Fuels Are a Source of Energy

All around us we see machines doing work. For example, planes, trains, and automobiles carry us along roads, over land and sea, or across town. These machines require fuels to function. They burn gasoline, natural gas, jet fuel, diesel, propane, or other fuels in their engines.

Fuels are portable energy sources. By burning them, we can harness their energy to do work. Sometimes we simply burn fuels out in the open, such as wood in a campfire. In industrialized countries like the United States, it is more common to burn fuels in specialized machines such as furnaces.

Many machines we're familiar with don't seem to use fuel, though. Think about washing machines, electric stoves, and air conditioners. These use electrical energy rather than burning a fuel. But where does the electric power come from?

Electricity comes from fuels. Usually a fuel such as coal, oil, or gas is burned at a power plant to boil water for steam. The steam spins turbines to produce electrical energy, which in turn powers the machines in your home.

Let's look at some of the different kinds of fuels available to us.