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| 2. |
- Azar, Christian, 1969, et al.
(författare)
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Brazilian Ethanol has the Edge.
- 2007
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Ingår i: Financial Times.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 3. |
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| 4. |
- Cebrat, Gerfried, et al.
(författare)
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Methods to determine robust innovation paths for electric vehicle technology
- 2009
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Ingår i: 24th International Battery, Hybrid and Fuel Cell Electric Vehicle Symposium and Exhibition 2009, EVS 24. - 9781615674558 ; 4, s. 2345-2354
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Konferensbidrag (refereegranskat)abstract
- The following paper introduces a structured approach assessing the probability for the success of specific technologies increasing the endurance/autonomy of BEV's (Battery Electric Vehicles). Apart from range extenders, flow batteries (redox batteries as one variant) which might be refilled with electrolyte similar to conventional vehicles and technological improvements, the exchange of batteries is a method allowing BEV's similar ranges and similar usability like vehicles with internal combustion engines as they are currently used. The suggested way for the investigation into the success of the concept holds a two fold approach: Mapping the innovation: Enumerating the influencing factors Assessing: In-depth research of acceptance In step one influence analysis (causal loop) is applied to determine the most active factors and the system dynamics. In step two a multi criteria decision analysis is employed in order to quantify the potential impact of the factors/characteristics on the probability of the success of the concepts. The two step methodology is presented for the battery exchange system (swappable battery), because for this system it is easiest to determine the technological aspects being purely mechanical and also the market impact based on the pre-existing knowledge of the facts. The range extenders and flow batteries still need technological research clarifying the operational characteristics of an industrialised concept before a robust assessment may be conducted. The paper anticipates the acceptance of the first mentioned concepts and enumerates the questions that have to be solved in order to allow a successful use case. The closing chapter analyses the influence of paradigm change on the assessment introducing uncertainties. In this respect it is shown how in depth foresight studies may reduce the risk for the innovator by introducing the actors/users introducing criteria for success and failure.
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| 5. |
- Grahn, Maria, 1963, et al.
(författare)
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Biomass for heat or as transportation fuel? - a comparison between two model based studies
- 2007
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Ingår i: Biomass & Bioenergy. ; 31, s. 747-758
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Tidskriftsartikel (refereegranskat)abstract
- In two different energy economy models of the global energy system, the cost-effective use of biomass under a stringent carbon constraint has been analyzed. Gielen et al. conclude that it is cost-effective to use biofuels for transportation, whereas Azar et al. find that it is more cost-effective to use most of the biomass to generate heat and process heat, despite the fact that assumptions about the cost of biofuels production is similar in the models. In this study, we compare the two models with the purpose of finding an explanation for these different results. It was found that both models suggest that biomass is most cost-effectively used for heat production for low carbon taxes (below 50–100 USD/tC, depending on the year in question). But for higher carbon taxes, the cost-effective choice reverses in the BEAP model, but not in the GET model. The reason for this is that GET includes hydrogen from carbon-free energy sources as a technology option, whereas that option is not allowed in the BEAP model. In all other sectors, both models include carbon-free options above biomass. Thus, with higher carbon taxes, biomass will eventually become the cost-effective choice in the transportation sector in BEAP, regardless of its technology cost parameters.
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| 6. |
- Grahn, Maria, 1963, et al.
(författare)
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Biomass for heat or as transportation fuel? A comparison between two model-based studies
- 2007
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 31:11-12, s. 747-758
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Tidskriftsartikel (refereegranskat)abstract
- In two different energy economy models of the global energy system, the cost-effective use of biomass under a stringent carbon constraint has been analyzed. Gielen et al. conclude that it is cost-effective to use biofuels for transportation, whereas Azar et al. find that it is more cost-effective to use most of the biomass to generate heat and process heat, despite the fact that assumptions about the cost of biofuels production is similar in the models. In this study, we compare the two models with the purpose of finding an explanation for these different results. It was found that both models suggest that biomass is most cost-effectively used for heat production for low carbon taxes (below 50-100 USD/tC, depending on the year in question). But for higher carbon taxes, the cost-effective choice reverses in the BEAP model, but not in the GET model. The reason for this is that GET includes hydrogen from carbon-free energy sources as a technology option, whereas that option is not allowed in the BEAP model. In all other sectors, both models include carbon-free options above biomass. Thus, with higher carbon taxes, biomass will eventually become the cost-effective choice in the transportation sector in BEAP, regardless of its technology cost parameters. © 2007 Elsevier Ltd. All rights reserved.
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| 7. |
- Grahn, Maria, 1963, et al.
(författare)
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BIOMASS FOR HEAT OR AS TRANSPORTATION FUEL? A COMPARISON BETWEEN TWO MODEL BASED STUDIES
- 2005
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Ingår i: The 14th European Conference and Technology Exhibition on Biomass for Energy, Industry and Climate in Paris, 17-21 October.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- In two different energy economy models of the global energy system, the cost-effective use of biomass under a stringent carbon constraint has been analyzed. Gielen et al. conclude that it is cost-effective to use biofuels for transportation, whereas Azar et al. find that it is more cost-effective to use most of the biomass to generate heat and process heat, despite the fact that assumptions about the cost of biofuels production is rather similar in the models. In this study, we compare the two models with the purpose to find an explanation for these different results. It is found that both models suggest that biomass is most cost-effectively used for heat production for low carbon taxes (below 50-100 USD/tC, depending on the year in question). But for higher carbon taxes the cost effective choice reverses in the BEAP model, but not in the GET model. The reason for that is that GET includes hydrogen from carbon free energy sources as a technology option, whereas that option is not allowed in the BEAP model. In allother sectors, both models include carbon free options above biomass. Thus with higher carbon taxes, biomass will eventually become the cost-effective choice in the transportation sector in BEAP, regardless of its technology cost parameters.
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| 8. |
- Grahn, Maria, 1963
(författare)
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Cost-effective fuel and technology choices in the transportation sector in a future carbon constrained world: Results from the Global Energy Transition (GET) model
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis analyzes future fuel and technology choices focusing on transport in a carbon constrained world. The analysis tool used in all five appended papers is the cost-minimizing Global Energy Transition (GET) model. Paper I analyzes cost-effective fuel and technology choices for passenger vehicles under a variety of vehicle cost-assumptions and how these choices depend on technology paths in the electricity sector. We find that cost estimates as well as the availability of carbon capture and storage technology and concentrating solar power have a substantial impact, ranging from a dominance of hydrogen to a dominance of electricity. Paper II analyzes the cost-effectiveness of biofuels for transportation, assuming that industrialized regions start reducing their CO2 emissions some decades ahead of developing regions. We find that biofuels may play a more important role for transportation in industrialized regions if these regions assume their responsibilities and reduce emissions before developing regions start reducing theirs, compared to the case in which all countries take action under a global cap and trade emissions reduction regime. Paper III analyzes how policy instruments aimed at increasing the use of biofuels for transportation in industrialized regions affect CO2 emissions in industrialized and developing regions. We find that such policy instruments may lead to avoided emissions in industrialized regions, especially during the first 50 years, and in a few specific cases in the developing regions, too. However, in the majority of cases, such a biofuels policy leads to increased emissions in the developing regions, i.e., to “carbon leakage.” Paper IV analyzes why two global energy systems models reach different results on the cost-effectiveness of biofuels, although the models have strong similarities. We find biomass most cost-effectively used for heat production at low CO2 taxes in both models. Biomass allocation at higher CO2 taxes may depend on whether CO2-neutral hydrogen and/or electricity are assumed available for the transportation sector at sufficiently low cost. Paper V investigates prices and costs in the GET model, and how these change over time, to get a deeper understanding of why biofuels generally are not a cost-effective transportation fuel choice in the model. We compare the total cost per km for each fuel choice, based on the primary energy prices and carbon tax generated by the model. We find that the required carbon tax level for biofuels to become cost-effective, compared to fossil-based fuels, is a “moving target.” The required tax level increases with an increase in carbon taxes, since the latter increases the price of biomass energy in the model.
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| 9. |
- Grahn, Maria, 1963, et al.
(författare)
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Cost effective fuel choices in the transportation sector under different international climate regimes – results from a regionalized version of the global energy transition model, GET-R
- 2007
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Ingår i: Proceedings Book of 15th European Biomass Conference and Exhibition from Research to Market Deployment, Industry and Climate, Berlin, Germany, 7-11 May.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- ABSTRACT: The aim of this study is to analyze cost-effective fuel choices in the transportation sector, given that the industrialized regions take the lead in mitigating global warming. The analysis is carried out with a regionalized version of the global energy transition model, GET-R 6.0. It is a linear programming model and it has three end-use sectors: electricity, heat and transportation fuels. It is set up to generate the energy supply mix that meets exogenously given energy demands and carbon constraints at the lowest global energy system cost under different international climate regimes. Two different CO2 reduction scenarios are applied, both meeting an atmospheric CO2 concentration target of 450 ppm by the year 2100. In the first scenario, global CO2 emissions trading are allowed. In the second scenario, it is assumed that emission reductions are not tradable across regions and that the industrialized regions take the lead in mitigating global warming. They start to reduce their CO2 emissions from 2010 while developing regions wait several decades. In this second scenario CO2 emissions are assumed to meet an equal per capita distribution of 1.0 tC/capita, in all six regions, in 2050 and then jointly follow an emission reduction path, towards 0.17 tC/capita (equal to a global emission of 2 GtC) in 2100. The results show that biofuels for transport in industrialized regions reach a mean value of 16% of the total fuel use over this century in the second scenario compared to less than half of that, 6%, in the first scenario.
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| 10. |
- Grahn, Maria, 1963
(författare)
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Cost-effective fuel choices in the transportation sector under stringent CO2-emission reduction targets - Global energy systems modelling
- 2006
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis analyzes the worlds future energy supply in general, and cost-effective fuel choices in the transportation sector in particular, under stringent CO2 constraints. The analysis is carried out with the help of a global energy systems model (GET), developed and modified specifically for each project. GET is a linear programming model and it has three end-use sectors: electricity, heat and transportation fuel. It is set up to generate the energy supply mix that would meet exogenously given energy demand levels at the lowest global cost. This thesis consists of the following three papers (i) an analysis of why two similar global energy systems models, GET and BEAP, give different results as to whether biofuels will become cost-effective in the transportation sector, (ii) an analysis of cost effective fuel choices in a regionalized version of the GET model and (iii) an analysis of the cost dynamics in the GET model in a further developed version of the model. Conclusions drawn within the scope of this thesis are that biomass is most cost-effectively used for heat production at low CO2 taxes, up to about 75 USD/tC, as shown in both the GET and the BEAP model. The sector in which biomass is most cost-effectively used at higher CO2 taxes depends on assumed possible energy carriers and technologies. If hydrogen and/or electricity derived from carbon free energy sources will not be available in the transportation sector at sufficiently low costs, biofuels become an important option if low or zero carbon emissions are to be achieved. Thus, the long run future for the cost-effective transportation fuel choice is still in the open. Regionalizing the GET 1.0 model will not affect the overall pattern of transportation fuel choices, i.e. that gasoline/diesel remain for some decades in the transportation sector until the carbon constraint becomes increasingly stringent and that solar based hydrogen dominates by the end of this century. In paper III, we find that the required carbon tax level where biofuels become cost-efficient, compared to fossil based fuels, is evasive. The tax level moves upwards with increasing carbon taxes, since this leads to an increasing biomass primary energy price in the model.
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