Hybrid electric

Hybrid-electric vehicles are electrically-driven vehicles (see electric vehicle) which rely not only on batteries but also on an internal combustion engine driving a generator to provide the electricity.

There are several great advantages to this configuration:

• The vehicle is lighter and roomier than a purely electric vehicle, because it does not need to carry nearly as many batteries
• The internal-combustion engine in a hybrid-electric can be much smaller and lighter, getting far better gas mileage than in a conventional vehicle, because the engine runs at a relatively constant speed, and does not need to provide direct power for acceleration, which is the biggest reason for large engines
• Braking can be configured to recapture part of the kinetic energy of movement that is otherwise lost in a conventional vehicle

Of course, there are also some disadvantages:

• The initial vehicle is costlier due to the extra hardware as for example large batteries and generators
• Due to the additional hardware the weight is increased
• Maintenance cost may increase as more hardware has to be maintained and repaired if necessary
• Some hybrid electric vehicles hold parts of the additional hardware in the trunk, resulting in a reduced storage capacity

The first successful hybrid-electric car was engineered by Ferdinand Porsche in 1928. Since then, hobbyists have built such cars but no such car was put into production until the twenty-first century, when Honda Insight and Toyota Prius were the commercially available hybrid models. These vehicles have a direct linkage from the internal combustion engine to the drive, so that the engine can provide acceleration power. (See Gas-electric hybrid engine, hybrid car, diesel-electric locomotive) Prototypes of plug-in hybrid cars, with larger battery packs that can be re-charged from the power grid, have been built in the U.S., and one production PHEV, the Renault Kangoo, went on sale in France in 2003.

Toyota has announced that it intends that all its vehicles will have a hybrid electric version by 2012.