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Biofuel · Electric vehicle |
Green vehicle · Plug-in hybrid |
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A green vehicle or environmentally friendly vehicle is a road motor vehicle that produces less harmful impacts to the environment than comparable conventional internal combustion engine vehicles running on gasoline or diesel, or one that uses alternative fuels.[2][3] Presently, in some countries the term is used for any vehicle surpassing the Euro6-norm such as LEVs and ULEVs, and also more informally it is used for California's zero emissions vehicles and other low-carbon emission vehicles.[4]
Green vehicles are powered by alternative fuels and advanced vehicle technologies and include hybrid electric vehicles, plug-in hybrid electric vehicles, battery electric vehicles, compressed-air vehicles, hydrogen and fuel-cell vehicles, neat ethanol vehicles, flexible-fuel vehicles, natural gas vehicles, clean diesel vehicles, and some sources also include vehicles using blends of biodiesel and ethanol fuel or gasohol.[3][5] Several author also include conventional motor vehicles with high fuel economy, as they consider that increasing fuel economy is the most cost-effective way to improve energy efficiency and reduce carbon emissions in the transport sector in the short run.[6] As part of their contribution to sustainable transport, environmentally friendly vehicles reduce air pollution and greenhouse gas emissions, and contribute to energy independence by reducing oil imports.[3][6]
Part of the total energy cost can be cut by choosing smaller, lighter vehicles that use less energy to produce and to operate. Alternatively larger heavier vehicles with more efficient power systems may use less energy overall.
Cars with similar production energy costs can obtain, during the life of the car (operational phase), large reductions in energy costs through several measures:
Comparison of several types of green car basic characteristics (Values are overall for vehicles in current production and may differ between types) |
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---|---|---|---|---|---|
Type of vehicle/ powertrain |
Fuel economy (mpg equivalent) |
Range | Production cost for given range |
Reduction in CO2 compared to conventional |
Payback period |
Conventional ICE | 10-78 | Long (400-600 mi) |
Low | 0% | - |
Biodiesel | 18-71 | Long (360-540 mi) |
Low | 100% | - |
All-electric | Excluding battery cost: 99 Including battery cost: 10-50 |
Shorter (73-150 mi) |
High | varies | - |
Hydrogen fuel cell | 80[7] | High | |||
Hybrid electric | 30-60 | 380 mi[7] | Medium | 5 years[8][9] |
Green vehicles include vehicles types that function fully or partly on alternative energy sources other than fossil fuel or less carbon intensive than gasoline or diesel.
Another option is the use of alternative fuel composition in conventional fossil fuel-based vehicles, making them function partially 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.
Examples of vehicles with reduced petroleum consumption include electric cars, plug-in hybrids and fuel cell-powered hydrogen cars.
Electric cars are typically more efficient than fuel cell-powered vehicles on a wheel-to-wheel basis.[10] For this reason, battery powered vehicles and plug-in hybrids are gaining popularity. They have better fuel economy than conventional internal combustion engine vehicles but are hampered by range or maximum distance attainable before discharging the battery. The electric car batteries are their main cost. They provide a 55% to 99.9% improvement in CO2 emissions compared to an ICE (gasoline, diesel) vehicle, depending on the source of electricity.[11]
Hybrid cars may be partly fossil fueled and partly electric or hydrogen-powered. They are more expensive to purchase but cost redemption is achieved in a period of about 5 years due to better fuel economy.[8][9]
Compressed air cars, stirling-powered vehicles, Liquid nitrogen vehicles are even less polluting than electrical vehicles, as the vehicle and its components can be made more environmentally friendly.
Solar car races are held on a regular basis in order to promote green vehicles and other "green technology". These sleek driver-only vehicles can travel long distances at highway speeds using only the electricity generated instantaneously from the sun.
A conventional vehicle can become a greener vehicle by mixing in renewable fuels or using less carbon intensive fossil fuel. Typical gasoline-powered cars can tolerate up to 10% ethanol. Brazil manufactured cars that run on neat ethanol, though there were discontinued. Another available option is a flexible-fuel vehicle which allows any blend of gasoline and ethanol, up to 85% in North America and Europe, and up to 100% in Brazil.[12] Another existing option is to convert a conventional gasoline-powered to allow the alternative use of CNG. Pakistan, Argentina, Brazil, Iran, India, Italy, and China have the largest fleets of natural gas vehicles in the world.[13]
Diesel-powered vehicles can often transition completely to biodiesel, though the fuel is a very strong solvent, which can occasionally damage rubber seals in vehicles built before 1994. More commonly, however, biodiesel causes problems simply because it removes all of the built-up residue in an engine, clogging filters, unless care is taken when switching from dirty fossil-fuel derived diesel to bio-diesel. It is very effective at 'de-coking' the diesel engines combustion chambers and keeping them clean. Biodiesel is the lowest emission fuel available for diesel engines. Diesel engines are the most efficient car internal combustion engines. Biodiesel is the only fuel allowed in some North American national parks because spillages will completely bio-degrade within 21 days. Biodiesel and vegetable oil fuelled, diesel engined vehicles have been declared amongst the greenest in the US Tour de Sol competition.
This presents a problem, however, as biofuels can use food resources in order to provide mechanical energy for vehicles. Many experts point to this as a reason for growing food prices, particularly US Bio-ethanol fuel production which has affected maize prices. In order to have a low environmental impact, biofuels should be made only from waste products, or from new sources - like algae.
Horse and carriage are just one type of animal propelled vehicle. Once a common form of transportation, they became far less common as cities grew and automobiles took their place. In dense cities, the waste produced by large numbers of transportation animals was a significant health problem. Oftentimes the food is produced for them using diesel powered tractors, and thus there is some environmental impact as a result of their use.
Human powered transport includes walking, bicycles, velomobiles, row boats, and other environmentally friendly ways of getting around. In addition to the health benefits of the exercise provided, they are far more environmentally friendly than most other options. The only downside is the speed limitations, and how far one can travel before getting exhausted.
A study by CNW Marketing Research suggests that the extra energy cost of manufacture, shipping, disposal, and the short lives of some of these types of vehicle (particularly gas-electric hybrid vehicles) outweighs any energy savings made by their using less petroleum during their useful lifespan.[14] Critics of the report note that the study prorated all of Toyota's hybrid research-and-development costs across the relatively small number of Priuses on the road, rather than using the incremental cost of building a vehicle; used 109,000 miles (175,000 km) for the length of life of a Prius (Toyota offers a 150,000-mile (240,000 km) warranty on the Prius' hybrid components, including the battery), and calculated that a majority of a car's cradle-to-grave energy gets expended during the vehicle's production, not while it is driven.[15]
Norwegian Consumer Ombudsman official Bente Øverli stated that "Cars cannot do anything good for the environment except less damage than others." Based on this opinion, Norwegian law severely restricts the use of "greenwashing" to market automobiles, strongly prohibiting advertising a vehicle as being environmentally friendly, with large fines issued to violators.[16][17][18][19]
Vehicle emissions contribute to the increasing concentration of gases linked to climate change.[20] In order of significance, the principal greenhouse gases associated with road transport are carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O).[21] Road transport is the third largest source of greenhouse gases emitted in the UK, and accounts for over 20% of total emissions,[22] and 33% in the United States.[23] Of the total greenhouse gas emissions from transport, over 85% are due to CO2 emissions from road vehicles. The transport sector is the fastest growing source of greenhouse gases.[24]
Vehicle pollutants have been linked to human ill health including the incidence of respiratory and cardiopulmonary disease and lung cancer. A 1998 report estimated that up to 24,000 people die prematurely each year in the UK as a direct result of air pollution.[25] According to the World Health Organisation, up to 13,000 deaths per year among children (aged 0–4 years) across Europe are directly attributable to outdoor pollution. The organisation estimates that if pollution levels were returned to within EU limits, more than 5,000 of these lives could be saved each year.
Hybrid taxi fleet operators in New York have also reported that reduced fuel consumption saves them thousands of dollars per year.[26]
The European Union is promoting the marketing of greener cars via a combination of binding and non-binding measures.[27] As of April 2010, 15 of the 27 European Union member states provide tax incentives for electrically chargeable vehicles and some alternative fuel vehicles, which includes all Western European countries except Italy and Luxembourg, plus the Czech Republic and Romania. The incentives consist of tax reductions and exemptions, as well as of bonus payments for buyers of electric cars, plug-in hybrids, hybrid electric vehicles and natural gas vehicles.[28][29]
The United States Environmental Protection Agency (EPA) is promoting the marketing of greener cars via the SmartWay program. The SmartWay and SmartWay Elite designation mean that a vehicle is a better environmental performer relative to other vehicles. This US EPA designation is arrived at by taking into account a vehicle's Air Pollution Score and Greenhouse Gas Score. Higher Air Pollution Scores indicate vehicles that emit lower amounts of pollutants that cause smog relative to other vehicles. Higher Greenhouse Gas Scores indicate vehicles that emit lower amounts of carbon dioxide and have improved fuel economy relative to other vehicles.
To earn the SmartWay designation, a vehicle must earn at least a 6 on the Air Pollution Score and at least a 6 on the Greenhouse Gas Score, but have a combined score of at least 13. SmartWay Elite is given to those vehicles that score 9 or better on both the Greenhouse Gas and Air Pollution Scores.
A Green Vehicle Marketing Alliance, in conjunction with the Oak Ridge National Laboratory (ONRL), periodically meets, and coordinates marketing efforts.[30]
The Progressive Insurance Automotive X PRIZE (PIAXP) is a set of competitions, programs and events, from the X PRIZE Foundation to "inspire a new generation of super-efficient vehicles that help break America's addiction to oil and stem the effects of climate change."[31] Progressive Insurance is the title sponsor of the prize, the centerpiece of which is the Competition Division, within which a $10 million dollar purse will be divided between the winners of three competitions.
The essence of each competition is to design, build and race super-efficient vehicles that will achieve 100 MPGe (2.35 liter/100 kilometer) and can be produced for the mass market.[32] Within the Competition Division, there are two vehicle classes: Mainstream and Alternative. The mainstream class has a prize of $5 million. The alternate class has 2 separate prizes of $2.5 million, one for side-by-side seating and one for tandem seating.[33]
Some of the competitors, such as Aptera and Tesla, are already taking deposits for 'green' vehicles from customers.
Several automobile magazines, motor vehicle specialized publications and environmental groups publish annual rankings or listings of the best green cars of a given year. The following table presents a selection of the annual top pickings.
Selected annual rankings of green cars | |||||
---|---|---|---|---|---|
Vehicle | Year model |
Type of vehicle/fuel |
EPA Combined mileage (mpg) |
EPA City mileage (mpg) |
EPA Highway mileage (mpg) |
Most efficient EPA-certified vehicles[34] | |||||
Toyota Prius — Current year, gasoline fuel | 2011 | Hybrid electric | 50 | 51 | 48 |
Honda Insight — All years, gasoline fuel | 2000 | Hybrid electric | 53 | 49 | 61 |
Mitsubishi i-MiEV — All years, all fuels | 2012 | Electric car | 112 mpg-e | 126 mpg-e | 99 mpg-e |
Green Car Journal — Green Car of the Year | |||||
Honda Civic GX — 2012 Award[35] | 2012 | Natural gas | 28 | 24 | 36 |
Chevrolet Volt — 2011 Award[36][37][38] | 2011 | Plug-in hybrid | Gas equivalent All-electric mode |
Gasoline only mode |
All-electric range |
93 mpg-e | 37 mpg | 35 mi | |||
Audi A3 TDI — 2010 Award[39] | 2010 | Clean diesel | 33 | 30 | 41 |
VW Jetta TDI — 2009 Award[40] | 2009 | Clean diesel | 41 | 40 | 43 |
Green Car Journal — Green Car Vision Award | |||||
Ford Focus Electric — 2011 Award[41] | 2012 | Electric car | Gasoline equivalent fuel economy |
All-electric range | |
|
100 mi | ||||
Nissan Leaf — 2010 Award[42][43] | 2011 | Electric car | Gasoline equivalent fuel economy |
All-electric range | |
99 mpg-e | 73 mi | ||||
Chevrolet Volt — 2009 Award[37][38][44] | 2011 | Plug-in hybrid | Gas equivalent All-electric mode |
Gasoline only mode |
All-electric range |
93 mpg-e | 37 mpg | 35 mi | |||
World Car of the Year — World Green Car | |||||
Chevrolet Volt — 2011 Award[45] | 2011 | Plug-in hybrid | Gas equivalent All-electric mode |
Gasoline only mode |
All-electric range |
93 mpg-e | 37 mpg | 35 mi | |||
Volkswagen BlueMotion — 2010 Award[46] (Golf, Passat, Polo) |
2010 | Clean diesel | n.a. | n.a. | n.a. |
Honda FCX Clarity — 2009 Award[47] (miles per kilogram of hydrogen) |
2009 | Hydrogen fuel cell | 77 | 67 | 72 |
Consumer Reports Top Picks: Green Car Category | |||||
Toyota Prius — Best model 2010[48] | 2010 | Hybrid electric | 50 | 51 | 48 |
Toyota Prius — Best model 2009[49] | 2009 | Hybrid electric | 46 | 48 | 45 |
Consumer Reports American Top Picks: Green Car Category | |||||
Ford Fusion Hybrid — Top Pick 2010[50] | 2010 | Hybrid electric | 39 | 41 | 36 |
Ford Escape Hybrid — Top Pick 2009[51] | 2009 | Hybrid electric | 32 | 34 | 31 |
What Car? Green Awards | |||||
Toyota Auris Hybrid — Overall Winner 2010[52] | 2010 | Hybrid electric | UK combined 74 mpg-imp (3.8 L/100 km; 62 mpg-US)[52] | ||
Volvo S40 1.6D DRIVe S — Overall Winner 2009[53] | 2009 | Clean diesel | UK combined 60 mpg-imp (4.7 L/100 km; 50 mpg-US)[54] | ||
Ford Focus 1.6 TDCi Style — Overall Winner 2008[55] | 2008 | Clean diesel | UK combined 52 mpg-imp (5.4 L/100 km; 43 mpg-US)[56] | ||
American Council for an Energy-Efficient Economy Greenest Vehicles of the Year | |||||
Greenest Vehicles of 2010 (Top 5)[57] | |||||
Honda Civic GX | 2010 | Natural gas | 28 | 24 | 36 |
Toyota Prius | 2010 | Hybrid electric | 50 | 51 | 48 |
Honda Civic Hybrid | 2010 | Hybrid electric | 42 | 40 | 45 |
Smart fortwo (Convertible/coupe) | 2010 | Gasoline | 36 | 33 | 41 |
Honda Insight | 2010 | Hybrid electric | 41 | 40 | 43 |
Greenest Vehicles of 2011[58][59] | |||||
Honda Civic GX | 2011 | Natural gas | 28 | 24 | 36 |
Nissan Leaf | 2011 | Electric car | 99 mpg-e | 3.15 mile/Kwh | 2.72 mile/Kwh |
Smart fortwo (Cabriolet/Coupe) | 2011 | Gasoline | 36 | 33 | 41 |
Toyota Prius | 2011 | Hybrid electric | 50 | 51 | 48 |
Honda Civic Hybrid | 2011 | Hybrid electric | 41 | 40 | 43 |
Honda Insight | 2011 | Hybrid electric | 41 | 40 | 43 |
Ford Fiesta SFE manual | 2011 | Gasoline | 33 | 29 | 40 |
Chevrolet Cruze ECO manual 1.4L | 2011 | Gasoline | n.a. | 28 | 42 |
Hyundai Elantra manual 1.8L | 2011 | Gasoline | 33 | 29 | 40 |
MINI Cooper (manual) | 2011 | Gasoline | 32 | 29 | 37 |
Toyota Yaris (manual) | 2011 | Gasoline | 32 | 29 | 36 |
Mazda 2 (manual) | 2011 | Gasoline | n.a. | 29 | 35 |
Chevrolet Volt | 2011 | Plug-in hybrid | 37 | 35 | 40 |
n.a. | 2.81 mile/Kwh | 2.76 mile/Kwh | |||
Mother Earth News Best Green Cars of 2010[60] | |||||
Ford Fusion Hybrid | 2010 | Hybrid electric | 39 | 41 | 36 |
Honda Civic Hybrid | 2010 | Hybrid electric | 42 | 40 | 45 |
Honda Insight | 2010 | Hybrid electric | 41 | 40 | 43 |
Toyota Prius | 2010 | Hybrid electric | 50 | 51 | 48 |
VW Golf TDI | 2010 | Clean diesel | 34 | 30 | 42 |
VW Jetta TDI | 2010 | Clean diesel | 41 | 40 | 43 |
Kelley Blue Book Top 10 Green Cars | |||||
Green Cars of 2010 (Top 5)[61][62] | |||||
Toyota Prius | 2010 | Hybrid electric | 50 | 51 | 48 |
Honda Insight | 2010 | Hybrid electric | 41 | 40 | 43 |
Ford Fusion Hybrid | 2010 | Hybrid electric | 39 | 41 | 36 |
VW Golf TDI | 2010 | Clean diesel | 34 | 30 | 42 |
MINI Cooper | 2010 | Gasoline | 32 | 28 | 37 |
Top 10 Green Cars of 2011[63][64] | |||||
Nissan Leaf | 2011 | Electric car | Gasoline equivalent fuel economy |
All-electric range | |
99 mpg-e | 73 mi | ||||
Chevrolet Volt | 2011 | Plug-in hybrid | Gasoline equivalent fuel economy |
All-electric range | |
93 mpg-e | 35 mi | ||||
Toyota Prius | 2011 | Hybrid electric | 50 | 51 | 48 |
Lexus CT 200h | 2011 | Hybrid electric | 42 | 43 | 40 |
Honda Insight | 2011 | Hybrid electric | 41 | 40 | 43 |
Ford Fusion Hybrid | 2011 | Hybrid electric | 39 | 41 | 36 |
VW Golf TDI | 2011 | Clean diesel | 34 | 30 | 42 |
Hyundai Elantra | 2011 | Gasoline | 33 | 29 | 40 |
Fiat 500 | 2012 | Gasoline | 33 | 30 | 38 |
Ford Focus | 2012 | Gasoline | 31 | 28 | 38 |
Dedicated electric and green vehicle motor shows:
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