A fuel cell is an electrochemical device that combines hydrogen (or hydrogen-rich) fuel and oxygen to produce electricity, heat and water. It is much cleaner and more efficient than an internal combustion engine (ICE) as it does so without burning the fuel. Essentially more of the fuel is converted into electricity and less into heat.
The active components of a fuel cell are combined in the membrane electrode assembly (MEA), which is composed of an anode, a cathode and an electrolyte membrane. Hydrogen fuel is supplied to the anode, and oxygen to the cathode, via the bipolar plates. The anode is coated with a catalyst which accelerates the conversion of hydrogen to protons and electrons. The electrolyte membrane is selective to protons only,
allowing them to pass through to the cathode. The electrons must move via an external circuit generating an electrical current and excess
heat. At the cathode the protons, electrons and oxygen combine to generate a water molecule, the only by-product of the process.
Individual fuel cells can be compiled to form stacks, which in turn can be combined into larger systems. This means that fuel cell systems vary significantly in both size and power, ranging from portable systems for transportation to large scale installations that provide electricity for high energy demand applications such as schools and hospitals.