Input energy to mechano-catalytic water-splitting system is transferred pal-try to organize the frictional electric condenser (FEC) system, which motivates the water-splitting, acid partly to rotate the slurry. A part of the rotational energy is regained as a feedback, while the remainder is wasted to the dispersion loss through the viscous motion. The mechanism of the cyclic transfer of charge between the stirrer (Teflon), the vessel wall (Pyrex glass) and the semiconductor particles (NiO, etc.) is discussed. System efficiency, dynamic efficiency, energy conversions and the dispersion processes are analyzed. System design of the cell and the stability of FEC system are discussed as well. (C) 2000 International Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.