Photos: Fujitsu unveils king-size fuel cell

Ever wonder how a hydrogen fuel cell works? This poster explains the process. In a nutshell, natural gas (methane, made from carbon and hydrogen) is heated with steam until it cracks. Hydrogen is harvested and then piped to a different unit with a membrane. The membrane harvests electrons from the hydrogen molecules. Carbon dioxide and water are the byproducts. The hot water from the reaction can be used to heat buildings.