A numerical solution to the defect chemical equations was used to model the defect population in europium-doped strontium cerate (ESC) at vapor partial pressure and oxygen partial pressure range in hydrogen atmosphere. The results of the simulation compared well with the work previously reported in the literature. The numerically simulated defect concentrations were then used to predict the conductivity and hydrogen permeability of ESC membranes as a function of temperature. Uniquely, the model was then validated by comparing the predictions with experimental data for ESC membranes. The results of that exercise showed that the model is in good agreement with the experiment at temperatures high enough that the effects of defect interaction can be ignored; and where the assumption of a dilute solution of defects is valid. The agreement with the experiment further enabled the model to be used to obtain credible predictions for the ambipolar conductivity of ESC and hydrogen flux through ESC as a function of feed side hydrogen partial pressure. Copyright (C) 2012, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved.