Hybrid Car Concept

A hybrid electric vehicle (HEV) or Hybrid Car is a car which combines a conventional propulsion system with an on-board rechargeable energy storage system (RESS) to achieve better fuel economy than a conventional car without being hampered by range from a charging unit like an electric car. The different propulsion power systems may have common subsystems or components.

HEVs most commonly use an internal combustion engine (ICE) and electric batteries to power electric motors. Modern mass produced HEVs prolong the charge on their batteries by capturing kinetic energy via regenerative braking, and some 

HEVs can use the combustion engine to generate electricity by spinning an electrical generator (often a motor-generator) to either recharge the battery or directly feed power to an electric motor that drives the car. This contrasts with battery electric cars which use batteries charged by an external source. Many HEVs reduce idle emissions by shutting down the ICE at idle and restarting it when needed. An HEV's engine is smaller and may be run at various speeds, providing more efficiency.

HEVs are viewed by some automakers as a core segment of the future automotive market In an article for the July-August issue of THE FUTURIST magazine titled "Energy Diversity as a Business Imperative", GM vice president for environment and energy Elizabeth Lowery is quoted as saying, "Today, we are embracing multiple energy sources because there is no single answer available for the mass market…. In 2007, GM will debut four hybrid models—with many more in the years to follow."

Benefits of the hybrid electric design include:

• Fuel consumption Current HEVs reduce petroleum consumption (compared to otherwise similar conventional cars) primarily by using three mechanisms: a) Reducing wasted energy during idle/low output, generally by turning the ICE off; b) Recapturing waste energy (i.e. regenerative braking); c) reducing the size and power of the ICE engine, and hence inefficiencies from under-utilization, by using the better torque response of electric motors to compensate for the loss in peak power output from the smaller ICE. Any combination of these three primary hybrid technologies may be used for different fuel usage, power, emissions, weight and cost profiles. The ICE in an HEV is smaller, lighter, and more efficient than the one in a conventional car, because the combustion engine can be sized for slightly above average power demand rather than peak power demand. A standard combustion engine is required to operate over a range of speed and power, yet its highest efficiency is in a narrow range of operation; in an HEV, the ICE operates within its range of highest efficiency. The power curve of electric motors is better suited to variable speeds and can provide substantially greater torque at low speeds compared with internal-combustion engines. The greater fuel economy of HEVs has implication for reduced petroleum consumption and car air pollution emissions worldwide

• Durability Reduced wear on the gasoline engine, particularly from idling with no load. Reduced wear on brakes from the regenerative braking system use.

• Environmental impact Reduced noise emissions resulting from substantial use of electric motor at low speeds, leading to roadway noise reduction and beneficial noise health effects. Note, however, that this is not always an advantage; for example, people who are blind or visually-impaired, and who rely on car-noise while crossing streets, find it more difficult to do safely. Reduced air pollution emissions due to lower fuel consumption, leading to improved human health with regard to respiratory and other illness. Pollution reduction in urban environments may be particularly significant due to elimination of idle-at-rest.