Fuel cells are electrochemical devices that convert chemical energy into electricity at a low pollution level. Since fuel cells do not have the limitations of internal combustion engines (Carnot cycle), they can generate electricity with much higher efficiency. In addition, the progressive increase in utilizing hydrogen as a clean energy carrier has led to great interest in developing more efficient fuel cells as a prospective power source from both research and manufacturing communities. In this regard, fuel cells have already shown great potential in providing electricity for rural areas with no or limited access to the public grid, removing the huge cost of wiring and electricity transfer to these areas. As is presented in Table 14.1, when compared to common power generation systems, fuel cells provide the highest efficiency, reaching efficiencies as high as 80% when used in combined heat and power (CHP) applications.