Electric vehicles are about 2.5 times more energy efficient than their counterparts which are powered solely by internal combustion engines. This high energy efficiency is the main reason why electric vehicles can contribute to lower the CO2 emission and energy consumption of traffic substantially. Electric vehicles have zero tailpipe exhaust emissions and thus contribute substantially to a better air quality. Additionally, electric vehicles are inherently silent and can help to reduce the noise levels in cities. However, the market share of electric vehicles is currently still very small and consists mainly of small vehicles intended for urban transport. Purchase costs of electric vehicles are high compared to similar sized ICE vehicles. These high purchase costs are predominantly caused by the high costs of the battery pack needed in the vehicle. Moreover a recharging network with sufficient coverage is not yet available in most countries.
Electric vehicles are propelled solely by electric motors. There are three main types of electric vehicles:
The Battery Electric Vehicle does not have an internal generator to produce electricity, all the electricity has to be obtained from the power grid. Examples are the Citroen EVie, Mitsubishi iMiev and the Think (van Agt, 2010).
The Series Hybrid vehicle can obtain its electricity from the power grid but has additionally a small internal combustion engine which serves as a generator to recharge the battery and offers an extended driving range. The combustion engine does not directly propel the vehicle. Examples are the Opel Ampera, GM Volt and the Volvo Recharge. The third group of electric vehicles are hydrogen fuel cell vehicles. These vehicles can also obtain their electricity from the power grid but in addition, the fuel cell can serve as a generator to recharge the battery, which also extends the driving range. Examples are the Honda Clarity and the Toyota FCHV. In the following we focus on battery electric vehicles.
There are three main technical differences between a car run on an internal combustion engine and an electric car:
In addition, whilst an internal combustion engines contains lots of tubes, e.g. to transport the fuel, an electric engine contains a large amount of electric wiring. (Brain, 2005).
It is technically possible to convert a gasoline-powered vehicle to an electric vehicle; however, the associated costs are relatively high. (US Department of Energy, 2010) An explanation of how this conversion works can be found here.
The main barriers for a wider user of electric vehicles are related to the batteries and to the recharging infrastructure. Batteries for use in electric cars are still expensive and have relatively limited driving ranges. Most existing EV need to be recharged after a maximum of 150 to 300 km. Completely recharging the batteries may take 4 to 8 hours. (US Department of Energy, 2010b). The widespread use of electric vehicles requires an extensive recharging infrastructure. The absence of this infrastructure may lead to reluctance to buy electric vehicles due to the fear of getting stranded with empty batteries.
The main technical obstacles which hamper the introduction are how to standardize the cords and connectors used for recharging, the decision to employ an on- or off-board charger and to development of an accurate state of charge meter for the battery. (Markel, 2010).
The market share of battery electric vehicles is still very limited and comprises mainly of small vehicles intended for urban transport (van Agt, 2010). By the end of 2012 there was over 180,000 global stock of electric vehicles and global sales more than doubled from 2011 to 2012. However, this share only account for approximately 0.02% of total passenger cars globally (IEA, 2013). 38% of this stock is concentrated in the United States with Japan accounting for 24% and China next with 6.2% of the total.
Moreover, the purchase costs for electric vehicles are still relatively high due to the high costs of the required battery pack. To lower the purchase costs of the vehicle only relatively small battery packs are installed, limiting the driving range, which makes electric vehicles currently only suitable for urban transport. Nevertheless, the technology used in electric cars is largely proven and a breakthrough can be expected when the costs and weight of the battery pack are lowered sufficiently. Contribution of the technology to economic development (including energy market support)
Depending on where a country sources its gasoline and how it produces electricity, electric vehicles may improve energy security, as they may lower the dependency on imported gasoline.
The energy efficiency of electric cars is about 2.5 times better than their fossil fuel counterparts, which is the main reason why electric cars can lower the greenhouse gas emissions of road traffic and reduce the demand for oil. The actual greenhouse gas emission associated with the use of battery electric vehicles depends largely on the way the required electricity has been produced. Employing coal fired electricity plants to generate the electricity will marginally lower the CO2 emissions of an electric vehicle compared to similar sized vehicles with an internal combustion engine. However, using renewable electricity will lower the greenhouse gas emissions considerably. Electric vehicles might even provide a way to make the electricity sector more sustainable, if the batteries in the vehicles could be used to store the variable output of wind and solar-based power generation (Nieuwenhout et al, 2009).
Electric vehicles have no tail-pipe emission of air pollutants such as NOx and soot, which means that they can substantially contribute to improving local air quality, especially in urban areas. The global improvement of the air quality however, is determined by the way the electricity used is produced, e.g. fossil fuel fired power plants can have substantial emissions of NOx and soot when no appropriate measures are taken.
Road traffic is responsible for the majority of noise in cities. Electric vehicles are very quiet and can help to reduce noise levels in cities.
In the long-term electric vehicles are important for countries seeking to decarbonise the transport sector. Figure ? below highlights the important role that the transport sector will play in a future energy system that would limit the rise in global temperatures to 2⁰C by 2050 under the IEAs “2DS” scenario. In this scenario the transport sectors potential share of CO2 reductions would be 21% by 2050. To meet this target 75% of all vehicle sales by 2050 would need to be plug-in electric.
The high cost of an electric vehicle over the conventional alternative is mainly determined by the costs of the lithium ion battery pack. Recent developments in lithium-ion batteries make it likely that these additional costs can be reduced from the current level of about €15,000 in prototypes to an expected level of around €3,000 in 2020. This requires the battery to be about €200-250 per kWh (Nieuwenhout et al, 2009). The 2007 prices for high energy batteries range from €800/kWh to €1000/kWh (Pesaran et al, 2009). The medium term cost goals of these batteries are €500/kWh in 2012 and €300/kWh in 2016. BYD’s first commercial electric car, the E6 model, is expected to be available for sale in the US for 40’000 USD in 2010. (People’s Daily Online, 2010)
In addition, there is a need for investment into the recharging infrastructure. This infrastructure needs to be standardized in a way that every brand of electric vehicle can recharge at every recharging station. A simple recharging point at a private house or at an office site costs about $ 1800,-. However, a public recharging station, with the necessary electronics to make contact with the bank is estimated to cost about $ 18.000,-. (Roeterdink, 2010).
Project developers of projects deploying electric vehicles can use the following CDM methodology: AMS-III.C.: Emission reductions by electric and hybrid vehicles.
Author affiliation: Energy research Centre of the Netherlands (ECN), Policy Studies
Stanford researchers have designed a novel pomegranate inspired hierarchical structure which improves the energy density cycle life Coulombic efficiency and cost efficiency of silicon-based anode for Li-ion Li-O2 and Li-S batteries. The prototype successfully demonstrated superior cycle life (1000 cycles with 97% capacity retention) low electrode/electrolyte contact area for improvement of Coulombic efficiency and increased tap density.
Project ID: ENG0098A Invention Description and Novelty: A common requirement for large stacks of electrochemical cells used in electric and hybrid vehicles is the need to measure individual or groups of cell voltages almost simultaneously. The principal problem with current techniques of voltage measurement is that a small error in measuring the nodal voltages translates into a large relative error in the measurement of segment voltages. This technology provides an electronic circuit for measuring voltage signals in an energy storage device.
Background:Wireless power transfer (WPT) based on magnetic coupling is becoming widely accepted as a means of transferring power over small to medium distances. WPT systems show promise for charging electric vehicle batteries electronic devices and other technologies. Stationary wireless charging systems have relatively high efficiencies (>90%) if the source and receiver coils are well aligned.
Vehicle to Grid (V2G) involves using excess battery power from electric vehicles such as Battery Electric Vehicles and Plug-in Hybrid Electric Vehicles to help balance the load of localized power grid segments during peak hours. The storage in electric vehicles has not been used previously by the electric grid. There has never been any business that negotiates between grid operator power need and automobiles.
Developing electric thrust systems for displacement boats. Electric thrust systems for displacement boats will increasingly become the standard for both commercial and recreation boats due to environment-friendliness and functionality perspectives. Such implementations are greener and all-electric systems enable simpler more sophisticated and more reliable control of a boat’s thrust navigation environmental and human support systems.
The lithium battery industry is undergoing rapid expansion now representing the largest segment of the portable battery industry and dominating the computer cell phone and camera power source industry. Beyond consumer electronics LIBs are also growing in popularity for military electric vehicle and aerospace applications. Lithium-ion batteries are a family of rechargeable battery types in which lithium ions move from a negative electrode to the positive electrode during discharge and back when charging. Compared to graphite anodes much higher capacities are expected in silicon materials.
Background: In recent years there has been a greater interest in making more energy efficient automobiles. A number of plug-in vehicles (PEVs) or hybrid electric vehicles (HEVs) are offered by nearly every automaker today. Although these vehicles offer a cleaner and more energy efficient alternative to traditional petroleum-fueled vehicles mainstream consumer acceptance of these technologies is stymied by considerations of their premium price limited travel range and extended charging times all consequences of current battery technologies.
Gate-drive technology is traditionally an open-loop passive method that has no real-time control of a semiconductor power device & switching speed overshoot and switching power losses. The technology is unreliable and cannot be optimized over different operating voltages and current conditions. It suffers high transient overshoots at voltage and current if gate resistance is reduced to minimize the switching loss. A technology that can decouple the two issues with a satisfactory solution is needed.
Novelty: This invention provides both a combined battery/ultracapacitor energy storage system and battery chargers associated with these systems. First it combines an ultracapacitor with a battery to optimally power both high current surges and more constant demands. The ultracapacitor provides the high current power thereby insulating the battery from such uses. Second the technology introduces a circuit with a switch and control device to monitor the current load on the system and regulate the battery charging cycle accordingly.
A Northwestern investigator has developed an algorithm that facilitates the planning of future electric charging station infrastructure. With an expected increase in electric vehicles (EVs) over the next few years the availability of charging stations will become essential. This information system will enable key decision makers to deploy such an infrastructure by accounting for several key factors including: (1) EV demand; (2) the location of stations; and (3) the implied service time on car owners.