An electric car is an automobile that is propelled by one or more electric motors, using energy stored in rechargeable batteries.
Since 2008, a renaissance in electric vehicle manufacturing occurred due to advances in batteries, concerns about increasing oil prices, and the desire to reduce greenhouse gas emissions. Several national and local governments have established tax credits, subsidies, and other incentives to promote the introduction and now adoption in the mass market of new electric vehicles depending on battery size and their all-electric range. The current maximum tax credit allowed by the US Government is $7,500 per car. Compared with cars with internal combustion (IC) engines, electric cars are quieter and have no tailpipe emissions. When recharged by low-emission electrical power sources, electric vehicles can reduce greenhouse gas emissions compared to IC engines. Where oil is imported, use of electric vehicles can reduce imports. However, a proper analysis of the overall benefit/efficiency of an electric vehicle must include what type of source was used to charge the battery, the energy required to make the battery, and the energy expended in disposing of it, in an environmentally sound manner.
Recharging can take up to an hour, however this amount of time is being reduced as the technology improves. A major limiting factor is that currently (2017) there is inadequate recharging infrastructure for long routes, though many owners use home charging stations instead of commercial infrastructure. Battery cost limits range and increases purchase cost over IC vehicles, but battery costs are decreasing. Drivers can also sometimes suffer from range anxiety â€" the fear that the batteries will be depleted before reaching their destination. â€" though, in 2018, ranges over 160 km (100 mi) are typical of new models; and some makers (Tesla; General Motors) offer models with real-world ranges well over 320 km (200 mi), which is comparable to the range of a gasoline-fueled car.
As of December 2015, there were over 30 models of highway legal all-electric passenger cars and utility vans available. Cumulative global sales of highway-capable light-duty pure electric vehicles passed one million units in total, globally, in September 2016. The Nissan Leaf is the world's all-time best-selling highway-capable electric car in history, with over 300,000 units sold globally by January 2018. Ranking second is the Tesla Model S with almost 213,000 units sold worldwide through December 2017.
Terminology
Electric cars vs Petrol cars - Electric cars or internal combustion engine carsâ€"which is better? Electric cars were in their heyday back in 1900, but a sudden rise in petrol engine cars, accompanied by battery technology...
Electric cars are a variety of electric vehicle (EV). The term "electric vehicle" refers to any vehicle that uses electric motors for propulsion, while "electric car" generally refers to highway-capable automobiles powered by electricity. Low-speed electric vehicles, classified as neighborhood electric vehicles (NEVs) in the United States, and as electric motorised quadricycles in Europe, are plug-in electric-powered microcars or city cars with limitations in terms of weight, power and maximum speed that are allowed to travel on public roads and city streets up to a certain posted speed limit, which varies by country.
While an electric car's power source is not explicitly an on-board battery, electric cars with motors powered by other energy sources are generally referred to by a different name. An electric car carrying solar panels to power it is a solar car, and an electric car powered by a gasoline generator is a form of hybrid car. Thus, an electric car that derives its power from an on-board battery pack is a form of battery electric vehicle (BEV). Most often, the term "electric car" is used to refer to battery electric vehicles.
History
Thomas Parker built the first practical production electric car in London in 1884, using his own specially designed high-capacity rechargeable batteries. The Flocken Elektrowagen of 1888 was designed by German inventor Andreas Flocken. Electric cars were among the preferred methods for automobile propulsion in the late 19th century and early 20th century, providing a level of comfort and ease of operation that could not be achieved by the gasoline cars of the time. The electric vehicle stock peaked at approximately 30,000 vehicles at the turn of the 20th century.
In 1897, electric cars found their first commercial use in the USA. Based on the design of the Electrobat II, a fleet of twelve hansom cabs and one brougham were used in New York City as part of a project funded in part by the Electric Storage Battery Company of Philadelphia. During the 20th century, the main manufacturers of electric vehicles in the US were Anthony Electric, Baker, Columbia, Anderson, Edison, Riker, Milburn, Bailey Electric and others. Unlike gasoline-powered vehicles, the electric ones were less fast and less noisy, and did not require gear changes.
Advances in internal combustion engines in the first decade of the 20th century lessened the relative advantages of the electric car. The greater range of gasoline cars, and their much quicker refueling times, made them more popular and encouraged a rapid expansion of petroleum infrastructure, making gasoline easy to find, but what proved decisive was the introduction in 1912 of the electric starter motor which replaced other, often laborious, methods of starting the ICE, such as hand-cranking.
In the early 1990s, the California Air Resources Board (CARB) began a push for more fuel-efficient, lower-emissions vehicles, with the ultimate goal being a move to zero-emissions vehicles such as electric vehicles. In response, automakers developed electric models, including the Chrysler TEVan, Ford Ranger EV pickup truck,GM EV1, and S10 EV pickup, Honda EV Plus hatchback, Nissan Altra EV miniwagon, and Toyota RAV4 EV. Both US Electricar and Solectria produced 3-phase AC Geo-bodied electric cars with the support of GM, Hughes, and Delco. These early cars were eventually withdrawn from the U.S. market.
California electric automaker Tesla Motors began development in 2004 on what would become the Tesla Roadster (2008), which was first delivered to customers in 2008. The Roadster was the first highway legal serial production all-electric car to use lithium-ion battery cells, and the first production all-electric car to travel more than 320Â km (200 miles) per charge. Models released to the market between 2010 and December 2016 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, Hyundai Ioniq Electric and Chevrolet Bolt EV.
Cumulative global sales of the Nissan Leaf, currently the top selling electric car, passed 200,000 units in December 2015, five years after its introduction. The same month, the Renault-Nissan Alliance, the top selling all-electric vehicle manufacturer, passed the milestone of 300,000 electric vehicles sold worldwide. The Tesla Model 3 was unveiled on March 31, 2016 and more than 325,000 reservations were made during the first week since bookings opened, each customer paying a refundable US$1,000 deposit to reserve the car. Cumulative global sales of all-electric cars and vans passed the 1Â million unit milestone in September 2016. Global Tesla Model S sales achieved the 150,000 unit milestone in November 2016. Norway achieved the milestone of 100,000 all-electric vehicles registered in December 2016.
Tesla global sales passed 250,000 units in September 2017. The Renaultâ€"Nissanâ€"Mitsubishi Alliance achieved the milestone of 500,000 units electric vehicles sold in October 2017. Tesla sold its 200,000th Model S in the fourth quarter of 2017. Global Leaf sales passed 300,000 units in January 2018, keeping its record as the world's top selling plug-in electric car ever.
Economics
Purchase cost
As of 2013, electric cars are significantly more expensive than conventional internal combustion engine vehicles and hybrid electric vehicles due to the cost of their battery pack. However, battery prices are coming down about 8% per annum with mass production, and are expected to drop further as competition increases.
According to a 2010 survey, around three quarters of American and British car buyers have or would consider buying an electric car, but they are unwilling to pay more for an electric car. Several national and local governments have established tax credits, subsidies, and other incentives to reduce the net purchase price of electric cars and other plug-ins.
Car manufacturers choose different strategies for EVs. For low production, converting existing platforms is the cheapest as development cost is low. For higher production, a dedicated platform may be preferred to optimize design.
Almost 80% of electric vehicles in the U.S. are leased, while the lease rate for the country's entire fleet is about 30%. In early 2018, electric compact cars of 2014 are worth 23 percent of their original sticker price, as comparable cars with combustion engines worth 41 percent.
Battery first cost
Tesla Motors uses laptop-size cells for a cost of about $200 per kilowatt hour. Based on the three battery size options offered for the Tesla Model S, The New York Times estimated the cost of automotive battery packs between US$400 to US$500 per kilowatt-hour.
A 2013 study reported that battery costs came down from US$1,300 per kilowatt hour in 2007 to US$500 per kilowatt hour in 2012. The U.S. Department of Energy has set cost targets for its sponsored battery research of US$300 per kilowatt hour in 2015 and US$125 per kilowatt hour by 2022, and current solutions are on track to meet or exceed that goal. In 2017, General Motors was reported to be paying US$145 per kilowatt hour of battery capacity for the Bolt EV. As of January 2018, replacement Bolt battery packs have a list price from GM that is equivalent to US$262 per kilowatt hour. Further expected reductions of battery cost and higher production volumes will allow plug-in electric vehicles to be more competitive with conventional internal combustion engine vehicles.
A 2016 study by Bloomberg New Energy Finance (BNEF) says battery prices fell 65% since 2010, and 35% just in 2015, reaching US$350 per kWh. The study predicts electric car battery costs to be below US$120 per kWh by 2030, and to fall further thereafter as new chemistries become available. McKinsey estimates that electric cars are competitive at a battery pack cost of $100/kWh (around 2030), and expects pack costs to be $190/kWh by 2020.
Maintenance
The documentary Who Killed the Electric Car? shows a comparison between the parts that require replacement in gasoline-powered cars and EV1s, with the garages stating that they bring the electric cars in every 5,000Â mi (8,000Â km), rotate the tires, fill the windshield washer fluid and send them back out again. Other advantages of electric cars are that they do not need to be driven to petrol stations and there are often fewer fluids which need to be changed.
Electricity cost
The cost of charging the battery depends on the cost of electricity. As of November 2012, a Nissan Leaf driving 500 miles (800Â km) per week is estimated to cost US$600 per year in charging costs in Illinois, U.S., as compared to US$2,300 per year in fuel costs for an average new car using regular gasoline. Charging is more cost effective where cheaper off-peak electricity is available. For example, according to Nissan, the operating electricity cost of the Leaf in the UK is 1.75 pence per mile (1.09 p/km) when charging at an off-peak electricity rate, while a conventional petrol-powered car costs more than 10 pence per mile (6.21 p/km).
Battery depreciation
Much of the mileage-related cost of an electric vehicle is depreciation of the battery pack. To calculate the cost per kilometer of an electric vehicle it is therefore necessary to assign a monetary value to the wear incurred on the battery.
The Tesla Roadster's battery pack is expected to last seven years with typical driving and costs US$12,000 when pre-purchased today. Driving 40 miles (64Â km) per day for seven years or 102,200 miles (164,500Â km) leads to a battery consumption cost of US$0.1174 per 1 mile (1.6Â km) or US$4.70 per 40 miles (64Â km).
Total cost of ownership
A 2010 report, by J.D. Power and Associates states that it is not entirely clear to consumers the total cost of ownership of battery electric vehicles over the life of the vehicle, and "there is still much confusion about how long one would have to own such a vehicle to realize cost savings on fuel, compared with a vehicle powered by a conventional internal combustion engine (ICE). The resale value of HEVs and BEVs, as well as the cost of replacing depleted battery packs, are other financial considerations that weigh heavily on consumers' minds."
A 2011 study found that the gasoline costs savings of plug-in electric cars over their lifetimes do not offset their higher purchase prices.
The Chinese auto manufacturer BYD calculated on its website in 2015 that a BYD e6 taxi over five years would give a saving of about $74,000 over the equivalent petrol consumption.
In 2018 the Australian Federal Government’s advisory firm on vehicle emissions estimated the TCO for electric cars was 5 to 10 thousand dollars more per year than a roughly equivalent petrol powered car. Representatives of the electric car industry responded by claiming that more subsidies were necessary.
Dealership reluctance to sell
Almost all new cars in the United States are sold through dealerships, so they play a crucial role in the sales of electric vehicles, and negative attitudes can hinder early adoption of plug-in electric vehicles. Dealers decide which cars they want to stock, and a salesperson can have a big impact on how someone feels about a prospective purchase. Sales people have ample knowledge of internal combustion cars while they do not have time to learn about a technology that represents a fraction of overall sales. Retailers are central to ensuring that buyers have the information and support they need to gain the full benefits of adopting this new technology.
There are several reasons for the reluctance of some dealers to sell plug-in electric vehicles. PEVs do not offer car dealers the same profits as gasoline-powered car. Plug-in electric vehicles take more time to sell because of the explaining required, which hurts overall sales and sales people commissions. Electric vehicles also may require less maintenance, resulting in loss of service revenue, and thus undermining the biggest source of dealer profits, their service departments. According to the National Automobile Dealers Association (NADA), dealers on average make three times as much profit from service as they do from new car sales. However, a NADA spokesman said there was not sufficient data to prove that electric cars would require less maintenance. According to The New York Times, BMW and Nissan are among the companies whose dealers tend to be more enthusiastic and informed, but only about 10% of dealers are knowledgeable on the new technology.
A 2014 study found many car dealers are not enthusiastic about selling plug-in vehicles. Surveys of buyers of plug-in electric vehicles showed they were significantly less satisfied and rated the dealer purchase experience much lower than buyers of non-premium conventional cars. Plug-in buyers expect more from dealers than conventional buyers, including product knowledge and support that extends beyond traditional offerings. In 2014 Consumer Reports reported that not all sales people seemed enthusiastic about making PEV sales, and many seemed not to have a good understanding of electric-car incentives or of charging needs and costs. At 35 of the 85 dealerships visited, the secret shoppers said sales people recommended buying a gasoline-powered car instead.
The ITS-Davis study also found that a small but influential minority of dealers have introduced new approaches to better meet the needs of plug-in customers. Examples include marketing carpool lane stickers, enrolling buyers in charging networks, and preparing incentive paperwork for customers. Some dealers assign seasoned sales people as plug-in experts, many of whom drive plug-ins themselves to learn and be familiar with the technology and relate the car's benefits to potential buyers. The study concluded also that carmakers could do much more to support dealers selling PEVs.
Environmental aspects
Electric cars have several benefits over conventional internal combustion engine automobiles, including a significant reduction of local air pollution, especially in cities, as they do not emit harmful tailpipe pollutants such as particulates (soot), volatile organic compounds, hydrocarbons, carbon monoxide, ozone, lead, and various oxides of nitrogen. The clean air benefit may only be local because, depending on the source of the electricity used to recharge the batteries, air pollutant emissions may be shifted to the location of the generation plants. This is referred to as the long tailpipe of electric vehicles. The amount of carbon dioxide emitted depends on the emission intensity of the power sources used to charge the vehicle, the efficiency of the said vehicle and the energy wasted in the charging process. For mains electricity the emission intensity varies significantly per country and within a particular country, and on the demand, the availability of renewable sources and the efficiency of the fossil fuel-based generation used at a given time.
Electric cars usually also show significantly reduced greenhouse gas emissions, depending on the method used for electricity generation to charge the batteries. For example, some battery electric vehicles do not produce CO2 emissions at all, but only if their energy is obtained from sources such as solar, wind, nuclear, or hydropower.
Even when the power is generated using fossil fuels, electric vehicles usually, compared to gasoline vehicles, show significant reductions in overall well-wheel global carbon emissions due to the highly carbon-intensive production in mining, pumping, refining, transportation and the efficiencies obtained with gasoline.
Performance
Acceleration and drivetrain design
Electric motors can provide high power-to-weight ratios, and batteries can be designed to supply the large currents to support these motors. Electric motors have very flat torque curves down to zero speed. For simplicity and reliability, many electric cars use fixed-ratio gearboxes and have no clutch.
Although some electric vehicles have very small motors, 15Â kW (20Â hp) or less and therefore have modest acceleration, many electric cars have large motors and brisk acceleration. In addition, the relatively constant torque of an electric motor, even at very low speeds tends to increase the acceleration performance of an electric vehicle relative to that of the same rated motor power internal combustion engine.
Electric vehicles can also use a direct motor-to-wheel configuration which increases the amount of available power. Having multiple motors connected directly to the wheels allows for each of the wheels to be used for both propulsion and as braking systems, thereby increasing traction. When not fitted with an axle, differential, or transmission, electric vehicles have less drivetrain rotational inertia.
For example, the Venturi Fetish delivers supercar acceleration despite a relatively modest 220 kW (300 hp), and top speed of around 160 km/h (100 mph). Some DC-motor-equipped drag racer EVs have simple two-speed manual transmissions to improve top speed. The Tesla Roadster (2008) 2.5 Sport can accelerate from 0 to 97 km/h (0 to 60 mph) in 3.7 seconds with a motor rated at 215 kW (288 hp). Tesla Model S P100D (Performance / 100kWh / 4-wheel drive) is capable of 2.28 seconds for 0â€"60 mph at a price of $140,000 [1]. As of May 2017, the P100D is the second fastest production car ever built, slower by a mere 0.08 only to a $847,975 Porsche 918 Spyder. The Wrightspeed X1 prototype created by Wrightspeed Inc was in 2009 the worlds fastest street legal electric car to accelerate from 0 to 97 km/h (0 to 60 mph), which it does in 2.9 seconds. The electric supercar Rimac Concept One can go from 0â€"100 km/h (0â€"62 mph) in 2.8 seconds using 811 kW (1,088 hp).
Energy efficiency
Internal combustion engines have thermodynamic limits on efficiency, expressed as fraction of energy used to propel the vehicle compared to energy produced by burning fuel. Gasoline engines effectively use only 15% of the fuel energy content to move the vehicle or to power accessories, and diesel engines can reach on-board efficiency of 20%, while electric vehicles have on-board efficiency of over 90%, when counted against stored chemical energy, or around 80%, when counted against required energy to recharge.
Electric motors are more efficient than internal combustion engines in converting stored energy into driving a vehicle. Electric cars do not idle. Regenerative braking can recover as much as one fifth of the energy normally lost during braking.
Production and conversion electric cars typically use 10 to 23 kW·h/100 km (0.17 to 0.37 kW·h/mi). Approximately 20% of this power consumption is due to inefficiencies in charging the batteries. Tesla Motors indicates that the vehicle efficiency (including charging inefficiencies) of their lithium-ion battery powered vehicle is 12.7 kW·h/100 km (0.21 kW·h/mi) and the well-to-wheels efficiency (assuming the electricity is generated from natural gas) is 24.4 kW·h/100 km (0.39 kW·h/mi).
Cabin heating and cooling
Electric vehicles generate very little waste heat. Supplemental heat may have to be used to heat the interior of the vehicle if heat generated from battery charging/discharging cannot be used to heat the interior. While heating can be provided with an electric resistance heater, higher efficiency and integral cooling can be obtained with a reversible heat pump. Positive Temperature Coefficient (PTC) junction cooling is also attractive for its simplicity â€" this kind of system is used for example in the Tesla Roadster (2008).
To avoid draining the battery and thus reducing the range, some models allow the cabin to be heated while the car is plugged in. For example, the Nissan Leaf, the Mitsubishi i-MiEV and the Tesla Model S can be pre-heated while the vehicle is plugged in.
Some electric cars, for example the Citroën Berlingo Electrique, use an auxiliary heating system (for example gasoline-fueled units manufactured by Webasto or Eberspächer) but sacrifice "green" and "Zero emissions" credentials. Cabin cooling can be augmented with solar power, or by automatically allowing outside air to flow through the car when parked. Two models of the 2010 Toyota Prius include this feature as an option.
Safety
The safety issues of BEVs are largely dealt with by the international standard ISO 6469. This document is divided in three parts dealing with specific issues:
- On-board electrical energy storage, i.e. the battery
- Functional safety means and protection against failures
- Protection of persons against electrical hazards.
Risk of fire
Lithium-ion batteries may suffer thermal runaway and cell rupture if overheated or overcharged, and in extreme cases this can lead to combustion. Several plug-in electric vehicle fire incidents have taken place since the introduction of mass-production plug-in electric vehicles in 2008. Most of them have been thermal runaway incidents related to their lithium-ion battery packs, and have involved the Zotye M300 EV, Chevrolet Volt, Fisker Karma, BYD e6, Dodge Ram 1500 Plug-in Hybrid, Toyota Prius Plug-in Hybrid, Mitsubishi i-MiEV and Outlander P-HEV. As of November 2013, four post-crash fires associated with the batteries of all-electric carsâ€"involving one BYD e6 and three Tesla Model S carsâ€"have been reported.
The first modern crash-related fire was reported in China in May 2012, after a high-speed car crashed into a BYD e6 taxi in Shenzhen. The second reported incident occurred in the United States on October 1, 2013, when a Tesla Model S caught fire over ten minutes after the electric car hit metal debris on a highway in Kent, Washington state, and the debris punctured one of 16 modules within the battery pack. A second reported fire occurred on October 18, 2013 in Merida, Mexico. In this case the vehicle was being driven at high speed through a roundabout and crashed through a wall and into a tree. The fire broke out many minutes after the driver exited the vehicle. On November 6, 2013, a Tesla Model S being driven on Interstate 24 near Murfreesboro, Tennessee caught fire after it struck a tow hitch on the roadway, causing damage beneath the vehicle.
In the United States, General Motors ran in several cities a training program for firefighters and first responders to demonstrate the sequence of tasks required to safely disable the Chevrolet Volt’s powertrain and its 12 volt electrical system, which controls its high-voltage components, and then proceed to extricate injured occupants. The Volt's high-voltage system is designed to shut down automatically in the event of an airbag deployment, and to detect a loss of communication from an airbag control module. GM also made available an Emergency Response Guide for the 2011 Volt for use by emergency responders. The guide also describes methods of disabling the high voltage system and identifies cut zone information. Nissan also published a guide for first responders that details procedures for handling a damaged 2011 Leaf at the scene of an accident, including a manual high-voltage system shutdown, rather than the automatic process built-in the car's safety systems.
Vehicle safety
Great effort is taken to keep the mass of an electric vehicle as low as possible to improve its range and endurance. However, the weight and bulk of the batteries themselves usually makes an EV heavier than a comparable gasoline vehicle, reducing range and leading to longer braking distances. However, in a collision, the occupants of a heavy vehicle will, on average, suffer fewer and less serious injuries than the occupants of a lighter vehicle; therefore, the additional weight brings safety benefits despite having a negative effect on the car's performance. They also use up interior space if packaged ineffectively. If stored under the passenger cell, not only is this not the case, they also lower the vehicles's center of gravity, increasing driving stability, thereby lowering the risk of an accident through loss of control. An accident in a 2,000Â lb (900Â kg) vehicle will on average cause about 50% more injuries to its occupants than a 3,000Â lb (1,400Â kg) vehicle. In a single car accident, and for the other car in a two car accident, the increased mass causes an increase in accelerations and hence an increase in the severity of the accident.
Some electric cars use low rolling resistance tires, which typically offer less grip than normal tires. Many electric cars have a small, light and fragile body, though, and therefore offer inadequate safety protection. The Insurance Institute for Highway Safety in America had condemned the use of low speed vehicles and "mini trucks," referred to as neighborhood electric vehicles (NEVs) when powered by electric motors, on public roads. Mindful of this, several companies (Tesla Motors, BMW, Uniti) have succeeded in keeping the body light, while making it very strong.
Hazard to pedestrians
At low speeds, electric cars produced less roadway noise as compared to vehicles propelled by internal combustion engines. Blind people or the visually impaired consider the noise of combustion engines a helpful aid while crossing streets, hence electric cars and hybrids could pose an unexpected hazard. Tests have shown that this is a valid concern, as vehicles operating in electric mode can be particularly hard to hear below 20Â mph (30Â km/h) for all types of road users and not only the visually impaired. At higher speeds, the sound created by tire friction and the air displaced by the vehicle start to make sufficient audible noise.
The Government of Japan, the U.S. Congress, and the European Parliament passed legislation to regulate the minimum level of sound for hybrids and plug-in electric vehicles when operating in electric mode, so that blind people and other pedestrians and cyclists can hear them coming and detect from which direction they are approaching. The Nissan Leaf was the first electric car to use Nissan's Vehicle Sound for Pedestrians system, which includes one sound for forward motion and another for reverse. As of January 2014, most of the hybrids and plug-in electric and hybrids available in the United States, Japan and Europe make warning noises using a speaker system. The Tesla Model S is one of the few electric cars without warning sounds, because Tesla Motors will wait until regulations are enacted. Volkswagen and BMW also decided to add artificial sounds to their electric drive cars only when required by regulation.
Several anti-noise and electric car advocates have opposed the introduction of artificial sounds as warning for pedestrians, as they argue that the proposed system will only increase noise pollution.. Added to this, such an introduction is based on vehicle type and not actual noise level, a concern regarding ICE vehicles which themselves are becoming quieter.
Electrical interference
On-board electrical systems generate enough interference that some manufacturers have removed AM radios from their vehicles due to poor reception.
Controls
Presently most EV manufacturers do their best to emulate the driving experience as closely as possible to that of a car with a conventional automatic transmission that motorists in some countries are familiar with. Most models therefore have a PRNDL selector traditionally found in cars with automatic transmission despite the underlying mechanical differences. Push buttons are the easiest to implement as all modes are implemented through software on the vehicle's controller.
Even though the motor may be permanently connected to the wheels through a fixed-ratio gear and no parking pawl may be present the modes "P" and "N" will still be provided on the selector. In this case the motor is disabled in "N" and an electrically actuated hand brake provides the "P" mode.
In some cars the motor will spin slowly to provide a small amount of creep in "D", similar to a traditional automatic.
When the foot is lifted from the accelerator of an ICE, engine braking causes the car to slow. An EV would coast under these conditions, but applying mild regenerative braking instead provides a more familiar response and recharges the battery somewhat. Selecting the L mode will increase this effect for sustained downhill driving, analogous to selecting a lower gear. These features also reduce the use of the conventional brakes, significantly reducing wear and tear and maintenance costs as well as improving vehicle range.
Batteries
While most current highway-speed electric vehicle designs focus on lithium-ion and other lithium-based variants a variety of alternative batteries can also be used. Lithium-based batteries are often chosen for their high power and energy density but have a limited shelf life and cycle lifetime which can significantly increase the running costs of the vehicle. Variants such as Lithium iron phosphate and Lithium-titanate attempt to solve the durability issues of traditional lithium-ion batteries.
Other battery types include lead acid batteries which are still the most used form of power for most of the electric vehicles used today. The initial construction costs are significantly lower than for other battery types, but the power to weight ratio is poorer than other designs, Nickel metal hydride (NiMH) which are somewhat heavier and less efficient than lithium ion, but also cheaper. Several other battery chemistries are in development such as zinc-air battery which could be much lighter, and liquid batteries that might be rapidly refilled, rather than recharged, are also under development.
Range
The range of an electric car depends on the number and type of batteries used. The weight and type of vehicle, and the performance demands of the driver, also have an impact just as they do on the range of traditional vehicles. Range may also significantly be reduced in cold weather.
The range of current production electric vehicles ranges anywhere from 80Â km (Renault Twizy) to 500Â km (Rimac Concept One).
Electric cars are virtually universally fitted with an expected range display. This may take into account many factors, including battery charge, the recent average power use, the ambient temperature, driving style, air conditioning system, route topography etc. to come up with an estimated driving range. However, since factors can vary over the route, the estimate can vary from the actual achieved range. People can thus be concerned that they would run out of energy from their battery before reaching their destination, a worry known as range anxiety. The display allows the driver able to make informed choices about driving speed and whether to, perhaps briefly, stop at a charging point en route to ensure that they have enough charge that they arrive at their destination successfully. Some roadside assistance organizations offer charge trucks to reload empty electric cars.
A study in 2016 stated that 87% of US vehicle-days can be met by current affordable electric cars.
Charging
Electric cars typically have less maximum range on one charge than do fossil fueled cars, and can take considerable time to recharge. However, they can be charged at home overnight, which fossil fueled cars cannot. 71% of all car drivers in America drive less than 40 miles (64Â km) per day, and require only a relatively quick topping up.
In the United States, most commercially-sold models of electric car use a single standardized plug interface, SAE J1772, which includes provision for direct communication between the car's electronics and external charging equipment. Other regions (notably Europe and China) have adopted similar charging standards albeit with different plug interfaces. This means that, within each major region of the world, electric car charging stations are essentially universal across car and charger brands, and simply plugging in a charger into an electric car will charge the car at the fastest rate that both car and charger can support. A notable exception are the Tesla line of cars, which use a proprietary charging standard that is electrically similar to SAE J1772 but uses a different physical plug; Tesla cars can use standard charging equipment but require an adapter to do so.
Although batteries work with D.C. electricity, cars with the SAE J1772 and similar charging inlets can accept A.C. electricity directly from a local electrical grid. Standards exist for very rapid D.C. charging as well. In rapid D.C. chargers, A.C. grid electricity is converted to direct current in the charging station, avoiding the need for the car to carry heavy and expensive very-high-power charging circuits.
Home charging
As examples of on-board chargers, the Nissan Leaf at launch had a 3.3Â kW charger, and the Tesla Roadster can accept up to 16.8Â kW (240Â V at 70Â A) from the High Power Wall Connector.
Rapid charging
However, most vehicles also support much faster charging, where a suitable power supply is available. Therefore, for long distance travel, in the US and elsewhere, there has been the installation of Fast Charging stations with high-speed charging capability from three-phase industrial outlets so that consumers can recharge the battery of their electric vehicle to 80 percent in about 30 minutes (for example Nissan Leaf, Tesla Model S, Renault Zoe, BMW i3 etc.). Although charging at these stations is still relatively time consuming compared to refueling, in practice it often meshes well with a normal driving pattern, where driving is usually done for a few hours before stopping and resting and drinking or eating; this gives the car a chance to be charged.
As of December 2013, Estonia is the first and only country that had deployed an EV charging network with nationwide coverage, with fast chargers available along highways at a minimum distance of between 40 to 60 km (25 to 37 mi), and a higher density in urban areas. DC Fast Chargers are going to be installed at 45 BP and ARCO locations and will be made available to the public as early as March 2011. The EV Project will deploy charge infrastructure in 16 cities and major metropolitan areas in six states. Nissan has announced that 200 of its dealers in Japan will install fast chargers for the December 2010 launch of its Leaf EV, with the goal of having fast chargers everywhere in Japan within a 25-mile radius.
Charging time
Electric cars generally require more time to "refuel" via electric charging, than do internal-combustion cars. The time varies greatly depending on the charging technology, and principally depends on the amount of electric power available at the charger. Charging times can vary from minutes to days for the same car, depending on the capacity of the charging equipment being used.
Many electric cars can be recharged to 80 percent in about 30 minutes (for example Nissan Leaf, Tesla Model S, Renault Zoe, BMW i3 etc.), using DC rapid-charging technology. At least three major standards exist for this technology: SAE Combo (based on SAE J1772), CHAdeMO (the major standard in Japan and also widely used in the U.S.), and Tesla Supercharger. The first two are attempts at a universal standard high-speed plug; Tesla model cars use a proprietary standard that is not directly compatible with the others.
The Porsche Mission E will be able to charge to 80 percent within 15 minutes, making it the fastest-charging electric vehicle available. According to Tesla, the Tesla Model S and Tesla Model X can be charged from a proprietary DC quick-charging station that provides up to 135Â kW of power, giving 85Â kWh vehicles 290Â km (180Â mi) of range in about 30 minutes.
According to the manufacturer BYD the lithium iron phosphate battery of the electric car e6 is charged at a fast charging station within 15 minutes to 80%, after 40 minutes at 100%.
Instead of giving the charging rate in kilowatts, the charge speed is sometimes expressed as "miles range per hour" (mrph), as it may be easier to understand, and cars have different consumption.
Battery swapping
Another way to extend the limited range of electric vehicles is by battery swapping. An EV can go to a battery switch station and swap a depleted battery with a fully charged one in a few minutes. In 2011, Better Place deployed the first modern commercial application of the battery switching model, but due to financial difficulties, the company filed for bankruptcy in May 2013.
Tesla Motors designed its Model S to allow fast battery swapping. In June 2013, Tesla announced their goal to deploy a battery swapping station in each of its supercharging stations. At a demonstration event Tesla showed that a battery swap operation with the Model S takes just over 90 seconds, about half the time it takes to refill a gasoline-powered car. The first stations are planned to be deployed along Interstate 5 in California where, according to Tesla, a large number of Model S sedans make the San Francisco-Los Angeles trip regularly. These will be followed by the Washington, DC to Boston corridor. Each swapping station will cost US$500,000 and will have about 50 batteries available without requiring reservations. The service would be offered for the price of about 15 US gallons (57 l; 12 imp gal) of gasoline at the current local rate, around US$60 to US$80 at June 2013 prices.
Range extension
A similar idea is that of the range-extension trailer which is attached only when going on long trips. The trailers can either be owned or rented only when necessary.
BMW i is offering a built-in gasoline-powered range extender engine as an option for its BMW i3 all-electric car. The range-extender option will cost an additional US$3,850 in the United States, an additional €4,710 (~ US$6,300) in France, and €4,490 (~ US$6,000) in the Netherlands.
Lifespan
Battery life should be considered when calculating the extended cost of ownership, as all batteries eventually wear out and must be replaced. The rate at which they expire depends on the type of battery and how they are used â€" many types of batteries are damaged by depleting them beyond a certain level. Lithium-ion batteries degrade faster when stored at higher temperatures, when they are rapidly charged, and when they are fully charged. Many users set their cars to charge to 80% for their daily charging; which is usually enough for daily mileage, only charging them to 100% for longer journeys.
Although there are times when batteries do fail the electric vehicles' batteries are designed to last for the expected life of the vehicle. The failure rate of some electric vehicles batteries already on the road is as low as 0.003%. There are also high mileage warranties on electric vehicle batteries. Several manufactures offer up to eight year and one hundred thousand mile warranties on the batteries alone.
A full replacement battery is relatively costly. With technological advances there are now recycle options available ("Maintenance and Safety of Electric Vehicles"), and a battery that is no longer capable of delivering sufficient range nevertheless has significant trade-in value.
Nissan stated in 2015 that thus far only 0.01 percent of batteries had to be replaced because of failures or problems and then only because of externally inflicted damage. There are few vehicles that have already covered more than 200,000Â km (124,274Â mi) anyway. These have no problems with the battery.
Future
- Lithium availability
Many electric cars use a lithium-ion battery and an electric motor which uses rare-earth elements. The demand for lithium, heavy metals, and other specific elements (such as neodymium, boron and cobalt) required for the batteries and powertrain is expected to grow significantly due to the future sales increase of plug-in electric vehicles in the mid and long term. Some of the largest world reserves of lithium and other rare metals are located in countries with strong resource nationalism, unstable governments or hostility to U.S. interests, raising concerns about the risk of replacing dependence on foreign oil with a new dependence on hostile countries to supply strategic materials. It is estimated that there are sufficient lithium reserves to power 4 billion electric cars.
- Other methods of energy storage
Experimental supercapacitors and flywheel energy storage devices offer comparable storage capacity, faster charging, and lower volatility. They have the potential to overtake batteries as the preferred rechargeable storage for EVs. The FIA included their use in its sporting regulations of energy systems for Formula One race vehicles in 2007 (for supercapacitors) and 2009 (for flywheel energy storage devices).
- Solar cars
Solar cars are electric vehicles powered completely or significantly by direct solar energy, usually, through photovoltaic (PV) cells contained in solar panels that convert the sun's energy directly into electric energy.
- Electrified Road
In March 2016 Toyohashi University of Technology and Taisei Corp of Japan unveiled the first electrical car in the world that would be able to run without a battery. The electric car receives its charge from an electrified road. The test was made on electrified road in Toyohashi, in the Aichi Prefecture.
Infrastructure
Charging station
Batteries in BEVs must be periodically recharged (see also Replacing, above). Unlike vehicles powered directly by fossil fuels, BEVs are most commonly and conveniently charged from the power grid overnight at home, without the inconvenience of having to go to a filling station. Charging can also be done using a street, garage or shop charging station. The electricity on the grid is in turn generated from a variety of sources; such as coal, hydroelectricity, nuclear and others. Power sources such as photovoltaic solar cell panels, micro hydro or wind may also be used and are promoted because of concerns regarding global warming.
More electrical power to the car reduces charging time. Power is limited by the capacity of the grid connection, and, for level 1 and 2 charging, by the power rating of the car's on-board charger. A normal household outlet is between 1.5 kW (in the US, Canada, Japan, and other countries with 110 volt supply) to 3 kW (in countries with 230 V supply). The main connection to a house may sustain 10, 15 or even 20 kW in addition to "normal" domestic loadsâ€"although, it would be unwise to use all the apparent capabilityâ€"and special wiring can be installed to use this.
As part of its commitment to environmental sustainability, the Dutch government initiated a plan to establish over 200 recharging stations for electric vehicles across the country by 2015. The rollout was undertaken by Switzerland-based power and automation company ABB and Dutch startup Fastned, and aims to provide at least one station every 50 kilometres (31 miles) for the Netherlands' 16 million residents.
There are several types of charging machines. The Japanese-developed CHAdeMO standard is favored by Nissan, Mitsubishi, and Toyota, while the Society of Automotive Engineers’ (SAE) International J1772 Combo standard is backed by GM, Ford, Volkswagen, and BMW. Both are direct-current quick-charging systems designed to charge the battery of an electric vehicle to 80 percent in approximately 20 minutes, but the two systems are incompatible. Unless the two companies cooperate, experts have warned that the momentum of the electric vehicle market will be restricted. Richard Martin, editorial director for clean technology marketing and consultant firm Navigant Research, stated:
Fast charging, however and whenever it gets built out, is going to be key for the development of a mainstream market for plug-in electric vehicles. The broader conflict between the CHAdeMO and SAE Combo connectors, we see that as a hindrance to the market over the next several years that needs to be worked out.
Research continues on ways of reducing the charging times for electric cars. The BMW i3 for example, can charge 0â€"80% of the battery in under 30 minutes in rapid charging mode. The superchargers developed by Tesla Motors provided up to 130 kW of charging, allowing a 50% charge in 20 minutes. Considering the size of the battery, that translated to approx. 212 km of range.
US charging standards
Around 1998 the California Air Resources Board classified levels of charging power that have been codified in title 13 of the California Code of Regulations, the U.S. 1999 National Electrical Code section 625 and SAE International standards. Four standards were developed, termed AC Level 1, AC Level 2, AC Level 3 charging, and Combo Charging System (CCS).
- * or potentially 208 V × 37 A, out of the strict specification but within circuit breaker and connector/cable power limits. Alternatively, this voltage would impose a lower power rating of 6.7 kW at 32 A.
More recently the term "Level 3" has also been used by the SAE J1772 Standard Committee for a possible future higher-power AC fast charging standard. To distinguish from Level 3 DC fast charging, this would-be standard is written as "Level 3 AC". SAE has not yet approved standards for either AC or DC Level 3 charging.
As of June 2012, some electric cars provide charging options that do not fit within the older California "Level 1, 2, and 3 charging" standard, with its top charging rate of 40 A. For example, the Tesla Roadster may be charged at a rate up to 70 A (16.8 kW) with a wall-mounted charger.
For comparison, in Europe the IEC 61851-1 charging modes are used to classify charging equipment. The provisions of IEC 62196 charging modes for conductive charging of electric vehicles include Mode 1 (max. 16Â A / max. 250Â V AC. or 480Â V three-phase), Mode 2 (max. 32Â A / max. 250Â V AC or 480Â V three-phase), Mode 3 (max. 63Â A (70Â A U.S.) / max. 690Â V AC or three-phase) and Mode 4 (max. 400Â A / max. 600Â V DC).
Connectors
Most electric cars have used conductive coupling to supply electricity for recharging after the California Air Resources Board settled on the SAE J1772-2001 standard as the charging interface for electric vehicles in California in June 2001. In Europe, the ACEA has decided to use the Type 2 connector from the range of IEC_62196 plug types for conductive charging of electric vehicles in the European Union as the Type 1 connector (SAE J1772-2009) does not provide for three-phase charging.
Another approach is inductive charging using a non-conducting "paddle" inserted into a slot in the car. Delco Electronics developed the Magne Charge inductive charging system around 1998 for the General Motors EV1 and it was also used for the Chevrolet S-10 EV and Toyota RAV4 EV vehicles.
Vehicle-to-grid: uploading and grid buffering
During peak load periods, when the cost of generation can be very high, electric vehicles could contribute energy to the grid. These vehicles can then be recharged during off-peak hours at cheaper rates while helping to absorb excess night time generation. Here the batteries in the vehicles serve as a distributed storage system to buffer power.
Politics
Electric vehicles provide for less dependence on foreign oil, which for the United States and other developed or emerging countries is cause for concern about vulnerability to oil price volatility and supply disruption. Also for many developing countries, and particularly for the poorest in Africa, high oil prices have an adverse impact on their balance of payments, hindering their economic growth. In the United States, presidential candidate Obama proposed in 2008 "1 million plug-in and electric" cars by 2015. At the end of 2015 about 550 thousand plugin-in vehicles had been sold in the USA.
Currently available electric cars
Highway capable
As of December 2015, there were over 30 models of highway-capable all-electric passenger cars and utility vans available in the market for retail sales. The global stock of light-duty all-electric vehicles totaled 739,810 units, out of a global stock of 1.257 million light-duty plug-in electric vehicles on the road at the end of 2015. The global ratio between all-electrics (BEVs) and plug-in hybrids (PHEVs) has consistently been 60:40 between 2014 and the first half of 2016, mainly due to the large all-electric market in China. In the U.S. and Europe, the ratio is approaching a 50:50 split. Cumulative global sales of all-electric cars and vans passed the 1 million unit milestone in September 2016.
The Renaultâ€"Nissanâ€"Mitsubishi Alliance is the world's leading all-electric vehicle manufacturer. The Alliance reached sales of 500,000 all-electric vehicles delivered globally in October 2017, including those manufactured by Mitsubishi Motors, now part of the Alliance. The Alliance, including Mitsubishi Motors i-Miev series, sold globally 94,265 all-electric vehicles in 2016. Nissan global electric vehicle sales passed 275,000 units in December 2016. The Nissan Leaf was the world's top selling plug-in car in 2013 and 2014. Renault global electric vehicle sales passed the 100,000 unit milestone in September 2016. In December 2014, Nissan announced that Leaf owners have accumulated together 1 billion kilometers (620 million miles) driven. This amount of electric miles translates into saving 180 million kilograms of CO2 emissions by driving an electric car in comparison to travelling with a gasoline-powered car. In December 2016, Nissan reported that Leaf owners worldwide achieved the milestone of 3 billion kilometers (1.9 billion miles) driven collectively through November 2016.
As of September 2017, Tesla, Inc. ranked as the all-time second best-selling all-electric vehicle manufacturer with more than 250,000 electric cars worldwide since delivery of its first Tesla Roadster in 2008. Its Model S was the world's best selling plug-in electric car for two years in a row, 2015 and 2016. In early October 2016, Tesla reported that combined miles driven by its three models have accumulated 3 billion electric miles (4.8 billion km) traveled. The first billion mark was recorded in June 2015 and the second billion in April 2016. BMW is the third best selling all-electric vehicle manufacturer with more than 65,000 i3s sold through December 2016, including the REx variant.
The world's all-time top selling highway legal electric car is the Nissan Leaf, released in December 2010, with global sales of more than 300,000 units through January 2018. The Tesla Model S ranks second with global sales of 212,874 cars delivered as of December 2017. The Renault Kangoo Z.E. utility van is the leader of the light-duty all-electric segment with global sales of 25,205 units through December 2016. The following table list the best-selling highway-capable all-electric cars with cumulative global sales of around or more than 20,000 units since their inception through December 2016:
Electric cars by country
As of December 2016, more than two million highway legal plug-in electric passenger cars and light utility vehicles (PEVs) have been sold worldwide. The stock of plug-in electric cars represented 0.15% of the 1.4 billion motor vehicles on the world's roads by the end of 2016, up from 0.1% in 2015. The three million milestone was achieved in November 2017.
Sales of plug-in electric vehicles achieved the one million milestone in September 2015, almost twice as fast as hybrid electric vehicles (HEV). While it took four years and 10 months for the PEV segment to reach one-million sales, it took more than around nine years and a few months for HEVs to reach its first million sales. Cumulative global sales of highway-capable light-duty pure electric vehicles passed one million units in total, globally, in September 2016. When global sales are broken down by type of powertrain, all-electric cars have oversold plug-in hybrids, with pure electrics capturing 61% of the global stock of two million light-duty plug-ins on the world's roads by the end of 2016.
Government subsidy
Several countries have established grants and tax credits for the purchase of new electric cars depending on battery size. The U.S. offers a federal income tax credit up to US$7,500, and several states have additional incentives. The UK offers a Plug-in Car Grant up to a maximum of GB£4,500 (US$5,929). The U.S. government also pledged US$2.4 billion in federal grants for the development of advanced technologies for electric cars and batteries, despite the fact that overall sales aren't increasing at the expected speed.
As of April 2011, 15 European Union member states provide economic incentives for the purchase of new electrically chargeable vehicles, which consist of tax reductions and exemptions, as well as of bonus payments for buyers of all-electric and plug-in hybrid vehicles, hybrid electric vehicles, and some alternative fuel vehicles.
See also
- Battery electric vehicle
- Electric boat
- Electric bus
- Electric car energy efficiency
- Electric motorcycles and scooters
- Electric motorsport
- Electric vehicle
- Electric vehicle conversion
- Plug-in electric vehicle
References
External links
- How an electric car works