| 1. |
- Cowie, A. L., et al.
(författare)
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Applying a science-based systems perspective to dispel misconceptions about climate effects of forest bioenergy
- 2021
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Ingår i: Global Change Biology Bioenergy. - : John Wiley and Sons Inc. - 1757-1693 .- 1757-1707. ; 13:8, s. 1210-1231
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Tidskriftsartikel (refereegranskat)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.
(författare)
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Building energy-efficiency standards in a life cycle primary energy perspective
- 2011
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 43:7, s. 1589-1597
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Tidskriftsartikel (refereegranskat)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.
(författare)
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Climate impacts of wood vs. non-wood buildings
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)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.
(författare)
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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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Ingår i: Applied Energy. - : Elsevier BV. - 0306-2619 .- 1872-9118. ; 92:1, s. 462-472
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Tidskriftsartikel (refereegranskat)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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| 5. |
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| 6. |
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| 7. |
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| 8. |
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| 9. |
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| 10. |
- Dodoo, Ambrose, 1979-, et al.
(författare)
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Lifecycle carbon implications of conventional and low-energy multi-storey timber building systems
- 2014
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Ingår i: Energy and Buildings. - : Elsevier. - 0378-7788 .- 1872-6178. ; 82, s. 194-210
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Tidskriftsartikel (refereegranskat)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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| 11. |
- Dodoo, Ambrose, 1979-, et al.
(författare)
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Lifecycle primary energy analysis of low-energy timber building systems for multi-story residential buildings
- 2014
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 81, s. 84-97
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Tidskriftsartikel (refereegranskat)abstract
- A system-wide lifecycle approach is used here to explore the primary energy implications of three timber building systems for a multi-storey building designed to a high energy-efficiency level. The three building systems are: cross laminated timber, beam -and-column, and modular prefabricated systems. The analysis considers the energy and material flows in the production, use and post-use lifecycle stages of the buildings. The effects of insulation material options and the contribution of different building elements to the production energy for the buildings are explored. The results show that external and internal walls account for the biggest share of the production energy for all building systems and its contribution is comparable for the different systems. In contrast, there is significant variation in the production primary energy for the roof-ceilings and intermediate floor-ceilings for the different building systems. Overall, the cross laminated timber building system gives the lowest lifecycle primary energy balance, as this building is insulated with stone wool and has better airtightness in contrast to the other building systems which are insulated with glass wool and have lower airtightness performance. With improved airtightness and insulation substitution, the total primary energy use for the beam-and-column and modular building systems can be reduced by 7% and 9%, respectively.
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| 12. |
- Dodoo, Ambrose, 1979-, et al.
(författare)
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Lumber recycling
- 2024. - 2
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Ingår i: Handbook of Recycling State-of-the-art for Practitioners, Analysts, and Scientists. - : Elsevier. - 9780323855143 - 9780323860130 ; , s. 463-479
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Bokkapitel (refereegranskat)abstract
- This chapter discusses recent trends in management of postuse wood products and gives an overview of benefits and constraints associated with effective end-of-life management of wood. It highlights the implications of postuse wood management from resource efficiency and climate perspectives. Primary energy and GHG balances are important metrics to understand the resource efficiency of climate change mitigation strategies involving postuse wood products. The chapter describes mechanisms through which postuse management of recovered wood materials can affect primary energy use and GHG impacts of wood products. To further understand the implications of different postuse management options for wood products, we then explore several quantitative scenarios. There is potential for efficient management of postuse wood products by directing these resources to cascade uses including reuse, recycling, and energy recovery. This can offer significant opportunities to improve resource efficiency and reduce greenhouse gas emissions in the built environment.
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| 13. |
- Dodoo, Ambrose, 1979-, et al.
(författare)
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Modeling Carbon Footprint of Wood-Based Products and Buildings
- 2015
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Ingår i: The Carbon Footprint Handbook. - London : CRC Press. - 9781482262223 - 9780429160493 ; , s. 143-162
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Bokkapitel (refereegranskat)abstract
- Efforts to reduce greenhouse gas (GHG) emissions and thereby mitigate global climate change are receiving increasing attention in many countries today. There is growing recognition that the current trends in energy supply and demand are not consistent with the goals of sustainable development. Of the global primary energy supply of 549 EJ in 2011, fossil fuels constituted 82%, and biofuels, nuclear, and hydro accounted for about 10, 5, and 2%, respectively (IEA 2013a). Fossil-fuel combustion is the major anthropogenic source of GHG emissions (IPCC 2013). A less significant share of anthropogenic CO2 emission is also connected to non-energy related activities including land-use practices and industrial process reactions. Fossil-fuel combustion and industrial process reactions accounted for 78% of the global total GHG emission increase between 1970 and 2010 (IPCC 2014). Figure 7.1 shows a breakdown of the global total primary energy supply (TPES) and associated CO2 emission by fuel type in 2011 (IEA 2013b). Major studies suggest that fossil fuels are very likely to account for a significant share of future primary energy use, even if effective measures are implemented to promote resource efficiency and sustainable energy systems in the global community (IPCC 2000a,b; IEA 2011). There is growing interest in strategies to reduce fossil-fuel use, thereby creating a resource-efficient built environment with low-carbon footprint.
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| 14. |
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| 15. |
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| 16. |
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| 17. |
- Dodoo, Ambrose, 1979-, et al.
(författare)
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Primary energy implications of ventilation heat recovery in residential buildings
- 2011
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Ingår i: Energy and Buildings. - : Elsevier BV. - 0378-7788 .- 1872-6178. ; 43:7, s. 1566-1572
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we analyze the impact of ventilation heat recovery (VHR) on the operation primary energy use in residential buildings. We calculate the operation primary energy use of a case-study apartment building built to conventional and passive house standard, both with and without VHR, and using different end-use heating systems including electric resistance heating, bedrock heat pump and district heating based on combined heat and power (CHP) production. VHR increases the electrical energy used for ventilation and reduces the heat energy used for space heating. Significantly greater primary energy savings is achieved when VHR is used in resistance heated buildings than in district heated buildings. For district heated buildings the primary energy savings are small. VHR systems can give substantial final energy reduction, but the primary energy benefit depends strongly on the type of heat supply system, and also on the amount of electricity used for VHR and the airtightness of buildings. This study shows the importance of considering the interactions between heat supply systems and VHR systems to reduce primary energy use in buildings.
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| 18. |
- Dodoo, Ambrose, 1979-, et al.
(författare)
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Recycling of lumber
- 2014. - 1
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Ingår i: Handbook of recycling. - Waltham, MA : Elsevier. - 9780123964595 ; , s. 151-163
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Bokkapitel (refereegranskat)abstract
- Wood from sustainably managed forests can play important roles both as material and as fuel in a transition to a low-carbon society. Wood is widely used as an energy source and as a physical and structural material in diverse applications, including furniture and joinery, pulp and paper, and construction material. There is large potential to improve resource efficiency and thereby reduce greenhouse gas (GHG) emissions through efficient management of post-use wood materials. This chapter explores post-use management of wood products from resource efficiency and climate perspectives. Primary energy and GHG balances are important metrics to understand the resource efficiency of climate change mitigation strategies involving post-use wood products. Primary energy use largely determines natural resource efficiency and steers the environmental impacts of material recovery and production. This chapter describes the mechanisms through which post-use management of recovered wood materials can affect primary energy use and GHG impacts of wood products. To further understand the implications of different post-use management options for wood products, we then explore several quantitative case-studies.
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| 19. |
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| 20. |
- Eriksson, Ola, et al.
(författare)
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Climate change mitigation through increased wood use in the European construction sector - towards an integrated modelling framework
- 2012
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Ingår i: European Journal of Forest Research. - : Springer. - 1612-4669 .- 1612-4677. ; 131:1, s. 131-144
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Tidskriftsartikel (refereegranskat)abstract
- Using wood as a building material affects the carbon balance through several mechanisms. This paper describes a modelling approach that integrates a wood product substitution model, a global partial equilibrium model, a regional forest model and a stand-level model. Three different scenarios were compared with a business-as-usual scenario over a 23-year period (2008-2030). Two scenarios assumed an additional one million apartment flats per year will be built of wood instead of non-wood materials by 2030. These scenarios had little effect on markets and forest management and reduced annual carbon emissions by 0.2-0.5% of the total 1990 European GHG emissions. However, the scenarios are associated with high specific CO2 emission reductions per unit of wood used. The third scenario, an extreme assumption that all European countries will consume 1-m3 sawn wood per capita by 2030, had large effects on carbon emission, volumes and trade flows. The price changes of this scenario, however, also affected forest management in ways that greatly deviated from the partial equilibrium model projections. Our results suggest that increased wood construction will have a minor impact on forest management and forest carbon stocks. To analyse larger perturbations on the demand side, a market equilibrium model seems crucial. However, for that analytical system to work properly, the market and forest regional models must be better synchronized than here, in particular regarding assumptions on timber supply behaviour. Also, bioenergy as a commodity in market and forest models needs to be considered to study new market developments; those modules are currently missing
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| 21. |
- Gustavsson, Leif, 1954-, et al.
(författare)
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Climate change effects of forestry and substitution of carbon-intensive materials and fossil fuels
- 2017
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 67:January, s. 612-624
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Tidskriftsartikel (refereegranskat)abstract
- We estimate the climate effects of directing forest management in Sweden towards increased carbon storage in forests with more land set-aside for protection, or towards increased forest production for the substitution of carbon-intensive materials and fossil fuels, relative to a reference case of current forest management. We develop various scenarios of forest management and biomass use to estimate the carbon balances of the forest systems, including ecological and technological components, and their impacts on the climate in terms of radiative forcing. The scenario with increased set-aside area and the current level of forest residue harvest resulted in lower cumulative carbon emissions compared to the reference case for the first 90 years, but then showed higher emissions as reduced forest harvest led to higher carbon emissions from energy and material systems. For the reference case of current forest management, increased harvest of forest residues gave increased climate benefits. The most climatically beneficial alternative, expressed as reduced cumulative radiative forcing, in both the short and long terms is a strategy aimed at high forest production, high residue recovery rate, and high efficiency utilization of harvested biomass. Active forest management with high harvest levels and efficient forest product utilization will provide more climate benefit, compared to reducing harvest and storing more carbon in the forest.
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| 22. |
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| 23. |
- Gustavsson, Leif, 1954-, et al.
(författare)
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Climate effects of forestry and substitution of concrete buildings and fossil energy
- 2021
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 136, s. 1-15
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Tidskriftsartikel (refereegranskat)abstract
- Forests can help mitigate climate change in different ways, such as by storing carbon in forest ecosystems, and by producing a renewable supply of material and energy products. We analyse the climate implications of different scenarios for forestry, bioenergy and wood construction. We consider three main forestry scenarios for Kronoberg County in Sweden, over a 201-year period. The Business-as-usual scenario mirrors today’s forestry while in the Production scenario the forest productivity is increased by 40% through more intensive forestry. In the Set-aside scenario 50% of forest land is set-aside for conservation. The Production scenario results in less net carbondioxide emissions and cumulative radiative forcing compared to the other scenarios, after an initial period of 30–35 years during which the Set-aside scenario has less emissions. In the end of the analysed period, the Production scenario yields strong emission reductions, about ten times greater than the initial reduction in the Set-aside scenario. Also, the Set-aside scenario has higher emissions than Business-as-usual after about 80 years. Increasing the harvest level of slash and stumps results in climate benefits, due to replacement of more fossil fuel. Greatest emission reduction is achieved when biomass replaces coal, and when modular timber buildings are used. In the long run, active forestry with high harvest and efficient utilisation of biomass for replacement of carbon-intensive non-wood products and fuels provides significant climate mitigation, in contrast to setting aside forest land to store more carbon in the forest and reduce the harvest of biomass.
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| 24. |
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| 25. |
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| 26. |
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| 27. |
- Sathre, Roger, 1964-, et al.
(författare)
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A lifecycle comparison of natural resource use and climate impact of biofuel and electric cars
- 2021
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 237
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Tidskriftsartikel (refereegranskat)abstract
- Here we compare the biomass feedstock use, primary energy use, net CO2 emission, and cumulative radiative forcing of passenger cars powered by different energy pathways. We consider the full lifecycle of the vehicles, including manufacture and operation. We analyze battery electric vehicles (BEVs) powered by standalone electricity generation using woody biomass, with and without CCS, and with integration of wind electricity. We analyze internal combustion vehicles (ICVs) powered by fossil gasoline and by biomethanol derived from woody biomass, with and without carbon capture and sequestration (CCS). Our system boundaries include all fossil and biogenic emissions from technical systems, and the avoided decay emissions from harvest residue left in the forest. We find that the pathways using electricity to power BEVs have strongly lower climate impacts, compared to the liquid-fueled ICV pathways using biomethanol and gasoline. The pathways using bioelectricity with CCS result in negative emissions leading to global cooling. The pathways using gasoline and biomethanol have substantial climate impact, even with CCS. Regardless of energy pathway, smaller cars have consistently lower climate impact than larger cars. These findings suggest that accelerating the current trend toward vehicle electrification, together with scaling up renewable electricity generation, is a wise strategy for climate-adapted passenger car transport. (C) 2021 The Author(s). Published by Elsevier Ltd.
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| 28. |
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| 29. |
- Sathre, Roger, 1964-
(författare)
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Life-Cycle Energy and Carbon Implications of Wood-Based Products and Construction
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Forests can be an important element of an overall strategy to limit the atmospheric concentration of carbon dioxide (CO2) that contributes to climate change. As an integral part of the global carbon cycle, forests remove CO2 from the atmosphere as they grow, and accumulate carbon in tree biomass. Using wood products made from sustainably managed forests can reduce net CO2 emission by substituting in place of fossil fuels and energy-intensive materials. In this thesis the mechanisms by which wood product substitution can affect energy and carbon balances are studied. These include: the energy needed to manufacture wood products compared with alternative materials; the avoidance of industrial process carbon emission from e.g. cement manufacture; the use of wood by-products as biofuel to replace fossil fuels; and the physical storage of carbon in forests and wood materials. A methodological framework is first developed by integrating knowledge from the fields of forestry, industry, construction, and energy. A life cycle perspective is employed encompassing the entire product chain from natural resource acquisition to material disposal or reuse. Analytical challenges that are addressed include the functional unit of comparison, the fossil reference system, land use issues of wood vs. non-wood materials, and the diverse phases of the product life cycle. The methodology is then applied to two multi-storey wood-framed buildings in Sweden and Finland, compared with two functionally equivalent buildings with reinforced concrete structural frames. The results show that less primary energy is needed to produce the wood-framed buildings than the concrete-frame buildings. CO2 emission is significantly lower for the wood-frame buildings, due to reductions in both fossil fuel use and cement calcination process emission. The most important single factor affecting the energy and carbon balances is the use of biomass by-products from the wood product chain as biofuel to replace fossil fuels. Over the life cycle of the wood-framed buildings, the energy of biomass residues from forest operations, wood processing, construction and demolition is greater than the energy inputs to produce the materials in the buildings. Realisation of this benefit is facilitated by integrating and optimising the biomass and energy flows within the forestry, industrial, construction, energy, and waste management sectors. Different forest management regimes are studied in an integrated carbon analysis to quantify the carbon flows and stocks associated with tree biomass, soils, and forest products. Intensified forest management that produces greater quantities of biomass leads to net CO2 emission benefits by augmenting the potential to substitute for fossil fuels and non-wood materials. The increased energy use and carbon emission required for the more intensive forest management, as well as the slight reduction in soil carbon accumulation due to greater removal of forest residues, are more than compensated for by the emission reduction due to product substitution. Carbon stock changes in forests and wood materials can be temporarily significant, but over the building life cycle and forest rotation period the stock change becomes insignificant. In the long term, the active and sustainable management of forests, including their use as a source for wood products and biofuels, allows the greatest potential for reducing net CO2 emission. Implementation issues related to the wider use of wood-based materials to reduce energy use and carbon emission are also explored. An analysis of the effects of energy and taxation costs on the economic competitiveness of materials shows that the cost of energy for material processing, as a percentage of the total cost of finished material, is lower for wood products than for other common non-wood building materials. Energy and carbon taxation affects the cost of wood products less than other materials. The economic benefit of using biomass residues to substitute for fossil fuels also increases as tax rates increase. In general, higher taxation of fossil fuels and carbon emission increases the economic competitiveness of wood construction. An analysis of added value in forest product industries shows that greater economic value is added in the production of structural building materials than in other uses of forest biomass. Co-production of multiple wood-based products increases the total value that is added to the biomass produced on an area of forest land. The results show that production of wood-based building material is favoured economically by climate change mitigation policies, and creates high added value within forest product industries.
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| 30. |
- Sathre, Roger, 1964-, et al.
(författare)
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Lifecycle climate impact and primary energy use of electric and biofuel cargo trucks
- 2023
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Ingår i: Global Change Biology Bioenergy. - : John Wiley & Sons. - 1757-1693 .- 1757-1707. ; 15:4, s. 508-531
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Tidskriftsartikel (refereegranskat)abstract
- Heavy trucks contribute significantly to climate change, and in 2020 were responsible for 7% of total Swedish GHG emissions and 5% of total global CO2 emissions. Here we study the full lifecycle of cargo trucks powered by different energy pathways, comparing their biomass feedstock use, primary energy use, net biogenic and fossil CO2 emission and cumulative radiative forcing. We analyse battery electric trucks with bioelectricity from stand-alone or combined heat and power (CHP) plants, and pathways where bioelectricity is integrated with wind and solar electricity. We analyse trucks operated on fossil diesel fuel and on dimethyl ether (DME). All energy pathways are analysed with and without carbon capture and storage (CCS). Bioelectricity and DME are produced from forest harvest residues. Forest biomass is a limited resource, so in a scenario analysis we allocate a fixed amount of biomass to power Swedish truck transport. Battery lifespan and chemistry, the technology level of energy supply, and the biomass source and transport distance are all varied to understand how sensitive the results are to these parameters. We find that pathways using electricity to power battery electric trucks have much lower climate impacts and primary energy use, compared to diesel- and DME-based pathways. The pathways using bioelectricity with CCS result in negative emissions leading to global cooling of the earth. The pathways using diesel and DME have significant and very similar climate impact, even with CCS. The robust results show that truck electrification and increased renewable electricity production is a much better strategy to reduce the climate impact of cargo transport than the adoption of DME trucks, and much more primary energy efficient. This climate impact analysis includes all fossil and net biogenic CO2 emissions as well as the timing of these emissions. Considering only fossil emissions is incomplete and could be misleading.
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| 31. |
- Sathre, Roger, 1964-
(författare)
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Technologies to enhance sustainable groundwater use
- 2021
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Ingår i: Global Groundwater. - : Elsevier. - 9780128181720 ; , s. 519-529
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Bokkapitel (refereegranskat)abstract
- The absolute demand for water is increasing due to demographic, industrial, and agricultural growth. Meanwhile, local water resources are constrained based on climate and geology. The deployment of select technologies holds promise to enhance the sustainable use of groundwater resources. Groundwater mapping is an essential first step, to understand the subsurface landscape. This knowledge can then be practically applied to manage and increase groundwater recharge, and to reduce saline groundwater intrusion into freshwater aquifers. Improving water-use efficiency in the agriculture, household, and industrial sectors can increase utility from each available unit of groundwater. However, the net groundwater implications of irrigation efficiency improvements are complex, as “wasted” irrigation water often contributes to groundwater recharge. Technologies can be used to improve the quality of groundwater contaminated by salt, arsenic, fluoride, and organic pathogens. Finally, in regions suffering from economic water scarcity, improved technologies for creating wells and pumping groundwater can increase access to groundwater.
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| 32. |
- Sathre, Roger, 1964-, et al.
(författare)
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Water Security in South Asian Cities : A Review of Challenges and Opportunities
- 2022
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Ingår i: CivilEng. - : MDPI. - 2673-4109. ; 3:4, s. 873-894
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Tidskriftsartikel (refereegranskat)abstract
- Achieving water security in South Asian cities will require a realistic and holistic understanding of the challenges that are growing in extent and severity. These challenges include the rapid rise in urban household water demand due to both overall population growth and increasing urbanization rate. Additionally, surface water supply in closed river basins is fully utilized, and there is little opportunity in these regions to increase the extraction of surface water to meet rising demands. Furthermore, groundwater extraction in most regions exceeds natural recharge rates, leading to rapidly falling annual water tables and seasonal depletion in hard rock regions and to gradually declining water tables requiring deeper wells and increased pumping effort in alluvial regions. Additionally, even in cities with abundant water resources, poorer segments of the population often face economic water scarcity and lack the means to access it. Nevertheless, there are important potential engineering opportunities for achieving water security in South Asian cities. Much withdrawn water is lost due to urban water distribution inefficiency, and a range of proven techniques exist to improve distribution. Metering of urban water can lead to structural improvements of management and billing, though the water needs of the poorest city residents must be ensured. Industrial water-use efficiency can be significantly improved in manufacturing and electricity generation. The quantities of wastewater generated in South Asia are large, thus treating and reusing this water for other purposes is a strong lever in enhancing local water security. There is limited potential for rooftop rainwater harvesting and storage, though capture-enhanced groundwater recharge can be important in some areas. Some individual inter-basin transfer projects may prove worthwhile, but very-large-scale projects are unlikely to contribute practically to urban water security. Overall, the water challenges facing South Asian cities are complex, and although no single intervention can definitively solve growing problems, numerous actions can be taken on many fronts to improve water security.
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| 33. |
- Wright, Caleb, et al.
(författare)
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The global challenge of clean cooking systems
- 2020
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Ingår i: Food Security. - : Springer. - 1876-4517 .- 1876-4525. ; 12:6, s. 1219-1240
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Tidskriftsartikel (refereegranskat)abstract
- Cooking is an essential and energy-intensive activity. Populations in industrialized countries enjoy nearly universal access to electricity and gas for clean cooking, while about 2.5 billion people in low- and middle-income countries use solid fuels such as wood, charcoal, coal, crop residue and dung for their daily cooking. These traditional solid fuel cooking systems negatively affect the health and reduce the opportunities of cookstove users, who are disproportionately women and children. Solid fuel cooking also presents a number of detrimental environmental impacts, such as ambient air pollution and forest degradation in some regions. Access to cleaner cooking fuels such as gas and electricity is expanding, but is constrained by the higher costs and logistical challenges of such systems. This review investigates the technologies and systems that are currently used to cook food, with a focus on low-income populations. It identifies key challenges that hinder a global transition to clean and sustainable cooking. Finally, it reflects on the recent success of Liquified Petroleum Gas (LPG) along with other fossil fuel-based cooking systems, and discusses a potential transition to renewable energy-based cooking.
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