Fuel Cells Fuel cells convert hydrogen into electricity through a process of electrochemical oxidation. The hydrogen sources for most fuel cells in operation today are fossil fuels, such as natural gas or methanol. However, fuel cells can run on renewable fuel. Hydrogen can be produced from renewable biomass sources through gasification or anaerobic digestion . In a fuel cell, hydrogen is fed continuously to the negative electrode, while an oxidant such as oxygen or air is fed continuously to the positive electrode.
Electrochemical reactions produce an electric current in a manner similar to a battery.
Four types of fuel cell are now in the early stages of commercialization. These fuel cell technologies could expand the use of renewable sources in the production of electricity. Phosphoric acid fuel cell Phosphoric acid fuel cell systems of up to 11 megawatts have been tested. This type of fuel cell operates at about 200 C and requires an external fuel processor that reforms fuels such as natural gas or methane into hydrogen. The electric generation efficiency of phosphoric acid fuel cells is 40 to 45 percent.