Theoretical and experimental aspects of a two-step short cycle,based on ZnO and CdO intended for storage of solar energy

In the present paper, chemical and energetical considerations about hybrid thermal electrochemical cycles based on zinc and cadmium oxides are developed. Intermediate reactions have been taken into account. Numerical data obtained from decomposition experiments of the oxides in a solar furnace and from electrolysis experiments with Zn and Cd metals (or metal-oxide mixtures) used as an anode, are discussed. The energy balance for the hydrogen production using the mentioned cycles is compared with a direct electrolytic water-splitting process working with thermopiles or photopiles solar plants as electricity source.