  We investigate the formation of neutral and singly ionized scandium lines in
the solar photospheres. The research is aimed derive solar $\log
gf\epsilon_{\odot}$(Sc) values for scandium lines, which will later be used in
differential abundance analyses of metal-poor stars. Extensive statistical
equilibrium calculations were carried out for a model atom, which comprises 92
terms for \ion{Sc}{i} and 79 for \ion{Sc}{ii}. Photoionization cross-sections
are assumed to be hydrogenic. Synthetic line profiles calculated from the level
populations according to the NLTE departure coefficients were compared with the
observed solar spectral atlas. Hyperfine structure (HFS) broadening is taken
into account. The statistical equilibrium of scandium is dominated by a strong
underpopulation of \ion{Sc}{i} caused by missing strong lines. It is nearly
unaffected by the variation in interaction parameters and only marginally
sensitive to the choice of the solar atmospheric model. Abundance
determinations using the ODF model lead to a solar Sc abundance of between
$\log\epsilon_\odot = 3.07$ and 3.13, depending on the choice of $f$ values.
The long known difference between photospheric and meteoritic scandium
abundances is confirmed for the experimental $f$-values.
