The Hybrid vehicle is an automobile that uses more than one propulsion systems to provide motive power. In most cases the combination is a gasoline-electric base, which uses gasoline for powering internal combustion and electric batteries to power the vehicle.
Hybrid vehicles can be found in a variety of combinations. Two of them are the most common and they are the series hybrids and the parallel hybrids. One system is common among hybrid vehicles: the regenerative breaking method. It recovers energy when the automobile slows down by running the motor in a backwards direction. Energy saving is sometimes done by shutting down the combustion engine when it is not needed. Several features need to be modified if a hybrid vehicle system is built.
In such designs the internal combustion engine is independent from the drivetrain. On the other hand it powers the electrical generator, which becomes responsible for powering the drivetrain. The energy given by generators is aimed directly towards the motors that move the car and if there is too much it can be used to recharge the battery. Many prototypes also use more motors, sometimes two or three for each wheel, with the purpose of increasing car performance. Most vehicles using the series hybrid system are used by automobiles that have often stops in their traveling.
The most common hybrids nowadays are the parallel hybrids. They will provide a connection with both the internal combustion systems and the electrical combustion systems. In most cases a bigger and more powerful electric generator is linked with the motor, creating one functional body. Efficiency is gained by many methods and the usage of more electric generators to power other functions of the car (like air conditioning) is common.
Fuel used for hybrid vehicles can come from a variety of sources:
- Gasoline – most hybrid vehicles are fueled by gasoline. Different levels of ethanol created from the renewable energy source can be mixed and the usage of up to 15% ethanol provides an added plus.
- Diesel – diesel engines have the advantage of providing more constant energy over a longer period of time, with less wear being shown. The only problem that appears relies on the acceleration achieved, which is inferior to gasoline based hybrids. Also, diesel vehicles do not need to use petroleum at all, running entirely on biodiesel.
- Fuel cells – In these models the fuel cell is used mainly to store auxiliary energy.
- Steam and turbines – Although at the present moment no hybrid car runs a steam engine, the popularity and benefits it showed in the past can produce the need for such a hybrid model.
- Hybrid fuel
- Human power – usually in motorized bicycles.