| 1. |
- Arvizu, Dan, et al.
(författare)
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Summary for Policy Makers: Intergovernmental Panel on Climate Change Special Report Renewable Energy Sources (SRREN)
- 2011
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The Working Group III Special Report on Renewable Energy Sources and Climate Change Mitigation (SRREN) presents an assessment of the literature on the scientific, technological, environmental, economic and social aspects of the contribution of six renewable energy (RE) sources to the mitigation of climate change. It is intended to provide policy relevant information to governments, intergovernmental processes and other interested parties. This Summary for Policymakers provides an overview of the SRREN, summarizing the essential findings. The SRREN consists of 11 chapters. Chapter 1 sets the context for RE and climate change; Chapters 2 through 7 provide information on six RE technologies, and Chapters 8 through 11 address integrative issues.
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| 2. |
- Arvizu, Dan, et al.
(författare)
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Technical Summary
- 2011
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Ingår i: IPCC Special Report on Renewable Energy Sources and Climate Change Mitigation.
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Bokkapitel (refereegranskat)
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| 3. |
- de Jong, Sierk, et al.
(författare)
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Cost optimization of biofuel production – The impact of scale, integration, transport and supply chain configurations
- 2017
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Ingår i: Applied Energy. - : Elsevier Ltd. - 0306-2619 .- 1872-9118. ; 195, s. 1055-1070
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Tidskriftsartikel (refereegranskat)abstract
- This study uses a geographically-explicit cost optimization model to analyze the impact of and interrelation between four cost reduction strategies for biofuel production: economies of scale, intermodal transport, integration with existing industries, and distributed supply chain configurations (i.e. supply chains with an intermediate pre-treatment step to reduce biomass transport cost). The model assessed biofuel production levels ranging from 1 to 150 PJ a−1 in the context of the existing Swedish forest industry. Biofuel was produced from forestry biomass using hydrothermal liquefaction and hydroprocessing. Simultaneous implementation of all cost reduction strategies yielded minimum biofuel production costs of 18.1–18.2 € GJ−1 at biofuel production levels between 10 and 75 PJ a−1. Limiting the economies of scale was shown to cause the largest cost increase (+0–12%, increasing with biofuel production level), followed by disabling integration benefits (+1–10%, decreasing with biofuel production level) and allowing unimodal truck transport only (+0–6%, increasing with biofuel production level). Distributed supply chain configurations were introduced once biomass supply became increasingly dispersed, but did not provide a significant cost benefit (<1%). Disabling the benefits of integration favors large-scale centralized production, while intermodal transport networks positively affect the benefits of economies of scale. As biofuel production costs still exceeds the price of fossil transport fuels in Sweden after implementation of all cost reduction strategies, policy support and stimulation of further technological learning remains essential to achieve cost parity with fossil fuels for this feedstock/technology combination in this spatiotemporal context. © 2017 The Authors
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| 4. |
- 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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| 5. |
- Lako, P., et al.
(författare)
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Offshore wind energy
- 2010
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Ingår i: Technological Learning in the Energy Sector - Lessons for Policy, Industry and Science.
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 6. |
- Londo, Marc, et al.
(författare)
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Eyes on the track, mind on the horizon: The REFUEL EU Road Map for biofuels
- 2008
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Ingår i: Proceedings of the 16th European Biomass Conference & Exhibition - From research to industry and markets, Feria Valencia, Spain, 2-6 June 2008.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The current hot debate on biofuels calls for a balanced and realistic long-term strategy for biofuels. The REFUEL project provides several ingredients for such a strategy. Analyses in this project indicate that domestically produced biofuels can cover a significant share of EU fuel demand in the coming decades, with the EU-12 new member states and Ukraine as most promising regions. This potential can be realised with residual streams and on existing agricultural land, without conversion of e.g. nature reserves. Second-generation biofuels are essential for the long-term success of biofuels due to their superior performance in many ways. But generally, the key challenge for the near future would be how to enhance the development of biofuels in a responsible way, i.e. stimulating the production chains with the best performance, and preventing negative impacts e.g., by paying careful attention to possible system impacts of biofuel production such as indirect land use changes and rising food prices. Finally, 2nd generation biofuels require specific policy: the precursor role of 1st generation is overrated, both in technical terms as well as in their role as market precursors. When it comes to synergies, 2nd generation biofuels might benefit more from other developments in the energy sector, such as initiatives in co-firing of biomass for (heat and) power, than from 1st generation biofuels, also because of the public resistance that the latter induce.
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| 7. |
- Londo, Marc, et al.
(författare)
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The REFUEL EU road map for biofuels in transport: Application of the project’s tools to some short-term policy issues
- 2010
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 34:2, s. 244-250
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Tidskriftsartikel (refereegranskat)abstract
- The current hot debate on biofuels calls for a balanced and realistic long-term strategy forbiofuels. The REFUEL project provides several ingredients for such a strategy. Analyses inthis project indicate that domestically produced biofuels can cover a significant share of EUfuel demand in the coming decades, with the EU-12 new member states and Ukraine asmost promising regions. This potential can be realised with residual streams and onexisting agricultural land, without conversion of e.g. nature reserves. Second generationbiofuels are essential for the long-term success of biofuels due to their superior performancein many ways. But generally, the key challenge for the near future would be how toenhance the development of biofuels in a responsible way, i.e. stimulating the productionchains with the best performance, and preventing negative impacts e.g., by paying carefulattention to possible system impacts of biofuel production such as indirect land usechanges and rising food prices. Finally, 2nd generation biofuels require specific policy: theprecursor role of 1st generation is overrated, both in technical terms as well as in their roleas market precursors. When it comes to synergies, 2nd generation biofuels might benefitmore from other developments in the energy sector, such as initiatives in co-firing ofbiomass for (heat and) power, than from 1st generation biofuels, also because of the publicresistance that the latter induce.
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| 8. |
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| 9. |
- Truong, Nguyen Le, 1976-
(författare)
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District heat production under different environmental and social cost scenarios
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- District heat production systems (DHSs) are normally designed to meet the heat demand of customers at a minimum cost whilst fulfilling local and national regulations. Various factors influence the choice of district heat production units in a minimum-cost system. In this thesis, the performance of DHSs of different types were analyzed under a range of environmental and social cost scenarios. The scenarios include No tax using the bare cost of fuels without any taxes or fees, Swedish tax using Swedish taxes and fees on fuels, Social cost-550ppm using a carbon damage cost of US$30/t CO2, Social cost-BAU using a carbon damage cost of US$85/t CO2, and Renewable-based without using fossil fuels for energy purposes. DHSs were analyzed under varying conditions of scale, potential to co/poly-generate district heat with other products, and integration of new technologies currently being developed. The influence of end-use energy efficiency measures in district-heated buildings on DHSs was also analyzed.The cost optimal composition of a DHS depends on several factors including the scale, the load factor of the heat demand, the technologies used in the DHS, as well as the environmental and social costs. When environmental and social costs are considered, the co-generation of electricity is more cost-efficient than other options, except for small scale systems, for which heat-only production is more cost-efficient. Also, in a minimum-cost DHS, district heat production cost is about the same for all the environmental and social cost scenarios except for the No tax scenario. The district heat production cost of a small-scale DHS under the No tax scenario is lower than that of the same scale system under the other scenarios. However, a large-scale DHS under the No tax scenario gives higher district heat production cost than the same scale system under the other scenarios. The changed environmental and social costs vary the types and amount of fuel use as well as the value of co-generated products such as electricity, which consequently balances the district heat production cost.Renewable-based DHS using biomass is economically viable if environmental and social costs of using fossil fuels are taken into account. A fully biomass-based DHS can be as primary energy-efficient as other DHSs analyzed. Typically, biomass-based co-generation of district heat and electricity combined with stand-alone production of biomotor fuels is more cost- and primary energy-efficient than the co-generation of district heat and biomotor fuels combined with stand-alone production of electricity. The integration of non-fuel renewable technologies such as solar water heating can further reduce the use of biomass in a cost-efficient way for small-scale DHSs in combination with high fuel costs.The characteristics of a DHS influence the effectiveness of end-use energy efficiency measures in district heated buildings. Although end-use energy efficiency measures change the final energy use, the composition and operation of the supply system determine the amount and types of fuel savings. Supply systems with different composition and operation give varying primary energy savings per unit of reduced end-use energy from an energy efficiency measure. The primary energy savings due to end-use heat saving measures in buildings is much higher for heat-only production units than for co/poly-generation units, because heat savings in co/poly-generation systems also reduce the potential production of co-products. Therefore, the analysis of both demand and supply sides of district heating systems as well as their interaction is crucial for the evaluation of the consequences of end-use energy efficiency measures in district-heated buildings. Actually, energy efficiency measures in district-heated buildings typically increase the overall heat load factor for a DHS which reduces the operating cost per unit of produced district heat in existing system and the total cost when existing district heat production units have to be renewed or changed. The connection of new energy-efficient buildings that balances the energy efficiency improvement in existing district-heated buildings appears to be an optimal option for a DHS.
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| 10. |
- Turkenburg, Wim C, et al.
(författare)
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Renewable Energy Technologies
- 2000
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Ingår i: World energy assessment: energy and the challenge of sustainability. - 9211261260 ; , s. 219-272
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Bokkapitel (refereegranskat)abstract
- In 1998 renewable energy sources supplied 56 ± 10 exajoules,or about 14 percent of world primary energy consumption. Thesupply was dominated by traditional biomass (38 ± 10 exajoules a year. Other major contributions came from large hydropower (9 exajoules a year) and from modern biomass (7 exajoules). The contribution of all other renewables — small hydropower, geothermal, wind, solar, and marineenergy — was about 2 exajoules. That means that the energy supply from new renewables was about 9 exajoules (about 2 percent of world consumption). The commercial primary energy supply from renewable sources was 27 ± 6 exajoules (nearly 7 percent of world consumption), with 16 ± 6 exajoules from biomass. Renewable energy sources can meet many times the present world energy demand, so their potential is enormous. They can enhance diversity in energy supply markets, secure long-term sustainable energy supplies, and reduce local and global atmospheric emissions. They can also provide commercially attractive options to meet specific needs for energy services (particularly in developing countries and rural areas), create new employment opportunities, and offer possibilities for local manufacturing of equipment. There are many renewable technologies. Although often commerciallyavailable, most are still at an early stage of development and not technically mature. They demand continuing research, development, and demonstration efforts. In addition, few renewable energy technologies can compete with conventional fuels on cost, except in some niche markets. But substantial cost reductions can be achieved for most renewables, closing gaps and making them more competitive. That will require further technology development and market deployment — and boosting production capacities to mass production. For the long term and under very favourable conditions, the lowest cost to produce electricity might be $0.01–0.02 a kilowatt-hour for geothermal, $0.03 a kilowatt-hour for wind and hydro, $0.04 a kilowatt-hour for solar thermal and biomass, and $0.05–0.06 a kilowatt-hour for photovoltaics and marine currents. The lowest cost to produce heat might be $0.005 a kilowatt-hour for geothermal, $0.01 a kilowatt-hour for biomass, and $0.02–0.03 a kilowatt-hour for solar thermal. The lowest cost to produce fuels might be $1.5 a gigajoule for biomass, $6–7 a gigajoule for ethanol, $7–10 a gigajoule for methanol, and $6–8 a gigajoule for hydrogen. Scenarios investigating the potential of renewables reveal that they might contribute 20–50 percent of energy supplies in the second half of the 21st century. A transition to renewables-based energy systems would have to rely on: Successful development and diffusion of renewable energy technologies that become more competitive through cost reductions from technological and organisational developments. Political will to internalise environmental costs and other externalities that permanently increase fossil fuel prices. Many countries have found ways to promote renewables. As renewable energy activities grow and require more funding, the tendency in many countries is to move away from methods that let taxpayers carry the burden of promoting renewables, towards economic and regulatory methods that let energy consumers carry the burden.
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