Environmental aspects of the electric car


s have several environmental benefits compared to conventional internal combustion engine cars. They have lower operating and maintenance costs, produce little or no local air pollution, reduce dependence on petroleum and also have the potential to reduce greenhouse gas emissions. Electric motors are significantly more efficient than internal combustion engines and thus, even accounting for distribution losses, less energy is required to operate an EV. Producing batteries for electric cars requires additional resources and energy, so they may have a larger environmental footprint when new. The UK government estimates two thirds of car particulate pollution arises from tire, brake and road dust. Since electric cars are heavier on average, they could produce more of this type of pollution than traditional vehicles. However, EVs' use of regenerative braking means that fewer particles are emitted by traditional braking. Lastly, electric cars are mechanically much simpler and are predicted to have a longer useful life, which can be beneficial for the environment since fewer cars are needed overall.

Advantages and disadvantages

Battery electric cars can have several environmental benefits over conventional internal combustion engine vehicles, such as:
Plug-in hybrids capture most of these benefits when they are operating in all-electric mode.
Electric cars have some disadvantages, such as:
As in combustion cars, the carbon dioxide emitted in manufacturing should be taken into account.

Lower operating and maintenance costs

have lower maintenance costs as compared to internal combustion vehicles, since electronic systems break down much less often than the mechanical systems in conventional vehicles, and the fewer mechanical systems on board last longer due to the better use of the electric engine. Electric cars do not require oil changes and other routine maintenance checks.
Internal combustion engines are relatively inefficient at converting on-board fuel energy to propulsion as most of the energy is wasted as heat, and the rest while the engine is idling. Electric motors, on the other hand, are more efficient at converting stored energy into driving a vehicle. Electric drive vehicles do not consume energy while at rest or coasting, and modern plug-in cars can capture and reuse as much as one fifth of the energy normally lost during braking through regenerative braking. Typically, conventional 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 efficiencies of 20%, while electric drive vehicles typically have on-board efficiencies of around 80%.

Electricity generation for electric cars

Electric cars usually also show significantly reduced greenhouse gas emissions, depending on the method used for electricity generation to charge the batteries. For example, battery electric and hydrogen vehicles do not produce emissions at all, but only if their energy comes from renewable electricity or low carbon sources like nuclear. Timing the charging process of electric vehicles according to the power generated by renewable power sources can increase the percentage of renewable energy in the electric grid.
Even when the power is generated using fossil fuels, electric vehicles usually, compared to gasoline vehicles, show significant reductions in overall well-to-wheels global carbon emissions due to the highly carbon-intensive production in mining, pumping, refining, transportation and the efficiencies obtained with gasoline. This means that even if part of the energy used to run an electric car comes from fossil fuels, electric cars will still contribute to reduce emissions, which is important since most countries' electricity is generated, at least in part, by burning fossil fuels. Researchers in Germany have claimed that, while there is some technical superiority of electric propulsion compared with conventional technology, in many countries the effect of electrification of vehicles' fleet emissions will predominantly be due to regulation rather than technology. Indeed, electricity production is submitted to emission quotas, while vehicles' fuel propulsion is not, thus electrification shifts demand from a non-capped sector to a capped sector. This means that the emissions of electrical grids can be expected to improve over time as more wind and solar generation is deployed and the efficiency of photovoltaic solar panels improves over time
Many, but not most or all countries are introducing average emissions targets across all cars sold by a manufacturer, with financial penalties on manufacturers that fail to meet these targets. This has created an incentive for manufacturers, especially those selling many heavy or high-performance cars, to introduce electric cars and turbocharged cars as a means of reducing average fleet emissions.

Air pollution and carbon emissions in various countries

Electric cars have several benefits over conventional internal combust engine automobiles, reduction of local air pollution, especially in cities, as they do not emit harmful tailpipe pollutants such as particulates, 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.
Charging a vehicle using renewable energy yields very low carbon footprint-only that to produce and install the generation system Even on a fossil-fueled grid, it's quite feasible for a household with a solar panel to produce enough energy to account for their electric car usage, thus cancelling out the emissions of charging the vehicle, whether or not the panel directly charges it. Even when using exclusively grid electricity, introducing EVs comes with a major environmental benefits in most countries, except those relying on old coal fired power plants. So for example the part of electricity, which is produced with renewable energy is in Norway 99 percent and in Germany 30 percent.

United Kingdom

Two thirds of automobile contamination arise from tire, brake, and road dust, the UK government disclosed in July 2019. Particulate matter pollution continues to increase even with electric cars.
A study made in the UK in 2008, concluded that electric vehicles had the potential to reduce carbon dioxide and greenhouse gas emissions by at least 40%, even taking into account the emissions due to current electricity generation in the UK and emissions relating to the production and disposal of electric vehicles. The savings are questionable relative to hybrid or diesel cars. But because UK consumers can select their energy suppliers, it also depends on how 'green' their chosen supplier is in providing energy into the grid. Unlike other countries, in the UK a stable proportion of the electricity is produced by nuclear, coal and gas plants. Therefore, there are only minor differences in the environmental impact over the year.

United States

The following table compares tailpipe and upstream emissions estimated by the U.S. Environmental Protection Agency for all series production model year 2014 all-electric passenger vehicles available in the U.S. market. Since all-electric cars do not produce tailpipe emissions, for comparison purposes the two most fuel efficient plug-in hybrids and the typical gasoline-powered car are included in the table. Total emissions include the emissions associated with the production and distribution of electricity used to charge the vehicle, and for plug-in hybrid electric vehicles, it also includes emissions associated with tailpipe emissions produced from the internal combustion engine. These figures were published by the EPA in October in its 2014 report "Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends."
To account for the upstream emissions associated with the production and distribution of electricity, and since electricity production in the United States varies significantly from region to region, the EPA considered three scenarios/ranges with the low end scenario corresponding to the California powerplant emissions factor, the middle of the range represented by the national average powerplant emissions factor, and the upper end of the range corresponding to the powerplant emissions factor for the Rocky Mountains. The EPA estimates that the electricity GHG emission factors for various regions of the country vary from 346 g /kWh in California to 986 g /kWh in the Rockies, with a national average of 648 g /kWh. In the case of plug-in hybrids, and since their all-electric range depends on the size of the battery pack, the analysis introduced a utility factor as a projection of the share of miles that will be driven using electricity by an average driver.
The Union of Concerned Scientists published in 2012, a report with an assessment of average greenhouse gas emissions resulting from charging plug-in car batteries considering the full life-cycle and the fuel used to generate electric power by region in the U.S. The study used the Nissan Leaf all-electric car to establish the analysis's baseline. The UCS study expressed the results in terms of miles per gallon instead of the conventional unit of grams of carbon dioxide emissions per year. The study found that in areas where electricity is generated from natural gas, nuclear, or renewable resources such as hydroelectric, the potential of plug-in electric cars to reduce greenhouse emissions is significant. On the other hand, in regions where a high proportion of power is generated from coal, hybrid electric cars produce less emissions than plug-in electric cars, and the best fuel efficient gasoline-powered subcompact car produces slightly less emissions than a plug-in car. In the worst-case scenario, the study estimated that for a region where all energy is generated from coal, a plug-in electric car would emit greenhouse gas emissions equivalent to a gasoline car rated at a combined city/highway fuel economy of. In contrast, in a region that is completely reliant on natural gas, the plug-in would be equivalent to a gasoline-powered car rated at combined.
The study found that for 45% of the U.S. population, a plug-in electric car will generate lower emissions than a gasoline-powered car capable of a combined fuel economy of, such as the Toyota Prius. Cities in this group included Portland, Oregon, San Francisco, Los Angeles, New York City, and Salt Lake City, and the cleanest cities achieved well-to-wheel emissions equivalent to a fuel economy of. The study also found that for 37% of the population, the electric car emissions will fall in the range of a gasoline-powered car rated at a combined fuel economy between, such as the Honda Civic Hybrid and the Lexus CT200h. Cities in this group include Phoenix, Arizona, Houston, Miami, Columbus, Ohio and Atlanta, Georgia. An 18% of the population lives in areas where the power supply is more dependent on burning carbon, and emissions will be equivalent to a car rated at a combined fuel economy between, such as the Chevrolet Cruze and Ford Focus. This group includes Denver, Minneapolis, Saint Louis, Missouri, Detroit, and Oklahoma City. The study found that there are no regions in the U.S. where plug-in electric cars will have higher greenhouse gas emissions than the average new compact gasoline engine automobile, and the area with the dirtiest power supply produces emissions equivalent to a gasoline-powered car rated.
In September 2014, the UCS published an updated analysis of its 2012 report. The 2014 analysis found that 60% of Americans, up from 45% in 2009, live in regions where an all-electric car produce fewer equivalent emissions per mile than the most efficient hybrid. The UCS study found two reasons for the improvement. First, electric utilities have adopted cleaner sources of electricity to their mix between the two analysis. Second, electric vehicles have become more efficient, as the average 2013 all-electric vehicle used, representing a 5% improvement over 2011 models. Also, some new models are cleaner than the average, such as the BMW i3, which is rated at 0.27 kWh by the EPA. In states with a cleaner mix generation, the gains were larger. The average all-electric car in California went up to equivalent from in the 2012 study. States with dirtier generation that rely heavily on coal still lag, such as Colorado, where the average BEV only achieves the same emissions as a gasoline-powered car. The author of the 2014 analysis noted that the benefits are not distributed evenly across the U.S. because electric car adoptions is concentrated in the states with cleaner power.
Improving on the UCS analysis and several others, an analysis by economists affiliated with the National Bureau of Economic Research, published in November 2014, estimated marginal emissions of electricity demand that vary by location and time of day across the United States. The marginal analysis, applied to plug-in electric vehicles, found that the emissions of charging PEVs vary by region and hours of the day. In some regions, such as the Western U.S. and Texas, emissions per mile from driving PEVs are less than those from driving a hybrid car. However, in other regions, such as the Upper Midwest, charging during the recommended hours of midnight to 4 a.m. implies that PEVs generate more emissions per mile than the average car currently on the road.
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The results show a tension between electricity load management and environmental goals as the hours when electricity is the least expensive to produce tend to be the hours with the greatest emissions. This occurs because coal-fired plants, which have higher emission rates, are most commonly used to meet base-level and off-peak electricity demand; while natural gas plants, which have relatively low emissions rates, are often brought online to meet peak demand.
In November 2015, the Union of Concerned Scientists published a new report comparing two battery electric vehicles with similar gasoline vehicles by examining their global warming emissions over their full life-cycle, cradle-to-grave analysis. The two BEVs modeled, midsize and full-size, are based on the two most popular BEV models sold in the United States in 2015, the Nissan LEAF and the Tesla Model S. The study found that all-electric cars representative of those sold today, on average produce less than half the global warming emissions of comparable gasoline-powered vehicles, despite higher emissions of manufacture. Considering the regions where the two most popular electric cars are being sold, excess manufacturing emissions are offset within 6 to 16 months of average driving. The study also concluded that driving an average EV results in lower global warming emissions than driving a gasoline car that gets in regions covering two-thirds of the U.S. population, up from 45% in 2009. Based on where EVs are sold in the U.S. in 2015, the average EV produces global warming emissions equal to a gasoline vehicle with a fuel economy rating. The authors identified two main reasons for this reduction since the 2012 study. Electricity generation has become cleaner, as coal-fired generation has declined while lower-carbon alternatives have increased. In addition, electric cars are becoming more efficient. For example, the Nissan Leaf and the Chevrolet Volt, have undergone efficiency improvements to the original 2010 models, and other, more efficient BEV models, such as the most lightweight and efficient BMW i3, have entered the market.
Since then, the UCS has updated their study twice: once in 2017, and yet again in 2018. According to their last report:
"Based on data on power plant emissions released in February 2018, driving on electricity is cleaner than gasoline for most drivers in the US. Seventy-five percent of people now live in places where driving on electricity is cleaner than a 50 MPG gasoline car. And based on where people have already bought EVs, electric vehicles now have greenhouse gas emissions equal to an 80 MPG car, much lower than any gasoline-only car available."

Germany

In a worst-case scenario where incremental electricity demand would be met exclusively with coal, a 2009 study conducted by the World Wide Fund for Nature and IZES found that a mid-size EV would emit roughly, compared with an average of for a gasoline-powered compact car. This study concluded that introducing 1 million EV cars to Germany would, in that scenario, only reduce emissions by 0.1%, if nothing was done to upgrade the electricity infrastructure or manage demand. A more reasonable estimate, relaxing the coal assumption, was provided by Massiani and Weinmann taking into account that the source of energy used for electricity generation would be determined based on the temporal pattern of the additional electricity demand. Their conclusion was that natural gas would provide most of the energy used to reload EV, while renewable energy will not represent more than a few percent of the energy used.
Both these assumptions have proved pessimistic, in 2014 in Germany, 28 percent of electricity generation was from renewable sources in Germany, while by 2018 this fraction was 37%. Some months in 2019 have seen more than 50% of all generation from renewable sources and is expected to rise further as coal generation is first used only for standby and slowly phased out.
In 2014 Volkswagen conducted a life-cycle assessment of its electric vehicles certified by an independent inspection agency. The study found that emissions during the use phase of its all-electric VW e-Golf are 99% lower than those of the Golf 1.2 TSI when the electricity comes from exclusively hydroelectricity generated in Germany, Austria and Switzerland. Accounting for the electric car entire life-cycle, the e-Golf reduces emissions by 61%. When a more realistic EU-27 mix of electricity sources is assumed, with 2014 figures, the e-Golf emissions are still 26% lower than those of the conventional Golf 1.2 TSI.

France

In France, which has many nuclear power plants, emissions from electric car use would be about. Because of the stable nuclear production, the timing of charging electric cars has almost no impact on their environmental footprint.

Norway & Sweden

Since Norway and Sweden produce almost its entire electricity with carbon-free sources, emissions from driving an electric car are even lower, at about in Norway and in Sweden.

Environmental impact of manufacturing

Electric cars also have impacts arising from the manufacturing of the vehicle. Since battery packs are heavy, manufacturers work to lighten the rest of the vehicle. As a result, electric car components contain many lightweight materials that require a lot of energy to produce and process, such as aluminium and carbon-fiber-reinforced polymers. Electric motors and batteries add to the energy of electric-car manufacture. There are two kinds of motors used by electric cars: permanent magnet motors, and induction motors. Induction motors do not use magnets, but permanent magnet motors do. The magnets found in permanent magnet motors used in electric vehicles contain rare-earth metals which are used to increase the power output of these motors. In a study released in 2012, a group of MIT researchers calculated that global mining of two rare-earth metals, neodymium and dysprosium, would need to increase 700% and 2600%, respectively, over the next 25 years to keep pace with various green-tech plans. Substitute strategies introduce trade-offs in efficiency and cost. The same MIT study noted that the materials used in batteries are harmful to the environment. The mining and processing of metals such as lithium, copper, and nickel requires much energy and it can release toxic compounds. In developing countries with weak legislation and/or enforcement thereof, mineral exploitation can increase risks further. As such, the local population may be exposed to toxic substances through air and groundwater contamination. New battery technologies may be needed to resolve those problems. Potential battery technologies that could one day replace Li-ion batteries are the aluminum-ion battery and the sodium-ion battery, but for the moment recycling of these is not any better than the recycling of li-ion batteries. Li-ion batteries recycling is rarely done in developing and developed countries. In fact, in 2017, only just 5% of lithium-ion batteries were actually recycled in the EU.
A report published in June 2011, prepared by Ricardo in collaboration with experts from the UK's Low Carbon Vehicle Partnership, found that hybrid electric cars, plug-in hybrids and all-electric cars generate more carbon emissions during their production than current conventional vehicles, but still have a lower overall carbon footprint over the full life cycle. The higher carbon footprint during production of electric drive vehicles is due mainly to the production of batteries. As an example, 43% of production emissions for a mid-size electric car are generated from the battery production, while for standard mid-sized gasoline internal combustion engine vehicle, around 75% of the embedded carbon emissions during production comes from the steel used in the vehicle glider. The following table summarizes key results of this study for four powertrain technologies:
The Ricardo study also found that the lifecycle carbon emissions for mid-sized gasoline and diesel vehicles are almost identical, and that the greater fuel efficiency of the diesel engine is offset by higher production emissions.
A paper published in 2012 in the Journal of Industrial Ecology named "Comparative environmental life cycle assessment of conventional and electric vehicles" begins by stating that it is important to address concerns of problem-shifting. The study highlighted in particular the toxicity of the electric car's manufacturing process compared to conventional petrol/diesel cars. It concludes that the global warming potential of the process used to make electric cars is twice that of conventional cars. The study also finds that electric cars do not make sense if the electricity they consume is produced predominately by coal-fired power plants. However, the study was later corrected by the authors due to overstating the environmental damage of electric vehicles; many of the electric vehicle components had been incorrectly modelled, and the European power grids were cleaner in many respects than the paper had assumed. A 2018 report by ADAC came to somewhat similar conclusions, stating that "no powertrain has the best climate balance, and the electric car is not always particularly climate-friendly compared to the internal combustion engine car. At its website, ADAC mentions that a big problem in Germany is the fact that much of the produced electricity comes from coal-fired power plants, and that electric cars are only climate-friendly when equipped with regeneration.
Several reports have found that hybrid electric vehicles, plug-in hybrids and all-electric cars generate more carbon emissions during their production than current conventional vehicles. Study of electric car production in Malaysia estimated a compact electric car production release 5,791 kg per unit against conventional vehicles 4,166 kg, but still have a lower overall carbon footprint over the full life cycle. The initial higher carbon footprint is due mainly to battery production.
In February 2014, the Automotive Science Group published the result of a study conducted to assess the life-cycle of over 1,300 automobiles across nine categories sold in North America. The study found that among advanced automotive technologies, the Nissan Leaf holds the smallest life-cycle environmental footprint of any model year 2014 automobile available in the North American market with at least four-person occupancy. The study concluded that the increased environmental impacts of manufacturing the battery electric technology is more than offset with increased environmental performance during operational life. For the assessment, the study used the average electricity mix of the U.S. grid in 2014.
In 2016, the report "Comparative life cycle assessment of hydrogen, methanol and electric vehicles from well to wheel" mentioned that electric vehicles yield higher human toxicity values due to the respective manufacturing and maintenance stages. Since the energy density of hydrogen is quite higher than methanol, hydrogen driven vehicles result in a more environmentally-benign option with respect to global warming and ozone layer depletion potentials.
In 2017, a report made by IVL Swedish Environmental Research Institute also calculated that the emissions of lithium-ion batteries are in the order of 150–200 kilos of carbon dioxide equivalents per kilowatt-hour battery. Half of the emissions comes from cell manufacturing, whereas mining and refining contributes only a small part of the emissions. In practice, emissions in the order of 150–200 kilos of carbon dioxide equivalents per kilowatt-hour means that an electric car with a 100kWh battery will thus have emitted 15–20 tons of carbon dioxide even before the vehicle ignition is turned on. One of the authors, Mats-Ola Larsson, reportedly said that this is the same amount of emissions as driving a gasoline car for 8,2 years. However, Popular Mechanics calculates that even if the 15–20 tons estimate is correct, it would only take 2.4 years of driving for the electric car with a 100kWh battery to recover the greenhouse emissions from the battery manufacturing. Furthermore, two other studies suggest a 100kWh battery would generate about 6-6.4 tons of emissions, so significantly less than what the IVL study claims..
However, in December 2019, IVL Swedish Environmental Research Institute updated their 2017 study, reducing their estimate to 61-106 kgCO2-eq per kWh of battery capacity, with potential to go even lower. The new study therefore shows carbon emissions from battery production are 2-3 times less intensive than previously reported, questioning studies that had taken the 2017 figure to prove EV were not better than ICE cars on life-cycle assessments. Citing the 2019 study:
"The apparent decrease in total GWP from the 2017 report to 61-106kg CO2-eq/kWh battery capacity is partly due to that this report includes battery production with nearly fossil free electricity use which is the main reason for the decrease in the lowest value. The lowering of the high value is mainly due to improved efficiency in cell production. Another reason for a decrease is that the emissions from recycling are not included in the new range. They were about 15kg CO2-eq/kWh battery capacity in the 2017 report."

Raw material availability and supply security

Common technology for plug-in hybrids and electric cars is based on the lithium-ion battery and an electric motor which uses rare-earth elements. The demand for lithium and other specific elements 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., the Toyota Prius battery contains more than of the rare-earth element lanthanum, and its motor magnets use neodymium and dysprosium. While only of lithium carbonate equivalent are required in a smartphone and in a tablet computer, electric vehicles and stationary energy storage systems for homes, businesses or industry use much more lithium in their batteries. a hybrid electric passenger car might use of LCE, while one of Tesla's high performance electric cars could use as much as.
Some of the largest world reserves of lithium and rare-earth 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.
;Lithium
in Bolivia is one of the largest known lithium reserves in the world.
The main deposits of lithium are found in China and throughout the Andes mountain chain in South America. In 2008 Chile was the leading lithium metal producer with almost 30%, followed by China, Argentina, and Australia. In the United States lithium is recovered from brine pools in Nevada.
Nearly half the world's known reserves are located in Bolivia, and according to the US Geological Survey, Bolivia's Salar de Uyuni desert has 5.4 million tons of lithium. Other important reserves are located in Chile, China, and Brazil. Since 2006 the Bolivian government have nationalized oil and gas projects and is keeping a tight control over mining its lithium reserves. Already the Japanese and South Korean governments, as well as companies from these two countries and France, have offered technical assistance to develop Bolivia's lithium reserves and are seeking to gain access to the lithium resources through a mining and industrialization model suitable to Bolivian interests.
According to a 2011 study conducted at Lawrence Berkeley National Laboratory and the University of California Berkeley, the currently estimated reserve base of lithium should not be a limiting factor for large-scale battery production for electric vehicles, as the study estimated that on the order of 1 billion 40 kWh Li-based batteries could be built with current reserves, as estimated by the U.S. Geological Survey. Another 2011 study by researchers from the University of Michigan and Ford Motor Company found that there are sufficient lithium resources to support global demand until 2100, including the lithium required for the potential widespread use of hybrid electric, plug-in hybrid electric and battery electric vehicles. The study estimated global lithium reserves at 39 million tons, and total demand for lithium during the 90-year period analyzed at 12–20 million tons, depending on the scenarios regarding economic growth and recycling rates.
A 2016 study by Bloomberg New Energy Finance found that availability of lithium and other finite materials used in the battery packs will not be a limiting factor for the adoption of electric vehicles. BNEF estimated that battery packs will require less than 1% of the known reserves of lithium, nickel, manganese, and copper through 2030, and 4% of the world's cobalt. After 2030, the study states that new battery chemistries will probably shift to other source materials, making packs lighter, smaller, and cheaper.
;Rare-earth elements
China has 48% of the world's reserves of rare-earth elements, the United States has 13%, and Russia, Australia, and Canada have significant deposits. Until the 1980s, the U.S. led the world in rare-earth production, but since the mid-1990s China has controlled the world market for these elements. The mines in Bayan Obo near Baotou, Inner Mongolia, are currently the largest source of rare-earth metals and are 80% of China's production. In 2010 China accounted for 97% of the global production of 17 rare-earth elements. Since 2006 the Chinese government has been imposing export quotas reducing supply at a rate of 5% to 10% a year.
Prices of several rare-earth elements increased sharply by mid-2010 as China imposed a 40% export reduction, citing environmental concerns as the reason for the export restrictions. These quotas have been interpreted as an attempt to control the supply of rare-earths. However, the high prices have provided an incentive to begin or reactivate several rare-earth mining projects around the world, including the United States, Australia, Vietnam, and Kazakhstan.
oxides production by country
In September 2010, China temporarily blocked all exports of rare-earths to Japan in the midst of a diplomatic dispute between the two countries. These minerals are used in hybrid cars and other products such wind turbines and guided missiles, thereby augmenting the worries about the dependence on Chinese rare-earth elements and the need for geographic diversity of supply. A December 2010 report published by the US DoE found that the American economy vulnerable to rare-earth shortages and estimates that it could take 15 years to overcome dependence on Chinese supplies. China raised export taxes for some rare-earths from 15 to 25%, and also extended taxes to exports of some rare-earth alloys that were not taxed before. The Chinese government also announced further reductions on its export quotas for the first months of 2011, which represent a 35% reduction in tonnage as compared to exports during the first half of 2010.
On September 29, 2010, the U.S. House of Representatives approved the Rare Earths and Critical Materials Revitalization Act of 2010. The approved legislation is aimed at restoring the U.S. as a leading producer of rare-earth elements, and would support activities in the U.S. Department of Energy to discover and develop rare-earth sites inside of the U.S. in an effort to reduce the auto industry's near-complete dependence on China for the minerals. A similar bill, the Rare Earths Supply Technology and Resources Transformation Act of 2010, is being discussed in the U.S. Senate.
In order to avoid its dependence on rare-earth minerals, Toyota Motor Corporation announced in January 2011 that it is developing an alternative motor for future hybrid and electric cars that does not need rare-earth materials. Toyota engineers in Japan and the U.S. are developing an induction motor that is lighter and more efficient than the magnet-type motor used in the Prius, which uses two rare-earths in its motor magnets. Other popular hybrids and plug-in electric cars in the market that use these rare-earth elements are the Nissan Leaf, the Chevrolet Volt and Honda Insight. For its second generation RAV4 EV due in 2012, Toyota is using an induction motor supplied by Tesla Motors that does not require rare-earth materials. The Tesla Roadster and the Tesla Model S use a similar motor.

Less dependence on imported oil

Through the gradual replacement of internal combustion engine vehicles for electric cars and plug-in hybrids, electric drive vehicles can contribute significantly to lessen the dependence of the transport sector on imported oil as well as contributing to the development of a more resilient energy supply, with the associated environmental benefits.
For many net oil importing countries the 2000s energy crisis brought back concerns first raised during the 1973 oil crisis. For the United States, the other developed countries and emerging countries their dependence on foreign oil has revived concerns about their vulnerability to price shocks and supply disruption. Also, there have been concerns about the uncertainty surrounding peak oil production and the higher cost of extracting unconventional oil. A third issue that has been raised is the threat to national security because most proven oil reserves are concentrated in relatively few geographic locations, including some countries with strong resource nationalism, unstable governments or hostile to U.S. interests. In addition, for many developing countries, and particularly for the poorest African countries, high oil prices have an adverse impact on the government budget and deteriorate their terms of trade thus jeopardizing their balance of payments, all leading to lower economic growth.