The dynamics of excess electrons in water is of fundamental importance for charge transfer and solvation processes in chemistry and biology. We have studied the ultrafast dynamics of photoinjected electrons into thin layers of amorphous ice grown on metal surfaces (Cu(111) and Ru(0001)) and probe the subsequent electron localization, solvation and transfer processes by femtosecond time- and angle-resolved photoemission spectroscopy.@footnote 1@ The solvation dynamics is observed directly through a transient increase of the electron binding energy, which occurs on a 100 fs to 1 ps time-scale and depends critically on the structure of the ice. On the other hand, exceptionally long-lived and highly localized electrons are formed in crystalline ice. As the structure of the solvent can be modified in a controlled way by the growth conditions and substrate our approach provides insights on the relation between structure and solvation dynamics in low dimensional systems. We have also used vibrational sum-frequency generation (SFG) spectroscopy, isotope scrambling experiments and work function measurements to investigate the structure of D@sub 2@O on Ru(0001).@footnote 2@ Our results suggest that the first bilayer consists of intact water molecules, while density functional theory predicts a half-dissociated structure as energetically most favourable state.@footnote 3@ Some explanations for these controversial findings will be discussed. @FootnoteText@ @footnote 1@C. Gahl et. al, Phys. Rev. Lett. 89, 107402 (2002); U. Bovensiepen et al., J. Phys. Chem. B 107, 8706 (2003); Israel. J. Chem. (in press)@footnote 2@D.N. Denzler et al, Chem. Phys. Lett. 376, 618 (2003).@footnote 3@P.J. Feibelman, Science 295, 99 (2002).