Zirconia doped with scandia and ceria (10Sc1CeSZ) is presented as an electrolyte in solid oxide electrolysis cells (SOECs) for hydrogen production at intermediate temperatures. At 700 C, the conductivity of the 10Sc1CeSZ is 0.057 S cm(-1) and the ohmic resistance at OCV is 0.27 Omega cm(2). The electrolysis tests using Pt electrodes show that the oxygen ion conduction in the electrolyte produces high current densities when operating as a SOEC. The performance of cells with Ni-YSZ (yttria stabilised zirconia) cathodes are also tested under external potential load at temperatures between 600 degrees C and 900 degrees C. These preliminary results demonstrate the suitability of 10Sc1CeSZ as an electrolyte for SOECs although further work is required to develop suitable electrodes. (C) 2009 Elsevier B.V. All rights reserved.