Introduction
ESB and Parkwind are collaborating to investigate the feasibility of developing the Clogherhead Offshore Wind Farm, approximately 10km off the County Louth coast. This is the second project in this partnership, following on from the nearby Oriel Wind Farm Project.
Foreshore Licences
ESB was granted two foreshore licences, one for Clogherhead in 2018 and a second for Cooley Point in 2019, off the coast of County Louth. The granting of a foreshore licence enabled the project to undertake preliminary survey work and site investigation studies to determine suitability for an offshore wind farm and its grid connection route.
Such site investigation studies related to the cable corridor, cable landfall areas, and the indicative location of the turbine array. The results of the survey work, in conjunction with other desktop studies, and community consultation assisted in determining the feasibility of developing an offshore wind farm at this location.
The limits of the foreshore licence do not reflect the proposed extent and layout of potential wind turbines on the site but simply the limits of feasibility studies and investigative work. The location of a development site at this location will be determined by the Irish Government as part of any future Designated Maritime Area Plan (DMAP). Further details on DMAPs are outlined in the ‘DMAP Process’ section below.
Offshore Surveys
Offshore surveying of the site is integral to the potential development of the Clogherhead Offshore Wind Farm. The outputs from these surveys shape the project design for the feasibility and consenting process and ultimately inform the detailed design and construction phases of the project.
A number of offshore seabed and sub-seabed surveys are required to analyse the geological and engineering characteristics of a wind farm site and associated cable routes.
Geophysical surveys were completed within the Clogherhead and Cooley Point foreshore licence boundaries in 2022 and 2023. This included vessel-based surveys of the main offshore area in 2022 and the nearshore intertidal area in 2023. The data collected from these surveys will be used to build a comprehensive model of the seafloor and sub-seafloor environment and will be used to help determine the feasibility for the development of an offshore wind farm. This data will also inform the need for further surveys and provide preliminary input to foundation design and cable route design including the optimum installation methodologies.
A 12-month Metocean survey was carried out in 2023. This included the deployment of three Metocean data buoys across the proposed wind farm area and cable route to collect high resolution site data. Oceanographic surveys such as these are critical to the engineering design of offshore wind farms.
Environmental surveys including marine mammal surveys and ornithology surveys of the study area have been undertaken. These and other environmental surveys (e.g., benthic surveys) will be required as the project design and environmental impact assessment necessitates. These will be both vessel and aerial based surveys.
Further surveys which are necessary in the development of offshore wind farms include vessel based geotechnical investigations incorporating intrusive borehole sampling and cone penetration testing. Wind resource surveys are also required to provide wind (speed, direction), and other meteorological data (temperature, humidity, pressure). Wind resource surveying is typically conducted by means of temporary floating LiDAR moored within and/or nearby the proposed wind farm area. The outputs from these surveys are crucial to inform the wind farm engineering design, turbine selection, operational and installation parameters and to estimate the future annual energy production at the site.
The Clogherhead and Cooley point foreshore licences expired in 2023 and 2024. Any further site investigation work will be dependent on details of Designated Maritime Area Plans (DMAPs) published by the Irish Government as part of the plan-led approach to delivery of offshore wind in Ireland.
DMAP Process
In 2021, Ireland legislated for a plan-led approach to positively change the management of our sea areas. In 2023, a decision was taken by the Irish Government that the designation of maritime areas for future developments of offshore renewable energy (ORE) be determined by the State.
The South Coast Designated Maritime Area Plan (DMAP) for offshore renewable energy represents the first sub-national, forward maritime spatial plan for ORE in Ireland. The preparation of this draft Plan has taken place pursuant to the legislative provisions of the Maritime Area Planning Act, 2021 (MAP Act), and is consistent with Ireland’s National Marine Planning Framework (NMPF). The draft South Coast DMAP for offshore renewable energy is available to view on the Irish Government website here.