  The low-temperature equilibrial state of a system of small metal grains,
embedded into insulator, is studied. We find, that the grains may be charged
due to the fluctuations of the surface energy of electron gas in grains, rather
than quantization of electron states. The higherst-occupied level in a grain
fluctuates within the range of order of charging energy below the overall
chemical potential. The system, called a gapless Hubbard insulator, has no
overall energy gap, while the transfer of an electron on finite distances costs
finite energy. The ionization energy is determined mostly by the intragrain
Coulomb repulsion, rather than a weak intergrain interaction, responsible for
the Coulomb gap.
  The hopping transport in the system is studied. The hopping energy is
determined by the charging energy. At low temperature the transport has gapless
character.
