (English)In: Energies, ISSN 1996-1073, E-ISSN 1996-1073, Vol. 11, no 12, article id 3266Article in journal (Refereed) Published
Abstract [en]

There are different views on whether district heating (DH) or heat pumps (HPs) is or are the best heating solution in order to reach a 100% renewable energy system. This article investigates the economic perspective, by calculating and comparing the energy system life cycle cost (LCC) for the two solutions in areas with detached houses. The LCC is calculated using Monte Carlo simulation, where all input data is varied according to predefined probability distributions. In addition to the parameter variations, 16 different scenarios are evaluated regarding the main fuel for the DH, the percentage of combined heat and power (CHP), the DH temperature level, and the type of electrical backup power. Although HP is the case with the lowest LCC for most of the scenarios, there are alternatives for each scenario in which either HP or DH has the lowest LCC. In alternative scenarios with additional electricity transmission costs, and a marginal cost perspective regarding the CHP investment, DH has the lowest LCC overall, taking into account all scenarios. The study concludes that the decision based on energy system economy on whether DH should expand into areas with detached houses must take local conditions into consideration.

Place, publisher, year, edition, pages
MDPI, 2018
Keywords
Combined heat and power, District heating, Energy system, Heat pump, Life cycle cost
National Category
Energy Engineering
Research subject
Energy, Forests and Built Environments
Identifiers
urn:nbn:se:du-28927 (URN)10.3390/en11123266 (DOI)000455358300027 ()2-s2.0-85059252156 (Scopus ID)
Available from: 2018-11-26 Created: 2018-11-26 Last updated: 2019-02-01Bibliographically approved
Swing Gustafsson, M., Myhren, J. A. & Dotzauer, E. (2018). Potential for district heating to lower peak electricity demand in a medium-size municipality in Sweden. Journal of Cleaner Production, 186, 1-9
Open this publication in new window or tab >>Potential for district heating to lower peak electricity demand in a medium-size municipality in Sweden
2018 (English)In: Journal of Cleaner Production, ISSN 0959-6526, E-ISSN 1879-1786, Vol. 186, p. 1-9Article in journal (Refereed) Published
Abstract [en]

Sweden faces several challenges with more intermittent power in the energy system. One challenge is to have enough power available in periods with low intermittent production. A solution could be to reduce peak demand and at the same time produce more electricity during these hours. One way of doing this is to convert electricity-based heating in buildings to district heating based on combined heat and power. The study analyzes how much a Swedish municipality can contribute to lowering peak electricity demand. This is done by quantifying the potential to reduce the peak demand for six different scenarios of the future heat demand and heat market shares regarding two different energy carriers: electricity-based heating and district heating. The main finding is that there is a huge potential to decrease peak power demand by the choice of energy carrier for the buildings’ heating system. In order to lower electricity peak demand in the future, the choice of heating system is more important than reducing the heat demand itself. For the scenario with a large share of district heating, it is possible to cover the electricity peak demand in the municipality by using combined heat and power.

Keywords
Combined heat and power, District heating, Electricity peak demand
National Category
Energy Engineering
Research subject
Energy, Forests and Built Environments
Identifiers
urn:nbn:se:du-27621 (URN)10.1016/j.jclepro.2018.03.038 (DOI)000430785600001 ()2-s2.0-85046012248 (Scopus ID)
Available from: 2018-05-07 Created: 2018-05-07 Last updated: 2018-05-15Bibliographically approved
Gu, Y., Zhang, X., Myhren, J. A., Han, M., Chen, X. & Yuan, Y. (2018). Techno-economic analysis of a solar photovoltaic/thermal (PV/T) concentrator for building application in Sweden using Monte Carlo method. Energy Conversion and Management, 165, 8-24
Open this publication in new window or tab >>Techno-economic analysis of a solar photovoltaic/thermal (PV/T) concentrator for building application in Sweden using Monte Carlo method
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2018 (English)In: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 165, p. 8-24Article in journal (Refereed) Published
Abstract [en]

The solar energy share in Sweden will grow up significantly in next a few decades. Such transition offers not only great opportunity but also uncertainties for the emerging solar photovoltaic/thermal (PV/T) technologies. This paper therefore aims to conduct a techno-economic evaluation of a reference solar PV/T concentrator in Sweden for building application. An analytical model is developed based on the combinations of Monte Carlo simulation techniques and multi energy-balance/financial equations, which takes into account of the integrated uncertainties and risks of various variables. In the model, 11 essential input variables, i.e. average daily solar irradiance, electrical/thermal efficiency, prices of electricity/heating, operation & management (OM) cost, PV/T capital cost, debt to equity ratio, interest rate, discount rate, and inflation rate, are considered, while the economic evaluation metrics, such as levelized cost of energy (LCOE), net present value (NPV), and payback period (PP), are primarily assessed. According to the analytical results, the mean values of LCOE, NPV and PP of the reference PV/T connector are observed at 1.27 SEK/kW h (0.127 €/kW h), 18,812.55 SEK (1881.255 €) and 10 years during its 25 years lifespan, given the project size at 10.37 m2 and capital cost at 4482–5378 SEK/m2 (448.2–537.8 €/m2). The positive NPV indicates that the investment on the selected PV/T concentrator will be profitable as the projected earnings exceeds the anticipated costs, depending on the NPV decision rule. The sensitivity analysis and the parametric study illustrate that the economic performance of the reference PV/T concentrator in Sweden is mostly proportional to solar irradiance, debt to equity ratio and heating price, but disproportionate to capital cost and discount rate. Together with additional market analysis of PV/T technologies in Sweden, it is expected that this paper could clarify the economic situation of PV/T technologies in Sweden and provide a useful model for their further investment decisions, in order to achieve sustainable and low-carbon economics, with an expanded quantitative discussion of the real economic or policy scenarios that may lead to those outcomes.

Keywords
PV/T, Monte Carlo, Economic, LCOE, NPV, Payback period
National Category
Energy Systems
Research subject
Energy, Forests and Built Environments
Identifiers
urn:nbn:se:du-27422 (URN)10.1016/j.enconman.2018.03.043 (DOI)000433269200002 ()2-s2.0-85044112630 (Scopus ID)
Available from: 2018-03-21 Created: 2018-03-21 Last updated: 2019-08-26Bibliographically approved
Myhren, J. A., Heier, J., Hugosson, M. & Zhang, X. (2018). The perception of Swedish housing owner’s on the strategies to increase the rate of energy efficient refurbishment of multi-family buildings. Intelligent Buildings International
Open this publication in new window or tab >>The perception of Swedish housing owner’s on the strategies to increase the rate of energy efficient refurbishment of multi-family buildings
2018 (English)In: Intelligent Buildings International, ISSN 1750-8975, E-ISSN 1756-6932Article in journal (Refereed) Epub ahead of print
Abstract [en]

Improving the energy performance of existing buildings is crucial for reaching both EU and national climate and energy targets. The main objective of this study was to map challenges that Swedish housing owners perceive when making energy-efficiency refurbishments. A secondary objective was to compare how well these challenges relate to national strategies. The study applied a combined methods approach with audience response meters and in-depth qualitative semi-structured interviews. The housing owners express the view that they have sufficient knowledge of national ambitions to improve the energy performance of buildings and welcome the new building regulations. Despite this supposed knowledge and the current economic situation with beneficial loans, the refurbishment rate still remains low. The housing owners explain that they are concerned about the ‘performance gap’ and request more accurate energy performance predictions. They are also waiting for proof that all sustainability goals can be reached in reality. Probably, too few projects fulfilling ambitions in all categories: economically, socially and energy-wise have been followed up and demonstrated nationally. The new national information centre on refurbishment of buildings may help to spread information about such projects, raise awareness and thus increase the refurbishment rate.

Keywords
Energy conservation measures, facilities management, stakeholders, sustainable development
National Category
Energy Engineering
Research subject
Energy, Forests and Built Environments, Varsam energieffektiv renovering Tjärna ängar
Identifiers
urn:nbn:se:du-29244 (URN)10.1080/17508975.2018.1539390 (DOI)2-s2.0-85059056313 (Scopus ID)
Available from: 2019-01-03 Created: 2019-01-03 Last updated: 2019-01-07Bibliographically approved
Lidberg, T., Gustafsson, M., Myhren, J. A., Olofsson, T. & Trygg, L. (2017). Comparing different building energy efficiency refurbishment packages performed within different district heating systems. Paper presented at 8th International Conference on Applied Energy, ICAE 2016; Beijing; China. Energy Procedia, 105, 1719-1724
Open this publication in new window or tab >>Comparing different building energy efficiency refurbishment packages performed within different district heating systems
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2017 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 1719-1724Article in journal (Refereed) Published
Abstract [en]

This study analyses the differences in primary energy (PE) use of a multi-family building refurbished with different refurbishment packages situated in different district heating systems (DHS). Four models of typical DHS are defined to represent the Swedish DH sector. The refurbishment packages are chosen to represent typical, yet innovative ways to improve the energy efficiency of a representative multi-family building in Sweden. The study was made from a broad system perspective, including valuation of changes in electricity use on the margin. The results show a significant difference in PE savings for the different refurbishment packages, depending on both the package itself as well as the type of DHS. Also, the package giving the lowest specific energy use per m2 was not the one which saved the most PE. © 2017 The Authors.

Keywords
building simulation, District heating, energy efficient refurbishment, multi-family building, primary energy
National Category
Civil Engineering
Research subject
Energy, Forests and Built Environments
Identifiers
urn:nbn:se:du-25604 (URN)10.1016/j.egypro.2017.03.492 (DOI)2-s2.0-85020745626 (Scopus ID)
Conference
8th International Conference on Applied Energy, ICAE 2016; Beijing; China
Available from: 2017-07-15 Created: 2017-07-15 Last updated: 2018-05-29Bibliographically approved
Swing Gustafsson, M., Myhren, J. A. & Dotzauer, E. (2017). Mapping of heat and electricity consumption in a medium size municipality in Sweden. Paper presented at 8th International Conference on Applied Energy, ICAE2016, 8-11 October 2016, Beijing, China. Energy Procedia, 105, 1434-1439
Open this publication in new window or tab >>Mapping of heat and electricity consumption in a medium size municipality in Sweden
2017 (English)In: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, p. 1434-1439Article in journal (Refereed) Published
Abstract [en]

The Nordic electricity system faces many challenges with an increased share of intermittent power from renewable sources. One such challenge is to have enough capacity installed to cover the peak demands. In Sweden these peaks appear during the winter since a lot of electricity is used for heating. In this paper a mapping of the heat and electricity consumption in a medium size municipality in Sweden is presented. The paper analyze the potential for a larger market share of district heating (DH) and how it can affect the electrical power balance in the case study. The current heat market (HM) and electricity consumption is presented and divided into different user categories. Heating in detached houses not connected to DH covers 25 % of the HM, and 30 % of the electricity consumption during the peak hours. Converting the detached houses not connected to DH in densely populated areas to DH could reduce the annual electricity consumption by 10 %, and the electricity consumption during the peak hours by 20 %.

Keywords
District heating ;heat market ;electrical power balance ;combined heat and power ;detached houses ;electricity consumption
National Category
Energy Engineering
Research subject
Energy, Forests and Built Environments
Identifiers
urn:nbn:se:du-23586 (URN)10.1016/j.egypro.2017.03.534 (DOI)
Conference
8th International Conference on Applied Energy, ICAE2016, 8-11 October 2016, Beijing, China
Funder
Knowledge Foundation
Available from: 2016-12-15 Created: 2016-12-15 Last updated: 2017-06-05Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-9943-9878

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