| 1. |
- Ahlgren, Erik, 1962, et al.
(författare)
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Biokombi Rya - slutrapporter från ingående delprojekt
- 2007
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Inom projektet Biokombi Rya har ett flertal olika forskargrupper samarbetat för att studera system¬effekterna av förgasning av biobränsle ur olika aspekter. Syftet med projektet är att öka kunskapen om biobränsleförgasning i Sverige samt att utreda förutsättningar för att sådana anläggningar ska vara ekonomiskt och miljömässigt intressanta. En referensgrupp har varit kopplad till projektet där förutsättningar, resultat och slutsatser har behandlats.I denna underlagsrapport har slutrapporterna från projektets delprojekt samlats. De beskriver förutsättningar, metodansatser, använda data och resultat utförligt och utgör på så sätt ett viktigt komplement till den mer övergripande beskrivningen i projektets syntesrapport. De delrapporter som ingår har valts för att täcka in samtliga delar av projektet som är av allmänt intresse. Projektresultat som publicerats på annat sätt berörs dock mer kortfattat.Projektet Biokombi Rya har pågått under två år (2005-2006) och drivits av Chalmers EnergiCentrum. Förutom de omfattande analysinsatser som författarna till denna rapport står för, har Avdelningen för kemisk teknologi vid KTH, Siemens Industrial Turbines AB och Göteborg Energi AB bidragit med expertstöd. CIT Industriell Energianalys, med undertecknad som projektledare, har stått för projektledning och koordination.Projektet har finansierats av Energimyndigheten, Göteborg Energis forsknings¬stiftelse samt Göteborg Energi AB.
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| 2. |
- Andersson, Björn A., 1968, et al.
(författare)
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Materials constraints in a global energy scenario based on thin-film solar cells
- 1998
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Ingår i: Energy. - 0360-5442. ; 23, s. 407-411
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Tidskriftsartikel (refereegranskat)abstract
- Harnessing solar energy by using photovoltaic cells has the potential to become a major CO2-free energy source. Materials requirements for the solar cells based on four types of thin-film photovoltaics have been estimated and compared with global reserves, resources and annual refining. The use of solar cells based on Cd, Ga, Ge, In, Ru, Se and Te as a major energy-supply technology has severe resource constraints. Other systems such as a-Si without Ge and crystalline silicon do not involve such constraints. For some of these metals, there is the risk of enhanced, environmentally deleterious concentrations in the ecosphere due to leakage from manufacturing, use or waste handling.
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| 3. |
- Andersson, Sara-Linnea, et al.
(författare)
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Plug-in Hybrid Electric Vehicles as Regulating Power Providers - Case Studies of Sweden and Germany
- 2010
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Ingår i: Energy Policy. - : Elsevier BV. - 0301-4215. ; 38:6, s. 2751-2762
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Tidskriftsartikel (refereegranskat)abstract
- This study investigates plug-in hybrid electric vehicles (PHEVs) as providers of regulating power in the form of primary, secondary and tertiary frequency control. Previous studies have shown that PHEVs could generate substantial profits while providing ancillary services. This study investigates under what conditions PHEVs can generate revenues using actual market data, i.e. prices and activations of regulating power, from Sweden and Germany from four months in 2008. PHEV market participation is modelled for individual vehicles in a fleet subject to a simulated movement pattern. Costs for infrastructure and vehicle-to-grid equipment are not included in the analysis. The simulation results indicate that maximum average profits generated on the German markets are in the range 30–80 h per vehicle and month whereas the Swedish regulating power markets give no profit.In addition, an analysis is performed to identify strengths, weaknesses, opportunities, and threats (SWOT) of PHEVs as regulating power providers. Based on the simulation results and the SWOT analysis, characteristics for an ideal regulating power market for PHEVs are presented.
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| 4. |
- Björnsson, Lars Henrik, 1984, et al.
(författare)
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Electrification of the two-car household: PHEV or BEV?
- 2017
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Ingår i: Transportation Research, Part C: Emerging Technologies. - : Elsevier BV. - 0968-090X. ; 85, s. 363-376
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Tidskriftsartikel (refereegranskat)abstract
- In previous works, we have shown two-car households to be better suited than one-car households for leveraging the potential benefits of the battery electric vehicle (BEV), both when the BEV simply replaces the second car and when it is used optimally in combination with a conventional car to overcome the BEV’s range limitation and increase its utilization. Based on a set of GPS-measured car movement data from 64 two-car households in Sweden, we here assess the potential electric driving of a plug-in hybrid electric vehicle (PHEV) in a two-car household and compare the resulting economic viability and potential fuel substitution to that of a BEV. Using estimates of near-term mass production costs, our results suggest that, for Swedish twocar households, the PHEV in general should have a higher total cost of ownership than the BEV, provided the use of the BEV is optimized. However, the PHEV will increasingly be favored if, for example, drivers cannot or do not want to optimize usage. In addition, the PHEV and the BEV are not perfect substitutes. The PHEV may be favored if drivers require that the vehicle be able to satisfy all driving needs (i.e., if drivers don’t accept the range and charge-time restrictions of the BEV) or if drivers requires an even larger battery in the BEV to counter range anxiety. We find that, given a particular usage strategy, the electric drive fraction (EDF) of the vehicle fleet is less dependent on whether PHEVs or BEVs are used to replace one of the conventional cars in two-car households. Instead, the EDF depends more on the usage strategy, i.e., on whether the PHEV/BEV is used to replace the conventional car with the higher annual mileage (“the first car”), the less used car (“the second car”), or is used flexibly to substitute for either in order to optimize use. For example, from a fuel replacement perspective it is often better to replace the first car with a PHEV than to replace the second with a BEV.
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| 5. |
- Björnsson, Lars Henrik, 1984, et al.
(författare)
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Objective functions for plug-in hybrid electric vehicle battery range optimization and possible effects on the vehicle fleet
- 2018
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Ingår i: Transportation Research, Part C: Emerging Technologies. - : Elsevier BV. - 0968-090X. ; 86, s. 655-669
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Tidskriftsartikel (refereegranskat)abstract
- While a hybrid electric vehicle (HEV) mainly runs on the same fuel as a conventional combustion engine, a plug-in hybrid electric vehicle (PHEV) has the potential to replace most of that fuel with electricity from the grid. Further, the driving-range limitations associated with a pure battery electric vehicle (BEV) do not apply to the PHEV. This makes the PHEV an interesting option for reducing greenhouse gas (GHG) emissions and local air pollutants as well as energy dependence, without sacrificing performance. However, how large fuel reduction that could be expected from PHEVs strongly depends on the battery range and driving and charging patterns (Björnsson and Karlsson, 2015). To maximize fuel reduction, battery capacity should be designed to reach a high share of electric driving. However, maximizing fuel reduction might not be the main objective for all stakeholders when optimizing battery range. Car owners could be more interested in reaching a low total cost of ownership (TCO), while manufacturers might focus on a battery range that suits as many potential buyers as possible. In this study, we analyze how the optimal battery range for the PHEV and the resulting vehicle fleet properties vary with the choice of objective function under various techno-economic conditions and policy options.
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| 6. |
- Björnsson, Lars Henrik, 1984, et al.
(författare)
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Plug-in hybrid electric vehicles: How individual movement patterns affect battery requirements, the potential to replace conventional fuels, and economic viability
- 2015
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 143, s. 336-347
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Tidskriftsartikel (refereegranskat)abstract
- Using GPS data logged for a representative sample of individual vehicles in private use, we assess the viability of plug-in hybrid electric vehicles (PHEVs) in Sweden for a wide range of techno-economic conditions. We determine requirements for PHEVs with the aid of a simple parameterization used to analyze the GPS data covering number of trips, driving distance per trip, and parking times, logged for 30 days or longer, for 432 conventional Swedish cars. Good opportunities for charging and regular distances traveled between rechargings increase the potential for battery-powered driving and, along with a high annual mileage, enhance the viability of the PHEV. Therefore, commuters are likely to be the first drivers for whom the PHEV will be cost-effective. Making charging infrastructure available at work places would enhance the opportunity for this group of early adopters, as we show that charging while at work is comparable at the-initial stage to halving the marginal battery costs for the average commuter.
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| 7. |
- Björnsson, Lars Henrik, 1984, et al.
(författare)
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The potential for brake energy regeneration under Swedish conditions
- 2016
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 168, s. 75-84
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Tidskriftsartikel (refereegranskat)abstract
- The ability to regenerate energy when braking is a valuable advantage of hybrid and fully electric vehicles. The regeneration potential mainly depends on how a car is driven and on the capacity of the drivetrain. Detailed studies of the regeneration potential based on brake energy in real-world driving are needed to better understand the potential gains of car-electrification, since test cycles do not take individual driving characteristics or route elevation into account. This study uses a model of a normalized vehicle and a highly detailed and representative data set of individual car movements including elevation to analyze the potential for energy regeneration in cars when driven under current real-world Swedish conditions.The ultimate energy regeneration potential (defined as the braking energy at the wheels) varies by about a factor of six among individual movement patterns, with an average of 0.033 kW h/km, corresponding to 27% of the total average energy supplied at the wheels. Earlier studies have shown a higher energy regeneration potential per km for cars driving under urban conditions with low average velocity and many starts and stops. Our results confirm this but also point out that a low average velocity and a high share of city driving are not very well correlated with the yearly energy savings; for this the yearly mileage is a more important indicator. This suggests that drivers who rack up the miles should be targeted as potential early adopters of regenerative technologies rather than city drivers per se. The results from real-world driving are compared to the NEDC and WLTP test cycles.
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| 8. |
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| 9. |
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| 10. |
- Grahn, Maria, 1963, et al.
(författare)
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Utilising excess power: the case of electrofuels for transport
- 2014
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Ingår i: Systems Perspectives on Renewable Power 2014. - 9789198097405 ; , s. 128-137
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Bokkapitel (övrigt vetenskapligt/konstnärligt)abstract
- If the production of electricity at a given moment in time is higher than demandwe may talk about excess electricity.1 It is possible to store excess electricity andstorage solutions might be essential for achieving very high renewable energyshares in the energy system. The most common purpose for storing electricity isof course to convert the stored energy back to electricity when needed. Currentlythere are not many mature alternatives for seasonal energy storage. Pumpedhydro, hydrogen and compressed air are facing challenges with geographicaldistribution and ecological footprint, technical limitations or low density.2 Anotheroption is to convert electricity into an energy carrier that can be used for otherpurposes, and not just as a medium for electricity storage. One possibility is to useperiods of excess electricity for the production of carbon-based synthetic fuels,so called electrofuels,3 that can be used for various purposes, e.g. for heating,as a transportation fuel or in the chemical industry for the production of plastics,textiles, medicine and fertilizers. One challenge, common to all energy storage technologies, is to be economicallyviable in spite of the fact that excess, or low priced, electricity will likely be availableonly a fraction of the time. This chapter aims to explore the challenges andopportunities of using electrofuels to utilise excess electricity. Production processesare described and costs are estimated to underpin a discussion on what isrequired to make electrofuels competitive with gasoline.
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