This second edition gives advanced undergraduate and beginning level graduate students an important introduction to the basic science and engineering behind fuel cell technology. Emphasizing the foundational scientific principles that apply to any fuel cell type or technology, the text provides straightforward descriptions of how fuel cells work, why they offer the potential for high efficiency, and how their unique advantages can best be used. Designed to be accessible to fuel cell beginners, the text is suitable for any engineering or science major with a background in calculus, basic physics, and elementary thermodynamics. Further enhancing this new edition are updated and improved examples, problems, and pedagogy for classroom use.