  Geomagnetically induced currents (GICs) are a well-known terrestrial space
weather hazard. They occur in power transmission networks and are known to have
adverse effects in both high and mid-latitude countries. Here, we study GICs in
the Irish power transmission network (geomagnetic latitude 54.7--58.5$^{\circ}$
N) during five geomagnetic storms (06-07 March 2016, 20-21 December 2015, 17-18
March 2015, 29-31 October 2003 and 13-14 March 1989). We simulate electric
fields using a plane wave method together with two ground resistivity models,
one of which is derived from magnetotelluric measurements (MT model). We then
calculate GICs in the 220, 275 and 400~kV transmission network. During the
largest of the storm periods studied, the peak electric field was calculated to
be as large as 3.8~V~km\textsuperscript{-1}, with associated GICs of up to 23~A
using our MT model. Using our homogenous resistivity model, those peak values
were 1.46~V~km\textsuperscript{-1} and 25.8~A. We find that three 400 and
275~kV substations are the most likely locations for the Irish transformers to
experience large GICs.
