ABSTRACT
This chapter begins with a brief review of fuel cells basics, how they work and why they can achieve their remarkable performance levels. It discusses each of the five types of fuel cell – phosphoric acid fuel cells, alkaline fuel cells, molten carbonate fuel cells, solid oxide fuel cells, and proton-exchange membrane fuel cells. The chapter compares fuel cell distributed generator (DG) units with other types of DG. Fuel cells are similar to batteries in that both produce a DC current by using an electrochemical process. Fuel cells convert chemical energy directly into electrical energy, being essentially batteries that are continuously “re-powered” by a chemical replacement involving fuel and air. The oxidation of hydrogen, carried out in the presence of the electrolyte, produces a charge, which will drive a direct current flow from anode to cathode. The voltage in any one fuel cell is quite low – less than 2 volts – a function of the type of electrolyte used.
