26-05-2025
How can we harness the renewable energy off Ireland's west coast?
Analysis: A major windfarm project off Connemara has been withdrawn, but two emerging technologies could provide a solution
Ireland's Atlantic coast presents both an enormous opportunity and a formidable challenge for renewable energy development. The recent withdrawal of the Sceirde Rocks Project off Connemara, which would have been Ireland's first commercial west coast offshore wind project, tells an important story. Challenging site conditions were cited as key reasons for abandoning the €1.4 billion project. Furthermore, the prospect of 325m high turbines up to 5km from shore had drawn local criticism for the potential visual impact on the landscape in an area of immense natural beauty. The Sceirde Rocks Project was set to incorporate fixed-bottom offshore wind technology, and this setback has indicated that if we want to harness the Atlantic's energy, we may need to think differently about how to do it.
It is now unlikely that any commercial offshore renewable energy project will be developed off Ireland's western seaboard before 2030. By then, two emerging technologies could hold the answer to harnessing the energy off our west coast more effectively: floating offshore wind and wave energy. Both offer solutions to the problems that made the Sceirde Rocks Project unworkable, while better respecting the west coast's natural beauty. Here, we examine why these alternatives may be better suited to Ireland's Atlantic frontier as we look toward the 2030s and beyond.
The problem with fixed-bottom wind for Ireland's west coast
Traditional fixed-bottom offshore wind farms, where turbines are fixed directly to the seabed, are generally suited to waters with less than 80m of depth, and large swathes of Ireland's marine territory off the east and south coasts meet this criterion. This is now where all currently planned offshore wind farms are set to be developed under the government's ORESS-1 (east coast) and ORESS-2 (south coast) auctions in the coming years, which will justifiably employ fixed-bottom offshore wind technology.
From RTÉ Radio 1's Morning Ireland, How feasible are the Government's offshore wind ambitions?
The west coast however presents a different proposition geotechnically. Deeper waters necessitate placing fixed-bottom offshore wind projects closer to shore, potentially compromising the natural beauty of the visually sensitive west coast. Furthermore, the seabed close to shore off the west coast is rocky in most places, which is difficult to work with for installing offshore renewable energy infrastructure.
Floating offshore wind: A flexible alternative
Floating offshore wind turbines are mounted on buoyant platforms usually anchored to the seafloor with mooring lines, allowing them to be deployed in much deeper waters further from shore in comparison to their fixed-bottom counterparts. For the west coast of Ireland, this means avoiding the nearshore rocky areas that troubled the Sceirde Rocks project, while simultaneously reducing visual impact on the coast.
Two subsidised floating offshore windfarms are currently deployed in the UK, with Hywind Scotland and Kincardine producing power on the North Sea since 2017 and 2021 respectively. A 2021 study by UCC found that floating wind could be particularly well-suited to Ireland's Atlantic waters, yet it remains to be seen if such structures deployed off Ireland's west coast will withstand extreme wave heights in excess of 20m.
Various designs of wave energy converter have been trialled over the years. To date, none have reached commercial readiness, but expectations for 2030 and beyond are high in Europe. One concept currently leading the race is CorPower Ocean's point absorber. Deployable at depths of over 40m, it is designed to efficiently capture energy from the waves while automatically protecting itself during severe storms.
Recent tests off the coast of Portugal have been promising, with CorPower's device surviving waves of up to 18m during an Atlantic storm. Protruding less than 10m above the sea surface, these devices sit much lower in the water than offshore wind turbines, making them almost invisible from shore. Ireland has one of the best wave energy resources worldwide and CorPower have now teamed up with ESB to develop a pioneering pre-commercial wave energy farm off the coast of County Clare by 2030. In terms of cost, a 2024 study at MaREI found that the levelised cost of wave energy could become competitive with that of floating offshore wind in the 2030s, particularly in high-energy locations like Ireland's west coast.
The west coast of Ireland supports important fishing grounds, marine life and a thriving tourism industry. Here again, wave and floating wind energy technologies could provide advantages. Unconstrained by depth, farms deployed further offshore would reduce potential conflicts with coastal marine life and inshore fishing. With wave energy devices sitting low in the water, and floating wind turbines capable of being deployed further offshore, visual impact would also be mitigated along the world famous Wild Atlantic Way (which now generates over €3 billion annually for the local economy).
From RTÉ News, Study finds tourism on Wild Atlantic Way worth over €3bn a year
As with any offshore renewable energy development, both technologies could create further economic opportunities in adjacent coastal communities in the west, with the Port of Shannon-Foynes now gearing up to become an international hub for floating offshore wind and CorPower Ocean's "mobile factory" concept enabling on-site fabrication of wave energy converters close to their deployment site, fostering high local content in projects.
The withdrawal of the Sceirde Rocks project should be seen as a valuable lesson going forward. Technology selection is very much site dependant, and in general, the traditional fixed-bottom wind approach may not be the best solution for Ireland's west coast. By considering appropriate and promising emerging alternative technologies for our Atlantic region in the forthcoming National DMAP, we can develop a strategy that works with the geography of Ireland's west, rather than fighting against it.
As we look toward 2030 and beyond, Ireland has a unique opportunity to become a world leader in emerging marine energy technologies such as wave and floating offshore wind energy, and by doing so, we can harness the abundant natural power of the Atlantic securely for generations to come, while also protecting the wild natural beauty that makes the west coast of Ireland so valued.
