Power and Heat Generation in the Heart of the Fuel Cell, the Stack.

The heart of the fuel cell is a part called the stack, which plays the part of the generator.

Structure of the Stack and Electricity Generation

The stack consists of a collection of cells, with each cell consisting of an MEA (the power generating structure) sandwiched between separators.

The separators that make up each cell are molded with channels through which oxygen (air) and hydrogen (hydrogen-rich gas) flow, supplying hydrogen and oxygen to the air electrode and fuel electrode of the MEA, which causes the electrical change and generates electricity.
Furthermore, the capacity that can be generated in one cell is limited, so the generation capacity (rating) is decided by the number of cells.

Use of Heat Generated in the Heat Exchanger

At the same time that electricity is generated, at the stage when hydrogen ions, electrons and oxygen are combined, heat is given off. Rather than dissipating this heat as exhaust heat, water in the hot water tank is heated using a heat exchanger, and can be stored in the tank at a temperature above 60°C.