Alternative fuel vehicle
An alternative fuel vehicle is a motor vehicle that runs on alternative fuel rather than traditional petroleum-based fossil fuels such as gasoline, petrodiesel or liquefied petroleum gas (autogas). The term typically refers to internal combustion engine vehicles or fuel cell vehicles that utilize synthetic renewable fuels such as biofuels (ethanol fuel, biodiesel and biogasoline), hydrogen fuel or so-called "Electrofuel". The term can also be used to describe an electric vehicle (particularly a battery electric vehicle or a solar vehicle), which should be more appropriately called an "alternative energy vehicle" or "new energy vehicle" as its propulsion actually relies on electricity rather than motor fuel.
Vehicle engines powered by gasoline/petrol first emerged in the 1860s and 1870s; they took until the 1930s to completely dominate the original "alternative" engines driven by steam (18th century), by gases (early 19th century), or by electricity (c. 1830s). Because of a combination of factors, such as environmental and health concerns including climate change and air pollution, high oil-prices and the potential for peak oil, development of cleaner alternative fuels and advanced power systems for vehicles has become a high priority for many governments and vehicle manufacturers around the world in recent years.
Hybrid electric vehicles such as the Toyota Prius are not actually alternative fuel vehicles, as they still use traditional fuels such as gasoline, but through advancement in electric battery/supercapacitor and motor–generator technologies, they have an overall better fuel efficiency than conventional combustion vehicles.[2] Other research and development efforts in alternative forms of power focus on developing plug-in electric, range extender and fuel cell vehicles, and even compressed-air vehicles.
An environmental analysis of the impacts of various vehicle-fuels extends beyond just operating efficiency and emissions, especially if a technology comes into wide use. A life-cycle assessment of a vehicle involves production and post-use considerations. In general, the lifecycle greenhouse gas emissions of battery-electric vehicles are lower than emissions from hydrogen, PHEV, hybrid, compressed natural gas, gasoline, and diesel vehicles.[3]
Current deployments
[edit]As of 2019[update], there were more than 1.49 billion motor vehicles on the world's roads,[4] compared with approximately 159 million alternative fuel and advanced technology vehicles that had been sold or converted worldwide at the end of 2022 and consisting of:
- Over 65 million flex fuel automobiles, motorcycles and light duty trucks by the end of 2021, led by Brazil with 38.3 million[5] and the United States with 27 million.[6]
- Over 26 million plug-in electric vehicles, 70% of which were battery electric vehicles (BEVs) and 30% of which were plug-in hybrids (PHEVs).[7] China had 13.8 million units, Europe 7.8 million, and the United States 3 million.[7] In 2022, annual sales exceeded 10 million vehicles, up 55% relative to 2021.[8]
- 24.9 million LPG powered vehicles by December 2013, led by Turkey with 3.93 million, South Korea (2.4 million), and Poland (2.75 million).[9]
- 24.5 million natural gas vehicles by the end of 2017, led by China (5.35 million) followed by Iran (4.0 million), India (3.05 million), Pakistan (3 million), Argentina (2.3 million), and Brazil (1.78 million).[10] In 2015, 2.4 million units were sold.[11]
- Over 13 million hybrid electric vehicles as of 2019.[12]
- 5.7 million neat-ethanol only light-vehicles built in Brazil since 1979,[13] with 2.4 to 3.0 million vehicles still in use by 2003.[14][15] and 1.22 million units as of December 2011.[16]
- 70,200 fuel cell electric vehicles (FCEVs) powered with hydrogen by the end of 2022.[3] South Korea had 29,500 units, the United States 15,000, China 11,200, and Japan 7,700.[3] In 2022, annual sales amounted to 15,391 vehicles.[17] Hydrogen FCEV sales as a percentage of market share among electric vehicles (BEVs, PHEVs and FCEVs) declined for the 6th consecutive year.[3]
Mainstream commercial technologies
[edit]Flexible fuel
[edit]
A flexible-fuel vehicle (FFV) or dual-fuel vehicle (DFF) is an alternative fuel automobile or light duty truck with a multifuel engine that can use more than one fuel, usually mixed in the same tank, and the blend is burned in the combustion chamber together. These vehicles are colloquially called flex-fuel, or flexifuel in Europe, or just flex in Brazil. FFVs are distinguished from bi-fuel vehicles, where two fuels are stored in separate tanks. The most common commercially available FFV in the world market is the ethanol flexible-fuel vehicle, with the major markets concentrated in the United States, Brazil, Sweden, and some other European countries.
Ethanol flexible-fuel vehicles have standard gasoline engines that are capable of running with ethanol and gasoline mixed in the same tank. These mixtures have "E" numbers which describe the percentage of ethanol in the mixture, for example, E85 is 85% ethanol and 15% gasoline. (See common ethanol fuel mixtures for more information.) Though technology exists to allow ethanol FFVs to run on any mixture up to E100,[18][19] in the U.S. and Europe, flex-fuel vehicles are optimized to run on E85. This limit is set to avoid cold starting problems during very cold weather.
Over 65 million flex fuel automobiles, motorcycles and light duty trucks by the end of 2021, led by Brazil with 38.3 million[5] and the United States with 27 million.[6] Other markets were Canada (1.6 million by 2014),[20] and Sweden (243,100 through December 2014).[21][22][23] The Brazilian flex fuel fleet includes over 4 million flexible-fuel motorcycles produced since 2009 through March 2015.[24] In Brazil, 65% of flex-fuel car owners were using ethanol fuel regularly in 2009,[25] while, the actual number of American FFVs being run on E85 is much lower; surveys conducted in the U.S. have found that 68% of American flex-fuel car owners were not aware they owned an E85 flex.[18]
There have been claims that American automakers are motivated to produce flex-fuel vehicles due to a loophole in the Corporate Average Fuel Economy (CAFE) requirements, which gives the automaker a "fuel economy credit" for every flex-fuel vehicle sold, whether or not the vehicle is actually fueled with E85 in regular use.[26] This loophole allegedly allows the U.S. auto industry to meet CAFE fuel economy targets not by developing more fuel-efficient models, but by spending between US$100 and US$200 extra per vehicle to produce a certain number of flex-fuel models, enabling them to continue selling less fuel-efficient vehicles such as SUVs, which netted higher profit margins than smaller, more fuel-efficient cars.[27][28]
Plug-in electric
[edit]Battery-electric
[edit] | This section needs more citations. (September 2008) |
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Battery electric vehicles (BEVs), also known as all-electric vehicles (AEVs), are electric vehicles whose main energy storage is in the chemical energy of batteries. BEVs are the most common form of what is defined by the California Air Resources Board (CARB) as zero emission vehicle (ZEV) because they produce no tailpipe emissions at the point of operation. The electrical energy carried on board a BEV to power the motors is obtained from a variety of battery chemistries arranged into battery packs. For additional range genset trailers or pusher trailers are sometimes used, forming a type of hybrid vehicle. Batteries used in electric vehicles include "flooded" lead-acid, absorbed glass mat, NiCd, nickel metal hydride, Li-ion, Li-poly and zinc-air batteries.
Attempts at building viable, modern battery-powered electric vehicles began in the 1950s with the introduction of the first modern (transistor controlled) electric car – the Henney Kilowatt, even though the concept was out in the market since 1890. Despite the poor sales of the early battery-powered vehicles, development of various battery-powered vehicles continued through the mid-1990s, with such models as the General Motors EV1 and the Toyota RAV4 EV.
Battery powered cars had primarily used lead-acid batteries and NiMH batteries. Lead-acid batteries' recharge capacity is considerably reduced if they're discharged beyond 75% on a regular basis, making them a less-than-ideal solution. NiMH batteries are a better choice[citation needed], but are considerably more expensive than lead-acid. Lithium-ion battery powered vehicles such as the Venturi Fetish and the Tesla Roadster have recently demonstrated excellent performance and range, and nevertheless is used in most mass production models launched since December 2010.
Expanding on traditional lithium-ion batteries predominately used in today's battery electric vehicles, is an emerging science that is paving the way to utilize a carbon fiber structure (a vehicle body or chassis in this case) as a structural battery. Experiments being conducted at the Chalmers University of Technology in Sweden are showing that when coupled with Lithium-ion insertion mechanisms, an enhanced carbon fiber structure can have electromechanical properties. This means that the carbon fiber structure itself can act as its own battery/power source for propulsion. This would negate the need for traditional heavy battery banks, reducing weight and therefore increasing fuel efficiency.[30]
As of December 2015[update], several neighborhood electric vehicles, city electric cars and series production highway-capable electric cars and utility vans have been made available for retails sales, including Tesla Roadster, GEM cars, Buddy, Mitsubishi i MiEV and its rebadged versions Peugeot iOn and Citroën C-Zero, Chery QQ3 EV, JAC J3 EV, Nissan Leaf, Smart ED, Mia electric, BYD e6, Renault Kangoo Z.E., Bolloré Bluecar, Renault Fluence Z.E., Ford Focus Electric, BMW ActiveE, Renault Twizy, Tesla Model S, Honda Fit EV, RAV4 EV second generation, Renault Zoe, Mitsubishi Minicab MiEV, Roewe E50, Chevrolet Spark EV, Fiat 500e, BMW i3, Volkswagen e-Up!, Nissan e-NV200, Volkswagen e-Golf, Mercedes-Benz B-Class Electric Drive, Kia Soul EV, BYD e5, and Tesla Model X.[31] The world's all-time top selling highway legal electric car is the Nissan Leaf, released in December 2010, with global sales of more than 250,000 units through December 2016.[32] The Tesla Model S, released in June 2012, ranks second with global sales of over 158,000 cars delivered as of December 2016[update].[32] The Renault Kangoo Z.E. utility van is the leader of the light-duty all-electric segment with global sales of 25,205 units through December 2016.[33]
Plug-in hybrid
[edit]
Plug-in hybrid electric vehicles (PHEVs) use batteries to power an electric motor, as well as another fuel, such as gasoline or diesel, to power an internal combustion engine or other propulsion source. PHEVs can charge their batteries through charging equipment and regenerative braking. Using electricity from the grid to run the vehicle some or all of the time reduces operating costs and fuel use, relative to conventional vehicles.[35]
Until 2010 most plug-in hybrids on the road in the U.S. were conversions of conventional hybrid electric vehicles,[36] and the most prominent PHEVs were conversions of 2004 or later Toyota Prius, which have had plug-in charging and more batteries added and their electric-only range extended.[37] Chinese battery manufacturer and automaker BYD Auto released the F3DM to the Chinese fleet market in December 2008[38][39][40] and began sales to the general public in Shenzhen in March 2010.[41][42] General Motors began deliveries of the Chevrolet Volt in the U.S. in December 2010.[43] Deliveries to retail customers of the Fisker Karma began in the U.S. in November 2011.
During 2012, the Toyota Prius Plug-in Hybrid, Ford C-Max Energi, and Volvo V60 Plug-in Hybrid were released. The following models were launched during 2013 and 2015: Honda Accord Plug-in Hybrid, Mitsubishi Outlander P-HEV, Ford Fusion Energi, McLaren P1 (limited edition), Porsche Panamera S E-Hybrid, BYD Qin, Cadillac ELR, BMW i3 REx, BMW i8, Porsche 918 Spyder (limited production), Volkswagen XL1 (limited production), Audi A3 Sportback e-tron, Volkswagen Golf GTE, Mercedes-Benz S 500 e, Porsche Cayenne S E-Hybrid, Mercedes-Benz C 350 e, BYD Tang, Volkswagen Passat GTE, Volvo XC90 T8, BMW X5 xDrive40e, Hyundai Sonata PHEV, and Volvo S60L PHEV.
As of December 2015[update], about 500,000 highway-capable plug-in hybrid electric cars had been sold worldwide since December 2008, out of total cumulative global sales of 1.2 million light-duty plug-in electric vehicles.[44] As of December 2016[update], the Volt/Ampera family of plug-in hybrids, with combined sales of about 134,500 units is the top selling plug-in hybrid in the world. Ranking next are the Mitsubishi Outlander P-HEV with about 119,500, and the Toyota Prius Plug-in Hybrid with almost 78,000.[1]
Biofuels
[edit]Bioalcohol and ethanol
[edit]The first commercial vehicle that used ethanol as a fuel was the Ford Model T, produced from 1908 through 1927. It was fitted with a carburetor with adjustable jetting, allowing use of gasoline or ethanol, or a combination of both.[45][46][47] Other car manufactures also provided engines for ethanol fuel use.[18] In the United States, alcohol fuel was produced in corn-alcohol stills until Prohibition criminalized the production of alcohol in 1919. The use of alcohol as a fuel for internal combustion engines, either alone or in combination with other fuels, lapsed until the oil price shocks of the 1970s. Furthermore, additional attention was gained because of its possible environmental and long-term economical advantages over fossil fuel.
Both ethanol and methanol have been used as an automotive fuel.[48] While both can be obtained from petroleum or natural gas, ethanol has attracted more attention because it is considered a renewable resource, easily obtained from sugar or starch in crops and other agricultural produce such as grain, sugarcane, sugar beets or even lactose. Since ethanol occurs in nature whenever yeast happens to find a sugar solution such as overripe fruit, most organisms have evolved some tolerance to ethanol, whereas methanol is toxic. Other experiments involve butanol, which can also be produced by fermentation of plants. Support for ethanol comes from the fact that it is a biomass fuel, which addresses climate change and greenhouse gas emissions, though these benefits are now highly debated,[18][49][50][51] including the heated 2008 food vs fuel debate.
Most modern cars are designed to run on gasoline are capable of running with a blend from 10% up to 15% ethanol mixed into gasoline (E10-E15). With a small amount of redesign, gasoline-powered vehicles can run on ethanol concentrations as high as 85% (E85), the maximum set in the United States and Europe due to cold weather during the winter,[52] or up to 100% (E100) in Brazil, with a warmer climate. Ethanol has close to 34% less energy per volume than gasoline,[53][54] consequently fuel economy ratings with ethanol blends are significantly lower than with pure gasoline, but this lower energy content does not translate directly into a 34% reduction in mileage, because there are many other variables that affect the performance of a particular fuel in a particular engine, and also because ethanol has a higher octane rating which is beneficial to high compression ratio engines.
For this reason, for pure or high ethanol blends to be attractive for users, its price must be lower than gasoline to offset the lower fuel economy. As a rule of thumb, Brazilian consumers are frequently advised by the local media to use more alcohol than gasoline in their mix only when ethanol prices are 30% lower or more than gasoline, as ethanol price fluctuates heavily depending on the results and seasonal harvests of sugar cane and by region.[55][56] In the US, and based on EPA tests for all 2006 E85 models, the average fuel economy for E85 vehicles was found 25.56% lower than unleaded gasoline.[18] The EPA-rated mileage of current American flex-fuel vehicles[57] could be considered when making price comparisons, though E85 has octane rating of about 104 and could be used as a substitute for premium gasoline. Regional retail E85 prices vary widely across the US, with more favorable prices in the Midwest region, where most corn is grown and ethanol produced. In August 2008 the US average spread between the price of E85 and gasoline was 16.9%, while in Indiana was 35%, 30% in Minnesota and Wisconsin, 19% in Maryland, 12 to 15% in California, and just 3% in Utah.[58] Depending on the vehicle capabilities, the break even price of E85 usually has to be between 25 and 30% lower than gasoline.[18]
Reacting to the high price of oil and its growing dependence on imports, in 1975 Brazil launched the Pro-alcool program, a huge government-subsidized effort to manufacture ethanol fuel (from its sugar cane crop) and ethanol-powered automobiles. These ethanol-only vehicles were very popular in the 1980s, but became economically impractical when oil prices fell – and sugar prices rose – late in that decade. In May 2003 Volkswagen built for the first time a commercial ethanol flexible fuel car, the Gol 1.6 Total Flex. These vehicles were a commercial success and by early 2009 nine other Brazilian manufacturers are producing flexible fuel vehicles: Chevrolet, Fiat, Ford, Peugeot, Renault, Honda, Mitsubishi, Toyota, Citroën, and Nissan.[13][59] The adoption of the flex technology was so rapid, that flexible fuel cars reached 87.6% of new car sales in July 2008.[60] As of August 2008, the fleet of "flex" automobiles and light commercial vehicles had reached 6 million new vehicles sold,[61] representing almost 19% of all registered light vehicles.[62] The rapid success of "flex" vehicles, as they are popularly known, was made possible by the existence of 33,000 filling stations with at least one ethanol pump available by 2006, a heritage of the Pro-alcool program.[63][26]
In the United States, initial support to develop alternative fuels by the government was also a response to the 1973 oil crisis, and later on, as a goal to improve air quality. Also, liquid fuels were preferred over gaseous fuels not only because they have a better volumetric energy density but also because they were the most compatible fuels with existing distribution systems and engines, thus avoiding a big departure from the existing technologies and taking advantage of the vehicle and the refueling infrastructure.[48] California led the search of sustainable alternatives with interest in methanol.[48] In 1996, a new FFV Ford Taurus was developed, with models fully capable of running either methanol or ethanol blended with gasoline.[48][64] This ethanol version of the Taurus was the first commercial production of an E85 FFV.[65] The momentum of the FFV production programs at the American car companies continued, although by the end of the 1990s, the emphasis was on the FFV E85 version, as it is today.[48] Ethanol was preferred over methanol because there is a large support in the farming community and thanks to government's incentive programs and corn-based ethanol subsidies.[66] Sweden also tested both the M85 and the E85 flexifuel vehicles, but due to agriculture policy, in the end emphasis was given to the ethanol flexifuel vehicles.[67]
The Ford Model T was the first commercial flex-fuel vehicle. The engine was capable of running on gasoline or ethanol, or a mix of both.
The 1996 Ford Taurus was the first flexible-fuel vehicle produced with versions capable of running with either ethanol (E85) or methanol (M85) blended with gasoline.
The 2003 VW Gol 1.6 Total Flex was the first commercial flexible-fuel vehicle in the Brazilian market, capable of running on any mixture of gasoline (
