| 1. |
- Gustavsson, Leif, et al.
(författare)
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Energy conservation and conversion of electrical heating systems in detached houses
- 2007
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 39:6, s. 717-726
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Tidskriftsartikel (refereegranskat)abstract
- In this study, a Swedish house built in 1974, heated with resistance heaters was analysed. Different options for changing the heating system and electricity production were compared for this type of detached house, assuming coal-based electricity production as a reference. Changes in the fuel used, the electricity production technology, the end-use heating technology and the heat demand were analysed. The aim was to show how these different parts of the energy system interact and to evaluate the cost-effectiveness of reducing CO2 emission and primary energy use by different combinations of changes. The results showed that the CO2 emission and primary energy use could be reduced by 95 and 70%, respectively, without increased heating costs in a national economic perspective. The choice of end-use heating system had a greater influence than the energy conservation measures on the parameters studied. The energy conservation measures were less cost-effective in combination with the more energy-efficient heating systems, although the fact that they reduced the heat demand, and thus also the investment cost of the new heating system, was taken into account.
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| 2. |
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| 3. |
- Joelsson, Anna, et al.
(författare)
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A life cycle energy perspective on the passive house concept
- 2008
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Ingår i: First International Conference on Building Energy and Environment, Proceedings Vols 1-3. - Dalian, China : Dalian University Technology Press. - 9780981688169 ; , s. 549-556
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Konferensbidrag (refereegranskat)abstract
- When low-energy houses are being built the focus is often to minimize the final (purchased) energy in the operation phase. However, the primary energy is more relevant when evaluating buildings from an environmental perspective. As the. energy for operation decreases, the relative importance of the other life cycle phases increases and influences an optimization aiming at minimizing the life-cycle energy use. We have studied the primary energy use for production and operation of four types of buildings, when using different types of energy supply systems for the heating. We show that a house from the 1970s after refurbishment and change of heating supply system had about the same primary energy use as a so-called passive house. The CO2 emissions were 64% lower, when a biomass-based heating system was used. We also illustrate the higher relative importance of the production phase for a building with low energy demand and efficient heat supply systems for operation.
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| 4. |
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| 5. |
- Joelsson, Anna, et al.
(författare)
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District heating and energy efficiency in detached houses of differing size and construction
- 2009
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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 86:2, s. 126-134
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 6. |
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| 7. |
- Joelsson, Anna, et al.
(författare)
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Implementation of Energy efficiency in residential areas - public policies versus energy suppliers
- 2008
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Ingår i: First International Conference on Building Energy and Environment, Proceedings Vols 1-3. - Dalian, China : Dalian University Technology Press. - 9780981688169 ; , s. 2070-2077
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Konferensbidrag (refereegranskat)abstract
- In order to realise the potential for energy efficiency in residential areas it requires influencing the many individual house owners that make the decisions. We compare how Swedish energy policy and Swedish energy suppliers influence the house owners in taking decisions about heating systems and house envelope measures. An economic analysis shows how energy policy and electricity cost affects the house owners' economic situation. The house owners' perception is analysed through comprehensive questionnaires, sent out both before and after the implementation of a heating system conversion subsidy and a district heating marketing campaign by an energy supplier. We conclude that a heating system conversion subsidy and electricity tax give relevant incentives to act according to the national policy. We show that the effect on the annual cost of most of the studied policy measures was smaller than the price variations between different energy suppliers. The energy supplier can largely influence both the economic situation and the perceptions of the customers.
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| 8. |
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| 9. |
- Joelsson, Anna, et al.
(författare)
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Multi-storey Wood Buildings in a Life Cycle Primary Energy Perspective
- 2008
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Ingår i: First International Conference on Building Energy and Environment, Proceedints Vols 1-3. - 9780981688169 ; , s. 255-262
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Konferensbidrag (refereegranskat)abstract
- For houses with low operational energy demand, the relative importance of the other life cycle phases is larger than in standard buildings. For such buildings the choice of material becomes more important. Studies have shown that buildings constructed with wood require less energy during the lifecycle, compared to other materials. We have compared the primary energy use for production and operation of a wood building and a concrete building, traditionally constructed, and a low-energy concrete building. We also evaluate the effects of energy efficiency measures applied to the wood building and of different energy supply systems. We show the importance of both material choice and energy supply systems when optimizing life-cycle energy use of buildings.
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| 10. |
- Joelsson, Anna, et al.
(författare)
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Perspectives on implementing energy efficiency in existing Swedish detached houses
- 2008
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Ingår i: Energy Policy. - : Elsevier BV. - 0301-4215 .- 1873-6777. ; 36:1, s. 84-96
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we first analyse energy-efficiency measures in existing electrically heated houses in Sweden from a societal economic perspective. Measures to a house envelopes and to energy supply chains are evaluated through a system analysis approach and we include the external costs of climate change and the effect of different Swedish climatic zones. We find that in a typical house from the 1970s, conversion from electric heating is highly motivated since the mitigation cost of conversion is lower than the estimated external costs of emitted CO2. Both conversions and house envelope measures are more motivated in the northern part of the country, where there is a higher heat demand. A successful implementation of changes requires them to be attractive for consumers to adopt. We therefore secondly analyse the economic conditions for Swedish house owners to implement societal economic cost-efficient measures. We include the economic influence of an investment subsidy for heating system conversion, an income tax deduction for changing windows, customer electricity tax, real estate tax and of the cost of purchased energy from different energy suppliers. Apart from the economics, several other factors affect a house owner's decision to change heating systems. We therefore thirdly analyse house owners' perceptions of different heating supply alternatives based on the results of two comprehensive questionnaires. These different perspectives are combined in a discussion whether the studied policy instruments encourage house owners to implement changes in accordance with the energy-efficiency goals of decision makers. We find that the investment subsidy could be useful to break the lock-in effect of resistance heaters, which house owners seemed to experience. The electricity tax makes heating systems in line with national goals more competitive and efficiency measures to the house envelope more profitable. The reduction of the electricity tax in the northern part of the country has the opposite effect. Also, the increase in real estate tax when implementing energy-efficiency measures gives a contradictory message. The price differences between energy suppliers has a larger impact on the house owners' economic conditions than both subsidies and tax rate changes, and possibly also affect the house owner's attitudes towards various systems.
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