World Electr. Veh. J., Volume 5, Issue 3 (September 2012) – 22 articles , Pages 629-824

Achieving greenhouse gas emissions reduction goals from the transportation sector will be a monumental challenge. Various alternative vehicle technologies such as plug-in hybrids, battery and fuel cell electric vehicles offer the promise of sharply reducing end use emissions. However, when considering the full fuel cycle, it is clear that a dramatically cleaner electricity grid will also be necessary if we ever hope to meet ambitious long-term reduction goals. To demonstrate the importance of achieving this dramatically cleaner grid, our analysis implements Argonne National Laboratory’s GREET model and the latest Annual Energy Outlook data to evaluate the relative merit of various alternative vehicles on a well-to-wheel basis while taking into account projections for the evolution of the U.S. electricity supply. Fortunately, significant progress is now underway to transform the electricity sector. The emergence of substantial supplies of shale gas, at low cost and substantial abundance, has dramatically reshaped the energy landscape. There are multiple pathways for this abundant supply of natural gas to help reduce the transportation sector emissions footprint, whether through greater utilization in highly efficient natural gas combined-cycle electricity generators, direct use in compressed natural gas vehicles, or steam reformation to provide hydrogen for fuel cell vehicles. Greater reliance on high efficiency natural gas combined cycle generators, combined with the steady expansion of renewable generation and energy efficiency, is providing a critical alternative to continued reliance on dirty, legacy generators. This emerging new clean power paradigm can multiply the benefits of more rapid growth in electric drive vehicles. Full article

Electric vehicles have a clear benefit over conventional vehicles when it comes to the impact on climate change. Underlying paper describes how fast (or slow) the uptake of electric vehicles can change the overall performance of an entire fleet on climate change. The benefit of a large share of electric vehicles in a fleet is compared to a future fleet with energy efficient conventional vehicles (petrol and diesel). The study area is the car fleet of Brussels, Belgium. The time horizon is 2020. It is investigated how big the climate benefits can be of a potential uptake of electric vehicles in a fleet. Two different vehicle fleets of the Brussels Capital Region (BCR) are compared with a Life Cycle Assessment (LCA), consisting of a ‘business as usual’ and an ‘EV uptake’ set of vehicles. Future electricity mixes, with more renewable energy, are taken into account. It is concluded that a moderate uptake of electric vehicles (as described in the paper) leads to a yearly emission reduction of 10 kton CO₂ in 2020 for the Brussels Fleet compared to a reference scenario. This means that in 2020 it is possible to have a fleet in Brussels consisting of 1,8% BEV’s 1,6% PHEV’s that reduces 1,9% (or 10 kton CO₂) of the yearly CO₂ emissions when compared to a ‘Business as usual’ scenario. Full article

A population of drivers was simulated using a microsimulation model. Consistent with the 2001 National Household Travel Survey (NHTS), a wide range of daily driving distance was observed. This heterogeneity implies that some drivers will realize greater fuel savings from driving a plug-in hybrid electric vehicle (PHEV) than others, therefore, consumers who choose to purchase PHEVs may tend to be those who drive farther than average. The model was used to examine the effects of this difference in driving by estimating fuel use, electricity demand and GHG emissions by two populations, one assigned PHEVs at random to some fraction of drivers, and the other assigned PHEVs to drivers who realized operating cost savings at least as great as the amortized incremental cost of the PHEV relative to a comparable conventional vehicle. These two populations showed different distributions of daily driving distance, with the population of PHEV drivers selected on the basis of operating cost savings driving 40% farther per day on average than average drivers. This difference indicates the possible range of driving patterns of future PHEV drivers, which should be taken into account when estimating fuel savings and GHG reductions from PHEVs. For example, if 20% of U.S. vehicles were PHEVs, we find a potential reduction of fuel use of 0.17 gal per day per vehicle if PHEVs substitute randomly for conventional vehicles, whereas the fuel savings is as large as 0.26 gal per day per vehicle if PHEVs are substituted according to operating cost savings. Similar differences in GHG emissions were estimated as well. The effects of electricity demand management on charging PHEVs was examined for these two populations. It was found for both that only a small fraction of PHEVs were impacted by interruptible electricity service (no charging permitted during peak hours). Most PHEV drivers were able to charge sufficiently during off-peak hours and saw little change in operating costs. This implies that interruptible electricity service may impact operating costs of only a small fraction of PHEV drivers. Full article

This is a Report on the first phase of a demonstration of Neighborhood Electric Vehicles (NEVs) in the South Bay Subregion of Los Angeles County. The project is sponsored by the South Bay Cities Council of Governments (SBCCOG) and funded by the South Coast Air Quality Management District (AQMD). Active use of the first demonstration phase began May 1, 2010 and ran for 18 months ending October 31, 2011. This Report, based on the 18 months of data collection and analysis, aims to identify the positive role NEVs can play in addressing the following issues:
• Reducing green house gas emissions, criteria air pollutants, and consumption of fossil fuels by passenger vehicles and light trucks.
• Informing government plans and policies currently being formulated, including the 2012 Regional Transportation Plan, California Energy Commission’s initiative for electric vehicle readiness, and the California Air Resources Board AB 118 vehicle voucher program.
• Implementing the Sustainable South Bay Strategy with its mobility initiative based on transitioning the gasoline fueled passenger vehicle fleet to some form of electric vehicle. Because this study is extremely data rich, a very detailed and scientific analysis has been completed for a somewhat small sample size of 29 participating households. From these findings it is clear that significant GHG and criteria air pollutant reductions could be achieved from wide spread use of NEVs for suburban residential driving. This research has also identified numerous market barriers that prevent wide spread adoption of NEVs as well as strategies to overcome market barriers such as production quality, speed limitations, and NEV prices. Full article

The reduction of CO₂ emission by the transport sector is necessary to be realized the low carbon society. In the near future, further CO₂ emission reduction is expected by the diffusion of PHEV. The aim of this study was to evaluate the potential of PHEV to reduce CO₂ emission based on real-world driving data (probe car data) and simulation. The probe car data of 35 conventional HEVs from April to August in 2011 were analyzed. The type of simulated PHEV system was all electric range, which operated only by battery power as long as available battery capacity was remaining (EV mode) , and then operated like conventional HEV after battery was depleted (HEV mode). Charging frequency was once a day at home after midnight as a realistic scenario. The results showed that the travel distance of 43% was converted to EV mode, and the gasoline consumption was reduced by 44%. The CO2 emission was totally reduced by 17% considering electric power consumption. CO₂ emissions of each vehicle were reduced by 1-44%. CO2 reduction amount of each vehicle varied widely reflecting their each own ways of car use and operating conditions. It is indicated that the diffusion of PHEV is a realistic and efficient measure to reduce CO₂ emissions in consideration of actual car use and operating conditions. Furthermore, low carbon power supply as well as diffusion of PHEV is more effective to CO₂ reduction. Full article

This study analyses the integration of electric vehicles (EV) into the German power grid including different demand side management (DSM) approaches from a technical, economical and user perspective. For this an overview of the future German electricity market with the focus on EV integration is given. It is shown that for conservative EV penetration rates the effect on the electricity generation is marginal while the shortage in the regional and local electricity grid could be already significant. DSM in combination with smart grids can help to tackle this issue by controlled charging of EVs. One simple concept is to postpone the charging process by offering incentives to vehicle users e. g. with dynamic electricity tariffs. The common Time-of-Use (TOU) tariff defines in advance a dynamic tariff scheme according to the load forecast for the following days. This allows to release the local electricity grid and to increase the share of renewable energies: In times of high electricity generation by renewable energies and low electricity demand the price is low and vice versa. The impact of these dynamic tariffs on the charging process of EVs is shown in a techno-economic analysis for an exemplary urban high voltage grid by an optimising energy model. These strong impacts are however somewhat reduced by the acceptance and the low profits for the single user. At least for the users in a German field trial, environmental aspects played a major role in influencing the charging behaviour – this gives still hope for the future. Full article

This paper presents an analytic solution to find the optimal amount of lightweighting in a battery electric vehicle (BEV). The additional cost of lightweighting is traded off against the cost savings due to the smaller battery and motor required at constant performance and range. Current technology cost estimates indicate that for a medium sized BEV, optimal glider mass reduction is on the order of 450 kg in 2012 leading to estimated manufacturing cost reductions of 4.9%. Declining powertrain costs are expected to reduce the importance of lightweighting in minimizing BEV cost in the future, and rising electricity costs to increase the gap between the optimal solutions based on minimizing manufacturing versus total costs. The results are strongly dependent on the future development of lightweighting, battery, and electricity costs. The sensitivity of the optimal mass reduction to these critical parameters has been evaluated, and is shown to increase over time. Full article

Many electric utilities have begun piloting Electric Vehicle (EV) charging stations with a number of manufacturers, including Siemens. As a result of working with these EV charging station manufacturers, utilities have developed a good understanding of prevailing technology. While utilities consider options like selling or recommending preferred EV charging stations to new EV owners in their service territory, a trend has emerged where new EV owners purchase charging station technology without notifying the utility based on recommendations from their EV dealers. It is important for the utilities to be aware of customers in their service territories that are installing EV charging stations in their homes and businesses in order to plan for the required distribution network upgrades to serve these stations. Siemens has worked with a number of utilities to discuss their business requirements for a software solution envisioned to manage the installation and use of EV charging stations in their networks. This paper reviews both the problem these utilities are trying to solve together with their functional and integration requirements for a comprehensive EV charging station management system which can support utility programs including critical peak pricing programs, demand response, outage management, etc. Full article

In this paper we present a novel composite methodology for obtaining spatial projections of the impacts and opportunities arising from the integration of plug-in electric vehicles with future smart electricity grids. We link models of future plug-in electric vehicle uptake, travel by household members, household electricity demand, and recharge of electric vehicles. The analysis is disaggregated in each case to a mesh block or local government area level; vehicle usage and household energy demand fluctuate on a hourly, daily and seasonal basis, subject also to the longer-term trends projected for uptake of the new technology. A similarly fine grain is applied with respect to socio-economic variables. The uptake model combines features of choice modelling, multi-criteria analysis and technology diffusion theory; in this case it was applied to four competing technologies (BEV, PHEV, HEV, ICE), and calibration revealed seven major determinants of uptake: performance, annual costs, purchase cost, household income, driving distance, demographic suitability, and risk or inconvenience. The travel model projects likely patterns of vehicle usage and travel duration based on existing patterns of private vehicle usage. The household demand model includes detailed representation of housing type and usage of electrical appliances. The charge-discharge model embodies plausible algorithms for managing household electricity usage in conjunction with electric vehicle batteries. In the paper we describe the various models and report projected impacts of electric vehicles on peak electrical grid loads for the Australian state of Victoria. The impacts are presented on a spatial basis, to the level of individual mesh blocks and network feeders, under a range of energy management scenarios. Full article

Plug-in electric vehicles (PEV) are considered to be a potentially sustainable alternative to conventional vehicles for private transport and a way of balancing intermittent generation from renewable energy sources (RES). Using RES for electric mobility would be superior to all available fossil generation alternatives in terms of emissions and efficient energy conversion. To quantify the marginal energy from RES used, two charging strategies last trip charging and optimized demand-side management (DSM) with dynamic pricing are investigated for a German long-term high RES power mix scenario. The results for both charging cases indicate that the power demand for PEVs will not be met by RES. For last trip charging 1.40% comes from RES. In terms of DSM this share increases to 7.38% but results in higher overall CO2 emissions because for Germany coal provides the lowest cost fossil power. Hence DSM charging reduces peak load and helps to balance RES generation but is contrary to the original idea of clean transportation because of higher marginal emissions caused by the utilisation of coal. To account for contractual arrangements allowing consumers to directly purchase RES electricity, a second scenario with additional installed RES capacity is analysed. Because of the high RES share of over 50 % a complete usage of the RES is not possible and a small fraction of power must still be provided by dispatchable power plants. For the second scenario, DSM charging also allows for an increased use of RES compared to last trip charging (99 % versus 90% RES). In addition, total marginal CO2 emissions are lower and DSM helps to balance the ramping of RES. Therefore, it is concluded that for Germany the installation of additional RES and DSM charging would guarantee clean transportation using electric vehicles. Full article

Mahindra Reva began a program of developing telematics capabilities in its electric vehicles around 4 years ago. The primary motivation for considering this technology was to enable remote diagnostics capabilities for our cars that are spread over 24 countries. This paper describes the evolution of telematics enabled capabilities at Mahindra Reva. This paper is divided into four broad sections: (1) we first present a technical overview of the telematics system; (2) we then briefly describe the categories of beneficiaries of telematics and the features and benefits to each category; (3) we then present the results from a survey of our existing battery electric vehicle owners on their perceived utility for such features; (4) based on these we develop a simple cost-benefit analysis to enable investment decisions in this technology and understand the payoffs from the investment. Full article

Siemens, along with its partner BMW, recently concluded a feasibility study that focused on inductive charging of passenger electric vehicles. The objective of the study was to verify that automatic wireless charging could be accomplished with a comparable level of efficiency to today’s conductive solutions and without impact to human or vehicle safety. In its first phase, the study began with testing of a non-vehicle integrated solution. After verification of KPIs, the second phase of the study proceeded to integrate the technology into two BMW ActiveE electric vehicles. The study specifically measured power transfer efficiency with varying levels of coil to coil air gaps and misalignments between the road side and in-car coils while observing the most influential factors. Key findings of the study were that two areas merited further focus - the design of the coil system and the necessity for air gap observation. It is clear that as the automotive OEM community continues to seek inductive solutions that are smaller, lighter, more efficient, and less costly, these areas along with positioning guidance technology will be critical topics of further research. Siemens is using the results of the study to enhance their 2^nd generation prototype which seeks to significantly reduce the size and weight of the inductive coils while adding in compliances and certifications to in-car safety and quality standards. Full article

This paper describes the processes used and the choices made while developing a procedure to evaluate Electric Vehicle Supply Equipment (EVSE) and Plug-in Electric Vehicle (PEV) chargers and provides some results of the testing process. The procedure defines the battery charging system (i.e., the battery charger, EVSE, battery storage system, auxiliary loads, and vehicle). Each test element is evaluated in terms of function, reliability, safety, quality, cost, efficiency and power quality. The development of a charging system evaluation procedure comes from Southern California Edison’s (SCE) responsibility to ensure safe and reliable function and to minimize system impact. Up to one million PEVs have been projected to be operating in SCE’s service area by 2020. SCE must not only serve these PEVs, but must ensure that they do not have a negative impact on the utility grid. Therefore it is critical that SCE understand the impact of those battery charging systems. SCE also supports the creation of standards to limit wasted energy and negative power quality impacts that these battery charging systems may create. SCE is also using the test procedure to evaluate EVSEs and PEV charging systems for implementation in SCE’s fleet. The results of this procedure are used to give fleet managers the information needed to acquire the most effective and efficient PEV charging equipment. The results will also tell a fleet manager or PEV owner what EVSE would work best with their selected vehicle or vice versa. The procedure provides for the discovery of PEV and EVSE individual and compatibility issues before the PEV is deployed. The final result ensures optimum performance of the PEV system. Through this process, SCE has been able to work with manufacturers of PEVs and EVSEs in order to improve the functionality, robustness, and interoperability of the products. Full article

How did Norway get a highly developed database for charging stations, capable of real-time updates on availability, ready and free to be adopted by any country? A co-operation between Transnova, a governmental entity, and the association of EV-users to develop an open database which allows everyone to build services upon standardized data. Full article

This paper describes “smart charging” systems for plug-in hybrid electric vehicles (PHEVs). The principal design feature is that the system uses gathered information to adaptively control PHEV charging, and does so in a way that allows customer PHEVs to still be charged at a preferred rate (cost). This paper reviews the drivers for smart charging, including electric grid readiness for large adoption rates of PHEVs, and considers national, regional and local distribution level issues. At the distribution level, the effect of increased PHEV charging loads on transformers is considered. The current state of standardization is reviewed with emphasis on communication messages and use cases that reflect smart charging attributes. Centralized system approaches are described, such as integrating electric vehicle supply equipment (EVSE), i.e. chargers, into Advanced Metering Infrastructure (AMI) networks, and treating EVSEs as controllable loads for Demand Response programs. Metering and monitoring the transformers that feed EVSEs can drive a control scheme that is either centralized or distributed. Alternatives to AMI-integration for centralized networks are also reviewed, including commercially available systems. Additionally, smart charging is considered from the billing perspective, where system approaches are described that allow for identification and association between connected PHEVs, EVSEs, premise meters and other smart devices. Full article

In this work we address the efficient operation of public charging stations. Matching energy supply and demand requires an interdisciplinary understanding of both the mobility of electric vehicle (EV) users and the load balancing mechanisms. As a result of existing mobility studies, we propose in this work a routing service for searching and reserving public charging spots in the neighborhood of a given destination. When comparing the search results for direct drive with those for a multimodal route (using driving, walking and public transport) in an urban environment, we obtain for the latter significantly more charging options in particular at low e-mobility penetration levels, at a cost of slightly longer trip duration. Further contributions address the schedule optimization, that, due to the proposed distributed architecture, can be performed independently at each public charging station. We formulate an integer program for the controlled charging and compare results obtained both with the exact and with a greedy heuristic method. Full article

Vehicles driven on alternative fuels, such as electric vehicles (EVs), are becoming more common while awareness of a diminishing oil supply, oil prices and environmental pollution are increasing. Despite technical breakthroughs, the low energy density in the battery is a problem that limits long distance travel, especially for heavy-duty vehicles (HDV). The low energy density combined with the high cost and the uncertain predictable lifetime of the battery could be estimated to hamper the expansion of the long distance EVs. Electrified highways connecting cities could be one solution to reduce the battery and fuel dependency by supplying electricity continuously to the vehicles. Different technical solutions of electric roads, both conductive and inductive, have been proven functional but are today mainly used in the tram and train industry. Despite the inductive system’s major benefit of not relying on a physical contact, an inductive system is not necessarily the best option due to high costs and questionable efficiency. This said, also a conductive system intended for highway transport, despite the mature technology used, is far from problem free. This paper presents the new concept Poly segment monorail (PSM), intended to reduce the drawbacks of the general conductive system for highways. PSM utilizes segments alternating each other at road level, in contrast to traditionally being parallel and sometimes partially buried. With the new design and segments that are galvanically insulated, reduced losses and increase safety could be achieved. The paper also highlights the complexity for the new technology, involving several stakeholder markets, to achieve an international standard, which could be estimated a requirement for such a system to be beneficial and reasonable. Full article

ECOtality was awarded a grant from the U.S. Department of Energy to lead a large-scale electric vehicle charging infrastructure demonstration, called The EV Project. ECOtality has partnered with Nissan North America, General Motors, the Idaho National Laboratory, and others to deploy and collect data from over 5,000 Nissan LEAFs^TM and Chevrolet Volts and over 10,000 charging systems in 18 regions across the United States. This paper summarizes usage of residential charging units in The EV Project, based on data collected through the end of 2011. This information is provided to help analysts assess the impact on the electric grid of early adopter charging of grid-connected electric drive vehicles. A method of data aggregation was developed to summarize charging unit usage by the means of two metrics: charging availability and charging demand. Charging availability is plotted to show the percentage of charging units connected to a vehicle over time. Charging demand is plotted to show charging demand on the electric gird over time. Charging availability for residential charging units is similar in each EV Project region. It is low during the day, steadily increases in evening, and remains high at night. Charging demand, however, varies by region. Two EV Project regions were examined to identify regional differences. In Nashville, where EV Project participants do not have time-of-use electricity rates, demand increases each evening as charging availability increases, starting at about 16:00. Demand peaks in the 20:00 hour on weekdays. In San Francisco, where the majority of EV Project participants have the option of choosing a time-of-use rate plan from their electric utility, demand spikes at 00:00. This coincides with the beginning of the off-peak electricity rate period. Demand peaks at 01:00. Full article

Using the 2009 National Household Transportation Survey (NHTS), an analysis of opportunity charging potential during daytime, for the time interval when a car or SUV is parked for the longest duration, is presented here. We focus on charging at 3.3 kW or less, either using the charger at the dwelling unit a second time per day (a one charger solution), or using a second charge point at work. Our earlier research with the 2009 NHTS indicates that nearly 60% of vehicles within this sample were driven to work, or returned to home between 6:00 AM and 6:00 PM. In this analysis we consider the potential for daytime charging before summertime afternoon utility load peaks, anticipating that Public Utility Commissions (PUCs) supporting smart grid pricing strategies may impose much higher electricity costs at these times. We consider kW ratings of typical opportunity chargers versus overnight chargers. We consider the plug-in hybrid with 28 km of urban electric range (PHEV28), the extended range electric vehicle with 56 km of universal all-electric operation capability (EREV56) and the battery electric vehicle with 117 km of electric range (BEV117). Electricity demand and gasoline fueled miles reduction is examined for the average circumstance in two daily distance brackets (48-80 km, 80-160 km) and for two charging behaviors – (1) overnight and (2) both overnight and during the longest duration parking event of daytime hours, from 6 am to 6 pm. Full article

A contactless power transfer system for charging electric vehicles requires a high efficiency, a large air gap, and a good tolerance to lateral misalignment and needs to be compact and lightweight. A double-sided winding 10 kW transformer based on a 1.5 kW H-shaped core transformer was developed for a rapid charger. Even though the transformer capacity was increased, the dimensions of the 10 kW transformer were almost the same as those of the 1.5 kW transformer. In this paper, the design concept for this 10 kW transformer and the results of experimental are described. The transformer was found to exhibit more than 94% efficiency with a mechanical gap of 70mm. Even for gap change and position change, an efficiency of over 92% was maintained. In a contactless power transfer system with a series resonant capacitor, the primary terminal voltage increases with increasing power. This overvoltage may lead to the problem of breakdown voltage of capacitor and the breakdown of winding insulation. To prevent such an overvoltage occurring, it is suggested that the primary winding and the series capacitor are split into two pieces or more respectively, and the split windings and capacitors are alternately connected in a series. Electric vehicles using a contactless power transformer for rapid charging would also uses normal charging. Therefore, the 10 kW transformer was designed to be compatible with the 1.5 kW transformer. Consequently, electric vehicles equipped with the 10 kW transformer can charge even using a 1.5 kW ground transformer, without decrease efficiency. Full article

A PHEV demonstration project gave 80 consumers within the Northern California counties of Sacramento, Yolo and San Joaquin the opportunity to drive a PHEV-conversion for at least one month each in lieu of one of their existing vehicles. Households decided for themselves when, where, and how much to charge the PHEV, if at all. Out of the 80 households, 25 were characterized as plausible future PHEV owners who also commuted to a workplace. Each of the PHEV-conversions was equipped with loggers which recorded all travel and charging data. To estimate the potential implications of added workplace charging infrastructure across a group of commuting households, each household’s vehicle usage is simulated with six hypothetical PHEVs, the design characteristics of which are outlined in Table 2 of this paper. Combining each household’s usage data with the hypothetical designs allows their PHEV-conversion experience to be generalized beyond the specific PHEV-conversion to plausible future PHEV designs. Since most households did not have access to charging infrastructure at work, charging events are simulated for each household every time they arrive at their workplace. Comparison between the recorded behavior and the simulated workplace charging case allows for an exploration of the potential impacts of workplace charging on the individual and fleet utility factor, workplace charging infrastructure requirements, and grid load. Workplace charging increases the total fleet average utility factor, however, the benefit varies considerably by household and vehicle charge depleting range. Based on simulation results, up to 75% of commuters would be able to use 1.44 kW charging without experiencing a decrease in electric miles driven, and workplace charging creates a new peak vehicle charging load on the grid in the morning, in the range of 0.8 to 1.4 kW per PHEV. Full article

Battery electric vehicles combined with renewable energies have a huge potential to reduce CO2- emissions, especially in the field of motorized individual transport. However, a future change from combustion engines to electric drives leads to new problems and challenges. From the perspective of energy engineering, among others, the following questions arise:
• Where should be charging infrastructure for electric vehicles created?
• Which connection power should be provided?
• How big is the additional grid load?
• What must be done to prevent overloading?
These questions are dealt with in the Austrian research projects “Smart Electric Mobility” and “V2G - Strategies” with national partners from academia and industry (funded by the Austrian Climate and Energy Fund, programme “New Energy 2020”). The methods and selected results are presented in this paper.
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