World Electr. Veh. J., Volume 5, Issue 4 (December 2012) – 30 articles , Pages 825-1130

Rose-Hulman is competing in EcoCAR2, a three year competition where teams design, build, and test a hybridvehicle architecture. Teams are required to generate vehicle models that will be used throughout the life of the competition. The model is used to choose a hybrid architecture, design a robust control scheme, implement fault mitigation strategies, and optimize vehicle performance. Modelling techniques include Model-in-the- Loop, Software-in-the-Loop, and Hardware-in-the-Loop. This paper will discuss the techniques developed to build a model that can be actively used for the life of the three year competition and maintained across the MIL, SIL, and HIL modelling levels. Full article

Standard cycles provide an easy way to evaluate the energy consumption of vehicles, but it is the energy consumption that occurs on real-world trips that really matters to the driver and, to a larger extent, society. This study shows how digital maps and vehicle simulation tools can be used to estimate energy consumption on a real-world trip. The user (1) selects a trip in the mapping service ADAS-RP (Advanced Driver Assistance Systems Research Platform), (2) defines a vehicle model in the vehicle powertrain simulation tool Autonomie, and (3) runs and analyzes the simulation in that same tool. For each section of the trip, ADAS-RP provides various information that can include speed limits, historic data on traffic pattern speeds, the slopes of the routes, and the positions of stop signs and traffic lights. The first stage of processing this information is to schedule the stops and to create an intermediate speed target that takes those stops into account. The final driver demand speed includes transitions – accelerations and decelerations – between sections with different intermediate speed targets, or around stops. The ADAS-RP/Autonomie process is then used to compute the energy consumption of a hybrid electric vehicle and a conventional vehicle on 10 trips defined across the United States and Germany. The hybrid vehicle is more fuel efficient, especially on congested routes and routes with downhill slopes, the effect of which is analyzed in further detail. Full article

Most studies on power train design rely on deterministic driving cycles to define the vehicles longitudinal speed. Especially simulations on hybrid propulsion systems use driving cycles to define the speed sequence of the vehicle and backwards calculate the power for traction. Disadvantages of this deterministic approach are the limited value of one driving cycle to represent real-life conditions and the possibility of ’cycle beating’ in optimizations. Observations suggest that the distribution of the power for traction is more easily characterized than the distribution of the speed, as it tends to a bell-shaped curve. This study proposes to approximate the bell-shaped distribution with a normal (Gaussian) distribution when considering sizing hybrid electric propulsion system with a fixed gear ratio. This proposal is motivated from simulations, chassis dynamometer experiments and real-world data. In addition, mean and variance of the normal distribution are linked to the parameters of the vehicle and the properties of the driving cycle under consideration. The resulting characterization of the power for traction with a normal distribution provides a more generic specification for the vehicles power demand than deterministic driving cycles. This simplifies decisions on the sizing power train components and the engineering of the energy management system, as results not only hold for one driving cycle but for all driving conditions that match the same statistical distribution of the power for traction. Full article

This work describes a method developed to simplify and reduce the cost of the standardized testing required to measure the energy consumption of electric motorcycles before they are sold on the Swiss market. The robust algorithms for estimating four characteristic parameters of electric two-wheelers are based on a linear dynamics model that is considered to be as simple as possible yet as complex as necessary to characterize the vehicles. The model equations are investigated analytically for their ability to find unique solutions, and it is shown that multiple solutions may exist. The algorithms are tested for their ability to handle various data frequencies, levels of noise, and initial guesses. Ultimately it is found that these methods effectively enable the use of simulation models trained on real-world driving to run mandated standard test cycles in place of expensive dynamometer testing to estimate on-road energy use. Full article

The range of Electric Vehicles is highly influenced by the electric power consumed by auxiliaries, a huge part of this power being used for cabin heat-up and cool-down operations in order to ensure an acceptable level of thermal comfort for the passengers. Driving range decreases with low temperatures in particular because cabin heating system requires an important amount of electric power. Range also decreases with high ambient temperatures because of the air conditioning system with electrically-driven compressor. At the same time, batteries and electric motors operates at their maximal efficiency in a certain range of temperature. The reduced EV driving range under real life operating cycles, which can be a barrier against market penetration, is an issue for further development in the future towards sophisticated cabin heating and cooling systems, as well as battery warmer. The aim of this paper is to highlight the benefits of a system simulation approach, based on LMS Imagine.Lab AMESim, in order to estimate the impact of various technologies of cabin heating and cooling on both the cabin temperature and the driving range. In this paper, a battery electric vehicle including a cabin heating with PTC device and a R134a refrigerant loop is simulated under various ambient temperatures on a given driving cycle with the same required cabin temperature target. Simulation outputs include the cabin temperature evolution, the battery state of charge and as a consequence the driving range. Full article

Recently, the global automobile market is rapidly changing in the paradigm to next-generation automobiles with high-efficiency and eco-friendliness due to rising oil prices and strengthened environment regulations. Accordingly, the automobile vendors around the world are competing in development of hybrid vehicles, plug-in hybrid vehicles, fuel cell vehicles, electric vehicles and such various vehicles. Before developing the components that such vehicles are comprised of, however, it is very important to predict/assess the performance of the components when used to construct such vehicles using the components to be developed. Yet, it is very difficult to design considering the operational characteristics at the vehicle level during the design stage of the components, or conduct testing/evaluation considering vehicle characteristics. To resolve such issues, this study involved using MATLAB/Simulink, one of the simulation programs widely used by system engineers to construct performance evaluation environment for eco-friendly vehicles, and using 3D rendering tool of Multigen Creator to construct virtual driving environment so as to construct the performance evaluation environment for components of the vehicles. The constructed virtual driving simulator could be utilized for designing core components for Eco-friendly Vehicles, and verifying the performance per vehicle unit. Full article

Vehicle to grid communication standards are critical to the charge management and interoperability among plug-in electric vehicles (PEV), charging stations and utility providers. The Society of Automobile Engineers (SAE), International Organization for Standardization (ISO), International Electrotechnical Commission (IEC) and the ZigBee Alliance are developing requirements for communication messages and protocols. While interoperability standards development has been in progress for more than two years, no definitive guidelines are available for the automobile manufacturers, charging station manufacturers or utility backhaul network systems. At present, there is a wide range of proprietary communication options developed and supported in industry. Recent work by the Electric Power Research Institute (EPRI), in collaboration with SAE and automobile manufacturers, has identified performance requirements and developed a test plan based on possible communication pathways using power line communication (PLC). Though the communication pathways and power line communication technology options are identified, much work needs to be done in developing application software and testing of communication modules before these can be deployed in production vehicles. This paper presents a roadmap and results from testing power line communication modules developed to meet the requirements of SAE J2847/1 standard. Full article

Besides cost issue, the charging infrastructures popularization and charging safety assurance are two major concerns for promoting electric vehicles (EVs). Several pilot-run programs, such as in the U.S., Europe, Japan, China, and Taiwan as well, enforce the safety compliance of EVs and infrastructures as an implementation policy. To be part of the players, it is essential to have the comprehensive understanding of the standard differences among IEC, SAE/UL, GB and JEVS. The way to compile the issued standards in different regions, however, is time consuming and may get limited helpful hints until tried and tested. Based on above-mentioned standards, this study summarized an overview in aspects of construction, function, performance and safety for charging equipments. To facilitate as a competent safety design, key requirements of electrical safety were presented. These crucial design rules included functional requirements, constructional requirements, personal protection against electric shock, insulation coordination, electromagnetic compatibility and charging control. The rationale and compliance requirements were highlighted to assist as design guidelines. In addition, learning from the past is always a good approach to build confidence to comply with the safety requirements. Based on the standards—follow most IEC and some SAE/UL—for pilot-run project in Taiwan, a case study of an AC charging stand provided the safety faults encountered and solutions in designing a new product that can meet safety requirements effectively. With these design guidelines and the case study, this paper provided a solid basis of safety design for electric vehicle charging equipments. Full article

The IEA Implementing Agreement (IA) “Hybrid and Electric Vehicle Technologies and Programmes” is an international working group of actual 17 governments interested in hybrid-, fuel cell- and electric vehicles. It works as a platform for information exchange about national programmes and activities and for collaboration on various topics. This collaboration platform is an efficient way to share information, to avoid misguided activities and to start joint efforts. The collaboration saves money and speeds up the development of the national programmes. This speeds up the market introduction of all kind of “Hybrid- and electric vehicles”. This presentation describes the results of the working groups. The planned new working groups will be explained. Full article

In 2011 the Flemish government launched the Living Labs Electric Vehicles, consisting of 5 different platforms each differing in technology, scope, size and use patterns. For the build-up of these platforms, the Flemish government relies on private companies, local authorities and research institutes. These platforms serve as an environment in which platform members as well as other partners can carry out experimental research related to the roll-out of electric vehicles (EVs) and EV fleets. A total financial investment of ±30 million € was made, equally divided between the private sector and the government, and an introduction of 600 electric vehicles and 600 new electric charging points is aimed for. The addressed research topics within these living labs include the assessment of the driving range of the EVs, the assessment of the implemented drivetrain technologies and charging infrastructure, travel- and purchase behaviour, market potential analyses, the development of new business cases, the development of new services and products, total cost of ownership analyses, environmental impact analyses, and social acceptance. In addition, with respect to the charging infrastructure, standardization issues, interoperability of the charging systems, and billing and roaming procedures are studied. A wide variety of stakeholders related to electric mobility is involved in these living labs, ranging from knowledge centres, automotive manufacturers, electricity producers and distributors, service providers. public transport companies and local authorities, to fleet owners and end users. This paper gives an overview of the 5 launched platforms: EVA, iMOVE, Olympus, EV TecLab and Volt-Air. Full article

EVUE is a European funded exchange of experience project for 10 cities developing Electric Vehicle strategies. The initiative demonstrates the benefits of collaboration and shared learning for urban professional and policy makers learning how to integrate EVs at early market stages. It promotes fresh approaches to integrated planning and to delivering the potential of electric mobility in sustainable cites of tomorrow. Full article

In this study, we develop a model to provide a policy framework guiding the transition of transportation systems to alternative-fuel powered ones. The model is capable of obtaining good subsidy strategies by solving an optimization problem that maximizes social welfare. Model results suggest a large net gain to the society from a well-planned transition. Full article

Plug-in Electric Vehicles (PEVs) are ready for commercialization. Perhaps the biggest hurdle remaining to their widespread adoption and to achieving California’s smog and climate change emission reduction goals is consumer acceptance and purchase. To help educate consumers as well as other important stakeholders, the California Plug-in Electric Vehicle Collaborative (Collaborative) partnered with the California Air Resources Board (CARB) to develop a PEV Resource Center as part of the DriveClean.ca.gov web site. The PEV Resource Center is an unbiased source of information about PEVs to help a number of different audience groups in California understand more about electric drive technology and what is involved with purchasing a PEV. This great new resource allows consumers, local government officials, policymakers, fleet managers, Original Equipment Manufacturers (OEMs), utilities, dealers, and the media easily navigate to find the PEV information they are looking for. Full article

The need to cut carbon emissions from cars and small vans is becoming an increasingly important issue. In the UK, it is anticipated that the electric vehicle (EV) will play a key role in meeting the 80% emissions reduction target in the Climate Change Act 2008. Although there are no emissions at their point of use, the equivalent emissions from an electric vehicle are dependent on the electricity used to recharge the EV’s battery. This electricity is generated from coal (910gCO2/kWh), natural gas (400gCO2/kWh), nuclear (zero emissions) and renewables (zero emissions). The contribution of these power sources to the overall energy mix varies depending on the time of day; meaning that the average carbon content varies from an ‘off peak’ minimum of 366gCO2/kWh at 03:00am to an ‘on peak’ 466gCO2/kWh at 18:00pm. Therefore, depending on when an EV is recharged, the effective carbon content of the electricity stored in the battery varies. This study aims to quantify the carbon emissions and power demands of electric vehicles when in everyday use, by correlating the times of day when drivers recharge their cars with the carbon content of electricity at that time. Data was collected through the Switch EV trial in North East England, which see 44 electric vehicles employed in the region for three years. Analysis of the behaviour of these drivers over a six month period indicates that the average carbon content of the electricity transferred into an EV during recharging is 436gCO2/kWh. Changes in charging behaviour could lead to a 70gCO2/kWh reduction in emissions. Full article

In order to describe the trend of motor system development of electric vehicle and to figure out the factors that would affect the external drives and the internal resources, the thesis uses scenario analysis method to be the basic framework, adding modified Delphi method to clarify time transition into five categories: changeless, changeable, disappeared, uncertain states and newborn. More precisely, the five factors is used to construct “Scenario Analysis of Markov Modified Delphi Method”. The thesis focuses on motor system to do the Foresight analysis, using the transition concept of Markov Chain to clarify the key factors of uncertain states into motor system: brushless DC (BLDC) motor, surface permanent magnet synchronous motor and Switched Reluctance In-Wheel Motor. Moreover, the changeless concept of Markov Chain is used to be background, adding the key factors of changeable and uncertain states to clarify seven kinds of scenario portfolio: basic scenario, scenario assumption I, scenario assumption II, future scenario, breakthrough scenario I, breakthrough scenario II and challenge scenario. It could make the government, industries and related departments realize the development trend of key components about electric vehicle by the scenario descriptions. It can increase their willingness to invest in the related researches to achieve future image, also shape the usable engineering technique and integrated system concepts of electric vehicles in 2020 for public. Full article

The National Alternative Fuels Training Consortium (NAFTC) is a pioneer and national leader in developing, managing, and promoting programs and activities that desire to cure America’s addiction to oil, lead to energy independence, and encourage the greater use of cleaner transportation. The NAFTC is the only nationwide alternative fuel vehicle and advanced technology vehicle training organization in the United States. The NAFTC is developing an Advanced Electric Drive Vehicle Education Program funded by the US Department of Energy. This program will help accelerate mass market introduction and education of advanced electric drive vehicles to help reduce the country’s dependence on foreign oil. The end result will be a cutting-edge nation-wide program for education, training, outreach, and public awareness for advanced electric drive vehicles, electric system components, and supporting electrical infrastructure. Curriculum development for this project include First Responder Safety Training, Automotive Technician Training, Career and Technical Training (High School Audience), and Infrastructure Training. Audiences for these courses include but not be limited to: mechanics/automotive technicians; automotive technology instructors and other community college instructors; career and technical education teachers; electrical infrastructure installation and repair technicians; first responders; fleet operators; safety, code and standards officials; utilities personnel; and others. This project will also encompass a robust outreach and education component consisting of a Advanced Electric Drive Vehicle Education Program website, toolkit, extensive marketing plan, vehicle simulation and training tool, and National AFV Day Odyssey. Full article

The Energy Technologies Institute has commissioned a portfolio of projects into plug-in vehicles. These projects have undertaken a detailed assessment of the business case for the mass-market deployment of plug-in vehicles in the UK and the required energy infrastructure. New research has been undertaken, together with analysis and modelling where appropriate to understand the interrelationships between government policy, consumer attitudes, automotive industry investment and energy industry investment. The effects of the wider macroeconomic environment have also been evaluated. These projects have conducted new research to develop a world-leading and comprehensive knowledgebase, based on an integrated system approach:
1. Detailed bottom-up projections of future vehicle characteristics, performance (such as electric range and efficiency) and costs to 2050 have been developed for the full range of future powertrain options (including plug-in vehicles and more conventional vehicles);
2. Consumer attitudes and behaviours have been researched through real-world trials and extensive surveys with ‘mass-market’ consumers, including a choice experiment to quantify consumers’ willingness to pay for specific vehicle attributes;
3. The requirements and costs for the supporting recharging infrastructure and its integration into the UK electricity system have been identified; and
4. The economics and carbon benefits have been evaluated in the context of plug-in vehicles as a component of the UK’s future low carbon energy and transport systems. This paper reflects work completed in mid 2011 by a consortium of Arup, Leeds University and E.ON, primarily focusing on item (4) [1] and drawing on insights from separate ETI projects into items (1) to (3). Full article

The U.S. government’s goal, announced in 2011, of putting one million PEVs on the road by 2015 represents a key milestone for the deployment of PEVs in the U.S. However, the forecasts of PEV consumer adoption are not as optimistic as manufacturers’ announced production claims. With an overarching objective of exploring alternative paths towards one-million PEVs on the road in the U.S. by 2015, this paper presents a number of possible strategies and evaluates their impacts on PEV market share. Full article

In order to analyze the approach of the main automotive players regarding the electrification path each one is following, this report assesses those aspects required for a consistent corporate product strategy. As distinctive differences are found in terms of the scope of products, some boundaries are defined based on the mobility concept, establishing the differentiation of the current automotive business into two separated industries. After analyzing each of the industries, the report focuses on four automotive OEMs and the way they are coping with the competition for profit in each scenario. The paper also analyses and assesses both each OEM strategic choice and business model. Full article

Electric vehicles are mostly used in the niche market. Compared to the common consumers, commercial uses are more suitable as target markets for electric vehicles at the initial rollout stage. The main obstacles for promoting electric vehicles are higher production cost (of which battery accounts for a major part) and paucity for public charging stations. It is relatively easy to make a breakthrough in commercial markets than in common consumer market, as far as the operational characteristics for commercial vehicles are concerned. At the present moment, testing operations for all kinds of electric commercial vehicle (BEV) throughout the world remain experimental, small-scaled, in a limited area, or still undergoing evaluation. Actual stable profit-producing examples have not yet materialized so far. This thesis probes into current operational condition of commercial vehicle fleet in Taiwan and evaluates the electrification, so as to propose potential business models in the future. Full article

This paper analyses the cost competitiveness of different electrified propulsion technologies for the German auto market in 2020. Several types of hybrid electric vehicles including parallel hybrids (with and without external charging) and a serial range extended electric vehicle are compared to a conventional car with SI engine, a full battery electric vehicle and a hydrogen powered fuel cell vehicle. Special focus lies on the maintenance and repair cost and the expected resale value of alternative vehicles, which have been integrated within one extensive total cost of ownership model. The assessment shows that the current TCO gaps for alternative drivetrains will decrease significantly by 2020 mainly driven by the reduction in production cost. Furthermore hybrid electric vehicles will profit from lower maintenance and repair cost and a higher expected resale value compared to conventional cars. Therefore, hybrid electric vehicles will be an attractive option in particular for users with high annual mileages, who can benefit from the low operating cost of EVs in combination with unlimited driving range. The analysis concludes that there will not be one dominant powertrain design in the midterm future. Hence, automakers have to manage a wide portfolio of competing drivetrain architectures, which will increase the risk and complexity of strategic decisions. Full article

In recent years, a series of incidents have drawn society’s attention to issues of environmental awareness and energy security. As a result, electric vehicles (hereafter, “EV”) are attracting attention around the world. To stimulate their economies, countries are preparing measures and policies to acquire EV-related core technologies and develop new markets quickly. In this paper, we argue that, given these circumstances, the development of open source businesses in the EV industry will contribute to solving a wide variety of problems, from industry-specific to social issues. Furthermore, we advance the hypothesis that this strategy may prove to be a model both sustainable and profitable. We qualitatively evaluate the utility of our hypothesis on the basis of the SIM-Drive Corporation’s actual performance, which has been promoting a similar business model in the EV industry. Full article

In this paper, the market potential for electric vehicles (EVs) in Flanders (Belgium) is forecasted with the use of a choice-based conjoint (CBC) analysis. In May 2011, a large-scale survey was conducted (n = 1.197). The goal of the survey was twofold: estimate the market potential for (plug-in hybrid) electric vehicles in Flanders (Belgium) and formulate recommendations for the further deployment of electric vehicles within the region of Flanders. When looking at the forecasts based on the CBC experiment, in 2020, battery electric vehicles (BEVs) could reach a market share of around 5% of the newly sold vehicles in Flanders. Plug-in hybrid electric vehicles (PHEVs) could have a market share of around 7%. In 2030, these figures could increase to respectively 15% and 29%. A sensitivity analysis reveals that, in order to increase the potential for (PH)EVs, the main focus should be on decreasing the purchase costs. Full article

For electric cars to replace fuel burners they must have intrinsic advantages beyond those seen today and cost significantly less to operate, but 125 years of evolution has made the ICE car hard to beat. A modular battery electric “ridek” composed of “ridon” and “modek” exchangeable modules offers many economies, conveniences and a business plan that cannot be matched by conventional cars. It bears the successful advantages of a mutation, matched by reproducibility. A score of the projected advantages of this new species of electric vehicle are presented herewith and it is tempting to conjecture that more will manifest themselves. It is intriguing to note that a vehicle that readily comes apart (like NASCAR racers) has several features that enhance its overall safety over that of conventional cars. Full article

This paper will provide an update and overview of the progress with the North East of England trials in the UK and provide an insight into how early adopters are using their vehicle and importantly their charging behaviour with a large number of charging points available to them. The North East of England is one of the pioneers in the wide-scale demonstration of electric vehicles in the United Kingdom. The SwitchEV trial is one of only 8 projects across the UK to have won funding through the Technology Strategy Board’s Ultra Low Carbon Vehicle (ULCV) Demonstrator Programme. As part of the three year trial, 44 full-electric vehicles have been equipped with data loggers to provide an insight into how early adopters are using their vehicles and most importantly their charging behaviour with a large number of charging points available to them. The trials correlates the driving and performance data derived from the vehicles, with charging behaviour derived from both the vehicle loggers and EV recharging infrastructure and soft data from: questionnaires; focus groups; and structured interviews with participants Full article

The project “ElectroDrive Salzburg” is a co-financed electric mobility model region of the Climate and Energy Fund in Austria. The project’s purposes are to offer electric mobility for companies as well as individuals through a selection of packages, to build up necessary charging stations for users and to implement new renewable energy sources, especially biomass. The research is divided into following parts: 1) Single measurements of specific car values and charging effects, 2) Repeated single measurements of specific car consumptions, 3) Series of measurements in practical use and 4) Continuous measurements of charging stations. The conclusion of this scientific accompanying research is that standby losses of Li-Ion battery systems are lower than ZEBRA batteries, but the overall driving consumptions (15-25 kWh/100km) are in the same range. The driving behaviors (distances and parking locations) of the model region drivers are different to the Austrian individuals. Most of the depths of discharges are between 30 and 60 % of battery capacity. The peak of the charging profile is about 0.33 kW/car and at 11pm if the charges of the electric vehicles are not controlled. Therefore in future intelligent charging controls are necessary to guarantee a stable grid and more renewable energy for battery charging. Full article

The UK’s Technology Strategy Board, with central and regional government support, has funded the world’s largest multi-site demonstration trial of ultra-low carbon passenger cars. 349 cars have been deployed, supported by the installation of approximately 500 electrical charging points. The trial will help the UK Government, vehicle manufacturers and energy suppliers understand how people use these cars and how they feel about them. Eight project teams each comprising at least one vehicle manufacturer, an energy supplier, a local authority, infrastructure provider and a university have gained funding. The trial includes two separate research activities:
1. Usage patterns – including time and duration of journeys, energy used and charging location.
2. User perception – questionnaires and interviews with users before, during and after the trial to help understand their feelings about the car and if they have adapted to use it. The first 65 cars were handed over to users on 13th December 2009. By December 2011, 349 vehicles from 19 manufacturers had been deployed over a mix of private domestic, company pool or fleet vehicles. The vehicles have undertaken over 180,000 trips covering over 1,000,000 miles. The vehicle models include the plug-in electric Tata Indica, Mercedes Smart ForTwo, Nissan Leaf, Ford Transit Connect; BMW Mini-E, Mitsubishi i-MiEV, Allied conversions of the Peugeot Tepee MPVs; the hydrogen fuelled Microcab; and performance electric sports cars including the Delta E4 Coupe and the Ecotricity conversion of the Lotus Exige. The fleet also includes plug-in versions of the diesel hybrid Land Rover Range-E and the petrol hybrid Toyota Prius. This paper provides details of the programme and results of the research to date, focusing especially on vehicle usage and perception data from the first three months of vehicle trials. Full article

Electric-vehicles have the potential for a significant substitution of diesel and gasoline vehicles, and contribute to a reduction of greenhouse gas (GHG) and particulate matter emissions. According to the European Renewable Energy Directive, the share of renewable transportation fuels should be 10% in 2020. In the project “Styrian e-mobility in 2020” the potential for reaching the target of 10% renewable fuels in 2020 has been determined by analysing different implementation scenarios. Based on a life cycle analysis, GHG and particulate matter emissions from transport services have been calculated and their potential reductions in emissions by the introduction of electric vehicles by 2020 have been determined. Reaching the European target of 10% renewable fuels in the passenger car sector by 2020 is possible with 30,700 electric-vehicles (5% of passenger cars) if the share of the additional electricity is above 50% from renewable energy and the same amount of transportation biofuel of 7% used as today. Full article

The British Low Carbon Vehicle Technology Project (LCVTP) has developed technologies for future plug-in vehicles. Simulation results indicate significantly lower tailpipe CO₂ emissions when compared to conventional internal combustion engine technology, but how good are the CO₂ savings on a life cycle basis? Do these technologies have higher embedded CO₂ from vehicle production? If so, can this be paid back within the lifetime of the vehicle? To help answer these questions, building on work completed within LCVTP, Ricardo conducted a life cycle top-down review of hybrid and EV technology architectures to estimate the CO₂ emissions associated with each phase of the vehicle’s life. Results showed that these technologies have the potential to reduce the life cycle CO₂ footprint of passenger cars, compared to today’s conventional technology. However, the higher embedded CO₂ from vehicle production has to be paid back before these savings can be realised. This carbon payback period is highly dependent on the CO₂ emissions resulting from electricity generation and transmission. This implies that the commercial role out of plug-in vehicles must happen in tandem with decarbonisation of the electricity to ensure CO₂ emissions are really reduced. Ensuring future low carbon vehicles are truly low carbon will require a shift in focus from tailpipe CO₂ to considering the environmental impact of the whole vehicle life cycle and the energy it uses. By adopting a life cycle philosophy and considering the carbon payback, vehicle manufacturers, policy makers and consumers can select the appropriate low carbon technology for their situation. Full article