Bus powered polymer electrolyte membrane fuel cell Ilustración e icono

Cutaway illustration of a transit bus showing an underfloor polymer electrolyte membrane fuel cell (PEMFC) powertrain. Multiple fuel cell stack modules and auxiliary balance-of-plant units are mounted longitudinally along the central chassis, delivering electric power to a traction motor located near the rear axle. In the engineering and electrochemistry domain, the fuel cell functions as an energy-conversion device that oxidizes hydrogen to produce electricity and heat for vehicle propulsion. The depiction shows hierarchy from stack components to the whole vehicle propulsion system situated within the bus frame.