Electric car
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See also: Electric vehicle and Battery electric vehicle
The Nissan Leaf goes on sale at the end of 2010 in select markets, with global availability scheduled for 2012.[1]
Sales of the Mitsubishi i MiEV to the public began in Japan in April 2010 and in Hong Kong in May 2010.[2]
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An electric car is an automobile that uses an electric motor for propulsion, in place of more common propulsion methods such as the internal combustion engine (ICE).
Electric cars are usually powered by on-board battery packs, and as such are usually battery electric vehicles (BEVs). Although electric cars often give good acceleration and have generally acceptable top speed, the poorer energy capacity of batteries compared to that of fossil fuels means that electric cars have relatively poor range between charges, and recharging can take significant lengths of time. However, for everyday use, rather than long journeys, electric cars are very practical forms of transportation and can be inexpensively recharged overnight. Other on-board energy storage methods that may give more range or faster recharge are areas of research.
Electric cars have the potential of significantly reducing city pollution by having zero tail pipe emissions.[3][4][5] Vehicle greenhouse gas savings depend on how the electricity is generated. With the current U.S. energy mix, using an electric car would result in a 30% reduction in carbon dioxide emissions.[6][7][8][9] Given the current energy mixes in other countries, it has been predicted that such emissions would decrease by 40% in the UK[10], 19% in China[11], and as little as 1% in Germany.[12][13]
Electric cars are expected to have a major impact in the auto industry[14][15] given advantages in city pollution, less dependence on oil, and expected rise in gasoline prices.[16][17][18]
Etymology
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 road-going automobiles powered by electricity. 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 powered by sunlight 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 called a battery electric vehicle (BEV). Most often, the term "electric car" is used to refer to pure battery electric vehicles, such as the REVAi and GM EV1.
[edit] History
German electric car, 1904, with the chauffeur on topMain article: History of the electric vehicle
Electric cars enjoyed popularity between the mid-19th century and early 20th century, when electricity was among the preferred methods for automobile propulsion, providing a level of comfort and ease of operation that could not be achieved by the gasoline cars of the time. Advances in ICE technology soon rendered this advantage moot; the greater range of gasoline cars, quicker refueling times, and growing petroleum infrastructure, along with the mass production of gasoline vehicles by companies such as the Ford Motor Company, which reduced prices of gasoline cars to less than half that of equivalent electric cars, led to a decline in the use of electric propulsion, effectively removing it from important markets such as the United States by the 1930s. However, in recent years, increased concerns over the environmental impact of gasoline cars, along with reduced consumer ability to pay for fuel for gasoline cars, and the prospect of peak oil, has brought about renewed interest in electric cars, which are perceived to be more environmentally friendly and cheaper to maintain and run, despite high initial costs. Electric cars currently enjoy relative popularity in countries around the world, though they are notably absent from the roads of the United States, where electric cars briefly re-appeared in the late 90s as a response to changing government regulations.
1912 Detroit Electric advertisement[edit] 1830s to 1900s: Early history
Before the pre-eminence of internal combustion engines, electric automobiles held many speed and distance records. Among the most notable of these records was the breaking of the 100 km/h (62 mph) speed barrier, by Camille Jenatzy on April 29, 1899 in his 'rocket-shaped' vehicle Jamais Contente, which reached a top speed of 105.88 km/h (65.79 mph). Before the 1920s, electric automobiles were competing with petroleum-fueled cars for urban use of a quality service car.[19]
Thomas Edison and an electric car in 1913 (courtesy of the National Museum of American History)In 1897, electric vehicles found their first commercial application in the U.S. as a fleet of electrical New York City taxis, built by the Electric Carriage and Wagon Company of Philadelphia. Electric cars were produced in the US by Anthony Electric, Baker, Columbia, Anderson, Edison [disambiguation needed], Studebaker, Riker, Milburn, and others during the early 20th century.
The low range of electric cars meant they could not make use of the new highways to travel between citiesDespite their relatively slow speed, electric vehicles had a number of advantages over their early-1900s competitors. They did not have the vibration, smell, and noise associated with gasoline cars. They did not require gear changes, which for gasoline cars was the most difficult part of driving. Electric cars found popularity among well-heeled customers who used them as city cars, where their limited range proved to be even less of a disadvantage. The cars were also preferred because they did not require a manual effort to start, as did gasoline cars which featured a hand crank to start the engine. Electric cars were often marketed as suitable vehicles for women drivers due to this ease of operation.
The Henney Kilowatt, a 1961 production electric carIn 1911, the New York Times stated that the electric car has long been recognized as "ideal" because it was cleaner, quieter and much more economical than gasoline-powered cars. Reporting this in 2010, the Washington Post commented that "the same unreliabilty of electric car batteries that flummoxed Thomas Edison persists today."[20]
Acceptance of electric cars was initially hampered by a lack of power infrastructure, but by 1912, many homes were wired for electricity, enabling a surge in the popularity of the cars. At the turn of the century, 40 percent of American automobiles were powered by steam, 38 percent by electricity, and 22 percent by gasoline. 33,842 electric cars were registered in the United States, and America became the country where electric cars had gained the most acceptance. Sales of electric cars peaked in 1912.
In 1917, the first gasoline-electric hybrid car was released by the Woods Motor Vehicle Company of Chicago. The hybrid was a commercial failure, proving to be too slow for its price, and too difficult to service.
[edit] 1990s to present: Revival of mass interest
The General Motors EV1, one of the cars introduced as a result of the California Air Resources Board (CARB) mandate, had a range of 160 mi (260 km) with NiMH batteries in 1999At the 1990 Los Angeles Auto Show, General Motors President Roger Smith unveiled the GM Impact electric concept car, along with the announcement that GM would build electric cars for sale to the public.
In the early 1990s, the California Air Resources Board (CARB), the government of California's "clean air agency", 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 2000, Hybrid Technologies, later Li-ion Motors, started manufacturing electric cars in Mooresville, North Carolina. California electric car maker Tesla Motors began development in 2004 on the Tesla Roadster, which was first delivered to customers in 2008. The Roadster remains the only highway-capable EV in serial production and available for sale today. Senior leaders at several large automakers, including Nissan and General Motors, have stated that the Roadster was a catalyst which demonstrated that there is pent-up consumer demand for more efficient vehicles. GM Vice Chairman Bob Lutz said in 2007 that the Tesla Roadster inspired him to push GM to develop the Chevrolet Volt, a plug-in hybrid sedan prototype that aims to reverse years of dwindling market share and massive financial losses for America's largest automaker.[21] In an August 2009 edition of The New Yorker, Lutz was quoted as saying, "All the geniuses here at General Motors kept saying lithium-ion technology is 10 years away, and Toyota agreed with us -- and boom, along comes Tesla. So I said, 'How come some tiny little California startup, run by guys who know nothing about the car business, can do this, and we can't?' That was the crowbar that helped break up the log jam."[22]
The Nissan LEAF, due to be launched in 2010,[23] is expected to be the first all electric, zero emission five door family hatchback to be produced for the mass market. Lithium-ion battery technology, smooth body shell and advanced regenerative braking give the LEAF performance comparable to an ICE, a range of around 160 km and the capability to reach 80% recharge levels in under 30 minutes.[24] In June 2009 BMW began field testing in the U.S. of its all-electric Mini E,[25] through the leasing of 500 cars to private users in Los Angeles and the New York/New Jersey area.[26][27] A similar field test was launched in the U.K. in December 2009 with a fleet of more than forty Mini E cars.[28]
[edit] Comparison with internal combustion engine vehicles
The Toyota RAV4 EV is powered by twenty-four 12 volt batteries, with an operational cost equivalent of over 165 mpg-US (1.43 L/100 km; 198 mpg-imp) at 2005 US gasoline prices.An important goal for electric vehicles is overcoming the disparity between their costs of development, production, and operation, with respect to those of equivalent internal combustion engine vehicles (ICEVs).
[edit] Running costs
"Fuel" cost comparison: the Tesla Roadster sport car's plug-to-wheel energy use is 280 W·h/mi. In Northern California, the local electric utility company PG&E says that "The E-9 rate is mandatory for those customers that are currently on a residential electric rate and who plan on refueling an EV on their premises."[29] Combining these two facts implies that driving a Tesla Roadster 40 miles (64 km) a day would use 11.2 kW·h of electricity costing between US$0.56 and US$3.18 depending on the time of day chosen for recharging.[29] For comparison, driving an internal combustion engine-powered car the same 40 miles (64 km), at a mileage of 25 mpg[clarification needed], would use 1.6 US gallons (6.1 l; 1.3 imp gal) of fuel and, at a cost of US$3 per gallon, would cost US$4.80.
Maintenance costs can be included in the comparison as well. Electric cars have expensive batteries that must be replaced but otherwise incur very low maintenance costs. The Tesla Roadster's very large battery pack is expected to last seven years with typical driving and costs US$12,000 when pre-purchased today.[30][31] Driving 40 miles (64 km) per day for seven years or 102,200 miles (164,500 km) leads to a battery consumption cost of US$0.1174 per 1 mile (1.6 km) or US$4.70 per 40 miles (64 km). The company Better Place provides another cost comparison as they anticipate meeting contractual obligations to deliver batteries as well as clean electricity to recharge the batteries at a total cost of US$0.08 per 1 mile (1.6 km) in 2010, US$0.04 per mile by 2015 and US$0.02 per mile by 2020.[32] 40 miles (64 km) of driving would initially cost US$3.20 and fall over time to US$0.80. The typical gasoline powered car can last 250,000 miles with some level of investment[citation needed] in maintenance. This cost comparison calculation for the electric car varies depending on the costs of gasoline and electricity, the mileages of the vehicles, the type of driving being considered, and the value to the owner of their fuel choice.
The Tesla Roadster uses about 17.4 kW·h/100 km (0.63 MJ/km; 0.280 kW·h/mi)[33], the EV1 used about 11 kW·h/100 km (0.40 MJ/km; 0.18 kW·h/mi).[34]
Nissan estimates the 5 year operating cost to US$1,800 and US$6,000 for a gasoline car.[35] The documentary film Who Killed the Electric Car?[36] shows a comparison between the parts that require replacement in a gasoline powered cars and EV1s, with the garages stating that they bring the electric cars in every 5,000 mi (8,000 km), rotate the tires, fill the windshield washer fluid and send them back out again. Even the hydraulic brakes require less maintenance because regenerative braking itself also slows the vehicle, as it does with a hybrid.
[edit] Range
The REVAi, also known as the G-Wiz, is the top-selling electric car in the world"Range anxiety" is a reason that many automakers marketed EVs as "daily drivers" suitable for city trips and other short hauls.[37] The average American drives less than 40 miles (64 km) per day; so the GM EV1 would have been adequate for the daily driving needs of about 90% of U.S. consumers.[36]
The Tesla Roadster gets 200 miles (320 km) per charge; more than double that of prototypes and evaluation fleet cars currently on the roads.[38] On Oct. 27, 2009, the Roadster set a new world record when customer Simon Hackett drove the entire 313 miles (504 km) of Australia's annual Global Green Challenge on a single charge.[39] The Roadster can be fully recharged in about 3.5 hours from a 220-volt, 70-amp home outlet.[40]
Several automakers and independent third-party companies are working on standard replaceable battery packs -- energy storage devices that could be "swapped" at conveniently located service stations in about as much the same time as a gasoline take refill.[41] The old battery would be recharged and the consumer would essentially lease a fully charged one.[42] The Tesla Model S sedan (a five-person car expected to be launched in 2012) is expected to have a swappable battery.[43]
In addition, it is expected to have a high-speed charging capability from 440-volt Three-phase industrial outlets so that consumers could refill in roughly 30 minutes.[43]
In April 21, 2010, Sanyo announced that it performed a 555.6 km travel from Tokyo to Osaka on a single charge with an electric Li-Ion batteries powered Daihatsu Mira[44]. May 25, 2010, Sanyo announced breaking its own record with a 1003 km travel at a training school for auto racers in Ibaraki[45]
[edit] Carbon dioxide emissions
Sources of electricity in the U.S. in 2009.[8]Electric cars produce no pollution at the tailpipe, but their use increases demand for electricity generation. Generating electricity and producing liquid fuels for vehicles are different categories of the energy economy, with different inefficiencies and environmental harms, but both emit carbon dioxide into the environment that must be accounted for in a "well to wheel" (WTW) comparison. An electric car's WTW emissions are much lower in a country like Canada, which electricity supply is dominated by hydro and nuclear, than in countries like China and the US that rely heavily on coal.
An EV recharged from the existing US grid electricity emits about 115 grams of CO2 per kilometer driven (6.5 oz(CO2)/mi), whereas a conventional US-market gasoline powered car emits 250 g(CO2)/km (14 oz(CO2)/mi) (most from its tailpipe, some from the production and distribution of gasoline).[46] The savings are questionable relative to hybrid or diesel cars, (according to official British government testing the most efficient European market cars are well below 115 grams of CO2 per kilometer driven, although a study in Scotland gave 81.4g CO2/km[47]), but would be more significant in countries with cleaner electric infrastructure. In a worst case scenario where incremental electricity demand would be met exclusively with coal, a 2009 study conducted by the WWF, World Wide Fund for Nature, and IZES found that a mid-size EV would emit roughly 200 g(CO2)/km (11 oz(CO2)/mi), compared with an average of 170 g(CO2)/km (9.7 oz(CO2)/mi) for a gasoline powered compact car.[48] This study concluded that introducing 1 million EV cars to Germany would, in the best case scenario, only reduce CO2 emissions by 0.1%, if nothing is done to upgrade the electricity infrastructure or manage demand.[48]
Like any other vehicles, EVs themselves of course differ in their fuel efficiency and their total cost of ownership, including the environmental costs of their manufacture and disposal.
48.5% of the electricity generated in the United States comes from coal-fired powerplantsAccording to the US Department of Energy, most electricity generation in the United States is from fossil sources, and almost half of that is from coal.[49] Coal is more carbon-intensive than oil. Overall average efficiency from US power plants (33% efficient) to point of use (transmission loss 9.5%) is 30%.[49] Accepting a 70% to 80% efficiency for the electric vehicle gives a figure of only around 20% overall efficiency when recharged from fossil fuels. That is comparable to the efficiency of an internal combustion engine running at variable load. The efficiency of a gasoline engine is about 16%, and 20% for a diesel engine.[50][51] This is much lower than the efficiency when running at constant load and optimal rotational speed, which gives efficiency around 30% and 45% respectively.[52] The electric battery suffers a smaller decrease in efficiency when running at variable load,[53] which accounts for the modest increased efficiency of hybrid vehicles. The actual result in terms of emissions depends on different refining and transportation costs getting fuel to a car versus a power plant. Diesel engines can also easily run on renewable fuels, biodiesel, vegetable oil fuel, with no loss of efficiency. Using fossil based grid electricity partially negates the high in-vehicle efficiency advantages of electric cars, though even with that drawback, the operation of a electric vehicle has a smaller carbon footprint than a gasoline car. This is because internal combustion engines, when used for propelling a vehicle, operate throughout their power band, which is hardly optimal for efficiency. A major potential benefit of electric cars is to allow diverse renewable electricity sources to fuel cars. A electric vehicle, recharged from renewable resources, would produce no carbon emissions at all, and provides the zenith of eco-friendly transportation.
According to the US Department of Energy, CO2 emissions for electricity generated from coal result in 2.05 lb (0.93 kg) of CO2 per kW·h or roughly 0.5 lb(CO2)/mi (0.14 kg(CO2)/km). CO2 emissions from electricity produced from all types of fuel using the mix of sources in the US as of 2008 results in 1.35 lb (0.61 kg) of CO2 per kW·h or 0.337 pounds of CO2 per mile (0.095 kg(CO2)/km) from an electric vehicle with a 0.250-kilowatt-hour-per-mile (0.155 kW·h/km; 0.56 MJ/km) energy consumption (typical). Gasoline used in Internal Combustion Engine automobiles produces 19.5 lbCO2/US gal (2.34 kg(CO2)/L) directly and an undetermined amount of CO2 in refining the crude oil, and transporting the gasoline to retail point of sale. With a US fleet average of 21.3 mpg-US (11.0 L/100 km; 25.6 mpg-imp) in 2008, this would indicate a CO2 production of 0.915 lb/mi (0.258 kg/km) driven. Electric powered automobiles, even using the most CO2 intensive coal produced electricity, produce half the emissions of gasoline powered automobiles.[54]
If solar, wind, hydro, or nuclear electric generation, or carbon capture for fossil fuel powered plants were to become prevalent, electric vehicles could produce less CO2, potentially zero. Based on GREET simulations, electric cars can achieve up to 100% reductions with renewable electric generation, against 77% with a B100 car. At present only a 32% reduction of CO2 is available for electric cars recharging from non-renewable utilities on the US Grid, because of the majority use of fossil fuels in generation, and inefficiency in the grid itself.[49][55][56]
[edit] 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.
Although some electric vehicles have very small motors, 15 kW (20 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. Another early solution was American Motors’ experimental Amitron piggyback system of batteries with one type designed for sustained speeds while a different set boosted acceleration when needed.
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. In some cases, the motor can be housed directly in the wheel, such as in the Whispering Wheel design, which lowers the vehicle's center of gravity and reduces the number of moving parts. When not fitted with an axle, differential, or transmission, electric vehicles have less drivetrain rotational inertia.
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, and applying mild regenerative braking instead provides a more familiar response.
A gearless or single gear design in some EVs eliminates the need for gear shifting, giving such vehicles both smoother acceleration and smoother braking. Because the torque of an electric motor is a function of current, not rotational speed, electric vehicles have a high torque over a larger range of speeds during acceleration, as compared to an internal combustion engine. As there is no delay in developing torque in an EV, EV drivers report generally high satisfaction with acceleration.
For example, the Venturi Fetish delivers supercar acceleration despite a relatively modest 220 kW (295 hp), and top speed of around 160 km/h (100 mph). Some DC motor-equipped drag racer EVs, have simple two-speed transmissions to improve top speed.[57] The Tesla Roadster prototype can reach 100 km/h (62 mph) in 4 seconds with a motor rated at 185 kW (248 hp).[58]
[edit] Energy efficiency
Indica Vista EV[59]
XD Concept[60]Main articles: Fuel efficiency, Electrical efficiency, Thermal efficiency, and Energy efficiency
Proponents of electric cars usually tout an increased efficiency as the primary advantage of an electric vehicle as compared to one powered by an internal combustion engine. The energy efficiency comparison is difficult to make because the two vehicles operate on different principles. Vehicles powered by internal combustion engines operate by converting energy stored in fossil fuels to mechanical energy through the use of a heat engine. Heat engines operate with very low efficiencies because heat cannot be converted directly into mechanical energy. Electric vehicles convert stored electric potential into mechanical energy. Electricity can be converted into mechanical energy at very high efficiencies. A quick analysis will show electric vehicles are significantly more efficient. However, electricity (in a form usable for humans) does not naturally exist in nature. The electricity used for electric cars may be created by converting fossil fuels to electricity using a heat engine (with a similar efficiency as an automotive engine), converting nuclear energy to electricity using a heat engine, or through dams, windmills, or solar energy. Each of these conversion processes operate with less than 100% efficiency and those involving heat engines operate at relatively low efficiencies.
When comparing the efficiencies of an electric vehicle to a gasoline vehicle, the efficiency of the source of generating the electric energy must be included in the comparison. For example, it may be incorrect to say that an electric vehicle charged each night from a gasoline powered generator is more efficient than a gasoline powered vehicle; one has to compare the gasoline to electricity to wheel efficiency of the electric vehicle with the gasoline to wheel efficiency of the conventional vehicle.
An electric car's efficiency is affected by its battery charging and discharging efficiencies, which ranges from 70% to 85%, and its engine and braking system. The electricity generating system in the US loses 9.5% of the power transmitted between the power station and the socket, and the power stations are 33% efficient in turning the calorific value of fuel at the power station to electrical power.[49] Overall this results in an efficiency of 20% to 25% from fuel into the power station, to power into the motor of the grid-charged EV, comparable or slightly better than the average 20% efficiency of gasoline-powered vehicles in urban driving, though worse than the about 45 % of modern Diesel engines running under optimal conditions (e.g. on motorways). Neither analysis includes the energy required to mine and transport the coal or produce, refine, and distribute the gasoline.
Production and conversion electric cars typically use 10 to 23 kW·h/100 km (0.17 to 0.37 kW·h/mi).[34][61] 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).[62] The US fleet average of 10 l/100 km (24 mpg-US) of gasoline is equivalent to 96 kW·h/100 km (1.58 kW·h/mi), and the Honda Insight uses 32 kW·h/100 km (0.52 kW·h/mi) (assuming 9.6 kW·h per liter of gasoline).
The greater efficiency of electric vehicles is primarily because most energy in a gasoline-powered vehicle is released as waste heat. With an engine getting only 20% thermal efficiency, a gasoline-powered vehicle using 96 kW·h/100 km of energy is only using 19.2 kW·h/100 km for motion.
Gasoline contains about 80 times as much energy, by weight, as the best lithium-ion battery. In 2010, the Washington Post commented that because of the difficulty of charging unreliable batteries, the electric car is the "next big thing - and it always will be."[20]
The waste heat generated by an ICE is frequently put to beneficial use by heating the vehicle interior. Electric vehicles generate very little waste heat and resistance electric heat may have to be used to heat the interior of the vehicle if heat generated from battery charging/discharging can not be used to heat the interior. Electric vehicles used in cold weather will show increased energy consumption and decreased range on a single charge.
[edit] Safety
The REVAi, also known as the G-Wiz i, is currently the world's top-selling battery electric car.[63][64] It has a range of 80 km (50 mi).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.
Firefighters and rescue personnel receive special training to deal with the higher voltages and chemicals encountered in electric and hybrid electric vehicle accidents. While BEV accidents may present unusual problems, such as fires and fumes resulting from rapid battery discharge, there is apparently no available information regarding whether they are inherently more or less dangerous than gasoline or diesel internal combustion vehicles which carry flammable fuels.
[edit] Vehicle safety
The CT&T United eZone, an electric car that has been crash testedGreat effort is taken to keep the mass of an electric vehicle as low as possible, in order to improve the EV's range and endurance. Despite these efforts, the high density and weight of the electric batteries usually results in an EV being heavier than a similar equivalent gasoline vehicle leading to less interior space, and 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[65] despite having a negative effect on the car's performance.[66] An accident in a 2,000 lb (900 kg) vehicle will on average cause about 50% more injuries to its occupants than a 3,000 lb (1,400 kg) vehicle.[67][68] In a single car accident,[citation needed] 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.[69][70][71] Many electric cars have a small, light and fragile body, though, and therefore offer inadequate safety protection. Because of this, the Insurance Institute for Highway Safety in America had condemned the use of such vehicles.[72]
[edit] Hazard to pedestrians
At low speeds, electric cars produced much less roadway noise as compared to vehicles propelled by a internal combustion engine. However, the reduced noise level from electric engines may not be beneficial for all road users, as 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.[73][74] Tests have shown that this is a valid concern, as vehicles operating in electric mode can be particularly hard to hear below 20 mph (30 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 more audible noise.[74] The US Congress and the European Commission are exploring legislation to establish a minimum level of sound for electric and hybrid 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.[74]
[edit] Cabin heating and cooling
While heating can be simply provided with an electric resistance heater, higher efficiency and integral cooling can be obtained with a reversible heat pump (this is currently implemented in the hybrid Toyota Prius). Positive Temperature Constant (PTC) junction cooling[75] is also attractive for its simplicity - this kind of system is used for example in the Tesla Roadster. However some electric cars, for example the Citroën Berlingo Electrique, use an auxiliary heating system (for example gasoline-fueled units manufactured by Webasto or Eberspächer). Cabin cooling can be augmented with solar power, most simply and effectively by inducting outside air to avoid extreme heat buildup when the vehicle is closed and parked in the sunlight (such cooling mechanisms are available as aftermarket kits for conventional vehicles). Two models of the 2010 Toyota Prius include this feature as an option.[76]
[edit] Regenerative braking
Main article: Regenerative braking
Using regenerative braking, a feature which is present on many electric and hybrid vehicles, estimates of 71-93% of the energy used to accelerate the mass of the vehicle may be recovered during braking,[77] increasing its efficiency, particularly in urban drive cycles.
[edit] Batteries
Prototypes of 75 watt-hour/kilogram lithium-ion polymer battery. Newer lithium-ion cells can provide up to 130 W·h/kg and last through thousands of charging cycles.Main article: Electric vehicle battery
Rechargeable battery materials used in electric vehicles include lead-acid ("flooded" and VRLA), NiCd, nickel metal hydride, lithium-ion, Li-ion polymer, and, less commonly, zinc-air and molten salt. The Lithium iron phosphate battery is currently one of the most promising electric vehicle battery variants due to its light weight, high energy density, and lack of thermal runaway issues that have plagued laptop computer lithium-ion batteries. The amount of electricity stored in batteries is measured in ampere hours or coulombs, with the total energy often measured in watt hours.
Historically, EVs and PHEVs have had problems with high battery costs, limited range between battery recharging, charging time, and battery lifespan, which have limited their widespread adoption. Ongoing battery technology advancements have reduced many of these problems; many models have recently been prototyped, and a few future production models have been announced.
[edit] Charging
Project Better Place charging stationsMain article: charging station
Batteries in BEVs must be periodically recharged (see also Replacing, below). BEVs most commonly charge from the power grid (at home or using a street or shop charging station), which is in turn generated from a variety of domestic resources; such as coal, hydroelectricity, nuclear and others. Home power such as roof top photovoltaic solar cell panels, micro hydro or wind may also be used and are promoted because of concerns regarding global warming.
[edit] Level 1, 2, and 3 charging
Charging station at Rio de Janeiro, Brazil. This station is run by Petrobras and uses solar energy.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.
Level Original definition[78] Recent definition[79] Connectors
Level 1 AC energy to the vehicles an on-board charger; from the most common U.S. grounded household receptacle, commonly referred to as a 110 volt outlet. 120 V AC; 16 A SAE J1772 (16.8 kW)
Level 2 AC energy to the vehicles an on-board charger;208-240 volt, single phase. The maximum current specified is 32 amps (continuous) with a branch circuit breaker rated at 40 amps. Maximum continuous input power is specified as 7.68 kW. 208-240 V AC;
12 A to 80 A SAE J1772 (16.8 kW)
IEC 62196 (44 kW)
Magne Charge
IEC 60309 16 A (3.8 kW)
Level 3 DC energy from an off-board charger; there is no minimum energy requirement but the maximum current specified is 400 amps and 240 kW continuous power supplied. very high voltages (300-500 V DC); very high currents (100s of Amperes) CHΛdeMO (62.5 kW)
[edit] 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[80] as the charging interface for electric vehicles in California in June 2001.[81]
Level 1 charging this can be as simple as a mains lead from the car into a weatherproof socket
Level 2 charging at low current may be possible with a mains lead at the higher voltage that is standard across Europe and the majority of the world and that is available from North American dryer sockets. However, depending on local electrical regulations, a dedicated charging station may be required with a special high-capacity cable running to the car with connectors and signaling logic to protect the user from the higher voltage. For example, in the U.S. electrical regulations require the charging station to be permanently wired to an AC outlet and the cable to have an interlock that de-energizes the electric vehicle connector and its cable whenever the electric connector is uncoupled from the electric vehicle.[82]
Level 3 charging always requires an external rectifier to convert voltage to high voltage DC with a special electrical connection, special cabling, and signalling logic.
Modern standards for connectors include SAE J1772-2009 (level 1 and 2 charging), IEC 62196 (level 1, 2 and three-phase charging), and CHAdeMO (level 3 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.
[edit] Charging time
Charging station and Nissan LeafMore 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 230V supply). The main connection to a house might be able to sustain 10 kW, and special wiring can be installed to use this. As examples of on-board chargers, the Nissan Leaf at launch will have a 3.3 kW charger[83] and the Tesla Roadster appears to accept 16.8 kW (240V at 70A) from the Tesla Home Connector.[84] These power numbers are small compared to the effective power delivery rate of an average petrol pump, about 5,000 kW. Even if the electrical supply power can be increased, most batteries do not accept charge at greater than their charge rate ("1C"), because high charge rates have an adverse effect on the discharge capacities of batteries.[85] Despite these power limitations, plugging in to even the least-powerful conventional home outlet provides more than 15 kilowatt-hours of energy overnight, sufficient to propel most electric cars more than 70 kilometres (43 mi) (see Energy efficiency below).
[edit] Faster charging
In 1995, some charging stations charged BEVs in one hour. In November 1997, Ford purchased a fast-charge system produced by AeroVironment called "PosiCharge" for testing its fleets of Ranger EVs, which charged their lead-acid batteries in between six and fifteen minutes. In February 1998, General Motors announced a version of its "Magne Charge" system which could recharge NiMH batteries in about ten minutes, providing a range of 60 to 100 mi (100 to 160 km).[86]
In 2005, mobile device battery designs by Toshiba were claimed to be able to accept an 80% charge in as little as 60 seconds.[87] Scaling this specific power characteristic up to the same 7 kW·h EV pack would result in the need for a peak of 340 kW from some source for those 60 seconds. It is not clear that such batteries will work directly in BEVs as heat build-up may make them unsafe.
Altairnano's NanoSafe batteries can be recharged in several minutes, versus hours required for other rechargeable batteries. A NanoSafe cell can be charged to around 95% charge capacity in approximately 10 minutes.[88][89]
Most people do not usually require fast recharging because they have enough time, 30 minutes to six hours (depending on discharge level) during the work day or overnight at home to recharge. The charging does not require attention so it takes only a few seconds of the owner's time for plugging and unplugging the charging source. BEV drivers frequently prefer recharging at home, avoiding the inconvenience of visiting a public charging station. Some workplaces provide special parking bays for electric vehicles with chargers provided - sometimes powered by solar panels. In colder areas such as Finland, some northern US states and Canada there already exists some infrastructure for public power outlets, in parking garages and at parking meters, provided primarily for use by block heaters and set with circuit breakers that prevent large current draws for other uses.[90]
[edit] Travel range before recharging
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. The range of an electric vehicle conversion depends on the battery type:
Lead acid batteries are still the most used form of power for most of the electric vehicles used today. Compared to e.g. lithium-ion batteries, they are up to 3x cheaper. The initial construction costs are significantly lower than for other battery types, and while power output to weight is poorer than other designs, range and power can be easily added by increasing the number of batteries.[91]
Manufacturers are not using these batteries in new designs because of the greater maintenance costs compared with solid batteries and the weight and bulk which affects the handling and space of the vehicle.
They are the principal form of battery in non-road going electric vehicles such as mobility scooters and electric forklifts.
Most non-commercial conversions generally have a range of 30 to 80 km (20 to 50 mi). Production EVs with lead-acid batteries are capable of up to 130 km (80 mi) per charge.
NiMH batteries have higher energy density and may deliver up to 200 km (120 mi) of range.
The lithium-ion battery in the AC Propulsion tzero provides 400 to 500 km (200 to 300 mi) of range per charge.[92] The list price of this vehicle when it was released in 2003 was US$220,000.[93]
Lithium is also less expensive than nickel.[94]
Finding the economic balance of range against performance, battery capacity versus weight, and battery type versus cost challenges every EV manufacturer.
[edit] Replacing
The Renault Fluence Z.E. plans to have replaceable batteries. Available in 2011 in Europe.An alternative to quick recharging is to exchange the drained or nearly drained batteries (or battery range extender modules) with fully charged batteries, rather as stagecoach horses were changed at coaching inns. Batteries could be leased or rented instead of bought, and then maintenance deferred to the leasing or rental company, and ensures availability. In 1947, in Nissan's first electric car, the batteries were removable so that they could be replaced at filling stations with fully charged ones. Renault announced at the 2009 Frankfurt Motor Show that they have sponsored a network of charging stations and plug-in plug-out battery swap stations.[95] Other vehicle manufacturers and companies are also investigating the possibility.
Replaceable batteries were used in the electric buses at the 2008 Summer Olympics.[96]
[edit] Refilling
Zinc-bromine flow batteries or Vanadium redox batteries can be refilled, instead of recharged, saving time. The depleted electrolyte can be recharged at the point of exchange, or taken away to a remote station.
[edit] Vehicle-to-grid: uploading and grid buffering
Main article: Vehicle-to-grid
See also: Economy 7 and load balancing (electrical power)
A Smart grid allows BEVs to provide power to the grid, specifically:
During peak load periods, when the cost of electricity can be very high. 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.
During blackouts, as an emergency backup supply.
The basic premise here is similar to Economy 7 in the United Kingdom: incentives to spread the load more evenly across the day reduces the need for expensive peak demand and thus the need to building power stations that can supply it on demand.
[edit] Lifespan
Individual batteries are usually arranged into large battery packs of various voltage and ampere-hour capacity products to give the required energy capacity. 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 a number of factors.
The depth of discharge (DOD) is the recommended proportion of the total available energy storage for which that battery will achieve its rated cycles. Deep cycle lead-acid batteries generally should not be discharged below 80% capacity. More modern formulations can survive deeper cycles.
In real world use, some fleet Toyota RAV4 EVs, using NiMH batteries will exceed 160 000 km (100,000 mi), and have had little degradation in their daily range.[97] Quoting that report's concluding assessment:
The five-vehicle test is demonstrating the long-term durability of Nickel Metal Hydride batteries and electric drive trains. Only slight performance degradation has been observed to-date on four out of five vehicles.... EVTC test data provide strong evidence that all five vehicles will exceed the 100,000-mile (160,000 km) mark. SCE’s positive experience points to the very strong likelihood of a 130,000-to-150,000-mile (210,000 to 240,000 km) Nickel Metal Hydride battery and drive-train operational life. EVs can therefore match or exceed the lifecycle miles of comparable internal combustion engine vehicles.
In June 2003 the 320 RAV4 EVs of the SCE fleet were used primarily by meter readers, service managers, field representatives, service planners and mail handlers, and for security patrols and carpools. In five years of operation, the RAV4 EV fleet had logged more than 6.9 million miles, eliminating about 830 tons of air pollutants, and preventing more than 3,700 tons of tailpipe CO2 emissions. Given the successful operation of its EVs to-date, SCE plans to continue using them well after they all log 100,000 miles (160,000 km).
Jay Leno's 1909 Baker Electric still operates on its original Edison cells. Battery replacement costs of BEVs may be partially or fully offset by the elimination of some regular maintenance, such as oil and filter changes required for ICEVs, and by the greater reliability of BEVs due to their fewer moving parts. They also do away with many other parts that normally require servicing and maintenance in a regular car, such as on the gearbox, cooling system, and engine tuning. And by the time batteries do finally need definitive replacement, they can be replaced with later generation ones which may offer better performance characteristics, in the same way one might replace an old laptop or mobile phone battery.
[edit] Future
[edit] Battery technology
Main article: Electric vehicle battery
The Tesla Roadster was the first production automobile to use lithium-ion battery cells and the first production all-electric vehicle with a range of 244 miles (393 km) per charge.[98][99]The future of battery electric vehicles depends primarily upon the cost and availability of batteries with high energy densities, power density, short charge time and long life, as all other aspects such as motors, motor controllers, and chargers are fairly mature and cost-competitive with internal combustion engine components. Li-ion, Li-poly and zinc-air batteries have demonstrated energy densities high enough to deliver range and recharge times comparable to conventional vehicles.[citation needed]By the year 2020, an estimated 30% of the cars driving on the road will be battery, electric or plug-in hybrid.[100]
It is estimated that there are sufficient li-ion reserves to power 4 billion electric cars.[101]
The cathodes of early 2007 lithium-ion batteries are made from lithium-cobalt metal oxide. That material is expensive, and can release oxygen if its cell is overcharged. If the cobalt is replaced with iron phosphates, the cells will not burn or release oxygen under any charge. The price premium for early 2007 hybrids is about US$5,000, some US$3,000 of which is for their NiMH battery packs. At early 2007 gasoline and electricity prices, that would break even after six to ten years of operation. The hybrid premium could fall to US$2,000 in five years, with US$1,200 or more of that being cost of lithium-ion batteries, breaking even after three years.[102]
[edit] 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.[103] 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).
EEStor claims to have developed a supercapacitor for electricity storage. These units are titanate coated with aluminum oxide and glass to achieve a level of capacitance claimed to be much higher than that currently available on the market. The claimed energy density is 1.0 MJ/kg whereas existing commercial supercapacitors typically have an energy density of around 0.01 MJ/kg, while lithium-ion batteries have an energy density of around 0.59 MJ/kg to 0.95 MJ/kg). EEStor claims that a 5 minute charge should give the supercapacitor enough energy to give a car a range of 400 km (250 mi).[104]
[edit] Solar cars
Main articles: Solar taxi and Solar vehicle
Solar cars are electric cars that derive most or all of their electricity from built in solar panels. After the 2005 World Solar Challenge established that solar race cars could exceed highway speeds, the specifications were changed to provide for vehicles that with little modification could be used for transportation.
[edit] Electric car use by country
Main article: Electric car use by country
[edit] Hobbyists, conversions, and racing
Eliica prototypeHobbyists often build their own EVs by converting existing production cars to run solely on electricity. There is a cottage industry supporting the conversion and construction of BEVs by hobbyists. Universities such as the University of California, Irvine even build their own custom electric or hybrid-electric cars from scratch.
Short-range battery electric vehicles can offer the hobbyist comfort, utility, and quickness, sacrificing only range. Short-range EVs may be built using high-performance lead–acid batteries, using about half the mass needed for a 100 to 130 km (60 to 80 mi) range. The result is a vehicle with about a 50 km (30 mi) range, which, when designed with appropriate weight distribution (40/60 front to rear), does not require power steering, offers exceptional acceleration in the lower end of its operating range, and is freeway capable and legal. But their EVs are expensive due to the higher cost for these higher-performance batteries. By including a manual transmission, short-range EVs can obtain both better performance and greater efficiency than the single-speed EVs developed by major manufacturers. Unlike the converted golf carts used for neighborhood electric vehicles, short-range EVs may be operated on typical suburban throughways (where 60 to 70 km/h (37 to 43 mph) speed limits are typical) and can keep up with traffic typical on such roads and the short "slow-lane" on-and-off segments of freeways common in suburban areas.
Faced with chronic fuel shortage on the Gaza Strip, Palestinian electrical engineer Waseem Othman al-Khozendar invented in 2008 a way to convert his car to run on 32 electric batteries. According to al-Khozendar, the batteries can be charged with US$2 worth of electricity to drive from 180 to 240 km (110 to 150 mi). After a 7-hour charge, the car should also be able to run up to a speed of 100 km/h (60 mph). As electricity is supplied to Gaza by Israel, this may be seen not only as a way to combat climate changes and fuel shortage, but also as a way of making peace.[105][106]
Japanese Professor Hiroshi Shimizu from Faculty of Environmental Information of the Keio University created an electric limousine: the Eliica (Electric Lithium-Ion Car) has eight wheels with electric 55 kW hub motors (8WD) with an output of 470 kW and zero emissions, a top speed of 370 km/h (230 mph), and a maximum range of 320 km (200 mi) provided by lithium-ion batteries.[107] However, current models cost approximately US$300,000, about one third of which is the cost of the batteries.
In 2008, several Chinese manufacturers began marketing lithium iron phosphate (LiFePO4) batteries directly to hobbyists and vehicle conversion shops. These batteries offered much better power to weight ratios allowing vehicle conversions to typically achieve 75 to 150 mi (120 to 240 km) per charge. Prices gradually declined to approximately US$350 per kW·h by mid 2009. As the LiFePO4 cells feature life ratings of 3,000 cycles, compared to typical lead acid battery ratings of 300 cycles, the life expectancy of LiFePO4 cells is around 10 years. This has led to a resurgence in the number of vehicles converted by individuals. LiFePO4 cells do require more expensive battery management and charging systems than lead acid batteries.[citation needed]
[edit] Alternative green vehicles
Main article: Green vehicle#Types
Other types of green vehicles include vehicles that move fully or partly on alternative energy sources rather than fossil fuel. Another option is to use alternative fuel composition in conventional fossil fuel-based vehicles, making them go partly on renewable energy sources.
Other approaches include personal rapid transit, a public transportation concept that offers automated on-demand non-stop transportation, on a network of specially-built guideways.
[edit] Currently available electric cars
Main article: Currently available electric cars
The Nissan Leaf, scheduled for sales beginning in December 2010, is eligible for tax incentives and grants in Japan, the U.S., and several European countries.There are several types of electric cars available in regional markets such as neighborhood electric vehicles, electric city cars and highway-capable electric cars such as the Tesla Roadster in the U.S. and Europe, and the Mitsubishi i MiEV in Japan and Hong Kong. There are also many electric car projects that are not yet available but are at an advanced stage of development or field testing, such as the Nissan Leaf and the Mini E.
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,.[108] and several states have additional incentives.[109] The U.K. offers a purchase grant up to a maximum of GB£5,000 (US$7,600) beginning in January 2011.[110][111] As of April 2010, 15 European Union member states provide tax incentives for electrically chargeable vehicles, which consist of tax reductions and exemptions, as well as of bonus payments for buyers of PEVs and hybrid vehicles.[112][113]
[edit] Prototype electric cars
See also: List of production battery electric vehicles#Cars planned for production
The following electric cars are currently in an advanced stage of development.
[edit] Highway capable
Cars capable of at least 100 km/h (62 mph)
Model Top speed Acceleration Capacity
Adults+kids Charging time Nominal range Market release date
Tesla Model S 193 km/h (120 mph) 0 to 97 km/h (0 to 60 mph) in 5.6 s 5+2 Full charge 3.5 hours using the High Power Connector or 45 minute QuickCharge 483 km (300 mi) 2011
REVA NXR 104 km/h (65 mph) 4 160 km (99 mi) 2010
REVA NXG 130 km/h (81 mph) 2 200 km (120 mi) 2011
Nissan Leaf 145 km/h (90 mph) 5 8 hours with standard AC power; 30 minute rapid charge to 80% 161 km (100 mi) Late 2010
Optimal Energy Joule 130 km/h 0–50 km/h in 4.6 sec, 0–100 km/h in 14 seconds 5 7 hours (maximum) 300 km 2010
XD Concept 130 km/h (81 mph) 0–100 km/h in 7.7 seconds 3 0-80% approx. 6 hours, 230 V/16A
0-100% approx. 8 hours, 230 V/16A
250 km (160 mi) 2010
CODA Sedan 129 km/h (80 mph) 0–60 mi/h in 11 seconds 4 full charge in approx. 6 hours 193 km (120 mi) Fall 2010
Recycling involves processing used materials into new products to prevent waste of potentially useful materials, reduce the consumption of fresh raw materials, reduce energy usage, reduce air pollution (from incineration) and water pollution (from landfilling) by reducing the need for "conventional" waste disposal, and lower greenhouse gas emissions as compared to virgin production.[1][2] Recycling is a key component of modern waste reduction and is the third component of the "Reduce, Reuse, Recycle" waste hierarchy.
Recyclable materials include many kinds of glass, paper, metal, plastic, textiles, and electronics. Although similar in effect, the composting or other reuse of biodegradable waste – such as food or garden waste – is not typically considered recycling.[2] Materials to be recycled are either brought to a collection center or picked up from the curbside, then sorted, cleaned, and reprocessed into new materials bound for manufacturing.
In a strict sense, recycling of a material would produce a fresh supply of the same material, for example used office paper to more office paper, or used foamed polystyrene to more polystyrene. However, this is often difficult or too expensive (compared with producing the same product from raw materials or other sources), so "recycling" of many products or materials involves their reuse in producing different materials (e.g., paperboard) instead. Another form of recycling is the salvage of certain materials from complex products, either due to their intrinsic value (e.g., lead from car batteries, or gold from computer components), or due to their hazardous nature (e.g., removal and reuse of mercury from various items).
Critics dispute the net economic and environmental benefits of recycling over its costs, and suggest that proponents of recycling often make matters worse and suffer from confirmation bias. Specifically, critics argue that the costs and energy used in collection and transportation detract from (and outweigh) the costs and energy saved in the production process; also that the jobs produced by the recycling industry can be a poor trade for the jobs lost in logging, mining, and other industries associated with virgin production; and that materials such as paper pulp can only be recycled a few times before material degradation prevents further recycling. Proponents of recycling dispute each of these claims, and the validity of arguments from both sides has led to enduring controversy.
History
Early recycling
Recycling has been a common practice for most of human history, with recorded advocates as far back as Plato in 400 BC. During periods when resources were scarce, archaeological studies of ancient waste dumps show less household waste (such as ash, broken tools and pottery)—implying more waste was being recycled in the absence of new material.[3]
In pre-industrial times, there is evidence of scrap bronze and other metals being collected in Europe and melted down for perpetual reuse.[4] In Britain dust and ash from wood and coal fires was collected by 'dustmen' and downcycled as a base material used in brick making. The main driver for these types of recycling was the economic advantage of obtaining recycled feedstock instead of acquiring virgin material, as well as a lack of public waste removal in ever more densely populated areas.[3] In 1813, Benjamin Law developed the process of turning rags into 'shoddy' and 'mungo' wool in Batley, Yorkshire. This material combined recycled fibres with virgin wool. The West Yorkshire shoddy industry in towns such as Batley and Dewsbury, lasted from the early 1800s to at least 1914
Publicity photo for US aluminium salvage campaign, 1942Wartime recycling
Resource shortages caused by the world wars, and other such world-changing occurrences greatly encouraged recycling.[5] Massive government promotion campaigns were carried out in World War II in every country involved in the war, urging citizens to donate metals and conserve fibre, as a matter of significant patriotic importance. Resource conservation programs established during the war were continued in some countries without an abundance of natural resources, such as Japan, after the war ended.
Post-war recycling
The next big investment in recycling occurred in the 1970s, due to rising energy costs. Recycling aluminium uses only 5% of the energy required by virgin production; glass, paper and metals have less dramatic but very significant energy savings when recycled feedstock is used.[6]
Woodbury, New Jersey was the first city in the entire United States to mandate recycling.[7] Led by Rose Rowan[8] in the early 1970s, the idea of towing a "recycling" trailer behind a waste management vehicle to enable the collection of trash and recyclable material at the same time emerged. Other towns and cities soon followed suit, and today many cities in the U.S. make recycling a requirement.
In 1987, the Mobro 4000 barge hauled garbage from New York to North Carolina; where it was denied. It was then sent to Belize; where it was denied as well. Finally, the barge returned to New York and the garbage was incinerated. The incident led to heated discussions in the media about waste disposal and recycling. The incident is often referred to as igniting the recycling "hysteria" of the 1990s.[4]
Legislation
Supply
A recycling bin in Half Moon Bay, California.For a recycling program to work, having a large, stable supply of recyclable material is crucial. Three legislative options have been used to create such a supply: mandatory recycling collection, container deposit legislation, and refuse bans. Mandatory collection laws set recycling targets for cities to aim for, usually in the form that a certain percentage of a material must be diverted from the city's waste stream by a target date. The city is then responsible for working to meet this target.[2]
Container deposit legislation involves offering a refund for the return of certain containers, typically glass, plastic, and metal. When a product in such a container is purchased, a small surcharge is added to the price. This surcharge can be reclaimed by the consumer if the container is returned to a collection point. These programs have been very successful, often resulting in an 80% recycling rate. Despite such good results, the shift in collection costs from local government to industry and consumers has created strong opposition to the creation of such programs in some areas.[2]
A third method of increase supply of recyclates is to ban the disposal of certain materials as waste, often including used oil, old batteries, tires and garden waste. One aim of this method is to create a viable economy for proper disposal of banned products. Care must be taken that enough of these recycling services exist, or such bans simply lead to increased illegal dumping.[2]
Government-mandated demand
Legislation has also been used to increase and maintain a demand for recycled materials. Four methods of such legislation exist: minimum recycled content mandates, utilization rates, procurement policies, recycled product labeling.[2]
Both minimum recycled content mandates and utilization rates increase demand directly by forcing manufacturers to include recycling in their operations. Content mandates specify that a certain percentage of a new product must consist of recycled material. Utilization rates are a more flexible option: industries are permitted to meet the recycling targets at any point of their operation or even contract recycling out in exchange for tradeable credits. Opponents to both of these methods point to the large increase in reporting requirements they impose, and claim that they rob industry of necessary flexibility.[2][9]
Governments have used their own purchasing power to increase recycling demand through what are called "procurement policies". These policies are either "set-asides", which earmark a certain amount of spending solely towards recycled products, or "price preference" programs which provide a larger budget when recycled items are purchased. Additional regulations can target specific cases: in the United States, for example, the Environmental Protection Agency mandates the purchase of oil, paper, tires and building insulation from recycled or re-refined sources whenever possible.[2]
The final government regulation towards increased demand is recycled product labeling. When producers are required to label their packaging with amount of recycled material in the product (including the packaging), consumers are better able to make educated choices. Consumers with sufficient buying power can then choose more environmentally conscious options, prompt producers to increase the amount of recycled material in their products, and indirectly increase demand. Standardized recycling labeling can also have a positive effect on supply of recyclates if the labeling includes information on how and where the product can be recycled.[2]
Process
Collection
Recycling and rubbish bin in a German railway station.A number of different systems have been implemented to collect recyclates from the general waste stream. These systems tend to lie along the spectrum of trade-off between public convenience and government ease and expense. The three main categories of collection are "drop-off centres", "buy-back centres" and "curbside collection".[2]
Drop-off centres require the waste producer to carry the recyclates to a central location, either an installed or mobile collection station or the reprocessing plant itself. They are the easiest type of collection to establish, but suffer from low and unpredictable throughput. Buy-back centres differ in that the cleaned recyclates are purchased, thus providing a clear incentive for use and creating a stable supply. The post-processed material can then be sold on, hopefully creating a profit. Unfortunately government subsidies are necessary to make buy-back centres a viable enterprise, as according to the United States Nation Solid Wastes Management Association it costs on average US$50 to process a ton of material, which can only be resold for US$30.[2]
Curbside collection
Main article: Curbside collection
Curbside collection encompasses many subtly different systems, which differ mostly on where in the process the recyclates are sorted and cleaned. The main categories are mixed waste collection, commingled recyclables and source separation.[2] A waste collection vehicle generally picks up the waste.
A recycling truck collecting the contents of a recycling bin in Canberra, AustraliaAt one end of the spectrum is mixed waste collection, in which all recyclates are collected mixed in with the rest of the waste, and the desired material is then sorted out and cleaned at a central sorting facility. This results in a large amount of recyclable waste, paper especially, being too soiled to reprocess, but has advantages as well: the city need not pay for a separate collection of recyclates and no public education is needed. Any changes to which materials are recyclable is easy to accommodate as all sorting happens in a central location.[2]
In a Commingled or single-stream system, all recyclables for collection are mixed but kept separate from other waste. This greatly reduces the need for post-collection cleaning but does require public education on what materials are recyclable.[2][4]
Source separation is the other extreme, where each material is cleaned and sorted prior to collection. This method requires the least post-collection sorting and produces the purest recyclates, but incurs additional operating costs for collection of each separate material. An extensive public education program is also required, which must be successful if recyclate contamination is to be avoided.[2]
Source separation used to be the preferred method due to the high sorting costs incurred by commingled collection. Advances in sorting technology (see sorting below), however, have lowered this overhead substantially—many areas which had developed source separation programs have since switched to comingled collection.[4]
Sorting
Early sorting of recyclable materials: glass and plastic bottles (Poland)Once commingled recyclates are collected and delivered to a central collection facility, the different types of materials must be sorted. This is done in a series of stages, many of which involve automated processes such that a truck-load of material can be fully sorted in less than an hour.[4] Some plants can now sort the materials automatically, known as single-stream recycling. A 30 percent increase in recycling rates has been seen in the areas where these plants exist.[10]
Initially, the commingled recyclates are removed from the collection vehicle and placed on a conveyor belt spread out in a single layer. Large pieces of corrugated fiberboard and plastic bags are removed by hand at this stage, as they can cause later machinery to jam.[4]
Next, automated machinery separates the recyclates by weight, splitting lighter paper and plastic from heavier glass and metal. Cardboard is removed from the mixed paper, and the most common types of plastic, PET (#1) and HDPE (#2), are collected. This separation is usually done by hand, but has become automated in some sorting centers: a spectroscopic scanner is used to differentiate between different types of paper and plastic based on the absorbed wavelengths, and subsequently divert each material into the proper collection channel.[4]
Strong magnets are used to separate out ferrous metals, such as iron, steel, and tin-plated steel cans ("tin cans"). Non-ferrous metals are ejected by magnetic eddy currents in which a rotating magnetic field induces an electric current around the aluminium cans, which in turn creates a magnetic eddy current inside the cans. This magnetic eddy current is repulsed by a large magnetic field, and the cans are ejected from the rest of the recyclate stream.[4]
Finally, glass must be sorted by hand based on its color: brown, amber, green or clear.[4]
Cost-benefit analysis
+ Environmental effects of recycling[11]
Material Energy Savings Air Pollution Savings
Aluminium 95%[2][6] 95%[2][12]
Cardboard 24% —
Glass 5-30% 20%
Paper 40%[6] 73%
Plastics 70%[6] —
Steel 60%[4] —
There is some debate over whether recycling is economically efficient. Municipalities often see fiscal benefits from implementing recycling programs, largely due to the reduced landfill costs.[13] A study conducted by the Technical University of Denmark found that in 83% of cases, recycling is the most efficient method to dispose of household waste.[4][6] However, a 2004 assessment by the Danish Environmental Assessment Institute concluded that incineration was the most effective method for disposing of drink containers, even aluminium ones.[14]
Fiscal efficiency is separate from economic efficiency. Economic analysis of recycling includes what economists call externalities, which are unpriced costs and benefits that accrue to individuals outside of private transactions. Examples include: decreased air pollution and greenhouse gases from incineration, reduced hazardous waste leaching from landfills, reduced energy consumption, and reduced waste and resource consumption, which leads to a reduction in environmentally damaging mining and timber activity. About 4,000 minerals have been identified, of these around 100 can be called common, another several hundred are relatively common, and the rest are rare.[15] Without more recycling, zinc could be used up by 2037, both indium and hafnium could run out by 2017, and terbium could be gone before 2012.[16] At current rates, reserves of phosphorus will be depleted in the next 50 to 100 years.[17][18] Without mechanisms such as taxes or subsidies to internalize externalities, businesses will ignore them despite the costs imposed on society. To make such non-fiscal benefits economically relevant, advocates have pushed for legislative action to increase the demand for recycled materials.[2] The United States Environmental Protection Agency (EPA) has concluded in favor of recycling, saying that recycling efforts reduced the country's carbon emissions by a net 49 million metric tonnes in 2005.[4] In the United Kingdom, the Waste and Resources Action Programme stated that Great Britain's recycling efforts reduce CO2 emissions by 10-15 million tonnes a year.[4] Recycling is more efficient in densely populated areas, as there are economies of scale involved.[2]
Certain requirements must be met for recycling to be economically feasible and environmentally effective. These include an adequate source of recyclates, a system to extract those recyclates from the waste stream, a nearby factory capable of reprocessing the recyclates, and a potential demand for the recycled products. These last two requirements are often overlooked—without both an industrial market for production using the collected materials and a consumer market for the manufactured goods, recycling is incomplete and in fact only "collection".[2]
Many economists favor a moderate level of government intervention to provide recycling services. Economists of this mindset probably view product disposal as an externality of production and subsequently argue government is most capable of alleviating such a dilemma. However, those of the laissez faire approach to municipal recycling see product disposal as a service that consumers value. A free-market approach is more likely to suit the preferences of consumers since profit-seeking businesses have greater incentive to produce a quality product or service than does government. Moreover, economists most always advise against government intrusion in any market with little or no externalities.” [19]
Trade in recyclates
Computers being collected for recycling at a pickup event in Olympia, Washington, United States.Certain countries trade in unprocessed recyclates. Some have complained that the ultimate fate of recyclates sold to another country is unknown and they may end up in landfills instead of reprocessed. According to one report, in America, 50-80% of computers destined for recycling are actually not recycled.[20][21] There are reports of illegal-waste imports to China being dismantled and recycled solely for monetary gain, without consideration for workers' health or environmental damage. Though the Chinese government has banned these practices, it has not been able to eradicate them.[22] In 2008, the prices of recyclable waste plummeted before rebounding in 2009. Cardboard averaged about £53/tonne from 2004–2008, dropped to £19/tonne, and then went up to £59/tonne in May 2009. PET plastic averaged about £156/tonne, dropped to £75/tonne and then moved up to £195/tonne in May 2009.[23] Certain regions have difficulty using or exporting as much of a material as they recycle. This problem is most prevalent with glass: both Britain and the U.S. import large quantities of wine bottled in green glass. Though much of this glass is sent to be recycled, outside the American Midwest there is not enough wine production to use all of the reprocessed material. The extra must be downcycled into building materials or re-inserted into the regular waste stream.[2][4]
Similarly, the northwestern United States has difficulty finding markets for recycled newspaper, given the large number of pulp mills in the region as well as the proximity to Asian markets. In other areas of the U.S., however, demand for used newsprint has seen wide fluctuation.[2]
In some U.S. states, a program called RecycleBank pays people with coupons to recycle, receiving money from local municipalities for the reduction in landfill space which must be purchased. It uses a single stream process in which all material is automatically sorted.[24]
Look Good
Time to do something?