What is a hybrid?
A hybrid electric vehicle (HEV) is a compromise between a standard gas-powered car and an electric vehicle, combining the long driving range and speed benefits of gasoline engines and the economic and environmental benefits of electric motors. Much like a gas-powered car, a HEV has a fuel tank that supplies gasoline to the engine, and the engine turns a transmission, which turns the wheels.
HEV's have smaller engines than conventional cars. The vehicle store and use electricity generated from the gas engines, reducing the amount of gasoline needed to power the vehicle. The engine also generates power for the electric motor and is capable of recharging the electric motor's battery at higher speeds. Therefore, the regenerative features of the car make its use of gasoline more efficient, extending the miles per gallon and reducing emissions. The vehicle only needs to accommodate the average load, rather than the peak load. As a result, hybrid vehicles use less energy and are therefore, more efficient.
How do hybrids work?
The electric motor of a HEV handles normal stop-and-go travel and initial highway acceleration. When the vehicle hits higher speeds, the gasoline-powered engine kicks in.
The HEV's battery feeds power to the electric motor and is able to recharge when the vehicle is coasting and braking. The power switching process the vehicle undergoes between the two types of engines enables the vehicle to use less gasoline and reduce pollution.
What is a PHEV?
PHEV's use the same technology as popular hybrids on the road today. A PHEV is a hybrid is a hybrid that is fitted with an additional battery, allowing the vehicle to be recharges from a standard 120-volt electrical outlet. The battery takes approximately five hours to charge in a standard outlet, which would cost the average electric customer less than 50 cents.
What is a NEV?
NEV's are compact vehicles designed to be used in residential areas with low density traffic and low speed zones. With a top speed of 25 mph, low-speed vehicles can be used on streets with a posted 35 mph speed limit or less. When driven on public streets, a driver's license is required. The green vehicles are powered by rechargeable batteries and electric motors. Depending on the size and options, a full battery charge will take from 8 to 10 hours.
How is PHEV different?
Both standard hybrids and PHEV's are powered by a combination of electricity and liquid fuels; however, PHEV's draw their charge from the engine and captured brake energy, as well as from the electrical grid when they are plugged into an electrical outlet. PHEV's also have a set of batteries that provide electricity to an electric motor, allowing the battery pack to be even further recharged by "plugging-in."
PHEV's have traditional fuel tanks and inernal combustion engines, so they do not face the range limitation of electric-only cars. As a result, the vehicles can travel up to 30 miles on electricity before using the standard, gas-electric operating system and get up to 100+ miles per gallon.
What are the benefits?
PHEV owners can expect up to an 85 percent reduction in gasoline use. PHEV's also get about twice the fuel economy than a standard hybrid. The electric equivalent of a gallon of gas costs less than $1 a gallon.
Greenhouse gas emissions are significantly reduced with HEV's and PHEV's.
Are Plug-in Hybrids (PHEV's) available today?
There are prototypes in operation today, but there are no commercially available PHEV's on the market. There are also many conventional hybrids, from sedans to SUV's, that have been converted to plug-ins. Some are getting up to 60 all-electric miles per charge.
How much gasoline would a PHEV use?
According to the Electric Power Research Institute (EPRI), half the cars on U.S. roads are driven 25 miles a day or less. Consequently, a plug-in with a 25-mile all electric range could eliminate gasoline use in the daily commute of tens of millions of Americans. Furthermore drivers of PHEV's would only need to fill up with fuel a few times a year, versus the current 24-36 times a year on average.
Will PHEV's be slow?
No. A Toyota Prius, modified with a larger plug-in battery, has essentially the same accelerating power and speed capability of a current hybrid.
How much more will a PHEV cost than a conventional hybrid?
EPRI estimates that, with mass production, the cost of a PHEV battery will add $2,000 to $3,000 to the cost of a conventional hybrid. Battery costs are likely to fall with increased production.