First survey phase finished for offshore wind development along Ireland’s south coast
EirGrid has taken a major step towards Ireland’s offshore wind future with the completion of the first phase of marine and coastal surveys along the south coast. These early insights – drawn from both completed and upcoming survey activities – will guide the development of the transmission infrastructure needed to bring offshore wind energy ashore.
Following the approval of the Maritime Usage Licence (MUL) of EirGrid – the operator and developer of Ireland’s electricity grid – by the Maritime Area Regulatory Authority (MARA), survey operations began in July 2025. The initial programme covered extensive geophysical, environmental and metocean investigations across potential cable route corridor options from Maritime Area A, or Tonn Nua, within the Irish Government’s South Coast Designated Maritime Area Plan (SC-DMAP). It also included non-intrusive intertidal landfall studies, combining geophysical and environmental assessments.
Geophysical and UXO surveys
The collected data will now be evaluated, with additional geophysical, geotechnical and unexploded ordnance (UXO) surveys scheduled for 2026. Fugro is leading the campaign under EirGrid’s Offshore Marine Survey Framework, supported by TechWorks Marine and Green Rebel, who are overseeing the metocean and environmental components.
Two MetOcean buoys, recently deployed as part of the programme, will remain in position until late 2026. They will continue to gather detailed marine and weather measurements – including waves, water quality, wind and sunlight – to inform offshore planning and environmental monitoring.
The insights gained from the 2025 and subsequent 2026 surveys will be essential to guide how EirGrid progress the project in a way that respects the local marine ecosystem and environment.
Huge amount of coordination
Over the course of the 2025 campaign, 3,770 kilometres of seabed were surveyed, involving 40,000+ man hours and huge collaboration between stakeholders across fisheries, industry and local communities.
Speaking about the 2025 survey campaign, chief transformation, technology and offshore officer at EirGrid Liam Ryan said: “These surveys would not be possible without a huge amount of coordination and strategic planning of staff across EirGrid, our strategic partners, fishing communities and local landowners. We would like to thank fisheries and local communities for their continued collaboration with us to facilitate these works.
“The data being gathered from this research is essential in shaping plans for the installation of this transmission infrastructure for offshore wind and creating a cleaner energy future for Ireland by helping to inform our optioneering processes, technical and design elements and build on our understanding of the environment in the vicinity of our potential offshore cable routes and offshore substation locations.”
Powering Up Offshore – South Coast is set to deliver the transmission backbone that will bring 900MW of offshore wind power ashore along Ireland’s south coast. The project supports the government’s climate action plan by strengthening the grid for an energy system targeting 80% renewables – including at least 5GW of offshore wind – and paving the way for Ireland’s next phase of clean-energy growth.
