Rathlin Sound is an energetic tidal site between Rathlin Island and north coast of Northern Ireland, located within the North Channel.
This work presents a well validated 2D numerical model of Rathlin Sound and determines the upper limit to power extraction east of Rathlin Sound to be about 298 MW for M2 and 330 MW for M2+S2 tidal signals. This limit in power extraction is not well approximated by either the undisturbed kinetic power or the power naturally dissipated at the seabed in Rathlin Sound.
At maximum power extracted in Rathlin Sound, there is substantial reduction in mean flow speeds in the strait and south-east of Rathlin Sound, and mean differences in sea surface elevation of 10 % and 1 % are observed in the near and far field of the site. Power extraction both offshore of the island and in the strait yields higher power generation rates than isolated extraction. Resource assessments for Rathlin Sound are generally in good agreement with those for an idealised strait between an island and landmass.