Jump to content

Plug-in hybrid: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
76...108: you need sources for these kinds of claims (34 mph?) and shouldn't delete other sources, please
sentences were logical fallacies and irrelevent, see comments
Line 166: Line 166:
=== Cost, weight, and size of batteries ===
=== Cost, weight, and size of batteries ===


Disadvantages of plug-in hybrids include the additional cost, weight, and size of a larger [[battery pack]].
Disadvantages of plug-in hybrids include the additional cost, weight, and size of a larger [[battery pack]]. General Motors may allow buyers of its [[Chevy Volt]] electric car to rent the vehicle's battery, offsetting some cost.<ref>Simon, B. ([[August 12]], [[2007]]) [http://www.ft.com/cms/s/f455b442-48fc-11dc-b326-0000779fd2ac.html "GM eyes electric-car initiative"] ''Financial Times'' accessed [[19 September]] [[2007]]</ref> Also [[used good|used]] PHEV batteries can be sold to electric utilities to be employed at [[electrical substation]]s.<ref name="woody">Woody, Todd. [http://blogs.business2.com/greenwombat/2007/06/photo_green_wom.html "PG&E's Battery Power Plans Could Jump Start Electric Car Market".] (Blog). ''Green Wombat'', [[2007]]-[[06-12]]. Retrieved on [[2007]]-[[08-19]].</ref>


=== Electrical outlets outside garages ===
=== Electrical outlets outside garages ===

Revision as of 15:35, 25 May 2008

Hybrids Plus plug-in hybrid Toyota Prius conversion with PHEV-30 (30 mile or 48 km all-electric range) battery packs

A plug-in hybrid electric vehicle (PHEV) is a hybrid vehicle with batteries that can be recharged by connecting a plug to an electric power source. It shares the characteristics of both conventional hybrid electric vehicles and battery electric vehicles, having an internal combustion engine and batteries for power. Most PHEVs on the road today are passenger cars, but there are also PHEV versions of commercial passenger vans, utility trucks, school buses, motorcycles, scooters, and military vehicles. PHEVs are sometimes called grid-connected hybrids, gas-optional hybrids, or GO-HEVs.

The cost for electricity to power plug-in hybrids for all-electric operation in California has been estimated at less than one quarter of the cost of gasoline (petrol.)[1] Compared to conventional vehicles, PHEVs can reduce air pollution and dependence on petroleum, and lessen greenhouse gas emissions that contribute to global warming. Plug-in hybrids use no fossil fuel during their all-electric range if their batteries are charged from nuclear or renewable energy sources. 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 applications.[2]

As of April 2008, plug-in hybrid passenger vehicles are not yet in production. However, Toyota,[3] General Motors,[4] Ford,[5] Chinese automaker BYD Auto,[6] and California startups Fisker Automotive[7] and Aptera Motors[8] have announced their intention to introduce production PHEV automobiles. The PHEV-60 BYD F6DM sedan and F3DM hatchback are expected in 2009;[9] the luxury Fisker Karma PHEV-50 sports car is slated for late 2009; and the Toyota Prius and GM's PHEV-40 Chevrolet Volt and Saturn Vue plug-ins are expected in 2010.[10][11] Conversion kits and services are available to convert production model hybrid vehicles to plug-ins.[12][13] Most PHEVs on the road in the U.S. are conversions of 2004 or later Toyota Prius models, which have had plug-in charging added and their electric-only range extended.

Terminology

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 without using its internal combustion engine, or about 32 kilometers, so it may also be designated as a PHEV32km.[14]

The Energy Independence and Security Act of 2007 defines a plug-in electric drive vehicle as a vehicle that:

This distinguishes PHEVs from regular hybrid cars mass-marketed today, which do not use any electricity from the grid.

The Institute of Electrical and Electronics Engineers (IEEE) defines PHEVs similarly, but also requires that the hybrid electric vehicle can drive at least ten miles (16 km) in all-electric mode (PHEV-10 / PHEV16km), while consuming no gasoline or diesel fuel.[15]

History

Hybrid vehicles were produced beginning as early as 1899 by Lohner-Porsche. 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 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.[16] The car could be plugged into a standard North American 110 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'cite" 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.[17] 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 litres (2.6 US 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 220 volts supply.[18] 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,[17] the Elect'road was redesigned in 2007.

Lithium-ion battery pack, with cover removed, in a CalCars "PRIUS+" plug-in hybrid converted Toyota Prius converted by EnergyCS

In September 2004, the California Cars Initiative (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.[19]

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."[3] Toyota has said it plans to migrate to lithium-ion batteries in future hybrid models,[20] but not in the next-generation Prius, expected in fall 2008.[21] Lithium-ion batteries are expected to significantly improve fuel economy, and have a lower weight-to-energy ratio, but cost more to produce, and raise safety concerns due to high operating temperatures.[21]

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).[4] The model's sale is anticipated by fall 2009,[21] and GM announced in January 2007 that contracts had been awarded to two companies to design and test lithium-ion batteries for the vehicle.[22] GM has said that they plan on introducing plug-in and other hybrids "for the next several years".[4]

In January 2007, GM unveiled the Chevrolet Volt, which is expected to initially feature a plug-in capable, battery-dominant series hybrid architecture which they are calling E-Flex.[23] 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.[24] General Motors presented the Volt as a PHEV-40 that starts its engine when 40% of the battery charge remains, and which can achieve a fuel economy of Template:Mpg, even if the vehicle's batteries are not charged.[25]

On July 9, 2007, Ford Motor Company CEO Alan Mulally said he expects Ford to sell plug-in hybrids in five to ten years, the launch date depending on advances in lithium-ion battery technology. Ford will provide Southern California Edison with 20 Ford Escape Hybrid sport utility vehicles reconfigured to work as plug-ins by 2009, with the first by the end of 2007.[5]

On July 25, 2007, 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 plug-in Prius has an all-electric range of 13 km (8 mi).[26]

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. Announcing an agreement with A123Systems, Lutz said GM would like to have their planned Saturn Vue plug-in on the roads by 2009.[11] The Volt has an all-electric range of 40 mi (64 km).

On September 5, 2007, Quantum Technologies[27] and Fisker Coachbuild, LLC announced the launch of a joint venture in Fisker Automotive.[28] Fisker intends to build a US$ 80,000 luxury PHEV-50, the Fisker Karma, anticipated in late 2009.[7]

In September 2007, Aptera Motors announced their Typ-1 two-seater. They plan to produce both an electric Typ-1e and a plug-in hybrid Typ-1h with a common three-wheeled, composite body design. As of May 2008, over two thousand pre-orders have been accepted, and production is expected to begin in late 2008.[8]

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 iron-based batteries instead of lithium-ion, and can be recharged to 70% of capacity in just 10 minutes.[6]

In January 2008, a privately-run waiting list to purchase the Chevy Volt reached 10,000 members. The list, administered by Lyle Dennis, was started one year prior.[29]

January 2008: Assistant professor Yi Cui and colleagues at Stanford University's Department of Materials Science and Engineering [30] have made a discovery to use silicon nanowires to give rechargeable lithium ion batteries 10 times more charge.[31]

On March 27, 2008, the California Air Resources Board modified their regulations, requiring automobile manufacturers to produce 58,000 plug-in hybrids during 2012 through 2014.[32] This requirement is an asked-for alternative to an earlier mandate to produce 25,000 pure zero emission vehicles, reducing that requirement to 5,000.[33]

Technology

Powertrains

The Chevrolet Volt concept car is a series plug-in hybrid, meaning that its mechanical engine power is exclusively converted to electricity, not used directly.

PHEVs are based on the same three basic powertrain architectures as conventional hybrids:[34]

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 capacitor pack, or a combination of the two, can be used to store excess charge. Examples of series hybrids include the Renault Kangoo Elect'Road, Toyota's Japan-only Coaster light-duty passenger bus, DaimlerChrysler's hybrid Orion bus, the Chevrolet Volt concept car, the Opel Flextreme concept car, 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.[35]

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.[36]

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.[37]

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:[38]

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.[39]

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.[40] 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.

File:Renault-Kangoo-Plug-in-hybrid2.jpg
The redesigned Renault Kangoo Elect'road operates in blended mode, using engine and battery power simultaneously.

Blended mode is a type of charge-depleting mode 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.[41] 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.

Mixed mode describes a trip in which a combination of the above modes are utilized.[42] 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 back 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.[43] Design issues and trade-offs against battery life, capacity, heat dissipation, weight, costs, and safety need to be solved.[44] Advanced battery technology is under development, promising greater energy densities by both mass and volume,[45] and battery life expectancy is expected to increase.[46]

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.[47]

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.[48] However, plug-in hybrids typically use larger battery packs than comparable conventional hybrids, and thus require more resources. Recently Pacific Gas and Electric Company (PG&E) has suggested that utilities could purchase used batteries for backup and load levelling purposes. They state that while these used batteries may be no longer usable in vehicles, their residual capacity still has significant value.[49]

Lithium iron phosphate (LFP) is a kind of cathode material of lithium iron phosphate batteries that is getting attention from the industry. The most important merit of this battery type is safety and high-power. LiFePO4 is one of three major compounds and technology in LFP family. The other two are Nanophosphate,and NanoCocrystallineOlivine.

In France, Électricité de France (EDF) and Toyota are installing recharging points for PHEVs on roads, streets and parking lots.[50] EDF is also partnering with Elektromotive, Ltd.[51] to install 250 new charging points over six months from October 2007 in London and elsewhere in the UK.[52] Recharging points also can be installed for specific uses, as in taxi stands. Project Better Place has begun in October 2007 and is working with Renault on development of exchangeable batteries (battery swapping).[53]

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.[54] The UltraBattery combines a supercapacitor and a 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).[55]

Conversions of production hybrids

15 lead-acid batteries, PFC charger, and regulators installed into WhiteBird, a PHEV-10 conversion of a Toyota Prius

Conversion of an existing production hybrid to a plug-in hybrid 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.[56] Some of the systems have involved replacement of the vehicle's original NiMH battery pack and its electronic control unit. Others, such as 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).[57] Within the electric vehicle conversion community this has been referred to as a "hybrid battery pack configuration".[58] 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.[19]

EDrive Systems use Valence Technology Li-ion batteries and have a claimed 40 to 50 miles (64 to 80 km) of electric range.[59] 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) [60].

The EAA-PHEV project was conceived by CalCars and the Electric Auto Association in October of 2005 to accelerate efforts to document existing HEVs and their potential for conversion into PHEVs.[61] It includes a "conversion interest" page.[62] 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. The PbA Battery Box Assembly is a complete install pack that provides access to the spare tire and contains 20 PbA20-12 lead-acid batteries, plus all high voltage components and control electronics in a strong welded steel enclosure with plastic powder coat finish. The PbA Battery Box Assembly is also available without batteries. Expect about 10 miles of EV mode range. [63] [64]

Advantages

Fuel efficiency

Claimed fuel economy for PHEVs depends on the amount of driving between recharges. If no gasoline is used the MPG equivalent depends only on the efficiency of the electric system. A 120 km (70 mile) range PHEV-70 may annually require only about 25% as much gasoline as a similarly designed PHEV-0, depending on how it will be driven and the trips for which it will be used.[2] The furthest all-electric range in a PHEV planned for mass production is the PHEV-60 BYD F6e.

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.[39] 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.[65]

Greenhouse gas emissions

Another advantage of PHEV adoption is a predicted reduction in carbon emissions. Increased drivetrain efficiency results in significant reduction of greenhouse gas emissions, even taking into account energy lost to inefficiency in the production and distribution of grid power and charging of batteries. 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 CO2 emissions compared to the driver of a regular hybrid, based on the 2005 distribution of power sources feeding the U.S. electrical grid.[66] Additionally, for PHEVs recharged in areas where the grid is fed by power sources with lower CO2 emissions than the current average, net CO2 emissions associated with PHEVs will decrease correspondingly.

A large-scale June 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.[67] 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 CO2 emissions using a portfolio of existing techniques, including efficient vehicles.

The ACEEE study predicts that in areas where more than 80% of grid-power comes from coal-burning power plants, local net CO2 emissions will increase.[66] However, given the global nature of problems associated with CO2 emissions, specifically global warming, localized increases in CO2 emissions are not considered a significant problem if global CO2 emissions are decreased.[14]

GM Vice Chairman Bob Lutz has said the Chevy Volt will emit 40 grams of carbon dioxide per kilometer. That is well below the proposed European Union emission standards of 120-130 g/km.[68]

Martin Eberhard, who co-founded plug-in maker Tesla Motors, says "if you do the math, you´ll find that an electric car, even if you use coal to make electricity, produces less pollution per mile than burning gasoline in the best gasoline-powered car."[69] The Minnesota Pollution Control Agency found that if Minnesota's fleet of vehicles making lengthy trips were placed by plug-in hybrids, it would produce more carbon dioxide emissions per mile than existing hybrid vehicles unless more than 40% of the electricity used to charge them came from non-polluting sources such as hydro or wind.[70] 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.[71]

Operating costs

George W. Bush is shown the PHEV Mercedes-Benz Sprinter van in the U.S. Postal Service

In a 2006 research estimate in California, the cost to plug in at night was equivalent to US$0.75 per U.S. gallon (3.8 L) of gasoline,[1] whereas the pre-tax cost of gasoline is just under US$3 per gallon. The cost of electricity for a Prius PHEV is about US$0.03 per mile (US$0.019 per km), based on Template:KWh/mile and a cost of electricity of US$0.10 per kilowatt hour.[72][73] During 2008, many government and industry researchers are focusing on determining what level of all-electric range is economically optimum for the design.[74] In 2008, a PHEV can travel 30 miles for just US$ 1.04 (the same mileage as a gallon of gasoline costing $3.00.)[75]

Vehicle-to-grid electricity

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.[14]

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.[76] 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.[77]

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[78] and EDrive[79] 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.[80]

In September 2006, the California Air Resources Board held a Zero Emission Vehicle symposium that included several presentations on V2G technology.[81] In April 2007, Pacific Gas and Electric 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.[82] 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.[83]

Federal Energy Regulatory Commissioner Jon Wellinghoff 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.[84]

Disadvantages

Cost, weight, and size of batteries

Disadvantages of plug-in hybrids include the additional cost, weight, and size of a larger battery pack.

Electrical outlets outside garages

Many people living in apartments, condominiums, and townhouses do not have garages. With only on-street parking available, they will need access to electrical outlets to take advantage of all-electric operation. New electrical outlets near their places of residence, or in commercial or public parking lots will need to be installed for them to gain the full advantage of PHEVs.[85]

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.[71] 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.[86] 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.[87]

Public deployment and pilot projects

Public deployment includes:

Commercialization

The number of US survey respondents willing to pay US$4,000 more for a plug-in hybrid car increased from 17% in 2005 to 26% in 2006.

PHEVs have been sold as commercial passenger vans,[89] utility trucks,[90][91] general and school buses,[92][93] motorcycles,[94] scooters,[95] and military vehicles.[96] Hybrid Electric Vehicle Technologies, Inc converts diesel buses to plug-in hybrids, under contract for the Chicago Transit Authority.

Interest in plug-in hybrids increased in 2006 to such a level that the architecture was included as an area of research in President George W. Bush's advanced energy initiative and mentioned in his 2007 State of the Union Address. Incentives for the development of PHEVs are included in the Energy Independence and Security Act of 2007.[97]

At least fourteen car companies of all sizes are exploring or planning to offer a plug-in.[98] After hearing an explanation of PHEVs, 49% of U.S. consumers surveyed in 2006 said they would consider purchasing one. That is about the same level of interest as standard hybrid technology.[99]

As of February, 2008, all three of the major U.S. presidential candidates have taken a position on plug-in hybrids:

  • Senator Barack Obama delivered a speech on February 28, 2006 calling for every government car to be a PHEV.[100] On April 19, 2007, Obama joined with senators Maria Cantwell and Republican Orrin Hatch to introduce legislation providing: tax credits to consumers who purchase plug-ins, patterned after existing incentives for conventional hybrids; tax incentives for the U.S. production of PHEVs and dedicated parts; and incentives for electric utilities to provide rebates to customers who purchase plug-ins, scaled to provide larger incentives to utilities producing greener energy.[101]
  • Senator John McCain pledged on April 23, 2007 to promote partnerships between utilities and automakers to accelerate the deployment of plug-in hybrids.[102]
  • Senator Hillary Clinton called on February 11, 2008 for investment in research and to stimulate demand for the first commercial PHEVs by investing $2 billion in research and development to reduce the cost and increase the longevity and durability of batteries; offering consumers tax credits of up to $10,000 for purchasing a plug-in hybrid; and adding 100,000 plug-in hybrids to the federal fleet by 2015.[103]

Patent encumbrance of NiMH batteries

In 1994, General Motors acquired a controlling interest in Ovonics's battery development and manufacturing, including patents controlling the manufacturing of large nickel metal hydride (NiMH) batteries. In 2001, Texaco purchased GM's share in GM Ovonics. A few months later, Chevron acquired Texaco. In 2003, Texaco Ovonics Battery Systems was restructured into Cobasys, a 50/50 joint venture between Chevron and Energy Conversion Devices (ECD) Ovonics.[104] Chevron's influence over Cobasys extends beyond a strict 50/50 joint venture. Chevron holds a 19.99% interest in ECD Ovonics.[105] Chevron also maintains veto power over any sale or licensing of NiMH technology.[106] In addition, Chevron maintains the right to seize all of Cobasys' intellectual property rights in the event that ECD Ovonics does not fulfill its contractual obligations.[106] On September 10, 2007, Chevron filed a legal claim that ECD Ovonics has not fulfilled its obligations. ECD Ovonics disputes this claim.[107] Since that time, the arbitration hearing was repeatedly suspended while the parties negotiate with an unknown prospective buyer. No agreement has been reached with the potential buyer. [108]

In her book, Plug-in Hybrids: The Cars that Will Recharge America, published in February 2007, Sherry Boschert argues that large-format NiMH batteries are commercially viable but that Cobasys refuses to sell or license them to small companies or individuals. Boschert reveals that Cobasys accepts only very large orders for these batteries. When Boschert conducted her research, major auto makers showed little interest in large orders for large-format NiMH batteries. However, Toyota employees complained about the difficulty in getting smaller orders of large format NiMH batteries to service the existing 825 RAV-4EVs. Since no other companies were willing to make large orders, Cobasys was not manufacturing nor licensing any large format NiMH battery technology for automotive purposes. Boschert concludes that "it's possible that Cobasys (Chevron) is squelching all access to large NiMH batteries through its control of patent licenses in order to remove a competitor to gasoline. Or it's possible that Cobasys simply wants the market for itself and is waiting for a major automaker to start producing plug-in hybrids or electric vehicles."[109]

However, recently-signed Cobasys contracts demonstrate that the company is willing to use its NiMH technology in the automotive industry, specifically for use with hybrid electric vehicles. In December 2006, Cobasys and General Motors announced that they had signed a contract under which Cobasys provides NiMH batteries for the Saturn Aura hybrid sedan.[110] In March 2007, GM announced that it would use Cobasys NiMH batteries in the 2008 Chevrolet Malibu hybrid as well. Cobasys remains unwilling to sell NiMH batteries in smaller quantities to individuals or companies interested in building or retrofitting their own PHEVs.[citation needed]

Still other actions by Cobasys suggest that the company remains unwilling to make NiMH battery technology economically feasible for the development of automobiles that rely on electric motor technology more than currently available hybrid cars. In October 2007, International Acquisitions Services, Inc., Innovative Transportation Systems AG and Neville Chamberlain filed suit against Cobasys and its parents for refusing to fill a large, previously agreed-upon order for large-format NiMH batteries to be used in the electric Innovan. [111]

Electro Energy Inc., working with CalCars, converted a Prius using its own bipolar NiMH batteries. Plug-In Conversions uses Nilar NiMH batteries and the EAA-PHEV open source control system in its Prius PHEV conversions. These organizations maintain that these developments are allowable because their NiMH battery technologies are not covered by Cobasys' patents.

See also

Template:EnergyPortal

References

  1. ^ a b Frank, A., et al., "What are Plug-In Hybrids?" Team Fate (University of California, Davis) Retrieved 7 August 2007; earlier version
  2. ^ a b Simpson, A. (2006) Cost-Benefit Analysis of Plug-in Hybrid Electric Vehicle Technology (PDF) National Renewable Energy Laboratory conference report CP-540-40485
  3. ^ a b Thomas, Ken (19 July 2006). "Toyota charging ahead with plans for plug-in hybrid". Chicago Sun-Times/Associated Press. {{cite news}}: Check date values in: |date= (help)
  4. ^ a b c General Motors (November 29, 2006) "GM Announces Intention to Produce Plug-in Hybrid SUV" accessed 1 June 2007
  5. ^ a b Woodall, B. (July 10, 2007) "Ford sees plug-in hybrids in 5–10 years" Reuters accessed 27 July 2007
  6. ^ a b Edmunds (15 October 2007) "Detroit Show Preview: BYD's New Plug-in Hybrid on Sale Next Year" Edmunds Inside Line retrieved 26 October 2007
  7. ^ a b Shirouzu, N., and Buckman, R. (January 14, 2008) "Electric-Car Firms Get Star Investors," Wall Street Journal
  8. ^ a b Aptera Motors (2007) "FAQs" Aptera web site accessed January 21, 2008
  9. ^ Martinez, N. (7 April 2008) "BYD China looking to build Euro hybrids by 2010" Motor Trend
  10. ^ Woodall, B. (10 November 2007) "Toyota eyes the plug-in Prius" Reuters retrieved 9 November 2007
  11. ^ a b Terlep, S. (August 10, 2007) "GM races ahead with plug-in car" The Detroit News accessed 6 September 2007
  12. ^ Wald, M.L. (January 13, 2008) "Closing the Power Gap Between a Hybrid’s Supply and Demand," New York Times
  13. ^ California Company Develops Plug-In Hybrid profiles EnergyCS, which is developing a Prius conversion method.
  14. ^ a b c James, W. (September 2006) "Large Oil and GHG Reductions with Plug-in Hybrid Vehicles" Alternative Transport Energies Conference (Perth, Australia)
  15. ^ IEEE-USA Board of Directors (15 June 2007) "Plug-In Electric Hybrid Vehicles" Position Statement retrieved 3 October 2007
  16. ^ "Hybrid Car Ready in 1969" (Blog entry). Finkbuilt. January 9, 2007. Retrieved on August 7, 2007.
  17. ^ a b Renault (March 10, 2003) "Kangoo reinvents the electric car" (PDF) press release
  18. ^ Holinger, H. (2003) "Renault Electric Kangoo Can Do" EVWorld.com accessed July 6, 2007.
  19. ^ a b "How We Green-Tuned an '04 Prius into a PRIUS+ Plug-In Hybrid!". CalCars.com - The California Cars Initiative. {{cite web}}: Unknown parameter |accessmonthday= ignored (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help)
  20. ^ Lithium Ion Likely to Power Hybrids of the Future Hybrid Synergy View Newsletter, Toyota, April 2007. Retrieved on 2007-08-07.
  21. ^ a b c Halvorson, Bengt. Li-ion Not Ready for Prius. BusinessWeek, June 18, 2007. Retrieved on 2007-08-07.
  22. ^ GM Awards Lithium-Ion Battery Development Contracts. GM, January 4, 2007. Retrieved on 2007-08-07.
  23. ^ General Motors (January 7, 2007) "Chevrolet Volt..." press release; video
  24. ^ Green Car Congress (January 15, 2007) The Volt May be First, But E-Flex is the Key accessed 28 April 2007
  25. ^ Abuelsamid, S. (January 7, 2007) "Detroit Auto Show: It's here. GM's plug-in hybrid is the Chevy Volt Concept" AutoBlogGreen
  26. ^ Toyota Motor Corporation (July 25, 2007) "Japan Certifies Toyota Plug-in Hybrid for Public-road Tests" JCN Newswire accessed July 25, 2007
  27. ^ Quantum Technologies
  28. ^ "Drive the Future with Fisker Automotive, A New Green American Premium Car Company" (PDF). 5 September 2007. {{cite news}}: Check date values in: |date= (help)
  29. ^ Dennis, L.J. (January 26, 2008) "Chevy Volt Waiting List Hits 10,000 Members," GM-Volt.com accessed January 26, 2008
  30. ^ Yi Cui Group
  31. ^ [1], [2]
  32. ^ "Preliminary Summary of Air Resources Board Action (3/27/08) - Zero Emission Vehicle (ZEV) Program" www.arb.ca.gov
  33. ^ "CARB backs off a bit on ZEV Mandate, orders 66k PHEVs sold by 2014" autoblog.com
  34. ^ Union of Concerned Scientists (2006) "Hybrids Under the Hood (part 2) -- Drivetrains" Hybridcenter.org accessed 31 May 2007
  35. ^ Layton, J. and Nice, K. (2007) "How Hybrid Cars Work" HowStuffWorks.com accessed 19 June 2007
  36. ^ BC Climate Exchange (2005) "Hybrid Basics" Hybrid Experience Report accessed 19 June 2007
  37. ^ Toyota Motor Corporation (2006) "Series Parallel Hybrid System" Hybrid Synergy Drive accessed 19 June 2007
  38. ^ Green Car Congress (September 29, 2006) Plug-ins Progress accessed 27 April 2007
  39. ^ a b 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
  40. ^ Tony Markel/NREL: "Plug-in HEV Vehicle Design Options and Expectations" (PDF) accessed 27 April 2007
  41. ^ Santini, et al (September 27, 2006) Energy and Petroleum Consumption Attributes of Plug-in Hybrids (PDF), accessed 29 April 2007
  42. ^ EAA-PHEV wiki: Mixed-mode accessed 29 April 2007
  43. ^ Roim, J. and Frank, A. (April 2006) "Hybrid Vehicles Gain Traction" (PDF) Scientific American pp. 72–9
  44. ^ Bullis, K. (August 3, 2006) "Are Lithium-Ion Electric Cars Safe?" Technology Review (Cambridge, Mass.: MIT)
  45. ^ Fleissner, C. (8/14/06) "Johnson Controls partnership wins new contract" Wisconsin Technology Network
  46. ^ Altair Nanotechnologies Inc. (September 7, 2006) "Altair Nanotechnologies Details Long Life Features of Its Nano-Titanate Battery" Business Wire press release
  47. ^ Voelcker, J. (January 2007) "Lithium Batteries for Hybrid Cars" IEEE Spectrum
  48. ^ Toyota Motor Co (2004) "Hybrid Hype? Fact and Fiction Surrounding the New Technology" Toyota.com accessed 8 July 2007
  49. ^ Cite error: The named reference woody was invoked but never defined (see the help page).
  50. ^ Électricité de France (5 September 2007) "EDF et Toyota annoncent un partenariat technologique en Europe relatif aux véhicules hybrides rechargeables" press release retrieved 10 October 2007
  51. ^ Elektromotive, Ltd. (2007) "Elektromotive: The ultimate zero-emission transport system" company web site retrieved 26 October 2007
  52. ^ Reynolds, L. (October 11, 2007) "UK to install 250 new public charging stations by next spring". The Battery Vehicle Society retrieved 26 October 2007
  53. ^ [3], [4]
  54. ^ [5] , [6]
  55. ^ "Ultrabattery Sets New Standard For Hybrid Electric Cars" in Space Daily, January 21, 2008
  56. ^ California Cars Initiative (2007) "Where Plug-In Hybrid Conversions (mostly Priuses) Are" accessed July 8, 2007.
  57. ^ A123 Systems, Inc. (May 3, 2007) A123Systems Battery Co Acquires Hymotion Conversion Co Business Wire press release
  58. ^ Electric Auto Association (2007) "Battery Pack Configurations" Plug in Hybrid Electric Vehicle website, accessed 25 April 2007
  59. ^ EDrive Systems, LLC (2006) "EDrive FAQ" accessed July 6, 2007.
  60. ^ OEMtek: Prius Plug-in Hybrid Electric Vehicle (PHEV) - Home
  61. ^ Electric Auto Association "Plug in Hybrid Electric Vehicle" wiki (2005–present)
  62. ^ Conversion Interest - EAA-PHEV
  63. ^ Plug-In Supply
  64. ^ Luscious Garage PHEV conversions
  65. ^ U.S. Dept. of Energy (18 September 2007) "Plug-In Hybrid Electric Vehicle Conversions" Alternative Fuels and Advanced Vehicles Data Center retrieved 8 November 2007
  66. ^ a b Kliesch, J. and Langer, T. (September 2006) "Plug-In Hybrids: an Environmental and Economic Performance Outlook" American Council for an Energy-Efficient Economy
  67. ^ 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 accessed July 21, 2007
  68. ^ Green Car Congress (10 September 2007) "GM Unveils Opel Flextreme: Plug-in Diesel Hybrid Variant of E-Flex" retrieved 1 October 2007
  69. ^ CBS News (September 16, 2007) "Could The Electric Car Save Us?" CBS News Sunday Morning retrieved 26 October 2007
  70. ^ Minnesota Pollution Control Agency (200 [http://www.pca.state.mn.us/publications/p-gen4-01.pdf "Air Emissions Impact of Plud-In Hybrid Vehicles in Minnesota's Passenger" Fleet March 2007
  71. ^ a b 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 accessed July 21, 2007
  72. ^ California Cars Initiative (April 20, 2006) "Fact Sheet: PHEV Conversions" (PDF) page 2, accessed 18 April 2006
  73. ^ Bluejay, M. (2006?) "How much does electricity cost?" accessed 18 April 2007
  74. ^ U.S. Dept of Energy (June 2007) "Plug-In Hybrid Electric Vehicle R&D Plan", section 1.5: Collaboration, accessed 12 July 2007.
  75. ^ Ford Escape plug-in prototype shows potential - USATODAY.com
  76. ^ 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. accessed April 23, 2007
  77. ^ Green Car Congress (26 September 2005) "Toyota Dream House with Plug-In Prius" accessed 23 April 2007
  78. ^ EnergyCS (USA) and Amberjac (UK)
  79. ^ EDrive Installation
  80. ^ Green Car Congress (18 November 2005) "Plugging the Plug-In Hybrid" accessed 20 April 2007
  81. ^ Green Car Congress (September 27, 2006) The Plug-In and BEV Adoption Wild Card: Vehicle-to-Grid accessed April 28, 2007
  82. ^ Green Car Congress (April 9, 2007) "PG&E Demonstrates Vehicle-to-Grid Technology" accessed April 20, 2007
  83. ^ News.com (April 9, 2007) "PG&E sees plug-in hybrids as potential profit centers"
  84. ^ Liotsakis, P. (2007) "Cars, Power Plants and 'Cash Back Hybrids'" LiveNeutral (Presidio School of Management and Chicago Climate Exchange) accessed 12 July 2007.
  85. ^ San Francisco Department of the Environment (September 4, 2007) "Response to the Findings and Recommendations of the 2006–2007 Civil Grand Jury in Their Report: 'Can San Francisco Keep Its Promise to Reduce Greenhouse Gas Emissions'" (Recommendation B7c) accessed 30 October 2007
  86. ^ Clayton, M. (September 25, 2006) "A reality check on plug-in hybrids" The Christian Science Monitor
  87. ^ Kanellos, M. (April 28, 2006) "Plug in your hybrid, pollute less?" cNet News.com
  88. ^ http://www.ecy.wa.gov/climatechange/washington_electrifytransportation.htm
  89. ^ "Hybrid Daily". Micro-Vett. {{cite web}}: Unknown parameter |accessmonthday= ignored (help); Unknown parameter |accessyear= ignored (|access-date= suggested) (help)
  90. ^ Green Car Congress: EPRI, Ford and Eaton Developing Plug-in Hybrid Utility Trouble Truck accessed April 23, 2007
  91. ^ Odyne Corporation press release: Odyne Corp. Announces Exclusive Agreement with Dueco, Inc.
  92. ^ "Florida Plug-In Hybrid School Buses to Go into Service" accessed 22 April 2007
  93. ^ UNEP news about plug-in school buses
  94. ^ Enertia Bike
  95. ^ Green Car Congress: Piaggio Launches Two Plug-In Hybrid Vespa Scooters accessed April 28 2007
  96. ^ Signal - AFCEA's International Journal "Hybrid Vehicle Cruises for Battle" accessed April 23, 2007
  97. ^ Evarts, E. (January 11, 2008) "Charge! Fuel economy law promotes plug-in hybrids," Consumer Reports Cars Blog accessed January 15 2008
  98. ^ CalCars (2008) "How Carmakers are Responding to the Plug-In Hybrid Opportunity" calcars.org accessed January 22, 2008
  99. ^ Synovate (August 16, 2006) "Survey shows 49% of consumers would consider buying a plug-in hybrid" accessed July 8, 2007.
  100. ^ Remarks of Senator Barack Obama, Governor's Ethanol Coalition, Washington, DC
  101. ^ Cantwell, Hatch, Obama Announce Plan to Promote Plug-In Hybrid Vehicles
  102. ^ John McCain's Speech On Energy Policy
  103. ^ Hillary Clinton Press Release: Hillary’s Plan to Create a Green Jobs Revolution
  104. ^ Roberson, J. (March 14, 2007) "Supplier Cobasys exploring more hybrid batteries" Detroit Free Press
  105. ^ ECD Ovonics Definitive Proxy Statement of January 15, 2003
  106. ^ a b ECD Ovonics Amended General Statement of Beneficial Ownership of December 2, 2004
  107. ^ ECD Ovonics 10-Q Quarterly Report for the period ending September 30, 2007
  108. ^ ECD Ovonics 10-Q Quarterly Report for the period ending March 31, 2008
  109. ^ Boschert, S. (2007) Plug-in Hybrids: The Cars that Will Recharge America (Gabriola Island, BC: New Society Publishers) ISBN 9780865715714
  110. ^ Abuelsamid, S. (December 6,2006) "Cobasys providing NiMH batteries for Saturn Aura hybrid" Autobloggreen.com
  111. ^ ECD Ovonics 10-Q Quarterly Report for the period ending March 31, 2008
Groups promoting plug-ins
Conferences and events
News