A plug-in hybrid electric vehicle (PHEV), plug-in hybrid vehicle (PHV), or plug-in hybrid is a hybrid vehicle which utilizes rechargeable batteries, or another energy storage device, that can be restored to full charge by connecting a plug to an external electric power source (usually a normal electric wall socket). A PHEV shares the characteristics of both a conventional hybrid electric vehicle, having an electric motor and an internal combustion engine (ICE); and of an all-electric vehicle, having a plug to connect to the electrical grid. Most PHEVs on the road today are passenger cars, but there are also PHEV versions of commercial vehicles and vans, utility trucks, buses, trains, motorcycles, scooters, and military vehicles.
The cost for electricity to power plug-in hybrids for all-electric operation has been estimated at less than one quarter of the cost of gasoline in California. Compared to conventional vehicles, PHEVs reduce air pollution locally and dependence on petroleum. PHEVs may reduce greenhouse gas emissions that contribute to global warming, compared with conventional vehicles. PHEVs also eliminate the problem of range anxiety associated with all-electric vehicles, because the combustion engine works as a backup when the batteries are depleted, giving PHEVs driving range comparable to other vehicles with gasoline tanks. Plug-in hybrids use no fossil fuel at the point of use during their all-electric range. Greenhouse gas emissions attributable to operation of plug-in hybrids during their all-electric range depend on the type of power plant that is used to meet additional demand on the electrical grid at the time and place where the batteries are charged. (See Greenhouse gas emissions, below.) If the batteries are charged directly from renewable sources off the electrical grid, then the greenhouse gas emissions are essentially zero. Other benefits include improved national energy security, fewer fill-ups at the filling station, the convenience of home recharging, opportunities to provide emergency backup power in the home, and vehicle-to-grid (V2G) applications. Several countries, including the United States and several European countries, have enacted laws to facilitate the introduction of PHEVs through grants and tax credits, emissions mandates, and by financing research and development of advanced batteries and other related technologies.
Chinese battery manufacturer and automaker BYD Auto released the F3DM to the Chinese fleet market in December 2008 and began sales to the general public in Shenzhen in March 2010. General Motors began deliveries of the Chevrolet Volt in the United States in December 2010, becoming the first plug-in hybrid available for retail sales in the American market. As of October 2014[update], the number of series production highway legal plug-in hybrids available for retail sales is limited to over 15 models, including some limited production luxury sport cars, and available mainly in the United States, Canada, Western European countries, Japan and China.
As of September 2014[update], about 248,000 highway-capable plug-in hybrid electric cars have been sold worldwide since December 2008. The Chevrolet Volt family, including its siblings Opel/Vauxhall Ampera, is the world's best selling plug-in hybrid with combined sales of over 77,000 units by June 2014. The Toyota Prius PHV is the second top selling plug-in hybrid with global sales of about 60,000 units sold, followed by the Mitsubishi Outlander P-HEV with about 33,000 units. As of June 2014[update], the United States is the market segment leader, with over 126,000 plug-in hybrids delivered, followed by the Netherlands with more than 32,000 units, and Japan with about 31,000 units.
- 1 Terminology
- 2 History
- 3 Technology
- 4 Target market
- 5 Advantages
- 6 Disadvantages
- 7 Greenhouse gas emissions
- 8 Production and sales
- 9 See also
- 10 References
- 11 External links
A plug-in hybrid's all-electric range is designated by PHEV-[miles] or PHEV[kilometers]km in which the number represents the distance the vehicle can travel on battery power alone. For example, a PHEV-20 can travel twenty miles (32 km) without using its combustion engine, so it may also be designated as a PHEV32km.
The Energy Independence and Security Act of 2007 defines a plug-in electric drive vehicle as a vehicle that:
- draws motive power from a battery with a capacity of at least 4 kilowatt hours;
- can be recharged from an external source of electricity for motive power; and
- is a light-, medium-, or heavy-duty motor vehicle or nonroad vehicle.
The Institute of Electrical and Electronics Engineers (IEEE) defines PHEVs similarly, but also requires that the hybrid electric vehicle be able to drive at least ten miles (16 km) in all-electric mode (PHEV-10; PHEV16km), while consuming no gasoline or diesel fuel.
The California Air Resources Board uses the term "off-vehicle charge capable" (OVCC) to mean having the capability to charge a battery from an off-vehicle electric energy source that cannot be connected or coupled to the vehicle in any manner while the vehicle is being driven.
Other popular terms sometimes used for plug-in hybrids are "grid-connected hybrids", "Gas-Optional Hybrid Electric Vehicle" (GO-HEV) or simply "gas-optional hybrids". General Motors is calling its Chevrolet Volt series plug-in hybrid an "Extended-Range Electric Vehicle".
The Lohner-Porsche Mixte Hybrid, produced as early as 1899, was the first hybrid electric car. Early hybrids could be charged from an external source before operation. However, the term "plug-in hybrid" has come to mean a hybrid vehicle that can be charged from a standard electrical wall socket. The term itself was coined by UC Davis Professor Andrew Frank, who has been called the "father of the plug-in hybrid." The July 1969 issue of Popular Science featured an article on the General Motors XP-883 plug-in hybrid. The concept commuter vehicle housed six 12-volt lead–acid batteries in the trunk area and a transverse-mounted DC electric motor turning a front-wheel drive. The car could be plugged into a standard North American 120 volt AC outlet for recharging.
In 2003, Renault began selling the Elect'road, a plug-in series hybrid version of their popular Kangoo, in Europe. It was sold alongside Renault's "Electri'cité" electric-drive Kangoo battery electric van. The Elect'road had a 150 km (93 mi) range using a nickel-cadmium battery pack and a 500 cc (31 cu in), 16 kilowatt liquid-cooled gasoline "range-extender" engine. It powered two high voltage/high output/low volume alternators, each of which supplied up to 5.5 kW at 132 volts at 5000 rpm. The operating speed of the internal combustion engine—and therefore the output delivered by the generators—varied according to demand. The fuel tank had a capacity of 10 liters (2.6 U.S. gal; 2.2 imp gal) and was housed within the right rear wheel arch. The range extender function was activated by a switch on the dashboard. The on-board 3.5 kilowatt charger could charge a depleted battery pack to 95% charge in about four hours from a 240 volts supply. Passenger compartment heating was powered by the battery pack as well as an auxiliary coolant circuit that was supplied by the range extender engine. After selling about 500 vehicles, primarily in France, Norway and the UK, at a price of about €25,000, the Elect'road was redesigned in 2007.
In September 2004, CalCars converted a 2004 Toyota Prius into a prototype of what it called the PRIUS+. With the addition of 130 kg (300 lb) of lead–acid batteries, the PRIUS+ achieved roughly double the fuel economy of a standard Prius and could make trips of up to 15 km (9 mi) using only electric power. The vehicle, which is owned by CalCars technical lead Ron Gremban, is used in daily driving, as well as a test bed for various improvements to the system.
On July 18, 2006, Toyota announced that it "plans to develop a hybrid vehicle that will run locally on batteries charged by a household electrical outlet before switching over to a gasoline engine for longer hauls." In April 2007 Toyota said it planned to migrate to lithium-ion batteries in future hybrid models, but not in the 2009 model year Prius. Lithium-ion batteries are expected to significantly improve fuel economy, and have a higher energy-to-weight ratio, but cost more to produce, and raise safety concerns due to high operating temperatures.
On November 29, 2006, GM announced plans to introduce a production plug-in hybrid version of Saturn's Greenline Vue SUV with an all-electric range of 10 mi (16 km). The model's sale is anticipated by third quarter 2009,[dated info] and GM announced in January 2007 that contracts had been awarded to two companies to design and test lithium-ion batteries for the vehicle. GM has said that they plan on introducing plug-in and other hybrids "for the next several years".
In January 2007, GM unveiled the prototype of the Chevrolet Volt, which was expected to feature a plug-in capable, battery-dominant series hybrid architecture called E-Flex. Future E-Flex plug-in hybrid vehicles may use gasoline, diesel, or hydrogen fuel cell power to supplement the vehicle's battery. General Motors envisions an eventual progression of E-Flex vehicles from plug-in hybrids to pure electric vehicles, as battery technology improves.
On July 25, Japan's Ministry of Land, Infrastructure and Transport certified Toyota's plug-in hybrid for use on public roads, making it the first automobile to attain such approval. Toyota plans to conduct road tests to verify its all-electric range. The Prius Plug-in Hybrid was said to have an all-electric range of 13 km (8 mi).
On August 9, 2007, General Motors vice-president Robert Lutz announced that GM is on track for Chevrolet Volt road testing in 2008 and production to begin by 2010. The Volt was designed with all-electric range of 40 mi (64 km). On September 5, Quantum Technologies and Fisker Coachbuild, LLC announced the launch of a joint venture in Fisker Automotive. Fisker intended to build a US$80,000 luxury PHEV-50, the Fisker Karma, initially scheduled for late 2009.
In September 2007, Aptera Motors announced their Typ-1 two-seater. They planned to produce both an electric 2e and a plug-in series hybrid 2h with a common three-wheeled, composite body design. As of 2009, over two thousand hybrid pre-orders had been accepted and production of the hybrid configuration was expected to begin in 2010. However, the company folded in December 2011.
On October 9, 2007, Chinese manufacturer BYD Automobile Company (which is owned by China's largest mobile phone battery maker) announced that it would be introducing a production PHEV-60 sedan in China in the second half of 2008. BYD exhibited it January 2008 at the North American International Auto Show in Detroit. Based on BYD's midsize F6 sedan, it uses lithium iron phosphate (LiFeP04)-based batteries instead of lithium-ion, and can be recharged to 70% of capacity in just 10 minutes.
On December 2007 Ford delivered the first Ford Escape Plug-in Hybrid of a fleet of 20 demonstration PHEVs to Southern California Edison. As part of this demonstration program Ford also developed the first ever flexible-fuel plug-in hybrid SUV, which was delivered in June 2008. This demonstration fleet of plug-ins has been in field testing with utility company fleets in the U.S. and Canada, and during the first two years since the program began, the fleet has logged more than 75,000 miles. On August 2009 Ford delivered the first Escape Plug-in equipped with intelligent vehicle-to-grid (V2G) communications and control system technology, and Ford plans to equip all 21 plug-in hybrid Escapes with the vehicle-to-grid communications technology. Sales of the Escape PHEV are scheduled for 2012.
On March 27, the California Air Resources Board modified their regulations, requiring automobile manufacturers to produce 58,000 plug-in hybrids during 2012 through 2014. 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. On June 26, Volkswagen announced that they would be introducing production plug-ins based on the Golf compact. Volkswagen uses the term 'TwinDrive' to denote a PHEV. In September, Mazda was reported to be planning PHEVs. On September 23, Chrysler announced that they had prototyped a plug-in Jeep Wrangler and a Chrysler Town and Country mini-van, both PHEV-40s with series powertrains, and an all-electric Dodge sports car, and said that one of the three vehicles would go into production.
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. 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.
On December 15, 2008 BYD Auto began selling its F3DM in China, becoming the first production plug-in hybrid sold in the world, though initially was available only for corporate and government customers. Sales to the general public began in Shenzhen in March 2010, but because the F3DM nearly doubles the price of cars that run on conventional fuel, BYD expects subsidies from the local government to make the plug-in affordable to personal buyers.
A global demonstration program involving 600 Toyota Prius Plug-in pre-production test cars began in late 2009 in Japan and by mid-2010 field testing had begun in France, Germany, the United Kingdom, Canada, and the United States.
Volvo Cars, in a joint venture with Vattenfall, a Swedish energy company, began a demonstration project with two Volvo V70 Plug-in Hybrids in Göteborg, Sweden since December 2009. As reported by the test drivers, the V70 Plug-in Hybrid demonstrators have an all-electric range between 20 kilometres (12 mi) to 30 kilometres (19 mi). The test plug-in hybrids were built with a button to allow test drivers to manually choose between electricity or diesel engine power at any time. Volvo announced series production of plug-in diesel-electric hybrids as early as 2012. Volvo claimed that its plug-in hybrid could achieve 125 miles per US gallon (1.88 L/100 km; 150 mpg-imp), based on the European test cycle.
On October 2010 Lotus Engineering unveiled the Lotus CityCar at the 2010 Paris Motor Show, a plug-in series hybrid concept car designed for flex-fuel operation on ethanol, or methanol as well as regular gasoline. The lithium battery pack provides an all-electric range of 60 kilometres (37 mi), and the 1.2-liter flex-fuel engine kicks in to allow to extend the range to more than 500 kilometres (310 mi).
GM officially launched the Chevrolet Volt in the U.S. on November 30, 2010, and retail deliveries began in December 2010. Its sibling the Opel/Vauxhall Ampera was launched in Europe between late 2011 and early 2012. The first deliveries of the Fisker Karma took place in July 2011, and deliveries to retail customers began in November 2011. The Toyota Prius Plug-in Hybrid was released in Japan in January 2012, followed by the United States in February 2012. Deliveries of the Prius PHV in Europe began in late June 2012. The Ford C-Max Energi was released in the U.S. in October 2012, the Volvo V60 Plug-in Hybrid in Sweden by late 2012.
The Honda Accord Plug-in Hybrid was released in selected U.S. markets in January 2013, and the Mitsubishi Outlander P-HEV in Japan in January 2013, becoming the first SUV plug-in hybrid in the market. Deliveries of the Ford Fusion Energi began in February 2013. BYD Auto stopped production of its BYD F3DM due to low sales, and its successor, the BYD Qin, began sales in Costa Rica in November 2013, with sales in other countries in Latin America scheduled to begin in 2014. Qin deliveries began in China in mid December 2013. Deliveries to retail customers of the limited edition McLaren P1 supercar began in the UK in October 2013, and the Porsche Panamera S E-Hybrid began deliveries in the U.S. in November 2013. The first retail deliveries of the Cadillac ELR took place in the U.S. in December 2013. The BMW i8 and the limited edition Volkswagen XL1 were released to retail customers in Germany in June 2014. The Porsche 918 Spyder was also released in Europe and the U.S. in 2014. The first units of the Audi A3 Sportback e-tron and Volkswagen Golf GTE were registered in Germany in August 2014.
Other plug-in vehicles slated to the market between 2014 and 2015 are the Porsche Cayenne S E-Hybrid, Mercedes-Benz S 500 Plug-in Hybrid, Volvo XC90 Plug-in Hybrid and Volkswagen Passat GTE. The second generation Chevrolet Volt is scheduled to be unveiled at the January 2015 North American International Auto Show. The next generation Volt will be released as a 2016 model year.
Series hybrids use an internal combustion engine (ICE) to turn a generator, which in turn supplies current to an electric motor, which then rotates the vehicle’s drive wheels. A battery or supercapacitor pack, or a combination of the two, can be used to store excess charge. Examples of series hybrids vehicles include the Chevrolet Volt, Fisker Karma, Renault Kangoo, Elect'Road, Toyota's Japan-only Coaster light-duty passenger bus, Daimler AG's hybrid Orion bus, Opel Flextreme concept car, Swissauto REX VW Polo prototype and many diesel-electric locomotives. With an appropriate balance of components this type can operate over a substantial distance with its full range of power without engaging the ICE. As is the case for other architectures, series hybrids can operate without recharging as long as there is liquid fuel in the tank.
Parallel hybrids, such as Honda's Insight, Civic, and Accord hybrids, can simultaneously transmit power to their drive wheels from two distinct sources—for example, an internal combustion engine and a battery-powered electric drive. Although most parallel hybrids incorporate an electric motor between the vehicle's engine and transmission, a parallel hybrid can also use its engine to drive one of the vehicle's axles, while its electric motor drives the other axle and/or a generator used for recharging the batteries. This type is called a road-coupled hybrid. The Audi Duo plug-in hybrid concept car is an example of this type of parallel hybrid architecture. Parallel hybrids can be programmed to use the electric motor to substitute for the ICE at lower power demands as well as to substantially increase the power available to a smaller ICE, both of which substantially increase fuel economy compared to a simple ICE vehicle.
Series-parallel hybrids have the flexibility to operate in either series or parallel mode. Hybrid powertrains currently used by Ford, Lexus, Nissan, and Toyota, which some refer to as “series-parallel with power-split,” can operate in both series and parallel mode at the same time. As of 2007, most plug-in hybrid conversions of conventional hybrids utilize this architecture. The Toyota Prius Plug-in Hybrid operates as a series-parallel hybrid.
Batteries are DC devices while grid power is AC. In order to charge the batteries, a DC charger must be utilized. The charger can be located in several locations:
On-board chargers are mounted inside the vehicle. Since the charger takes up space and adds weight, its power capacity is generally limited by practical considerations, avoiding carrying a more powerful charger that can only be fully utilized at certain locations. However, carrying the charger along with the vehicle ensures that power will be available anywhere a power connection can be found.
Off-board chargers can be as large as needed and mounted at fixed locations, like the garage or dedicated charging stations. Built with dedicated wiring, these chargers can handle much more power and charge the batteries more quickly. However, as the output of these chargers is DC, each battery system requires the output to be changed for that car. Modern charging stations have a system for identifying the voltage of the battery pack and adjusting accordingly.
Using 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 zero additional weight or size. AC Propulsion uses this charging method, referred to as "reductive charging".
Modes of operation
Regardless of its architecture, a plug-in hybrid may be capable of 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 engaged. 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.
- Blended mode is a kind of charge-depleting mode. It is normally employed by vehicles which do not have enough electric power to sustain high speeds without the help of the internal combustion portion of the powertrain. A blended control strategy typically increases the distance from stored grid electricity compared to a charge-depleting strategy. The Renault Kangoo and some Toyota Prius conversions are examples of vehicles that use this mode of operation. The Electri'cité and Elect'road versions of the Kangoo were charge-depleting battery electric vehicles: the Elect'road had a modest internal combustion engine which extended its range somewhat. Conversions of 2004 and later model Toyota Prius can only run without using the ICE at speeds of less than about 42 mph (68 km/h) due to the limits dictated by the vehicle's powertrain control software. However, at faster speeds electric power can still be used to displace gasoline, thus improving the fuel economy in blended mode and generally doubling the fuel efficiency.
Charge-sustaining mode is used by production hybrid vehicles (HEVs) today, and combines the operation of the vehicle's two power sources in such a manner that the vehicle is operating as efficiently as possible without allowing the battery state of charge to move outside a predetermined narrow band. Over the course of a trip in a HEV the state of charge may fluctuate but will have no net change. The battery in a HEV can thus be thought of as an energy accumulator rather than a fuel storage device. Once a plug-in hybrid has exhausted its all-electric range in charge-depleting mode, it can switch into charge-sustaining mode automatically.
Mixed mode describes a trip in which a combination of the above modes are utilized. For example, a PHEV-20 Prius conversion may begin a trip with 5 miles (8 km) of low speed charge-depleting, then get onto a freeway and operate in blended mode for 20 miles (32 km), using 10 miles (16 km) worth of all-electric range at twice the fuel economy. Finally the driver might exit the freeway and drive for another 5 miles (8 km) without the internal combustion engine until the full 20 miles (32 km) of all-electric range are exhausted. At this point the vehicle can revert to a charge sustaining-mode for another 10 miles (16 km) until the final destination is reached. Such a trip would be considered a mixed mode, as multiple modes are employed in one trip. This contrasts with a charge-depleting trip which would be driven within the limits of a PHEV's all-electric range. Conversely, the portion of a trip which extends beyond the all-electric range of a PHEV would be driven primarily in charge-sustaining mode, as used by a conventional hybrid.
Electric power storage
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. However, some authors argue that PHEVs will soon become standard in the automobile industry. Design issues and trade-offs against battery life, capacity, heat dissipation, weight, costs, and safety need to be solved. Advanced battery technology is under development, promising greater energy densities by both mass and volume, and battery life expectancy is expected to increase.
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. The price premium for early 2007 conventional hybrids is about US$5000, some US$3000 of which is for their NiMH battery packs. At early 2007 gasoline and electricity prices, that would mean a break-even point after six to ten years of operation. The conventional hybrid premium could fall to US$2000 in five years, with US$1200 or more of that being cost of lithium-ion batteries, providing for a three-year payback. 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. However, plug-in hybrids typically use larger battery packs than comparable conventional hybrids, and thus require more resources. Pacific Gas and Electric Company (PG&E) has suggested that utilities could purchase used batteries for backup and load leveling purposes. They state that while these used batteries may be no longer usable in vehicles, their residual capacity still has significant value. 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."
Lithium iron phosphate (LiFePO4) is a class of cathode materials used in lithium iron phosphate batteries that is getting attention from the auto industry. Valence Technologies produce a lithium iron manganese phosphate (LiFeMnPO4) battery with LG Chem selling lithium iron phospate (LiFePO4) batteries for the Chevy Volt and A123 produces a lithium nano-phosphate battery. The most important merit of this battery type is safety and high-power. Lithium iron phosphate batteries are one of three major types in LFP family, the other two being nano-phosphate and nano-cocrystalline-olivine.
In France, Électricité de France (EDF) and Toyota are installing charging stations for PHEVs on roads, streets and parking lots. EDF is also partnering with Elektromotive, Ltd. to install 250 new charging points over six months from October 2007 in London and elsewhere in the UK. Recharging points also can be installed for specific uses, as in taxicab stands. Project Better Place began in October 2007 and is working with Renault on development of exchangeable batteries (battery swapping).
Ultracapacitors (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. The CSIRO's UltraBattery combines a supercapacitor and a lead acid battery in a single unit, creating a hybrid car battery that lasts longer, costs less and is more powerful than current technologies used in plug-in hybrid electric vehicles (PHEVs).
The optimum battery size varies depending on whether the aim is to reduce oil consumption, running costs, or emissions, but a recent study concluded that "The best choice of PHEV battery capacity depends critically on the distance that the vehicle will be driven between charges. Our results suggest that for urban driving conditions and frequent charges every 10 miles or less, a low-capacity PHEV sized with an AER (all electric range) of about 7 miles would be a robust choice for minimizing gasoline consumption, cost, and greenhouse gas emissions. For less frequent charging, every 20–100 miles, PHEVs release fewer GHGs, but HEVs are more cost effective. "
Conversions of production vehicles
Conversion of fossil-fuel vehicles
Retrofit electrification requires only one-fifth the energy required to build a new vehicle. This is called ACEV-to-PHEV conversion. There are several companies that are converting fossil fuel non-hybrid vehicles (also called all-combustion engine vehicles) to plug-in hybrids:
Colorado is going to offer $6,000 credit for PHEV conversions (in addition to a federal 10% credit up to $4,000 for qualifying vehicles).
|This section requires expansion. (February 2009)|
Conversions of production hybrids
Aftermarket conversion of an existing production hybrid (a charge-maintaining hybrid) to a plug-in hybrid (called CHEV-to-PHEV conversion) typically involves increasing the capacity of the vehicle's battery pack and adding an on-board AC-to-DC charger. Ideally, the vehicle's powertrain software would be reprogrammed to make full use of the battery pack's additional energy storage capacity and power output.
Many early plug-in hybrid electric vehicle conversions have been based on the 2004 or later model Toyota Prius. Some of the systems have involved replacement of the vehicle's original NiMH battery pack and its electronic control unit. Others, such as A123 Hymotion, the CalCars Prius+, and the PiPrius, piggyback an additional battery back onto the original battery pack, this is also referred to as Battery Range Extender Modules (BREMs). Within the electric vehicle conversion community this has been referred to as a "hybrid battery pack configuration". Early lead–acid battery conversions by CalCars demonstrated 10 miles (15 km) of EV-only and 20 miles (30 km) of double mileage blended mode range.
EDrive Systems use Valence Technology Li-ion batteries and have a claimed 40 to 50 miles (64 to 80 km) of electric range. Other companies offering plug-in conversions or kits for the Toyota Prius (some of them also for Ford Escape Hybrid) include Hymotion, Hybrids Plus Manzanita Micro and OEMtek BREEZ (PHEV-30). AFS Trinity's XH-150 claims that it has created a functioning plug-in hybrid with a 40 miles (64 km) all-electric range and that it has solved the overheating problem that rapid acceleration can cause in PHEVs and extend battery life.
The EAA-PHEV project was conceived by CalCars and the Electric Auto Association in October 2005 to accelerate efforts to document existing HEVs and their potential for conversion into PHEVs. It includes a "conversion interest" page. The Electric Auto Association-PHEV "Do-It-Yourself" Open Source community's primary focus is to provide conversion instructions to help guide experienced converters through the process, and to provide a common design that could demonstrate multiple battery technologies. Many members of organizations such as CalCars and the EAA as well as companies like Hybrids Plus, Hybrid Interfaces of Canada, and Manzanita Micro participate in the development of the project.
Plug-In Supply, Inc. of Petaluma, California offers components and assemblies to build the Prius+, the plug-in conversion invented by CalCars. Their lead–acid battery box assembly forms a complete install package, providing access to the spare tire and containing twenty 12 volt lead–acid batteries and all high voltage components and control electronics. The "PbA Battery Box Assembly" is also available without batteries. It provides about 10 miles (16 km) of EV mode range. Conversion time was reduced by plug-in supply to one day.
Oemtek offers a Valence powered lithium iron phosphate conversion that should provide 50 miles (80 km) of all-electric range. The Motor Industry Research Association has announced a retrofit hybrid conversion kit that provides removable battery packs that plug into a wall outlet for charging. Poulsen Hybrid is developing a conversion kit that will add through-the-road plug-in hybrid capability to conventional vehicles by externally mounting electric motors onto two of the wheels.
MD-Tech offers a PHEV Kit for hybrid vehicles that acts as a hybrid battery re-charger. The kit supplies power to the hybrid battery without modifying the powertrain of the hybrid vehicle. It fits into the back of a hybrid vehicle, originally designed to fit under the rear floor of a Toyota Prius. The kit uses lithium iron phosphate cells in a battery supplying 4 kWh of energy. This gives it a range of 30 km in charge-depleting, EV mode and provides a boost of power in blended mode. The battery charger uses mains electricity and takes 4–5 hours to charge. The battery supplies power to the DC to DC boost converter which regulates power to the hybrid battery. The converter output can be adjusted to set voltage and current output. A proprietary battery management system uses active battery balancing to monitor the battery state of health.
Enginer Inc. of Troy, Michigan offers universal plugin conversion kits with components and assemblies to build two stage hybrid battery system. Their lithium-ion battery box assembly forms a complete install package, providing access to the spare tire and containing 16/32 lithium phosphate battery cells, a DC/DC converter, a BMS and a charger. It provides about 10 miles (16 km) of EV mode range for under $2000 (2 kWh model). Longer range 4 kWh model is also available for $1000 more. Conversion time was reduced to two/three hours.
With the exception of Tesla Motors, demand for all-electric vehicles, especially in the U.S. market, has been driven by government incentives. In particular, American sales of the Nissan Leaf have depended on generous incentives and special treatment in the state of Georgia, the top selling Leaf market. According to international market research, 60% of respondents believe a battery driving range of less than 160 km (99 mi) is unacceptable even though only 2% drive more than that distance per day. Among popular current all-electric vehicles, only the Tesla (with the most expensive version of the Model S offering a 265 miles (426 km) range in the U.S. Environmental Protection Agency 5-cycle test) significantly exceeds this threshold. The Nissan Leaf has an EPA rated range of 75 miles (121 km) for the 2013 model year.
Plug-in hybrids provide the extended range and potential for refueling of conventional hybrids while enabling drivers to utilize 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 11.8 miles (19.0 km), while the average distance commuted to work in England and Wales in 2011 was slightly lower at 15 km (9.3 mi). Since building a PHEV with a longer all-electric range adds weight and cost, and reduces cargo and/or passenger space, there is not a specific all-electric range that is optimal. The accompanying graph shows the observed all-electric range, in miles, for four popular U.S. market plug-in hybrids, as tested by Popular Mechanics magazine.
A key design parameter of the Chevrolet Volt was a target of 40 miles (64 km) for the all-electric range, selected to keep the battery size small and lower costs, and mainly because research showed that 78% of daily commuters in the U.S. travel 40 mi (64 km) 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 16 kW·h 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 2014 edition of the EPA's annual report "Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends" estimates the following utility factors 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, and 29% for the Toyota Prius PHV.
Between January and August 2014, a period during which US sales of conventional hybrids slowed, US sales of plug-in hybrids grew from 28,241 to 40,748 compared to the same period in 2013. US sales of all-electric vehicles also grew during the same period: from 29,917 vehicles in the January to August 2013 period to 40,349 in January to August 2014.
Energy resilience and petroleum displacement
Each kilowatt hour of battery capacity in use will displace up to 50 U.S. gallons (190 l; 42 imp gal) of petroleum fuels per year (gasoline or diesel fuels). Also, electricity is multi-sourced and, as a result, it gives the greatest degree of energy resilience.
The actual fuel economy for PHEVs depends on their powertrain operating modes, their 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 35 miles (56 km), and an additional gasoline-only extended range of 344 miles (554 km) has an EPA combined city/highway fuel economy of 93 MPG-e in all-electric mode, and 37 mpg-US (6.4 L/100 km; 44 mpg-imp) in gasoline-only mode, for an overall combined gas-electric fuel economy rating of 60 mpg-US (3.9 L/100 km; 72 mpg-imp) equivalent (MPG-e). The EPA also included in the Volt's fuel economy label a table showing fuel economy and electricity consumed for five different scenarios: 30, 45, 60 and 75 miles (121 km) driven between a full charge, and a never charge scenario. According to this table the fuel economy goes up to 168 mpg-US (1.40 L/100 km; 202 mpg-imp) equivalent (MPG-e) with 45 miles (72 km) 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. 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.
A further advantage of PHEVs is that they have 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 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-70 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. The actual efficiency achieved depends on losses from electricity generation, inversion, battery charging/discharging, the motor controller and motor itself, the way a vehicle is used (its duty cycle), and the opportunities to recharge by connecting to the electrical grid.
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. 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.
PHEV batteries also allow for an additional efficiency when converting solar power directly into a DC storage system, as opposed to converting the energy into AC home or building. DC to DC direct conversion is more efficient, therefore, potentially allowing the more efficient capture of solar energy.
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 30 miles (48 km) all-electric range, averaged only 51 mpg-US (4.6 L/100 km; 61 mpg-imp) in a 17,000-mile (27,000 km) test in Seattle, and similar results with the same kind of conversion battery models at Google's RechargeIT initiative. Moreover, the additional battery pack costs US$10,000–US$11,000.
The following table compares EPA's estimated out-of-pocket fuel costs and fuel economy ratings of all the plug-in hybrid electric vehicles rated by EPA in the U.S. since 2010 up to October 2014 versus the most fuel efficient gasoline-electric hybrid car, the Toyota Prius third generation, and EPA's average new 2013/14 vehicle, which has a fuel economy of 23 mpg-US (10 L/100 km; 28 mpg-imp). The table also shows the fuel efficiency for plug-in hybrids in all-electric mode expressed as KW-hrs/100 mile, the metric used by EPA to rate electric cars before November 2010.
|Comparison of out-of-pocket fuel costs and fuel economy for automobiles
rated by EPA as of October 2014[update] with MPGe and conventional MPG(1)
(as displayed in the Monroney label and the US DoE fueleconomy.gov website)
|BMW i3 REx||2014||Electricity only
(29 kW-hrs/100 mi)
|97/79 mpg-e||88 mpg-e||$0.87||$700||The EPA classifies the i3 REx as a
series plug-in hybrid while CARB as a
range-extended battery-electric vehicle (BEVx).
The 2014 i3 REx is the most fuel efficient
EPA-certified current year vehicle with
a gasoline engine since 1984.
|39 mpg||41/37 mpg||$2.44|
|Honda Accord PHEV||2014||Electricity
(29 kW-hrs/100 mi)
|-||57 mpg-e||$1.36||$950||After the first 13 miles the car functions
like a regular hybrid. Depending on
driving style, the car may use both gasoline
and electricity during the first 13 miles.
|Gasoline only||46 mpg||47/46 mpg|
|Chevrolet Volt||2013/15||Electricity only
(35 kW-hrs/100 mi)
|Gasoline only||37 mpg||35/40 mpg||$2.57|
|Toyota Prius PHV||2013/15||Electricity
(29 kW-hrs/100 mi
plus 0.2 gallons/100 mi)
|-||58 mpg-e||$1.44||$950||After the first 11 miles the car functions
like a regular Prius hybrid
|Gasoline only||50 mpg||51/49 mpg||$1.74|
|Chevrolet Volt||2012||Electricity only||94 mpg-e
(36 kW-hrs/100 mi)
|95/93 mpg-e||60 mpg-e||$1.08||$1,000|
|Gasoline only||37 mpg||35/40 mpg||$2.57|
|Ford C-Max Energi
Ford Fusion Energi
(37 kW-hrs/100 mi)
|95/81 mpg-e||51 mpg-e||$1.36||$1,050||The Energi did not use any gasoline
for the first 20 mi in EPA tests,
but depending on the driving style,
the car may use both gasoline
and electricity during EV mode.
|Gasoline only||38 mpg||40/36 mpg||$2.29|
|Cadillac ELR||2014/15||Electricity only
(41 kW-hrs/100 mi)
|Gasoline only||33 mpg||31/35 mpg||$2.89|
(43 kW-hrs/100 mi)
|-||37 mpg-e||$2.19||$1,550||The i8 does not run on 100% electricity
as it consumes 0.1 gallons per 100 mi
in EV mode (all-electric range = 0 mi)
|Gasoline only||28 mpg||28/29 mpg||$3.40|
|Porsche 918 Spyder||2015||Electricity only
(50 kW-hrs/100 mi)
|Gasoline only||22 mpg||20/24 mpg||$4.33|
|Fisker Karma||2012||Electricity only
(62 kW-hrs/100 mi)
|Gasoline only||20 mpg||20/21 mpg||$4.76|
|Porsche Panamera S E-Hybrid||2014/15||Electricity
(52 kWh/100 mi)
|-||31 mpg-e||$3.49||$1,850||The all-electric range is between 0 to 15 mi.|
|Gasoline only||25 mpg||23/29 mpg||$3.81|
(25 kWh/100 mi)
|-||17 mpg-e||$5.38||$3,200||The P1 does not run on 100% electricity
as it consumes 4.8 gallons per 100 mi
in EV mode (all-electric range = 0 mi)
|Gasoline only||17 mpg||16/20 mpg||$5.60|
|50 mpg||51 mpg||48 mpg||$1.74||$1,050||Most fuel efficient gasoline-electric
hybrid car, together with the Prius c.
|Ford Taurus FWD 3.5L
(Average new car)
|2013/14||Gasoline only||23 mpg||19 mpg||29 mpg||$3.79||$2,300||Other 2013 models achieving 23 mpg
include the Chrysler 200, Toyota Venza,
and Hyundai Santa Fe Sport 2WD.
|Notes: (1) Based on 45% highway and 55% city driving. Electricity cost of US$0.12/kw-hr, premium gasoline price of US$3.81 per gallon (used by the Volt, Karma, i3 REx and Porsche 918 Spyder), and regular gasoline price of US$3.49 per gallon (as of 12 March 2014[update]). Conversion 1 gallon of gasoline=33.7 kW-hr. (Approx US$1.01 per litre premium and US$0.92 per litre regular)|
A study published in 2014 by researchers from Lamar University, Iowa State University and Oak Ridge National Laboratory compared the operating costs of plug-in hybrid electric vehicles (PHEVs) of various electric ranges (10, 20, 30, and 40 miles) with conventional gasoline vehicles and hybrid-electric vehicles (HEVs) for different payback periods, considering different charging infrastructure deployment levels and gasoline prices. The study concluded that:
- PHEVs save around 60% or 40% in energy costs, compared with conventional gasoline vehicles and HEVs, respectively. However, for drivers with significant daily vehicle miles traveled (DVMT), hybrid vehicles may be even a better choice than plug-in hybrids with a range of 40 mi (64 km), particularly when there is 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 US$4 per gallon to US$5 per gallon, the number of drivers who benefit from a larger battery increases significantly. If the gas price is US$3, a plug-in hybrid with a range of 10 mi (16 km) is the least costly option even if the battery cost is $200/kW.
- Although quick chargers can reduce charging time, they contribute little to energy cost savings for PHEVs, as opposed to Level-2 chargers.
Range anxiety elimination
One of the main barriers for the general adoption of all-electric cars is the range anxiety factor, the driver's fear of being stranded by a depleted battery before reaching the final destination. Plug-in hybrids, as opposed to pure electric cars, eliminate the range anxiety concerns because the gasoline engine serves as a back-up to recharge the battery to provide electric power to the electric motor, or to provide propulsion directly. Access to a regular fuel station guarantees that a PHEV has similar driving ranges as conventional gasoline-powered automobile.
As a response to range anxiety concerns, BMW is offering an optional limited capability gasoline range extender engine for its all-electric BMW i3. The range-extender option costs an additional US$3,850 in the United States, €4,710 (~ US$6,300) in France, and €4,490 (~ US$6,000) in the Netherlands. The range-extender option of the BMW i3 was designed to meet the California Air Resources Board (CARB) regulation for an auxiliary power unit (APU) called REx. According to rules adopted in March 2012 by CARB, the 2014 BMW i3 with a REx unit fitted will be the first car to qualify as a range-extended battery-electric vehicle or "BEVx." CARB describes this type of electric vehicle as "a relatively high-electric range battery-electric vehicle (BEV) to which an APU is added." The unit, which maintains battery charge at about 30% after the pack has been depleted in normal use, is strictly limited in the additional range it can provide.
One of the advantages of the plug-in hybrid design is that the generator can be completely decoupled from the traction. Unlike a conventional engine, which operates over a wide variety of power settings and operational conditions, the range extender can be operated under optimum conditions at all times. High-efficiency power sources that are not suitable for normal automotive use may be perfectly suitable for PEV use. These include advanced close-cycle steam engines, stirling engines, Wankel engines, and microturbines due primarily to their light weight and small size.
The Ontario Medical Association announced that smog is responsible for an estimated 9,500 premature deaths in its province every year. Plug-in hybrids in emission-free electric mode may contribute to the reduction of smog.
PHEVs and fully electric cars may allow for more efficient use of existing electric production capacity, much of which sits idle as operating reserve most of the time. This assumes that vehicles are charged primarily during off peak periods (i.e., at night), or equipped with technology to shut off charging during periods of peak demand. Another advantage of a plug-in vehicle is their potential ability to load balance or help the grid during peak loads. This is accomplished with vehicle-to-grid technology. By using excess battery capacity to send power back into the grid and then recharge during off peak times using cheaper power, such vehicles are actually advantageous to utilities as well as their owners. Even if such vehicles just led to an increase in the use of night time electricity they would even out electricity demand which is typically higher in the day time, and provide a greater return on capital for electricity infrastructure.
In the UK, VTG would need to comply with generation connection standard "G59/2", which means that it would need an earth rod at the premises, and would be unable to export more than 17 kW without the network firm's permission (which feeding onto one phase, i.e. for a normal house, would not be given - to maintain a balance of load across the three phases).
In October 2005, five Toyota engineers and one Asian AW engineer published an IEEE technical paper detailing a Toyota-approved project to add vehicle-to-grid capability to a Toyota Prius. Although the technical paper described "a method for generating voltage between respective lines of neutral points in the generator and motor of the THS-II (Toyota Hybrid System) to add a function for generating electricity", it did not state whether or not the experimental vehicle could be charged through the circuit, as well. However, the vehicle was featured in a Toyota Dream House, and a brochure for the exhibit stated that "the house can supply electricity to the battery packs of the vehicles via the stand in the middle of the garage", indicating that the vehicle may have been a plug-in hybrid.
In November 2005, more than 50 leaders from public power utility companies across the United States met at the Los Angeles Department of Water and Power headquarters to discuss plug-in hybrid and vehicle-to-grid technology. The event, which was sponsored by the American Public Power Association, also provided an opportunity for association members to plan strategies that public power utility companies could use to promote plug-in hybrid technology. Greg Hanssen and Peter Nortman of EnergyCS and EDrive attended the two-day session, and during a break in the proceedings, made an impromptu display in the LADWP parking lot of their converted Prius plug-in hybrid.
In September 2006, the California Air Resources Board held a Zero Emission Vehicle symposium that included several presentations on V2G technology. In April 2007, Pacific Gas and Electric Company showcased a PHEV at the Silicon Valley Leadership Alternative Energy Solutions Summit with vehicle-to-grid capability, and demonstrated that it could be used as a source of emergency home power in the event of an electrical power failure. Regulations intended to protect electricians against power other than from grid sources would need to be changed, or regulations requiring consumers to disconnect from the grid when connected to non-grid sources will be required before such backup power solutions would be feasible.
Jon Wellinghoff, from the US Federal Energy Regulatory Commission, coined the term "Cash-Back Hybrids" to describe payments to car owners for putting their batteries on the power grid. Batteries could also be offered in low-cost leasing or renting or by donation (including maintenance) to the car owners by the public utilities, in a vehicle-to-grid agreement.
Cost of batteries
Disadvantages of plug-in hybrids 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 US$1,700/kW·h of usable energy, and considering that a PHEV-10 requires about 2.0 kW·h and a PHEV-40 about 8 kW·h, the manufacturer cost of the battery pack for a PHEV-10 is around US$3,000 and it goes up to US$14,000 for a PHEV-40. According to the same study, even though costs are expected to decline by 35% by 2020, market penetration is expected to be slow and therefore PHEVs are not expected to significantly impact oil consumption or carbon emissions before 2030, unless a fundamental breakthrough in battery technologies occurs.
|Cost comparison between a PHEV-10 and a PHEV-40
(prices for 2010)
compared to conventional
upgrade at home
to a HEV
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 14.5 mi (23 km)
(2) Assuming 15,000 miles 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 a 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 US$1,300 per kilowatt hour in 2007 to US$500 per kilowatt hour in 2012. The U.S. Department of Energy has set cost targets for its sponsored battery research of US$300 per kilowatt hour in 2015 and US$125 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.
A study published in 2011 by the Belfer Center, Harvard University, found that the gasoline costs savings of plug-in electric cars 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. According to the study estimates, a PHEV-40 is US$5,377 more expensive than a conventional internal combustion engine, while a battery electric vehicle (BEV) is US$4,819 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 (US$1,155 to US$7,181 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.
Lithium iron phosphate batteries from Valence Technologies were used in the first plug-in hybrids from CalCars. They are providing a conversion for the Toyota Prius priced at US$12,000. Hymotion also offers a conversion for US$10,000 but their conversion is only 5 kW where Oemtek's is 9 kW.
Recharging outside home garages
Many authors have assumed that plug-in recharging will take place overnight at home. However, residents of cities, apartments, dormitories, and townhouses might not have garages or driveways with available power outlets, and they might be less likely to buy plug-ins unless recharging infrastructure is developed. Electrical outlets or charging stations near their places of residence, or in commercial or public parking lots or streets or workplaces are required for these potential users to gain the full advantage of PHEVs. Even house dwellers might need to charge at the office or to take advantage of opportunity charging at shopping centers. However, this infrastructure is not in place today and it will require investments by both the private and public sectors.
Several cities in California and Oregon, and particularly San Francisco and other cities in the San Francisco Bay Area and Silicon Valley, as well as some local private firms such as Google and Adobe Systems, already have deployed charging stations and have expansion plans to attend both plug-ins and all-electric cars. In Google's case, its Mountain View campus has 100 available charging stations for its share-use fleet of converted plug-ins available to its employees. Solar panels are used to generate the electricity, and this pilot program is being monitored on a daily basis, with performance results published on the RechargeIT website.
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. 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. Although clean coal technologies could create power plants which 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." Efficiency of plug-in hybrids is also impacted by the overall efficiency of electric power transmission. Transmission and distribution losses in the USA were estimated at 7.2% in 1995 and 6.5% in 2007. By life cycle analysis of air pollution emissions, natural gas vehicles are currently the lowest emitter.
Tiered rate structure for electric bills
Electric utility companies generally do not utilize flat rate pricing. For example, Pacific Gas and Electric (PG&E) normally charges $0.10 per kilowatt hour (kW·h) for the base tier, but additional tiers are priced as high as $0.30 per kW·h to customers without electric vehicles. Some utilities offer electric vehicle users a rate tariff that provides discounts for off-peak usage, such as overnight recharging. PG&E offers a special, discounted rate for plug-in and other electric vehicle customers, the "Experimental Time-of-Use Low Emission Vehicle rate." That tariff gives people much cheaper rates if they charge at night, especially during the summer months.
The additional electrical utilization required 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. Without an off-peak charging tariff, one study of a certain PHEV-20 model having an all-electric range of 20 miles, gasoline-fueled efficiency of 52.7 mi/gal U.S., and all-electric efficiency of 4 mi/kW·h, found that household electricity customers who consumed 131%–200% of baseline electricity at $0.220/(kW·h) would see benefits if gasoline was priced above US$2.89/US gal; those that consumed 201%–300% of baseline electricity at $0.303/(kW·h) would only see benefits if gas was priced above $3.98; and households consuming over 300% of baseline electricity at $0.346/(kW·h) would only see benefits if gasoline was priced above $4.55 (USD/gal). Off-peak tariff rates can lower the break-even point. The PG&E tariff would change those break-even gasoline prices to US$1.96, $3.17 and $3.80 per gallon, respectively, for the given PHEV and usage pattern in question.
Customers under such tariffs could see significant savings by being careful about when the vehicle was charged, for example, by using a timer to restrict charging to off-peak hours. Thus, an accurate comparison of the benefit requires each household to evaluate its current electrical usage tier and tariffs weighed against the cost of gasoline and the actual observed operational cost of electric mode vehicle operation.
Lithium availability and supply security
Current technology for plug-ins is based on the lithium-ion battery and an electric motor, and the demand for lithium, heavy metals and other rare elements (such as neodymium, boron and cobalt) required for the batteries and powertrain is expected to grow significantly due to the incoming market entrance of plug-ins and electric vehicles in the mid and long term. Some of the largest world reserves of lithium and other rare metals are located in countries with strong resource nationalism, unstable governments or hostile 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. Eventhough the metals used in electric vehicle batteries are rare, they can be recycled. Fossil fuels are finite and nonrenewable.
Currently, the main deposits of lithium are found in China and South America throughout the Andes mountain chain. In 2008 Chile was the leading lithium metal producer, followed by Australia, China, and Argentina. 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, which can be used to make lithium batteries for hybrid and electric vehicles. Other important reserves are located in Chile, China, and Brazil. Regarding rare earth elements, most reserves are located in China, which controls the world market for these elements.
Hazard to pedestrians
At low speeds, electric-drive cars produced less roadway noise as compared to vehicles propelled by internal combustion engines. Blind people or the visually impaired consider the noise of combustion engines a helpful aid while crossing streets, hence plug-in electric cars and hybrids could pose an unexpected hazard. Tests have shown that this is a valid concern, as vehicles operating in electric mode can be particularly hard to hear below 20 mph (30 km/h) for all types of road users and not only the visually impaired. At higher speeds, the sound created by tire friction and the air displaced by the vehicle start to make sufficient audible noise.
The Government of Japan, the U.S. Congress, and the European Parliament passed legislation to regulate the minimum level of sound for hybrids and plug-in electric vehicles when operating in electric mode, so that blind people and other pedestrians and cyclists can hear them coming and detect from which direction they are approaching. As of March 2013[update], most of the hybrids and plug-in electric cars available in the United States make warning noises using a speaker system.
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. In the same way, PHEVs do not emit greenhouse gases from the onboard source of power, but from the point of view of a well-to-wheel assessment, the extent of the benefit also depends on the fuel and technology used for electricity generation. From the perspective of a full life cycle analysis, the electricity used to recharge the batteries must be generated from renewable or clean sources such as wind, solar, hydroelectric, or nuclear power for PEVs to have almost none or zero well-to-wheel emissions. 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.
There has been much debate over the potential GHG emissions reductions that can be achieved with PHEV. A study by the Electric Power Research Institute reports that a 338 TW·h or 5.8% increase in power generation needed as a result of PHEV. In the same report the EPRI also states that CO2 emissions could increase by 430 million metric tons. The article concludes:
- "In summary, the addition of PHEVs as a significant transportation option adds approximately 6% to the total national electricity demand in 2030 compared to the base case with no PHEVs. Due to the charging profile that results in most of this additional demand occurring during off-peak hours (late night/early morning) there is an increase in the need for baseload generation. The addition of coal-fired generation to meet this need for more baseload generation does not result in any significant differences in annual emissions of SO2, NOx and Hg because of the caps on those pollutants. Therefore, any reductions in emissions of SO2, NOx or Hg from non-electric generating sources would result in a net national decline in these emissions. However, it does result in an appreciable increase in CO2 and PM emissions as this analysis has not assumed any limits on CO2 or PM emissions."
A study by the American Council for an Energy Efficient Economy (ACEEE) predicts that, on average, a typical American driver is expected to achieve about a 15% reduction in net CO
2 emissions compared to the driver of a regular hybrid, based on the 2005 distribution of power sources feeding the US electrical grid. The ACEEE study also predicts that in areas where more than 80% of grid-power comes from coal-burning power plants, local net CO
2 emissions will increase, while for PHEVs recharged in areas where the grid is fed by power sources with lower CO
2 emissions than the current average, net CO
2 emissions associated with PHEVs will decrease correspondingly.
A 2007 joint study by the Electric Power Research Institute (EPRI) and the Natural Resources Defense Council (NRDC) similarly found that the introduction of PHEVs into America’s consumer vehicle fleet could achieve significant greenhouse gas emission reductions. The EPRI-NRDC report estimates that, between 2010 and 2050, a shift toward PHEV use could reduce GHG emissions by 3.4 to 10.4 billion metric tons. The magnitude of these reductions would ultimately depend on the level of PHEV market penetration and the carbon intensity of the US electricity sector. In general, PHEVs can be viewed as an element in the "Pacala and Socolow wedges" approach which shows a way to stabilize CO
2 emissions using a portfolio of existing techniques, including efficient vehicles.
A 2008 study at Duke University suggests that for PHEV's to reduce greenhouse gas emissions more than hybrids a carbon pricing signal that encourages the development of low carbon power is needed. RAND also in 2008 studied the questions of a carbon tax, carbon cap and trade systems, increasing gasoline tax, and providing renewable energy subsidies under various economic conditions and vehicle type availabilities. RAND found that subsidies were able to provide a smoother transition to new energy sources, especially in the face of energy source price volatility, because subsidies can be structured according to relative costs between renewables and fossil fuel, while taxes and carbon trading schemes alone do not take relative prices of energy into account.
The Minnesota Pollution Control Agency found that if Minnesota's fleet of vehicles making lengthy trips were replaced by plug-in hybrids, CO
2 emissions per vehicle would likely decrease. However, unless more than 40% of the electricity used to charge the vehicles were to come from non-polluting sources, replacing the vehicles with non-plug-in hybrids would engender a larger decrease in CO
2 emissions. Plug-in hybrids use less fuel in all cases, and produce much less carbon dioxide in short commuter trips, which is how most vehicles are used. The difference is such that overall carbon emissions would decrease if all internal combustion vehicles were converted to plug-ins.
Argonne National Laboratory
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 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:
|PHEV well-to-wheels Petroleum energy use and greenhouse gas emissions
for an all-electric range between 10 and 40 miles (16 and 64 km) with different on-board fuels.(1)
(as a % relative to an internal combustion engine vehicle that uses fossil fuel gasoline)
and Ultra-low sulfur diesel
|E85 fuel from
corn and switchgrass
|Petroleum energy use reduction||
|GHG emissions reduction(2)||
|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.
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 recharged 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 National Laboratory
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. Each type of vehicle was assumed to run 20 miles (32 km) per day and the HEV was assumed to have a fuel economy of 40 miles per US gallon (5.9 L/100 km; 48 mpg-imp). The study considered the mix of power sources for 13 U.S. regions, generally a combination of coal, natural gas and nuclear energy, and to a lesser extend renewable energy. A 2010 study conducted at Argonne National Laboratory reached similar findings, concluding that PHEVs will reduce oil consumption but could produce very different greenhouse gas emissions for each region depending on the energy mix used to generate the electricity to recharge the plug-in hybrids. The following table summarizes the main results of the Oak Ridge National Laboratory study for the 2020 scenario:
|Comparison of carbon emissions and oil consumption by plug-in hybrids relative to hybrid electric vehicles (HEVs)
by U.S. regional power generation sources on 2020
relative to HEVs
relative to HEVs
|States included in the region(2)|
|Plug-in hybrid||All-electric mode||Plug-in hybrid||All-electric mode|
|-20.0%||-37.2%||-47.0%||-99.6%||Includes ID, MT, NV, OR, UT, SD, WA, and WY.|
|New England||Natural gas
|-11.4%||-17.4%||-44.3%||-93.5%||Includes CT, MA, ME, NH, RI, and VT.|
|Lower Midwest||Natural gas
|-11.0%||-16.4%||-46.9%||-99.4%||Includes AR, KS, LA, NM, OK, and TX.|
|-9.40%||-12.8%||-46.9%||-99.4%||Includes AZ, CO, NM, NV, and TX.|
|-1.2%||+6.1||-45.4%||-95.9%||Includes DC, DE, MD, ME, NJ, and PA.|
|Upper Midwest||Natural gas
|-0.8%||+7.2%||-46.7%||-99.0%||Includes IA, MN, MT, ND, NE, SD, and WI.|
|+2.4%||+14.4%||-46.7%||-98.9%||Includes AL, GA, LA, MS, NC, SC, and TN.|
|+7.8%||+27.0%||-46.6%||-98.7%||Includes IN, KY, MI, OH, VA, and WV.|
|+11.7%||+36.0%||-46.5%||-98.6%||Includes IA, IL, MI, MO, and WI.|
|Notes: (1) Regions as defined by the North American Electric Reliability Corporation. (2) Some states appear in more than one region because parts of them belong to different regions.|
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 CO
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 CO
2 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 CO
2 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 CO2/kW-hr in California to 986 g CO2/kW-hr in the Rockies, with a national average of 648 g CO2/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.
|Comparison of tailpipe and upstream CO
2 emissions(1) estimated by EPA
for the MY 2014 plug-in hybrids available in the U.S. market as of September 2014[update]
|Tailpipe + Total Upstream CO2|
|BMW i3 REx(3)||88||0.83||40||134||207||288|
|Ford C-Max Energi||51||0.45||129||219||269||326|
|Ford Fusion Energi||51||0.45||129||219||269||326|
|Honda Accord Plug-in Hybrid||57||0.33||130||196||225||257|
|Toyota Prius Plug-in Hybrid||58||0.29||133||195||221||249|
|Porsche Panamera S E-Hybrid||31||0.39||206||328||389||457|
|Average gasoline car||24.2||0||367||400||400||400|
|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
Production and sales
The BYD F3DM became the world's first mass-produced plug-in hybrid compact sedan as it went on sale in China to government agencies and corporations on December 15, 2008. The F3DM had an all-electric range of 100 kilometers (60 mi). Sales to the general public began in Shenzhen in March 2010 but because the F3DM nearly doubled the price of cars that run on conventional fuel, BYD Auto was counting on subsidies from the local government to make the plug-in attractive to personal buyers. The F3DM was sold for 149,800 yuan (about US$21,900), and during its first year in the market the F3DM only sold 48 vehicles. During 2010, 417 units were sold, and cumulative sales in China reached 3,284 units through October 2013. Production of the BYD F3DM was ended due to low sales, and it was replaced by the BYD Qin.
Deliveries of the Chevrolet Volt began in December 2010, initially only in selected U.S. markets, and became available nationwide in November 2011. The Volt has a United States Environmental Protection Agency rated all electric range of 35 mi (56 km). Deliveries of the 2012 Volt began in Canada in September 2011. The first deliveries of the Chevrolet Volt in Europe took place on November 30, 2011. The European version of the Volt, the Opel Ampera, was released to customers in Europe in February 2012. Deliveries of the right-hand drive Vauxhall Ampera in the UK began in May 2012. The Holden Volt was released in Australia in December 2012.
The Volt/Ampera family of vehicles was the world's best selling plug-in electric car in 2012 with 31,400 units sold, and ranked in the 432nd place among all models sold worldwide in 2012. The Opel/Vauxhall Ampera was Europe's top selling plug-in electric car in 2012 with 5,268 units representing a market share of 21.5% of the region's plug-in electric passenger car segment.
As of June 2014[update], with global sales of over 77,000 units, the Volt/Ampera family of vehicles is the world's second best selling plug-in electric car ever, after the Nissan Leaf, which has sold over 120,000 units worldwide. Volt sales are led by the United States with 63,167 units sold through June 2014. As of June 2014[update], a total of 9,189 Opel/Vauxhall Amperas have been sold since 2011, with the Netherlands as the leading market with 4,942 Amperas delivered through June 2014. As of June 2014[update], the Volt is the top selling plug-in electric car in the United States, and the Volt/Ampera family is the world's best selling plug-in hybrid.
As of May 2014[update], GM is developing the next generation model which is expected to be launched in 2015 as a 2016 model year. Due to the end of deliveries of Chevrolet vehicles to Europe by the end of 2015 to focus on its core European brands, Opel and Vauxhall, the American-made Chevrolet Volt will not be available in Europe beginning in 2016. In July 2014, Opel announced that due to the slowdown in sales, the Ampera will be discontinued after the launch of second generation Volt, and between 2014 and 2018, Opel plans to introduce in Europe a successor product in the electric vehicle segment.
Retail deliveries of the Fisker Karma began in November 2011. The Karma had an EPA rated all-electric range of 32 mi (51 km). Production was suspended in November 2012 due to financial difficulties, with about 2,450 Karmas built since 2011. As a result of flash floods caused by Hurricane Sandy in October 2012, 16 Karmas caught fire and another 330 units were lost when an entire shipment from Europe was flooded while being parked at Port Newark-Elizabeth Marine Terminal. Fisker Automotive filed for bankruptcy in November 2013, after the U.S. Department of Energy auctioned its debt and sold it to Hybrid Technology LLC. Around 2,100 units were sold in North America and Europe through December 2013, led by the United States with over 1,600 units sold. The Netherlands was the top selling European market for the Karma, with 188 units sold through December 2013.
The Toyota Prius Plug-in Hybrid was released in Japan in January 2012, and deliveries in the United States began in late February 2012. The Prius PHV total all-electric range in blended mode is 11 mi (18 km) as rated by EPA. During 2012, its first year in the market, global sales reached 27,181 units. As of September 2014[update], the Prius Plug-in Hybrid has sold 65,300 units worldwide, with the United States as the market leader with almost 37,000 units delivered, followed by Japan with about 19,100 units, and Europe with around 9,100 units. The European market is led by the Netherlands with 3,955 units registered as of August 2014[update].
The Ford C-Max Energi has an all-electric range of 20 mi (32 km) and was released in the U.S. by mid October 2012. The EPA rated the Energi combined city/highway fuel economy in all-electric mode at 88 MPG-e (2.7 L/100 km), 95 MPG-e (2.5 L/100 km) for city driving and 81 MPG-e (2.9 L/100 km) in highway. As of September 2014[update], a total of 16,014 units have been sold in the U.S. and 363 in Canada.
The Volvo V60 Plug-in Hybrid, the world's first diesel plug-in hybrid, has an all-electric range of up to 50 km (31 mi), and a fuel economy of 124 miles per gallon of gasoline equivalent (1.8 l/100 km), with carbon dioxide emissions averaging 49 g/km. Retail deliveries began in Sweden in late 2012 and the rest of Europe in early 2013. The diesel PHV is not expected to be available in the U.S. In September 2012, Volvo announced that the first 1,000 units were sold out before the model year 2013 vehicles were delivered to the dealerships. The carmaker ramped up production of the 2014 model year to 5,000 units for 2013. As of May 2014[update], over 11,000 units have been delivered in Europe. As of June 2014[update], sales are led by the Netherlands with 8,231 units, followed by Sweden with 931 units delivered. The V60 PHEV was the top selling plug-in hybrid in Europe accounting for the segment sales during the first eleven months of 2013.
The Honda Accord Plug-in Hybrid, with an all-electric range of 13 mi (21 km), was released in the U.S. in January 2013 and is available only in California and New York. A total of 526 units have been sold in the U.S. through December 2013. The Accord PHEV was introduced in Japan in June 2013 and it is available only for leasing, primarily to corporations and government agencies. As of December 2013[update], the Accord PHEV ranks as the third best selling plug-in hybrid in the Japanese market.
The Mitsubishi Outlander P-HEV was released in the Japanese market also in January 2013, becoming the world's first SUV plug-in hybrid in the market. The European version was released in Europe in October 2013. The introduction in the United States was delayed until 2015 due to problems in the initial production batch. The SUV has an all-electric range of 60 km (37 mi), and a fuel economy of 157 miles per gallon of gasoline equivalent (MPG-e). As of August 2014[update], over 35,000 units have been sold worldwide, led by the European market with over 19,000 units. Japan is the largest country market with 16,518 units sold, followed by the Netherlands with 14,195 units registered as of August 2014[update]. In the Netherlands the Outlander P-HEV ranked for two months in-a-row, November and December 2013, as the top selling new car in the country. As of August 2014[update], the Outlander P-HEV leads registrations of plug-in electric passenger vehicles in the Netherlands. During the first half of 2014 the Outlander P-HEV was the top selling plug-in electric vehicle in Europe with 9,038 units, and with total sales of 14,810 units sold globally, ranked as the world's second top selling plug-in electric car after the Nissan Leaf.
Deliveries of the Ford Fusion Energi began in the United States in February 2013. The Fusion Energi has an all-electric range of 20 mi (32 km) and an equivalent fuel economy EPA rating of 88 MPG-e (2.7 L/100 km). As of September 2014[update], a total of 15,412 units have been sold in the U.S. and 199 in Canada.
The limited edition McLaren P1 supercar was released in the UK in October 2013. The first P1 delivery in the U.S. occurred in May 2014. The P1 has an all-electric range of 6.2 mi (10.0 km) on the combined New European Driving Cycle. Production is limited to 375 units to maintain exclusivity. Pricing starts at GB£866,000 (€1,030,000 or US$1,350,000). With only 12 units manufactured by mid November 2013, the entire P1 production was sold out, with about 75% of the customers opting for some level of customization, raising the average sales price to GB£1 million (€1,2 million or US$1,6 million).
The Porsche Panamera S E-Hybrid was released in the U.S. in October 2013. The Panamera plug-in hybrid has an all-electric range of 32 km (20 mi) under the New European Driving Cycle (NEDC) test. As of August 2014[update], sales in the U.S. totaled 698 units, followed by the Netherlands with 220 units through June 2014. Global sales between January and August 2014 totaled over 1,500 units, presenting 9% of all Panamera models sold worldwide and 1.3% of all Porsche vehicles sold during this period.
Retail sales of the BYD Qin began in Costa Rica in November 2013, and sales in other Latin American countries are scheduled to begin in 2014. The start of retail sales in the Chinese market was rescheduled several times, and deliveries began in mid December 2013. The Qin ranked as the top selling plug-in electric car in China during the first quarter of 2014, and cumulative sales in the country totaled 6,599 units through July 2014.
The Cadillac ELR was released to retail customers in the U.S. and Canada in December 2013. The ELR is a limited production luxury coupé that shares the powertrain of the Chevrolet Volt and has an EPA-rated all-electric range of 37 miles (60 km). Cumulative sales in North America reached 926 units thourgh September 2014, with 891 units delivered in the U.S. and 35 units in Canada.
The Porsche 918 Spyder, with price starting at US$845,000 was released in Europe in May 2014. Deliveries in the United States began in June 2014. Production will be limited to 918 units to be sold as a 2014 model year. The supercar is capable of reaching 100 mph (160 km/h) in all-electric mode and has an EPA rated all-electric range of 12 mi (19 km). Retail deliveries of the BMW i8 began in Germany in June 2014. The i8 luxury sports car has an all-electric range of 37 km (23 mi) under the NEDC test. Pricing for the 2015 BMW i8 destined for the U.S. market starts at US$135,925 (€103,000 or GB£86,800) before any applicable government incentives. A total of 341 units have been sold through September 2014.
The Volkswagen XL1 was released to retail customers in Germany in June 2014. The XL1 has an all-electric range of 50 km (31 mi). The limited production XL1 is available only in Europe and pricing starts at €111,000 (~US$146,000). VW expects its diesel-powered XL1 to achieved 0.9 l/100 km (260 mpg-US), becoming the most fuel-efficient car in the world.
Sales of the Audi A3 Sportback e-tron began in Europe in August 2014, with the first 227 units were registered in Germany in August 2014. The A3 e-tron has an all-electric range of 50 km (31 mi) Retail sales in the U.S. are scheduled to begin in early 2015. The first 76 units of the Volkswagen Golf GTE were registered in Germany in August 2014. The Golf GTE has an all-electric range of 50 km (31 mi)
Before the launch of mass production plug-in hybrids, conversion kits and services were available in the United States to convert production model hybrid electric vehicles to plug-ins. The regular Toyota Prius has been commercially converted, using these aftermarket kits and tax incentives, to a plug-in hybrid by CalCars and a number of third-party companies. On a smaller scale, PHEVs have been sold as commercial passenger vans, utility trucks, general and school buses, motorcycles, scooters, and military vehicles. Hybrid Electric Vehicle Technologies, Inc converts diesel buses to plug-in hybrids, under contract for the Chicago Transit Authority. Fisher Coachworks is developing a plug-in hybrid, the Fisher GTB-40, which is expected to get about twice the mileage of a regular hybrid electric bus.
Sales and main markets
As of September 2014[update], global cumulative sales of plug-in hybrids totaled about 248,000 units, representing 41.3% of the 600,000 plug-in electric cars sold worldwide. Plug-in hybrid sales in 2012 were led by the United States with a 70% market share of global sales, followed by Japan with a 12%, the Netherlands with 8%, and Canada and China with 2% each. As of December 2013[update], the United States is the world's largest plug-in hybrid car market with 95,589 units sold, followed by Japan with 25,008 units, and the Netherlands with 24,512 plug-in hybrids registered through December 2013. The Netherlands is the country with highest plug-in hybrid market penetration, with 1.45 vehicles registered per 1,000 people. Most of the growth of the Dutch plug-in hybrid stock took place in 2013, with 20,164 units sold that year representing a rate of growth of 365% from 2012.
As of December 2013[update], the Netherlands, Sweden and the United States have the largest shares of plug-in hybrid sales as percentage of total plug-in electric passenger vehicle sales. Accounting for cumulative registrations between 2009 and 2013, plug-in hybrids represent 85.5% share of the Dutch plug-in passenger car market (28,673 units). Out of 2,651 plug-in electric cars sold in Sweden between 2011 and December 2013, plug-in hybrids have a 66.6% share. In the United States, out of over 167,600 plug-in electric cars sold through December 2013, plug-in hybrids represent 57.0% of total plug-in car sales since December 2010. In Japan, plug-in hybrids represent 33.7% of the 74,124 plug-in electric vehicles sold in the country since 2009 through December 2013.
In November 2013 the Netherlands became the first country where a plug-in hybrid topped the monthly ranking of new car sales. During November sales were led by the Mitsubishi Outlander P-HEV with 2,736 units, capturing a market share of 6.8% of new passenger cars sold that month. Again in December 2013 the Outlander P-HEV ranked as the top selling new car in the country with 4,976 units, representing a 12.6% market share of new car sales. These record sales allowed the Netherlands to become the second country, after Norway, where plug-in electric cars have topped the monthly ranking of new car sales.
The dominance of plug-in hybrids in the Netherlands is reflected by the fact that, since their inception up until August 2014, four out of the top five registered plug-in electric models are plug-in hybrids. As of 31 August 2014[update], Dutch plug-in passenger car registrations are led by the Mitsubishi Outlander P-HEV (14,195), followed by the Volvo V60 Plug-in Hybrid (8,758), Opel Ampera (4,965 units), and the Prius PHV (3,955). Ranking fifth is the Tesla Model S all-electric sedan (1,863), which recently passed the Chevrolet Volt plug-in hybrid (1,066). A total of 33,732 plug-in hybrids out of 39,838 light-duty plug-in electric vehicles were registered in the Netherlands as of August 2014[update], representing 84.7% of the country's highway legal plug-in electric drive stock.
The following table presents the top ranking countries according to its plug-in hybrid segment market share of total new car sales in 2013:
|Top 10 countries by plug-in hybrid market share
of new car sales in 2013
|Note: (1) Market share of highway-capable plug-in hybrids as percentage of total new car sales in the country in 2013.|
The following table presents sales of plug-in hybrid models since the introduction of the first modern production plug-in hybrid vehicle in December 2008, and summarizes sales in the top selling countries for each model through September 2014:
|Plug-in hybrid global sales and top markets by country or region
between December 2008 and September 2014
|Global sales||Top selling markets|
35 mi (56 km)
|Global sales through September 2014, including about 9,200 Amperas sold in Europe.|
|US||69,092||Chevrolet Volts through September 2014.|
|Netherlands||6,036||4,970 Amperas and 1,066 Volts through September 2014.|
|Canada||3,725||Chevrolet Volts through September 2014.|
|Germany||1,566||1,493 Amperas and 73 Volts through September 2014.|
|UK||857||767 Amperas and 90 Volts through March 2014.|
|Switzerland||622||397 Amperas and 225 Volts through September 2014.|
|France||424||367 Amperas and 57 Volts through June 2014.|
|Belgium||246||206 Amperas and 40 Volts through June 2014.|
|Norway||245||244 Amperas and 1 Volt through June 2014.|
|Austria||244||225 Amperas and 19 Volts through June 2014.|
|Australia||216||Holden Volts through June 2014.|
|Sweden||162||124 Amperas and 40 Volts through September 2014.|
|Toyota Prius PHV
11 mi (18 km)
|65,300||Global sales through September 2014.|
|US||36,680||Sales through September 2014.|
|Japan||19,100||Sales through September 2014.|
|Netherlands||3,978||Registrations through September 2014.|
|UK||1,089||Sales through March 2014.|
|Sweden||1,053||Sales through September 2014.|
|France||844||Sales through June 2014.|
|Norway||348||Sales through June 2014.|
|Canada||338||Sales through September 2014.|
|Finland||131||Sales through June 2014.|
|Spain||118||Sales through September 2014.|
|Mitsubishi Outlander P-HEV
60 km (37 mi)
|Sales through September 2014, of which, 17,235 units were sold in Europe.|
|Japan||16,518||Sales through August 2014.|
|Netherlands||14,567||Registrations through September 2014.|
|Sweden||1,835||Sales through September 2014.|
|Norway||818||Sales through June 2014.|
|UK||542||Sales through June 2014.|
|Germany||507||Sales through June 2014.|
|France||164||Sales through June 2014.|
|Belgium||89||Sales through June 2014.|
|Ford C-Max Energi
20 mi (32 km)
|16,377||Sales through September 2014.|
|US||16,014||Sales through September 2014.|
|Canada||363||Sales through September 2014.|
|Ford Fusion Energi
20 mi (32 km)
|15,611||Sales through September 2014.|
|US||15,412||Sales through September 2014.|
|Canada||199||Sales through September 2014.|
|Volvo V60 Plug-in Hybrid
50 km (31 mi)
|Sales through June 2014.|
|Netherlands||8,941||Registrations through September 2014.|
|Sweden||1,102||Sales through September 2014.|
|Germany||316||Sales through June 2014.|
|France||302||Sales through June 2014.|
|Belgium||256||Sales through June 2014.|
|Italy||150||Sales through June 2014.|
|Norway||120||Sales through June 2014.|
|Finland||96||Sales through June 2014.|
|Austria||82||Sales through June 2014.|
70 km (43 mi)
|9,615||China||9,615||Sales through September 2014.|
60 mi (97 km)
|3,292||Sales through December 2013.
Production ended in 2013. The F3DM was substituted by the BYD Qin.
|China||3,284||Sales through December 2013.|
|Spain||8||Sales through December 2012.|
32 mi (51 km)
|North America and Europe through December 2013.
Production was suspended in November 2012 due to financial difficulties.
|US||1,635||Sales through December 2013.|
|Netherlands||188||Registrations through December 2013.|
|Canada||98||Sales through May 2014.|
|Switzerland||79||Sales through June 2014.|
|Belgium||66||Sales through June 2014.|
|Germany||50||Sales through December 2013.|
|France||34||Sales through June 2014.|
|Sweden||21||Sales through December 2013.|
|Austria||13||Sales through December 2013.|
|Norway||5||Sales through December 2013.|
|Porsche Panamera S E-Hybrid
32 km (20 mi)
|Global sales through September 2014.|
|US||780||Sales through September 2014.|
|Netherlands||233||Registrations through September 2014.|
|Belgium||172||Sales through June 2014.|
|France||123||Sales through June 2014.|
|Germany||63||Sales through June 2014.|
|Spain||31||Sales through July 2014.|
|Sweden||9||Sales through September 2014.|
35 mi (56 km)
|926||Sales through September 2014.|
|US||891||Sales through September 2014.|
|Canada||35||Sales through September 2014.|
|Honda Accord Plug-in Hybrid
13 mi (21 km)
|835||US||835||Sales through September 2014.|
37 km (23 mi)
|341||Global through September 2014.|
|Germany||224||Registered through September 2014.|
|US||67||Sales through September 2014.|
|Switzerland||21||Sales through September 2014.|
|Netherlands||16||Sales through September 2014.|
|Spain||8||Sales through September 2014.|
|Total global plug-in hybrid sales
(Sales from December 2008 through September 2014)
|US||141,406||Sales up to September 2014 (includes Fisker Karma sales).|
|Japan||35,618||Sales through September 2014.|
|Netherlands||34,362||Registrations through September 2014.|
|China||12,899||Sales through September 2014.|
|UK||6,367||Registrations between January 2012 and September 2014.|
|Canada||4,758||Sales through September 2014.|
|Germany||4,438||Registrations through September 2014.|
|Sweden||4,299||Registered through September 2014.|
|France||1,891||Sales through June 2014.|
|Norway||1,582||Registrations through June 2014.|
|Belgium||Over 800||Sales through June 2014.|
|Switzerland||Over 700||Sales through June 2014.|
Plug-in vehicles ongoing demonstration trials include the Ford Escape Plug-in Hybrid, Volvo V70 Plug-in Hybrid, Suzuki Swift Plug-in, Audi A1 e-tron, Dodge Ram 1500 Plug-in Hybrid, and Volkswagen Golf Variant Twin Drive. PHEVs scheduled for market launch between in 2014 and 2015 are the Porsche Cayenne S E-Hybrid, Mercedes-Benz S 500 Plug-in Hybrid, Volvo XC90 Plug-in Hybrid and Volkswagen Passat GTE.
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 US$7,500, and several states have additional incentives. The UK offers a Plug-in Car Grant up to a maximum of GB£5,000 (US$7,600). As of April 2011, 15 of the 27 European Union member states provide tax incentives for electrically chargeable vehicles, which includes all Western European countries plus the Czech Republic and Romania. Also 17 countries levy carbon dioxide related taxes on passenger cars as a disincentive. The incentives consist of tax reductions and exemptions, as well as of bonus payments for buyers of all-electric and plug-in hybrid vehicles, hybrid vehicles, and some alternative fuel vehicles.
Other government support
- United States
Incentives for the development of PHEVs are included in the Energy Independence and Security Act of 2007. 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, and on March 19, 2009, he announced programs directing $2.4 billion to electric vehicle development.
The American Recovery and Reinvestment Act of 2009 modifies the tax credits, including a new one for plug-in electric drive conversion kits and for 2 or 3 wheel vehicles. The ultimate total included in the Act that is going to PHEVs is over $6 billion.
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." and of the world There are partnerships with Coulomb, Better Place and others are also advancing. The first charging stations went up in San Jose (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
GM's roadmap for plug-in ready communities includes: consumer incentives to make this early technology more affordable; public and workplace charging infrastructure; consumer-friendly electricity rates and renewable electricity options; government and corporate vehicle purchases; supportive permitting and codes for vehicle charging; and other incentives such as high-occupancy-vehicle (HOV) lanes access
- 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.
Organizations that support plug-in hybrids include the World Wide Fund for Nature, its International Director General James Leape remarked, "the cars of the future ... should, increasingly, be powered by electricity."
CalCars (with their PHEV news service and "What car makers are saying about PHEVs") is dedicated only to the PHEV and has proposed a Prepayment Plan, where buyers would pay $1,000 to reserve a plug-in car and the federal government would match each payment with $9,000, all of which would go to carmakers. CalCars is also promoting public funds for conversion of internal combustion engines to plug-in vehicles.
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), the San Francisco Bay Area Council, the Apollo Alliance, the Set America Free Coalition, the Silicon Valley Leadership Group, and the Plug-in Hybrid Electric School Bus Project,
FPL and Duke Energy has said that by 2020 all new purchases of fleet vehicles will be plug-in hybrid or all-electric.
NiMH battery patent encumbrance
Some battery formats and chemistries (nickel–metal hydride batteries) suitable for use in PHEVs are tightly patented and were not licensed for use by PHEV manufacturers, thereby slowed the development of electric cars and PHEVs before the 2008 Oil Crisis.
- Advanced Technology Vehicles Manufacturing Loan Program
- Alternative fuel vehicle
- Clean Energy Bank
- Electric transportation technology
- Electric TM4
- Fuel economy-maximizing behaviors
- Genset trailer
- Glossary of automotive design
- Government incentives for plug-in electric vehicles
- Green vehicle
- Inductive charging
- List of modern production plug-in electric vehicles
- Low-carbon economy
- Low-carbon fuel standard
- Plug In America
- Plug-in electric vehicle (PEV)
- Plug-in electric vehicle fire incidents
- Plug-in electric vehicles in Japan
- Plug-in electric vehicles in Norway
- Plug-in electric vehicles in the Netherlands
- Plug-in electric vehicles in the United Kingdom
- Plug-in electric vehicles in the United States
- Plug-in hybrids in California
- Plug-in hybrids in New York
- Plug-in Hybrid Electric Vehicle Research Center
- United States Council for Automotive Research
- Frank, A., et al.,. "What are Plug-In Hybrids?". Team Fate. University of California, Davis. Archived from the original on 2008-06-11. Retrieved August 7, 2007.
- Knipping, E. and Duvall, M. (June 2007) "Environmental Assessment of Plug-In Hybrid Electric Vehicles Volume 1: Nationwide Greenhouse Gas Emissions" Electric Power Research Institute and Natural Resources Defense Council. Retrieved July 21, 2007.
- A. Elgowainy, A. Burnham, M. Wang, J. Molburg, and A. Rousseau (February 2009). "Well-to-Wheels Energy Use and Greenhouse Gas Emissions Analysis of Plug-in Hybrid Electric Vehicles" (PDF). Center for Transportation Research, Argonne National Laboratory. Retrieved 2006-06-01. Report ANL/ESD/09-2
- Archer, David (2005). "Fate of fossil fuel CO
2 in geologic time" (PDF). Journal of Geophysical Research 110 (C9): C09S05.1–C09S05.6. Bibcode:2005JGRC..11009S05A. doi:10.1029/2004JC002625. Retrieved 2008-12-31.
- Sherry Boschert (2006). Plug-in Hybrids: The Cars that will Recharge America. New Society Publishers, Gabriola Island, Canada. ISBN 978-0-86571-571-4.
- Thomas Friedman (2008). Hot, Flat, and Crowded. Farrar, Straus and Giroux, New York. ISBN 978-0-374-16685-4. See reviewed by CalCars founder Felix Kramer (September 9, 2008) "T. Friedman's New Bestseller Hot, Flat & Crowded Touts Plug-Ins"
- "Electric generator dispatch depends on system demand and the relative cost of operation". U.S. E.I.A. "Today in Energy". U.S. Energy Information Administration. 2012-08-17. Retrieved 2014-10-04.
- Simpson, A. (2006) Cost-Benefit Analysis of Plug-in Hybrid Electric Vehicle Technology National Renewable Energy Laboratory conference report CP-540-40485 accessed January 7, 2009
- Eberle, Ulrich; von Helmolt, Rittmar (2010-05-14). "Sustainable transportation based on electric vehicle concepts: a brief overview". Royal Society of Chemistry. Retrieved 2010-06-08.
- Crippen, A. (December 15, 2008) "Warren Buffett's Electric Car Hits the Chinese Market, But Rollout Delayed For U.S. & Europe" CNBC. Retrieved December 2008.
- Balfour, F. (December 15, 2008) "China's First Plug-In Hybrid Car Rolls Out" Business Week. Retrieved December 2008.
- "BYD F3DM Plug-in Hybrid Goes On Sale in China". Green Car Congress. 2008-12-15. Retrieved 2009-02-28.
- "BYD Auto To Begin Sales of F3DM Plug-in to Individuals". Green Car Congress. 2010-03-23. Retrieved 2010-03-27.
- "BYD Auto to Offer F3DM Plug-in Hybrid to Chinese Individuals Starting Next Week". Edmunds.com. 2010-03-23. Retrieved 2010-03-27.
- "First Chevy Volts Reach Customers, Will Out-Deliver Nissan in December". plugincars.com. 2010-12-16. Retrieved 2010-12-17.
- Jeff Cobb (2014-10-22). "Global Plug-in Car Sales Now Over 600,000". HybridCars.com. Retrieved 2014-10-22. Cumulative global sales totaled 603,932 highway legal plug-in electric passenger cars and light utility vehicles through September 2014, consisting of 356,232 all-electric cars and utility vans and 247,700 plug-in hybrids. Accounts for sales only in the top ten world's markets.
- James, W. (September 2006) "Large Oil and GHG Reductions with Plug-in Hybrid Vehicles" Alternative Transport Energies Conference (Perth, Australia)
- IEEE-USA Board of Directors (June 15, 2007) "Plug-In Electric Hybrid Vehicles" Position Statement'.' Retrieved October 3, 2007.
- California Air Resources Board (July 2008) "California Certification and Installation Procedures for Off-Vehicle Charge Capable Conversion Systems for 2000 and Subsequent Model Year Hybrid Electric Vehicles". Retrieved January 8, 2009.
- "Making the Case for Grid-Connected Hybrids". EV World. 2001-09-23. Retrieved 2010-03-10.
- "What's In A Name?". EV World. 2005-04-07. Retrieved 2010-03-10.
- "The glossary". The Ergosphere. 2005-05-12. Retrieved 2010-03-10.
- "Chevy Volt: The Future is Electrifying". Chevrolet. Retrieved 2010-03-05.
- "History of Hybrid Vehicles". HybridCars.com. 2006-03-27. Retrieved 2011-10-25. See year 1898.
- "Lohner-Porsche Mixte Voiturette". Ultimate Car Page. 2007-11-19. Retrieved 2011-10-25.
- Popular Science (July, 1969) "Hybrid Car Ready in 1969" pp. 86–87. Retrieved December 31, 2008.
- Renault (March 10, 2003) "Kangoo reinvents the electric car" (PDF) press release. Retrieved January 8, 2009.
- Holinger, H. (2003) "Renault Electric Kangoo Can Do" EVWorld.com'.' Retrieved July 6, 2007.
- "How We Green-Tuned an '04 Prius into a PRIUS+ Plug-In Hybrid!". CalCars.com - The California Cars Initiative. Retrieved 2006-01-11.
- Thomas, Ken (July 19, 2006). "Toyota charging ahead with plans for plug-in hybrid". Chicago Sun-Times/Associated Press. Archived from the original on 2007-11-02.
- Lithium Ion Likely to Power Hybrids of the Future Hybrid Synergy View Newsletter, Toyota, April 2007. Retrieved August 7, 2007.
- Halvorson, Bengt. Li-ion Not Ready for Prius. BusinessWeek, June 18, 2007. Retrieved August 7, 2007.
- General Motors (November 29, 2006) "GM Announces Intention to Produce Plug-in Hybrid SUV". Retrieved January 8, 2009.
- GM Awards Lithium-Ion Battery Development Contracts. GM, January 4, 2007. Retrieved on 2007-08-07.
- General Motors (January 7, 2007) "Chevrolet Volt..." press release; video
- Green Car Congress (January 15, 2007) The Volt May be First, But E-Flex is the Key. Retrieved April 27, 2007.
- Toyota Motor Corporation (July 25, 2007) "Japan Certifies Toyota Plug-in Hybrid for Public-road Tests" JCN Newswire. Retrieved July 25, 2007.
- Terlep, S. (August 10, 2007) "GM races ahead with plug-in car" The Detroit News'.' Retrieved September 6, 2007.
- "Drive the Future with Fisker Automotive, A New Green American Premium Car Company" (PDF). September 5, 2007.
- Shirouzu, N., and Buckman, R. (January 14, 2008) "Electric-Car Firms Get Star Investors," Wall Street Journal
- Aptera Motors (2007) "FAQs" Aptera web site. Retrieved January 21, 2008.
- Jim Motavalli (2011-12-02). "Unable to Raise Financing, Aptera Shuts Down". The New York Times. Retrieved 2011-12-03.
- Edmunds (October 15, 2007) "Detroit Show Preview: BYD's New Plug-in Hybrid on Sale Next Year" Edmunds Inside Line. Retrieved October 26, 2007.
- "Ford Delivers First Escape Plug-In Hybrid To Southern California Edison". Media.Ford.Com. Retrieved 2010-11-27.
- "Ford Motor Company - Press Release - Ford Motor Company Delivers Flexible Fuel, Plug-In Vehicle to Department of Energy". Ford.com. Retrieved 2010-11-27.
- "Ford Escape Plug-in Hybrid". hybridCars.com. Retrieved 2010-04-21.
- "Ford Unveils 'Intelligent' System for Plug-In Hybrids To Communicate with the Electric Grid". Ford.com. Retrieved 2010-11-27.
- Plug-in car production race is on (Chicago Tribune)
- "News Releases". TOYOTA. 2008-01-14. Retrieved 2010-11-27.
- Ohnsman, A. (August 28, 2008) "Toyota Plans Electric Car, Earlier Plug-In Prius Test" Bloomberg. Retrieved December 2008.
- "Preliminary Summary of Air Resources Board Action (3/27/08) - Zero Emission Vehicle (ZEV) Program" 'arb.ca.gov
- California Air Resources Board (March 27, 2008) "ARB passes new ZEV amendment - Measure could produce 65,000 cleaner vehicles by 2012" (government agency release)
- Thompson (June 26, 2008) "VW starts testing electric cars, sees launching them by 2010" (Forbes) accessed December 2009
- 28 August 2008 (2008-08-28). "Mazda plans Volt rival". Autocar. Retrieved 2010-11-27.
- Associated Press (September 23, 2008) "Chrysler plans to sell electric car in 2010" New York Daily News
- Pakulski, Gary T. "Chrysler switching gears, to add electric car by 2010; 3 prototypes include Jeep Wrangler". toledoblade.com. Retrieved 2010-11-27.
- Chrysler unveils electric car that gets 150 miles a charge[dead link]
- Posted 9.24.08 at 10:01 am (2010-11-10). "Chrysler Reveals Alternative-Energy Prototypes - Popular Science". Popsci.com. Retrieved 2010-11-27.
- 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
- "Nissan will sell electric car for just over $25K". Yahoo Finance. 2010-03-30. Retrieved 2010-03-30.
- "TMC Introduces 'Prius Plug-in Hybrid' into Key Markets". Toyota News release. 2009-12-14. Retrieved 2010-04-09.
- "Toyota, EDF and Strasbourg Launch Large-Scale, 3-Year Plug-in Hybrid Demonstration Project". Green Car Congress. 2010-04-28. Retrieved 2010-04-28.
- "Toyota, EDF trial plug-in Prius in Britain". Reuters. 2010-01-11. Retrieved 2010-06-28.
- English, Andrew (2010-01-05). "Toyota Plug-In Prius review". London: The Telegraph. Retrieved 2010-04-10.
- Scott Deveau (2010-03-25). "Toyota tests Prius plug-in hybrid in Canada". Financial Post. Retrieved 2010-04-09.
- Brad Berman (2010-06-11). "Prius Plug-in Hybrid Arrives at Ultra-Green Portland State University". PlugInCars.com. Retrieved 2010-06-17.
- Vattenfall (September 2010). "Having a plug-in hybrid as your family car -what is it actually like?". PluginCars.com. Retrieved 2010-09-05. pp. 3-4
- "Volvo Reports Reactions from First Drivers of Volvo V70 Plug-in Hybrid". PluginCars.com. 2010-10-01. Retrieved 2010-10-05.
- John Voelcker (2009-06-02). "Volvo to Introduce Plug-In Diesel by 2012". Fox News. Retrieved 2009-06-04.
- "Lotus unveils range-extended electric city car concept in Paris". AutoblogGreen. 2010-10-02.
- Mark Gillies (2010-10-02). "Lotus City Car Concept - Auto Shows". Car and Driver. Retrieved 2010-10-04.
- Katie Fehrenbacher (2011-07-26). "PHOTOS: Kleiner's Ray Lane receives his Fisker Karma". earth2tech. Retrieved 2011-07-26.
- Stephen Munday (2011-09-30). "Prius Plug-In Hybrid On Sale January in Japan – Charging Stations at 5,500 Dealerships and Car Rental Locations". Integrity Exports. Retrieved 2011-09-30.
- John Voelcker (2012-04-03). "Plug-In Car Sales Soar In March, Led By Chevrolet Volt". Green Car Reports. Retrieved 2012-04-03.
- Toyota Motor Europe (2012-07-13). "Solid 13% Q2 sales increase for Toyota and Lexus vehicles in Europe". Toyota Media Press Release. Retrieved 2012-08-06.
- Jim Motavalli (2012-11-02). "Ford's Electric Cars: Starting Slow, and Waiting for the Market". PluginCars.com. Retrieved 2012-11-03.
- "2013 (Q1) Sweden: Best-Selling Electric Cars and Plugin Hybrid Models". BestSellingCars.com. 2013-04-12. Retrieved 2013-04-15.
- Pete Brissette (2013-01-21). "2014 Honda Accord Plug-in Hybrid Now Available in Calif. And New York". HybridCars.com. Retrieved 2013-01-21.
- Jay Cole (2013-01-24). "Mitsubishi Outlander PHEV On Sale In Japan Today, Extended Promotional Video Released". Inside EVs. Retrieved 2013-01-28.
- Jesse Sears (2013-02-27). "2013 Ford Fusion Energi: Fuel Economy, Pricing and Release Date". Cars Direc. Retrieved 2013-03-03.
- Jay Cole (2013-03-03). "February 2013 Plug-In Electric Vehicle Sales Report Card". Inside EVs. Retrieved 2013-03-04.
- Alysha Webb (2013-05-02). "China's BYD Opens Electric Bus Production Plant in California". PluginCars.com. Retrieved 2013-05-11.
- Beatriz Nuñez. "BYD Presenta su Auto Híbrido Qin" [BYD Presents its Hybrid Car Qin] (in Spanish). Puro Motor. Retrieved 2013-12-16.
- EV World (2013-12-04). "BYD Announces Sales Launch of Qin Electric Hybrid in Latin America". EV World. Retrieved 2013-12-16.
- John Voelcker (2013-12-09). "BYD Qin Plug-In Hybrid Now On Sale In Costa Rica". Green Car Reports. Retrieved 2013-12-16.
- Chinese Car News (2013-12-19). "BYD Launches Qin Plugin Hybrid – 189,800RMB to 209,800RMB". China Car Times. Retrieved 2013-12-19.
- Noah Joseph (2013-10-21). "McLaren P1 hits 62 mph in 2.8 seconds, 186 in 16.5". Autoblog.com. Retrieved 2013-10-21.
- Jay Cole (2014-01-03). "Cadillac ELR Arrives Early, Manages To Sell 6 Copies In December". InsideEvs.com. Retrieved 2014-01-03.
- Eric Loveday (2014-06-06). "World’s First BMW i8 Owners Take Delivery In Germany". InsideEVs.com. Retrieved 2014-06-07.
- Cristian Gnaticov (2014-06-03). "First Volkswagen XL1 gets delivered to German customer". Inautonews. Retrieved 2014-06-07.
- Mark Kane (2014-09-24). "Germany Plug-In Electric Vehicle Sales Report August 2014". InsideEVs.com. Retrieved 2014-09-29.
- Brandon Turkus (2014-08-07). "2016 Chevy Volt teased ahead of debut at Detroit Auto Show". Autoblog.com. Retrieved 2014-08-07. See more details in press release.
- Union of Concerned Scientists (2006) "Hybrids Under the Hood (part 2) -- Drivetrains" Hybridcenter.org. Retrieved May 31, 2007
- Schwoerer, Martin (2010). "REX Means Range". EV World. Retrieved 2014-10-11.
- Layton, J; Nice, K (2007). "How Hybrid Cars Work". HowStuffWorks.com. Retrieved 2007-06-19.
- BC Climate Exchange (2005) "Hybrid Basics" Hybrid Experience Report. Retrieved June 19, 2007.
- Toyota Motor Corporation (2006) "Series Parallel Hybrid System" Hybrid Synergy Drive. Retrieved June 19, 2007.
- "Toyota Prius Plug-in Hybrid Review". HybridCars.com. Retrieved 2012-03-18.
- "AC Propulsion's Reductive Charger"
- Green Car Congress (September 29, 2006) Plug-ins Progress. Retrieved April 27, 2007.
- Gonder, J. and Markel, T. (2007) "Energy Management Strategies for Plug-In Hybrid Electric Vehicles" (PDF) technical report NREL/CP-540-40970 presented at SAE World Congress, April 16–19, 2007, Detroit, Michigan
- Santini, et al. (September 27, 2006) Energy and Petroleum Consumption Attributes of Plug-in Hybrids (PDF). Retrieved April 29, 2007.
- Tony Markel/NREL: "Plug-in HEV Vehicle Design Options and Expectations" (PDF). Retrieved April 27, 2007.
- EAA-PHEV wiki: Mixed-mode. Retrieved April 29, 2007.
- Roim, J. and Frank, A. (April 2006) "Hybrid Vehicles Gain Traction" Scientific American pp. 72–9
- Bullis, K. (August 3, 2006) "Are Lithium-Ion Electric Cars Safe?" Technology Review (Cambridge, Mass.: MIT)
- Fleissner, C. (8/14/06) "Johnson Controls partnership wins new contract" Wisconsin Technology Network
- Altair Nanotechnologies Inc. (September 7, 2006) "Altair Nanotechnologies Details Long Life Features of Its Nano-Titanate Battery" Business Wire press release
- Voelcker, J. (January 2007) "Lithium Batteries for Hybrid Cars" IEEE Spectrum
- Toyota Motor Co (2004) "Hybrid Hype? Fact and Fiction Surrounding the New Technology" Toyota.com'.' Retrieved July 8, 2007.
- Woody, Todd. "PG&E's Battery Power Plans Could Jump Start Electric Car Market". (Blog). Green Wombat, 2007-06-12. Retrieved on 2007-08-19.
- Jansen, Matt. "Toyota laughs while Chevy Volt battery power is ripped in half". (Blog). tech.blorge, 2008-6-16. Retrieved on 2008-6-17.
- Électricité de France (September 5, 2007) "EDF et Toyota annoncent un partenariat technologique en Europe relatif aux véhicules hybrides rechargeables" press release. Retrieved October 10, 2007.
- Elektromotive, Ltd. (2007) "Elektromotive: The ultimate zero-emission transport system" company web site. Retrieved October 26, 2007.
- Reynolds, L. (October 11, 2007) "UK to install 250 new public charging stations by next spring". The Battery Vehicle Society. Retrieved October 26, 2007.
- Israel Is Set to Promote the Use of Electric Cars - New York Times
- Wald, M.L. (January 13, 2008)"Closing the Power Gap Between a Hybrid’s Supply and Demand,"New York Times Retrieved January 7, 2009.
- "Downing, Jim. "Plug-in hybrids promise more power, greater efficiency"". The Sacramento Bee. May 21, 2008. Archived from the original on May 2008.[dead link]
- "UltraBattery FAQs", 2010-05-06
- "Shiau, C.-S., C. Samaras, R. Hauffe and J.J. Michalek (2009) "Impact of battery weight and charging patterns on the economic and environmental benefits of plug-in hybrid vehicles,"" (PDF). Retrieved 2010-11-27.
- "Calcars.org". Calcars.org. Retrieved 2010-11-27.
- "Can Congress Hear From 6,692 Plug-In Supporters Today?". Calcars.org. Retrieved 2009-04-11.
- "Calcars.org" (PDF). Retrieved 2010-11-27.
- California Cars Initiative (2007) "Where Plug-In Hybrid Conversions (mostly Priuses) Are". Retrieved July 8, 2007.
- A123 Systems, Inc. (May 3, 2007) A123Systems Battery Co Acquires Hymotion Conversion Co Business Wire press release
- Electric Auto Association (2007) "Battery Pack Configurations" Plug in Hybrid Electric Vehicle website. Retrieved April 25, 2007.
- EDrive Systems, LLC (2006) "EDrive FAQ". Retrieved July 6, 2007.
- OEMtek: Prius Plug-in Hybrid Electric Vehicle (PHEV) - Home (Oemtek.com)
- Electric Auto Association "Plug in Hybrid Electric Vehicle" wiki (2005–present)
- "Conversion Interest". Eaa-Phev. Retrieved 2010-11-27.
- CalCars (2004) "How CalCars Green-Tuned an '04 Prius into a PRIUS+ Plug-In Hybrid!" calcars.org
- USA. "Luscious Garage PHEV conversions". Lusciousgarage.com. Retrieved 2010-11-27.
- "MIRA Introduces Plugless Plug-in Hybrid Conversion : Hybrid Car Chat Blog". Hybridcarchat.com. 2008-04-28. Retrieved 2010-11-27.
- "Concept: Through-the-Road PHEV Conversion Kit". Green Car Congress. 2008-07-20. Retrieved 2010-11-27.
- "Atlanta's Incentives Lift Electric Car Sales Tax Credit, Cheap Power Help Make Georgia Capitol a Hotbed for Battery Buggies". Wall Street Journal. 4 June 2014. Retrieved 13 October 2014. "Atlanta has been the top U.S. market for Nissan's Leaf car for eight of the past 10 months"
- "Gauging interest for plug-in hybrid and electric vehicles in select markets: Alternative powertrain survey highlights". EY. Retrieved 13 October 2014.
- "Summary of Travel Trends: 2009 National Household Travel Survey". U.S. Department of Transportation - Federal Highway Administration. p. 13. Retrieved 12 October 2014.
- "2011 Census Analysis, Distance Travelled to Work". Office for National Statistics (UK). 26 March 2014. Retrieved 12 October 2014.
- Austin, Michael. "4 Top Plug-in Hybrids, Tested". Popular Mechanics. Retrieved 12 October 2014.
- Edsall, Larry (2010). Endres, Chris, ed. Chevrolet Volt: Charging into the Future. Foreword by Bob Lutz (Hardcover ed.). Minneapolis, Minnesota: Motorbooks. pp. 91–16. ISBN 978-0-7603-3893-3.
- "GM to unveil Volt electric concept car". msnbc.com. Associated Press. 2007-01-07. Retrieved 2011-05-15.
- Eric Loveday (2014-10-03). "Chevy Volt Owners Pass 1 Billion Total Miles". InsideEVs.com. Retrieved 2014-10-13.
- U. S. Environmental Protection Agency (October 2014). "Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends: 1975 Through 2014". EPA. Retrieved 2014-10-11. See Table 7.2 - MY 2014 Alternative Fuel Vehicle Powertrain and Range; pp. 98; Table 7.3 for overall fuel economy (mpg-e), pp. 100; Table 7.4 for tailpipe CO2 emissions, pp. 102; and Table 7.5 for upstream CO2 Emission, pp. 105.
- "Electrified car sales stall as buyers back away from hybrids". Los Angeles Times. 4 September 2014. Retrieved 13 October 2014.
- International Humanities Center (September 24, 2008) "Senate OKs Plug-In Credits, Toyota Frets; Free Press Lyrical about Plug-Ins" California Cars Initiative
- Grove, Andy (July/August 2008) "Our Electric Future" The American (American.com)
- U. S. Environmental Protection Agency and U.S. Department of Energy (2011-05-27). "2011 Chevrolet Volt". Fueleconomy.gov. Retrieved 2011-05-31.
- "Volt receives EPA ratings and label: 93 mpg-e all-electric, 37 mpg gas-only, 60 mpg-e combined". Green Car Congress. 2010-11-24. Retrieved 2011-05-31.
- "EPA, DOT unveil the next generation of fuel economy labels". Green Car Congress. 2011-05-25. Retrieved 2011-05-31.
- EPA (May 2011). "Fact Sheet: New Fuel Economy and Environment Labels for a New Generation of Vehicles". U.S. Environmental Protection Agency. Retrieved 2011-05-31.EPA-420-F-11-017
- US Department of Energy (September 18, 2007) "Plug-In Hybrid Electric Vehicle Conversions" Alternative Fuels and Advanced Vehicles Data Center Retrieved November 8, 2007.
- Hamilton, Tyler. $3.83 to power hybrid plug-in for 6 days. June 9, 2008
- Johnson, James. Solar Energy into the PHEV Battery. May 2009
- Westneat, D. (February 22, 2009) Reality check on plug-in cars
- "RechargeIT.org". Google.org. Retrieved 2009-04-11.
- "Google.org". Google.org. Retrieved 2009-04-11.
- United States Environmental Protection Agency and U.S. Department of Energy (2014-09-10). "Model Year 2014 Fuel Economy Guide - Electric vehicles & Plug-in Hybrid Electric Vehicles (updated September 2014)". fueleconomy.gov. Retrieved 2014-09-12. pp. 33-36
- U. S. Environmental Protection Agency and U.S. Department of Energy (2012-11-30). "2012 Most and Least Efficient Vehicles". Fueleconomy.gov. Retrieved 2012-12-02. Click on the tab "Cars (excluding EVs)"
- U. S. Environmental Protection Agency and U.S. Department of Energy (2012-12-06). "Model Year 2013 Fuel Economy Guide". Fueleconomy.gov. Retrieved 2012-12-09. See "5-Year Fuel Cost Savings" page 1.
- "Why are the VOLT and LEAF EVs measured in Miles Per Gallon". Electric Vehicle News. 2009-08-15. Retrieved 2011-02-21.
- United States Environmental Protection Agency and U.S. Department of Energy (2014-07-04). "Compare Side-by-Side: 2014 BMW i3 BEV & 2014 BMW i3 REx". fueleconomy.gov. Retrieved 2014-07-27.
- John Voelcker (2013-10-23). "2014 BMW i3 Electric Car: Why California Set Range Requirements, Engine Limits". Green Car Reports. Retrieved 2014-01-19.
- John Voelcker (2014-05-02). "2014 BMW i3 Range-Extended Model Gets Full $2,500 CA Rebate For Electric Cars". Green Car Reports. Retrieved 2014-05-02.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2014-07-25). "Most Efficient EPA Certified Vehicles". fueleconomy.gov. Retrieved 2014-07-27. Current Model Year excludes all-electric vehicles.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2014-07-25). "Fueleconomy.gov's Top Ten EPA-Rated Fuel Sippers (1984 to present) - All Years". fueleconomy.gov. Retrieved 2014-07-26. Excludes all-electric vehicles. Click on the tab "EPA Rated - All Years. The 2013-2014 Chevrolet Volt has a combined fuel economy of 62 mpg-e.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2014-03-12). "2014 Honda Accord Plug-in Hybrid". Fueleconomy.gov. Retrieved 2014-04-05.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2012-11-30). "Compare Side-by-Side - 2013 Chevrolet Volt, 2012 Chevrolet Volt and 2011 Chevrolet Volt". Fueleconomy.gov. Retrieved 2012-12-09.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2012-11-30). "Compare Side-by-Side - 2013 Ford C-Max PHEV FWD, 2013 Chevrolet Volt, 2013 Toyota Prius Plug-in Hybrid, and 2012 Fisker Karma". Fueleconomy.gov. Retrieved 2012-12-01.
- Ford Motor Company (2012-11-08). "Ford C-MAX Energi: Most Range, More Efficiency and Affordability Than Any Plug-in Hybrid". Media Ford. Retrieved 2012-12-02. EPA ratings in MPG-e for combine, city and highway cycles.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2014-06-12). "Compare Side-by-Side - 2013/14 Ford C-Max Plug-in Hybrid and 2013/14 Ford Fusion Plug-in Hybrid". Fueleconomy.gov. Retrieved 2014-06-12.
- Jeff Cobb (2014-06-12). "Ford Downgrades Hybrid Model MPG Ratings". HybridCars.com. Retrieved 2014-06-12.
- U.S. Environmental Protection Agency and U.S. Department of Energy (2014-03-07). "2014 Cadillac ELR". Fueleconomy.gov. Retrieved 2014-03-10.
- U.S. Environmental Protection Agency and U.S. Department of Energy (2014-08-21). "2014 BMW i8". Fueleconomy.gov. Retrieved 2014-08-22.
- U.S. Environmental Protection Agency and U.S. Department of Energy (2014-05-30). "2015 Porsche 918 Spyder". Fueleconomy.gov. Retrieved 2014-06-01.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2014-04-02). "Compare Side-by-Side - Porsche Panamera S E-Hybrid". Fueleconomy.gov. Retrieved 2014-04-05. Gasoline price was adjusted to $3.81 per gallon for comparison purposes to reflect the same price used for the other cars shown in this table.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2014-09-12). "Compare Side-by-Side - 2014 McLaren Automotive P1". Fueleconomy.gov. Retrieved 2014-09-12. Gasoline price was adjusted to $3.81 per gallon for comparison purposes to reflect the same price used for the other plug-in hybrid cars shown in this table.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2012-11-30). "Compare Side-by-Side - 2013 Toyota Prius". Fueleconomy.gov. Retrieved 2012-12-02.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2012-11-30). "Comparison Side-by-Side - 2013 Toyota Prius c and 2013 Toyota Prius". Fueleconomy.gov. Retrieved 2012-12-09.
- U. S. Environmental Protection Agency and U.S. Department of Energy (2012-11-30). "Comparison Side-by-Side - 2013 Chrysler 200, 2013 Ford Taurus FWD, 2013 Toyota Venza, and 2013 Hyundai Santa Fe Sport 2WD". Fueleconomy.gov. Retrieved 2012-12-09.
- Xing Wu, Jing Dong, Zhenhong Lin (2014-03-11). "Study finds energy savings of PHEVs relative to HEVs dependent on charging coverage and daily VMT". Green Car Congress. Retrieved 2014-03-23. 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
- Michael Graham Richard (2009-10-14). "Could Range Anxiety Sabotage the Promise of Electric Cars?". Discovery's Planet Green. Retrieved 2013-08-11.
- "Study Shows Range Anxiety is Significant". Gm-volt.com. Retrieved 2010-11-27.
-  Big Day for GM Chevy Volt and Plug-In Cars
- Viknesh Vijayenthiran (2010-07-20). "First Major Outing For BMW Megacity Vehicle At 2012 London Olympic Games". Motor Authority. Retrieved 2010-07-23.
- Benjamin Preston (2013-07-29). "BMW Unveils i3 Electric Car". The New York Times. Retrieved 2013-07-29.
- Michaël Torregrossa (2013-07-30). "Voiture électrique - La BMW i3 officiellement révélée" [Electric car - the BMW i3 officially revealed] (in French). Association pour l'Avenir du Véhicule Electrique Méditerranéen (AVEM). Retrieved 2013-07-31.
- Eric Loveday (2013-07-22). "Official: BMW i3 Range Extender Option Adds 4,490 Euros ($5,919 US) to Price Tag in Netherlands". InsideEVs.com. Retrieved 2013-07-29.
- "$3.83 to power hybrid plug-in for 6 days". Wheels.ca. Retrieved 2010-11-27.
- Oyobe, H. et al. (2005) "Development of Ultra Low-Cost, High-Capacity Power Generation System Using Drive Motor and Inverter for Hybrid Vehicle" Fortieth Industry Applications Conference Annual Meeting.. Retrieved April 23, 2007.
- Green Car Congress (September 26, 2005) "Toyota Dream House with Plug-In Prius". Retrieved April 23, 2007.
- Green Car Congress (November 18, 2005) "Plugging the Plug-In Hybrid". Retrieved April 20, 2007.
- Green Car Congress (September 27, 2006) The Plug-In and BEV Adoption Wild Card: Vehicle-to-Grid. Retrieved April 28, 2007.
- Green Car Congress (April 9, 2007) "PG&E Demonstrates Vehicle-to-Grid Technology". Retrieved April 20, 2007.
- News.com (April 9, 2007) "PG&E sees plug-in hybrids as potential profit centers"
- Liotsakis, P. (2007) "Cars, Power Plants and 'Cash Back Hybrids'" LiveNeutral (Presidio School of Management and Chicago Climate Exchange) accessed July 12, 2007.
- National Research Council (2010). "Transitions to Alternative Transportation Technologies--Plug-in Hybrid Electric Vehicles". The National Academies Press. Retrieved 2010-03-03.
- Jad Mouawad and Kate Galbraith (2009-12-14). "Study Says Big Impact of the Plug-In Hybrid Will Be Decades Away". New York Times. Retrieved 2010-03-04.
- National Research Council (2009-12-14). "Plug-In Hybrid Vehicle Costs Likely to Remain High, Benefits Modest for Decades". National Academy of Sciences. Retrieved 2010-03-04.
- Hiroko Tabuchi (2009-12-14). "Toyota to Sell Plug-In Hybrid in 2011". New York Times. Retrieved 2010-02-03.
- Siddiq Khan and Martin Kushler (June 2013). "Plug-in Electric Vehicles: Challenges and Opportunities". American Council for an Energy-Efficient Economy. Retrieved 2013-07-09. ACEEE Report Number T133.
- Henry Lee and Grant Lovellette (July 2011). "Will Electric Cars Transform the U.S. Vehicle Market?". Belfer Center for Science and International Affairs, Kennedy School of Government. Retrieved 2011-08-07.
- Henry Lee and Grant Lovellette (July 2011). "WillElectricCars Transform the U.S. Vehicle Market?". Belfer Center for Science and International Affairs, Kennedy School of Government. Retrieved 2011-08-07. Discussion Paper #2011-08.
- "Lithium Phosphate Battery - Energy Storage Systems". Valence.com. Retrieved 2010-11-27.
- OEMtek: Prius Plug-in Hybrid Electric Vehicle (PHEV)
- A123 Systems, Inc. (2008) "Convert your hybrid electric vehicle into a plug-in hybrid electric vehicle" Hymotion.com
- Alan L. Madian et al (2009). "Chapter 5: The Impact of Plug-in Hybrids on U.S. Oil Use and Greenhouse Gas Emissions". Retrieved 2010-03-07. in "Plug-in Electric Vehicles: What Role for Washington?" pp.96, The Brookings Institution, ISBN 978-0-8157-0305-1
- Kevin Morrow et al (November 2008). "Plug-in Hybrid Electric Vehicle Charging Infrastructure Review. Final Report". U.S. Department of Energy Vehicle Technologies Program. Retrieved 2010-03-07.
- Todd Woody and Clifford Krauss (2010-02-14). "Cities Prepare for Life With the Electric Car". New York Times. Retrieved 2010-03-07.
- Huang, Jing; Gupta, V.; Huang, Yih-Fang (2012-06-27). "Scheduling algorithms for PHEV charging in shared parking lots". American Control Conference (ACC): 276–281.
- "Moving Forward in Raleigh PGR Plan". Project Get Ready. Retrieved 2010-03-07.
- RechargeIT Driving Experiment - RechargeIT is a program sponsored by Google.org, a non-profit created by Google.
- 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.
- Clayton, M. (September 25, 2006) "A reality check on plug-in hybrids" The Christian Science Monitor
- Kanellos, M. (April 28, 2006) "Plug in your hybrid, pollute less?" cNet News.com
- National Academy of Science (Oct. 19, 2009) "Hidden Costs of Energy: Unpriced Consequences of Energy Production and Use"
- Technology Options 2003. (2003). US Climate Change Technology Program.
- "Question: Where can I find data on electricity transmission and distribution losses?". Frequently Asked Questions – Electricity. U.S. Energy Information Administration. 2009-11-19. Retrieved 2010-03-28.
- Pacific Gas and Electric (2008) "Understanding Baseline Quantities"
- Pacific Gas and Electric (2008) Explanation of Residential Bill
- Pacific Gas and Electric Tariff Schedule E-9, "Experimental Residential Time-of-Use Service for Low Emission Vehicle Customers" (from PG&E Tariff Book)
- Bullis, K. (December 21, 2006) "How Plug-in Hybrids Will Save the Grid" Technology Review
- Lemoine, D.M. et al.; Kammen, D M; Farrell, A E (2008). "An innovation and policy agenda for commercially competitive plug-in hybrid electric vehicles". Environmental Research Letters 3 (1): 14003. Bibcode:2008ERL.....3a4003L. doi:10.1088/1748-9326/3/1/014003.
- "Página sobre el Salar (Spanish)". Evaporiticosbolivia.org. Retrieved 2010-11-27.
- Simon Romero (2009-02-02). "In Bolivia, Untapped Bounty Meets Nationalism". New York Times. Retrieved 2010-02-28.
- Irving Mintzer (2009). "Chapter 6: Look Before You Leap: Exploring the Implications of Advanced Vehicles for Import Dependence and Passerger Safety". Retrieved 2010-03-07. in "Plug-in Electric Vehicles: What Role for Washington?", The Brookings Institution, ISBN 978-0-8157-0305-1
- Clifford Krauss (2009-03-09). "The Lithium Chase". New York Times. Retrieved 2010-03-10.
- Jerry Garret (2010-04-15). "A Case for and Against Electric Cars". New York Times. Retrieved 2010-04-17.
- "USGS Mineral Commodities Summaries 2009". U. S. Geological Survey. January 2009. Retrieved 2010-03-07. See page 95.
- Hammond, C. R. (2000). The Elements, in Handbook of Chemistry and Physics 81st edition. CRC press. ISBN 0-8493-0481-4.
- Nuckols, Ben (3 March 2007). "Blind people: Hybrid cars pose hazard". USA Today. Retrieved 2009-05-08.
- "Electric cars and noise: The sound of silence". Economist. 7 May 2009. Retrieved 2009-05-08.
- David Shepardson (2011-01-04). "Obama signs law to require 'quiet' cars to get noisier". The Detroit News. Retrieved 2011-01-05.[dead link]
- "TMC to Sell Approaching Vehicle Audible System for 'Prius'". Toyota Motor Company News Release. 2010-08-24. Retrieved 2010-08-25.
- European Parliament (2013-02-06). "European Parliament backs law to tone down harmful traffic noise". European Parliament News. Retrieved 2013-03-17.
- Gabe Nelson (2013-03-01). "Louder EVs may turn off drivers, automakers say". Automotive News. Retrieved 2013-03-21.
- Sperling, Daniel and Deborah Gordon (2009). Two billion cars: driving toward sustainability. Oxford University Press, New York. pp. 22 to 26 and 114–139. ISBN 978-0-19-537664-7.
- David B. Sandalow, ed. (2009). Plug-In Electric Vehicles: What Role for Washington? (1st. ed.). The Brookings Institution. ISBN 978-0-8157-0305-1. pages=2–5
- "Environmental Assessment of Plug-In Hybrid Electric Vehicles, Volume 2: United States Air Quality Analysis Based on AEO-2006 Assumptions for 2030" (PDF). Archived from the original on 2007-11-28. Retrieved 2010-11-27.
- Kliesch, J. and Langer, T. (September 2006) "Plug-In Hybrids: an Environmental and Economic Performance Outlook" American Council for an Energy-Efficient Economy
- Williams, E.(November 2008) "Plug-in and regular hybrids: A national and regional comparison of costs and CO2 emissions." Nicholas School of the Environment at Duke University
- Toman, M. et al. (2008) "Impacts on U.S. Energy Expenditures and Greenhouse-Gas Emissions of Increasing Renewable-Energy Use" RAND Environment, Energy, and Economic Development program (RAND Tech Rep. No. 384-1)
- Minnesota Pollution Control Agency (March 2007) "Air Emissions Impact of Plud-In Hybrid Vehicles in Minnesota's Passenger Fleet"
- Timothy Searchinger et al. (2008-02-29). "Use of U.S. Croplands for Biofuels Increases Greenhouse Gases Through Emissions from Land-Use Change". Science 319 (5867): 1238–1240. Bibcode:2008Sci...319.1238S. doi:10.1126/science.1151861. PMID 18258860. Retrieved 2008-05-09. Originally published online in Science Express on 7 February 2008. See Letters to Science by Wang and Haq. There are critics to these findings for assuming a worst-case scenario.
- Fargione et al.; Hill, J; Tilman, D; Polasky, S; Hawthorne, P (2008-02-29). "Land Clearing and the Biofuel Carbon Debt". Science 319 (5867): 1235–1238. Bibcode:2008Sci...319.1235F. doi:10.1126/science.1152747. PMID 18258862. Retrieved 2008-08-06. Originally published online in Science Express on 7 February 2008. There are rebuttals to these findings for assuming a worst-case scenario
- Stanton W. Hadley and Alexandra Tsvetkova (January 2008). "Potential Impacts of Plug-in Hybrid Electric Vehicles on Regional Power Generation". Oak Ridge National Laboratory. Retrieved 2010-08-23. Report ORNL/TM-2007/150
- Michael Moyer (July 2010). "The Dirty Truth about Plug-in Hybrids". Scientific American. Retrieved 2010-08-23.
- "Different energy mixes will fuel plug-in hybrid cars". Argonne National Laboratory. 2010-08-17. Retrieved 2010-08-23.
- Amgad Elgowainy, J. Han, L. Poch, M. Wang, A. Vyas, M. Mahalik, and A. Rousseau (June 2010). "Well-to-Wheels Analysis of Energy Use and Greenhouse Gas Emissions of Plug-in Hybrid Electric Vehicles". Argonne National Laboratory. Retrieved 2010-08-23.
- "The Dirty Truth about Plug-in Hybrids, Made Interactive". Scientific American. July 2010. Retrieved 2010-08-22. Click on the map to see the results for each region.
- Mike Millikin (2014-10-11). "EPA Trends on EVs and PHEVs; beginning of a "measurable and meaningful impact" on new vehicle fuel economy and emissions". Green Car Congress. Retrieved 2014-10-11.
- BYD to Launch Electric Car Sales in China Next Month -EVWorld
- "BYD Plans to Start European Car Sales Next Year (Update 2)". Bloomberg Businessweek Week. 2010-03-08. Retrieved 2013-01-29. 48 units sold in 2009.
- "BYD Delivered Only 33 Units of e6, 417 F3DM in 2010". ChinaAutoWeb. 2011-02-23. 417 units were delivered in 2010.
- Mat Gasnier (2013-01-14). "China Full Year 2012: Ford Focus triumphs". Best Selling Car Blog. Retrieved 2013-01-29. A total of 613 units were sold during 2011 and 1,201 units in 2012.
- Colum Murphy and Rose Yu (2013-11-27). "China Hopes Cities Can Help Boost Electric Car Sales". The Wall Street Journal (China Real Time). Retrieved 2013-11-28. A total of 1,096 F3DMs were sold between January and October 2013.
- Eric Loveday (2011-06-10). "2012 Chevrolet Volt priced at $39,995*, now available to order nationwide". AutoblogGreen. Retrieved 2011-06-10.
- Peter Valdes-Dapena (2010-07-01). "Chevy Volt bound for Texas, New York area". CNN Money. Retrieved 2010-07-01.
- "Chevrolet begins taking orders in all 50 US states for 2012 Volt; $1K drop in starting price". Green Car Congress. 2011-06-10. Retrieved 2011-06-10.
- The Canadian Press (2011-09-01). "Chevy brings electric Volt to Canada". CBC News. Retrieved 2011-09-22.
- "Chevrolet Canada begins taking orders for the Volt starting at C$41,545; Volts a showroom draw in US". Green Car Congress. 2011-05-04. Retrieved 2011-05-05.
- William Diem (2011-12-01). "U.S. Embassy in France Buys Four Chevy Volts". The New York Times. Retrieved 2011-12-12.
- David Jolley (2011-12-12). "Opel delays Ampera deliveries to customers on battery worries". Automotive News Europe. Retrieved 2011-12-12.
- Opel Media (2012-02-21). "Opel Ampera: First Customers Take Delivery". Opel Europe. Retrieved 2012-03-01.
- Tim Pollard (2010-12-13). "Chevrolet Volt for European sale in November 2011". Car MagazineOnline. Retrieved 2010-05-20.
- David Ellery (2012-12-13). "Ambassador gets a charge out of new Volt". The Canberra Times. Retrieved 2012-12-16.
- Mat Gasnier and Austin Rutherford (2013-03-20). "World Full Year 2012: Discover the Top 1000 best-selling models!". Best Selling Cars Blog. Retrieved 2013-03-28.
- Eric Loveday (2013-03-28). "2012 Top 1,000 Global Sales List: Chevy Volt Ranks 432, Nissan LEAF 468, Renault Twizy 626, Mitsubishi i-MiEV 645, Tesla Model S 730". InsideEVs.com. Retrieved 2013-03-28.
- Mat Gasnier (2013-02-10). "Europe Full Year 2012: Now with Top 350 models & Top 60 brands". Best Selling Cars Blog. Retrieved 2013-11-26. Ampera sales in Europe totaled 5,268 units in 2012 and 304 in 2011.
- Christopher Bruce (2012-12-12). "Europe's Best Selling Electric Car Is the Opel/Vauxhall Ampera". Autovia. Retrieved 2013-02-13.
- Cobb, Jeff (2014-07-09). "Plug-In Car Sales Cross Global Half-Million Mark". HybridCars.com. Retrieved 2014-08-03.
- Antony Ingram (2014-07-02). "Plug-In Electric Car Sales In June: Leaf's Best-Ever June, Volt Up On May (FINAL UPDATE)". Green Car Reports. Retrieved 2014-07-23.
- Mike Colias (2014-07-21). "Opel will discontinue weak-selling Ampera, sources say". Automotive News Europe. Retrieved 2014-07-23. Ampera sales in Europe totaled 3,184 units in 2013.
- Mat Gasnier (2014-08-05). "Europe June 2014: Discover the Top 340 models and Top 55 brands". Best Selling Cars Blog. Retrieved 2014-08-07. Ampera sales in Europe totaled 433 units during the first half of 2014.
- Rijksdienst voor Ondernemend Nederland (RVO) (July 2014). "Cijfers elektrisch vervoer - Aantal geregistreerde elektrische voertuigen in Nederland - Top 5 geregistreerde modellen plug-in hybride elektrische voertuigen (30-06-2014) - Top 5 geregistreerde modellen volledig elektrische voertuigen (30-06-2014)" [Figures electric transport - Number of registered electric vehicles in Netherlands, Top 5 registered plug-in electric hybrid vehicle models (06-30-2014) and Top 5 registered all-electric vehicle models (06-30-2014)] (in Dutch). RVO (Dutch National Office for Enterprising). Retrieved 2014-09-17. See under the heading "30-06-2014" for total registrations at the end of June 2014.
- Jose Pontes (2013-06-15). "World All Time Top 10 (Updated to 30 April 2013)". EV Sales. Retrieved 2013-06-29.
- Jose Pontes (2013-12-28). "World Top 10 November 2013". EV Sales. Retrieved 2013-12-29.
- Voelcker, John (2014-03-18). "2016 Chevrolet Volt To Launch Next Year: What We Know So Far". Green Car Reports. Retrieved 2014-03-17.
- Tim Devaney (2013-12-05). "GM ending Chevy sales in Europe to focus on Opel and Vauxhall". The Washington Times. Retrieved 2014-07-23.
- Eric Loveday (2013-12-05). "Beginning in 2016, Chevy Volt Will No Longer be Available in Europe". InsideEVs.com. Retrieved 2014-07-23.
- Staff (2014-07-23). "Opel plans 'electric' successor to Ampera plug-in hybrid". Automotive News. Retrieved 2014-07-23.
- Fisker Automotive (press release) (2011-10-19). "Fisker Karma gets EPA certified: 52 mpge, 32-mile electric range then 20 mpg". Autoblog Green. Retrieved 2011-10-19. See details in Press Release.
- Bradley Berman (2013-03-13). "Henrik Fisker Resigns From Fisker Automotive". The New York Times. Retrieved 2013-06-18.
- Deepa Seetharaman and Paul Lienert (2013-06-17). "Special Report: Bad Karma: How Fisker burned through $1.4 billion on a 'green' car". Reuters. Retrieved 2013-06-18.
- Josie Garthwaite (2012-11-02). "Mystery at Port Newark: Why Did 17 Plug-In Cars Burn?". The New York Times. Retrieved 2012-11-03.
- Pete Brissette (2012-11-07). "Hurricane-Induced Fires; Reports 330 More Destroyed". HybridCars.com. Retrieved 2012-11-18.
- Angela Greiling Keane (2013-11-23). "Fisker Selling Assets to Li Group at $139 Million Loss to U.S.". Bloomberg (The Washington Post). Retrieved 2013-11-23.
- Cole, Jay (2014-01-03). "December 2013 Plug-In Electric Vehicle Sales Report Card". InsideEvs.com. Retrieved 2014-01-03.
- Jose Pontes (2013-01-06). "USA Full Year 2012". EV Sales. Retrieved 2013-07-19.
- Jose Pontes (2013-07-19). "USA June 2013". EV Sales. Retrieved 2013-07-20.
- RAI (January 2014). "Verkoopstatistieken - nieuwverkoop personenautos" [Sales Statistics - New passenger car sales] (in Dutch). RAI Vereniging. Retrieved 2014-01-25. Download pdf file for detailed sales in 2011 ("Download nieuwverkoop personenautos 201112"), in 2012 ("Download nieuwverkoop personenautos 201212"), 2013 ("Download nieuwverkoop personenautos 201312").
- Toyota News Release (2012-02-28). "Prius Plug-In eligibile for a $1,500 California consumer incentive plus $2,500 Federal tax credit". Green Car Congress. Retrieved 2012-02-29.
- Siddharth Philip (2013-03-12). "GM’s Chevy Volt Outsold Nissan Leaf Last Year, BNEF Says". Bloomberg L.P. Retrieved 2013-03-30.
- "Toyota Is Global Hybrid Leader With Sales Of 7 Million" (Press release). Torrance, California: PR Newswire. 2014-10-13. Retrieved 2014-10-15.
- Rijksdienst voor Ondernemend Nederland (RVO) (September 2014). "Cijfers elektrisch vervoer - Aantal geregistreerde elektrische voertuigen in Nederland - Top 5 geregistreerde modellen plug-in hybride elektrische voertuigen (31-08-2014) - Top 5 geregistreerde modellen volledig elektrische voertuigen (31-08-2014)" [Figures electric transport - Number of registered electric vehicles in Netherlands, Top 5 registered plug-in electric hybrid vehicle models (08-31-2014) and Top 5 registered all-electric vehicle models (08-31-2014)] (in Dutch). RVO (Dutch National Office for Enterprising). Retrieved 2014-09-17. See under the heading "31-08-2014" for total registrations figures at the end of August 2014.
- Jeff Cobb (2013-01-08). "December 2012 Dashboard". HybridCars.com and Baum & Associates. Retrieved 2013-01-14. See the section: U.S. Plug-in Electric sales for December 2012.
- Jeff Cobb (2014-10-02). "September 2014 Dashboard". HybridCars.com and Baum & Associates. Retrieved 2014-10-03.
- Klippenstein, Matthew (2014-10-06). "Plug-in Electric Car Sales In Canada, September 2014". Green Car Reports. Retrieved 2014-10-11. Estimated Ford Energi models.
- Autoblog staff (2011-03-11). "Geneva 2011: Volvo V60 Plug-In Hybrid plugs in at the PalExpo". Autoblog Green. Retrieved 2012-09-30.
- Sebastian Blanco (2012-09-28). "First 1,000 Volvo V60 Plug-in Hybrids already sold out". Autoblog Green. Retrieved 2012-09-30.
- Paul McVeigh (2011-01-27). "Geneva auto show: Volvo prepares to unveil V60 plug-in hybrid". Autoweek. Retrieved 2012-09-30.
- Geraldine Ashton Green (2012-12-03). "Volvo increase production of new V60 Plug-in Hybrid". Motoring UK. Retrieved 2012-12-09.
- Jim Motavalli (2014-06-30). "Confirmed: Volvo To Offer Plug-In Hybrid Option on All Models". PluginCars.com. Retrieved 2014-09-03. Volvo sold 7,739 V60 plug-in hybrids in 2013 and another 3,230 through May 2014. A total of 42 units were delivered in Sweden in 2012.
- "2012 (Full Year) Sweden: Best-Selling Electric Cars & Plug-In Hybrid Models". BestSellingCars.com. 2013-04-02. Retrieved 2013-07-05. 88 Amperas and 33 Volts were sold in 2012. A total of 42 Volvo V60 PHEVs were delivered in 2012.
- Bil Sweden (2014-01-02). "Nyregistreringar december 2013 prel" [New registrations in December 2013 prel] (in Swedish). Bil Sweden. Retrieved 2014-01-03. Download file "Nyregistreringar December 2013 prel.pdf" see table "NYREGISTRERADE SUPERMILJÖBILAR DECEMBER 2013" with summary of PEV sales by model for 2013 and 2012.
- Bil Sweden (2014-07-01). "Nyregistreringar juni 2014" [New registrations in June 2014] (in Swedish). Bil Sweden. Retrieved 2014-08-04. Download file "Nyregistreringar juni 2014.pdf" see table "Nyregistrerade miljöpersonbilar juni 2014" and "Nyregistrerade supermiljöbilar juni 2014" with summary of PEV sales by model between January and June 2014.
- EV Sales (2013-12-22). "Europe November 2013". Retrieved 2013-12-29.
- Jose Pontes (2014-07-28). "Europe June 2014 (Updated)". EVSales.com. Retrieved 2014-07-29. A total of 9,038 Outlander P-HEVs were sold in Europe during the first half of 2014.
- Jose Pontes (2014-07-30). "World Top 20 June 2014 (Special Edition)". EVSales.com. Retrieved 2014-07-30. A total of 14,810 Outlander P-HEVs were sold globally during the first half of 2014.
- Honda News (2013-06-21). "Honda introduces Accord hybrid and plug-in in Japan; hybrid in US in October". Green Car Congress. Retrieved 2014-02-22.
- Naoki Watanabe (2014-02-12). "Plug-in hybrids quickly becoming Japan's favorite way to drive green". Nikkei Asian Review. Retrieved 2014-02-19.
- Philippe Crowe (2013-10-22). "Outlander PHEV Now On Sale In Europe". HybridCars.com. Retrieved 2013-10-25.
- Jeff Cobb (2013-09-24). "US-Market Mitsubishi Outlander PHEV Delayed Until 2015". HybridCars.com. Retrieved 2013-09-25.
- Sebastian Blanco (2014-07-30). "Mitsubishi Outlander PHEV sales reach 33,000 worldwide". Autoblog Green. Retrieved 2014-08-03.
- Mark Kane (2014-07-14). "Outlander PHEV Drives Up Mitsubishi Sales In Europe". InsideEVs.com. Retrieved 2014-07-30.
- "三菱 i-MiEVなどの2014年8月度 生産・販売実績" [Mitsubishi i-MiEV production and sales results for August 2014] (in Japanese). Electric Vehicle News. 2014-09-29. Retrieved 2014-09-30.
- Automotive Industry Data (AID) (2013-12-17). "Mitsubishi Outlander PHEV top seller". AID. Retrieved 2013-12-26.
- Jose Pontes (2014-01-04). "Netherlands December 2013". EV Sales. Retrieved 2014-01-05.
- Michaël Torregrossa (2014-08-04). "Europe – Plus de 40.000 véhicules rechargeables vendus au premier semestre 2014" [Europe - Over 40,000 plug-in vehicles sold in the first half of 2014] (in French). Association pour l'Avenir du Véhicule Electrique Méditerranéen (AVEM). Retrieved 2014-08-09.
- Jay Cole (2014-05-13). "Jay Leno Gets First McLaren P1, Drives The Heck Out Of It On Normal Roads – video". InsideEVs.com. Retrieved 2014-05-30.
- Tom Burkart (2013-10-21). "2014 McLaren P1". TopSpeed. Retrieved 2013-10-28.
- Arman Barari (2013-02-26). "McLaren P1: Official Specs and Details". Motorward. Retrieved 2013-10-28.
- Mark Tisshaw (2013-11-13). "McLaren P1 sold out". Autocar. Retrieved 2013-11-23.
- Eric Loveday (2013-12-03). "2014 Porsche Panamera S E-Hybrid Sales Started In November". Inside EVs. Retrieved 2013-12-03.
- PR News Wire (2013-04-03). "Porsche introducing first plug-in hybrid with second generation of the Panamera". Green Car Congress. Retrieved 2013-09-06.
- Jay Cole (2014-09-03). "August 2014 Plug-in Electric Vehicle Sales Report Card". InsideEVs.com. Retrieved 2014-09-04. U.S. sales totaled 86 units in 2013 and 612 during the first eight months of 2014.
- Enrique García (2014-01-02). "Las matriculaciones de híbridos y eléctricos alcanzan ritmos históricos en Holanda" [Electric and hybrid car registrations reached historical records in the Netherlands] (in Spanish). AutoBlog en Español. Retrieved 2014-04-22.
- Staff (2014-07-03). "Verkoop Opel Ampera en Chevrolet Volt ingestort" [Opel Ampera and Chevrolet Volt sales collapsed] (in Dutch). Groen7. Retrieved 2014-09-08. Click on the link at the bottom of the article "Get the data" to download the file "data-0TdA9 (1).csv" with monthly sales by model. During the first half of 2014 a total of 1 McLaren P1 and 161 Porsche Panamera Plug-in Hybrids were sold.
- Mike Millikin (2014-09-12). "Porsche has sold more than 1,500 Panamera E-hybrid PHEVs this year; 9% of Panamera sales". Green Car Congress. Retrieved 2014-09-12.
- Eric Loveday (2013-05-09). "Plug-In Hybrid BYD Qin to Launch With Expected $29,000 Price Tag in June 2013". InsideEVs.com. Retrieved 2013-05-11.
- "BYD Announces Future Supercar With 3.9s 0-100". China Car Times. 2013-09-10. Retrieved 2013-09-11.
- John Voelcker (2012-04-20). "BYD Chin: World's First Plug-In Hybrid, Updated And Renamed". Green Car Reports. Retrieved 2012-04-21.
- "BYD Qin is Delayed Till December". China Car Times. 2013-11-04. Retrieved 2013-11-29.
- BYD Press release (2014-03-21). "BYD's Qin Electric Hybrid Now 'Best Selling Electric Car' in China". EV World. Retrieved 2014-03-21.
- Mat Gasnier (2014-08-19). "China 7 months 2014: Haval H6 up to record 7th place". Best Selling Cars Blog. Retrieved 2014-09-07. BYD Qin sales totaled 6,457 units during the first the first seven months of 2014.
- Mat Gasnier (2014-01-14). "China December 2013: Focus on the all-new models". Best Selling Cars Blog. Retrieved 2014-01-26. During 2013 Qin sales totaled 142 units.
- Klippenstein, Matthew (2014-02-10). "Plug-in electric car sales in Canada, Jan 2014". Green Car Reports. Retrieved 2014-02-13.
- "Cadillac ELR Sales Figures". Good Car Bad Car. October 2014. Retrieved 2014-10-05.
- Michael Harley (2012-10-01). "2014 Porsche 918 Spyder". Autoblog.com. Retrieved 2012-10-14.
- Jerry Garrett (2013-09-10). "Frankfurt Motor Show: The Record-Breaking Porsche 918 Spyder Has Arrived". The New York Times. Retrieved 2013-09-11.
- Eric Loveday (2014-03-10). "First BMW i8 Deliveries Scheduled For June – Final Performance / Fuel Consumption Figures Released". InsideEVs.com. Retrieved 2014-03-10.
- BMW Group Press Release (2013-09-10). "BMW unveils production i8 plug-in hybrid; 94 mpg; on sale in US in 2014 priced from $135,925". Green Car Congress. Retrieved 2013-09-10.
- Andreas Wehner (2014-10-10). "BMW legt im September weiter zu" [BMW Sales Growth Continues In September] (in German). KFZ-betrieb. Retrieved 2014-10-10. A total of 341 i8s were sold between June and September 2014.
- Eric Loveday (2013-09-03). "Volkswagen XL1 to be Priced at $146,000". InsideEVs.com. Retrieved 2013-09-03.
- Volkswagen Media Services (2013-02-21). "Volkswagen to produce XL1 diesel plug-in hybrid at Osnabrück; 261 mpg US". Green Car Congress. Retrieved 2013-02-21.
- Mike Szostech. "Audi A3 e-Tron Availability". MyAudiA3eTron.com. My Electric Car Forums. Retrieved 2014-09-29.
- Lewis Kingston (2013-05-31). "Audi A3 Sportback e-tron plug-in hybrid to arrive in 2014". Autocar. Retrieved 2013-06-02.
- Eric Loveday (2014-07-21). "Oft Delayed Audi A3 e-tron Pushed Back Again". InsideEVs.com. Retrieved 2014-07-28.
- VW Media (2014-02-21). "Volkswagen to introduce Golf plug-in hybrid at Geneva; first deliveries in autumn". Green Car Congress. Retrieved 2014-02-21.
- Kahn, C. (April 7, 2008)California Company Develops Plug-In Hybrid National Public Radio, accessed January 7, 2009, profiles EnergyCS, developing a Prius conversion service
- "How to Get a Plug-In Hybrid". Calcars.org. Retrieved 2010-11-27.
- "Hybrid Daily". Micro-Vett. Archived from the original on December 16, 2006. Retrieved April 21, 2007.
- Green Car Congress: EPRI, Ford and Eaton Developing Plug-in Hybrid Utility Trouble Truck. Retrieved April 23, 2007.
- Odyne Corporation press release: Odyne Corp. Announces Exclusive Agreement with Dueco, Inc.
- "Florida Plug-In Hybrid School Buses to Go into Service". Retrieved April 22, 2007.
- "UNEP news about plug-in school buses" (PDF). Retrieved 2010-11-27.
- Green Car Congress: Piaggio Launches Two Plug-In Hybrid Vespa Scooters. Retrieved April 28, 2007.
- Signal - AFCEA's International Journal "Hybrid Vehicle Cruises for Battle". Retrieved April 23, 2007.
- Hybrids by Fisher: Buses would double mpg. Retrieved August 18, 2008.
- Rijksdienst voor Ondernemend Nederland (RVO) (January 2014). "Cijfers elektrisch vervoer - Aantal geregistreerde elektrische voertuigen in Nederland - Top 5 geregistreerde modellen elektrische auto (31-12-2013)" [Figures electric transport - Number of registered electric vehicles in Netherlands and Top 5 registered electric vehicle models (12-31-2013)] (in Dutch). RVO (Dutch National Office for Enterprising). Retrieved 2014-09-17. See under the heading "31-12-2013" for total registrations figures at the end of December 2013.
- International Energy Agency, Clean Energy Ministerial, and Electric Vehicles Initiative (April 2013). "Global EV Outlook 2013 - Understanding the Electric Vehicle Landscape to 2020". International Energy Agency. Retrieved 2013-04-20. See pp. 4, 6-8, and 11-12.
- Electric Drive Transportation Association (EDTA) (2014-08-03). "Electric drive vehicle sales figures (U.S. Market) - EV sales". EDTA. Retrieved 2014-01-07. Fisker Karma sales are not included, which will increase the PHEV share by 1.2%.
- Toyota News (2014-01-15). "トヨタ自動車、 ハイブリッド車のグローバル累計販売台数が600万台を突破" [Toyota cumulative global sales of hybrid vehicles exceeded 6 million] (in Japanese). Toyota. Retrieved 2014-02-18. As of December 2013[update], cumulative sales in Japan totaled 15,400 units and global sales reached 48,600 units.
- Jeff Cobb (2014-01-16). "Top 6 Plug-In Vehicle Adopting Countries". HybridCars.com. Retrieved 2014-01-26.
- Mark Kane (2014-01-30). "Nissan LEAF Sales In Japan Up 17% in 2013". InsideEVs.com. Retrieved 2014-01-31. A total of 34,465 Leafs have been sold in Japan between December 2010 and December 2013.
- Mat Gasnier (2013-12-04). "Netherlands November 2013: Mitsubishi Outlander shoots up to pole position!". Best Selling Cars Blog. Retrieved 2013-12-26.
- Mat Gasnier (2014-01-03). "Netherlands December 2013: Mitsubishi Outlander at 12.7% share, Volvo V40 and V60 on podium". Best Selling Cars Blog. Retrieved 2014-01-05.
- Zachary Shahan (2013-03-07). "Electric vehicle market share in 19 countries - Plug-in Hybrid EV Market Share in 2013". ABB Conversations. Retrieved 2014-04-12.
- John Voelcker (2014-10-01). "Plug-In Electric Car Sales In Sept: Leaf Up Again, Volt Down". Green Car Reports. Retrieved 2014-10-15. As of September 2014[update], a total of 69,092 Chevrolet Volts have been sold in the U.S. since December 2010.
- Rijksdienst voor Ondernemend Nederland (RVO) (October 2014). "Cijfers elektrisch vervoer - Aantal geregistreerde elektrische voertuigen in Nederland - Top 5 geregistreerde modellen plug-in hybride elektrische voertuigen (30-09-2014) - Top 5 geregistreerde modellen volledig elektrische voertuigen (30-09-2014)" [Figures electric transport - Number of registered electric vehicles in Netherlands, Top 5 registered plug-in electric hybrid vehicle models (09-30-2014) and Top 5 registered all-electric vehicle models (09-30-2014)] (in Dutch). RVO (Dutch National Office for Enterprising). Retrieved 2014-10-15. See under the heading "30-09-2014" for total registrations figures at the end of September 2014.
- "Chevrolet Volt Sales Figures". Good Car Bad Car. October 2014. Retrieved 2014-10-15.
- Kraftfahrt-Bundesamtes (KBA). "Neuzulassungen von Personenkraftwagen im Dezember 2011 nach Segmenten und Modellreihen" [New registrations of passenger cars in December 2011 by segment and model lines] (in German). KBA. Retrieved 2012-10-15.A total of 241 Amperas and 25 Volts were sold through December 2011.
- Kraftfahrt-Bundesamtes (KBA) (January 2013). "Neuzulassungen von Personenkraftwagen im Dezember 2012 nach Marken und Modellreihen" [New registrations of passenger cars in December 2012 by make and model series] (in German). KBA. Retrieved 2013-01-14.
- Kraftfahrt-Bundesamtes (KBA) (January 2014). "Neuzulassungen von Personenkraftwagen im Dezember 2013 nach Segmenten und Modellreihen" [New registrations of passenger cars in December 2013 by segment and model series] (in German). KBA. Retrieved 2014-01-25.
- Kraftfahrt-Bundesamtes (KBA) (October 2014). "Neuzulassungen von Personenkraftwagen nach Segmenten und Modellreihen im September 2014" [New registrations of passenger cars in September 2014 by segment and model] (in German). KBA. Retrieved 2014-10-10.
- Mat Gasnier (2013-02-01). "UK Full Year 2012: Now with Top 350 All-models ranking!". Best Selling Cars Blog. Retrieved 2013-02-07.
- Jay Nagley (2013-09-16). "Price cut to jolt Vauxhall Ampera sales". Autocar. Retrieved 2013-10-02. 150 Amperas and 23 Volts were sold during the first half of 2013.
- Ben Lane (2014-08-07). "UK electric fleet passes 13,000 mark". Zap Map. Retrieved 2014-08-17.
- Vereinigung Schweizer Automobil-Importeure. "Autoverkäufe nach Modellen - Modellstatistik" [Passenger cars by model - Statistics by model] (in German). Auto Schweiz Suisse. Retrieved 2014-08-04. Under "Modellstatistik" download the xls file "Januar - Juni 2014" for 2014 sales, and under "Modellstatistiken 2008–2013" click "2013 Statistik" to download the file "ModellePW2013" with sales by model for 2013.
- Vereinigung Schweizer Automobil-Importeure. "Autoverkäufe nach Modellen - Modellstatistik" [Passenger cars by model - Statistics by model] (in German). Auto Schweiz Suisse. Retrieved 2014-10-15. Under "Modellstatistik" download the xls file "Januar - September 2014" for 2014 sales.
- Michaël Torregrossa (2014-01-19). "Hybride rechargeable – Le marché français stagne en 2013" [Rechargeable hybrids - The French market stagnated in 2013] (in French). Association pour l'Avenir du Véhicule Electrique Méditerranéen (AVEM). Retrieved 2014-01-25.
- Michaël Torregrossa (2013-01-15). "Voitures hybrides – Le bilan des immatriculations 2012 en France" [Hybrid Cars - The balance of 2012 registrations in France] (in French). Association pour l'Avenir du Véhicule Electrique Méditerranéen (AVEM). Retrieved 2013-01-25.
- Jose Pontes (2014-07-14). "France June 2014". EVSales.com. Retrieved 2014-08-05.
- "Belgium November 2012: Discover the Top 338 All-models ranking". Best Selling Car Blog. 2012-12-04. Retrieved 2012-12-07.
- Jose Pontes (2014-01-18). "Belgium December 2013". EV Sales. Retrieved 2014-01-25.
- Jose Pontes (2014-08-07). "Belgium June 2014". EVSales.com. Retrieved 2014-08-08.
- Mat Gasnier (2014-07-31). "Belgium June 2014: Renault Mégane #1, Captur on podium". Best Selling Cars Blog. Retrieved 2014-08-06.
- "Over 10.000 ladbare biler på norske veier" [Over 10,000 plug-in cars in Norwegian roads] (in Norwegian). Grønn bil. 2013-01-04. Retrieved 2013-07-05.
- Staff (2014-01-08). "Over 20.000 ladbare biler på norske veier" [Over 20,000 rechargeable electric cars on Norwegian road] (in Norwegian). Grønn bil. Retrieved 2014-01-25.
- Ståle Frydenlund (2014-07-18). "Snart 10.000 nye elbiler registrert" [Almost 10,000 new EVs registered] (in Norwegian). Norsk Elbilforening (Norwegian Electric Vehicle Association). Retrieved 2014-08-04.
- KFZ- Wirtschaftsverlag (2014-01-01). "Aktuelle Zulassungsstatistik" [current registration statistics] (in German). Automotive.co.at. Retrieved 2014-01-22. See data for "Jän - Dez 2013" and "Jän - Dez 2012"
- Jose Pontes (2014-07-15). "Austria June 2014". EVSales.com. Retrieved 2014-08-05.
- Mat Gasnier (2013-01-05). "Australia Full Year 2012: Mazda3 leads again in record market, no local model on podium for the first time since 1930s!". Best Selling Car Blog. Retrieved 2013-01-18.
- Mat Gasnier (2014-01-16). "Australia Q4 2013: Jeep Grand Cherokee shines". Best Selling Cars Blog. Retrieved 2014-01-25.
- Byron Mathioudakis (2014-07-17). "Nissan to keep ‘plugging away’ on Leaf EV". Go auto. Retrieved 2014-08-16.
- Bil Sweden (2014-10-01). "Nyregistreringar september 2014" [New registrations in September 2014] (in Swedish). Bil Sweden. Retrieved 2014-10-04. Download file "Nyregistreringar september 2014.pdf" see table: "Nyregistrerade supermiljöbilar september 2014" with summary of plug-in passenger car sales by model between January and September 2014. A total of 2,505 plug-in hybrids were registered during these nine months.
- John Voelcker (2013-01-03). "Plug-In Electric Car Sales Triple In 2012 As Buyers, Models Increase". Green Car Reports. Retrieved 2013-01-03.
- Jon LeSage (2013-01-08). "Toyota Prius Plug-In wins 2012 sales battle in UK". AutoblogGreen. Retrieved 2013-02-10.
- Faye Sunderland (2014-01-07). "Plug-in car sales boom on back of recovering car market". The Green Car Website. Retrieved 2014-01-26. 509 Prius PHVs were sold 2013.
- Timothy Cain (October 2014). "Toyota Prius Plug-In Sales Figures". Good Car Bad Car. Retrieved 2014-10-15.
- Jose Pontes (2014-01-15). "Finland December 2013". EV Sales. Retrieved 2014-01-26.
- Jose Pontes (2014-08-23). "Finland June 2014". EV Sales. Retrieved 2014-08-23.
- Jose Pontes (2013-01-13). "Spain Full Year 2012". EV Sales. Retrieved 2013-06-29. 58 units sold in 2012.
- Asociación Nacional de Importadores de Automóviles, Camiones, Autobuses y Motocicletas (ANIACAM) (2014-01-02). "Datos de Mercado: Diciembre 2013 - Matriculaciones de automóviles" [Market data: December 2013 - Automobiles registrations] (in Spanish). ANIACAM. Retrieved 2014-01-26.Download the file "DossierAutomóviles_diciembre13.xls (929KB)" with current month and cumulative sales for 2013.
- Asociación Nacional de Importadores de Automóviles, Camiones, Autobuses y Motocicletas (ANIACAM) (October 2014). "Datos de Mercado: Septiembre 2014 - Matriculaciones de automóviles" [Market data: September 2014 - Automobiles registrations] (in Spanish). ANIACAM. Retrieved 2014-10-18. Download the file "DossierAutomóviles_septiembre14.xls (929KB)" with current month and cumulative sales between January and September 2014.
- Alex Grant (2014-07-08). "Japanese manufacturers lead growing UK electric and hybrid vehicle sales". Fleet World. Retrieved 2014-08-03.
- Jose Pontes (2014-07-14). "Germany June 2014". EVSales.com. Retrieved 2014-08-04.
- Jose Pontes (2014-01-20). "Germany December 2013". EVSales.com. Retrieved 2014-01-25.
- Jose Pontes (2014-01-06). "Italy December 2013". EVSales.com. Retrieved 2014-01-26.
- Jose Pontes (2014-07-12). "Italy June 2014". EVSales.com. Retrieved 2014-08-04.
- Wang Chuanfu (2014-09-14). "New energy car sales boosted in China by gov't subsidies". Want China Times. Retrieved 2014-10-14. BYD Qin sales totaled 7,773 units during the first eight months of 2014.
- Guotai Junan (2014-10-16). "Automotive industry: September new car sales growth accelerated energy". Wantinews.com. Retrieved 2014-10-16.
- Staff (2014-01-10). "Plug-in EV Sales in China Rose 37.9% to 17,600 in 2013". China Auto Web. Retrieved 2014-01-26. BYD F3DM sales totaled 1,005 units in 2013.
- "Ventas en España de coches híbridos en 2012" [Sales in Spain of hybrid cars in 2012]. Motorpasion Futuro (in Spanish). 2013-01-13. Retrieved 2013-05-31. A toal of 8 F3DMs were sold in Spain in 2011 and 2 more in 2012.
- Klippenstein, Matthew (2014-07-14). "Plug-in electric car sales in Canada, June 2014". Green Car Reports. Retrieved 2014-08-03.
- Mat Gasnier (2013-06-17). "Germany Full Year 2012: Now available with model splits!". Best Selling Cars Blog. Retrieved 2013-09-15.
- Jose Pontes (2013-01-22). "France Full Year 2012". EV Sales. Retrieved 2013-07-19. A total of 21 Fisker Karmas were registered in 2012.
- Jose Pontes (2014-01-24). "France December 2013 (Updated)". EVSales.com. Retrieved 2014-01-25. Fisker Karma registrations totaled 12 units in 2013.
- Staff (2014-10-10). "Nieuwe registraties elektrische personenauto's" [Registrations of new electric passenger cars] (in Dutch). Autoblog Netherlands. Retrieved 2014-10-15. Graph linked to the article Verkoop stekkerauto’s blijft achter (Sales of plug-in cars lag behind).
- Enrique García (2014-01-17). "Asi fueron las ventas de híbridos y eléctricos en España durante 2013" [So were the sales of hybrids and electrics in Spain in 2013]. Auto Blog en Español (in Spanish). Retrieved 2014-09-12.
- Enrique García (2014-08-11). "Asi fueron las ventas de híbridos y eléctricos en España durante julio" [So were the sales of hybrids and electrics in July]. Auto Blog en Español (in Spanish). Retrieved 2014-09-12.
- "BMW Group Sales Growth Continues In September" (Press release). Munich: CNBC. 2014-10-10. Retrieved 2014-10-15.
- Society of Motor Manufacturers and Traders(SMMT) (2014-01-07). "December 2013 – EV and AFV registrations". SMT. Retrieved 2014-01-25. A total of 992 plug-in hybrids were registered during 2012 and 1,072 in 2013.
- Society of Motor Manufacturers and Traders(SMMT) (2014-10-06). "September 2014 – EV registrations". SMT. Retrieved 2014-10-16. A total of 4,303 plug-in electric cars were registered during the first nine months of 2014.
- Kraftfahrt-Bundesamtes (KBA) (October 2014). "Monatliche Neuzulassungen - Neuzulassungsbarometer im September 2014" [Monthly registrations - New registrations Barometer in September 2014] (in German). KBA. Retrieved 2014-10-09. A total of 9,100 plug-in electric vehicles were registered during the first nine months of 2014 consisting of 3,053 plug-in hybrids and 6,047 electric cars. Includes vehicles registered by car manufacturers and the automobile industry for research, demonstration and promotional purposes.
- Kraftfahrt-Bundesamtes (KBA). "Monatliche Neuzulassungen - Neuzulassungsbarometer im Dezember 2013" [Monthly registrations - New registrations Barometer in December 2013] (in German). KBA. Retrieved 2014-09-06. A total of 1,385 plug-in hybrids and 6,051 all-electric cars were registered during 2013. Includes vehicles registered by car manufacturers and the automobile industry for research, demonstration and promotional purposes.
- "Ladbare biler i Norge mar, 2014" [Rechargeable cars in Norway in March, 2014] (in Norwegian). Grønn bil. March 2014. Retrieved 2014-04-22. Click "Utvikling" for sales split between all-electric and plug-in hybrids by year: cumulative registrations through March 2014: 25,710 all-electric passenger and light-duty vehicles and 1,176 plug-in hybrids.
- "Notice 2009-89: New Qualified Plug-in Electric Drive Motor Vehicle Credit". Internal Revenue Service. 2009-11-30. Retrieved 2010-04-01.
- "State and Federal Incentives for EVs, PHEVs and Charge Stations". Plug In America. Retrieved 2010-05-29.
- Paul Hudson (2010-02-28). "£5,000 grant to buy plug-in electric cars". London: The Daily Telegraph. Retrieved 2010-04-23.
- "Ultra-low carbon cars: Next steps on delivering the £250 million consumer incentive programme for electric and plug-in hybrid cars". Department for Transport. July 2009. Retrieved 2010-04-23.
- Paul Hockenos (2011-07-29). "Europe’s Incentive Plans for Spurring E.V. Sales". The New York Times. Retrieved 2011-07-31.
- "Overview of Purchase and Tax Incentives for Electric Vehicles in the EU". European Automobile Manufacturers Association. 2011-03-14. Retrieved 2011-07-31.
- Evarts, E. (January 11, 2008) "Charge! Fuel economy law promotes plug-in hybrids," Consumer Reports Cars Blog. Retrieved January 15, 2008.
- "Barack Obama and Joe Biden: The Change We Need | New Energy for America". My.barackobama.com. 2008-06-22. Retrieved 2009-04-11.
- "President Obama Announces $2.4 Billion for Electric Vehicles". Apps1.eere.energy.gov. Retrieved 2010-11-27.
- "Loc.gov" (PDF). Retrieved 2010-11-27.
- "Conference Results: Stunning Expansion of Plug-In Tax Credits". Calcars.org. 2009-02-12. Retrieved 2009-04-11.
- "Do You Realize Plug-Ins Get $5-$10+ Billion in Stimulus Package?". Calcars.org. 2008-12-31. Retrieved 2009-04-11.
- "EERE News: President Obama Announces $2.4 Billion for Electric Vehicles". Apps1.eere.energy.gov. 2009-03-19. Retrieved 2009-04-11.
- Department of Energy - DOE Announces $30 Million for Plug-in Hybrid Electric Vehicle Projects
- "Energy.gov". Apps1.eere.energy.gov. Retrieved 2010-11-27.
- Department of Energy and Sweden Sign MOU to Advance Market Integration of Plug-in Hybrid Vehicles
- San Francisco Office of the Mayor (November 20, 2008) "Mayors Aim to Make San Francisco Bay Area the Electric Vehicle Capital of the U.S." sfgov.org
- "SF Plug-In Vehicle Bonanza:Watch Video, Read About It". Calcars.org. Retrieved 2009-04-11.
- "Climate Change - What are we doing about it in Washington State? - Electrify Transportation". Ecy.wa.gov. Retrieved 2010-11-27.
- "Seattle Mayor Introduces City's First PHEV". Green Car Congress. 2008-05-31. Retrieved 2010-11-27.
- "GM Media Online". Media.gm.com. 2009-02-03. Retrieved 2009-04-11.[dead link]
- "Ec.europa.eu". Ec.europa.eu. Retrieved 2010-11-27.
- World Wildlife Foundation (April 2, 2008) "Cars should plug-in to a new future" panda.org
- "Obama's Briefing; Sandalow To DOE; Automaker News; Nat'l Wildlife Federation Embraces PHEVs". Calcars.org. 2009-03-27. Retrieved 2009-04-11.
- "Progress on Prepayment Plan/Battery Worry Hype". Calcars.org. Retrieved 2009-04-11.
- "Plug-In Endorsements: Inauguration + Senate '09 Freedom Act". Calcars.org. 2009-01-16. Retrieved 2009-04-11.
- "Senate Alert/GM Reaches Out/EDTA/Tracking Carmakers/TED/Wellinghoff". Calcars.org. Retrieved 2009-04-11.
- "Set America Free Coalition - Energy Independence through Fuel Choice - Home". Setamericafree.org. Retrieved 2010-11-27.
- "Plug-in Hybrid Electric School Bus". Advancedenergy.org. Retrieved 2010-11-27.
- "Businesswire.com". Businesswire.com. 2009-09-24. Retrieved 2010-11-27.
- Shnayerson, Michael (1996-08-27). The Car That Could: The Inside Story of GM’s Revolutionary Electric Vehicle. Random House. pp. 194–207, 263–264. ISBN 978-0-679-42105-4.
- Coker, M. (2003-05-15). "Dude, Wheres My Electric Car!?!". Orange County Weekly. Retrieved 2009-10-08.
- Greenberg J. (2008-10-14). "The Edison of our Age: Stan Ovshinsky and the Future of Energy (Video Interview Part 1)". The Energy Roadmap. Retrieved 2009-10-08.
|Wikimedia Commons has media related to Plug-in electric hybrid-powered vehicles.|
|Wikiquote has quotations related to: Plug-in hybrid|
- BMW i3 REx vs. Chevrolet Volt: two different approaches to plug-in hybrids, Torque News, June 2014
- eGallon Calculator: Compare the costs of driving with electricity, U.S. Department of Energy
- How Plug-In Hybrid Cars Work at HowStuffWorks
- US Office of Energy Efficiency and Renewable Energy
- Plug-In Hybrid Electric Vehicle Value Proposition Study Final Report, July 2010.
- Plug-in Hybrid Electric Vehicles.
- Alternative Fuels and Advanced Vehicles Data Center (AFDC), including list of books and publications.
- DoE Grant for Plug In Hybrid Electric Vehicle (PHEV) Technology Acceleration And Deployment Activity.
- US National Highway Traffic Safety Administration
- "Plugging into the Grid" by Joseph J. Romm and Peter Fox-Penner in the Progressive Policy Institute's March 2007 newsletter, explaining how PHEVs can help "break America's oil addiction and slow global warming"
- Energy Storage and Transportation - Idaho National Laboratory
- Plug-In.com - Plug-in and Hybrid News, Comparisons, Discussion.
- Plugging In: A Consumer’s Guide to the Electric Vehicle Electric Power Research Institute
- List of Plug-in Vehicles (Plug In America).
- Transport Action Plan: Urban Electric Mobility Initiative, United Nations, Climate Summit 2014, September 2014
Past conferences and events
- The Brita Climate Ride 2009 September 26–30 (charity bike ride from New York City to Washington, DC)
- The Business of Plugging In 2009: October 19–21, 2009, Motor City, Detroit, Michigan
- PHEV '09 September 28–30, 2009 (Montreal, Quebec, Canada).
- Beyond Oil: Transforming Transportation, October 23–24 (Redmond, WA). The sixth annual Cascadia Center for Regional Development TransTech Conference, to be held at Microsoft's Redmond campus.
- Plug-In Electric Vehicles 2008 by the Brookings Institution and Google.org.
- Hybridfest.com: July 19–20, 2008, Madison, WI
- Plug-in 2008: July 22–24, 2008, San Jose, California
- Beyond oil, Transforming Transportation: September 4–5, 2008, in Redmond, Washington. Fifth Annual Cascadia-Microsoft Conference on Transportation Technology, co-sponsored by Microsoft, the US Department of Transportation, the Idaho National Laboratory, PEMCO, Washington DOT and the Puget Sound Clean Air Agency.
- TechKnowForum.org: Plug-In Hybrids & the Smart Grid: October 23, 2008, Ann Arbor, Michigan
- Hybridfest Green Drive Expo: July 18–19, 2009, Madison, Wisconsin
- Plug-in 2009: August 10–13, 2009, Long Beach, California
- "High-tech vehicles growing more common in region: Plug-in cars give owners a real jolt of satisfaction" (Seattle Post-Intelligencer, September 9, 2008)
- "The Plug-in Revolution :A grand plan for America’s energy woes" (Washington Monthly, October 2008)
- Boschert, S. (March 12, 2007) "Plug-In Hybrids" Corte Madera, California: fora.tv
- Ford Escape plug-in hybrid electric sport utility vehicle (Ford Environmental, January 5, 2008)
- New Chevy Volt exterior wind tunnel testing (April 2008)
- The Race For The Electric Car (60 Minutes, CBS News, October 6, 2008)
- Daimler VideoCast: The new Sprinter Plug-In-Hybrid commercial van (19 February 2009)
Books and studies
- American Council for an Energy-Efficient Economy, Plug-in Electric Vehicles: Challenges and Opportunities, June 2013
- Boschert, Sherry (2007). Plug-in Hybrids: The Cars that will Recharge America (1st ed.). New Society Publishers. ISBN 0-86571-571-8.
- 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
- Nevres, Cefo (2009). Two Cents per Mile: Will President Obama Make it Happen With the Stroke of a Pen?. Nevlin LLC,. ISBN 978-0-615-29391-2.
- Sandalow, editor, David B. (2009). Plug-In Electric Vehicles: What Role for Washington? (1st. ed.). The Brookings Institution. ISBN 978-0-8157-0305-1.
- U.S. Environmental Protection Agency, Application of Life-Cycle Assessment to Nanoscale Technology: Lithium-ion Batteries for Electric Vehicles, April 2013.