On March 27, the California Air Resources Board (CARB) modified their regulations, requiring automobile manufacturers to produce 58,000 plug-in hybrids during 2012 through 2014.[ "Preliminary Summary of Air Resources Board Action (3/27/08) – Zero Emission Vehicle (ZEV) Program" arb.ca.gov] This requirement is an asked-for alternative to an earlier mandate to produce 25,000 pure zero-emissions vehicles, reducing that requirement to 5,000.[California Air Resources Board (March 27, 2008) "ARB passes new ZEV amendment – Measure could produce 65,000 cleaner vehicles by 2012" (government agency release)] On June 26, Volkswagen announced that they would be introducing production plug-ins based on the Volkswagen Golf compact car. Volkswagen uses the term 'TwinDrive' to denote a PHEV.[Thompson (June 26, 2008) "VW starts testing electric cars, sees launching them by 2010" (Forbes) accessed December 2009] In September, Mazda was reported to be planning PHEVs.
On October 3, the U.S. enacted the Energy Improvement and Extension Act of 2008. The legislation provided tax credits for the purchase of plug-in electric vehicles of battery capacity over 4 kilowatt-hours.[Schoenberger, R. (October 2, 2008) "Bailout bill includes tax breaks for buyers of plug-in hybrid vehicles," Cleveland Plain Dealer][Vijayenthiran, V. (October 3, 2008) "Bush signs $7,500 plug-in hybrid tax credit bill into law," MotorAuthority.com] The federal tax credits were extended and modified by the American Clean Energy and Security Act of 2009, but now the battery capacity must be over 5 kWh and the credit phases out after the automaker has sold at least 200,000 vehicles in the U.S.
[
]
Toyota tested 600 pre-production Prius Plug-ins in Europe and North America in 2009 and 2010.
In October 2010 Lotus Engineering unveiled the Lotus CityCar, a plug-in series hybrid concept car designed for flex-fuel operation on ethanol fuel, or methanol fuel as well as regular gasoline.
GM launched the Chevrolet Volt in the U.S. on November 30, 2010, and retail deliveries began in December 2010.
The first deliveries of the Fisker Karma took place in July 2011,
The Honda Accord Plug-in Hybrid was released in selected U.S. markets in January 2013,
Deliveries to retail customers of the limited edition McLaren P1 supercar began in the UK in October 2013,
In 2013, Volkswagen started limited production on the Volkswagen XL1, a two-seater diesel-powered plug-in hybrid vehicle designed to be able to travel on diesel, while still being both roadworthy and practical. The model is unique in that it is one of the only mass produced plug-in diesel hybrid vehicles and one of the only mass produced diesel hybrid vehicles in general.
In December 2014 BMW announced the group is planning to offer plug-in hybrid versions of all its core-brand models using eDrive technology developed for its BMW i brand plug-in vehicles (BMW i3 and BMW i8). The goal of the company is to use plug-in technology to continue offering high performance vehicles while reducing emissions below 100g/km.
In March 2015 Audi said they planned on making a plug-in hybrid version of every model series, and that they expect plug-in hybrids, together with natural gas vehicles and battery-electric drive systems, to have a key contribution in achieving the company's targets.
By the end of 2015, over 517,000 highway legal plug-in hybrid electric cars have been sold worldwide since December 2008 out of total global sales of more than 1.25 million light-duty plug-in electric cars.[ About 520,000 highway legal light-duty plug-in electric vehicles were sold worldwide in 2015, with cumulative global sales reaching 1,235,000. Plug-in hybrids represent about 40% of global plug-in electric vehicle sales .]
Hyundai Motor Company made the official debut of its three model Hyundai Ioniq line-up at the 2016 Geneva Motor Show.
The second generation Prius plug-in hybrid, called Prius Prime in the U.S. and Prius PHV in Japan,
Global sales of the Mitsubishi Outlander PHEV passed the 100,000 unit milestone in March 2016.[ , the world's top selling plug-in electric cars are the Nissan Leaf (over 218,000), Tesla Model S (about 120,000), Chevrolet Volt and Ampera variants (over 110,000), Mitsubishi Outlander PHEV (over 100,000), and Toyota Prius Plug-in Hybrid (75,000). All figures cumulative global sales since market launch.][ , a total of 65,529 units have been sold in Europe (21,052 in the UK and 44,477 in the rest of Europe), 33,730 in Japan, 2,015 in Australia and 259 in the rest of the world, for a total of 101,533 units sold worldwide.]
In January 2016, Chrysler debuted its plug-in hybrid minivan, the Chrysler Pacifica Hybrid.
In December 2017, Honda began retail deliveries of the Honda Clarity in the United States and Canada.
In 2019, General Motors ended production of all plug-in hybrid models, including the Chevrolet Volt and the Cadillac CT6 PHEV, as it focuses on battery electric vehicles.
In March 2019, Chinese start-up manufacturer Li Auto introduced its first model, the Li One, a plug-in hybrid vehicle which became the first range extender electric vehicle from China. It is powered 1.2-liter turbocharged petrol engine, used exclusively as a range extender to recharge the battery, and an electric motor.
In May 2019, at the high-performance end, Ferrari presented the Ferrari SF90 Stradale, a plug-in hybrid supercar. A 7.9 kWh lithium-ion battery for provides of electric range and powers three electric motors, adding a combined output of
In December 2019, Toyota introduced its first plug-in hybrid SUV, the Toyota RAV4 Prime/PHEV. The model has a claimed acceleration of in 6.2 seconds, which, at the time of its introduction, made it the quickest Toyota model by acceleration after the Toyota GR Supra sports car.
In 2020 and 2021, Hyundai Motor Group started adding new plug-in hybrid vehicles in its line-up, such as the Hyundai Tucson Plug-In Hybrid, Hyundai Santa Fe Plug-In Hybrid, Kia Ceed PHEV, Kia Sportage PHEV, and Kia Sorento PHEV. These models are offered mainly for Europe, and in addition North America.
In June 2020, BYD Auto introduced a petrol engine dedicated solely for plug-in hybrid application called the Xiaoyun. The 1.5-liter engine is designed specifically for its newly introduced DM-i plug-in hybrid technology. The engine uses the Atkinson cycle and has a thermal efficiency of up to 43%, which was among the highest for mass-produced petrol engines globally. The DM-i system itself adopts a complex "electric-based" series-parallel architecture. BYD also emphasized that vehicles equipped with this technology will be priced competitively with petrol-powered vehicles.
In North America, Stellantis began sales of the Jeep Wrangler 4xe in 2021. It is the plug-in hybrid version of the JL Wrangler that offers around pure electric range. It became the best-selling plug-in hybrid in the United States in 2022, outselling the Toyota RAV4 Prime.
In October 2021, Mitsubishi Motors updated the Mitsubishi Outlander PHEV with a new generation.
Honda discontinued its only plug-in hybrid model in markets outside China, the Honda Clarity Plug-In Hybrid in 2021.
The Mazda CX-60 PHEV, the first plug-in hybrid vehicle from Mazda, went on sale in early 2022 initially for the European market.
In April 2024, BYD Auto launched the DM-i 5.0, its fifth-generation plug-in hybrid technology on the BYD Qin L DM-i and BYD Seal 06 DM-i.
In October 2024, Geely released the Leishen EM-i plug-in hybrid system, also known as the NordThor 2.0, which directly competes with BYD's technology.
Nissan released its first ever plug-in hybrid vehicle in April 2025, the Nissan Frontier Pro pickup truck.
On February 23, 2026, Chery revealed an unnamed pickup truck codenamed KP31, which will become the first ever diesel plug-in hybrid pickup truck. It is set to enter production and launch in Q4 2026, with Australia being its first market. A near-production version was unveiled at a press event on the same day in Sydney, Australia.
Technology
Powertrains
operates primarily as a series hybrid.]]PHEVs are based on the same three basic powertrain architectures of conventional hybrids; a series hybrid is propelled by electric motors only, a parallel hybrid is propelled both by its internal combustion engine and by electric motors operating concurrently, and a series-parallel hybrid operates in either mode. While a plain hybrid vehicle charges its battery from its engine only, a plug-in hybrid can obtain a significant amount of the energy required to recharge its battery from external sources.
Dual plug-in hybrids
These contain two different energy recovery systems.
The Mercedes-AMG ONE is a plug-in dual hybrid.
The Mercedes-Benz C-Class (W206) and the Mercedes C254/X254 also have an electrically assisted turbocharger/MGU-H.
Fuel cell plug-in hybrid
The is a plug-in hybrid electric, fuel cell vehicle. It is equipped with a front-mounted electric motor, two high-pressure with a total capacity of , a 17.7 kWh battery with plug-in charging capability with no internal combustion engine.
Charging systems
The battery charger can be on-board or external to the vehicle. The process for an on-board charger is best explained as AC power being converted into DC power, resulting in the battery being charged.
Using the electric motor's inverter allows the motor windings to act as the transformer coils, and the existing high-power inverter as the AC-to-DC charger. As these components are already required on the car, and are designed to handle any practical power capability, they can be used to create a very powerful form of on-board charger with no significant additional weight or size. AC Propulsion uses this charging method, referred to as "reductive charging".
Modes of operation
A plug-in hybrid operates in charge-depleting and charge-sustaining modes. Combinations of these two modes are termed blended mode or mixed-mode. These vehicles can be designed to drive for an extended range in all-electric mode, either at low speeds only or at all speeds. These modes manage the vehicle's battery discharge strategy, and their use has a direct effect on the size and type of battery required:
Charge-depleting mode allows a fully charged PHEV to operate exclusively (or depending on the vehicle, almost exclusively, except during hard acceleration) on electric power until its battery state of charge is depleted to a predetermined level, at which time the vehicle's internal combustion engine or fuel cell will be . This period is the vehicle's all-electric range. This is the only mode that a battery electric vehicle can operate in, hence their limited range.
Mixed mode describes a trip using a combination of multiple modes. For example, a car may begin a trip in low-speed charge-depleting mode, then enter onto a freeway and operate in blended mode. The driver might exit the freeway and drive without the internal combustion engine until all-electric range is exhausted. The vehicle can revert to a charge sustaining-mode until the final destination is reached. This contrasts with a charge-depleting trip that would be driven within the limits of a PHEV's all-electric range.
Most PHEV's also have two additional charge sustaining modes:
Battery hold; the electric motor is locked out and the vehicle operates exclusively on combustion power, so that whatever charge is left in the battery remains for when mixed mode or full electric operation are re-engaged, whilst regenerative braking will still be available to boost the battery charge. On some PHEVs, vehicle services that use the traction battery (such as heating and air conditioning) are placed in a low power consumption mode to further conserve the remaining battery charge. The lock-out of the electric motor is automatically overridden (charge permitting) should full acceleration be required.
Self charge; the electric motor's armature is engaged to the transmission, but is connected to the battery so that it runs as a generator and therefore recharges the battery whilst the car is in motion, although this comes at the expense of higher fuel consumption, as the combustion engine has to both power the vehicle itself and charge the battery. This is useful for 'charging on the move' when there are limited places to plug the vehicle in.
Electric power storage
The optimum battery size varies depending on whether the aim is to reduce fuel consumption, running costs, or emissions, but a 2009 study
PHEVs typically require deeper battery charging and discharging cycles than conventional hybrids. Because the number of full cycles influences battery life, this may be less than in traditional HEVs, which do not deplete their batteries as fully. Nonetheless, some authors argue that PHEVs will soon become standard in the automobile industry.
The cathodes of some early 2007 lithium-ion batteries are made from lithium–cobalt metal oxide. This material is expensive, and cells made with it can release oxygen if overcharged. If the cobalt is replaced with iron phosphates, the cells will not burn or release oxygen under any charge. At early 2007 gasoline and electricity prices, the break-even point is reached after six to ten years of operation. The payback period may be longer for plug-in hybrids, because of their larger, more expensive batteries.
Nickel–metal hydride and lithium-ion batteries can be recycled; Toyota, for example, has a recycling program in place under which dealers are paid a US$200 credit for each battery returned.[Woody, Todd. "PG&E's Battery Power Plans Could Jump Start Electric Car Market". (Blog). Green Wombat, 2007-06-12. Retrieved 2007-08-19.] More recently, General Motors (GM) has said it has been "approached by utilities interested in using recycled Volt batteries as a power storage system, a secondary market that could bring down the cost of the Volt and other plug-in vehicles for consumers".[Jansen, Matt. "Toyota laughs while Chevy Volt battery power is ripped in half". (Blog). tech.blorge, 2008-6-16. Retrieved 2008-6-17.]
(or "supercapacitors") are used in some plug-in hybrids, such as AFS Trinity's concept prototype, to store rapidly available energy with their high power density, in order to keep batteries within safe resistive heating limits and extend battery life.[ "UltraBattery FAQs" , 2010-05-06]
Conversions of production vehicles
There are several companies that are converting fossil fuel non-hybrid vehicles to plug-in hybrids:
Aftermarket conversion of an existing production hybrid to a plug-in hybrid
Many early plug-in hybrid electric vehicle conversions have been based on the Toyota Prius.[California Cars Initiative (2007) "Where Plug-In Hybrid Conversions (mostly Priuses) Are" . Retrieved July 8, 2007.] Some of the systems have involved replacement of the vehicle's original NiMH battery pack and its electronic control unit. Others add an additional battery back onto the original battery pack.[A123 Systems, Inc. (May 3, 2007) A123Systems Battery Co Acquires Hymotion Conversion Co Business Wire press release]
Target market
In recent years, demand for all- electric vehicles, especially in the United States market, has been driven by government incentives through subsidies, lobbyists, and taxes.
Plug-in hybrids provide the extended range and potential for refueling of conventional hybrids while enabling drivers to use battery electric power for at least a significant part of their typical daily driving. The average trip to or from work in the United States in 2009 was ,
A key design parameter of the Chevrolet Volt was a target of for the all-electric range, selected to keep the battery size small and lower costs, and mainly because research showed that 78% of daily commuting in the U.S. travel or less. This target range would allow most travel to be accomplished electrically driven and the assumption was made that charging will take place at home overnight. This requirement translated using a lithium-ion battery pack with an energy storage capacity of considering that the battery would be used until the state of charge (SOC) of the battery reached 30%.
In October 2014 General Motors reported, based on data collected through its OnStar telematics system since Volt deliveries began, and with over 1 billion miles (1.6 billion km) traveled, that Volt owners drive about 62.5% of their trips in all-electric mode.
The 2015 edition of the EPA's annual report " Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends" estimates the following utility factors for 2015 model year plug-in hybrids to represent the percentage of miles that will be driven using electricity by an average driver, whether in electric only or blended modes: 83% for the BMW i3 REx, 66% for the Chevrolet Volt, 45% for the Ford Energi models, 43% for the McLaren P1, 37% for the BMW i8, and 29% for the Toyota Prius PHV.[ See Table 7.2 – MY 2015 Alternative Fuel Vehicle Powertrain and Range.] A 2014 analysis conducted by the Idaho National Laboratory using a sample of 21,600 all-electric cars and plug-in hybrids, found that Volt owners traveled on average 9,112 miles in all-electric mode (e-miles) per year, while Leaf owners traveled 9,697 e-miles per year, despite the Volt's shorter all-electric range, about half of the Leaf's.
Comparison to non-plug-in hybrids
Fuel efficiency and petroleum displacement
Plug-in hybrids have the potential to be even more efficient than conventional hybrids because a more limited use of the PHEV's internal combustion engine may allow the engine to be used at closer to its maximum efficiency. While a Toyota Prius is likely to convert fuel to motive energy on average at about 30% efficiency (well below the engine's 38% peak efficiency), the engine of a PHEV with of electric range would be likely to operate far more often near its peak efficiency because the batteries can serve the modest power needs at times when the combustion engine would be forced to run well below its peak efficiency.
Each kilowatt hour of battery capacity in use will displace up to of per year (gasoline or Diesel fuel).[International Humanities Center (September 24, 2008) "Senate OKs Plug-In Credits, Toyota Frets; Free Press Lyrical about Plug-Ins" California Cars Initiative] Also, electricity is multi-sourced and, as a result, it gives the greatest degree of energy resilience.[Grove, Andy (July/August 2008) "Our Electric Future" The American (American.com)]
The actual fuel economy for PHEVs depends on their powertrain's operating modes, the all-electric range, and the amount of driving between charges. If no gasoline is used the miles per gallon gasoline equivalent (MPG-e) depends only on the efficiency of the electric system. The first mass production PHEV available in the U.S. market, the 2011 Chevrolet Volt, with an EPA rated all-electric range of and an additional gasoline-only extended range of , has an EPA combined city/highway fuel economy of 93 MPG-e in all-electric mode, and in gasoline-only mode, for an overall combined gas-electric fuel economy rating of equivalent (MPG-e).[ According to this table the fuel economy goes up to equivalent (MPG-e) with driven between full charges.][
]
For the more comprehensive fuel economy and environment label that will be mandatory in the U.S. beginning in model year 2013, the National Highway Traffic Safety Administration (NHTSA) and Environmental Protection Agency (EPA) issued two separate fuel economy labels for plug-in hybrids because of their design complexity, as PHEVS can operate in two or three operating modes: all-electric, blended, and gasoline-only.[ EPA-420-F-11-017] One label is for series hybrid or extended range electric vehicle (like the Chevy Volt), with all-electric and gasoline-only modes; and a second label for blended mode or series-parallel hybrid, that includes a combination of both gasoline and plug-in electric operation; and gasoline only, like a conventional hybrid vehicle.[
]
The Society of Automotive Engineers (SAE) developed their recommended practice in 1999 for testing and reporting the fuel economy of hybrid vehicles and included language to address PHEVs. An SAE committee is currently working to review procedures for testing and reporting the fuel economy of PHEVs.[US Department of Energy (September 18, 2007) "Plug-In Hybrid Electric Vehicle Conversions" Alternative Fuels and Advanced Vehicles Data Center Retrieved November 8, 2007.] The Toronto Atmospheric Fund tested ten retrofitted plug-in hybrid vehicles that achieved an average of 5.8 litres per 100 kilometre or 40.6 miles per gallon over six months in 2008, which was considered below the technology's potential.[Hamilton, Tyler. $3.83 to power hybrid plug-in for 6 days . June 9, 2008]
In real world testing using normal drivers, some Prius PHEV conversions may not achieve much better fuel economy than HEVs. For example, a plug-in Prius fleet, each with a all-electric range, averaged only in a test in Seattle,[Westneat, D. (February 22, 2009) Reality check on plug-in cars ] and similar results with the same kind of conversion battery models at Google's RechargeIT initiative. Moreover, the additional battery pack costs –.
Operating costs
A study published in 2014 by researchers from Lamar University, Iowa State University and Oak Ridge National Laboratory compared the operating costs of PHEVs of various electric ranges (10, 20, 30, and 40 miles) with conventional gasoline vehicles and non-plugin hybrid-electric vehicles (HEVs) for different payback periods, considering different charging infrastructure deployment levels and gasoline prices. The study concluded that:[ For more details see: Xing Wu, Jing Dong, Zhenhong Lin (2014) Cost analysis of plug-in hybrid electric vehicles using GPS-based longitudinal travel data, Energy Policy, Volume 68, Pages 206–217, doi: 10.1016/j.enpol.2013.12.054]
-
PHEVs save around 60% or 40% in energy costs, compared with conventional gasoline vehicles and HEVs, respectively. For drivers with significant daily vehicle miles traveled (DVMT), however, hybrid vehicles may be even a better choice than plug-in hybrids with a range of , particularly when there is a lack of public charging infrastructure.
-
The incremental battery cost of large-battery plug-in hybrids is difficult to justify based on the incremental savings of PHEVs' operating costs unless a subsidy is offered for large-battery PHEVs.
-
When the price of gasoline increases from per gallon to per gallon, the number of drivers who benefit from a larger battery increases significantly. If the gas price is , a plug-in hybrid with a range of is the least costly option even if the battery cost is $200/kWh.
-
Although quick chargers can reduce charging time, they contribute little to energy cost savings for PHEVs, as opposed to Level-2 chargers.
Cost of batteries
Disadvantages of PHEVs include the additional cost, weight and size of a larger battery pack. According to a 2010 study by the National Research Council, the cost of a lithium-ion battery pack is about /kW·h of usable energy, and considering that a PHEV with of electric range requires about 2.0 kW·h and a PHEV with of electric range about 8 kW·h, the estimated manufacturer cost of the battery pack for a PHEV with of electric range is around and it goes up to for a PHEV with of electric range.
+Cost comparison between a PHEV-10 and a PHEV-40
(prices for 2010) |
Annual
gasoline
savings
compared
to a HEV(2) |
| |
| |
Notes: (1) Considers the HEV technology used in the Toyota Prius with a larger battery pack. The Prius Plug-in estimated all-electric range is
(2) Assuming per year. |
According to the 2010 NRC study, although a mile driven on electricity is cheaper than one driven on gasoline, lifetime fuel savings are not enough to offset plug-ins' high upfront costs, and it will take decades before the break-even point is achieved.[ Furthermore, hundreds of billions of dollars in government subsidies and incentives are likely to be required to achieve rapid plug-in market penetration in the U.S.][
]
A 2013 study by the American Council for an Energy-Efficient Economy reported that battery costs came down from per kilowatt hour in 2007 to per kilowatt hour in 2012. The U.S. Department of Energy has set cost targets for its sponsored battery research of per kilowatt hour in 2015 and per kilowatt hour by 2022. Cost reductions through advances in battery technology and higher production volumes will allow plug-in electric vehicles to be more competitive with conventional internal combustion engine vehicles.[ ACEEE Report Number T133.]
A study published in 2011 by the Belfer Center, Harvard University, found that the gasoline costs savings of PHEVs over the vehicles' lifetimes do not offset their higher purchase prices. This finding was estimated comparing their lifetime net present value at 2010 purchase and operating costs for the U.S. market, and assuming no government subidies.[
]Discussion Paper #2011-08.
According to the study estimates, a PHEV with of electric range is more expensive than a conventional internal combustion engine, while a battery electric vehicle (BEV) is more expensive. The study also examined how this balance will change over the next 10 to 20 years, assuming that battery costs will decrease while gasoline prices increase. Under the future scenarios considered, the study found that BEVs will be significantly less expensive than conventional cars ( to cheaper), while PHEVs, will be more expensive than BEVs in almost all comparison scenarios, and only less expensive than conventional cars in a scenario with very low battery costs and high gasoline prices. BEVs are simpler to build and do not use liquid fuel, while PHEVs have more complicated powertrains and still have gasoline-powered engines.
Emissions shifted to electric plants
Increased pollution is expected to occur in some areas with the adoption of PHEVs, but most areas will experience a decrease.[Knipping, E. and Duvall, M. (June 2007) "Environmental Assessment of Plug-In Hybrid Electric Vehicles Volume 2: United States Air Quality Analysis Based on AEO-2006 Assumptions for 2030" Electric Power Research Institute and Natural Resources Defense Council. Retrieved July 21, 2007.] A study by the ACEEE predicts that widespread PHEV use in heavily coal-dependent areas would result in an increase in local net sulfur dioxide and mercury emissions, given emissions levels from most coal plants currently supplying power to the grid.[Clayton, M. (September 25, 2006) "A reality check on plug-in hybrids" The Christian Science Monitor] Although clean coal technologies could create power plants that supply grid power from coal without emitting significant amounts of such pollutants, the higher cost of the application of these technologies may increase the price of coal-generated electricity. The net effect on pollution is dependent on the fuel source of the electrical grid (fossil or renewable, for example) and the pollution profile of the power plants themselves. Identifying, regulating and upgrading single point pollution source such as a power plant—or replacing a plant altogether—may also be more practical. From a human health perspective, shifting pollution away from large urban areas may be considered a significant advantage.
According to a 2009 study by The National Academy of Science, "Electric vehicles and grid-dependent (plug-in) hybrid vehicles showed somewhat higher nonclimate damages than many other technologies."[ Technology Options 2003. (2003). US Climate Change Technology Program.] and 6.5% in 2007.
Tiered rate structure for electric bills
The additional electrical consumption to recharge the plug-in vehicles could push many households in areas that do not have off-peak tariffs into the higher priced tier and negate financial benefits.
Greenhouse gas emissions
The effect of PHEVs on greenhouse emissions is complex. Plug-in hybrid vehicles operating on all-electric mode do not emit harmful tailpipe pollutants from the onboard source of power. The clean air benefit is usually local because depending on the source of the electricity used to recharge the batteries, air pollutant emissions are shifted to the location of the generation plants.[ pages=2–5] On the other hand, when PEVs are recharged from coal-fired plants, they usually produce slightly more greenhouse gas emissions than internal combustion engine vehicles.[ In the case of plug-in hybrid electric vehicle when operating in hybrid mode with assistance of the internal combustion engine, tailpipe and greenhouse emissions are lower in comparison to conventional cars because of their higher fuel economy.][
]
Life cycle energy and emissions assessments
Argonne
In 2009, researchers at Argonne National Laboratory adapted their GREET model to conduct a full well-to-wheels (WTW) analysis of energy use and greenhouse gas (GHG) emissions of plug-in hybrid electric vehicles for several scenarios, considering different on-board fuels and different sources of electricity generation for recharging the vehicle batteries. Three US regions were selected for the analysis, California, New York, and Illinois, as these regions include major metropolitan areas with significant variations in their energy generation mixes. The full cycle analysis results were also reported for the US generation mix and renewable electricity to examine cases of average and clean mixes, respectively[ Report ANL/ESD/09-2] This 2009 study showed a wide spread of petroleum use and GHG emissions among the different fuel production technologies and grid generation mixes. The following table summarizes the main results:[
]
|
|
| |
| |
Source: Center for Transportation Research, Argonne National Laboratory (2009). See Table 1.[ Notes: (1) Simulations for year 2020]
with PHEV model year 2015. (2) No direct or indirect land use changes included in the WTW analysis for bio-mass fuel feedstocks.[ Originally published online in Science Express on 2008-02-07. See Letters to Science by Wang and Haq. There are critics to these findings for assuming a worst-case scenario.][ Originally published online in Science Express on 2008-02-07. There are rebuttals to these findings for assuming a worst-case scenario] |
The Argonne study found that PHEVs offered reductions in petroleum energy use as compared with regular hybrid electric vehicles. More petroleum energy savings and also more GHG emissions reductions were realized as the all-electric range increased, except when electricity used to recharge was dominated by coal or oil-fired power generation. As expected, electricity from renewable sources realized the largest reductions in petroleum energy use and GHG emissions for all PHEVs as the all-electric range increased. The study also concluded that plug-in vehicles that employ biomass-based fuels (biomass-E85 and -hydrogen) may not realize GHG emissions benefits over regular hybrids if power generation is dominated by fossil sources.[
]
Oak Ridge
A 2008 study by researchers at Oak Ridge National Laboratory analyzed oil use and greenhouse gas (GHG) emissions of plug-in hybrids relative to hybrid electric vehicles under several scenarios for years 2020 and 2030.[ Report ORNL/TM-2007/150] The study considered the mix of power sources for 13 U.S. regions that would be used during recharging of vehicles, generally a combination of coal, natural gas and nuclear energy, and to a lesser extent renewable energy.
Environmental Protection Agency
In October 2014, the U.S. Environmental Protection Agency published the 2014 edition of its annual report Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends. For the first time, the report presents an analysis of the impact of alternative fuel vehicles, with emphasis in plug-in electric vehicles because as their market share is approaching 1%, PEVs began to have a measurable impact on the U.S. overall new vehicle fuel economy and emissions.[ See table 7.3 - Overall fuel economy (mpg-e), pp. 100.]
EPA's report included the analysis of 12 all-electric passengers cars and 10 plug-in hybrids available in the market as model year 2014. For purposes of an accurate estimation of emissions, the analysis took into consideration the differences in operation between those PHEVs like the Chevrolet Volt that can operate in all-electric mode without using gasoline, and those that operate in a blended mode like the Toyota Prius PHV, which uses both energy stored in the battery and energy from the gasoline tank to propel the vehicle, but that can deliver substantial all-electric driving in blended mode. In addition, since the all-electric range of plug-in hybrids depends on the size of the battery pack, the analysis introduced a utility factor as a projection, on average, of the percentage of miles that will be driven using electricity (in electric only and blended modes) by an average driver. The following table shows the overall EV/hybrid fuel economy expressed in terms of miles per gallon gasoline equivalent (mpg-e) and the utility factor for the ten MY2014 plug-in hybrids available in the U.S. market. The study used the utility factor (since in pure EV mode there are no tailpipe emissions) and the EPA best estimate of the tailpipe emissions produced by these vehicles in real world city and highway operation based on the EPA 5-cycle label methodology, using a weighted 55% city/45% highway driving. The results are shown in the following table.[
]
In addition, the EPA accounted for the upstream emissions associated with the production and distribution of electricity required to charge the PHEVs. Since electricity production in the United States varies significantly from region to region, the EPA considered three scenarios/ranges with the low end of the range 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 Rockies. The EPA estimates that the electricity GHG emission factors for various regions of the country vary from 346 g /kW-hr in California to 986 g /kW-hr in the Rockies, with a national average of 648 g /kW-hr.[ The following table shows the tailpipe emissions and the combined tailpipe and upstream emissions for each of the 10 MY 2014 PHEVs available in the U.S. market.
]
|
|
|
| 288 |
| 326 |
| 377 |
| 326 |
| 326 |
| 257 |
| 249 |
| 404 |
| 457 |
| 687 |
|
Notes: (1) Based on 45% highway and 55% city driving. (2) The utility factor represents, on average, the percentage of miles that will be driven using electricity (in electric only and blended modes) by an average driver. (3) The EPA classifies the i3 REx as a series plug-in hybrid[ pp. 33–36] |
National Bureau of Economic Research
Most emission analysis use average emissions rates across regions instead of marginal generation at different times of the day. The former approach does not take into account the generation mix within interconnected electricity markets and shifting load profiles throughout the day.[ Published on line 2014-03-24. See pp. 251] An analysis by three economist affiliated with the National Bureau of Economic Research (NBER), published in November 2014, developed a methodology to estimate marginal emissions of electricity demand that vary by location and time of day across the United States. The study used emissions and consumption data for 2007 through 2009, and used the specifications for the Chevrolet Volt (all-electric range of ). The analysis found that marginal emission rates are more than three times as large in the Upper Midwest compared to the Western U.S., and within regions, rates for some hours of the day are more than twice those for others.[ Applying the results of the marginal analysis to plug-in electric vehicles, the NBER researchers 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. 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. The results show a fundamental 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 units, which have higher emission rates, are most commonly used to meet base-level and off-peak electricity demand; while natural gas units, which have relatively low emissions rates, are often brought online to meet peak demand. This pattern of fuel shifting explains why emission rates tend to be higher at night and lower during periods of peak demand in the morning and evening.][
]
Production and sales
Production models
Since 2008, plug-in hybrids have been commercially available from both specialty manufacturers and from mainstream producers of internal combustion engine vehicles. The F3DM, released in China in December 2008, was the first production plug-in hybrid sold in the world.[ The Chevrolet Volt, launched in the U.S. in December 2010, was the first mass-production plug-in hybrid by a major carmaker.][
]
Sales and main markets
There were 1.2 million plug-in hybrid cars on the world roads at the end of 2017.[ The stock of plug-in hybrids increased to 1.8 million in 2018, out of a global stock of about 5.1 million plug-in electric passenger cars.][ , the United States ranked as the world's largest plug-in hybrid car market with a stock of 360,510 units, followed by China with 276,580 vehicles, Japan with 100,860 units, the Netherlands with 98,220, and the UK with 88,660.][ See pp. 9–10, 19–23, 29–28, and Statistical annex, pp. 107–113.]
Global sales of plug-in hybrids grew from over 300 units in 2010 to almost 9,000 in 2011, jumped to over 60,000 in 2012, and reached almost 222,000 in 2015.[ See pp. 4–5, and 24–25 and Statistical annex, pp. 34–37.] , the United States was the world's largest plug-in hybrid car market with a stock of 193,770 units.[ About 279,000 light-duty plug-in hybrids were sold in 2016,][ Global light-duty plug-in vehicles sales totaled almost 775,000 units in 2016, of which, 36% were plug-in hybrids.] raising the global stock to almost 800,000 highway legal plug-in hybrid electric cars at the end of 2016.[ An estimated 2,032,000 highway-legal plug-in passenger cars and vans have been sold worldwide at the end of 2016. The top selling markets are China (645,708 new energy cars, including imports), Europe (638,000 plug-in cars and vans), and the United States (570,187 plug-in cars). The top European country markets are Norway (135,276), the Netherlands (113,636), France (108,065), and the UK (91,000). Total Chinese sales of domestically produced new energy vehicles, including buses and truck, totaled 951,447 vehicles. China was the top selling plug-in car market in 2016, and also has the world's largest stock of plug-in electric cars.] A total of 398,210 plug-in hybrid cars were sold in 2017, with China as the top selling country with 111,000 units, and the global stock of plug-in hybrids passed the one million unit milestone by the end of 2017.[
]
Global sales of plug-in electric vehicles have been shifting for several years towards fully electric battery cars. The global ratio between all-electrics (BEVs) and plug-in hybrids (PHEVs) went from 56:44 in 2012, to 60:40 in 2015, to 66:34 in 2017, and rose to 69:31 in 2018.[ In 2023, the ratio was 70:30, an increase for plug-in hybrids from the previous 73:27 in 2022.]
China's contribution towards global plug-in hybrids share ranged from 30% to 50% in 2017–2018, and fell to 25% in 2020. In 2021, China's share of global plug-in hybrids was 32%, rising to 55% in 2022, and 69% in 2023. From January to August 2024, the share rose to 77%, of which the third quarter reached 82%.
+Countries and regions by contribution of global plug-in hybrid sales | Region
!2019
!2020
!2021
!2022
!2023
!2024 (Q1–Q3) |
| | 41.9% | 24.6% | 32.3% | 55.5% | 68.9% | 76.6% |
| Europe | | 9.2% | 25.6% | 18.0% | 13.2% | 4.4% | 3.2% |
| | 5.9% | 6.9% | 7.1% | 3.8% | 3.5% | 2.8% |
| | 3.9% | 9.0% | 8.0% | 4.7% | 4.1% | 2.4% |
| | 5.5% | 7.1% | 4.3% | 2.5% | 1.5% | 1.1% |
| | 1.2% | 2.6% | 5.2% | 3.4% | 1.7% | 1.0% |
| | 3.9% | 3.3% | 2.1% | 0.6% | 0.3% | 0.1% |
| Other Europe | 7.3% | 10.7% | 11.5% | 6.9% | 6.4% | 4.8% |
| Europe total | 36.9% | 65.5% | 56.1% | 35.1% | 21.9% | 15.4% |
| North America | | 16.9% | 7.5% | 9.2% | 6.9% | 7.0% | 5.8% |
| Other North America | 0.6% | 0.1% | 0.0% | 0.0% | 0.0% | 0.0% |
| North America total | 17.6% | 7.6% | 9.2% | 6.9% | 7.1% | 5.8% |
| Asia (except China) | | 3.0% | 1.3% | 1.3% | 1.4% | 1.3% | 1.3% |
| | 0.6% | 1.0% | 1.0% | 0.4% | 0.2% | 0.1% |
| Other Asia | 0.0% | 0.1% | 0.1% | 0.6% | 0.4% | 0.2% |
| Asia total | 3.6% | 2.4% | 2.3% | 2.4% | 1.9% | 1.6% |
| Southern Hemisphere | 0.1% | 0.0% | 0.1% | 0.0% | 0.2% | 0.4% |
By manufacturer
Between 2014 and 2019, the global market share of plug-in hybrids was largely led by BYD Auto. The company then saw its global plug-in hybrid market share increasing from 6.0% in 2020 to 39.1% in 2024. Geely Holding was the second largest plug-in hybrid vehicle manufacturer in the world in 2025 with 9.2% share.
Due to the rapid growth of the plug-in hybrid vehicle market in China, manufacturers from outside China experienced decline in global plug-in hybrid market share. Volkswagen Group's global plug-in hybrid share peaked at 16.4% in 2020 before declining steadily to 4.2% in 2024. BMW's share followed a similar pattern, dropping from 9.8% in 2021 to 2.2% in 2024. Stellantis reached its highest share of 8.1% in 2021 but fell to 4.3% in 2024. Toyota's share of plug-in hybrids decreased over time, from 9.9% in 2019 to 2.4% in 2024. Hyundai's share fell from 6.4% in 2019 to 1.7% in 2024.
+Manufacturers by global plug-in hybrid market share |
| BYD Auto | 14.6% | 6.0% | 15.5% | 35.5% | 36.2% | 39.1% | 33.5% |
| Geely Holding | 11.6% | 11.3% | 9.3% | 7.6% | 7.3% | 7.4% | 9.2% |
| Chery | 0.1% | 0.1% | 0.1% | 1.4% | 2.7% | 4.2% | 7.0% |
| Li Auto | 0.2% | 3.8% | 5.1% | 5.0% | 9.4% | 7.9% | 5.7% |
| Changan Automobile | 0.0% | 0.0% | 1.6% | 5.3% | 5.0% | 5.5% | 5.8% |
| Volkswagen Group | 4.5% | 16.4% | 14.7% | 7.0% | 5.6% | 3.9% | 5.2% |
| Seres Auto | | | | | 2.4% | 6.1% | 4.8% |
| Great Wall Motor | 0.1% | 0.1% | 1.0% | 3.9% | 3.9% | 4.0% | 4.7% |
| BMW | 11.9% | 12.4% | 9.8% | 6.2% | 3.8% | 2.2% | 2.6% |
| Dongfeng Motor Group | 0.4% | 0.2% | 0.9% | 3.9% | 1.2% | 1.8% | 2.6% |
| Mercedes-Benz Group | 5.2% | 13.6% | 8.5% | 4.8% | 3.0% | 2.2% | 2.5% |
| Stellantis | 1.1% | 6.2% | 8.1% | 7.4% | 6.3% | 3.1% | 2.3% |
| Toyota | 9.9% | 4.2% | 5.4% | 2.4% | 2.3% | 1.8% | 2.2% |
| SAIC Motor | 11.6% | 6.3% | 5.0% | 3.5% | 2.2% | 2.5% | 2.1% |
| Leapmotor | 0.9% | 0.9% | 0.9% | 0.9% | 1.2% | 1.1% | 1.5% |
| Hyundai Motor Group | 6.4% | 6.4% | 5.7% | 4.4% | 2.7% | 1.4% | 1.3% |
| BAIC Group | | 0.2% | 0.5% | 0.9% | 0.0% | 0.1% | 0.8% |
| GAC Group | 0.6% | 0.0% | 0.1% | 0.3% | 0.8% | 0.8% | 0.7% |
| General Motors | 1.4% | 0.0% | 0.0% | 0.0% | 0.0% | 0.5% | 0.7% |
Government support and public deployment
Subsidies and economic incentives
Several countries have established grants and tax credits for the purchase of new plug-in electric vehicles (PEVs) including plug-in hybrid electric vehicles, and usually the economic incentive depends on battery size. The U.S. offers a federal income tax credit up to ,
Other government support
- United States
Incentives for the development of PHEVs are included in the Energy Independence and Security Act of 2007.[Evarts, E. (January 11, 2008) "Charge! Fuel economy law promotes plug-in hybrids," Consumer Reports Cars Blog. Retrieved January 15, 2008.] The Energy Improvement and Extension Act of 2008, signed into law on October 3, 2008, grants a tax credits for the purchase of PHEVs. President Barack Obama's New Energy for America calls for deployment of 1 million plug-in hybrid vehicles by 2015,
The American Recovery and Reinvestment Act of 2009
In March 2009, as part of the American Recovery and Reinvestment Act, the US Department of Energy announced the release of two competitive solicitations for up to $2 billion in federal funding for competitively awarded cost-shared agreements for manufacturing of advanced batteries and related drive components as well as up to $400 million for transportation electrification demonstration and deployment projects. This announcement will also help meet the President Barack Obama's goal of putting one million plug-in hybrid vehicles on the road by 2015.
Public deployments also include:
-
USDOE's FreedomCAR. US Department of Energy announced it would dole out $30 million in funding to three companies over three years to further the development of plug-in hybrids
-
USDOE announced the selection of Navistar Corporation for a cost-shared award of up to $10 million to develop, test, and deploy plug-in hybrid electric (PHEV) school buses.
-
DOE and Sweden have a MOU to advance market integration of plug-in hybrid vehicles
-
PHEV Research Center
-
San Francisco Mayor Gavin Newsom, San Jose Mayor Chuck Reed and Oakland, California Mayor Ron Dellums announced a nine-step policy plan for transforming the Bay Area into the "Electric Vehicle (EV) Capital of the U.S."
[ (more information in Plug-in hybrids in California).
]
-
Washington state PHEV Pilot Project
-
Texas Governor Rick Perry's proposal for a state $5,000 tax credit for PHEVs in "non-attainment" communities
-
Seattle, that includes City's public fleet converted vehicles, the Port of Seattle, King County and the Puget Sound Clean Air Agency
- European Union
Electrification of transport (electromobility) is a priority in the European Union Research Programme. It also figures prominently in the European Economic Recovery Plan presented November 2008, in the frame of the Green Car Initiative. DG TREN will support a large European "electromobility" project on electric vehicles and related infrastructure with a total budget of around €50 million as part of the Green Car Initiative.
Supportive organizations
Organizations that support plug-in hybrids include the World Wide Fund for Nature,
Other supportive organizations are Plug In America, the Alliance for Climate Protection, Friends of the Earth, the Rainforest Action Network, Rocky Mountain Institute (Project Get Ready),
FPL and Duke Energy has said that by 2020 all new purchases of fleet vehicles will be plug-in hybrid or all-electric.
See also
Further reading
-
American Council for an Energy-Efficient Economy, Plug-in Electric Vehicles: Challenges and Opportunities, June 2013
-
Argonne National Laboratory, Cradle-to-Grave Lifecycle Analysis of U.S. Light-Duty Vehicle-Fuel Pathways: A Greenhouse Gas Emissions and Economic Assessment of Current (2015) and Future (2025–2030) Technologies (includes estimated cost of avoided GHG emissions from BEVs and PHEVs), June 2016.
-
-
International Council on Clean Transportation, Driving Electrification – A Global Comparison of Fiscal Incentive Policy for Electric Vehicles, May 2014
-
International Energy Agency (IEA) and Electric Vehicles Initiative (April 2013), Global EV Outlook 2013 – Understanding the Electric Vehicle Landscape to 2020
-
International Energy Agency (IEA) – IA-HEV (May 2013), Hybrid and Electric Vehicles – The Electric Drive Gains Traction
-
Lee, Henry, and Grant Lovellette (2011). Will Electric Cars Transform the U.S. Vehicle Market? Belfer Center, Harvard University
-
-
-
Romm, Joseph J. and Fox-Penne, Peter. (2007). Plugging into the Grid: How Plug-In Hybrid-Electric Vehicles Can Help Break America's Oil Addiction and Slow Global Warming. Progressive Policy Institute.
-
U.S. Environmental Protection Agency, Application of Life-Cycle Assessment to Nanoscale Technology: Lithium-ion Batteries for Electric Vehicles, April 2013.
-
US Office of Energy Efficiency and Renewable Energy
-
US National Highway Traffic Safety Administration
External links
(
Automotive Technologies
)
