On the basis of the thermodynamic analysis of most representative recent data on hydrogen storage in graphite and novel carbon-based nanomaterials of s p(2) hybridization, the open questions have been studied of the nature, capability and reversibility of such storage, particularly, for mobile power units. For an interpretation of the thermodynamic and kinetic (diffusion) characteristics obtained in such a way, the known results have been used of 'ab initio' molecular orbital study of adsorption of atomic hydrogen on graphite and carbon nanostructures. (C) 2003 International Association for Hydrogen Energy. Published by Elsevier Ltd. All rights reserved.