Hybrid cars have begun to live up to their potential to provide an advance in gasoline efficiency for automobiles, but not all consumers know what a hybrid car is, or how it works. A hybrid is anything that mixes the traits of two different things to create a new whole; this is true for hybrid vegetables, as well as cars. When one talks about a hybrid car what is really being discussed is a gas-electric hybrid car: A car with both an electric motor and a gasoline motor.
The reasons for combining the two are simple: Both gasoline engines and electric motors have disadvantages when applied to automobiles. The disadvantages to electric motors are pretty severe: Because batteries (at this time) are heavy and bulky for the amount of energy they can store it is impossible to have a reasonably sized car powered solely by an electric motor that has a range of more than about 90 miles, and refueling is a time-consuming process often taking 8 to 12 hours.
This is fine for driving around town and many daily commutes, but few people want to purchase a car that they can’t take for a long or moderate trip. Additionally, electric cars have difficulties navigating hills, and high speeds, where the current draw would exceed the safe limits of the batteries. Gasoline vehicles also have their own disadvantages: because the engine has to operate over such a wide range of RPMs it is impossible to tune the engine to operate at one RPM for maximum efficiency.
But both electric motors and gasoline engines have advantages as well. A gasoline-powered vehicle can store enough fuel onboard for 300-400 miles at a single fill-up, and when the reservoir of fuel is low, refilling the car’s supply of fuel is a quick operation taking a matter of minutes.
An electric motor driven car can gain a huge increase in efficiency by recovering the energy of motion when it comes time to brake the vehicle by having the motor act as a generator it will not only slow the vehicle but store some of the energy of motion back in the battery where it can be used again to make the car move once more when the light changes again.
In a gas-electric hybrid vehicle, the two power sources are used together to offset the flaws that each has on their own. The electric motor portion of the vehicle operates just like a normal electric car, including allowing for recovery of braking energy. For most in-town driving the car acts entirely as a battery-operated vehicle.
The size of the battery in the gas-electric hybrid is much smaller than it would be in a pure electric vehicle, but that’s because the gas-electric doesn’t have to store all its energy in the battery for use. When the charge of the battery is getting low, or during periods of high draw from the battery a small gasoline engine,
attached to an electric generator, starts up, and supplies additional energy to the battery and to the electric motor as needed. Because the gasoline engine is only used to turn the generator it need only operate at one, optimum RPM setting, allowing for it to be tuned to maximum efficiency. Also, by having the gasoline engine available to convert gasoline to electric energy, the short-range of a purely electric driven car is overcome as well.
The gasoline-electric hybrid vehicle is a very successful marriage between two older automobile technologies that allows for each to mask the shortcomings of the other.