| 1. |
- Dreier, Dennis, 1990-
(författare)
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Transition Technologies for Electrification and Optimisation of Bus Transport Systems
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The topical issue of climate change has increasingly become important as scenarios indicate an increase of 2.5–7.8°C in the global mean temperature by the end of this century, if no greenhouse gas emissions are reduced. The transport sector depends strongly on fossil fuels and has been therefore considered as one key sector concerning climate change mitigation. In this regard, a key role is played by cities, since progressing urbanisation will presumably lead to a higher demand for urban transport.This doctoral thesis addresses the transition phase of public bus transport systems by exploring electrification as a vector for decarbonisation. The C40-city of Curitiba in Southern Brazil is used as a case study. The research is of explorative and empirical nature. Quantitative research methods are applied to compare bus technologies as well as new optimisation models and planning tools are developed to support data analytics and research in the areas of simulation, optimisation and (long-term) planning of energy and transport systems at different levels of consideration.The results from the comparison of different buses show large potentials to save energy and reduce emissions during the operation phase, for example, when using hybrid-electric or plug-in hybrid-electric buses instead of conventional buses. Moreover, energy savings in the operation phase also imply avoidance of fuel production and supply. Additionally, electrified buses can also reduce operational uncertainty caused by varying driving cycles and fluctuating fuel prices concerning an absolute variation of both energy use and fuel cost in the operation phase.A real-time optimisation model was developed, and its concept tested to estimate potentials for energy savings and all-electric operation from the operational optimisation of a plug-in hybrid-electric bus fleet. Different management strategies were simulated concerning the charging schedule and all-electric operation of the bus fleet. While energy savings can be significantly increased through a structural change towards more electrified buses, a large potential to increase the total all-electric operation of the bus fleet was estimated through operational optimisation. Consequently, both a structural change and operational optimisation should be jointly applied to maximise the benefits gained from electrification in a bus transport system.The software system OSeMOSYS-PuLP was developed for empirical deterministic-stochastic modelling based on the OSeMOSYS modelling framework, which enables the use of a Monte Carlo simulation. The open source design of the tool shall enhance transparency and trustworthiness in studies. It is transferable to many cases and makes it possible for analysts and researchers to generate new sets of conclusions together with associated probability distributions considering the use of real-world datasets, e.g. from open data initiatives as the one in Curitiba.In summary, the research findings, applied methods and developed tools can be used to support and inform analysts and decision-makers in the area of transport and energy systems planning in data-driven decision-making processes to develop and assess different technological options and strategies at different levels while considering associated uncertainties.
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| 2. |
- Khan, MD. Ershad Ullah, 1979-
(författare)
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Renewables Based Polygeneration for Rural Development in Bangladesh
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Despite the country's rural electrification programme, kerosene is the predominant source for lighting, and unsustainable and polluting woody biomass is virtually the only option available for cooking. The rural population also struggles with unsafe drinking water in terms of widespread arsenic contamination of well water. The present work has taken an integrated approach in an attempt to mitigate problems through small-scale polygeneration, a concept linking renewable energy sources to these energy needs via novel energy conversion systems.Anaerobic digesters (AD) for biogas production are promising in the rural setting, and field surveys have identified problems in the construction, maintenance and operation of existing AD, particularly in overall performance of household digesters. Based on these results, a number of operational and technological improvements are suggested for employing digesters in polygeneration units. This study also examines one approach for small-scale, low cost arsenic removal in groundwater through air gap membrane distillation, a thermally-driven water purification technology.Integration of biogas production with power generation and water purification is an innovative concept that lies at the core of feasibility analyses conducted in this work. One of the case studies presents a new concept for integrated biogas based polygeneration and analyzes the techno-economic performance of the scheme for meeting the demand of electricity, cooking energy and safe drinking water of 30 households in a rural village of Bangladesh. The specific technologies chosen for the key energy conversion steps are as follows: plug-flow digester; internal combustion engine; and membrane distillation. One major concern is local feedstock availability for the digester, since a single feedstock is impractical to serve both cooking, lighting and water purification systems. In this circumstance solar PV could be a potential option for integrated hybrid systems.
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| 3. |
- Khatiwada, Dilip, 1971-
(författare)
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Assessing the sustainability of bioethanol production in Nepal
- 2010
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Access to modern energy services derived from renewable sources is a prerequisite, not only for economic growth, rural development and sustainable development, but also for energy security and climate change mitigation. The least developed countries (LDCs) primarily use traditional biomass and have little access to commercial energy sources. They are more vulnerable to problems relating to energy security, air pollution, and the need for hard-cash currency to import fossil fuels. This thesis evaluates sugarcane-molasses bioethanol, a renewable energy source with the potential to be used as a transport fuel in Nepal. Sustainability aspects of molasses-based ethanol have been analyzed. Two important indicators for sustainability, viz. net energy and greenhouse gas (GHG) balances have been used to assess the appropriateness of bioethanol in the life cycle assessment (LCA) framework. This thesis has found that the production of bioethanol is energy-efficient in terms of the fossil fuel inputs required to produce it. Life cycle greenhouse gas (GHG) emissions from production and combustion are also lower than those of gasoline. The impacts of important physical and market parameters, such as sugar cane productivity, the use of fertilizers, energy consumption in different processes, and price have been observed in evaluating the sustainability aspects of bioethanol production. The production potential of bioethanol has been assessed. Concerns relating to the fuel vs. food debate, energy security, and air pollution have also been discussed. The thesis concludes that the major sustainability indicators for molasses ethanol in Nepal are in line with the goals of sustainable development. Thus, Nepal could be a good example for other LDCs when favorable governmental policy, institutional set-ups, and developmental cooperation from donor partners are in place to strengthen the development of renewable energy technologies.
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| 4. |
- Johnson, Francis X, 1963-
(författare)
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Exploiting cross-level linkages to steer the bioenergy transition
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis develops the notion of the bioenergy transition as the long-term transformation of biomass from a local resource into a global commodity. An historical assessment is combined with interdisciplinary analysis that focuses especially on liquid biofuels and highlights the environmentally innovative case of bioethanol. The bioenergy transition is investigated from several different perspectives: technical-economic, socio-economic, socio-technical and political-economic. Linkages across different levels from household to global are analysed in relation to the effectiveness of bioenergy policies. In addition to studies at household and national levels, a North-South perspective is taken by including two major regions: the European Union (EU) and the Southern African Development Community (SADC). The relation of EU biofuels policy to international climate and trade regimes is assessed to show how regional-global linkages affect policy design and implementation.Household bioenergy markets in developing countries are poorly articulated and difficult to link to other sectors; a detailed choice model in Ethiopia showed that product-specific factors should be evaluated to inform design of programmes and policies. Municipal and sub-national markets for bioenergy have been successfully linked to national policies to coordinate supply and demand in Brazil and Sweden. Regional market development for biofuels has great potential in southern Africa but regional-national linkages currently remain unexploited. National level efforts remain quite important in terms of energy security and environmental innovation, as evidenced in Brazil, Malawi and Sweden. Biofuels sustainability criteria in the EU Renewable Energy Directive (EU-RED) were evaluated in relation to the international climate and trade regimes and were found to shift some costs onto developing countries. One of the mechanisms for assuring biofuels sustainability is bilateral agreements, which remain untested but potentially effective.Cross-level linkages were often unexploited in the cases studied; national approaches cannot easily capture complementarities across sectors and scales in biophysical and economic terms. Linking biofuels markets across different levels from household to global through regional development policies and specialised governance mechanisms could help to steer the bioenergy transition towards sustainability.
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| 5. |
- Khatiwada, Dilip, 1971-
(författare)
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Assessing the sustainability of bioethanol production in different development contexts: A systems approach
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The continuous depletion of fossil fuel reserves, the global agenda on climate change and threats to energy security have led to increased global interest in the exploration, production and utilisation of bioenergy and biofuels. Access to modern bioenergy carriers derived from the efficient conversion of locally available biomass resources is indispensable for economic growth, rural development and sustainable development in developing countries. Deployment of bioenergy/biofuels technologies has significantly varied across the globe. The least developed countries (LDCs) and developing countries are still highly dependent on traditional biomass technologies with low conversion efficiency, which are typically associated with significant environmental and health impacts. Meanwhile, emerging economies and developed countries are progressively promoting biofuel industries and international trade. They are also engaged in making biofuels a sustainable proposition by developing sustainability criteria. The goal of this thesis is to address the sustainability of bioethanol production derived from one of the key feedstocks/energy crops: sugarcane. This will be done by analysing different development contexts and environmental constraints in terms of geopolitical situation, economic development and state-of-the-art technologies in agro-industrial development. Life cycle assessment (LCA), system studies, and techno-economic optimisation are the main methodological approaches applied in the thesis. The thesis primarily addresses three key questions for analysing the sustainability of bioethanol production.The first research question investigates the key parameters affecting the sustainability of bioethanol production and use in a low-income country using the case of Nepal. The net energy and greenhouse gas (GHG) balances are identified to be the main sustainability criteria of the sugarcane-molasses bioethanol (Paper I and II). Results of the lifecycle studies show that the production of bioethanol is energy-efficient in terms of the fossil fuel inputs required to produce the renewable fuel. Greenhouse gas (GHG) emissions from the production and combustion of ethanol are also lower than those from gasoline. The study also evaluates the socio-economic and environmental benefits of ethanol production and use in Nepal, concluding that the major sustainability indicators are in line with the goals of sustainable development (Paper III). Assessment of the biofuel (molasses-bioethanol) sustainability in Nepal is the first of its kind in low-income countries, and serves also the purpose of motivating the assessment of ethanol production potential in other LDCs, particularly in sub-Saharan Africa.The second question critically evaluates methodologies for accounting the lifecycle GHG emissions of Brazilian sugarcane ethanol in European and American regulations, depicting commonalities and differences among them (Paper IV). GHG emissions are becoming increasingly important as part of sustainability criteria in the context of the expansion of biofuel production and international trade. However, different methodologies still lead to quite different results and interpretation. To make this an operational criterion for international comparisons, it is necessary to establish unified methodological procedures for accounting GHG emissions. The thesis identifies the major issues as N2O emissions from agricultural practices, bioelectricity credits in fuel production, and modelling approaches in estimating emissions related to direct and indirect land use change (LUC & iLUC), that need to be addressed for establishing methodological coherences.The third research question investigates how the sugarcane bioethanol industry can be developed in terms of energy security and the diversification of energy sources. The case of complementarity between bioelectricity and hydropower is evaluated in the cases of Nepal and Brazil and presented in Paper V. Bioelectricity could offer a significant share of electricity supply in both countries provided that favourable political and institutional conditions are applied. Finally, in order to find the choice of technological options for the production of second generation (2G) bioethanol and/or of bioelectricity, a techno-economic optimisation study on the bulk of sugarcane bio-refineries in Brazil is carried out in Paper VI, taking into account the entire lifecycle costs, emissions, and international trade. The study shows that it is worthwhile to upgrade sugarcane bio-refineries. Energy prices, type of power generation systems, biofuel support and carbon tax, and conversion efficiencies are the major factors influencing the technological choice and potential bioethanol trade.In short, this dissertation provides insights on the sustainability of the bioethanol production/industry and its potential role in the mitigation of climate change, improved energy security and sustainable development in different country contexts, as well as methodological contributions for assessing the sustainability of biofuels production in connection with energy and climate policies.
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| 6. |
- Morfeldt, Johannes, 1983-
(författare)
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Tracking Emissions Reductions and Energy Efficiency in the Steel Industry
- 2017
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The iron and steel industry has become increasingly globalised. Market conditions are also changing and de-carbonisation of production is challenging.The objective of this thesis is to assess how energy efficiency and greenhouse gas emissions reductions can be promoted and effectively monitored in the steel industry. The thesis contributes with analyses based on the Malmquist Productivity Index for a top-down analysis of the energy efficiency of EU Member States’ iron and steel production, and Partial Least Squares regression for bottom-up assessments of different monitoring tools. The thesis also contributes with a scrap availability assessment module to enhance the energy system model ETSAP-TIAM.The first phase of the research showed that future production needs to shift towards innovative low-CO2 technologies even when all available recycled material is fully used. Techniques using carbon capture and storage (CCS) as well as hydrogen-based technologies can be expected to become economically viable under tightened climate policies.The second phase of the research showed that current indicators are insufficient. System boundaries of energy use and emissions data do not align with production statistics. Indicators based on energy use or emissions in relation to production in physical terms may be useful to track specific processes. However, current indicators fail to reflect the companies’ product mix. Enhanced energy and climate indicators that adjust for the product mix provide better estimates while failing to reflect the increasing globalisation.Effective monitoring of industrial transformation will be increasingly important as pressure from climate policy via global CO2-pricing is unlikely in the short term. Current or enhanced indicators do not fully capture industrial transformation and are not recommended. Future research should focus on defining indicators to estimate energy use and emissions along industrial value chains in climate policy contexts.
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| 7. |
- Pacini, Henrique, 1982-
(författare)
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The Development of Bioethanol Markets under Sustainability Requirements
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis is a theoretical and empirical examination of the developmentof bioethanol markets since 2005 when sustainability regulations forbiofuels were introduced globally. The experiences of Brazil and Sweden,and the influence of European regulations on the development ofbioethanol markets receive special attention. The work is based onprimary and secondary data sources gathered between 2009 and 2014,including interviews, field research, data from public and private sources,as well as an extensive literature review. The thesis uses case examples ofcountries that have adopted bioethanol as a transport fuel, such as Braziland Sweden.The research is structured using a bottom-up approach, and addressesthree specific angles of the complex issue of how bioethanol marketshave developed under sustainability requirements.The first part introduces an economic sustainability view of ethanol. Thecharacteristics of bioethanol fuel are presented together with conceptsand a theoretical framework for analysing biofuel sustainability. Policytools are also discussed, particularly those used to introduce fuel ethanolin the transport sector. The discussion is centred on the competitionbetween ethanol and gasoline, considering the hypothesis that consumersare sensitive to prices and tend to choose fuels based on their cost-perenergyunit. The analysis is supported by the case examples of Brazil andSweden, with special focus on the delicate balance between fueleconomies of bioethanol and gasoline systems in the face of differentways oil products are priced in those countries. Findings show thatdrivers tend to choose between bioethanol (E85/E100) or gasoline (E5-E25) depending on the relative prices between the two fuels. Theresearch results suggest that different pricing strategies for bioethanoland gasoline affect how consumers perceive the attractiveness of eachfuel. The examples of E100 in Brazil and E85 in Sweden provide insightson the elastic consumer behaviour that new markets may experience,serving to guide strategies in different contexts.The second part of this work bridges experiences in national contextswith the recent trend for biofuel sustainability regulation in internationalmarkets. Based on the hypothesis that the ethanol industry is responsiveto sustainability regulations, an examination of the development of theiiBrazilian bioethanol industry is carried out. This provides a comparisonframework drawing patterns between the industry's reaction to nationalregulations (past) and international regulations (recent). For this purpose,a comparison between the European sustainability requirements forethanol and the industry’s status quo is explored. Findings show that theEU sustainability criteria for biofuels are likely to have three effects onthe bioethanol industry: (i) compliance through incrementalimprovements in sustainability practices and certification; (ii) riskdiversification by engaging in multi-output production models; and (iii)market leakage towards less-regulated markets.The third part of the thesis brings together the first two parts. Itexamines how in a fuel competition context, the incorporation of costsrelated to sustainability certification can change the attractiveness ofhigh-bioethanol blends for consumers. The model of sustainabilityadopted by major international markets is based on regulations enforcedby mandatory certification. As biofuel market share increased, producerswere faced with costs for sustainability certification in order to obtainmarket access. While it was expected that ‘sustainably’ produced biofuelswould be rewarded with higher prices in the EU, this work found thatprice premiums for ethanol have in general been very small or inexistent,with certified fuels becoming the new norm in the market. New costsbrought into the market through sustainability certification can make itdifficult to balance between national policies heavily reliant on consumerchoice between fuels (and associated price-elasticities), and thedeployment of high blends of ethanol, such as E100 and E85.By analysing the three aspects (consumer behaviour and marketdynamics for ethanol in Brazil and Sweden, the introduction ofsustainability criteria for biofuels, and the implications of sustainabilityfor consumer choice between fuels) this work seeks to increaseunderstanding of the highly complex issue of biofuel market formationin the face of sustainability requirements. The key finding is thatsustainability certification has a cost, which needs to be orchestrated withother sectors of the economy to achieve the desired objectives. Thisthesis suggests that crucial areas of economic and environmentalsustainability have been often dealt with separately in biofuelpolicymaking, which has created weaknesses that deserve attention infuture policy efforts in order to improve biofuel systems.
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| 8. |
- Xylia, Maria
(författare)
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Is energy efficiency the forgotten key to successful energy policy? : Investigating the Swedish case
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sweden aims to become one of the first fossil-free welfare countries in the world. In 2009, specific energy and climate policy targets were announced for 2020, which exceed the ambition of respective EU targets in some areas. The overarching objective of the thesis is to understand the role of energy efficiency in Swedish energy and climate policy frameworks, and identify the gaps that need to be addressed. In this context, energy efficiency is recognized as a challenge to address. Yet, there are reasons to believe that it is not being pursued with the same dedication as other energy and climate-related targets.This hypothesis is tested using Mixed Methods research, with cases on different sectors of the Swedish economy, namely energy intensive industry and public bus transport, as well as comparisons with energy efficiency within the EU-28. With the help of abductive reasoning, the observations are inferred to an explanation, and common themes for Swedish energy efficiency policies emerge.The evidence indicates that energy efficiency has received lower priority than other energy and climate policies. This is demonstrated by the conflict between energy efficiency, emission reduction and renewable energy targets, for example in the case of public transport. There is generally a mismatch between targets and the instruments in place. Thus more attention should be given to energy efficiency and its potential benefits for the Swedish energy system.Opportunities for energy efficiency improvements are not being fully realized, but new policy initiatives could provide the necessary support to harness the potential. In-depth evaluation of new policy instruments should be integrated in the policy-making process, in order to provide a clear picture of costs versus benefits. An example is given with a Cost-Benefit Analysis for energy efficiency obligations targeting the Swedish energy intensive industry.Simplicity and transparency in the introduction and monitoring of new instruments need to be sought for. Energy efficiency should be given first priority in relation to other energy and climate targets. The basis for future policies should be grounded now in order for energy efficiency to become the key for successful Swedish energy policy.
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| 9. |
- Broberg Viklund, Sarah, 1983-
(författare)
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System studies of the use of industrial excess heat
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Energy, materials, and by-products, can be exchanged between companies, having positive effects in the form of improved resource efficiency, environmental benefits, and economic gains. One such energy stream that can be exchanged is excess heat, that is, heat generated as a by-product during, for example, industrial production. Excess heat will continue to play an important role in efforts to reduce greenhouse gas (GHG) emissions and improve energy efficiency. Using excess heat is therefore currently emphasized in EU policy as a way to reach EU climate targets.This thesis examines the opportunities of manufacturing industries to use industrial excess heat, and how doing so can positively affect industry, society, and the climate. Since different parts of the energy system are entangled, there is an inherent complexity in studying these systems and introducing excess heat in one part of the energy system may influence other parts of the system. This analysis has accordingly been conducted by combining studies from various perspectives, by applying both quantitative and qualitative methods and covering a broad range of aspects, such as technical possibilities as well as climate, policy, economics, and resource aspects.The results identify several opportunities and benefits accruing from excess heat use. Although excess heat is currently partly used as a thermal resource in district heating in Sweden, this thesis demonstrates that significant untapped excess heat is still available. The mapping conducted in the appended studies identifies excess heat in different energy carriers, mainly low-temperature water. Analysis of excess heat use in different recovery options demonstrated greater output when using excess heat in district heating than electricity production. Optimizing the trade-offs in excess heat used in a district heating network, heat-driven cooling, and electricity production under different energy market conditions while minimizing the system cost, however, indicated that the attractiveness of excess heat in district heating depends on the type of heat production in the system. Viewing excess heat as a low-cost energy source also makes it economically interesting, and creates opportunities to invest in excess heat-recovery solutions. Excess heat is often viewed as CO2 neutral since unused excess heat may be regarded as wasted energy. The GHG mitigation potential of using excess heat, however, was found to be ambiguous. The appended studies demonstrate that using excess heat for electricity production or for applications that reduce the use of electricity reduces GHG emissions. The effects of using excess heat in district heating, on the other hand, depend on the energy market development, for example, the marginal electricity production and marginal use of biomass, and on the type of district heating system replaced. The interviews performed reveal that energy policy does influence excess heat use, being demonstrated both to promote and discourage excess heat use. Beyond national energy policies, internal goals and core values were identified as important for improved energy efficiency and increased excess heat use.
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| 10. |
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