The physico-chemical properties of two protonic electrolytes BaCe0.8Y0.2O3-delta and BaCe0.9Y0.1O3-delta were investigated. The BaCe0.8Y0.2O3-delta electrolyte showed better crystallographic purity and lower amount of carbonate phase on the surface. A comparison between the BaCe0.8Y0.2O3-delta protonic electrolyte supported cell and an anionic (Ce0.8Gd0.2O1.95) one was made. The maximum power densities (IR-free) of 183 mW cm(-2) and 400 mW cm(-2) were obtained in H-2 (R.H. 3%) at 700 degrees C, for the protonic and anionic electrolyte based cells, respectively.