The basic idea behind hydrogen fuel is simple—the hydrogen gas is passed through a stack of fuel cells that combines the pure hydrogen with oxygen from the air to create water, electricity, and heat.
Web Links
Making Envronmentally-friendly Cars
This site from Toyota uses kid-friendly graphics to explain hydrogen powered cars and more.
Hydrogen-powered Cars: A simple explanation
Learn About Hydrogen Energy
NASA uses hydrogen fuel to launch the space shuttles. This website gives you more in-depth explanations about this technology.