- Most of the electricity used in the world is generated from power plants that burn fossil fuels to heat water and make steam.
- Three forms of fossil fuels are: coal, which is a hard, black, rock-like substance made up of carbon, hydrogen, oxygen, nitrogen, and sulfur; oil, which is a liquid fossil fuel that is sometimes called petroleum; and natural gas, which is primarily made up of a gas called methane.
- Geothermal is the type of energy that is steam (or hot water that has been converted to steam) that comes from deep inside the earth.
- Hydropower uses the power of falling water. Ocean energy uses the energy of the ocean’s waves and tides. Wind power uses the force of the wind to spin turbines.
- Battery electric vehicles, hybrid electric vehicles, natural gas vehicles, fuel-cell vehicles, biodiesel vehicles, and people-powered vehicles are some alternative fuel vehicles.
- Some benefits of people-powered vehicles are that they produce no pollutants and help keep the environment healthy. They also contribute to personal health with exercise, helping people avoid obesity and heart disease. Finally, people are easy to fuel—all it takes is food!