Tonn Nua
Tonn Nua ('New Wave') is a 900 MW fixed-bottom offshore wind farm off the coast of County Waterford, Ireland.
Status
Advanced Developmentlifecycle stage
ExpectedHafrok completion outlook
Ownership
HHHelvic Head Offshore Wind DAC — 100% ◆
Location
IrelandCeltic Sea
Technology
Capacity
900 MW ◆
Turbines
—
Foundation
Monopile ◆
Site & conditions
Site rights
Seabed rights held ∴
Origination
ORESS 2.1 (Tonn Nua, south coast) · 2025 ·
Water depth
48–69 m ◆
Distance from shore
12.2 km ◆
Wind speed
10.1 m/s @ 150 m ≈
Revenue & grid
Offtake
CfD · €98.719/MWh ◆
Grid
No agreement ◆
Connection
EirGrid developing offshore transmission infrastructure under … ◆
Schedule
FID
Not taken
COD · announced
2035 ◇
COD · Hafrok
2035 expected
Delivery outlook modelled by Hafrok · calibrated on delivered projects
2035
expected year of commercial operation
Chance of delivery
≈83%
estimated chance this project reaches commercial operation
Advanced Development projects complete ≈75% of the time on Hafrok's record. A secured offtake contract puts this one well above that; a market with a thinner delivery record, its size and technical complexity weigh only slightly against it.
COD outlook
If it completes, when — Hafrok’s probability by year (teal) · the developer’s COD guidance, by date stated (ink)
| Year | Probability |
|---|---|
| 2034 | 3.9% |
| 2035 (expected) | 50.2% |
| 2036 | 29.5% |
| 2037 | 10.6% |
| 2038 | 3.8% |
| 2039 | 1.4% |
| 2040 | 0.6% |
| Stated | Announced COD |
|---|---|
| 2026-06-16 | 2035 (held since 2026-04-15, 2 statements) |
How Hafrok got this date
1
Starting point: the last dated milestone
Consent granted in
2026. From there Hafrok adds how long similar projects (in developing offshore-wind markets) took to reach commercial operation, measured on projects that have delivered.2
Typical timing
Starting point plus the typical remaining time gives a middle estimate of
2031; the faster quarter of similar projects would be done by 2029, the slower quarter not until 2031.3
Result
Expected commercial operation
2035, likely range 2029–2031 (the middle half of outcomes for similar projects). The developer's announced date falls inside that likely range, so the announced date is adopted.4
Year-by-year chart
The bars spread that estimate across years using how similar projects actually slipped against their dates — more often late than early, which is why the bars lean right.
5
Chance of delivery — separate from timing
Start from the share of Advanced Development projects that went on to complete — ≈75%, measured on Hafrok's record of delivered and abandoned projects, with an allowance held back where that record cannot yet speak (projects still unresolved, changed market conditions). Consented projects have historically completed at very high rates, but the 2023–25 downturn showed consented-but-unfinanced projects can still fail — the estimate holds back for the offtake and financing gates still ahead. Then adjust for this project's own evidence — offtake, market, size, technical complexity — to ≈83%, which rates it
Expected on Hafrok's four-step delivery scale (Delivering · Expected · Prospective · Fragile).Project timeline & ownership verified milestones on the spine · ownership from Hafrok’s transactions record
Origination · 2025-12
ORESS 2.1 (Tonn Nua, south coast)
- Awarded to
- Helvick Head Offshore Wind DAC (ESB + Ørsted)
- Basis
- integrated tender
From the auction results — the round that created the project.
JV formation · 2023-06
Ørsted · ESB stake not disclosed
- Stake
- not disclosed
- Consideration
- not disclosed
- Announced
- 2023-06
- Project stage
- early development
Ørsted (Ørsted) and ESB (Electricity Supply Board) announced a 50/50 offshore wind development partnership in Ireland on 2 June 2023. The JV covers a pipeline of sites off Ireland's south and southeast coast (off counties Waterford and Wexford), targeting up to 5 GW in total. The first project, Tonn Nua (900 MW fixed-bottom), was entered into Ireland's ORESS 2.1 auction and was provisionally awarded a 20-year CfD at a strike price of €98.72/MWh, announced 26 November 2025. This record captures the JV formation event (June 2023) — the project was at very early development stage at that time with no Maritime Area Consent (MAC) yet in place. Deal value undisclosed; the agreement covers a multi-project pipeline rather than a single asset transaction. Ørsted contributed its global offshore wind development expertise; ESB contributed knowledge of Irish grid and energy markets. Final investment decision is targeted for ~2031; first power mid-2030s.
Evidence
- orsted.com — ESB and Ørsted enter partnership in landmark Irish offshore wind agreement ↗ 2023-06 ◆ held
- offshoreWIND.biz — Ørsted-ESB Joint Venture Wins 900 MW Irish Offshore Wind Tender ↗ 2023-06 ◆ held
- esb.ie — ESB and Ørsted Joint Venture wins the provisional rights to develop the Tonn Nua site in offshore wind auction ↗ 2023-06 ◆ held
From Hafrok’s transactions record
Dashed tick marks today (9 Sep 2026). The ▲ below the spine is the developer-announced COD. The teal diamond on the spine is origination — the seabed award or round that created the project. Every other ownership event lives in the band below: one station per recorded deal, dated at its label, in deal order rather than to calendar scale. Secondary trades appear only at the interchanges; grey lines are parties whose entry or exit Hafrok’s record does not hold.
Announced COD: held (announced 2035, unchanged) · the full guidance history is in the delivery chart above
Revenue & offtake contract duration and price levels · money of the day
900 MW contracted — tender award
● Tender award · ORESS 2.1 (Tonn Nua, south coast)
Price€98.719/MWh ·Capacity900 MWAwardedDec 2025Term20 yrs
Installation how the build is going · from satellite counts and Hafrok’s registers
Installation not started
nothing to count yet: the satellite tracker begins when offshore construction does
Installation · on record
StageAdvanced Development
Offshore constructionnot started
Expected start of operation2035
Construction ports
PortRosslare Europort ◇·quay 570 m · draft 12 m
Sources & verification
10/15 fields verified · rests on 10 sources (6 primary) · ◆ 6 documents held
◆Verified≈Modelled◇Sourced∴Inferred⌁Convention○Unverified∅No source·Derived
Numbers are stable citation ids — grouped by source class, so they are not consecutive.
Regulator3
[1]
Government of Ireland — Department of Climate, Energy and the Environment2025-12-09◆ ORESS 2.1 Tonn Nua result
“Helvick Head Offshore Wind DAC, a joint venture partnership between ESB and Denmark-based renewable energy developer Ørsted, has been selected as the developer for Tonn Nua. The project will have a ta…”
supportsTotal capacityWater depthDistance from shore
[2]
Government of Ireland — Department of Climate, Energy and the Environment2026-05-28◆ ORESS Tonn Nua Offshore Wind Auction
“Helvic Head Offshore Wind DAC is now confirmed as the auction winner with an offer price of €98.719 per megawatt hour. Helvic Head is a joint venture partnership between ESB and Denmark-based renewabl…”
supportsownerConsentTotal capacityMechanismStrike / price+1 more
[3]
Government of Ireland — Department of Climate, Energy and the Environment2024-10-24◆ The South Coast Designated Maritime Area…
“The South Coast Designated Maritime Area Plan for Offshore Renewable Energy was made by the Minister for the Environment, Climate and Communications on 24 October 2024, following the approval of both …”
supportsFoundation
Operator3
[4]
EirGrid2025-11-26
“Helvick Head Offshore Wind DAC, a joint venture partnership between ESB and Denmark-based renewable energy developer Ørsted, has been selected as the developer for Tonn Nua, Ireland's second offshore …”
supportsBackground
[5]
EirGrid2026-03◆ Offshore Energy Future | Projects | EirG…
“Tonn Nua represents the first Area being connected into the grid within the larger Powering Up Offshore – South Coast Programme. The infrastructure will include two offshore substation platforms to be…”
supportsStatusConnection point
[6]
ESB2023-06-02
“Ørsted becomes a 50/50 partner in a pipeline of offshore wind development projects off the Irish coast.”
supports↳ parent
Auction results1
[10]
Philip Lee LLP2026-06-22◆ ie-oress-2-1-tonn-nua-2025-tonnnua-tc
ORESS Tonn Nua T&C: escalating Performance Security EUR 80m/100m/120m; Longstop 1 Jan 2037
supportsTender award · ORESS 2.1 (Tonn Nua, south coast)
Trade press3
[7]
offshoreWIND.biz2025-11-26◆ Ørsted-ESB Joint Venture Wins 900 MW Iri…
Press report — cited, not quoted; read it at the source link.
supportsCommercial operationCOD historyTotal capacityFoundationport
[8]
4C Offshore2026
Press report — cited, not quoted; read it at the source link.
supportsCoordinates
[9]