Electric vehicles around the world (from top left): ◾ Electric car. Top-selling Nissan Leaf in Amsterdam ◾ High-speed rail. China's CRH5 in Beijing ◾ Electric trolleybus in São Paulo, Brazil ◾ Electric tram in Vienna, Austria ◾ U.S. manufactured electric truck, Australia ◾ BYD K9, a battery electric bus with onboard LiFePO4 battery Electric vehicle From Wikipedia, the free encyclopedia An electric vehicle (EV), also referred to as an electric drive vehicle, uses one or more electric motors or traction motors for propulsion. An electric vehicle may be powered through a collector system by electricity from off-vehicle sources, or may be self-contained with a battery or generator to convert fuel to electricity.[1] EVs include road and rail vehicles, surface and underwater vessels, electric aircraft and electric spacecraft. EVs first came into existence in the mid-19th century, when electricity was among the preferred methods for motor vehicle propulsion, providing a level of comfort and ease of operation that could not be achieved by the gasoline cars of the time. The internal combustion engine (ICE) has been the dominant propulsion method for motor vehicles for almost 100 years, but electric power has remained commonplace in other vehicle types, such as trains and smaller vehicles of all types. Contents ◾ 1 History ◾ 1.1 Experimentation ◾ 1.2 Reintroduction ◾ 2 Electricity sources ◾ 2.1 Connection to generator plants ◾ 2.2 Onboard generators and hybrid EVs ◾ 2.3 Onboard storage ◾ 3 Lithium-ion battery ◾ 4 Electric motor ◾ 5 Vehicle types ◾ 5.1 Ground vehicles Page 1 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle ◾ Electric locomotive of the Shatabdi Express in India (see gallery of multiple units) ◾ The electric, solar-powered aircraft, Solar Impulse 2 successfully circumnavigated the globe. ◾ Chinese made electric scooter in the Brazilian city of Maringá, and e-Bike, in Manhattan, New York ◾ 5.1.1 Plug-in electric vehicle ◾ 5.1.2 Hybrid EVs ◾ 5.1.3 On- and off-road EVs ◾ 5.1.4 Railborne EVs ◾ 5.1.5 Space rover vehicles ◾ 5.2 Airborne EVs ◾ 5.3 Seaborne EVs ◾ 5.4 Electrically powered spacecraft ◾ 6 Energy and motors ◾ 7 Properties of EVs ◾ 7.1 Components ◾ 7.2 Energy sources ◾ 7.3 Issues with batteries ◾ 7.4 Efficiency ◾ 7.5 Electromagnetic radiation ◾ 7.6 Charging ◾ 7.6.1 Grid capacity ◾ 7.6.2 Charging stations ◾ 7.6.3 Battery swapping ◾ 7.6.4 Chassis swapping ◾ 7.7 Other in-development technologies ◾ 7.8 Safety ◾ 7.9 Advantages and disadvantages of EVs ◾ 7.9.1 Environmental ◾ 7.9.2 Mechanical ◾ 7.9.3 Energy resilience ◾ 7.9.4 Energy efficiency ◾ 7.9.5 Cost of recharge ◾ 7.9.6 Stabilization of the grid ◾ 7.9.7 Range ◾ 7.9.8 Heating of EVs ◾ 8 Electric public transit efficiency ◾ 9 Incentives and promotion ◾ 10 Future ◾ 10.1 Improved batteries ◾ 10.2 Battery management and intermediate storage ◾ 11 EV organizations ◾ 11.1 Worldwide Page 2 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle Edison and a 1914 Detroit Electric model 47 (courtesy of the National Museum of American History) An EV and an antique car on display at a 1912 auto show ◾ 11.2 Europe ◾ 11.3 North America ◾ 11.4 Asia ◾ 12 See also ◾ 13 References ◾ 14 Further reading ◾ 15 External links History Electric motive power started in 1827, when Slovak-Hungarian priest Ányos Jedlik built the first crude but viable electric motor, provided with stator, rotor and commutator, and the year after he used it to power a tiny car.[2] A few years later, in 1835, professor Sibrandus Stratingh of University of Groningen, the Netherlands, built a small scale electric car and a Robert Anderson of Scotland is reported to have made a crude electric carriage sometime between the years of 1832 and 1839. Around the same period, early experimental electrical cars were moving on rails, too. American blacksmith and inventor Thomas Davenport built a toy electric locomotive, powered by a primitive electric motor, in 1835. In 1838, a Scotsman named Robert Davidson built an electric locomotive that attained a speed of four miles per hour (6 km/h). In England a patent was granted in 1840 for the use of rails as conductors of electric current, and similar American patents were issued to Lilley and Colten in 1847.[3] Between 1832 and 1839 (the exact year is uncertain), Robert Anderson of Scotland invented the first crude electric carriage, powered by non-rechargeable primary cells.[4] By the 20th century, electric cars and rail transport were commonplace, with commercial electric automobiles having the majority of the market. Over time their general-purpose commercial use reduced to specialist roles, as platform trucks, forklift trucks, ambulances,[5] tow tractors and urban delivery vehicles, such as the iconic British milk float; for most of the 20th century, the UK was the world's largest user of electric road vehicles.[6] Electrified trains were used for coal transport, as the motors did not use precious oxygen in the mines. Switzerland's lack of natural fossil resources forced the rapid electrification of their rail network. One of the earliest rechargeable batteries - the nickel-iron battery - was favored by Edison for use in electric cars. Page 3 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle EVs were among the earliest automobiles, and before the preeminence of light, powerful internal combustion engines, electric automobiles held many vehicle land speed and distance records in the early 1900s. They were produced by Baker Electric, Columbia Electric, Detroit Electric, and others, and at one point in history out-sold gasoline-powered vehicles. In fact, in 1900, 28 percent of the cars on the road in the USA were electric. EVs were so popular that even President Woodrow Wilson and his secret service agents toured Washington DC in their Milburn Electrics, which covered 60–70 mi (100–110 km) per charge.[7] A number of developments contributed to decline of electric cars.[8] Improved road infrastructure required a greater range than that offered by electric cars, and the discovery of large reserves of petroleum in Texas, Oklahoma, and California led to the wide availability of affordable gasoline/petrol, making internal combustion powered cars cheaper to operate over long distances.[9] Also internal combustion powered cars became ever easier to operate thanks to the invention of the electric starter by Charles Kettering in 1912,[10] which eliminated the need of a hand crank for starting a gasoline engine, and the noise emitted by ICE cars became more bearable thanks to the use of the muffler, which Hiram Percy Maxim had invented in 1897. As roads were improved outside urban areas electric vehicle range could not compete with the ICE. Finally, the initiation of mass production of gasoline-powered vehicles by Henry Ford in 1913 reduced significantly the cost of gasoline cars as compared to electric cars.[11] In the 1930s, National City Lines, which was a partnership of General Motors, Firestone, and Standard Oil of California purchased many electric tram networks across the country to dismantle them and replace them with GM buses. The partnership was convicted of conspiring to monopolize the sale of equipment and supplies to their subsidiary companies, but were acquitted of conspiring to monopolize the provision of transportation services. Experimentation In January 1990, General Motors' President introduced its EV concept two-seater, the "Impact", at the Los Angeles Auto Show. That September, the California Air Resources Board mandated major- automaker sales of EVs, in phases starting in 1998. From 1996 to 1998 GM produced 1117 EV1s, 800 of which were made available through three-year leases. Chrysler, Ford, GM, Honda, Nissan and Toyota also produced limited numbers of EVs for California drivers. In 2003, upon the expiration of GM's EV1 leases, GM crushed them. The crushing has variously been attributed to: ◾ the auto industry's successful federal court challenge to California's zero-emissions vehicle mandate, ◾ a federal regulation requiring GM to produce and maintain spare parts for the few thousands EV1s and ◾ the success of the oil and auto industries' media campaign to reduce public acceptance of EVs. A movie made on the subject in 2005-2006 was titled Who Killed the Electric Car? and released theatrically by Sony Pictures Classics in 2006. The film explores the roles of automobile manufacturers, oil industry, the U.S. government, batteries, hydrogen vehicles, and consumers, and each of their roles in limiting the deployment and adoption of this technology. Page 4 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle General Motors EV1 electric car (1996-1998), story told in movie Who Killed the Electric Car? The world's two best selling all-electric cars in history are the Nissan Leaf (left), with 240,000 global sales through September 2016, and the Tesla Model S (right), with over 150,000 units delivered through November 2016.[15] Ford released a number of their Ford Ecostar delivery vans into the market. Honda, Nissan and Toyota also repossessed and crushed most of their EVs, which, like the GM EV1s, had been available only by closed-end lease. After public protests, Toyota sold 200 of its RAV EVs to eager buyers; they later sold at over their original forty-thousand-dollar price. This lesson did not go unlearned; BMW of Canada sold off a number of Mini EV's when their Canadian testing ended. The production of the Citroën Berlingo Electrique stopped in September 2005. Reintroduction During the last few decades, environmental impact of the petroleum-based transportation infrastructure, along with the fear of peak oil, has led to renewed interest in an electric transportation infrastructure.[12] EVs differ from fossil fuel-powered vehicles in that the electricity they consume can be generated from a wide range of sources, including fossil fuels, nuclear power, and renewable sources such as tidal power, solar power, and wind power or any combination of those. The carbon footprint and other emissions of electric vehicles varies depending on the fuel and technology used for electricity generation.[13][14] The electricity may then be stored on board the vehicle using a battery, flywheel, or supercapacitors. Vehicles making use of engines working on the principle of combustion can usually only derive their energy from a single or a few sources, usually non-renewable fossil fuels. A key advantage of hybrid or plug-in electric vehicles is regenerative braking due to their capability to recover energy normally lost during braking as electricity is stored in the on-board battery. As of September 2016, series production highway- capable all-electric cars available in some countries for retail customers released to the market since 2010 include the Mitsubishi i-MiEV, Nissan Leaf, Ford Focus Electric, Tesla Model S, BMW ActiveE, Coda, Renault Fluence Z.E., Honda Fit EV, Toyota RAV4 EV, Renault Zoe, Roewe E50, Mahindra e2o, Chevrolet Spark EV, Fiat 500e, Volkswagen e-Up!, BMW i3, BMW Brilliance Zinoro 1E, Kia Soul EV, Volkswagen e-Golf, Mercedes-Benz B-Class Electric Drive, Venucia e30, BAIC E150 EV, Denza EV, Zotye Zhidou E20, BYD e5, Tesla Model X, Detroit Electric SP.01, BYD Qin EV300, and Hyundai Ioniq Electric. As of early December 2015, the Leaf, with 200,000 units sold worldwide, is the world's top-selling highway-capable all-electric car in history, followed by the Tesla Model S with global deliveries of about 100,000 units.[16] Page 5 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle As of May 2015, more than 500,000 highway-capable all-electric passenger cars and light utility vehicles have been sold worldwide since 2008, out of total global sales of about 850,000 light-duty plug- in electric vehicles.[17][18] As of May 2015, the United States had the largest fleet of highway-capable plug-in electric vehicles in the world, with about 335,000 highway legal plug-in electric cars sold in the country since 2008, and representing about 40% of the global stock.[19][20] California is the largest plug- in car regional market in the country, with almost 143,000 units sold between December 2010 and March 2015, representing over 46% of all plug-in cars sold in the U.S.[21][22][23][24] Cumulative global sales of all-electric cars and vans passed the 1 million unit milestone in September 2016.[25] Norway is the country with the highest market penetration per capita in the world, with four plug-in electric vehicles per 1000 inhabitants in 2013.[26] In March 2014, Norway became the first country where over 1 in every 100 passenger cars on the roads is a plug-in electric.[27][28] Norway also has the world's largest plug-in electric segment market share of total new car sales, 13.8% in 2014, up from 5.6% in 2013.[19][29] In June 2016, Andorra became the second country in this list, with a 6% of market share combining electric vehicles and plug-in hybrids[30] due to a strong public policy providing multiple advantages.[31] As of May 2015, there were 58,989 plug-in electric vehicles registered in Norway, consisting of 54,160 all-electric vehicles and 4,829 plug-in hybrids.[32] Electricity sources There are many ways to generate electricity, of varying costs, efficiency and ecological desirability. Connection to generator plants ◾ direct connection to generation plants as is common among electric trains, trolley buses, and trolley trucks (See also : overhead lines, third rail and conduit current collection) ◾ Online Electric Vehicle collects power from electric power strips buried under the road surface through electromagnetic induction Onboard generators and hybrid EVs (See articles on diesel-electric and gasoline-electric hybrid locomotion for information on EVs using also combustion engines). ◾ generated on-board using a diesel engine: diesel-electric locomotive ◾ generated on-board using a fuel cell: fuel cell vehicle ◾ generated on-board using nuclear energy: nuclear submarines and aircraft carriers ◾ renewable sources such as solar power: solar vehicle It is also possible to have hybrid EVs that derive electricity from multiple sources. Such as: ◾ on-board rechargeable electricity storage system (RESS) and a direct continuous connection to land-based generation plants for purposes of on-highway recharging with unrestricted highway range Page 6 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle A passenger train, taking power through a third rail with return through the traction rails An electric locomotive at Brig, Switzerland Electric bus in Santa Barbara, California ◾ on-board rechargeable electricity storage system and a fueled propulsion power source (internal combustion engine): plug-in hybrid Another form of chemical to electrical conversion is fuel cells, projected for future use. For especially large EVs, such as submarines, the chemical energy of the diesel-electric can be replaced by a nuclear reactor. The nuclear reactor usually provides heat, which drives a steam turbine, which drives a generator, which is then fed to the propulsion. See Nuclear Power A few experimental vehicles, such as some cars and a handful of aircraft use solar panels for electricity. Onboard storage These systems are powered from an external generator plant (nearly always when stationary), and then disconnected before motion occurs, and the electricity is stored in the vehicle until needed. ◾ on-board rechargeable electricity storage system (RESS), called Full Electric Vehicles (FEV). Power storage methods include: ◾ chemical energy stored on the vehicle in on-board batteries: Battery electric vehicle (BEV) ◾ kinetic energy storage: flywheels ◾ static energy stored on the vehicle in on-board electric double-layer capacitors Batteries, electric double-layer capacitors and flywheel energy storage are forms of rechargeable on-board electrical storage. By avoiding an intermediate mechanical step, the energy conversion efficiency can be improved over the hybrids already discussed, by avoiding unnecessary energy conversions. Furthermore, electro-chemical batteries conversions are easy to reverse, allowing electrical energy to be stored in chemical form. Lithium-ion battery Most electric vehicles use lithium ion batteries. Lithium ion batteries have higher energy density, longer life span and higher power density than most other practical batteries. Complicating factors include safety, durability, thermal breakdown and cost. Li-ion batteries should be used within safe temperature and voltage ranges in order to operate safely and efficiently.[33] Page 7 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle Battery electric bus powered with lithium-ion batteries Electric truck e-Force One The Chevrolet Volt is the world's top selling plug-in hybrid of all time. Global Volt/Ampera family sales passed the 100,000 unit milestone in October 2015.[36] Increasing the battery's lifespan decreases effective costs. One technique is to operate a subset of the battery cells at a time and switching these subsets.[34] Electric motor The power of a vehicle electric motor, as in other vehicles, is measured in kilowatts (kW). 100 kW is roughly equivalent to 134 horsepower, although electric motors can deliver their full torque over a wide RPM range, so the performance is not equivalent, and far exceeds a 134 horsepower (100 kW) fuel- powered motor, which has a limited torque curve. Usually, direct current (DC) electricity is fed into a DC/AC inverter where it is converted to alternating current (AC) electricity and this AC electricity is connected to a 3-phase AC motor. For electric trains, forklift trucks, and some electric cars, DC motors are often used. In some cases, universal motors are used, and then AC or DC may be employed. In recent production vehicles, various motor types have been implemented, for instance: Induction motors within Tesla Motor vehicles and permanent magnet machines in the Nissan Leaf.[35] Vehicle types It is generally possible to equip any kind of vehicle with an electric powertrain. Ground vehicles Plug-in electric vehicle A plug-in electric vehicle (PEV) is any motor vehicle that can be recharged from any external source of electricity, such as wall sockets, and the electricity stored in the rechargeable battery packs drives or contributes to drive the wheels. PEV is a subcategory of electric vehicles that includes all-electric or battery electric vehicles (BEVs), plug-in hybrid vehicles, (PHEVs), and electric vehicle conversions of hybrid electric vehicles and conventional internal combustion engine vehicles.[37][38][39] Page 8 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle An electric powertrain used by Power Vehicle Innovation for trucks or buses[56] Cumulative global sales totaled over 1.5 million plug-in cars and utility vans by the end of May 2016.[40] As of June 2016, the world's top selling plug-in electric cars are the Nissan Leaf, with global sales of more than 228,000 units, followed by the all-electric Tesla Model S with about 129,400 units sold worldwide, the Chevrolet Volt plug-in hybrid, which together with its sibling the Opel/Vauxhall Ampera has combined global sales of about 117,300 units, the Mitsubishi Outlander P-HEV with about 107,400 units, and the Prius Plug-in Hybrid with over 75,400 units.[41] Hybrid EVs A hybrid electric vehicle combines a conventional (usually fossil fuel-powered) powertrain with some form of electric propulsion. As of April 2016, over 11 million hybrid electric vehicles have been sold worldwide since their inception in 1997. Japan is the market leader with more than 5 million hybrids sold, followed by the United States with cumulative sales of over 4 million units since 1999, and Europe with about 1.5 million hybrids delivered since 2000.[42] Japan has the world's highest hybrid market penetration. By 2013 the hybrid market share accounted for more than 30% of new standard passenger car sold, and about 20% new passenger vehicle sales including kei cars.[43] Norway ranks second with a hybrid market share of 6.9% of new car sales in 2014, followed by the Netherlands with 3.7%[44] Global hybrid sales are by Toyota Motor Company with more than 9 million Lexus and Toyota hybrids sold as of April 2016,[45] followed by Honda Motor Co., Ltd. with cumulative global sales of more than 1.35 million hybrids as of June 2014,[46][47][48] Ford Motor Corporation with over 424,000 hybrids sold in the United States through June 2015,[49][50][51][52][53] and the Hyundai Group with cumulative global sales of 200,000 hybrids as of March 2014, including both Hyundai Motor Company and Kia Motors hybrid models.[54] As of April 2016, worldwide hybrid sales are led by the Toyota Prius liftback, with cumulative sales of over 3.7 million units. The Prius nameplate has sold more than 5.7 million hybrids up to April 2016.[55] On- and off-road EVs EVs are on the road in many functions, including electric cars, electric trolleybuses, electric buses, battery electric buses, electric trucks, electric bicycles, electric motorcycles and scooters, neighborhood electric vehicles, golf carts, milk floats, and forklifts. Off-road vehicles include electrified all-terrain vehicles and tractors. Railborne EVs The fixed nature of a rail line makes it relatively easy to power EVs through permanent overhead lines or electrified third rails, eliminating the need for heavy onboard batteries. Electric locomotives, electric trams/streetcars/trolleys, electric light rail systems, and electric rapid transit are all in common use today, especially in Europe and Asia. Page 9 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle A streetcar (or Tram) drawing current from a single overhead wire through a pantograph. Oceanvolt SD8.6 electric saildrive motor Since electric trains do not need to carry a heavy internal combustion engine or large batteries, they can have very good power-to-weight ratios. This allows high speed trains such as France's double-deck TGVs to operate at speeds of 320 km/h (200 mph) or higher, and electric locomotives to have a much higher power output than diesel locomotives. In addition, they have higher short-term surge power for fast acceleration, and using regenerative brakes can put braking power back into the electrical grid rather than wasting it. Maglev trains are also nearly always EVs. Space rover vehicles Manned and unmanned vehicles have been used to explore the Moon and other planets in the solar system. On the last three missions of the Apollo program in 1971 and 1972, astronauts drove silver- oxide battery-powered Lunar Roving Vehicles distances up to 35.7 kilometers (22.2 mi) on the lunar surface. Unmanned, solar-powered rovers have explored the Moon and Mars. Airborne EVs Since the beginning of the era of aviation, electric power for aircraft has received a great deal of experimentation. Currently flying electric aircraft include manned and unmanned aerial vehicles. Seaborne EVs Electric boats were popular around the turn of the 20th century. Interest in quiet and potentially renewable marine transportation has steadily increased since the late 20th century, as solar cells have given motorboats the infinite range of sailboats. Electric motors can and have also been used in sailboats instead of traditional diesel engines.[57] Electric ferries operate routinely.[58] Submarines use batteries (charged by diesel or gasoline engines at the surface), nuclear power, fuel cells[59] or Stirling engines to run electric motor-driven propellers. Electrically powered spacecraft Electric power has a long history of use in spacecraft.[60][61] The power sources used for spacecraft are batteries, solar panels and nuclear power. Current methods of propelling a spacecraft with electricity include the arcjet rocket, the electrostatic ion thruster, the Hall effect thruster, and Field Emission Electric Propulsion. A number of other methods have been proposed, with varying levels of feasibility. Page 10 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle A trolleybus uses two overhead wires to provide electric current supply and return to the power source An electric bus at Lucerne Battery electric bus by BYD in the Netherlands Energy and motors Most large electric transport systems are powered by stationary sources of electricity that are directly connected to the vehicles through wires. Electric traction allows the use of regenerative braking, in which the motors are used as brakes and become generators that transform the motion of, usually, a train into electrical power that is then fed back into the lines. This system is particularly advantageous in mountainous operations, as descending vehicles can produce a large portion of the power required for those ascending. This regenerative system is only viable if the system is large enough to utilise the power generated by descending vehicles. In the systems above motion is provided by a rotary electric motor. However, it is possible to "unroll" the motor to drive directly against a special matched track. These linear motors are used in maglev trains which float above the rails supported by magnetic levitation. This allows for almost no rolling resistance of the vehicle and no mechanical wear and tear of the train or track. In addition to the high-performance control systems needed, switching and curving of the tracks becomes difficult with linear motors, which to date has restricted their operations to high-speed point to point services. Properties of EVs Components The type of battery, the type of traction motor and the motor controller design vary according to the size, power and proposed application, which can be as small as a motorized shopping cart or wheelchair, through pedelecs, electric motorcycles and scooters, neighborhood electric vehicles, industrial fork-lift trucks and including many hybrid vehicles. Energy sources Although EVs have few direct emissions, all rely on energy created through electricity generation, and will usually emit pollution and generate waste, unless it is generated by renewable source power plants. Since EVs use whatever electricity is delivered by their electrical utility/grid operator, EVs can be made more or less efficient, polluting and expensive to run, by modifying the electrical generating stations. This would be done by an electrical utility under a government energy policy, in a timescale negotiated between utilities and government. Page 11 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle Old: Banks of conventional lead-acid car batteries are still commonly used for EV propulsion Fossil fuel vehicle efficiency and pollution standards take years to filter through a nation's fleet of vehicles. New efficiency and pollution standards rely on the purchase of new vehicles, often as the current vehicles already on the road reach their end-of-life. Only a few nations set a retirement age for old vehicles, such as Japan or Singapore, forcing periodic upgrading of all vehicles already on the road. EVs will take advantage of whatever environmental gains happen when a renewable energy generation station comes online, a fossil-fuel power station is decommissioned or upgraded. Conversely, if government policy or economic conditions shifts generators back to use more polluting fossil fuels and internal combustion engine vehicles (ICEVs), or more inefficient sources, the reverse can happen. Even in such a situation, electrical vehicles are still more efficient than a comparable amount of fossil fuel vehicles. In areas with a deregulated electrical energy market, an electrical vehicle owner can choose whether to run his electrical vehicle off conventional electrical energy sources, or strictly from renewable electrical energy sources (presumably at an additional cost), pushing other consumers onto conventional sources, and switch at any time between the two. Issues with batteries Efficiency Because of the different methods of charging possible, the emissions produced have been quantified in different ways.[62] Plug-in all-electric and hybrid vehicles also have different consumption characteristics.[63] Electromagnetic radiation Electromagnetic radiation from high performance electrical motors has been claimed to be associated with some human ailments, but such claims are largely unsubstantiated except for extremely high exposures.[64] Electric motors can be shielded within a metallic Faraday cage, but this reduces efficiency by adding weight to the vehicle, while it is not conclusive that all electromagnetic radiation can be contained. Charging Grid capacity If a large proportion of private vehicles were to convert to grid electricity it would increase the demand for generation and transmission, and consequent emissions. However, overall energy consumption and emissions would diminish because of the higher efficiency of EVs over the entire cycle. In the USA it has been estimated there is already nearly sufficient existing power plant and transmission infrastructure, assuming that most charging would occur overnight, using the most efficient off-peak base load sources. [65] Page 12 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle 75 watt-hour/kilogram lithium ion polymer battery prototypes. Newer Li-poly cells provide up to 130 Wh/kg and last through thousands of charging cycles. BYD e6 taxi in Shenzhen, China. Recharging in 15 Minutes to 80 Percent A BYD electric bus in Shanghai at a charging station In the UK however, things are different. While National Grid’s high-voltage electricity transmission system can currently manage the demand of 1 million electric cars, Steve Holliday (CEO National Grid PLC) said, “penetration up and above that becomes a real issue. Local distribution networks in cities like London may struggle to balance their grids if drivers choose to all plug in their cars at the same time." Charging stations EVs typically charge from conventional power outlets or dedicated charging stations, a process that typically takes hours, but can be done overnight and often gives a charge that is sufficient for normal everyday usage. However, with the widespread implementation of electric vehicle networks within large cities, such as those provided by POD Point [1] (http://www.pod-point.com/) in the UK and Europe, EV users can plug in their cars whilst at work and leave them to charge throughout the day, extending the possible range of commutes and eliminating range anxiety. A recharging system that avoids the need for a cable is Curb Connect, patented in 2012[66] by Dr Gordon Dower. In this system, electrical contacts are fitted into curbs, such as angle parking spaces on city streets. When a suitably authorized vehicle is parked so that its front end overhangs the curb, the curb contacts become energized and charging occurs. Another proposed solution for daily recharging is a standardized inductive charging system such as Evatran's Plugless Power. Benefits are the convenience of parking over the charge station and minimized cabling and connection infrastructure.[67][68][69] Qualcomm is trialling such a system in London in early 2012. [70][71] Yet another proposed solution for the typically less frequent, long distance travel is "rapid charging", such as the Aerovironment PosiCharge line (up to 250 kW) and the Norvik MinitCharge line (up to 300 kW). Ecotality is a manufacturer of Charging Stations and has partnered with Nissan on several installations. Battery replacement is also proposed as an alternative, although no OEMs including Nissan/Renault have any production vehicle plans. Swapping requires standardization across platforms, models and manufacturers. Swapping also requires many times more battery packs to be in the system. Page 13 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle A battery electric bus charging station in Geneva, Swiss One type of battery "replacement" proposed, vanadium redox battery, is much simpler: while the latest generation of vanadium redox battery only has an energy density similar to lead-acid, the charge is stored solely in a vanadium-based electrolyte, which can be pumped out and replaced with charged fluid. The vanadium battery system is also a potential candidate for intermediate energy storage in quick charging stations because of its high power density and extremely good endurance in daily use. System cost however, is still prohibitive. As vanadium battery systems are estimated to range between $350–$600 per kWh, a battery that can service one hundred customers in a 24- hour period at 50 kWh per charge would cost $1.8-$3 million. According to Department of Energy research conducted at Pacific Northwest National Laboratory, 84% of existing vehicles could be switched over to plug-in hybrids without requiring any new grid infrastructure.[72] In terms of transportation, the net result would be a 27% total reduction in emissions of the greenhouse gases carbon dioxide, methane, and nitrous oxide, a 31% total reduction in nitrogen oxides, a slight reduction in nitrous oxide emissions, an increase in particulate matter emissions, the same sulfur dioxide emissions, and the near elimination of carbon monoxide and volatile organic compound emissions (a 98% decrease in carbon monoxide and a 93% decrease in volatile organic compounds).[73] The emissions would be displaced away from street level, where they have "high human-health implications."[74] Battery swapping Instead of recharging EVs from electric socket, batteries could be mechanically replaced on special stations in a couple of minutes (battery swapping). Batteries with greatest energy density such as metal-air fuel cells usually cannot be recharged in purely electric way. Instead, some kind of metallurgical process is needed, such as aluminum smelting and similar. Silicon-air, aluminum-air and other metal-air fuel cells look promising candidates for swap batteries. [75][76] Any source of energy, renewable or non-renewable, could be used to remake used metal-air fuel cells with relatively high efficiency. Investment in infrastructure will be needed. The cost of such batteries could be an issue, although they could be made with replaceable anodes and electrolyte. Chassis swapping Instead of replacing batteries, it is possible to replace the entire chassis (including the batteries, electric motor and wheels) of an electric Modular vehicle. Such a system was patented in 2000[77] by Dr Gordon Dower and three road-licensed prototypes have been built by the Ridek Corporation (http://ridek.com) in Point Roberts, Washington. Page 14 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle Dr Dower has proposed that an individual might own only the body (or perhaps a few different style bodies) for their vehicle, and would lease the chassis from a pool, thereby reducing the depreciation costs associated with vehicle ownership. Other in-development technologies Conventional electric double-layer capacitors are being worked to achieve the energy density of lithium ion batteries, offering almost unlimited lifespans and no environmental issues. High-K electric double- layer capacitors, such as EEStor's EESU, could improve lithium ion energy density several times over if they can be produced. Lithium-sulphur batteries offer 250 Wh/kg.[78] Sodium-ion batteries promise 400 Wh/kg with only minimal expansion/contraction during charge/discharge and a very high surface area.[79] Researchers from one of the Ukrainian state universities claim that they have manufactured samples of pseudocapacitor based on Li-ion intercalation process with 318 Wh/kg specific energy, which seem to be at least two times improvement in comparison to typical Li-ion batteries.[80] Safety The United Nations in Geneva (UNECE) has adopted the first international regulation (Regulation 100) on safety of both fully electric and hybrid electric cars, with the intent of ensuring that cars with a high voltage electric power train, such as hybrid and fully EVs, are as safe as combustion-powered cars. The EU and Japan have already indicated that they intend to incorporate the new UNECE Regulation in their respective rules on technical standards for vehicles[81] There is a growing concern about the safety of EVs, given the demonstrated tendency of the Lithium-ion battery, most promising for EV use because of its high energy density, to overheat, possibly leading to fire or explosion, especially when damaged in a crash. The U.S. National Highway Traffic Safety Administration opened a defect investigation of the Chevy Volt on November 25, 2011 amid concerns over the risk of battery fires in a crash. At that time, automotive consulting firm CNW Marketing Research reported a decline in consumer interest in the Volt, citing the fires as having made an impact on consumer perception.[82] Consumer response impelled GM to make safety enhancements to the battery system in December, and the NHTSA closed its investigation on January 20, 2012, finding the matter satisfactorily resolved with "no discernible defect trend" remaining. The agency also announced it has developed interim guidance to increase awareness and identify appropriate safety measures regarding electric vehicles for the emergency response community, law enforcement officers, tow truck operators, storage facilities and consumers.[83][84] Advantages and disadvantages of EVs Environmental EVs release no tail pipe air pollutants at the place where they are operated. They also typically generate less noise pollution than an internal combustion engine vehicle, whether at rest or in motion.[85] The energy that electric and hybrid cars consume is usually generated by means that have environmental Page 15 of 27 Electric vehicle - Wikipedia 12/28/2016 https://en.wikipedia.org/wiki/Electric_vehicle