  We present the results of approximately three years of observations of Planck
Sunyaev-Zeldovich (SZ) sources with telescopes at the Canary Islands
observatories as part of the general optical follow-up programme undertaken by
the Planck collaboration. In total, 78 SZ sources are discussed. Deep-imaging
observations were obtained for most of these sources; spectroscopic
observations in either in long-slit or multi-object modes were obtained for
many. We effectively used 37.5 clear nights. We found optical counterparts for
73 of the 78 candidates. This sample includes 53 spectroscopic redshift
determinations, 20 of them obtained with a multi-object spectroscopic mode. The
sample contains new redshifts for 27 Planck clusters that were not included in
the first Planck SZ source catalogue (PSZ1).
