Hornsea 1 OFTO
OperationalOffshore GridGB1,218 MW220 kV355 km2018
Basic information
9 fieldsAlso Known As
Hornsea One OFTO · Hornsea Project One OFTO · Diamond Transmission Partners Hornsea One OFTO · Hornsea One Offshore Transmission Owner · TR6 Hornsea One OFTO · Hornsea Offshore Wind Farm Transmission Assets
Status
operational
Capacity
1,218 MW
Owners
Project Company
Type
offshore grid
Transmission Model
Developer Build & Transfer
Expected Life
25 years
Supply Chain (9)
Project Timeline (24)
1 Mar 2021Regulatory Other
Ofgem issued its final Cost Assessment decision for the Hornsea Project One offshore transmission assets, confirming the Final Transfer Value at £1,175 million as the assessed cost base for the transmission assets that will be transferred to the successful OFTO licensee.
8 Feb 2021Stake Transaction
Ofgem granted an offshore transmission licence to Diamond Transmission Partners Hornsea One Limited (a Mitsubishi Corporation / Chubu Electric Power consortium) for the Hornsea One transmission assets. The final transfer value was GBP 1,175 million for a 25-year licence. The assets transferred from Orsted to the OFTO under Ofgem's competitive tender process.
Diamond Transmission Partners acquired from Ørsted (100%)
7 Jan 2021Regulatory Other
Ofgem published the Draft Cost Assessment for the Hornsea Project One offshore transmission assets, establishing a Final Transfer Value of £1,175 million to be used by the Authority in determining the value of the transmission assets to be transferred to the successful OFTO bidder.
2020Commercial Operations Full Power
The HOW01 (Hornsea Project One) offshore transmission assets, including three offshore substations, a reactive compensation station, three 220 kV export cable circuits and an onshore substation with two 400 kV connections to National Grid’s Killingholme substation, were expected to reach full power in Autumn 2019 and to become fully operational in early 2020, marking the start of full commercial operation of the transmission system.
11 Nov 2020Regulatory Other
Grant Thornton UK LLP completed and delivered an Ex-Ante Cost Review of the Hornsea Offshore Wind Farm Transmission Assets (HOW01) for Ofgem, summarising the developer’s projected transmission asset costs, including interest during construction, with total costs presented at approximately 1.35 billion in the report’s executive summary table.
12 Apr 2019Procurement Notice
Authority: Ofgem · Licence: Shortlisting of bidders for Hornsea Project One OFTO in Offshore Transmission Owner Tender Round 6
On 12 April 2019 Ofgem announced that five bidder consortia had been shortlisted for Tender Round 6 to own and operate three offshore transmission links, including the Hornsea Project One transmission assets, allowing these bidders to proceed to the final Invitation to Tender stage for the Hornsea 1 OFTO link.
Q4 2018First Power
In the Hornsea Project One construction schedule presented to Ofgem, energisation of the offshore transmission system was planned for the fourth quarter of 2018, marking the point at which the Hornsea 1 OFTO export system—linking the three offshore substations through the reactive compensation station to the onshore substation at Killingholme—would first be energised and able to transmit power towards the GB grid.
11 Dec 2018Cable Installation Complete
On 11 December 2018, Ørsted announced that manufacture and installation of the Hornsea One export cable system had been completed months ahead of schedule, delivering what it described as the longest AC offshore wind export cable system ever installed. The announcement confirmed that the high-voltage subsea export cables, manufactured by NKT at its facilities in Cologne and Karlskrona, together with the 38 km onshore cable route connecting three strings to the national grid at Killingholme, were fully manufactured and laid as part of the Hornsea 1 transmission assets.
11 Dec 2018Cable Landfall Complete
By 11 December 2018 Tideway BV, using sub‑contractor VBMS and the vessel Ndurance, had installed the three landfall cable sections at Horseshoe Point for Hornsea Project One, completing the shore-crossing and pull‑in operations that connect the offshore export cables to the 38 km onshore route forming part of the Hornsea 1 OFTO transmission link.
26 Nov 2018Stake Transaction
On 26 November 2018, Ørsted completed the divestiture of 50% of Hornsea 1 Holdings Ltd to funds managed by Global Infrastructure Partners. Following this sale, the Hornsea Project One wind farm and its associated transmission assets, including those destined to become the Hornsea 1 OFTO, were jointly owned on a 50/50 basis by Ørsted and Global Infrastructure Partners.
Global Infrastructure Partners (funds managed by GIP) acquired from Ørsted (50%)