In 1769, Nicolas-Joseph Cugnot built the first self-propelled vehicle which was powered by steam made by heating water from burning wood. The steam was then passed to engine to drive the wheels. However it was too slow and heavy to be useful.

Then in 1861, Thomas Rickett’s steam carriage used coal as the fuel.

The Benz Patent-Motorwagen of 1886 was the first modern car. Its engine ran on petrol. The fuel was burned inside the engine. This type of engine is known as the internal combustion engine that is used in cars till date.

Several car manufacturers are developing hydrogen fueled cars. These cause less pollution than petrol and diesel vehicles.

Most hydrogen-powered vehicles use fuel cells, in which energy is released from hydrogen in a carefully controlled manner and reacts with oxygen.

We can model the reaction in a fuel cell using a word equation: hydrogen + oxygen → water

In the hydrogen fuel cell in the bus below, hydrogen fuel releases energy that is transferred to electricity to make the bus move.

Hydrogen gas is flammable. In the 1930s, airships were built to carry passengers long distances. Many were filled with hydrogen, which made them float in air. In May 1937, the Hindenburg airship burst into flames. The flames quickly spread as the hydrogen reacted with oxygen in the air. The accident killed 35 of the 97 people on board.

Fuels

A fuel is a chemical or nuclear substance from which stored energy can be transferred usefully (usually in the form of heat and light.) Examples of fuels:

• Firewood
• Hydrogen
• Biofuel
• Fossil fuels
• Nuclear fuels