Ørsted and ESB joint venture secures the provisional rights to develop the Tonn Nua site in Irish offshore wind auction

26.11.2025 14:15:00 CET | Ørsted A/S | Investor News

Today, the Irish Department of Climate, Energy and the Environment has provisionally awarded the joint venture, formed by ESB and Ørsted, the rights to develop the Tonn Nua site which is off the coast of County Waterford and spans 306 km2.

Tonn Nua has been designated by the Irish government as the only site for bidders under the Offshore Renewable Electricity Support Scheme (ORESS) Tonn Nua, Ireland’s second offshore wind auction. The auction offers a partially indexed 20-year contract for difference (CfD), and the right to apply for a seabed lease and grid connection for the winning bidder. The contract for difference is to support the development of a 900 MW fixed-bottom offshore wind farm for the Tonn Nua site.

The Tonn Nua site is in an early phase of development. The project now needs to be assessed, matured and successfully pass all gates in the JV’s stage-gate process, including meeting the value creation criteria. Final investment decision is expected around 2031 and first power in the mid-2030s.

Alana Kühne, Head of Region Europe Development at Ørsted, said:
“We commend the Irish government for running a successful auction continuing the support for the development of offshore wind in Ireland. Offshore wind will play an important part in the future Irish energy system ensuring green, affordable and secure energy. We will continue to work with our joint venture partner ESB to carefully assess and progress this early-stage development opportunity, including ensuring that the project lives up to our value creation criteria.”

Jim Dollard, Executive Director for Generation & Trading at ESB, commented:
“ESB is delighted with the outcome of the ORESS Tonn Nua auction. It secures a clear pathway for the development of a significant project off the coast of County Waterford marking another important step toward Ireland’s renewable energy and Net Zero ambitions. We look forward to working with our partners to deliver a project that provides significant energy security and price certainty for Irish consumers.”

The Tonn Nua project 
The awarded project is for a fixed-bottom offshore wind development at the Tonn Nua maritime site, located off the coast of County Waterford.  

ORESS Tonn Nua is Ireland’s second support regime for offshore renewable energy development, and the first offshore wind auction under the new state-led planning regime.  

The next step for the project is to seek a Maritime Area Consent and Marine Usage Licence from the Irish Maritime Area Regulatory Authority in order to commence surveying and assessment ahead of submitting a planning application for the development.

About the CfD
The two-way CfD has been awarded at a strike price of EUR 98.719 per MWh. The partially indexed CfD will run for 20 years from wind farm commissioning expected in the mid-2030s.  

Ireland’s transmission system operator (TSO) EirGrid will build the transmission assets (offshore and onshore substations and export cables). The Tonn Nua Offshore Wind Farm must be operational by the longstop date of 1 January 2037 under the CfD terms and conditions.

About the joint venture
The joint venture is jointly owned by ESB and Ørsted. In 2023, ESB and Ørsted entered a 50/50 partnership to jointly develop a pipeline of offshore wind projects off the Irish coast. Tonn Nua is the first offshore wind development site progressed to auction under the partnership.

For further information, please contact:

Ørsted Global Media Relations 
Kathrine Westermann 
+45 99 55 57 21 
kawes@orsted.com 
 
SarahThatt-Foley 
+353 (0)83 156 5690 
sarfo@orsted.com 
 
Ørsted Investor Relations 
Valdemar Hoegh Andersen 
+45 99 55 56 71 
Ir@orsted.com

ESB media contact 
Aoiffe Llewellyn
aoiffe.llewellyn@esb.ie

About Ørsted 
Ørstedis a global leader in developing, constructing, andoperatingoffshore wind farms, with a core focus on Europe. Backed by more than 30 years of experience in offshore wind, Ørsted has 10.2 GW of installed offshore capacity and 8.1 GW under construction. Ørsted’s total installed renewable energy capacity spanning Europe, Asia Pacific, and North America exceeds 18 GW across a portfolio that also includes onshore wind, solar power, energy storage, bioenergy plants, and energy trading. Widely recognised as a global sustainability leader, Ørsted is guided by its vision of a world that runs entirely on green energy. Headquartered in Denmark, Ørsted employs approximately 8,000 people. Ørsted's shares are listed on Nasdaq Copenhagen (Orsted). In 2024, the group's operating profit excluding new partnerships and cancellation fees was DKK 24.8 billion (EUR 3.3 billion). Visitorsted.comor follow us onLinkedInandInstagram.

About ESB 
ESB wasestablishedin 1927 as a statutory body under the Electricity (Supply) Act, 1927. With a holding of 97.1%, ESB is majority owned by the Irish Government. The remaining 2.9% is held by the trustees of an Employee Share Ownership Plan. As a strong, diversified utility, ESB operates across the electricity market, from generation through transmission and distribution, tosupply ofcustomers, in addition to using our networks to carryfibrefor telecommunications. ESB is the leading Irish utility with a regulated asset base of approximately €14 billion (comprising ESB Networks €11 billion and NIE Networks €3 billion), a 25% share of generation in the all-island market, and retail businesses supplying electricity and gas to almost 1.9 million customer accounts throughout the island of Ireland and Great Britain. During the year ended 31 December 2024, ESB Group employed an average of almost 9,600 people.

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• Ørsted and ESB joint venture secures the provisional rights to develop the Tonn Nua site in Irish offshore wind auction.pdf