New tricks for an old power source (fuel cells)

The results of a successful Japanese effort to make fuel cells commercially viable are discussed. The three main types of fuel cell being applied to or developed for terrestrial electric-power applications are distinguished chiefly by their electrolytes: phosphoric acid; a mixture of molten lithium, sodium, and potassium carbonate; or solid zirconium oxide stabilized with yttrium oxide. A description is given of these fuel cells and how they work. The phosphoric-acid fuel cells are the farthest along in development, and some of their applications are examined. Anticipated costs are discussed.<>