Results 1 - 10 of 1141
Results 1 - 10 of 1141. Search took: 0.022 seconds
|Sort by: date | relevance|
[en] The widespread operation of internal combustion engine (ICE) vehicles has today become a great cause for concern due to the uncertainty of fossil fuel reserves, energy security issues, and numerous adverse environmental effects. Alternatives such as fuel cell vehicles, electric vehicles, hybrid vehicles, and biodiesel vehicles provide the possibility to ease some or all of these concerns. The fuel cell vehicle, however, offers an excellent combination of reducing ICE vehicle problems while maintaining the performance, driving range, and convenience that consumers require. This paper documents a comparative evaluation of an extremely important facet of the fuel cell vehicle: the energy storage system (ESS). Batteries and ultracapacitors, the two most common choices for an ESS, are compared qualitatively to illustrate the advantages and disadvantages of each. Also, a quantitative comparison is made to choose the best technology for a small fuel cell-powered SUV having the design objectives of high performance and high efficiency. Practical issues such as availability and cost are also considered. The results of the analysis indicate that a battery ESS provides the best combination of efficiency, performance, and cost for a present-day fuel cell vehicle design. Yet, if the anticipated cost reductions and improvements in the energy storage capabilities of ultracapacitors do occur, ultracapacitors will become a very strong contender for energy storage solutions of future fuel cell vehicles. (author)
[en] If battery packs for electric vehicles (EVs) and hybrid electric vehicles (HEVs) are to operate effectively in all climates, thermal management of the packs is essential. In this paper, we will review a systematic approach for designing and evaluating battery pack thermal management systems. A thermal management system using air as the heat transfer medium is less complicated than a system using liquid cooling/heating. Generally, for parallel HEVs, an air thermal management system is adequate, whereas for EVs and series HEVs, liquid-based systems may be required for optimum thermal performance. Further information on battery thermal management can be found on the Web site www.ctts.nrel.gov/BTM
[en] This paper outlined the status of the electric vehicle industry in Canada. While the low energy density of electric batteries has prevented the widespread adoption of electric-powered vehicles, new developments in nickel metal hydride (Ni-MH) batteries have provided a 3- to 4-fold increase in energy density than lead-acid batteries. The Ni-MH batteries have enabled the emergence of hybrid automobiles that use electric motors to supplement or provide traction with internal combustion engine (ICE) generators that power the motors or charge batteries. Plug-in hybrids use batteries that can be charged from the electricity grid or by on-board generators. Lithium-based batteries contain twice the amount of energy density as Ni-MH batteries, and are now being upscaled for use in plug-in hybrids. Canada has many assets that favour the development of electric vehicle technology as it has a high degree of urbanization, and a widely diversified electric supply. Canada is also a major player in EV technology, and a world leader in renewable electricity generation. However, considerable investment and leadership is needed in order to foster EV technology in Canada. It was concluded that an EV industry can be developed by facilitating collaboration among organizations currently promoting sustainable transportation, identifying potential centres of engineering and technological excellence, and defining markets relevant to a Canadian EV industry. 32 refs., 6 tabs., 4 figs
[en] This report summarizes key findings in two national plug-in electric vehicle charging infrastructure demonstrations: The EV Project and ChargePoint America. It will be published to the INL/AVTA website for the general public.
[en] Much interest has been aroused by fuel cell usage in motor vehicles, since this technology seems to overcome the conventional limits by other kinds of drive, i.e. the high environmental impact of internal-combustion engines and the drawbacks of electric battery vehicles in terms of maximum operating range and battery recharge time. After 2010 its costs are expected to fall in competitive levels with internal-combustion engines
[it]Le applicazioni delle celle a combustibile nei trasporti stanno incontrando molto interesse. Questa tecnologia sembra infatti superare i limiti tradizionali di altri tipi di azionamento: l'elevato impatto ambientale dei motori a combustione interna e le difficolta' del veicolo elettrico a batteria in termini di autonomia e tempo di ricarico. I costi sono previsti scendere a livelli competitivi con quelli dei motori a combustione interna dopo il 2010
[en] With a focus on the interaction between long-term climate targets and personal transport we review the electrification of light duty vehicles (LDVs) within a model that utilizes a learning-by-researching structure. By modeling the demand of vehicles, the use of fuels and emissions implied, the model solves for the optimum RD and D investments that decrease the cost of hybrid, plug-in hybrid and electric vehicles. A range of technology and climate policy scenarios provide long term projections of vehicle use that highlight the potential synergies between innovation in the transportation sector and the energy sector. We find that even when the capital cost of electric drive vehicles (EDVs) remains higher than that of traditional combustion engine alternatives, EDVs are likely to play a key role in the decarbonisation implied by stringent climate policy. Limited innovation in batteries results in notable increases in policy costs consistent with a two degree climate policy target. - Highlights: • Significant increase in vehicles across regions in the medium to long term future. • Climate policy costs are sensitive to a lack of electric drive vehicles (EDVs). • Achieving 450ppm with no change in battery costs has a policy cost that is 2.86 percentage points higher than the base 450ppm scenario. • Climate policy hastens the introduction of electrified vehicles, however EDVs do not become the dominant vehicle of choice before the middle of the century
[en] A device that can be fitted on a robotized vehicle for the up- or down-over-passing of obstacles such as stairs or kerbs, is presented: a supporting bar is fixed to the vehicle structure and rotates independently from the wheels of the vehicle, thus taking its bearing on the step of the kerb or stairs. Application to industrial robotized vehicles or wheel-chairs for the disables. 10 fig
[en] A large scale deployment of electric vehicles (EVs) is likely to contribute to a more sustainable transport system. However, charging EVs will increase the load on the electricity network. The maximum load may be minimized by coordinating the timing of charging activities, in order to spread electricity demand more equally over the course of a day. In this study, based on a stated-choice experiment, the effects of two different temporal price differentiation strategies on stated charging time are investigated, including socio-demographic, behavioural and socio-psychological variables. In a situation without charging time coordination, a peak in charging events is likely to occur during the early evening. Temporal price differentiation has a significant influence on charging time and in particular the level of price differentiation matters. The likelihood to change charging time differs and different alternative time slots are chosen when comparing high to low levels of price differentiation. People that have more knowledge about EVs have a higher chance to change their charging time, whereas people that have the tendency to plan their trips long time beforehand are less likely to adjust their charging time in the scenarios with temporal price differentiation. - Highlights: • Preferred charging time of electric vehicles is in the early evening. • Temporal price differentiation significantly influences charging time decisions. • Different levels of price differentiation stimulate different behavioural responses.
[en] Energy-harvesting shock absorbers (EHSAs) have been introduced in the last decade as a viable technology for improving the performance and durability of electric and/or hybrid vehicles. However, in order to gauge the potential that can be obtained from this technology in different environments, the computational models that are used should behave as close to reality as possible. One of the limiting factors in EHSAs, in terms of recoverable energy, is frictional losses between its moving parts. Depending on the friction losses, the dynamics and efficiency of the system will vary. This paper presents a method of identifying the friction parameters in a ball-screw energy-harvesting shock absorber (BS-EHSA) system for subsequent computational simulation. In addition, it shows qualitative and quantitative results of how these friction parameters could affect the comfort and adhesion of the vehicle, as well as the generated power and energy efficiency of the BS-EHSA.