ELECTRIC VEHICLE

A streetcar drawing current from a single overhead wire, returning current through the rails and ground

An electric locomotive, taking power through a pantograph

An 'electric vehicle', or EV, is a vehicle with one or more electric motors for propulsion. The motion may be provided either by wheels or propellers driven by rotary motors, or in the case of tracked vehicles, by linear motors.
The energy used to propel the vehicle may be obtained from several sources, some of them more ecological than others:

★ from an on-board rechargeable energy storage system (RESS):

★
★ from chemical energy stored on the vehicle in on-board batteries: Battery electric vehicle (BEV)

★
★ from static energy stored on the vehicle in on-board supercapacitors

★
★ from rotational storage: flywheels

★ from both an on-board rechargeable energy storage system (RESS) and a fueled propulsion power source (internal combustion engine): hybrid vehicle (as in a diesel-electric locomotive ), including plug-in hybrid

★ generated on-board using a fuel cell: fuel cell vehicle

★ generated on-board using nuclear energy, on nuclear submarines and aircraft carriers

★ from renewable sources such as wind and solar

★ from a direct connection to land-based generation plants, as is common in electric trains and trolley buses (See also : third rail and conduit current collection)

★ from both an on-board rechargeable energy storage system and a direct continuous connection to land-based generation plants for purposes of on-highway recharging with unrestricted highway range.
Electric vehicles can include electric airplanes, electric boats, and electric motorcycles and scooters.

History

Energy

Electric motor

Large-scale electric transport: energy and motors

Advantages of electric vehicles

Issues regarding electric vehicles

Issues with batteries

Efficiency incentives

USA

European Union

Future

Improved long term energy storage and nano batteries

Introduction of Battery Management and Intermediate Storage

Electric Vehicle Organizations

History

Main articles: history of the electric vehicle

Edison and a 1914 Detroit Electric, model 47 (courtesy of the National Museum of American History)

Electric motive power started with a small railway operated by a miniature electric motor, built by Thomas Davenport in 1835. In 1838, a Scotsman named Robert Davidson built an electric locomotive that attained a speed of four miles an hour. 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. ^[1]
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. ^[2]
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, tow tractors and urban delivery vehicles, such as the iconic British milk float.
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.
Electric vehicles 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 the early 20th century, 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 for this conspiracy, but the ruling was overturned in a higher court. Electric tram line technologies could be used to recharge BEVs and PHEVs on the highway while the user drives, providing virtually unrestricted driving range. The technology is old and well established (see : Conduit current collection, Nickel-iron battery). The infrastructure has not been built.

EV1s crushed by General Motors only 5 years after production

From 1996 to 1998 during emissions reductions regulations GM produced 1117 of their EV1 models, 800 of which were made available through 3-year leases. In 2003, upon the expiration of EV1 leases, GM crushed them. The reason for the crushing is not clear, but has variously been attributed to (1) the auto industry's successful challenge to California law requiring zero-emissions vehicles or (2) a federal regulation requiring GM to produce and maintain spare parts for the few thousands EV1s or (3) a conspiracy to remove the dream of electric vehicles from the public consciousness. 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 US government, batteries, hydrogen vehicles, and consumers, and each of their roles in limiting the deployment and adoption of this technology.

Energy

A passenger railroad, taking power through a third rail with return through the traction rails

Chemical energy is a common independent energy source. Chemical energy is converted to electrical energy, which is then regulated and fed to the drive motors. Chemical energy is usually in the form of diesel or petrol (gasoline). The liquid fuels are usually converted into electricity by an electrical generator powered by an internal combustion engine or other heat engine. This approach is known as diesel-electric or gasoline-electric hybrid locomotion, that produces greenhouse gases.
Another common form of chemical to electrical conversion is by electro-chemical devices. These include fuel cells and batteries. By avoiding an intermediate mechanical step, the energy conversion efficiency is dramatically improved over the chemical-thermal-mechanical-electrical-mechanical process already discussed. This is due to the higher carnot efficiency through directly oxidizing the fuel and by avoiding several unnecessary energy conversions. Furthermore, electro-chemical batteries conversions are easy to reverse, allowing electrical energy to be stored in chemical form.
For especially large electric vehicles, 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. This energy produces nuclear waste.

Electric motor

The power of a vehicle electric motor, as in other vehicles, is measured in kW. 100 kW is roughly equivalent to 134 horsepower.

Large-scale electric transport: energy and motors

A trolleybus uses two overhead wires to provide electrical current supply and return to the power source

Most large electric transport systems are powered by stationary sources of electricity that are directly connected to the vehicles through wires. Due to the extra infrastructure and difficulty in handling arbitrary travel, most directly connected vehicles are owned publicly or by large companies. These forms of transportation are covered in more detail in metros, trams, electric locomotives, and trolleybuses.
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. Levitation and forward motion are two independent effects; the forward motive force normally requires external power, although some types, such as Inductrack, achieve levitation at low speeds without any. 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.

Advantages of electric vehicles

Electric motors are mechanically very simple, and release almost no air pollutants at the place where they are operated.
Electric motors often achieve 90% energy conversion efficiency over the full range of speeds and power output and can be precisely controlled. They can also be combining with regenerative braking systems that have the ability to convert movement energy back into stored electricity. This can be used to reduce the wear on brake systems (and consequent brake pad dust) and reduce the total energy requirement of a trip, especially effective for start-and-stop city use.
They can be finely controlled and provide high torque from rest, unlike internal combustion engines, and do not need gears to match power curves. This removes the need for gearboxes and torque converters.
Another advantage is that electric vehicles typically have less vibration and noise pollution than a vehicle powered by an internal combustion engine, whether it is at rest or in motion.

Issues regarding electric vehicles

Although electric vehicles have few direct emissions, all rely on energy created through electricity generation which will emit pollution unless it is from a renewable source. If a large proportion of private vehicles were to convert to plug-in electricity, there would be a significant need for generation and transmission capacity, even if most charging occured overnight drawing power from the most efficient off-peak base load.
Electromagnetic radiation, , from high performance electrical motors has been claimed to be associated with some human ailments. Electric motors can be shielded within a metallic Faraday's cage, but this adds weight to the vehicle and it is not conclusive that all electromagnetic radiation can be contained.

Issues with batteries

Banks of conventional lead-acid car batteries are needed for EV propulsion

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.

Many types of EV use batteries, which have an environmental impact through their construction, use, disposal or recycling. Common batteries are expensive and have a shorter life than the vehicle itself, typically needing replacement every 3 years.
Despite the higher energy efficiency, electro-chemical vehicles have been beset by a technical issue which has prevented them from replacing the more cumbersome heat engines: energy storage. Fuel cells are fragile, sensitive to contamination, and require external reactants such as hydrogen. Batteries currently used are either not mass-produced, leading to high per-unit prices, or end up being a significant (25%-50%) portion of the final vehicle mass, in the case of conventional lead-acid technology. Both have lower energy and power density than petroleum fuels.
The efficiency and storage capacity of the current generation of common deep cycle lead acid batteries decreases with lower temperates, and diverting power to run a heating coil reduces efficiency and range by up to 40%. In the New York City metropolitan area, the running costs of an electric car using standard marine lead-acid batteries, charged only from the mains, has been calculated to cost about 3 times more than a conventional compact gasoline car.
Recent advances in battery efficiency, capacity, materials, safety, toxicity and durability are likely to allow these superior characteristics to be applied in car-sized EVs.
Charging and operation of batteries typically results in the emission of hydrogen, oxygen and sulfur, which are naturally occurring and normally harmless. Early Citicar owners discovered that, if not vented properly, unpleasant sulfur smells would leak into the the cabin immediately after charging.

Efficiency incentives

USA

Qualifying electric vehicles purchased new are eligible for a one-time federal tax credit that equals 10% of the cost of the vehicle up to $4,000, provided under Section 179A of the Energy Policy Act of 1992; it was extended through 2007 by the Working Families Tax Relief Act of 2004.
A tax deduction of up to $100,000 per location is available for qualified electric vehicle recharging property used in a trade or business
Other incentives: http://www.eere.energy.gov/afdc/laws/incen_laws.html#fed

European Union

Directive 2006/32/EC of the European Parliament and of the Council of 5 April 2006 on energy end-use efficiency and energy services includes measures to promote efficiente vehicles.

Future

Main articles: Battery electric vehicle

Eliica Battery Electric Car with 370 km/h top speed and 200 km range

The number of US survey respondents willing to pay $4,000 more for a plug-in hybrid car increased from 17% in 2005 to 26% in 2006.

Several start-up companies, like Tesla Motors and Phoenix Motorcars, will have powerful battery-electric vehicles available to the public in 2008. Battery and energy storage technology is advancing rapidly. Electric cars are perfectly useful as second household vehicle for usual short and medium distance trips of 100 to 250 miles per charge. The range issue will be improved by technologies such as Plug-in hybrid electric vehicles which are capable of using traditional fuels for unlimited range.
General Motors is working on a concept car Chevrolet Volt that uses a small internal combustion engine hooked to an electrical generator to resupply the batteries. They call it an electric vehicle with a "range extender" that can extend the range up to 640 miles.

Improved long term energy storage and nano batteries

There have been several developments which could bring back electric vehicles outside of their current fields of application, as scooters, golf cars, neighborhood vehicles, in industrial operational yards and indoor operation. First, advances in lithium-based battery technology, in large part driven by the consumer electronics industry, allow full-sized, highway-capable electric vehicles to be propelled as far on a single charge as conventional cars go on a single tank of gasoline. Lithium batteries have been made safe, can be recharged in minutes instead of hours, and now last longer than the typical vehicle. The production cost of these lighter, higher-capacity lithium batteries is gradually decreasing as the technology matures and production volumes increase.

Introduction of Battery Management and Intermediate Storage

Another improvement was to decouple the electric motor from the battery through electronic control while employing ultra-capacitors to buffer large but short power demands and regenerative braking energy. The development of new cell types combined with intelligent cell management improved both weak points mentioned above. The cell management involves not only monitoring the health of the cells but also a redundant cell configuration (one more cell than needed). With sophisticated switched wiring it is possible to condition one cell while the rest are on duty.