Maurice Kerr, Andrija Krivokapic and Casper Holmgaard Jensen provide a high-level overview of Ireland’s offshore wind projects and industry, while outlining the important role of ports and the key attributes and infrastructure requirements needed to support offshore wind developments. 

In November 2021, targets were set by the government in the Climate Action Plan 2021 for 80% of electricity to be generated from renewable sources by 2030, of which 5GW is to be from installed offshore wind(1). To achieve these targets, a significant number of offshore wind projects are planned around the Irish coast.

As many of the country’s existing ports are considered poorly suited to servicing the rapidly evolving needs of the offshore wind industry, a key aspect of delivering such a significant commitment to offshore wind will be the development and upgrade of port facilities to support construction, operation, and maintenance activities. In many cases, the provision of adequate facilities to support construction lie on the critical path for delivery of the development.

This article provides a high-level overview of Ireland’s offshore wind projects and industry, outlines the key roles of ports as well as key attributes and infrastructure requirements with respect to supporting offshore wind developments, reviews the general suitability of Irish ports, and outlines potential next steps for ports with regards to supporting the offshore wind industries 2030 targets. 

Industry status overview

With a maritime area more than seven times the size of Ireland’s land mass, there is enormous potential for offshore wind development in Irish waters, however, to date progress has been slow. While there are more than 40 offshore wind projects(2) in the concept or planning phase, there is only one relatively small-scale operational offshore wind farm, the Arklow Bank Wind Park Phase 1.

Commissioned in 2004, this offshore wind farm host’s seven turbines based on mono-pile foundations (bottom-fixed) with an installed capacity of 25MW. By comparison, in the waters surrounding the United Kingdom, as of January 2022 there are about 2,300 installed turbines with a capacity of more than 10,000MW(3)

Figure 1: Indicative Offshore Wind Farm Arrangement. Image: COWI

Limitations in the existing national grid electrical infrastructure and the lack of an effective maritime planning system have been flagged by the industry as key reasons for the lack of progress in Ireland, with a need for large-scale port infrastructure to support project deployment and smaller-scale port facilities to provide continuing operation and maintenance (O&M) services also identified.

However, with the unveiling of the ‘National Marine Planning Framework’ (July 2021), publication of EirGrid & SONI’s ‘Shaping our electricity future report’ (November 2021), publication of a 'Policy statement on the facilitation of offshore renewable energy by commercial ports in Ireland’ (December 2021) and passing of the Maritime Area Planning Bill 2021 through the oireachtas (December 2021), a pathway for accelerated progress is emerging.

In particular, the Maritime Areas Planning Bill 2021, which aims to develop a simpler permitting process for offshore wind projects, is likely to be a significant catalyst for development once enacted.

Additionally, EirGrid and SONI’s report suggests the technical feasibility of reinforcing and upgrading the key areas of Ireland’s electrical infrastructure to support the 2030 targets and sets out a roadmap for key developments needed to support the transition(6).

Figure 2: Map of Ireland detailing potential electrical network reinforcements. Image: EirGrid Plc, SONI Ltd 2

In general, it is planned that the 2030 target for offshore wind will primarily be achieved through development of sites off the east and southeast coasts with bottom-fixed foundation turbines on account of relatively favourable conditions and existing relatively strong onshore transmission.

A relatively small contribution to the 2030 target is anticipated from installations off the west coast. In the longer term, development of sites along the southwest and west coasts – characterised by deeper waters and less developed existing onshore transmission systems – could include the widespread deployment of floating turbines(4).

Role of ports in offshore wind development

Ports are an integral part of the offshore wind farm supply chain by virtue of their function as an interface between land based and marine activities. They play a role in all offshore wind (OW) project development stages (Figure 3) although the importance of location, demands on the quayside infrastructure, importance of the industry-relevant supply chain presence and other factors which dictate the development, greatly differ.

Figure 3: Roles of ports in OW project lifecycle. Image: COWI

When focusing on ports as enablers for OW turbine deployment (or roadblocks) it is particularly important to mention the installation phase. Ports used in the installation stage are known as staging or marshalling ports, and are required to be in relative proximity to the OW site to reduce the duration of installation (steaming distance) and optimise the use of weather windows.

This is in part driven by the high cost of leasing specialised wind turbine installation vessels (see Figure 5), which are used to shuttle and install the components.  

A staging port serves as a marshalling yard for receipt and storage of the components. In a way, it is a final station of a distributed production line where secondary components are put together into sub-assemblies and various other finishing operations are done. To minimise offshore operations, pre-assembly and pre-commissioning of components (towers and nacelles) are undertaken here as well.

From a review of the facilities used to support offshore wind farm construction at key international ports, planning and design of facilities aiming to support the offshore wind industry in future, as well as through dialogue and collaboration with offshore wind developers, COWI has identified and developed a comprehensive benchmark for such facilities. 

Figure 4: Schematic overview of the sourcing and installation process. Image: COWI

A brief overview of often critical attributes and requirements for bottom-fixed staging (marshalling) ports is listed below:

  • Based on a sample of 40 most recent projects, the median distance range between staging port and the site is 50-100km with the vast majority being less than 250km from the staging port;
  • Sufficiently deep water in the entrance, manoeuvring area and along the berths. Generally, a minimum depth of 8m from chart datum is considered appropriate although 10-12m is recommended. Air draft should be unrestricted;
  • A sufficiently wide entrance to the port to facilitate vessels and cargo adequate clearance to the port and berths. Considering the significant size of some components such as the turbine support tower, transition piece, foundation section and pieces, typically an entrance width more than 200m is appropriate, though wider is often recommended;
  • Adequate berth length, depth, and bed material to facilitate mooring, unloading, and loading of vessels. Bed material is particularly relevant as wind turbine installation vessels are to be used/deployed at berth for loading to facilitate installation of spud legs;
  • An appropriate load capacity for marine infrastructure and storage areas with regard to their proposed use within the port arrangement (eg, storage of specific elements, loading activities etc) and transport/handling arrangements (ie, self-propelled modular transporter (SPMT) or crane loading etc). Typically, bearing capacity requirements range from 5-25 tons/m2. This greatly depends on the type of berth structure and area across which the peak load can be distributed;
  • Substantial available yard area for storage and ancillary activities. In the order of 20ha is typically required to support installation of 500MW during one season.

Figure 5: Wind Turbine Installation Vessel (with legs deployed, installing mono-pile transition pieces) Image: GeoSea NV

Figure 6: Typical Bottom-Fixed and Floating Offshore Wind Platform Types. Image: COWI

In the case of floating offshore wind farms, many of the same roles and requirements as bottom-fixed offshore wind farms can also apply, however, further requirements are likely.

This could, for example, be larger yard areas or facilities for launching of the floaters, if the port is to support their fabrication. If the port is intended for integration between the floater and turbine, it could require significant water depth at berths. Requirements can greatly differ depending on the type of floater that is chosen for the project.

Due to smaller vessel sizes, O&M ports generally do not need heavy infrastructure and typically requirements are like those of commercial fishing ports.

With regards to selecting an O&M base port, the distance between the port and development is a critical factor. Typically, crew transfer vessels are used for distances up to 50km, though possibility extended to 100km with accommodation facilities on substation platform or if assisted by helicopters. 

Use of service offshore vessels allows for the base port to be located anywhere from 100 to 200km away and can be effectively located to service/maintain several offshore wind farms from one operation centre.

The focus of developers with respect to O&M ports is often primarily commercial and aimed at securing strategic long-term commitment from a port to prioritise and support O&M activities throughout the development’s service life.

As such, further important factors that influence the selection of a base port are the existence of a suitable local supply chain for services and facilities associated with maintenance (typically like those associated with small vessel shipyards and the oil and gas industry) and the availability of a qualified workforce.

O&M can account for up to 30% of an OW development’s total cost. Spread over the service life and captured by a local supply chain, these activities often present opportunities for sustained social and economic gain in coastal communities.  

Figure 7: Illustration of the multi-port strategy where floaters are fabricated in one facility (semi-sub, in this case), transported to another port for integration with turbine and towed to the site. Image: COWI

An example of an OW port prepared and used as a stagging port for both bottom-fixed and floating developments is the Port of Grenaa, Denmark.

To service the offshore industry, a new section of the port was constructed to accommodate marshalling, pre-assembly of towers, blades and nacelles and stagging activities of the precommissioned components to the OW site.

The new facilities include additional berth length to an appropriate water depth to accommodate load-out of pre-assembled turbine components onto installations vessels, sufficient hinterland for marshalling of components as well as a quayside area with increased bearing capacity to meet the requirements for loading by heavy turbine components and crane operations for load-out.

Grenaa is also used as an operation and maintenance centre for Anholt offshore wind farm. At designated areas the seabed in front of the quay was reinforced to facilitate installation of spud legs from installation vessels during load-out. COWI# is the port’s consultant and is currently planning and designing a new quay section for the offshore industry.

Figure 8: Marshalling and stagging operations for towers, blades and nacelles at the Port of Grenaa, Denmark. Image: Port of Grenaa.

Figure 9: Preassembly of tower on floating offshore wind platform. Image: The Port of Grenaa.

Another example of an OW port is the facility at Bladt Industries located in the Port of Aalborg, Denmark. The increasing demand for higher quay loading capacity for pre-assembly and stagging of bottom-fixed foundations was met by an upgrade of the port’s existing facilities (planned and designed by COWI#).

Structural upgrade of the existing quay front area was performed to accommodate heavy loading with transition pieces, monopiles and top-sided elements load-out activities.

Designated areas of the quay front were further upgraded to accommodate heavy loading during crane load-out operations and for load-out by roll-on with SPMTs. Hinterland areas were also reinforced to accommodate operations for up-ending, pre-assembly and storage of transition pieces.

Figure 10: Upgraded port facilities at Bladt Industries at the Port of Aalborg, Denmark. Preassembly and load-out of transition pieces. Image: Bladt Industries

A further example of a port which has developed to support the OW industry is Belfast Harbour. Belfast’s D1 facilities include a maintained channel depth of 9.3m, berths for vessels of up to -9.5m draught, no air restrictions and a purpose-built 50-acre offshore wind terminal, which includes a 480m heavy-duty quay (capacity up to 50T/m2) with jacking-up capability for installation vessels.

To date, Belfast Harbour has been instrumental as a staging port to support construction of the West of Duddon Sands, Walney Extension West and Burbo Bank Extension offshore wind farms.

Figure 11: Overview of OW Facilities at Belfast Harbour. Image: Belfast Harbour

Irish offshore wind farm port infrastructure

With the immediate focus of most offshore wind farms centering on the east and southeast coasts, Port of Cork, Port of Waterford, Rosslare Europort, Dublin Port, Drogheda Port and Belfast Harbour might be considered well positioned to support proposed developments in the short term.

Future developments along the west coast may in time create opportunities for further ports to support offshore wind such as Shannon Foynes Port, Castletown Bere and Killybegs.

However, each of these ports host various existing operations which limit capacity for OW activities and apart from Belfast Harbour are considered to have few berths suitable for servicing the offshore wind industry and are generally constrained by limited storage capacity.

Considering Belfast Harbour’s location, it is well suited to support developments off the east coast; though it could be challenged by demand to support several developments simultaneously, as may be required to achieve the required pace of installation, and is located relatively far from proposed developments in the lower southeast and Celtic Sea.

Figure 12: Indicative Large Diameter Mono-Pile. Image: COWI

In the case of Arklow Bank Wind Park Phase 1, Rosslare Europort was used to support construction, with components being shipped to and partly assembled in the port area before being transported and installed on site.

However, the scale of both wind farms and components has increased significantly from 2003 and is now of a size that is likely to pose a challenge in terms of quay suitability, handling and storage space to most of Ireland’s existing ports.

For instance, the seven Arklow Bank Phase 1 3MW turbines weighed about 290t, have a height of about 73.5m and a blade length of about 51m, while it is anticipated that the 62 (approx.) 8MW turbines planned for the adjacent Arklow Wind Park Phase 2 will weigh in the order of 500t, be installed at heights of up to 95m and can have a blade length in excess of 85m.

The upper range of currently available turbines which may be considered for other sites around the coast are typically in the order of 10-12 MW, weighting about 650t, are installed at heights of up to 110m and can have a blade length of more than 100m. Larger turbines may also be considered in some locations.

In 2018 the Irish Maritime Development Office published A Review of Irish Ports Offshore Renewable Energy Services (IPORES, 2018), which presents a summary of the capabilities of Irish ports to support the offshore renewable area.

The review concludes existing ports in the republic have several significant limitations to supporting offshore wind development including the availability of space and existing operations.

The review also highlighted that Belfast Harbour has established a dedicated terminal to service offshore wind projects, as well as outlining that several future development opportunities potentially exist at Port of Cork, Dublin Port, Rossaveal Harbour, Arklow and Galway Harbour(8).

A high-level ports readiness assessment of Irish ports (republic) is presented in the Carbon Trust’s report 'Harnessing our potential, investment and jobs in Ireland’s offshore wind industry' (March 2020).

The assessment also concludes that the availability of space, unfavourable physical characteristics in many cases and in some cases inadequate handling equipment poses a significant limitation. However, it is outlined that with investment, Port of Cork and Waterford Port could accommodate staging and potentially manufacturing(7).

The recently published policy statement on the facilitation of offshore renewable energy by commercial ports in Ireland elects a multi-port approach for servicing the offshore wind industry to reduce risks associated with focusing on a single port.

Reflecting on installed offshore wind targets, the policy statement outlines that a minimum of two large-scale facilities will be required from 2025 to support developments and multiple smaller ports will be needed for operation and maintenance activities(4).

There are several potential future port developments that are currently being explored, many with a view to servicing the installation stage of offshore wind developments (or could be adapted for this purpose). These include:

  • ESB’s repurposing of Moneypoint Power Station;
  • Expansion of Shannon Foynes Port;
  • Development of a new port at Bremore by Drogheda Port Company in partnership with Ronan Group Real Estate;
  • Further OW terminal facilities (D3 development) in Belfast Harbour;
  • Deep-water quay development at Rossaveal Harbour;
  • Port of Galway’s proposed redevelopment;
  • Redevelopment of Cork docklands by Doyle Shipping Group;
  • Expansion of Rosslare Europort as well as Dutch logistics company XELLZ’s planned offshore wind supply base adjacent to the port; and,
  • Renewable energy construction facility at Greenore Port proposed by Doyle Shipping Group.

Recent large-scale port projects in Ireland such as Port of Cork’s Ringaskiddy container terminal and Dublin Port’s ocean pier berth 35 redevelopment have required a duration of five years from grant of planning to commencement of operations. Albeit both projects were delayed in part by unforeseen circumstances, an aspiration for two new large-scale facilities by 2025 is, nevertheless, considered ambitious and would place port developments to support offshore wind firmly on the critical path to facilitating offshore wind construction.

Potential next steps for Irish ports

As several Irish ports are in the process of exploring how they can service the offshore wind industry, the route forward for individual ports will vary. However, a list of potential next steps for consideration by ports (as well as other supply chain stakeholders) to facilitate the technical assessments of port suitability for supporting the industry and develop plans for future developments is provided below:   

  1. In conjunction with developer consultations, assess in detail the suitability of existing and planned port infrastructure and general port attributes with respect to supporting bottom-fixed and/or floating development requirements (ie, planning, manufacturing, procurement, installation, operational, maintenance and decommissioning phases). As the industry is rapidly evolving, it is possible if not likely that previous assessments undertaken in recent years are no longer valid with respect to state-of-the-art development requirements. A focus of the review should also be to identify inadequacies which could be considered for upgrades or addressed through future port development.
  2. Review the feasibility of upgrading, expanding or repurposing existing facilities with a view to servicing some or all offshore wind development construction and operational/maintenance phases. The review could also consider spatial constraints and also assess the feasibility of expanding the port area on a temporary or permanent basis. The upgrade of existing facilities, depending on the scale and nature, is likely to offer a faster route to developing operational support facilities than greenfield development.
  3. Where upgrades, expansions or repurposing is identified as an appropriate option, consideration should be afforded towards developing multi-purpose facilities to maximise the potential use of new port facilities with respect to support activities within the offshore renewable energy sector, such as tidal and wave energy developments, as well as expanding existing port functions. A multipurpose approach that is compatible with other cargo operations will increase the value and sustainability of new port facilities and avoid a 'boom and bust' development cycle.
  4. Within a wider review of how a port might support offshore wind developments, consider the installation of temporary facilities and/or the long-term deployment of marine working platforms (such as flat top or jack-up barges) as a means by which existing waterfront facilities can be quickly expanded (albeit of limited extent) to support specific construction phases.
  5. Assess existing operations at ports with a view to determining whether altering existing operations may afford an opportunity for ports to cater for some support activities and capacity to service the offshore wind industry. Accommodating support activities alongside altered existing operations could be an efficient and effective solution for smaller scale phased developments.
  6. Assist with building an appropriate supply chain at the port. Offshore wind related activities draw on an entire ecosystem of associated manufacturing, logistic, cranage, vessel support and other businesses. Attracting and growing complementary services at the port helps in sustained activity and enables new opportunities.
  7. Close collaboration with developers, statutory authorities, existing operators and all other relevant stakeholders (including other ports, consultants, contractors and supply chain parties) with regards to taking forward viable upgrades and port developments through to the planning and design stages, and beyond in an expedient manner. 

Commercial viability is also of critical importance and potential upgrades, expansions and repurposing should be carefully assessed. At an EU level, funding mechanisms are in place to support energy and transport infrastructure development, such as the European Climate, Infrastructure and Environment Executive Agency’s ‘Connecting Europe Facility’.

Additionally, financing opportunities could potentially arise in future through the European Investment Bank, the Ireland Strategic Investment Fund, Green Funds or other sources.

However, to achieve the accelerated pace required by the industry to support offshore wind developments from 2025, the funding of initial studies, investigations and planning/design work may need to be invested directly by individual ports, developers, and other supply chain parties. Commercial support from government at a local or national level could also be beneficial towards achieving targets.


Ports play an integral role in offshore wind farm development, however, most of Ireland’s ports (particularly those in the republic) are currently considered to be not well suited to service the offshore wind industry.

Recent legislative advancements and the setting out of a potential roadmap to achieve 2030 renewable electricity generation targets will, no doubt, accelerate the pace of offshore wind farm project development in Irish waters.

The establishment of adequate port facilities is on the critical path to facilitating unimpeded offshore wind development. Without adequate port facilities, an opportunity to develop a robust and indigenous supply chain for the offshore wind industry could be lost to overseas ports. As such, ports, developers, and the government will need to act quickly to identify, plan, design and implement port upgrades to avoid missing the boat.

Authors: Maurice Kerr, BEng (hon) MSc CEng MIEI MICE, associate (maritime) with COWI’s Energy Practice (; Andrija Krivokapic, MSc, head of section of COWI’s terminals team (; Casper Holmgaard Jensen, MSc, at COWI within the port construction field (

(COWI is an international consulting group, specialising in engineering, environmental science, and economics. It has assisted private and public clients with the review and assessment of port facilities to support offshore wind developments in countries including Denmark, Norway, United States, Japan, Korea, Turkey and Greece. It has also worked closely with offshore wind farm developers. It ha salso assisted clients with the achievement of development, efficiency, sustainability, and environmental goals in the Port of Oslo, Copenhagen Malmo Port, Port of Frederikshavn, Port of Skagen, and Port of Esbjerg to name a few. COWI has also been appointed as owner's engineer to develop the world's first energy island in the Danish North Sea.) 


1.) Department of the Environment, Climate and Communications (2021), Climate Action Plan 2021, published on the 4 November 2021, accessible at

2.) 4C Offshore (2021), viewed at on December 28, 2021.

3.) RenewableUK (2021), Wind Energy Statistics, viewed at on December 28, 2021.

4.) Department of Transport (2021), Policy Statement on the facilitation of Offshore Renewable Energy by Commercial Ports in Ireland, published on December 20, 2021, accessible at

5.) Department of Transport (2013), National Ports Policy, last published on July 8, 2019, accessible at

6.) EirGrid & SONI (2021), Shaping our electricity future A roadmap to achieve our renewable ambition, published in November 2021, accessible at

7.) Carbon Trust (2020), Harnessing our potential investment and jobs in Irelands offshore wind industry, published in March 2020, accessible at

8.) Irish Maritime Development Office (2018), IPORES 2018 A Review of Irish Ports Offshore Renewable Energy Services, accessible at