  We study in detail the power of the reactor experiment kamLAND for
discriminating existing solutions to the SNP and giving accurate information on
neutrino masses and mixing angles. Assuming the expected signal corresponding
to various ``benchmark'' points in the 2 dimensional $(\Delta m^2,\tan^2
\theta)$ mixing plane, we develop a full-fledged $\chi^2$ analysis which
includes KamLAND spectrum and all the existing solar evidence. A complete
modelling of statistical and known systematics errors for 1 and 3 years of data
taking is also included, exclusion plots are presented.
  We find a much higher sensitivity especially for values of $\Delta m^2$ lying
in the central part of the LMA region. The situation would be more complicate
for values closer to the border of the LMA region (the so called HLMA region,
i.e. $\Delta m^2 \leq 2 \times 10^{5}$ and $\Delta m^2 \geq 8-9 \times 10^{-5}$
or $tan^2 \theta$ far from $\tan^2 \theta = 0.5$). In this case kamLAND, with
or without solar evidence, will be able only to select multiple regions in the
parameter space, in the sense that different possible values of the parameters
would produce the same signal.
