Hydrogen Fuel Cells

Hydrogen Fuel Cells

Fuel cells and their ability to cleanly produce electricity from hydrogen and oxygen are what make hydrogen attractive as a "fuel" for transportation use particularly, but also as a general energy carrier for homes and other uses, and for storing and transporting otherwise intermittent renewable energy. Fuel cells function somewhat like a battery—with external fuel being supplied rather than stored electricity—to generate power by chemical reaction rather than combustion. They typically consist of numerous small cells in layers though, rather than a single large one. There are several different types of fuel cells using different catalysts (chemicals, in this case probably metals, that trigger a chemical reaction without themselves being used up by it) and electrolytes (non-metallic conductors of electrical ions, classically in a solution, but for fuel cells more likely in a solid membrane). In one type, for example, however, hydrogen fed to one catalyst-containing electrode splits to a positively charge hydrogen ion (proton) and a negatively charged electron. The positive ions travel through the electrolyte to the other catalyst electrode where they combine with oxygen fed to that electrode—and electrons—to produce water and heat. The necessary electrons are drawn through an electric circuit external to the cell, creating the electrical generation.

Source: NREL