  We study the ability of a quantum channel to generate quantum coherence when
it applies to incoherent states. We define the measure of coherence generating
power (CGP) for a generic quantum channel to be the average coherence generated
by the quantum channel acting on a uniform ensemble of incoherent states based
on the skew information-based coherence measure. We present explicitly the
analytical formulae of the CGP for any arbitrary finite dimensional unitary
channels. We derive the mean value of the CGP over the unitary groups and
investigate the typicality of the normalized CGP. Furthermore, we give an upper
bound of the CGP for the convex combinations of unitary channels. Detailed
examples are provided to calculate exactly the values of the CGP for the
unitary channels related to specific quantum gates and for some qubit channels.
