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- Cowie, A. L., et al.
(author)
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Applying a science-based systems perspective to dispel misconceptions about climate effects of forest bioenergy
- 2021
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In: Global Change Biology Bioenergy. - : John Wiley and Sons Inc. - 1757-1693 .- 1757-1707. ; 13:8, s. 1210-1231
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Journal article (peer-reviewed)abstract
- The scientific literature contains contrasting findings about the climate effects of forest bioenergy, partly due to the wide diversity of bioenergy systems and associated contexts, but also due to differences in assessment methods. The climate effects of bioenergy must be accurately assessed to inform policy-making, but the complexity of bioenergy systems and associated land, industry and energy systems raises challenges for assessment. We examine misconceptions about climate effects of forest bioenergy and discuss important considerations in assessing these effects and devising measures to incentivize sustainable bioenergy as a component of climate policy. The temporal and spatial system boundary and the reference (counterfactual) scenarios are key methodology choices that strongly influence results. Focussing on carbon balances of individual forest stands and comparing emissions at the point of combustion neglect system-level interactions that influence the climate effects of forest bioenergy. We highlight the need for a systems approach, in assessing options and developing policy for forest bioenergy that: (1) considers the whole life cycle of bioenergy systems, including effects of the associated forest management and harvesting on landscape carbon balances; (2) identifies how forest bioenergy can best be deployed to support energy system transformation required to achieve climate goals; and (3) incentivizes those forest bioenergy systems that augment the mitigation value of the forest sector as a whole. Emphasis on short-term emissions reduction targets can lead to decisions that make medium- to long-term climate goals more difficult to achieve. The most important climate change mitigation measure is the transformation of energy, industry and transport systems so that fossil carbon remains underground. Narrow perspectives obscure the significant role that bioenergy can play by displacing fossil fuels now, and supporting energy system transition. Greater transparency and consistency is needed in greenhouse gas reporting and accounting related to bioenergy.
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| 2. |
- Dodoo, Ambrose, 1979-, et al.
(author)
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Building energy-efficiency standards in a life cycle primary energy perspective
- 2011
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In: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 43:7, s. 1589-1597
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Journal article (peer-reviewed)abstract
- In this study we analyze the life cycle primary energy use of a wood-frame apartment building designed to meet the current Swedish building code, the Swedish building code of 1994 or the passive house standard, and heated with district heat or electric resistance heating. The analysis includes the primary energy use during the production, operation and end-of-life phases. We find that an electric heated building built to the current building code has greater life cycle primary energy use relative to a district heated building, although the standard for electric heating is more stringent. Also, the primary energy use for an electric heated building constructed to meet the passive house standard is substantially higher than for a district heated building built to the Swedish building code of 1994. The primary energy for material production constitutes 5% of the primary energy for production and space heating and ventilation of an electric heated building built to meet the 1994 code. The share of production energy increases as the energy-efficiency standard of the building improves and when efficient energy supply is used, and reaches 30% for a district heated passive house. This study shows the significance of a life cycle primary energy perspective and the choice of heating system in reducing energy use in the built environment.
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| 3. |
- Dodoo, Ambrose, 1979-, et al.
(author)
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Climate impacts of wood vs. non-wood buildings
- 2016
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Reports (other academic/artistic)abstract
- This report documents the findings of a project commissioned by the SwedishAssociation of Local Authorities and Regions on energy and climateimplications of building structural-frame materials from a life cycle perspective.The report is compiled by researchers within the Sustainable Built EnvironmentGroup (SBER) at Linnaeus University, Växjö, Sweden, and it addresses theterms of reference of the project agreement, including review of existingliterature and reports on energy and climate implications of wood-frame andnon-wood-frame building systems.The report’s primarily focus is: the effect of material choice on different lifecycle stages of a building; the significance of building frame material in relationto the total primary energy use and climate impact of a building; keymethodological issues linked to life cycle analysis of buildings; and theimportance of system perspective in analysis of a building’s climate impacts.
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| 4. |
- Dodoo, Ambrose, 1979-, et al.
(author)
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Effect of thermal mass on life cycle primary energy balances of a concrete- and a wood-frame building
- 2012
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In: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 92:1, s. 462-472
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Journal article (peer-reviewed)abstract
- 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 hourby- 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 benefit of thermal mass inherent in 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 CHP-based district heating would be an effective means of reducing primary energy use in the built environment.
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| 10. |
- Dodoo, Ambrose, 1979-, et al.
(author)
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Lifecycle carbon implications of conventional and low-energy multi-storey timber building systems
- 2014
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In: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 82, s. 194-210
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Journal article (peer-reviewed)abstract
- A consequential-based lifecycle approach is used here to explore the carbon implications of conventional and low-energy versions of three timber multi-storey building systems. The building systems are made of massive wood using cross laminated timber (CLT) elements; beam-and-column using glulam and laminated veneer lumber (LVL) elements; and prefabricated modules using light-frame volume elements. The analysis encompasses the entire resource chains during the lifecycle of the buildings, and tracks the flows of carbon from fossil energy, industrial process reactions, changes in carbon stocks in materials, and potential avoided fossil emissions from substitution of fossil energy by woody residues. The results show that the low-energy version of the CLT building gives the lowest lifecycle carbon emission while the conventional version of the beam-and-column building gives the highest lifecycle emission. Compared to the conventional designs, the low-energy designs reduce the total carbon emissions (excluding from tap water heating and household and facility electricity) by 9%, 8% and 9% for the CLT, beam-and-column and modular systems, respectively, for a 50-year lifespan located in Växjö. The relative significance of the construction materials to the fossil carbon emission varies for the different energy-efficiency levels of the buildings, with insulation dominating for the low-energy houses and plasterboard dominating for the conventional houses.
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