A fuel cell is an electrochemical energy converter that converts chemical energy of fuel directly into direct current (DC) electricity. Typically, a process of electricity generation from fuels involves several energy conversion steps:
1. Combustion of fuel converts chemical energy of fuel into heat.
2. This heat is then used to boil water and generate steam.
3. Steam is used to run a turbine in a process that converts thermal energy into mechanical energy.
4. Finally, mechanical energy is used to run a generator that generates electricity.
A fuel cell circumvents all these processes and generates electricity in a single step without involving any moving parts (Figure 1-1). It is this simplicity that ...