Hybrid vehicle

A hybrid vehicle is a machine that uses two or more distinct types of power to function.

Most people associate the term with hybrid electric vehicles. These machines combine an internal combustion engine with an electric motor. Other systems might use pressurized fluid, which are known as hydraulic hybrids. The main goal of a hybrid powertrain is to switch between power sources. This switching maximizes fuel efficiency and energy efficiency. Using these systems can also lower emissions and reduce the costs of running the vehicle.

In a hybrid electric vehicle, the two power sources have different strengths. An electric motor is highly efficient at producing torque. Torque is the turning power required to get a vehicle moving from a stop. Conversely, a combustion engine is better suited for maintaining high speeds.

There are different ways these systems work together. In a parallel hybrid, the human or motor torques are mechanically coupled. In a series hybrid, one power source might only act as a generator. This generator charges a battery or feeds a motor that provides all the torque.

Hybrid technology can be applied to many different sizes of transport. Small scale examples include two-wheeled vehicles like mopeds or electric bicycles. In these cases, the rider's muscles act as one of the power sources. For much larger machines, hybridization can reduce conversion losses. Large vehicles can distribute power through wires or pipes instead of mechanical parts. This is very useful when powering multiple drives, such as several wheels or propellers.

This method is common in heavy goods vehicles, buses, and even large ships.

History shows that humans have experimented with hybrid power for a long time. Non-nuclear submarines are among the oldest production hybrids. These vessels use diesel engines while surfaced and batteries when submerged.

In the late 19th century, inventors created prototype motorcycles using hybrid principles. In 1975, Augustus Kinzel published a patent for a series hybrid bicycle. Later, in 1994, Bernie Macdonalds conceived the Electrilite SHB. This design allowed for regenerative braking and pedaling while the rider was stationary. These early developments paved the way for modern hybrid systems.

Rail transport has seen significant advancements through hybridization. In India, the railway launched a CNG-diesel hybrid train in January 2015. This train uses a 1400 hp engine with fumigation technology. Compressed Natural Gas, or CNG, is a less-polluting alternative to diesel. In the United States, General Electric developed a locomotive using sodium-nickel chloride battery storage. This improvement was expected to increase fuel economy by more than 10 percent.

Other specialized locomotives, like the Green Goat, claim fuel savings of 40 to 60 percent. These engines are often built by reusing the frames of retired yard locomotives.

Heavy road vehicles and industrial machines also benefit from these systems. Companies like FedEx are trialling delivery trucks that use diesel generators and electric motors. These diesel engines run at a constant RPM to reach peak efficiency. In the world of port logistics, engineers are testing hybrid power for Rubber Tyred Gantry cranes.

These cranes lift heavy shipping containers. The energy used to lift a container can be partially regained when the crane lowers it. Engineers predict this could reduce diesel fuel and emissions by 50 to 70 percent.

Even the sky and the sea utilize hybrid concepts. Some modern ships use large towing kites to capture wind energy. In aviation, the Boeing Fuel Cell Demonstrator uses a unique combination. It uses a Proton-Exchange Membrane fuel cell paired with lithium-ion batteries.

The fuel cell provides power during the long cruise phase of flight. The batteries provide the extra power needed for takeoff and climbing. This shows how hybrid technology connects to many different fields of science and engineering.